Molecular, enzymatic responses and in vitro embryonic developmental competency of heat-shocked buffalo embryos co-cultured with granulosa cells monolayer

The present study was designed to establish a suitable alternative approach to mitigate the adverse effect of high culture temperature on in vitro embryo development and the related molecular response in buffalo. Pre-cultured granulosa cells (GCs) were used as a monolayer during in vitro embryo culture until day 8 (day of fertilization = D0). Post fertilization, presumptive embryos were randomly assigned into two culture conditions: embryos cultured in the presence of GCs monolayer under normal culture temperature (N: 38.5 °C; GEN group) or heat shock (H: 40.5 °C; GEH group) and their counterpart groups of embryos cultured without GCs (EN and EH groups). Additionally, two groups of GCs monolayer were cultured without embryos up to day 8 under 38.5 °C (GN) or 40.5 °C (GH) for further spent culture media enzymatic analyses. Heat shock was administered for the first 2 h of culture then continued at 38.5 °C until day 8. The results indicated that under heat treatment, GCs enhanced (P ≤ 0.05) embryo cleavage and development (day 8) rates, which were comparable to the embryos cultured at 38.5 °C. On the molecular level, blastocysts of the GEH group showed similar expressions of metabolism-regulating genes (CPT2 and SlC2A1/GLUT1) and an antioxidant gene (SOD2) when compared to the blastocysts of the EN group. The relative expression of HSP90 was significantly up-regulated under heat shock and/or co-culture conditions. However, HSF1 expression was increased (P ≤ 0.05) in the GEH group. No statistical differences were observed among the study groups for the pluripotency gene NANOG, and stress resistance transcript NFE2L2. Regarding the enzymatic profile, the concentrations of SOD, total protein, and MDA were decreased (P ≤ 0.05) in the GEH group compared to the cultured GCs without embryos (GH group). In conclusion, GCs as a monolayer have a beneficial impact on alleviating heat stress at the zygote stage through the regulatory mechanisms of metabolic activity, defense system, and heat shock response genes.

Melatonin administration during the first half of pregnancy improves the reproductive performance of rabbits: Emphasis on ovarian and placental functions

This study was designed to investigate the roles of melatonin administration during different sensitive windows of the first half of pregnancy in the function and gene expression of the ovary and placenta, hormone profile, and pregnancy outcomes in rabbits. Four equal experimental groups of 20 rabbits each were used. The first (FW), second (SW), and third (F + SW) groups comprised rabbits that orally received 0.7-mg melatonin/kg body weight during the first week, second weeks, and during both weeks of pregnancy; and the fourth group served as the control group (C). The total number of visible follicles significantly increased in all melatonin-treated groups compared with that in the C group. In all melatonin-treated groups, the number of absorbed fetuses was significantly reduced, whereas the weights of embryonic sacs and fetuses were higher than in the C group. The placenta efficiency was significantly increased in the F + SW group compared with that in the C group, followed by the SW group, whereas no significant difference in the placenta efficiency was found between the FW and C groups. Melatonin treatments significantly improved the expression of antioxidants, gonadotropin receptors, and cell cycle regulatory genes in the ovary, whereas only FW treatment upregulated steroidogenic acute regulatory gene. Compared with the C and FW groups, melatonin treatments during the SW and F + SW significantly upregulated the expression of most genes in the placenta. The concentrations of estradiol were significantly higher in the SW and F + SW groups than in the FW and C groups. The concentrations of progesterone were significantly increased in the FW group compared with those in the C and SW groups, whereas the F + SW group showed intermediate values. The litter size and weight at birth significantly increased in all melatonin-treated groups compared with those in the C group. The second week of pregnancy seems to be a sensitive window for melatonin actions during pregnancy. Thus, melatonin administration during the second week of pregnancy can be effective in improving pregnancy outcomes in rabbits.

Molecular and physiochemical evaluation of buck semen cryopreserved with antioxidants

The current study evaluated the physiochemical quality and gene expression profile of post-thawed buck semen after supplementation with antioxidants [melatonin (M), L-carnitine (LC), cysteine (Cys), LC+M, M+Cys, LC+Cys, LC+Cys+M] in comparison with the non-treated control group. Physical as well as biochemical characteristics of semen were evaluated following freezing and thawing. Transcript abundance of six selected candidate gens was profile using quantitative real-time PCR. The data demonstrated significant enhancement of post-freezing total motility, progressive motility, percentage of live sperm, CASA parameters, plasma membrane and acrosome integrity in all groups supplemented with Cys, LC, M+Cys, and LC+Cys compared with the control group. The biochemical analysis of semen indicated that semen groups supplemented with LC and LC+Cys, recorded increased levels of GPX and SOD that were coupled with up-regulation of antioxidant genes (SOD1, GPX1, and NRF2) and mitochondrial transcripts (CPT2 and ATP5F1A). Moreover, H2O2 level and DNA fragmentation percentage were reduced compared to other groups. In conclusion, supplementation of Cys alone or in combination with LC positively improved the post-thaw physiochemical properties of rabbit semen through activation of bioenergetics-related mitochondrial genes and cellular antioxidant defense mechanism.

Effects of Ascorbic Acid on Maturation Rate, Morphology, and Gene Expression of Vitrified In Vitro Matured Dromedary Camel Oocytes

In vitro embryo generation, cryopreservation, and embryo transfer are examples of assisted reproductive technologies that can be used to improve camel genetic performance and fertility. The aim of this study was to investigate the impact of ascorbic acid supplementation to in vitro maturation media on the maturation rate, morphology, and gene expression of fresh and vitrified in vitro matured dromedary camel oocytes. In the current study, 810 oocytes of excellent and good quality were in vitro matured in maturation medium (TCM-199 + 10 ug/ml follicle stimulated hormone + 10% fetal calf serum + 100 IU/ml Pregnant mare serum + 50 μg/ml gentamycin) without any additives to act as a control group (C) and with 50 μg/ml ascorbic acid group (AA) and incubation in a CO2 incubator (38.5 ̊C, 5% CO2, 20% O2 and 95% humidity) for 40 hours. In vitro matured dromedary camel oocytes with the first polar body (n = 210) in C group and AA group (n = 250) were placed in basic medium (BM) and then placed in vitrification solution1 (VS1) for one minute, followed by the transfer of oocytes to VS2 (double concentration of VS1, containing 20% Ethyl Glycol (EG) and +20% Dimethyl sulfoxide) for 30 seconds. Oocytes were then loaded into sterile 0.25 ml straws and stored in liquid nitrogen for 7-10 days. The normal fresh and vitrified /thawed in vitro matured dromedary camel oocytes were kept in RNA later at a -80°C freezer for gene expression analysis. The maturation rate of dromedary camel oocytes in the in vitro matured AA group was significantly higher than that of the C group. The percentage of normally recovered vitrified/thawed oocytes was higher in the in vitro matured with ascorbic acid (VAA) than in the control (VC) group. The expression pattern of the SOD1 gene and GDF9 gene was upregulated in fresh AA and VAA groups than in the fresh C and VC groups. The profile of the SOD1 gene was more abundant in the vitrified/thawed oocytes VAA group than in the VC group. All vitrified/thawed groups, whether control or ascorbic acid supplemented, had lower levels of SOD1, GDF9, and BMP15 expression, compared to the fresh groups. In conclusion, the supplementation of the maturation medium with ascorbic acid has an increased maturation rate, and normal morphology of vitrified/ thawed oocytes which was linked with upregulation of SOD1, GDF9 genes expression.

