Steps in the Process of Fertilization

Steps in the Process of Fertilization Fertilization is an essential process in sexual reproduction which involves the union of two specialized cells called the gametes to form a zygote. This then develops to form the new organism. During the process of fertilization innumerable number of sperms hit the surface of the eggs. But only one sperm succeeds in fertilizing it and the rest are repelled from the surface of the egg. This is done by the modification of cell envelope extracellular matrix besides altering the metabolic activity of the zygote or embryo. Various metabolic changes occur after the zygote is formed. This includes the respiratory burst hydrogen peroxide production activation of oxidases peroxidase alterations in the redox status changes in the activity of redox-sensitive transcription factors etc. Besides these an embryo-derived paf (1-o-alkyl-2-acetyl-sn-gylcero-3-phosphocholine) is synthesized and its release involves the binding to extracellular albumin which protects its enzymatic degradation (ONeill C , 1985). The change in the redox state affects the activity of redox-sensitive transcription factors that may alter gene expression patterns. Besides, this change in the metabolic status also, is responsible for the spatial differences in cell activity especially after compaction and major embryonic events such as fertilization genome activation and cellular differentiation (AJ Harvey et al, 2002). Multiple variations that occurs during this stage are found throughout phylogeny (Wessel G.M.et al., 2001; Shapiro B.M. et al, 1989). Three discrete steps are involved with the formation of extracellular barrier during the post-fertilisation stage (i.e. after zygote formation): Following cortical granule exocytosis an autoactivating serine protease separates plasma membrane attachments to the eggs vitelline layer facilitating the separation of this matrix from the egg surface (Haley S.A. and Wessel G.M., 1999). The structural components of the fertilization envelope (FE) primarily derived from the cortical granules (Wessel G.M. et al, 2001) self assemble into the vitelline layer network and form a distinct pattern of cytoskeleton like structures. (Chandler D.E. Heuser J. 1980). The cortical granule-derived enzyme ovoperoxidase is targeted to the FE by the tethering protein proteoliaisin (Somers C.E. et al, 1989). The structural proteins self-polymerise into fibers. This is followed by an increase in the ovoperoxidase activity in response to alkalization (Deits T.L. and Shapiro B.M., 1986) and an increase in the synthesis of hydrogen peroxide (Foerder C.A. et al 1978; Heinecke J.W. Shapiro B.M., 1989). Studies on nutrient uptake during fertilization have been done in various species(Leese Barton, 1984, Leese, 1991, Rieger, 1992, Rieger et al., 1992, Rieger Loskutoff, 1994, Gardner, 1999, Gopichandran Leese, 2003). However uptake of O2 is the major parameter that provides the required indication of overall metabolic status of a single zygote (Leese, 2003) as the production of ATP by oxidative phosphorylation a reaction in which O2 plays a major role (Thompson et al., 1996 Thompson, 2000 Leese, 2003). Furthermore the respiratory rates of single embryos is directly in correlation with quality (Abe Hoshi, 2003) and with survival following its transfer (Overstrà ¶m, 1992). When the production of the harmful reacting species eg., destructive oxygen species supersedes the bodys handling capacity through antioxidants, cellular damage occurs. This type of damage is the usual reason for most of the pathological states in animals, especially in nearly half of the infertile men. ROS bring their damage through various routes; the membrane of the sperm is damaged, which causes the motility rate of sperm to reduce and subsequently its inability to fuse with the egg during the fertilization process. ROS also alter the DNA of the sperm, leading to the improper genetic material getting transferred to the next generation. In spite of this, there is an inverse correlelation between the spermsa ability to produce ROS and their maturation. In the middle of the process of spermatogenesis, the cytoplasm of the sperm is lost due to its compaction (condensation) which is required for the elongation of sperm. This is witness from the study that immature teratozoospermic spe rms are featured by the presence of increased residues in cytoplasm in the mid-piece. Besides the cytotoxic damage caused by the levels of ROS in spermatozoa, hazardous oxygen metabolites produced by the leucocytes present in the ejaculate also damages it. This damage is more significant in the assisted conception therapy, where the contamination of the sperms washed, is presumed to the predominant factor determining the success rate of the fertilization, invitro. The so called reactive oxygen species ROS viz. H2O2 O2- · OH · etc affect the gametes and early reproductive events. ROS, produced by the peroxidation of the lipids, affects and changes the mitochondrial metabolism, besides producing more ROS. ROS are mainly known for their deleterious effects on spermatozoa and hence on male infertility (de Lamirande E et al, 1997, Sharma, RK Agarwal A, 1996, Shen, H Ong, C, 2000). Increased production of ROS has been associated with defects in the morphology of sperm (Aziz N et al 2004) inhibition of sperm motility (Armstrong JS et al, 1999, Parinaud J et al, 1997) fragmentation of sperm DNA (Donnelly ET et al, 1999) and premature capacitation (Villegas J et al, 2003). Further ROS also decreases the capacity for sperm-oocyte fusion efficiency and greatly inhibit the in vitro development of the embryo (Johnson MH et al, 1994, Guerin P et al, 2001, Mammoto A et al, 1996). More than six decades ago, it was discovered that the oxygen radicals (ROS) may have involved in the reproduction of human, especially men. (MacLeod, 1943). But the same was not studied to that extent in the case of female reproductive function, with only little works on pathological and physiological processes. Paszkowski observed that the selenium dependent glutathione peroxidase (SeGPx) was decreased in follicular fluids of women with no record of infertility (Paszkowski et al., 1995; Paszowski and Clarke, 1996). He also demonstrated that the levels of SeGPx were higher in those