Ghrelin Accelerates In Vitro Maturation of Bovine Oocytes

Ghrelin, apart from its metabolic role, is nowadays considered as a basic regulator of reproductive functions of mammals, acting at central and gonadal levels. Here, we investigated for possible direct actions of ghrelin on in vitro maturation of bovine oocytes and for its effects on blastocyst yield and quality. In experiment 1, cumulus oocyte complexes (COCs) were matured in the presence of four different concentrations of ghrelin (0, 200, 800 and 2000 pg/ml). In vitro fertilization and embryo culture were carried out in the absence of ghrelin, and blastocyst formation rates were examined on days 7, 8 and 9. In experiment 2, only the 800 pg/ml dose of ghrelin was used. Four groups of COCs were matured for 18 or 24 h (C18, Ghr18, C24 and Ghr24), and subsequently, they were examined for oocyte nuclear maturation and cumulus layer expansion; blastocysts were produced as in experiment 1. The relative mRNA abundance of various genes related to metabolism, oxidation, developmental competence and apoptosis was examined in snap‐frozen cumulus cells, oocytes and day‐7 blastocysts. In experiment 1, ghrelin significantly suppressed blastocyst formation rates. In experiment 2, more ghrelin‐treated oocytes matured for 18 h reached MII compared with controls, while no difference was observed when maturation lasted for 24 h. At 18 and 24 h, the cumulus layer was more expanded in ghrelin‐treated COCs than in the controls. The blastocyst formation rate was higher in Ghr18 (27.7 ± 2.4%) compared with Ghr24 (17.5 ± 2.4%). Differences were detected in various genes’ expression, indicating that in the presence of ghrelin, incubation of COCs for 24 h caused over‐maturation (induced ageing) of oocytes, but formed blastocysts had a higher hatching rate compared with the controls. We infer that ghrelin exerts a specific and direct role on the oocyte, accelerating its maturational process.     

Dietary supplementation of essential oils and lysozyme reduces mortality and improves intestinal integrity of broiler chickens with necrotic enteritis

The objective of this study was to investigate the individual and combined effects of essential oils (EO; comprised of thymol and carvacrol) and lysozyme on experimental NE in broiler chickens. A total of 320 1-day-old chicks were randomly assigned to five treatment groups: no-challenge control (NC), NC + C. perfringens challenge (CC), CC + 120 mg/kg of EO, CC + 100 mg/kg of lysozyme, and CC + 120 mg/kg of EO + 100 mg/kg of lysozyme. The results showed that EO or lysozyme decreased the mortality, alleviated the gut lesions, inhibited the liver Enterobacteriaceae carriage, and increased the villus height of the ileum compared with CC (p < .05), although the proliferation of C. perfringens in the ileum was not inhibited (p > .05). Moreover, EO or lysozyme was found to decrease the ileal concentration of sialic acid and the Mucin2 mRNA expression (p < .05). However, the blend of EO and lysozyme did not display significant effect on the NE-associated mortality or gut damage in contrast with CC (p > .05). In conclusion, these findings suggest the similar protective effects of EO and lysozyme in NE-associated mortality and intestinal impairment, but their blend did not exhibit ameliorative effect.     

Contrasting effects of heat shock during in vitro maturation on development of in vitro‐fertilized and parthenogenetic bovine embryos

This study investigated the influence of heat shock during in vitro maturation on embryo development following in vitro fertilization (IVF) or parthenogenesis (Part). Immature bovine cumulus–oocyte complexes were exposed to heat shock (41.0°C) during the first 12 hr of in vitro maturation (IVM), followed by 12 hr at 38.5°C. Control group consisted of in vitro maturation for 24 hr at 38.5°C. Oocytes were in vitro‐fertilized or activated with ionomycin and cultured in vitro for 192 hr post‐in vitro insemination or parthenogenetic activation (hpia). There was an interaction (p < .01) between temperature of IVM and method of oocyte activation (IVF or Part) for cleavage at 48 hpia. Heat shock had a negative impact (p < .01) on cleavage of IVF embryos, whereas no (p > .05) effect was found in the Part embryos. Embryo development towards blastocyst stage at 168 and 192 hpia decreased in both IVF and Part embryos derived from heat‐shocked oocytes. Heat shock increased (p < .05) the apoptotic index in Part blastocysts, but no effect (p > .05) was found in IVF counterparts. Heat shock also down‐regulated the expression of AQP3 (p < .01) and up‐regulated the expression of HSP70.1 (p < .01) in Part blastocysts, whereas it down‐regulated the expression of ATP1A1 (p < .05) in IVF blastocysts. In conclusion, the effects of heat shock during IVM on early embryo cleavage and blastocyst apoptosis are influenced by the method of oocyte activation and expression of some genes can be disturbed in embryos derived from heat‐shocked oocytes.     