Co-expression of candidate genes regulating growth performance and carcass traits of Barki lambs in Egypt

Sheep are considered one of the main sources of animal protein in Egypt and the producers of sheep mutton eagers to find biological criteria for selecting fast-growing lambs that reach market weight early. Therefore, the present study aimed to find a link between the expression profile of selected candidate genes with growth performance and carcass traits of Barki lambs. Thirty-eight Barki lambs were kept and fed individually after weaning till 12 months of age and were divided into 3 groups according to growth performance (fast, intermediate, and slow-growing). Three samples were taken from different body tissues (eye muscle, liver, and fat tail) of each group, directly during slaughtering and stored at − 80 °C until RNA isolation. Real-time PCR was used to profile selected candidate genes (RPL7, CTP1, FABP4, ADIPOQ, and CAPN3) and GAPDH was used as a housekeeping gene. The results indicated that the final body weight was significantly (P ≤ 0.05) greater in the fast (49.9 kg) and intermediate (40.7 kg) compared to slow-growing animals (30.8 kg). The hot carcass weight was heavier (P ≤ 0.05) in the fast and intermediate-growing (24.57 and 19.07 kg) than slow-growing lambs (15.10 kg). The blood profiles of T3 and T4 hormones in addition to other parameters such as total protein, total lipids, and calcium level showed no clear variations among different experimental groups. At the molecular level, our data demonstrated upregulation of genes involved in protein biosynthesis (RPL7), fatty acid oxidation (CPT1), and lipolysis (FABP4) in the fast and intermediate-growing lambs in all studied tissues which facilitate protein accretion, energy expenditure, and fatty acid partitioning required for muscle building up. Moreover, the expression profile of the gene involved in muscle development (CAPN3) was increased in fast and intermediate-growing compared to slow-growing lambs in order to support muscle proper development. On the other hand, a candidate gene involved in lipogenesis (ADIPOQ) was expressed similarly in fat and liver tissues; however, its expression was increased in muscles of fast and intermediate-growing lambs compared to slow-growing animals. In conclusion, the current study indicated that the expression profile of genes involved in metabolic activities of liver, muscle, and adipose tissue is linked with the growth performance of lambs although no variations were detected in blood parameters. This provides an evidence for the importance of co-expression of these genes in body tissues to determine the final body weight and carcass characteristics of Barki sheep.

Genetic Features of Reproductive Traits in Bovine and Buffalo: Lessons From Bovine to Buffalo

Bovine and buffalo are important livestock species that have contributed to human lives for more than 1000 years. Improving fertility is very important to reduce the cost of production. In the current review, we classified reproductive traits into three categories: ovulation, breeding, and calving related traits. We systematically summarized the heritability estimates, molecular markers, and genomic selection (GS) for reproductive traits of bovine and buffalo. This review aimed to compile the heritability and genome-wide association studies (GWASs) related to reproductive traits in both bovine and buffalos and tried to highlight the possible disciplines which should benefit buffalo breeding. The estimates of heritability of reproductive traits ranged were from 0 to 0.57 and there were wide differences between the populations. For some specific traits, such as age of puberty (AOP) and calving difficulty (CD), the majority beef population presents relatively higher heritability than dairy cattle. Compared to bovine, genetic studies for buffalo reproductive traits are limited for age at first calving and calving interval traits. Several quantitative trait loci (QTLs), candidate genes, and SNPs associated with bovine reproductive traits were screened and identified by candidate gene methods and/or GWASs. The IGF1 and LEP pathways in addition to non-coding RNAs are highlighted due to their crucial relevance with reproductive traits. The distribution of QTLs related to various traits showed a great differences. Few GWAS have been performed so far on buffalo age at first calving, calving interval, and days open traits. In addition, we summarized the GS studies on bovine and buffalo reproductive traits and compared the accuracy between different reports. Taken together, GWAS and candidate gene approaches can help to understand the molecular genetic mechanisms of complex traits. Recently, GS has been used extensively and can be performed on multiple traits to improve the accuracy of prediction even for traits with low heritability, and can be combined with multi-omics for further analysis.

Adaptive and Biological Responses of Buffalo Granulosa Cells Exposed to Heat Stress under In Vitro Condition

Simple Summary

The pertinent consequences of global warming substantially affect both animal productivity and fertility. Noteworthy, tropical and subtropical animal breeds are productively suited to hot climate conditions. Therefore studying the physiological changes accompanying high temperature, especially in tropically adapted species such as buffalo, will help in understanding the mechanisms that the animal use to accomplish the necessary functions efficiently. Concerning fertility-related activity, granulosa cells are important for the regulation of ovarian function and the completion of oocyte maturation. In this study, the buffalo granulosa cells were examined for their viability, physiological and molecular responses under in vitro heat stress conditions. Buffalo granulosa cells displayed different adaptive responses, at the physiological and molecular levels, to the different heat stress conditions. At 40.5 °C, granulosa cells exhibited a functional persistence compared to the control and other heat-treated groups. These results will provide insights into ways that tropically adapted breeds may be able to maintain better reproductive function when exposed to heat stress compared to temperate breeds.

Abstract

The steroidogenesis capacity and adaptive response of follicular granulosa cells (GCs) to heat stress were assessed together with the underlying regulating molecular mechanisms in Egyptian buffalo. In vitro cultured GCs were exposed to heat stress treatments at 39.5, 40.5, or 41.5 °C for the final 24 h of the culture period (7 days), while the control group was kept under normal conditions (37 °C). Comparable viability was observed between the control and heat-treated GCs at 39.5 and 40.5 °C. A higher release of E2, P4 and IGF-1 was observed in the 40.5 °C group compared with the 39.5 or 41.5 °C groups. The total antioxidant capacity was higher in response to heat stress at 39.5 °C. At 40.5 °C, a significant upregulation pattern was found in the expression of the stress resistance transcripts (SOD2 and NFE2L2) and of CPT2. The relative abundance of ATP5F1A was significantly downregulated for all heat-treated groups compared to the control, while TNFα was downregulated in GCs at 39.5 °C. Expression analyses of stress-related miRNAs (miR-1246, miR-181a and miR-27b) exhibited a significant downregulation in the 40.5 °C group compared to the control, whereas miR-708 was upregulated in the 39.5 and 40.5 °C groups. In conclusion, buffalo GCs exhibited different adaptive responses, to the different heat stress conditions. The integration mechanism between the molecular and secretory actions of the GCs cultured at 40.5 °C might provide possible insights into the biological mechanism through which buffalo GCs react to heat stress.