follicles which yielded oocytes that were successfully fertilized, compared to those follicles which yielded oocytes that failed to fertilize. Increased levels of hydrogen peroxide was found in the unfertilized oocytes also in fragmented embryos ( Yang et al., 1998). Whereas an increase in the antioxidant consumption was reported by Paszkowski and Clarke (1996) revealing an increase in the ROS activity, w hen poor quality embryos were incubated. Attaran et al (2000) observed a beneficial role of ROS, with its levels were high in the follicular fluid in IVF conception cycles compared to that of non-conception. Besides acting on sperm or oocytes separately, ROS were also reported to have its deleterious effect on sperm-oocyte fusion also. Studies reporting the fact the decrease in the levels of enzymes like catalase resulting in the loss of sperm motility. Many other studies produced a conclusive evidence for the production of ROS by human spermatozoa and showed that there was indeed an increase in the activity of ROS, in infertile men. If conventional method of invitro fertilization procedures were employed, even the spermatozoa whose DNA is damaged due to ROS, was able to fertilize the oocytes. Velocity measurements in the sperm motility studied under the impact of the ROS (generated by incubation with hydrogen peroxide) showed that the quality of sperm movement was significantly aff ected, but were motile, extremely; only the percentage motility was affected. Increased reactive oxygen species production was observed at 7 h and then at 24 h after IVF just before the first cleavage of the embryo. Increased oxidative activity and redox changes at the time of fertilization have been suggested to signal Ca2+ flux after the penetration of sperm. H2O2 besides being the substrate for ovoperoxidase is produced by a calcium-depending mechanism involving the reduction of one molecule of oxygen and the oxidation of two proton donors. Contrarily low levels of ROS has a positive effect on sperm functions (Bilodeau JF et al, 2000, de Lamirande E et al, 2003) binding of sperm to zona pellucida (Aitken RJ et al, 1989) and the development of embryo in bovine and other mammals (Harvey AJ et al, 2002 Guo Y et al, 2004, Harvey AJ et al, 2004). The concentration of ROS in both intracellular and extracellular are carefully regulated by enzymatic and nonenzymatic mechanisms and also by the presence of a detailed antioxidant defense mechanism in bovine oviductal tissues and fluids (Lapointe J et al 2003). Antioxidant genes especially a few glutathione peroxidases like GPx-1 Gpx-2 and Gpx-3 were differentially expressed along the oviduct. The major enzymes that are capable of metabolizing hydrogen peroxide (H2O2) belong to the family of GPx as well as the oviductal-catalase (Lapointe S et al, 1998, Brigelius-Flohe R, 1999). The concentration of oxygen that has to be utilized during the culture of embryos, influences the development and quality of the embryos. When the concentration of oxygen was reduced in the culture of mouse embryos, it altered the embryonic gene expression during the post-compaction stage. This has severe consequences on the fetal development of the mouse. (Deanne Feil, 2006). Furthermore blastocysts cultured under decreased O2 tension correlate more closely with in-vivo-recovered blastocysts than in vitro blastocysts cultured under normal O2 tension (Dumoulin JCet al, 1999; Yuan YQ et al, 2003; Johnson MH et al, 1994; Guerin P et al, 2001). The driving force for changes in the metabolic status of the zygote is the secretion of the cortical granules at least in sea urchins. The sea urchin embryo generates large amounts of H2O2 at the beginning of development of zygote and its levels are meticulously regulated to prevent any possible toxic effect. Because of this the sea urchin system provides greater insights into the control of reactive oxidants in biological systems. ROS can either positively or negatively affect the reproductive events in vitro. In the fertilization process the oviducts are the site of important processes that occur prior to implantation such as the maturation of oocyte in the initial stages of embryonic development (Harvey AJ et al 2002). They regulate the ROS levels to provide a proper environment for the gametes followed by their fertilization and the subsequent stages in the development of embryo. Vitamin E protects against the loss of the motility of the sperm through the peroxidation of lipids. Hence, supplementation of the same improved the motility of the sperm and enhanced the possibility of fertilization in asthenospermic invidicuals, even when the original sperm motility measured was only 20%. Spermatozoa exposed to PUFA showed an increase in its oxidative stress (Aitken, RJ, 2006). In particular, the oxidation of DHA- docosahexaenoic acid bound to phospholipid was shown to be one of the predominant factors that controls the mobility of the sperm in vitro. There is a marked cell to cell differences in the life span of sperm samples, which reflects in their susceptibility to lipid peroxidation. It is a well established fact that when a spermatozoa is subjected to oxidative stress, its membrane and the DNA is damaged through the membrane lipid peroxidation. The probability of this type of damaged spermatozoa will be able to fertilise the egg depends on the rate at which the functions of the sperm is lost. Till date, the research evidence shows that the motility of the sperm, its capacity to enter into acrosome reaction, its ability to integrate with vitelline membrane of the oocytes are all is prone to get affected by the oxidative stress. Of all the ROS, it is the superoxide anion and hydrogen peroxide that causes the deleterious damage to sperm capacitation and hence are the key mediators. The former contributes to the hyperactivated motility of the sperm, while the later is found to be associated with the tyrosine phosphorylation events in sperm capacitation. Current research have shown that the spermatozoa that are subjected to extreme oxidative stress using the method d escribed by Aitken RJ etal (1998) i.e, exposure to hydrogen peroxide and NADPH, have the capacity to reach the normal rate of fertilization with ICSI (intracytoplasmic sperm injection). The original postulate of the free radical hypothesis