Use of oxytocin to attain cervical dilation for transcervical embryo transfer in sheep

The aim of this work was to determine whether a cervical dilation protocol (CDP) composed of only oxytocin can be used to perform transcervical (non-surgical) embryo transfer in sheep (NSET) without affecting the viability of the corpus luteum (CL). Likewise, we evaluated whether a cervical transposing test with a Hegar dilator (CT Hegar test), performed at oestrous time, could be used to screen ewes for NSET (greater or lower chances to transpose the cervix). For that, oestrous and ovulation synchronization was performed in 25 Santa Inês ewes to induce the dioestrous condition. Animals went through the following CDP in a crossover design: E + OX, oestradiol benzoate (100 µg intravenously [IV]) and oxytocin (100 IU IV); OX, oxytocin (100 IU IV); and SAL, saline solution (IV). Using a Hegar dilator, cervical transposing attempts were performed at oestrous (D0) and dioestrous time (D8). The viability of the CL (morphology, luteal blood flow and progesterone values) was evaluated by ultrasonography (colour Doppler and B-mode) and by serum progesterone measurement from D7 to D13. The cervical transposing rate was lower for the SAL group (64%; 16/25; p < .05) and did not differ between the E + OX (88%; 22/25, p > .05) and OX (84%; 21/25, p > .05) groups. No treatment affected the CL viability. The CT Hegar test showed a high sensitivity (85.7%–93.3%), satisfactory accuracy (72%–84%), low false-negative rate (6.7%–14.6%), but high false-positive rate (46%–66.7%). In conclusion, a CDP protocol composed exclusively of oxytocin can lead to good cervical transposing rates and does not affect the viability of the CL. In addition, a screening test (CT Hegar) performed at oestrus can identify ewes for which cervical transposing will likely not occur at NSET.     

Effects of meiotic inhibitors and gonadotrophins on porcine oocytes in vitro maturation,fertilization and development

This study evaluated the effect of three reversible meiotic inhibitors (MINs) and their interaction with gonadotrophins (Gns) on the meiotic maturation and developmental competence of porcine oocytes. In experiment 1, the oocytes were matured for 22 hr in the presence or absence of dbcAMP (1 mM), cycloheximide (7 μM) or cilostamide (20 μM) with or without Gns, and for an additional 22 hr in the absence of MINs and Gns. At 22 hr of maturation, regardless of the presence of Gns, a higher proportion (p < .001) of oocytes cultured in the presence of MINs were effectively arrested at the germinal vesicle stage compared with the oocytes cultured without MINs. At 44 hr of maturation, the proportion of oocytes that reached MII was higher (p < .05) in groups with Gns compared with groups without Gns. In experiment 2, oocytes that were matured as in experiment 1 were inseminated and cultured for 7 days to evaluate fertilization parameters and blastocyst formation. Only oocytes from the dbcAMP + Gns group had higher (p < .05) efficiency of fertilization compared with the other treatment groups. The presence of dbcAMP during maturation also increased (p < .05) blastocyst formation and efficiency of blastocyst formation in both the presence and absence of Gns. These results indicate that the interaction of Gns with the tested MINs improved meiotic progression. In addition, regardless of supplementation with Gns, the presence of dbcAMP during the first maturation period increased and even doubled the capacity of oocytes to develop to the blastocyst stage.     

Effect of pterostilbene on development,equatorial lipid accumulation and reactive oxygen species production of in vitro-produced bovine embryos