In Vivo and In Vitro Evaluation of Bull Semen Processed with Zinc (Zn) Nanoparticles

Defective sperms cause fertilization failure under both in vivo and in vitro conditions. Therefore, providing optimal conditions during semen storage is a prerequisite for maintaining viability. The current study investigated bull semen quality in vitro and in vivo when zinc (Zn) nanoparticles were used as antioxidant during semen processing and cryopreservation. In total, 32 ejaculates were collected from four Holstein bulls. All ejaculates were pooled and diluted with Bioxcell-extender containing 0 (control group), 10^-6, 10^-5, 10^-4, 10^-3, and 10^-2 M of Zn nanoparticles. Several physical and biochemical sperm parameters were determined after freeze-thawing process. In vitro embryo development rate and pregnancy rate were monitored after in vitro fertilization or artificial insemination using semen treated with Zn nanoparticles. Plasma membrane integrity was improved (P < 0.05) in bull semen treated with 10^-6 M (69.3%), and 10^-2 (62.4%) of Zn nanoparticles compared to untreated group (51.3%). In addition, proportions of live spermatozoa with active mitochondria were increased (P < 0.05) in semen supplemented with Zn nanoparticles at concentration of 10^-6 M (67.3%), and 10^-2 (85.3%) compared to control group (49.8%). Moreover, the level of MDA was lower (P < 0.05) in semen with Zn nanoparticles at 10^-6 M (2.97 mol/mL) and 10^-2 (2.7 mol/mL) concentrations than control semen samples (3.77 mol/mL). However, sperm total and progressive motility, sperm viability, DNA fragmentation, and pregnancy rate were not affected by treatment of semen with Zn nanoparticles. On the other hand, supplementation of in vitro maturation media with 10^-6 M Zn nanoparticles has increased blastocyst rate (P < 0.05) compared to other experimental groups, while addition of Zn nanoparticles-treated sperm during in vitro fertilization did not affect embryo development rate. In conclusion, supplementation of Zn nanoparticles to semen has improved its quality without affecting embryo development rate in vitro. However, in vitro embryo development rate was increased when Zn nanoparticles were supplemented to IVM media. This support the notion of Zn nanoparticles beneficial action on improving bovine gametes quality without affecting pregnancy rate.

Physiological and molecular aspects of heat-treated cultured granulosa cells of Egyptian buffalo (Bubalus bubalis)

The physiological and molecular responses of granulosa cells (GCs) from buffalo follicles were investigated when there were in vitro heat stress conditions imposed. The cultured GCs were heat-treated at 40.5 °C for 24, 48 or 72 h while GCs of the control group were not heat-treated (37 °C). There were no differences in viability between control and heat-treated groups. There was an upward trend in increase in E₂ secretion as the duration of heat stress advanced, being greater (P ≤ 0.05) for the GCs on which heat stress was imposed for 72 as compared with 24 h. In contrast, P₄ release was less (P ≤ 0.05) from GCs heat-treated for 48 h than those cultured for 24 h and GCs of the control group. The relative abundance of ATP5F1A and SOD2 mRNA transcripts was consistent throughout the period when there was imposing of heat stress to sustain mitochondrial function. The relative abundance of CPT2 transcript was less in heat-treated GCs than in GCs of the control group. There was a greater relative abundance of SREBP1 and TNF-α mRNA transcripts after 48 h of heat-treatment of GCs than GCs of the control group. In conclusion, the results from the current study indicate buffalo GCs cultured when there was imposing of heat stress maintained normal viability, steroidogenesis and transcriptional profile. The stability of antioxidant status and increased transcription of genes regulating cholesterol biosynthesis and stress resistance may be defense mechanisms of buffalo GCs against heat stress.

Effect of flunixin meglumine and aspirin administration on conception rate and estrous cycle characteristics of Egyptian Baladi cows during hot season

The current investigation aims to evaluate the effects of flunixin meglumine (FM) and aspirin as non-steroid anti-inflammatory drug (NSAID) administration on estrous cycles characteristics and conception rate of Egyptian Baladi cows during hot season. In the first phase, 30 cows were divided into 3 groups, 10 cows for each treatment. The first group was treated with FM at the rate of 1.1 mg/kg body weight (BW) intramuscular, while the second group was administrated aspirin solution orally at the rate of 50 mg/kg BW. The third group was assigned as control (CG) that has no treatment. The FM group was administrated on day 14 after mating, while aspirin was given on day 14 and day 15 post-mating. All cows were mated naturally after showing estrus signs. Pregnancy diagnosis was carried 60 days after mating by rectal palpation. In the second phase, cows were monitored for estrus behavior by visual observation twice a day. The length of normal estrous cycles was 20, 23, and 22 days in cows treated with FM, aspirin, and control cows, respectively. There was no significant effect of treatment on the length of normal estrous cycles in Egyptian cows (P < 0.05). Proportions of long cycles in Egyptian cows that treated with FM or aspirin and control were 75, 67.7, and 57.1%, respectively. Short cycles were completely absent in cows that treated with FM or aspirin, but it was 29% in CG. Mounting behavior and tail rising were not detected in CG compared to 0 and 33% in FM or 25 and 33% in aspirin treated cows, respectively. Conception or pregnancy rate were 60, 40, and 30%, respectively, in FM, aspirin treated, and CG. Treatment cows whether FM or aspirin group did not influence (P < 0.05) progesterone concentration during the 14 days and 21 days from estrous cycle in pregnant and non-pregnant Egyptian Baladi cows than CG. In conclusion, the results of this study clearly indicated beneficial effect of FM and aspirin administration on intense of displayed estrous behavior and conception rate of Egyptian Baladi cows during the hot season.

Transcriptome profile and association study revealed STAT3 gene as a potential quality marker of bovine gametes

The present study was aimed to investigate differences in molecular signatures in oocytes derived from Holstein-Friesian heifers with different genetic merit for fertility, euthanized during day 0 or day 12 of the estrous cycle. Moreover, association between single nucleotide polymorphisms (SNPs) of ODC1 and STAT3 genes and bull fertility traits was investigated. The gene expression patterns were analyzed using cDNA array and validated with quantitative real-time polymerase chain reaction (PCR). The result revealed that several genes have shown not only to be regulated by fertility merit but also by the day of oocyte recovery during the estrous cycle. The STAT3 gene was found to be upregulated in oocytes recovered from animals with high fertility merit at both day 0 and day 12. Some other genes like PTTG1, ODC1 and TUBA1C were downregulated at day 0 and upregulated at day 12 in high, compared with low, fertility merit recovered oocytes. In contrast, the transcript abundance of TPM3 was upregulated at day 0 and downregulated at day 12 in high, compared with low, fertility merit recovered oocytes. In addition, ODC1 and STAT3 were found to be associated (P < 0.05) with sperm quality traits as well as flow cytometry parameters. Therefore, the expression of several candidate genes including ODC1 and STAT3 was related to the genetic merit of the cow. In addition polymorphisms in these two genes were found to be associated with bull semen quality.