was that the ROS led to non specific modification of various biomolecules, such as proteins, lipids and nucleic acids. This is responsible for the etiology of the pathological condition that arises after that. The existence of oxidase activity was first documented while measuring oxygen consumption following fertilization (Warburg O., 1908). The increase in the oxygen consumption upon fertilization of sea urchin eggs is cyanide insensitive and produces H2O2 as the substrate for ovoperoxidase which crosslink the protective FE (Foerder C.A. et al, 1978). The assembly of ovoperoxidase into the fertilization envelope and the cross linking reaction are carefully regulated events that take place in ten minutes following gamete fusion (Weidman P.J. et al 1985). High oxygen concentrations are deleterious to early mammalian embryonic development (Thompson JG et al., 1990). Heinecke Shapiro have characterized an oxidase from unfertilized Stronglylocentrolus purpuratus eggs and had demonstrated its role as respiratory burst oxidase of fertilization. Their oxidase appears to be regulated by a protein kinase. It produces H2O2 when stimulated with Ca2+ and ATP and utilizes NADPH but not NADH as a source of reducing equivalents (Jay.W.Heinecke Bennett M. Shapiro, 1989; Li J Foote RH., 1993; Dumoulin JC et al., 1999). Some of the transcription factors including PEBP2 AP-1 p53 and NF-ÃŽÂ ºB are known to be regulated by the changes in the redox status and this regulation has been shown to occur through conserved cysteine residues in the DNA-binding regions of these proteins (Hirota K et al, 1997; Hirota K et al, 1999; Ueno M et al., 1999; Akamatsu Y et al., 1997). Role of à Ã¢â‚¬ °-3 fatty acids in fertilization Fatty acids are classified as: saturated monounsaturated and polyunsaturated (PUFA). There are two main classes of PUFA: n-3 (omega-3) and n-6 (omega-6); distinguished by the location of the first double bond i,e.,from the three or six carbon from the CH3 (methyl) end of the fatty acid. à Ã¢â‚¬ °-3 fatty acids are polyunsaturated fatty acids. Examples include ÃŽÂ ±-linolenic acid (ALA) eicosapentaenoic acid(EPA) and docosahexaenoic acid (DHA). The n-3 PUFAs are generated from ALA, found mostly in the chloroplasts of green plants and grass. These essential fatty acids can be converted to longer chain PUFAs, in liver, by desaturation and elongation enzymes, that is common to both. Fatty acid desaturase 2 (FADS2) is rate limiting (Gurr MI et al, 2002). The human cannot synthesize this, because they do not possess the required fatty acid desaturase enzymes and therefore have to be supplemented through diet. When the gene expression of this FADS2 enzyme is deleted the first step in the PUFA biosynthesis is stopped. This lack of PUFAs and eicosanoids did not interefere with viability or lifespan of female and male fads2-l mice, but resulted in sterility. Wilhelm S. etal (2008) demonstrated that phospholipids substituted with PUFA have a significant role in Sertolic cell polarity and blood-testis barrier, besides the gap junction network between the ovarian follicles granulose cells. They are implicated in various process in human, including reproduction, vision, neural development and growth (Gurr MI et al, 2002). For over a long period, these FAs have been implicated in the different stages of vertebrate fertilization. Either of n-6 or n-3 or both influence the reproductive processes through a heterogenous mechanisms, ranging from the providing the precursors for prostaglandin synthesis, steroid hormone biosynthesis, regulating the transcription factors involved. In ruminants, the pregnancy is established through the ovulation of the eligible oocytes, insemination at the right time and an adequate dosage of estradion and progesterone, during the luteal and follicular stages of the estrous cycle. Oocytes of cattle, when exposed to methyl palmoxirate to prevent the FA oxidation displayed low level of capcity to form blastocysts after fertilization. Moreover, the embryo have to develop completely to prevent luteolysis, which may occur by the interfereons production to inhibit up-regulation of the endometrial oxytocin receptors. Polyunsaturated fatty acids are also reported to modulate the function of the certain transcription factors that controls the gene expression and thus have a effect on the IC concentrations of the enzymes involved in the regulation of PG and steroid hormones synthesis. In bovine endometrial stromal cells and in lutenised granulose cells, both the omega-3 and 6 PUFAs are found to activate the protein kinase C, which activa tes the phosphodiesterase by phosphorylation. All these processes are affected by the dietary supplementationof PUFAs. Therefore changes in the PUFA sources subsequently reflects in the omega-3 and omega-6 content of the sperm. And these PUFAs are more susceptible to attack by the ROS as reported by various researchers. A schematic diagram showing a proposed mechanism in which the PUFAs generating the oxidative stress in human spermatozoa. High levels of poly unsaturated fatty acids in the spermatozoa of infertile human triggers the production of the ROS from a non mitochondrial source, (may be throughthe NADPH oxidase, NOX 5, influenzed by the calcium). Increased reactive oxygen species, ROS, then induces the peroxidation of lipids, which in turn shoots out the phospholipase A2, culminating in the release of more polysaturated fatty acids with subsequent generation of more ROS to perpetuate the oxidative stress. Dietary supplementation of n-3 PUFAs influence various aspects of fertility starting from conception and throughout the duration of pregnancy. (ESHRE Capri Workshop Group, 2006, Kind KL, et al, 2006). These n-3 PUFAs are incorporated in the phospholipids of the cell membrane and have their effects on membrane composition function, (Hong MY, 2002), ROS production (Hong MY, 2002 ,Watkins SM, 1998), membrane lipid peroxidation (Hawkins RA etal, 1998), regulators of transcription translation (Narayana BA et al 2001, Davidson LA2004), production of eicosanoids (Chapkins RS, 1991) and IC signal transduction (Ma D, 2004). Lupton JR (2004) had observed that these mentioned actions facilitate the n-3 PUFA-induced suppression of colon cancer. Similarly, alterations in the PG synthesis (mediated through the