The pterostilbene (PT) molecule is a phytoalexin with a reducing effect on reactive oxygen species (ROS) and with a capacity to block lipogenesis. However, the potential reducing effects of PT on equatorial lipid accumulation and ROS have not yet been elucidated for in vitro-derived bovine embryos. The present study evaluated the effects of concentrations of 3, 1, 0.33, 0.11 μM PT, and a vehicle group on the percentage of cleaved embryos, embryos with more than 6 cells, percentage of blastocyst on Day 7 and 8, percentage of transferable embryos on Day 7, the cell count and relative concentration of lipids. In the second experiment, the effects of 0.33 μM PT and a vehicle group within two different O₂ environments (5% and 20%) were evaluated for ROS generation and the percentage of Day 8 blastocysts. In the first experiment, no significant differences were found between the treatments with PT and the vehicle group (p > .05) concerning the percentage of cleaved embryos and embryos with more than 6 cells. Lipid reduction was observed in the groups treated with PT versus the vehicle group (p < .05). The vehicle group showed a higher rate of blastocyst production on Days 7 and 8 (p < .05) and an increase in the percentage of transferable embryos on Day 7 compared to the PT treatment groups (p < .05). Cell counts were not significantly different between treatments with PT and the vehicle group (p > .05). In the second experiment, the O₂ concentration did not significantly affect ROS generation (p > .05); however, the groups treated with PT (0.33 μM) had a reduction in ROS (p < .05). The O₂ concentration also did not significantly affect the rate of blastocyst production on Day 8 (p = .7696). Future research should be conducted to ascertain whether the reduction of lipids could enhance the cryopreservation and post-thaw viability of PT-treated embryos.     

The effects of phospholipase C on oestradiol and progesterone secretion in porcine granulosa cells cultured in vitro

Granulosa cells play important roles in the regulation of ovarian functions. Phospholipase C is crucial in several signalling pathways and could participate in the molecular mechanisms of cell proliferation, differentiation and ageing. The objective of this study was to identify the effects of phospholipase C on the steroidogenesis of oestradiol and progesterone in porcine granulosa cells cultured in vitro. Inhibitor U73122 or activator m‐3M3FBS of phospholipase C was added to the in vitro medium of porcine granulosa cells, respectively. The secretion of oestradiol decreased after 2 hr, 8 hr, 12 hr, 24 hr and 48 hr of treatment with 500 nM U73122 (p < .05) and decreased after 2 hr of treatment in the 500 nM m‐3M3FBS addition group (p < .05). The secretion of progesterone increased after 4 hr of treatment with 500 nM U73122 (p < .05) and increased after 2 hr and 8 hr of treatment in the 500 nM m‐3M3FBS addition group (p < .05). The ratio of oestradiol to progesterone decreased at each time point, except 8 hr after the addition of 500 nM U73122 (p < .05). The ratio of oestradiol to progesterone decreased after 2 hr (p < .05) of treatment with 500 nM m‐3M3FBS. In genes that regulate the synthesis of oestradiol or progesterone, the mRNA expression of CYP11A1 was markedly increased (p < .05), and the mRNA expression of other genes did not change significantly in the U73122 treatment group, while the addition of m‐3M3FBS did not change those genes significantly despite the contrary trend. Our results demonstrated that phospholipase C can be a potential target to stimulate the secretion of oestradiol and suppress progesterone secretion in porcine granulosa cells cultured in vitro, which shed light on a novel biological function of phospholipase C in porcine granulosa cells.     

The Importance of Having Zinc During In Vitro Maturation of Cattle Cumulus–Oocyte Complex: Role of Cumulus Cells

The aim of this study was to investigate the influence of zinc (Zn) on the health of cumulus–oocyte complex (COC) during in vitro maturation (IVM). Experiments were designed to evaluate the effect of Zn added to IVM medium on: DNA integrity, apoptosis, cumulus expansion and superoxide dismutase (SOD) activity of cumulus cells (CC). Also, role of CC on Zn transport during IVM was evaluated on oocyte developmental capacity. DNA damage and early apoptosis were higher in CC matured with 0 μg/ml Zn compared with 0.7, 1.1 and 1.5 μg/ml Zn (p < 0.05). Cumulus expansion did not show differences in COC matured with or without Zn supplementation (p > 0.05). Superoxide dismutase activity was higher in COC matured with 1.5 μg/ml Zn than with 0 μg/ml Zn (p < 0.05). Cleavage and blastocyst rates were recorded after IVM in three maturation systems: intact COCs, denuded oocytes with cumulus cells monolayer (DO + CC) and denuded oocytes (DO). Cleavage rates were similar when COC, DO + CC or DO were matured with 1.5 μg/ml Zn compared with control group (p > 0.05). Blastocyst rates were significantly higher in COC than in DO + CC and DO with the addition of 1.5 μg/ml Zn during IVM (p < 0.01). Blastocyst quality was enhanced in COC and DO + CC compared with DO when Zn was added to IVM medium (p < 0.001). The results of this study indicate that Zn supplementation to IVM medium (i) decreased DNA damage and apoptosis in CC; (ii) increased SOD activity in CC; (iii) did not modify cumulus expansion and cleavage rates after in vitro fertilization; (iv) improved subsequent embryo development up to blastocyst stage; and (v) enhanced blastocyst quality when CC were present either in intact COC or in coculture during IVM.     