Oocyte maturation with royal jelly increases embryo development and reduces apoptosis in goats

Royal jelly (RJ) was supplemented to goat oocyte in vitro maturation (IVM) medium at three different concentrations (2.5, 5, and 10 mg/ml). Maturation rate, embryo cleavage, and blastocyst rate were recorded. Gene expression of apoptosis-related transcripts was investigated in matured oocytes. Percentage of oocytes that reached MII-stage was increased in RJ-treated groups compared to the control group. Glutathione (GSH) content of mature oocytes was enhanced when RJ was added to IVM medium at any supplementation compared with control. Percentage of cleaved embryos and blastocysts was higher in the RJ-treated groups at a concentration of 5 than in the 2.5 mg/ml and control group. Total number of cells per blastocyst was not different in the control and RJ-treated group at 5 mg/ml. However, number of apoptotic cells per blastocyst was higher in the control group than in the RJ-treated group at 5 mg/ml. Expression profile of Bax, and p53 was down-regulated while Bcl-2 was up-regulated in oocytes treated with RJ at 5 and 10 mg/ml compared with the control group. Addition of RJ at concentrations of 5 mg/ml improved embryo production through increasing maturation rate. RJ seems to improve the IVM microenvironment by reducing expression of genes inducing apoptosis, enhancing GSH content, and reducing incidence of apoptosis in blastocysts.

Integrated ovarian mRNA and miRNA transcriptome profiling characterizes the genetic basis of prolificacy traits in sheep (Ovis aries)

BACKGROUND

The highly prolific breeds of domestic sheep (Ovis aries) are globally valuable genetic resources for sheep industry. Genetic, nutritional and other environmental factors affect prolificacy traits in sheep. To improve our knowledge of the sheep prolificacy traits, we conducted mRNA-miRNA integrated profiling of ovarian tissues from two pure breeds with large (Finnsheep) vs. small (Texel) litter sizes and their F1 crosses, half of which were fed a flushing diet.

RESULTS

Among the samples, 16,402 genes (60.6% known ovine genes) were expressed, 79 novel miRNAs were found, and a cluster of miRNAs on chromosome 18 was detected. The majority of the differentially expressed genes between breeds were upregulated in the Texel with low prolificacy, owing to the flushing diet effect, whereas a similar pattern was not detected in the Finnsheep. F1 ewes responded similarly to Finnsheep rather than displaying a performance intermediate between the two pure breeds.

CONCLUSIONS

The identification and characterization of differentially expressed genes and miRNAs in the ovaries of sheep provided insights into genetic and environmental factors affecting prolificacy traits. The three genes (CST6, MEPE and HBB) that were differentially expressed between the group of Finnsheep and Texel ewes kept in normal diet appeared to be candidate genes of prolificacy traits and will require further validation.

Identification and characterization of miRNAs in the ovaries of a highly prolific sheep breed

Until recently, there have been few studies concerning miRNAs or miRNA-mediated biological processes in sheep (Ovis aries). In the present study, we used a deep-sequencing approach to examine ovarian miRNAs and the mRNA transcriptomes in two ewes of a highly prolific breed, Finnsheep. We identified 113 known sheep miRNAs, 131 miRNAs conserved in other mammals and 60 novel miRNAs, the expression levels of which accounted for 78.22%, 21.73% and 0.05% of the total respectively. Furthermore, the 10 most abundantly expressed miRNAs in the two libraries were characterized in detail, and the putative target genes of these miRNAs were annotated using GO annotation and KEGG pathway enrichment analyses. Among the target genes, intracellular transducers (SMAD1, SMAD4, SMAD5 and SMAD9) and bone morphogenetic protein (BMP) receptors (BMPR1B and BMPR2) were involved in the transforming growth factor β (TGFβ) signaling pathway in the reproductive axis, and the most significant GO terms were intracellular part (GO:0044424), binding (GO:0005488) and biological_process (GO:0008150) for cellular component, molecular function and biological process respectively. Thus, these results expanded the sheep miRNA database and provided additional information on the prolificacy trait regulated through specific miRNAs in sheep and other mammals.

Developmental competence of equine oocytes: impacts of zona pellucida birefringence and maternally derived transcript expression

In the present study, equine oocytes were classified into groups of presumably high and low developmental competence according to cumulus morphology, as well as oocyte ability to metabolise brilliant cresyl blue (BCB) stain. All oocytes were evaluated individually in terms of morphometry, zona pellucida birefringence (ZPB) and relative abundance of selected candidate genes. Oocytes with an expanded cumulus (Ex), representing those with presumably high developmental competence, had a significantly thicker zona (18.2 vs 17.3µm) and a significantly higher ZPB (64.6 vs 62.1) than oocytes with a compacted cumulus (Cp). Concurrently, oocytes classified as highly developmentally competent (BCB+) had a significantly thicker zona (18.8 vs 16.1µm) and significantly higher ZPB (63.1 vs 61.3) compared with oocytes classified as having low developmental competence. Expression of TFAM, STAT3 and CKS2 was significantly higher in Ex compared with Cp oocytes, whereas expression of COX1, ATPV6E and DNMT1 was lower. Together, the data reveal that developmentally competent equine oocytes are larger in size, have higher ZPB values and exhibit a typical genetic signature of maternally derived transcripts compared with oocytes with lower in vitro developmental competence.

Production of female bovine embryos with sex-sorted sperm using intracytoplasmic sperm injection: efficiency and in vitro developmental competence

The production of embryos with a preselected sex sperm is important in the livestock industry. In this study, we examined the efficiency of producing female embryos by intracytoplasmic sperm injection (ICSI) with flow cytometry sorted (ssICSI) and unsorted (usICSI) bovine sperm, and their developmental competence in vitro. For comparison, bovine embryos were also produced by in vitro fertilization (IVF) with sorted (ssIVF) and unsorted (usIVF) bovine sperm. The semen used in this study was from a bull selected for its high fertility and blastocyst developmental competence among four bulls. We first examined and compared pronuclear (PN) formation and cleavage rates of the produced embryos among the treatment groups. Our results demonstrated that PN formation rates (judged by two pronucleus [2PN]) and cleavage rates in ssIVF group (23.1% and 43.6%) were lower than those in the usIVF (71.1% and 71.6%), usICSI (73.1% and 92.8%) and ssICSI (75% and 79.1%) groups, respectively (P < 0.05). Moreover, the blastocyst formation rate in the ssIVF group was less than those in the usIVF, usICSI, and ssICSI groups (2.7% vs. 30.2%, 28.7% and 24.7%, respectively; P < 0.05). Importantly, we reported that the blastocyst formation rate in the ssICSI group was similar to that in the usICSI group, which indicated that ICSI can rescue the damage introduced to sperm by flow cytometry-mediated sex-sorting. Of note, we achieved a blastocyst formation rate in the ssICSI group to be comparable with the usIVF group. We then examined embryo quality by counting the number of normal and apoptotic cells in blastocysts. It was found that, despite the fact that blastocyst formation rate in the ssIVF group was significantly lower than those in the usIVF, usICSI and ssICSI groups, there was no difference in total and apoptotic cell numbers among these groups (P > 0.05). Finally, karyotyping analysis demonstrated that the proportion of female embryos in the ssICSI and ssIVF groups was 100%, whereas it was 58.8% and 57.8% in the usIVF and usICSI groups, respectively. In conclusion, ICSI with flow cytometry sorted bovine sperm provides an alternative approach to produce embryos with predetermined sex.