manipulation of the n-3 PUFAs) has profound effect on fertility, since PGs affect many aspects of fertilization, e.g., ovulation). Dietary supplementation of varying PUFA content to female cattle and to other mammals have found to alter the size and the number of ovarian follicles, the ovulation rate, the production of progesterone hormone by corpus luteum, the length of gestation and luteolysis timings. In male mammals, dietary PUFAs has demonstrated effect on sperm membrane PL composition and on the ability to fertilize (Abayasekara Wathes, 1999). For instance, sheep fed with diets containing high PUFAs delayed parturition (Baguma-Nibasheka et al. 1999). They also increased the incidence of placenta getting retained in cattle (Barnouin Chassagne 1991). High supplementation of ALA in diet, during the post partum period improved pregnancy rate in cattle (Kassa et al. 2002). Embryonic mortality was reduced through the suppression of uterine synthesis of prostaglandin F2alpha in cattle was brought about by altering the FA profile in their diets. This strategy of altering the FA profile in the diets, may be used to improve animal productivity by integrating the nutrit ion and reproductive management (Mattos R etal 2000). The fatty acid composition of both oocytes and sperm are responsible for the various observations in the study of the fertilization process in animals. The FA composition of the oocytes is specific for a given species both in terms of their abundance and their utilization. Among them, EPA, DHA and ARA have been associated in several stages of reproduction (Wathes DC etal 2007). Mature zebrafish oocytes fortify with ARA, indicating their capacity to synthesize eicosanoids for ovulation and follicular maturation. ARA along with LA was the most predominant PUFAs in oocytes of pig, sheep and cattle. (McEvoy etal 2000). Decreased ARA:EPA ratio in eggs and ovaries of fish have been reported as the reason for poor productivity in the captive broodstock (Pickova J, 2007, Cejas JR et al 2003). DHA along with EPA inhibited the gonadotrophin-mediated steroid hormone synthesis in cold and warm water fishes. These two highly unsaturated fatty acids (HUFA) act as regulator molecules in the maturat ion of those fish ovary (Mercure F et al 1995). Kim et al (2001) had observed that the quality of oocytes was influenced by the dietary FAs which changes the composition of granulose cells and oocytes. Based on those quality, the oocytes were divided in to grade1, 2, 3 etc. Kim also observed that there were differences in the FA composition between those grades of sheeps oocytes, which affected the oocytes competence, resulting in alterations in fertilization rate and developmental potential. Sheep fed with PUFAs had altered FA composition in their membrane PLs of cumulus cells, resulting in the alteration of the oocytes membrane properties (Zeron et al., 2002). Supplementation of n-6 and n-3 showed different reponses in reproduction (Wonnacot KE et al, 2010). Ewes fed with n-3 PUFAs prior to ovarian stimulation and follicular aspiration showed no changes in the follicle number and size. But follicular-fluid levels of progesterone were found to be greater and all the blastocycts (both treated and untreated with the stipulated diet ) contained increased levels of PUFAs, mostly ALA. Moreover, dietary supplementation of conjugated linoleic acid (CLA) to early-lactation dairy cows showed an improvement in their reproductive performance (MJ de Veth 2009). Cows fed with 18:3 FAs rich diets had a prolonged preovulatory follicle at insemination and larger volume of corpus luteum compared to those fed with MUFAs (Bilby TR, 2006). The deficiency of essential fatty acids affects the energy and fat metabolism, biosynthesis of PUFA, structure of cell membrane and signaling pathways in lipid resulting in incompatible life (Cunnane, 2003). Studies on fads2-/- mouse model had thrown light on the various effects of the deficiency of PUFAs, invididually,( ie, omega-3, omega-6 etc) and combined. In that study, FADS2 deficiency caused hypogonadism and sterility of male (azoospermia) female mice. Spermatogenesis is stopped in male fads2-/- mice occurred at the stage of round spermatids, leading to azoospermia. This is often caused by a damaged blood testis barrier BTB. BTB is formed by TJ and AJ protein complexes that are restricted to basolateral compartment of the more polarized sertoli cells (Fanning et al, 1998; Chapin et al, 2001; Ebnet et al, 2003). Similarly Thangavelu G etal (2007) have shown that the development of embryo was increased in Holstein cows that are fed with unsaturated fatty acids compared to those with saturated fatty acids. This shows that a diet rich in ÃŽÂ ±-linoleic acid facilitates the development of embryo when compared to that of linoleic or saturated fatty acids. Another observation which showed that, enriching the semen diluents with DHAs containing egg yolk prior to freezing did not enhance the sperm quality following thawing. In both human and in domestic animals, levels of the breakdown products of lipid peroxidation, such as malondialdehyde and 4-OHalkenal, had no correlation with the semen quality. But, studies on chickens showed that dietary supplementation with more PUFAs, decreased the antioxidant status and semen quality (i.e, sperm concentration and volume). In this context, the significance of the role of the non-enzymic antioxidant, vitamin-E (a chain breaking antioxidant), which reverses the negative effects caused by the PUFA supplementation is to be noted. Besides all the sources that had been mentioned in this introduction, the final source of oxidative stress is the sperm itself. Defective human sperms produce ROS, which is directly proportional to the extent of the impairment of the sperm function (Deluliis 2006). Another reason for sperm being a source for ROS is that some authors believe that they contain more amounts of unsaturated fatty acids, mainly DHA and AA (Ollero M, 2000). Their study demonstrated that exposing the human spermatozoa to various PUFAs resulted in the accelerated production of free radicals, subsequent to peroxidation of lipids and DNA damage. There is an abnormal retention of remnants of cytoplasm and a presence of increased levels of unsaturated fatty acids in the immature or defective