The effects of vitrification after equilibration in different concentrations of cryoprotectants on the survival and quality of bovine blastocysts

This study assessed the effects of cryoprotectant concentration during equilibration on the efficiency of bovine blastocyst vitrification and the expression of selected developmentally important genes. In vitro produced bovine blastocysts were equilibrated in either 7.5% ethylene glycol (EG) + 7.5% DMSO (Va group) or in 2% EG + 2% DMSO (Vb group) then vitrified on Cryotop® sheets in 16.5% EG + 16.5% DMSO + 0.5M sucrose. After warming, embryos were cultured for 48 hr. Re‐expansion, hatching, and the numbers of total and membrane damaged cells were compared among vitrified groups and a control. There was no significant difference between the vitrified groups in survival, cell numbers and the extent of membrane damage. Vitrification increased the number of membrane‐damaged cells in both groups, however, in a greater extent in the Vb group. Vitrification increased (p < .05) the expression of the HSP70 gene in Va but not in Vb embryos. The expression of IGF2R, SNRPN, HDAC1, DNMT3B, BAX, OCT4, and IFN‐t genes were the same in control and vitrified groups. In conclusion, the concentration of cryoprotectants during equilibration did not affect survival rates; however, normal cell numbers could be maintained only by equilibration in 15% cryoprotectants which was associated with increased HSP70 expression.     

Corpus luteum vascularization during the maternal recognition of pregnancy in llamas (Lama glama)

The aim of this study was to characterize corpus luteum vascularization and its association with plasma progesterone concentration in early stages of pregnancy, when maternal recognition of pregnancy is expected to occur. In all animals, both plasma progesterone concentration and corpus luteum vascularization increased from Day 6 to Day 8 post-mating and afterwards in non-pregnant llamas they started to decrease to reach basal levels around Days 12 to 14 post-mating, while in pregnant animals, both variables remained elevated until the end of the study. A lineal positive relationship between corpus luteum vascularization and plasma progesterone concentration was observed in pregnant (r² = .46, p < .0001) and non-pregnant llamas (r² = .66, p < .0001). Pregnant animals showed higher plasma progesterone concentration and corpus luteum vascularization than the non-pregnant ones from Day 12 post-mating until the end of the study (p ˂ .05 and p ˂ .01, respectively). These results suggest that maternal recognition of pregnancy should occur before Day 12 post-mating in order to expand luteal lifespan, maintaining corpus luteum vascularization and progesterone production. Also, the assessment of CL vascularization area could be a useful and non-invasive method for early pregnancy diagnosis due to its association with plasma progesterone concentration.     

Presence of chlorogenic acid during in vitro maturation protects porcine oocytes from the negative effects of heat stress

Chlorogenic acid (CGA) is known to protect oocytes from oxidative stress. Here we investigated the effects of CGA on porcine oocyte maturation under heat stress and subsequent embryonic development after parthenogenetic activation. For in vitro maturation (IVM) at 41.0°C (hyperthermic condition), supplementation of the maturation medium with 50 μM CGA significantly improved the percentage of matured oocytes and reduced the rate of apoptosis relative to oocytes matured without CGA (p < .05). CGA treatment of oocytes during IVM under hyperthermia tended to increase (p < .1) percentage of blastocyst formation after parthenogenesis and significantly increased (p < .05) the total cell number per blastocyst relative to oocytes matured without CGA. For IVM at 38.5°C (isothermic condition), CGA significantly improved the rate of blastocyst development compared with oocytes matured without CGA (p < .05), but did not affect oocyte maturation, apoptosis rate or the number of cells per embryo. Omission of all antioxidants from the IVM medium significantly reduced the rate of oocyte maturation, but the rate was restored upon addition of CGA. These results demonstrate that CGA is a potent antioxidant that protects porcine oocytes from the negative effects of heat stress, thus reducing the frequency of apoptosis and improving the quality of embryos.     