Mitochondrial content and gene expression profiles in oocyte-derived embryos of cattle selected on the basis of brilliant cresyl blue staining

The aim of this study was to investigate the developmental rate, lipid and mitochondrial distribution and gene expression in oocyte-derived embryos selected on the basis of brilliant cresyl blue (BCB) staining. Lipid content and mitochondrial distribution in Day 8 blastocysts were evaluated by fluorescence intensity, while gene expression was analyzed by real-time PCR. The proportion of blastocysts (30.9%) was greater (P<0.05) in BCB+ than in BCB- oocytes (13%) but not different (P>0.05) from the control group (28.2%). Total cell number was also greater in BCB+ (155.1 ± 36.2) than in BCB- (116.6 ± 40.5) and control (127.5 ± 35.7) blastocysts. Furthermore, the apoptotic cell number was less in BCB+ (3.7 ± 4.4) than in BCB- blastocysts (8.7 ± 8.7) but not different from the control group (5.9 ± 3.9). BCB+ embryos contained more mitochondria compared to BCB- embryos (P<0.05). There was no significant difference in intercellular lipid accumulation in embryos from all groups. Interferon-τ (IFNτ), transforming growth factor β1 (TGFB1) and secreted seminal-vesicle Ly-6 protein 1 (SSLP1) gene expression was greater in BCB+ than in BCB- blastocysts. By contrast, Bcl2-associated X protein (BAX) and heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) gene expression was greater in BCB- than in BCB+ and control embryos. In conclusion, oocyte-derived embryos selected on the basis of BCB staining showed differences in developmental rate, quality, mitochondrial content and target gene expression compared to control embryos.

Incidence of apoptosis and transcript abundance in bovine follicular cells is associated with the quality of the enclosed oocyte

The close contact and interaction between the oocyte and the follicular environment influence the establishment of oocyte developmental competence. Moreover, it is assumed that apoptosis in the follicular cells has a beneficial influence on the developmental competence of oocytes. The aim of this study was to investigate whether bovine oocytes with varied developmental competence show differences in the degree of apoptosis and gene expression pattern in their surrounding follicular cells (cumulus and granulosa cells). Oocytes and follicular cells from follicles of 3 to 5 mm in diameter were grouped as brilliant cresyl blue (BCB)+ and BCB- based on glucose-6-phosphate dehydrogenase (G6PDH) activity in the ooplasm by BCB staining. In the follicular cells initial, early and late apoptotic events were assessed by analyzing caspase-3 activity, annexin-V and TUNEL, respectively. Global gene expression was investigated in immature oocytes and corresponding follicular cells. BCB+ oocytes resulted in a higher blastocyst rate (19.3%) compared to the BCB- group (7.4%, P < 0.05). Moreover, the analysis of apoptosis showed a higher caspase-3 activity in the follicular cells and an increased degree of late apoptotic events in granulosa cells in the BCB+ compared with the BCB- group. Additionally, the global gene expression profile revealed a total of 34 and 37 differentially expressed genes between BCB+ and BCB- cumulus cells and granulosa cells, respectively, whereas 207 genes showed an altered transcript abundance between BCB+ and BCB- oocytes. Among these, EIF3F, RARRES2, RNF34, ACTA1, GSTA1, EIF3A, VIM and CS gene transcripts were most highly enriched in the BCB+ oocytes, whereas OLFM1, LINGO1, ALDH1A3, PTHLH, BTN3A3, MRPS2 and PPM1K were most significantly reduced in these cells. Therefore, the follicular cells enclosing developmentally competent oocytes show a higher level of apoptosis and a different pattern of gene expression compared to follicular cells enclosing non-competent bovine oocytes.

cDNA microarray analysis of gene expression in parthenotes and in vitro produced buffalo embryos

The retarded development of parthenote embryo could be due to aberrant epigenetic imprinting, which may disrupt many aspects and lead to conceptus demise. The present work was conducted to: 1) compare the development of in vitro produced (IVP) and parthenogenetically developed (P) buffalo embryos from the 2-cell to blastocyst stage; 2) investigate the global gene expression profile and search for new candidate transcripts differing between IVP and P buffalo blastocyst using cDNA microarray analysis (validated by Real Time PCR); 3) follow the particular expression patterns of PLAC8 and OCT4 genes at five different stages of preimplantation development by Real Time PCR; and 4) study the expression of CDX2 at the blastcocyst stage. Cleavage rate was higher (P < 0.05) in P than IVP buffalo embryos, while, progression to blastocyst and number of cells per blastocyst were lower (P < 0.05) in P than IVP blastocysts. Microarray analysis indicate that 56 differentially expressed genes between the two groups, of which 51 genes (91.07%) were up-regulated, and five genes were downregulated in IVP blastocyst, using 1.4 fold-changes as a cutoff. Differentially expressed genes are related to translation, nucleic acid synthesis, cell adhesion and placentation. Validation of candidate genes revealed that the transcript abundance of PTGS2, RPS27A, TM2D3, PPA1, AlOX15, RPLO and PLAC8 were downregulated (7/8) in parthenote blastocyst compared to the IVP blastocyst. PLAC8 gene expression was higher (P < 0.05) at 2-cell, morula and blastocyst stages in IVP embryos compared with parthenote embryos. The OCT4 gene expression was higher (P < 0.05) in 2-cell, 4-cell, 8-cell and blastocysts produced in vitro. In conclusion, the retarded development of parthenogenetic buffalo embryos could be due to downregulation of genes related to translation, nucleic acid synthesis, cell adhesion, and placental development. The low expression of PLAC8 and OCT4 during the different stages of development may be responsible, in part, to the failure of development of parthenote buffalo embryos.