human spermatozoa, which generated high levels of reactive oxygen species. PLA2 gets activated due to this peroxidation of lipid, which enhances the production of more free poly unsaturated fatty acid from the phospholipid fu rther increasing the production of ROS. In this situation, the fertilizing potential of spermatozoa under increased oxidative stress with concomitant low antioxidant status and more ROs production, will decrease dramatically as observed various researchers and in various species. Dietary n-3 PUFA affects reproductive processes including ovulation oocyte development and sperm levels motility. The in vivo morphology of oocytes is improved through a high supplementation of n-3 PUFA (zeron Y, 2002). PUFAs stimulate the generation of in vitro ROS (Aitken RJ et al 2006). In males the fatty acid composition of the sperm membrane influences their fertility and fertile men have much higher sperm levels of omega-3 FAs as compared to infertile men. Infertility and premature birth are two womens health issues where omega-3 levels are implicated. omega-3 supplementation decreased the clotting in the endometrial cells of the uterus and improved the implantation rates of fertilized eggs. Lower concentrations of spermatozoon DHA in asthenozoospermic men are not due to diet but to some type of metabolic difference (Conquer JA). Fouladi et al (2010) have shown that the ovary regulates the effects of alterations in plasma n-3 and n-6 FAs, resulting in only small effects on th eir developmental potential. The cessation of growth and some health problems in growing rats fed with low PUFAs were reversed after feeding the same with high PUFA sources rich in 18:3 ALA (Burr and Burr 1930). Reproduction in cattle is influenced more by the type of fats (ie. PUFA or MUFA) than with just fats as it is, reveals the importance of PUFAs in reproductive processes. This is more highlighted because ruminants extensively hydrogenate PUFAs, thereby limiting their supply for absorption in small intestine. Eicosanoids-independent mechanisms such as modulation of intracellular signaling pathways transcription factor activity and altered gene expression (Das UN., 2000; Dentin R et al, 2005; Simopoulos AP. et al, 2002). Fatty acids in the oocytes are utilized during its maturation and are incorporated into its cytoplasm (Ferguson EM et al, 2006; Kim JY et al, 2001). Changes in the n-3 PUFA levels in the diet alter the fatty acid composition of the oocytes and its surrounding environment affecting the oocytes maturation; modulate the development of follicles, ovulation, embryo development and developmental competence such as its ability to involve in fertilization. The changes in the diet profile for the n-3 PUFAs also had altered mitochondrial properties and increased the ROS levels in oocytes, suggesting a role for mitochondria in the impaired embryo development. Sarah et al (2008) studied the effect of diet supplementation of n-3 PUFA on the zygotes. Exposing the reproductive tract for a period of 22h (post hCG) found to increase the number of zygotes which are morphologically poor, especially when females were given a diet rich in n-3 PUFA. The in vivo-derived zygotes (which were morphologically normal) which were subjected to n-3 PUFA treatment failed to cleave and their development was delayed (Sarah et al, 2008). This was due to the impaired mitochondrial metabolism. Low and high levels of omega-3 concentrations in the blood have been implicated in various conditions. Hong et al. (2002) have observed n-3 FAs increase apoptosis in colonocytes when coincubated with butyrate. Eicosopentanoicacid increases oxidative stress leading to lipid peroxidation in Walker 256 rat tumor cells besides decreasing the mitochondrial membrane potential (Colquhoun A et al 2001.). in oocytes this change in mitochondrial membrane potential is observed to be a consequence of metabolic inhibitors (Van Blerkom J et al 2003) and have been correlated with developmental arrest in mouse two-cell embryo increased fragmentation (Acton BM et al 2004) and the rate of embryo development in the human (Wilding M et al 2001). Low omega-3 FA in blood leads to increase in menstrual pain. Lipids of the Oocyte are crucial for the energy requirement of the preimplantation zygote. They also participate in fertilization and in the subsequent cell differentiation (Amri et al., 1994). Oocytes that are oxidatively damaged have a low levels of PUFA and are unable to undergo fertilization (TarÄ ±Ãƒâ€šÃ‚ ´n et al., 1996). The levels of arachidonic acid and docosahexaenoic acid as well as lipid peroxidation in blood and seminal plasma of normozoospermic males from infertile couples compared with that of fertile volunteers indicate that systemic oxidative stress resulting in increased lipid peroxidation and an alteration in the fatty acid profile which may be responsible for infertility in men (Oborna I et al, 2009). The omega-6 or -3 fatty acids are the precursors for various metabolites produced in sperm and ovum which are necessary for fertilization. The precursors from omega-3 are less potent in generating ROS than omega-6. Therefore the gametes will be less affected by the effects of ROS under this condition. An imbalance in the omega-6-to-omega-3 ratio has been linked to various complications; like polycystic ovarian syndrome PCOS low sperm count etc. Treatment of cumulus-oocyte complexes (COCs) with ALA significantly increased the percentage of oocytes at the metaphase II an increase in the percentage of cleaved embryos the blastocyst rate and better -quality embryo compared with untreated controls while higher doses of it were detrimental (Waleed F et al, 2009). Thus the omega-3 FAs and the Redox regulators have multifarious roles before during and after the fertilization process. The role of the polyunsaturated fatty acids is important in both the physiology of sperm and ovum. This is highlighted by their key role in the maintaining the fluidity of the membrane of the sperm, which is needed for fertilization. Further, they are also a important part of the specific class of fucosylated slycosphigolipids, which are important for the male fertility. Besides these, they are also sources of alkoxyl and peroxyl radicals, to help these cells in the event of damages arising due to oxidative stress.