In vitro studies of Norwegian Red bovine semen immobilized and cryopreserved in alginate solid gel network

Development of new semen cryopreservation techniques improving sperm survival and ensuring availability of viable spermatozoa for a prolonged time‐period after AI is promising tools to reduce sensitivity of timing of AI and enhance overall fertility. The SpermVital^® technology utilizes immobilization of bull spermatozoa in a solid network of alginate gel prior to freezing, which will provide a gradual release of spermatozoa after AI. The objective of this study was to compare post‐thaw sperm quality and in vitro sperm survival over time of Norwegian Red bull semen processed by the SpermVital^® (SV) technology, the first commercialized production line of SpermVital^® (C) and by conventional procedure applying Biladyl^® extender (B). Post‐thaw sperm motility was not significantly different between SV, C and B semen (p > .05). However, sperm viability and acrosome intactness were higher for SV than C and B semen (p < .05). Small differences in DNA quality were observed (p < .05). Sperm viability after storage in uterus ex vivo was higher for SV than for C semen (p < .05). Furthermore, sperm survival in vitro over time at physiological temperature was significantly higher for SV semen than C semen as well as B semen during the incubation period of 48 hr (p < .05). In conclusion, the SpermVital^® technology is improved and is more efficient in conserving post‐thaw sperm quality and results in higher sperm viability over time in vitro for SV than for C and B semen.     

Effect of oak (Quercus persica) acorn level on apparent digestibility,ruminal fermentation,nitrogen balance and urinary purine derivatives in pregnant goats

The aim of this experiment was to investigate the effect of dietary oak (Quercus persica) acorn (OA) level on dry matter intake (DMI), apparent nutrient digestibility, nitrogen (N) utilization, ruminal fermentation, protozoa population and urinary purine derivatives (PD) during the last 60 days of goat pregnancy. Twenty‐four multiparous pregnant goats (41.7 ± 2.3 kg BW) were assigned to one of three experimental diets consisted of control diet (C, without OA) and diets containing 20 (OA₂₀) or 40 g/100 g of OA (OA₄₀) on a DM basis in a completely randomized block design. Goats fed OA₄₀ had lower DMI (p < .01), DM (p < .01), OM (p < .01) and NDF (p < .05) digestibility, ruminal NH₃‐N concentration (p < .01), N intake (p < .01) and N retention (p < .01). Crude protein digestibility and ruminal acetate and total volatile fatty acid (VFA) concentration were lower in animals fed OA‐contained diets (p < .01), whereas ruminal propionate concentration was higher in goats fed the C diet (p < .01). Animals fed OA₄₀ had higher faecal N excretion and lower urinary N excretion (p < .01). Urinary PD was lower in goats fed diets containing OA in relation to those fed the C diet (p < .01). Total protozoa population decreased linearly with increasing OA level in the diet (p < .05). These results suggest that feeding OA, especially high level, has negative impacts on DMI, nutrient digestibility, VFA concentration, N retention and urinary PD excretion that may have adverse effects on metabolism and performance of pregnant goats.     

Lipid and protein oxidation levels in spermatozoa and seminal plasma of Asian Elephants (Elephas maximus) and their relationship with semen parameters

Peroxidation damage to spermatozoa and seminal plasma has an important role in sperm quality. Thus, the objective of this study was to determine the levels of lipid and protein oxidation in spermatozoa and seminal plasma of Asian elephants (Elephas maximus) with varying percentage of progressive motility. Lipid and protein oxidation was measured by the thiobarbituric acid‐reactive species (TBARS) assay and the 2, 4‐dinitrophenylhydrazine (DNPH) carbonyl groups assay, respectively. Fresh semen samples were collected from Asian elephants and classified according to the percentage of motile spermatozoa into good (>60%) and poor (≤20%) motility. Results revealed that seminal plasma malondialdehyde (MDA) and seminal plasma protein carbonyls (PCs) were significantly higher in poor motility than in good motility (p < .05). The MDA and PC levels in seminal plasma were negatively correlated with the percentages of progressive motility (p < .05). In addition, the negative correlation between sperm concentration and seminal plasma MDA level was investigated (p < .05). The sperm viability was also negatively correlated with sperm PC level (p < .05). This study indicated that lipid and protein oxidation has deleterious effect on semen quality of Asian elephants.     

The effects of luteinizing hormone as a suppression factor for apoptosis in bovine luteal cells in vitro

The fate of the corpus luteum, a transient endocrine gland formed and degraded during an oestrous cycle, is decided by various physiological factors, such as luteinizing hormone (LH). As a stimulator of progesterone, LH is known to maintain corpus luteum functional and structural integrity by inhibiting apoptosis, a programmed cell death. Therefore, we aim to investigate its action during the mid-luteal phase hypothesized that LH suppresses the death mechanism of bovine luteal steroidogenic cells (LSC) by analysing the expression of proteins involved. Cultured bovine LSC obtained from corpus luteum were treated for 24 hr with recombinant TNF and IFNG in the presence or absence of LH. The result showed that LH proved to have a protective effect by increased cell viability (p < .05) and prevented DNA fragmentation (p < .05), as demonstrated by the WST-1 colorimetric assay and TUNEL assay. Expression analysis of mRNA and protein levels showed that LH altered the expression of BCL2 (p < .05), CASP3 (p < .05), FAS (p < .05), and BAX (p < .05) to support cell survival. In conclusion, our study suggests that LH prolongs the corpus luteum life span through the anti-apoptotic mechanism by increasing cell viability and suppressing apoptosis-related genes and protein expression.     