Transcriptional response of the bovine endometrium and embryo to endometrial polymorphonuclear neutrophil infiltration as an indicator of subclinical inflammation of the uterine environment

The aim of the present study was to analyse the effect of subclinical endometritis on endometrial and embryonic gene expression. A total of 49 cows at either Day 0 or Day 7 of the oestrous cycle (62–83 days post partum) following superovulation were classified as having subclinical endometritis (SE-0, SE-7) or a healthy endometrium (HE-0, HE-7) on the basis of endometrial cytological evaluation. Endometrial samples and associated embryos were subjected to global transcriptome analysis using the Bovine GeneChip (Affymetrix, Santa Clara, CA, USA) and aberrant transcript profiles were observed in SE-0 and SE-7 cows. At Day 0, 10 transcripts were found to be differentially expressed in endometrial samples. Specifically, the PDZK1, PXDN, DDHD2, GPLD1 and SULT1B1 genes were downregulated, whereas the PKIB, LOC534256, BT29392, LYZ and S100A14 genes were upregulated in SE-0 cows. Similarly, 11 transcripts were found to be differentially regulated on Day 7. Of these, GNPTG, BOLA-DQA5, CHD2, LOC541226, VCAM1 and ARHGEF2 were found to be downregulated, whereas PSTPIP2, BT236441 and MGC166084 were upregulated in SE-7 cows. Accordingly, endometrial health status affected the number of flushed, transferable embryos. In all, 20 genes were differentially regulated in blastocysts derived from HE-7 and SE-7 cows. Of these, GZMK, TCEAL4, MYL7, ADD3 and THEM50B were upregulated, whereas NUDCD2, MYO1E, BZW1, EHD4 and GZMB were downregulated. In conclusion, endometrial polymorphonuclear neutrophil infiltration as an indicator of subclinical endometritis is associated with changes in endometrial gene expression patterns, including genes involved in cell adhesion and immune modulation. Consequently, subclinical endometritis affects gene expression in embryos, including the expression of genes related to membrane stability, the cell cycle and apoptosis.

G6PDH-activity in equine oocytes correlates with morphology, expression of candidate genes for viability, and preimplantative in vitro development

Efficiencies for in vitro production of equine embryos are still low due to highly variable developmental competences of equine immature oocytes. In contrast to the equine, in vitro developmental competence of immature oocytes has been predicted successfully by the activity of glucose-6-phosphate dehydrogenase (G6PDH) indicated by brilliant cresyl blue (BCB) dye in a range of different species. Therefore, the aim of the present study was to test the association between G6PDH activity in equine oocytes with: (1) cumulus morphology and oocyte properties in terms of diameter and volume; (2) maturational competence; (3) gene expression of certain molecular markers; and (4) in vitro embryo development after intracytoplasmic sperm injection. Equine oocytes were exposed to BCB stain and were classified as BCB+ or BCB- according to their ability to convert the dye from blue to colorless. Additionally, BCB+ and BCB- oocytes were subclassified as having a compact (Cp) or expanded (Ex) cumulus complex. As a result, BCB+ oocytes had a greater proportion of expanded cumulus oocyte complexes compared with BCB- oocytes (71.2% vs. 49.5%). Moreover, we observed a significant difference in oocyte diameter and volume between BCB+ and BCB- oocytes irrespective of cumulus morphology. BCB+ oocytes reached a higher maturation rate compared with BCB- oocytes (59.0% vs. 28.7%). Regarding the analyzed candidate genes, relative transcript abundance was significantly different for nine genes. The expression of eight genes was significantly higher (P < 0.05) for BCB+ oocytes, including ATPV6E, IF-3, TFAM, DNMT1, STAT3, Aurora-A, ODC1, and CKS2 whereas BCB- oocytes showed higher in expression of COX1. These results are in line with the observed developmental competence. Cleavage rate (45.9% vs. 29.0%) and percentage of embryos that reached the blastocyst stage (9.2% vs. 1.4%) were significantly higher for embryos derived from BCB+ oocytes compared with BCB- oocytes. In conclusion, the present study provides evidence that G6PDH-activity in immature equine oocytes is a useful predictor for subsequent in vitro developmental competence.

Bovine blastocysts with developmental competence to term share similar expression of developmentally important genes although derived from different culture environments

This study was conducted to investigate the gene expression profile of in vivo-derived bovine embryo biopsies based on pregnancy outcomes after transferring to recipients. For this, biopsies of 30-40% embryos were taken from grade I blastocysts (International Embryo Transfer Society Manual) and the remaining 60-70% of the intact embryos were transferred to recipients. Frozen biopsies were pooled into three distinct groups based on the pregnancy outcome after transferring the corresponding parts, namely those resulting in no pregnancy (NP), pregnancy loss (PL), and calf delivery (CD). Array analysis revealed a total of 41 and 43 genes to be differentially expressed between biopsies derived from blastocysts resulting in NP versus CD and PL versus CD respectively. Genes regulating placental development and embryo maternal interaction (PLAC8) were found to be upregulated in embryo biopsies that ended up with CD. Embryo biopsies that failed to induce pregnancy were enriched with mitochondrial transcripts (Fl405) and stress-related genes (HSPD1). Overall, gene expression profiles of blastocysts resulting in NP and CD shared similar expression profiles with respect to genes playing significant roles in preimplantation development of embryo. Finally, comparing the transcript signatures of in vivo- and in vitro-derived embryos with developmental competence to term revealed a similarity in the relative abundance of 18 genes. Therefore, we were able to present a genetic signature associated with term developmental competence independent of the environmental origin of the transferred blastocysts.

Suppression of the transcription factor MSX1 gene delays bovine preimplantation embryo development in vitro

This study was conducted to investigate the effect of suppressing transcription factor geneMSX1on the development ofin vitroproduced bovine oocytes and embryos, and identify its potential target genes regulated by this gene. Injection of long double-stranded RNA (LdsRNA) and small interfering RNA (siRNA) at germinal vesicle stage oocyte reducedMSX1mRNA expression by 73 and 37% respectively at metaphase II stage compared with non-injected controls. Similarly, injection of the same anti-sense oligomers at zygote stage reducedMSX1mRNA expression by 52 and 33% at 8-cell stage compared with non-injected controls. Protein expression was also reduced in LdsRNA- and siRNA-injected groups compared with non-injected controls at both stages. Blastocysts rates were 33, 28, 20 and 18% in non-injected control, scrambled RNA (scRNA), LdsRNA- and siRNA-injected groups respectively. Cleavage rates were also significantly reduced in Smartpool siRNA (SpsiRNA)-injected group (53.76%) compared with scRNA-injected group (57.76%) and non-injected control group (61%). Large-scale gene expression analysis showed that 135 genes were differentially regulated in SpsiRNA-injected group compared with non-injected controls, of which 54 and 81 were down- and up-regulated respectively due to suppression ofMSX1. Additionally, sequence homology mapping and gene enrichment analysis with known human pathway information identified several functional modules that were affected due to suppression ofMSX1. In conclusion, suppression ofMSX1affects oocyte maturation, embryo cleavage rate and the expression of several genes, suggesting its potential role in the development of bovine preimplantation embryos.