Family Assessment: Pratt and Cartwright Essay

The movie Tyler Perry: The Family That Preys is about Charlotte Cartwright (Kathy Bates) who is a white wealthy socialite and her dear friend Alice Pratt (Alfre Woodard), an African-American working class woman of high ideals. These two have enjoyed a lasting friendship throughout many years after all the ups and downs of life. Alice Pratt, a hard working Christian woman, who raised her two daughters Andrea (Sanaa Lathan) and Pam (Taraji Henson) while managing a simple diner of her own. While Charlotte owns a very profitable construction company in the area in which they both live. After graduation from college Andrea decides to work in a construction corporation owned by Charlotte Cartwright while her sister stays with Alice to work in the diner. Andrea is married to construction worker Chris (Rockmond Dunbar), who works in the same corporation as his wife but dreams of starting up his own business with his brother-in-law Ben (Tyler Perry). Throughout the movie Alice’s self-centered newlywed daughter Andrea is betraying her trusting husband Chris by engaging in a torrid affair with her boss and mothers best friend’s son William (Cole Hauser). While cheating on his wife Jillian (Kadee Strickland) with a string of ongoing dalliances with his mistress Andrea, William’s true focus is to replace Abby Dexter (Robin Givens) the COO of his mother’s lucrative construction corporation. Meanwhile, Alice’s other daughter Pam, a kind but no nonsense woman married to a hard working construction worker Ben, tries to steer the family in a more positive direction. While Alice travels with Charlotte on a road trip, the ambition and infidelity of William triggers a series of events that will affect relationships in both families. Suddenly, their lives become mired in turmoil as their adult children’s extramarital affairs, unethical business practices and a dark paternity secret derails family fortunes and unravel the lives of all involved. This movie is based in a modern day southern city, mostly likely Atlanta, Georgia, and revolves around two families from completely different financial, ethnic, and religious backgrounds. Both of the main characters are business owners but that is one of few things they have in common. Alice is woman who is very religious woman but it comes to Charlotte’s religion it is implied that she is not very religious at all. Both women own their own businesses. Alice who owns a diner is depicted to be struggling to get by; while Charlotte is the head of a major construction company has everything she always wanted and seems to want for nothing. The educational level of these characters is not stated, but it seems that any education has nothing to do with life experiences, their friendship, and how they run their businesses.   Alice is depicted to be a loving mother to her two daughters, while Charlotte comes off to be cold and harsh to her son and daughter-in-law.   Both women are the matriarch of their families and are without a husband. Charlotte lives in a big mansion that sits on top of a hill. While Alice lives in town. Both women seem to be well known in the community. Alice is known for her gentle kind heart and Charlotte for her ruthless and witty business practices. Both women have various family issues that seem to be ignored by them throughout the movie. This denial of the past seems to brew its ugly head towards the end of the movie and causes both women to confront the issues they have been putting on the back burner. Alice tries to pass on her religious and moral beliefs to both her daughters, but Andrea seems to have plans of her own. She is very resentful towards her mother for letting her father run off with another woman. She feels like her mother should have fought for her father instead of letting him run off with some woman and leaving them behind broke and struggling. Alice tries to explain to Andrea that what happened to them happened thirty years ago and the path she is going down by having an affair with William isn’t going to come out the way she expects.   Alice tells hers daughter that she needs to try and let go of what happened in the past and that William and her are from two different worlds. She tries to tell her daughter that he will not leave his wife and child for her and that she is ruining her life by have this affair. She tells her daughter that this was not how she raised her children. She tells her daughter that she can’t make herself happy bringing misery to others. Andrea tells her mother she’s going to enjoy the ride all the way. On the other hand Charlotte doesn’t trust her son or his intentions. It seems that he reminds her of his father. She makes this evident when her daughter-in-law Jillian comes to her and tells her that she found out that William is having an affair and it has been going on for years. She tells her daughter-in-law that she thinks she’s weak and that’s why she’s never really cared much for her. She explains to her daughter-in-law that in order to be a Cartwright woman she has to be able to en dour many things to enjoy the comforts that comes with the title. She tells her that his father did the same thing to her and Cartwright men are the kind of men that wonder and they have to be the kind of women that stay a few steps ahead. She explains to her that she now has the upper hand in the relationship and she holds all the cards and it’s up to her how she plays them. Both the Cartwright and the Pratt families have unhealthy coping skills and have big problems with denial. Whether is the way Charlotte interacts with her son and daughter in-law or the feelings of resentment that Andrea feels towards her mother for letting her father leaving them for another woman. Both of these families have unresolved issues that affect their everyday lives and the decisions that they make. This is depicted in the movie by various actions by its main characters. Things such as: Andrea’s unhealthy relationship with a married man, William going behind his mother’s back to try and steal the company from up under her or even Charlotte, unbeknownst to Alice, convincing her to take a road trip West after finding out she has been diagnosed with Early-Onset Alzheimer’s. Each person in this movie has a difficult problem with facing the truth that seems to be staring them right in the face. Each family’s core issues and their inability to resolve these problems are tearing them apart. I believe if it wasn’t for her Alice’s strong belief in God she would have buckled under the stress of her families poor decisions. Because she believed that when trouble hit if she stayed faithful and prayed that everything would work itself out. Whereas Charlotte believed that she controlled her own destiny through strategy and manipulation. The core differences between these two families are that the Cartwright’s believed that money and power are the most important things in life. Whereas the Pratt family, with exception of Andrea, believed that good things come to those who are faithful and good to others. References  ·Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Perry, T. (Director). (2008). Tyler Perry: The Family That Preys [Motion Picture].  ·Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   (2010). Retrieved April 28, 2010, from The Internet Movie Database:  Ã‚   http://www.imdb.com/title/tt114279  ·Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Friedman, M., Bowen, V., Jones, E. (2003). Family Nursing: Research, Theory, and Practice 5th edition.   Ã‚  Saddle River, New Jersey. Pearson Education, Inc.