Effects of the E1 activating enzyme UBA2 on porcine oocyte maturation,apoptosis, and embryonic development in vitro

The purpose of this study was to investigate the effect of the E1 activating enzyme UBA2 on the expression of the SUMO-1 protein during in vitro maturation (IVM) of pig oocytes and embryonic development. In the 5 μg/ml UBA2 treatment group, the expression of the anti-apoptotic gene Bcl-2 and the embryo cleavage rate was significantly increased, while the proapoptotic gene Bax was significantly reduced. When 10 μg/ml UBA2 was added, the in vitro maturation rate, blastocyst rate, and SUMO-1 protein content of oocytes increased significantly (p < .05), and the expression of proapoptotic gene Caspase3 was significantly decreased (p < .05), while the viability of cumulus cells was extremely significantly reduced (p < .01). In summary, UBA2 can regulate the content of the SUMO-1 protein in mature pig oocytes in vitro, which in turn affects the maturation rate of oocytes, expression of apoptosis genes, cumulus cell viability, and the development of embryos after fertilization.     

Improving ovulation in gilts using anti-inhibin serum treatment combined with fixed-time artificial insemination

For successful batch farrowing, porcine oestrus and ovulation must be synchronized using fixed-time artificial insemination (FTAI). However, exogenous gonadotropins, which are currently used in FTAI, negatively affect gilt ovulation. Here, we aimed to improve sexually mature gilt superovulation efficiency using passive immunization against inhibin during FTAI. Altrenogest-treated gilts were challenged with 10 ml anti-inhibin serum (AIS group, n = 6), 1,000 IU pregnant mare serum gonadotropin (PMSG group, n = 6), or 10 ml goat serum (control group, n = 6). Gilts in the AIS and PMSG groups were inseminated according to the FTAI protocol, and gilts in the control group were inseminated during natural oestrus. When PMSG was replaced by AIS during FTAI of gilts, ovulation rate and embryos recovered were significantly greater in the AIS group as compared to the other two groups (p < .05). Especially the average number of 6–8-cell embryos in the AIS group was significantly higher than that in the PMSG group (p < .01). Moreover, the blastocyst number in the AIS group was significantly higher than that in the PMSG group and the control group (p < .05). But there was no significant difference in the blastocyst number between the PMSG group and the control group (p > .05). Besides, plasma levels of estradiol-β (E2) and progesterone (P4) were significantly greater in the AIS group as compared to the other two groups on Day 23 and D 27, respectively (p < .01). In summary, we devised an improved high-yield FTAI protocol for sexually mature gilts using AIS; this protocol had a greater superovulation efficiency than the FTAI using PMSG.     

The relationship between acrosome reaction and polyunsaturated fatty acid composition in boar sperm

This study investigated the relationship between acrosome reactions and fatty acid composition with respect to fertility in boar sperm. The acrosome reaction was induced more than 85% by 60 mM methyl-beta-cyclodextrin (MBCD), and plasma membrane integrity was significantly reduced dependent on the MBCD level in boar sperm (p < .05). The acrosome-reacted sperm exhibited significantly higher saturated fatty acids (SFAs) and lower polyunsaturated fatty acids (PUFAs) composition compared to the non-acrosome reaction group (p < .0001). In addition, the PUFAs, C22:5n-6 (docosapentaenoic acid [DPA]; p < .01) and C22:6n-3 (docosahexaenoic acid [DHA]; p < .0001) were significantly decreased, and cleavage and blastocyst formation of oocytes were significantly (p < .0001) decreased in acrosome-reacted sperm relative to non-acrosome-reacted sperm. Moreover, acrosome reaction was positively correlated with SFAs, whereas negatively correlated with PUFAs, of the PUFAs, the DPA (p = .0005) and DHA (p = <.0001) were negatively correlated with the acrosome reaction. Therefore, these results suggest that the PUFAs composition of sperm is closely involved in acrosome reaction in pigs.