Bovine pretransfer endometrium and embryo transcriptome fingerprints as predictors of pregnancy success after embryo transfer

Aberrant gene expression in the uterine endometrium and embryo has been the major causes of pregnancy failure in cattle. However, selecting cows having adequate endometrial receptivity and embryos of better developmental competence based on the gene expression pattern has been a greater challenge. To investigate whether pretransfer endometrial and embryo gene expression pattern has a direct relation with upcoming pregnancy success, we performed a global endometrial and embryo transcriptome analysis using endometrial and embryo biopsy technology and the pregnancy outcome information. For this, endometrial samples were collected from Simmental heifers at day 7 and 14 of the estrous cycle, one cycle prior to embryo transfer. In the next cycle, blastocyst stage embryos were transferred to recipients at day 7 of the estrous cycle after taking 30-40% of the blastocyst as a biopsy for transcriptome analysis. The results revealed that at day 7 of the estrous cycle, the endometrial gene expression pattern of heifers whose pregnancy resulting in calf delivery was significantly different compared with those resulting in no pregnancy. These differences were accompanied by qualitative and quantitative alteration of major biological process and molecular pathways. However, the transcriptome difference was minimal between the two groups of animals at day 14 of the estrous cycle. Similarly, the transcriptome analysis between embryos biopsies that resulted in calf delivery and those resulted in no pregnancy revealed a total of 70 differentially expressed genes. Among these, the transcript levels of 32 genes including SPAG17, PF6, UBE2D3P, DFNB31, AMD1, DTNBP1, and ARL8B were higher in embryo biopsies resulting in calf delivery. Therefore, the present study highlights the potential of pretransfer endometrial and embryo gene expression patterns as predictors of pregnancy success in cattle.

248 DIESTRUS TRANSCRIPTOME DYNAMICS OF BOVINE ENDOMETRIUM IN RELATION TO PREGNANCY SUCCESS AFTER EMBRYO TRANSFER

This experiment aimed to investigate the diestrus transcriptome dynamics of endometrium that resulted in calf delivery or no pregnancy after embryo transfer. Endometrium biopsies were collected from Simmental cyclic heifers at Days 7 and 14 of estrus cycle. On the next cycle, in vivo-produced Day 7 blastocysts were transferred to all animals at Day 7 of estrous cycle. Following pregnancy diagnosis, the endometrial biopsies collected at Day 7 and 14 were categorized based on the pregnancy success. Those endometrial biopsies collected from heifers that subsequently delivered a calf were assigned to the calf-delivery group, and those collected from heifers that did not conceive were assigned to the no-pregnancy group. The endometrial temporal transcriptome profile was compared between Days 7 and 14 in both heifer groups. Total RNA was isolated from each sample in triplicate. Two rounds of RNA amplification were performed using MEGAscript® T7 Kit (Ambion, Inc., Austin, TX, USA) and GeneChip® IVT Labeling Kit (Affymetrix, Inc., Santa Clara, CA, USA), respectively. Following fragmentation, biotin-labeled cRNA samples were hybridized to Affymetrix bovine gene chip array. The microarray data normalization and background correction were performed using GCRMA, and the differentially expressed genes (DEG) (fold change >2,P < 0.05, FDR < 0.3) were identified using LIMMA written on R package integrated with Bioconductor. The result showed that in the calf-delivery group, there were 1867 DEG, among which 1015 and 852 were up- and down-regulated, respectively, in Day 7 compared with Day 14 of the estrous cycle. Some of those genes are believed to be involved in reproductive system development and function (F3, PTGER2, PTGER4, MFGE8, PTGS2, and TDGF1), embryonic development (ALDH1A1,ALDH1A3, FGF2, TGFBR2, PDGFB, and TGFBR2), and nervous system development and function (CYP3A4, CYP3A4, HSD17B4, FOXA2, MET, TDGF, WNT11). The bioinformatic analysis using KEGG revealed that those DEG were classified into several pathways including the MAPK signaling pathway. On the other hand, in the no-pregnancy group, 254 genes were found to be differentially expressed, of which 160 and 94 were up- and down-regulated, respectively, in Day 7 compared with Day 14 of the estrous cycle. Some of these genes were found to be involved in signal transducer activity (AXIN2, AGTR1, MAPK10, NTRK2, TLR2, DMBT1, IL1RN, CDK5, CHRNE), transferase activity (DGKI, TXNDC6, RPS6KA5, RIOK3, MYLK, CDK5, MET, NTRK2), receptor activity (MET,AGTR1, NTRK2, TLR2, DMBT1, CHRNE), regulation of transcription (FOS, ELF1, BHLHB2,ATF3, HOXA11), signal transduction (TLR2, AGTR1, FCNB, DGK, NOTCH2, ADAM9, PLEK), and transcription regulator activity (BHLHB2, FOS, ELF1,ATF3, HOXA11). Those DEG were found to be involved in different pathways including the focal adhesion pathway. In conclusion, the result of the current study revealed a remarkable transcriptome dynamics between Days 7 and 14 of the estrous cycle in cows resulted in calf delivery compared with those that did not support pregnancy.

357 MOLECULAR AND SUBCELLULAR CHARACTERIZATION OF BOVINE OOCYTES AND THEIR SURROUNDING FOLLICULAR CELLS IN SUBJECT TO THEIR DEVELOPMENTAL COMPETENCE

Though many factors have been shown to affect the oocyte developmental potential, it remains difficult to draw clear and reliable criteria for oocyte selection. With the urgent need for establishing non-invasive means for oocyte selection, the brilliant cresyl blue (BCB) staining test based on glucose- 6-phosphate dehydrogenase (G6PDH) activity has been successfully used to differentiate competent and non-competent bovine oocytes (Alm et al. 2005 Theriogenology 63, 2194-2205). Also it has been hypothesized that there is a correlation between the appearance of light atretic granulosa cells (GC) in the follicle and an increased developmental competence of the oocyte. Here we aim to investigate whether different developmental competent oocytes show differences concerning the degree of apoptosis or in the gene expression pattern of their follicular environment [GC and cumulus cells (CC)]. After follicular aspiration, the immature COCs were separately stained with 26 μM BCB for 90 minutes. Based on their colouration, oocytes were grouped into BCB- (colourless cytoplasm, low developmental competence) and BCB+ (coloured cytoplasm, high developmental competence). The corresponding CC and GC were also grouped according to the colouration of the enclosed oocytes. BCB+ oocytes were found to result in a higher blastocyst rate at Day 8 of in vitro culture (34.1%) compared to BCB- ones (3.9%) (n = 601 COCs). Apoptosis in GC was determined either by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) or by Annexin-V-staining followed by flow cytometric measurement. The degree of apoptosis in GC of BCB+ oocytes was slightly increased in contrast to the BCB- group (17.0 v. 11.0%; P < 0.05). The abundance and activity of protein kinases Akt, MAP kinase, and Caspase-3 were estimated by western blot analysis. CC, GC, and oocytes from the BCB+ group showed a higher ratio of cleaved Caspase-3/Caspase-3 in contrast to all compartments of the BCB- group (P < 0.05). Moreover, a bovine Affymetrix microarray plate form (Affymetrix Inc., Santa Clara, CA, USA) was used to analyze the gene expression profiles in oocytes, CC, and GC. The BCB+ oocytes were found to be enriched with genes regulating the oocyte maturation (EIF3F, PRKCSH) and the transition from maternal to embryonic genome activation (HMG2L1). Also BCB+ derived follicular compartments showed elevated expression of genes related to steroidgenesis, cumulus expansion and gonadotropins. In conclusion, the results demonstrate that the developmental competence of oocytes is associated with the apoptotic level and altered expression of genes in cells of their follicular environment. This work was supported financially by Deutsche Forschungsgemeinschaft (To 138/5-1).