Analysis of Nestle’s Business Environment

Company Overview Nestle, based in Switzerland, is the world’s leading food and nutrition company measured by revenues (Nestle, 2013). The company sells baby foods, breakfast cereals, coffee, confectionery, frozen food, pet foods, yoghurt and snacks through extensive distribution channels all over the world spreading out from facilities run by the company in over 100 countries. It owns several major consumer brands such as Stouffers, Nescafe, Kit-Kat, Carnation, Nestle water, among many others used by millions each year and which have established Nestle’s successful global brand image (Interbrand, 2013). This success can be attributed to clear focus and vision, as well as success in its continual differentiation and brand positioning which strengthen its market position (Jones, 2012). To sustain this success and thus maintain leadership in its market, the company must often audit and review its strategic position in light of changing factors in its business environment. This paper undert akes this strategic assessment employing the PESTLE framework of analysis. PESTLE analysis The PESTLE framework is a strategic tool used to measure market potential and situation of company (David, 2009). It focuses on factors in the external environment which encompass effects from the political, economic, social, technological, legal and environmental spheres. Political factors With operations spread out across the globe, Nestle is liable to political influences unique to various jurisdictions including applicable laws and regulations governing business operations, as well as stringent international health and safety requirements of significance in the food and nutrition sector, such as the ISO 9002 and HACCP (Hazard Analysis Critical Control Point) preventative food safety systems. The primary goal of these regulations is the protection of consumers from poor quality, potentially health averse/harmful products (Hill, 2006). The company has suffered challenges related to contamination of its products and poor quality supplies which have led to product recalls and market concern. This has hurt the company’s image and impacted sales as well as challenging it with regard to quality control (Nestle, 2013). The company has responded appropriately to address these, to ensure quality and safeguard confidence in its products (Jones, 2012). For successful engagement internationally, Nestle should endeavour to meet these expectations and to conform to the requisite legislations and regulations applicable. Economic factors The global business environment has recently been significantly hindered by economic setbacks due to downturn and global recession. These have adversely affected demand for products through its effect on consumer spending. However, recovery has been swift and the continuing globalization and consolidation has further enhanced growth and demand for product with the convergence in consumer tastes and preferences globally (Hanson et al., 2011). The rise in emerging market economies portends surplus buying power, as well as economies of scale which proffer added economic advantage (Vandewaetere, 2012). The leverage of huge resource capital and R&D capability into continual introduction and redesign of products enables Nestle to strengthen its competitive advantage. Through the localisation of operations in over 100 countries across the globe, the company manages to address the impact of foreign currency fluctuations on import and export aspects of trade (Jones, 2012). Social factors As a producer of finished consumer goods, Nestle is hugely dependent upon customer satisfaction and desirability of its product range to achieve success (Jones, 2012). The company, thus, chooses to embark on huge spending in its competitive sectors to maintain its brand image and to enhance product desirability. Competitive advantage in the sector requires continuous research and development leading to the frequent introduction of new products and redesign of products (Interbrand, 2013). This is a significant strength of Nestle and among the notable factors upon which its industry, sector or market leadership is based (Nestle, 2013). There is an increasing trend towards healthy eating which is increasing demand for healthier food products. This is laden with potential to affect product lines such as chocolate drinks (Jones, 2012). The company has taken specific steps such as the acquisition of specialised start-ups, and successful partnerships to meet the needs of health conscious co nsumers and thereby to take advantage of emerging market trends and opportunities (Vandewaetere, 2012). Nestle is therefore considered to be well adjusted to its market segments given its focus on this growth driver as well as its focus on popularly-positioned products which aims to provide a brand to meet every need. Its more than 8,000 brands enable it to achieve this strategic focus and to compete successfully against corporate rivals (Interbrand, 2013). Technological factors The fast pace of technological development and associated capabilities portend significant challenge for competitiveness in modern industry. Nestle has endeavoured to keep up through enormous investments in research and development to enhance its capability, as well as process efficiency which have enabled its successful differentiation and enhanced competitiveness (Nestle, 2013). However, the company still experiences challenges in its quality control with its inability to provide consistent quality in food products hurting company image and affecting sales (Jones, 2012). The company’s response in this regard has been quite appropriate enabling it to weather this challenge successfully. It has endeavoured to ensure quality in the foregoing and to safeguard confidence in its products through its seal of guarantee initiative (Interbrand, 2013). Environmental factors Nestle is involved in numerous programs aimed at making the company more eco-friendly which are inherent in its C SR initiatives. However, the company is criticised for its weak approach and over the effectiveness of their programs (Jones, 2012; Interbrand, 2013). With the scale of their operations across the globe and massive quantity of output, it is imperative that the company should enhance focus on its environmental impact which is a notable concern in modern industry. This factor has capacity to ruin reputations and affect performance (Hill, 2006). Legal factors Global operations in diverse jurisdictions require astute legal capabilities which Nestle seems to be endowed with. The company’s successful operations in over 100 countries attest to this giving it an edge in unmatched geographical presence in the industry. It also has notable competency in mergers and acquisitions which have enabled it to diversify and to successfully enter new markets thereby sustaining its competitive edge (Vandewaetere, 2012). Major challenges affecting the company Three major challenges are identified and explored to gauge their effect and to find out ways in which they might be addressed. Quality of products and supplies A major challenge with huge capacity for adverse impact on Nestle’s business potential concerns the quality of products delivered and thus the quality control schemes for its products. There have been instances of contamination of products as well as poor supplies which have led to a number of product recalls from the market (Interbrand, 2013). This challenge is fundamental particularly with regard to operations in the food and nutrition industry which is subject to stringent quality, as well as health and safety regulations. The company is subject to a high bargaining power of customers for the most part due to the availability of a wide range of substitute and alternative products in the market and fierce competition from worthwhile rivals (Carpenter and Sanders, 2007). Flouting of health and safety regulations also portends risk for operations in various jurisdictions and may lead to bans in markets and/or restrictions on the use of concerned products. This would definitely be a hindrance to business and would not only adversely impact sales but also would hurt company image and brand positioning which are vital intangible assets in a highly competitive market (Hanson et al., 2011). To reduce the negative impact of this challenge, the company needs to tighten its quality control procedures and schemes for products and also needs to enforce stringent procedures in the choice of suppliers and in the procurement of raw food items from them (Interbrand, 2013). This would not only guarantee conformance with requisite legislation but would also ensure that quality is maintained and adhered to across the entire supply chain. Also essential are measures to ward off loss of consumer trust and drop in confidence in products offered. Assurances in this regard are critical for the maintenance of brand image and reputation, and as well serve to guarantee product performance in the market (Jones, 2012; Vandewaetere, 2012). Weak implementation of eco-friendly initia tives Nestle pursues eco-friendly initiatives as constituent in its corporate social responsibility (CSR). Yet, these initiatives have been subject to extensive criticism over weakness in its approach and over the effectiveness of their programs (Vandewaetere, 2012). Environmentally friendly initiatives are particularly of concern for such entities as Nestle given their scale of operations across the globe and quantity of product output considering its 8,000 product brands (Interbrand, 2013). The primary objective of the company is the delivery of the best quality in everything from primary produce, choices of suppliers and transport, to recipes and packaging materials (Nestle, 2013). However, every stage in its supply chain is bound to have adverse environmental impact which is a notable concern in modern industry given the drive to environmental responsibility. Disregard of such concerns exposes the company to risks to reputation which could have a direct impact on performance (Ha nson et al., 2011). Increasing trend towards healthy eating With the rise in diseases associated with sedentary lifestyles, food choices, and eating habits, there has emerged global awareness of their impacts on individual health. This has engendered health consciousness and regard for choice of foods and their nutritive value or possible consequences. This has led to a trend towards healthy eating which continues to drive consumer preference and demand for healthier food products (Luthans and Doh, 2012). Such a trend is bound to affect popular product lines, such as chocolate drinks, that Nestle offers impacting demand and therefore market performance (Vandewaetere, 2012). In its consumer goods business, Nestle is hugely dependent upon customer satisfaction and desirability of its products to achieve success. It is thus immensely susceptible to market dynamics and trends such as eh above which it can do very little to control and manage (Kazem and Richard, 2008). The problem is further exacerbated by the emergence of social media and global networking through the internet which continues to drive globalization and which is causing a global convergence of consumer tastes and preferences (Hanson et al., 2011; Luthans and Doh, 2012). To counter this challenge, the company needs to embark on initiatives to develop a healthier range of products to cater to health conscious consumers and thereby to take advantage of the emerging trend and opportunities. Nestle should be keen to note the various dynamics and their impact on performance, and should develop flexibility which would enable faster response and adaptability to changes in the market (Jones, 2012). With a sound financial resource base, it is prudent for the company to pursue mergers and acquisitions, which it has done quite successfully, leveraging on its competence in that regard (Vandewaetere, 2012). This way, it is able to hasten its learning curve and guarantee success of initiatives (David, 2009) particularly in light of the fact that the company has an immense range of brands and a complex operational matrix which are in themselves quite a challenge to manage successfully. Conclusion Several factors affect Nestle in its international operations among them political, economic, social, technological, as well as environmental and legal factors, which are significant influences determining the success of operations in modern business environment. Three particular challenges are identified as having substantial impact on Nestle’s operations and business potential. They include: quality of products and supplies which portends loss of confidence in product; the company’s weak implementation of eco-friendly initiatives which are essential not only to check the environmental impact, but also serve as proof for goodwill to society; and, the increasing trend towards healthy eating which is a concern for future competitiveness of the company’s products. These challenges should be addressed to guarantee success of products in markets, as well as overall competitiveness. References Carpenter, M., and W., Sanders, (2007). Strategic Management: A Dynamic Perspective. Harlow: Pearson Prentice Hall. David, F. R. (2009), Strategic management: concept and cases (12th Ed). Pearson, NJ: Prentice Hall. Hanson, D., M., Hitt, R., Ireland, & R., Hoskisson, (2011). Strategic Management: Competitiveness and globalisation (Asia-Pacific, 4th Ed). South Melbourne, Australia: Cengage Learning Hill, C., (2006) International Business: Competing in the Global Economy, (7th Ed) Maidenhead: McGraw-Hill Interbrand (2013). Best Global Brands 2012. Accessed 1/9/2014 from: http://www.interbrand.com/en/best-global-brands/2012/Best-Global-Brands-2012.aspx Jones, S., (2012). Strategic Management at Nestle. Accessed 1/9/2014 from: http://www.articlesbase.com/management-articles/strategic-management-at-nestle-5907881.html Kazem, C., and L., Richard, (2008). Sustainable competitive advantage: towards a dynamic resource-based strategy. East London Business School: University of East London, UK. Luthans, F., and J., Doh, (2012). International Management: Culture, Strategy, and Behaviour, (8th Ed). Maidenhead: McGrawHill Nestle, (2013). Annual Report – 2013 (English). Accessed 2/9/2014 from: http://www.nestle.com/asset-library/Documents/Library/Documents/Annual_Reports/2013-Annual-Report-EN.pdf Vandewaetere, B., (2012). Personal Interview – 28th November, 2012: Responsible for European Affairs, Nestle. Accessed 2/9/2014 from: www.Nestle.com

Wedding Speech Marymount Dance Department - 967 Words

May 5, 2016 was one of the happiest moments of my entire life. That was the day made possible for me to see a live performance. It was my very first time and have to admit I was super exciting entering the auditorium. Marymount Dance Department presented the 2016 Spring Repertoire. I felt so proud walking in as a dancer watching a live performance. The show began and my heart skipped a beat. Marymount’s Dancers At Work presented in a beautiful manner that drove into their movements. There were numerous moves that we did that they presented in their routine. I was most proud when I saw one colored dancer in the piece Regality. She performed incredibly well I began to move along with her. There was uses of high jumps, releve’s, plià ©Ã¢â‚¬â„¢s, pirouette’ and many more. I was not sure what the dancers were doing, but all I Knew was that I needed to be on that stage doing exactly what they did. The multiple dances that were performed moved me in such ways words can not explain. I am a beginner in Ballet, modern, jazz, tap, ballroom, and heels. Studying dance while going to see a live performance is crucially. I know I want to dance because Dance 105 became the eye opener to different expressions of the art form. However, the dancers allowed me to solidify that decision and go into the field of dance. I was moved more by the emotions rather than the actual dance moves. As the dancers performed, I was startled by the energy and love that the dancers brought to the platform. I could notShow MoreRelatedStephen P. Robbins Timothy A. Judge (2011) Organizational Behaviour 15th Edition New Jersey: Prentice Hall393164 Words   |  1573 Pagesretrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, One Lake Street, Upper Saddle River, New Jersey 07 458, or you may fax your request to 201-236-3290. Many of the designations by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in