240 DIFFERENCES IN GLOBAL TRANSCRIPTOME PROFILE OF BOVINE BLASTOCYSTS DERIVED FROM SUPEROVULATED OR SYNCHRONIZED CYCLIC HEIFERS

Estrus synchronization and superovulation are the most widely used procedures in embryo transfer technology. However, changes in the oviduct and uterine environment due to these procedures and the subsequent influence on embryos have not yet been investigated. This study was con- ducted to investigate the effect of oviduct environment of only synchronized or superovulated cyclic heifers on the gene expression profile of blastocysts. Bovine Affymetrix array analysis was performed using 2 groups of blastocysts. The first group was bovine blastocysts produced after superovulation of Simmental heifers (n = 9) using 8 consecutive FSH injections over 4 days in decreasing doses (in total, 300-400 mg of FSH equivalent according to body weight) and flushed at Day 7 by nonsurgical endoscopic method. The second group was bovine blastocysts derived from synchronized Simmental heifers (n = 4) after transfer of 2-cell stage embryos from superovulated donor Simmental heifers (n = 9) by nonsurgical transvaginal endoscopy tubal transfer method. Total RNA was extracted from 3 pools of embryos from each experimental group (6 embryos per pool). A total of 6 biotin-labeled cRNA samples were hybridized on 6 bovine Affymetrix arrays. Data analysis was performed using LIMMA written on R package, which maintained the Bioconductor. Array data analysis revealed a total of 454 transcripts to be differen- tially expressed (P < 0.05, fold change >2) between the 2 groups. Of these, 429 and 25 were up- and down-regulated, respectively, in blastocysts derived from superovulated heifers compared with those derived from synchronized animals. Genes involved in response to stress (HSPA14 and HSPE1), cellular and metabolic processes (CPSF3, ATPIF1, POMP, and MDH2), translation (RPS17, EEF1B2, and EIF4E), and cell commu- nication (FN1, KRT18, and DSG2) were found to be enriched in blastocysts derived from superovulated animals. On the other hand, protein metabolic processes related genes (CLGN) were found to be enriched in blastocysts derived from the synchronized group. The KEGG analysis of the differentially expressed genes showed that the ribosome and oxidative phosphorylation pathways are the dominant pathways and genes involved in these pathways are greatly abundant in the blastocysts derived from superovulated animals. Quantitative real-time PCR has confirmed the transcript abundance of 7 out of 8 genes selected for validation. In conclusion, blastocysts cultured in synchronized animals post 2-cell stage showed significant differences in transcriptome profile compared with their counterparts that remained in superovulated heifers until Day 7. Further functional analysis of some selected candidate genes could give new insights into mechanisms regulating the ability of embryos to survive after transfer.

Identification and characterization of miRNAs expressed in the bovine ovary

Background

MicroRNAs are the major class of gene-regulating molecules playing diverse roles through sequence complementarity to target mRNAs at post-transcriptional level. Tightly regulated expression and interaction of a multitude of genes for ovarian folliculogenesis could be regulated by these miRNAs. Identification of them is the first step towards understanding miRNA-guided gene regulation in different biological functions. Despite increasing efforts in miRNAs identification across various species and diverse tissue types, little is known about bovine ovarian miRNAs. Here, we report the identification and characterization of miRNAs expressed in the bovine ovary through cloning, expression analysis and target prediction.

Results

The miRNA library (5'-independent ligation cloning method), which was constructed from bovine ovary in this study, revealed cloning of 50 known and 24 novel miRNAs. Among all identified miRNAs, 38 were found to be new for bovine and were derived from 43 distinct loci showing characteristic secondary structure. While 22 miRNAs precursor loci were found to be well conserved in more than one species, 16 were found to be bovine specific. Most of the miRNAs were cloned multiple times, in which let-7a, let-7b, let-7c, miR-21, miR-23b, miR-24, miR-27a, miR-126 and miR-143 were cloned 10, 28, 13, 4, 11, 7, 6, 4 and 11 times, respectively. Expression analysis of all new and some annotated miRNAs in different intra-ovarian structures and in other multiple tissues showed that some were present ubiquitously while others were differentially expressed among different tissue types. Bta-miR-29a was localized in the follicular cells at different developmental stages in the cyclic ovary. Bio-informatics prediction, screening and Gene Ontology analysis of miRNAs targets identified several biological processes and pathways underlying the ovarian function.

Conclusion

Results of this study suggest the presence of miRNAs in the bovine ovary, thereby elucidate their potential role in regulating diverse molecular and physiological pathways underlying the ovarian functionality. This information will give insights into bovine ovarian miRNAs, which can be further characterized for their role in follicular development and female fertility as well.

Gene expression profile of cumulus cells derived from cumulus-oocyte complexes matured either in vivo or in vitro

Although it is well established that maturation conditions have a clear influence on oocyte developmental competence, it is not known whether this could be due to downstream effects of perturbation of the transcript profile of the oocyte's adjacent cumulus cells. Therefore, the aim of the present study was to compare the transcript profiles of cumulus cells derived from cumulus-oocyte complexes (COCs) matured in vitro or in vivo. Using a previously validated combined synchronisation and superstimulation protocol, COCs were recovered from beef heifer ovaries just before the expected time of the LH surge and matured in vitro, while in vivo-matured COCs were recovered just before ovulation (20 h after the LH surge). A custom-made cDNA microarray containing 2278 granulosa/cumulus transcripts was used for target and dye-swap hybridisations. In all, 64 genes were differentially expressed between the two groups. Transcript abundance of key genes associated with cumulus expansion (TNFAIP6) and regulation of oocyte maturation (INHBA and FST) were upregulated in in vivo-derived cumulus cells. However, cumulus cells derived from IVM COCs were enriched with genes involved in response to stress (HSPA5 and HSP90AB1). Quantitative real-time polymerase chain reaction confirmed the array results for eight of 10 genes selected for validation. The data presented here reveal that differences in oocyte developmental capacity after maturation in vitro or in vivo are accompanied by distinct differences in transcript abundance of the surrounding cumulus cells.

183 EFFECT OF WELL IN WELL CULTURE OF BOVINE EMBRYOS ON GENE EXPRESSION PROFILE

To culture embryos in small groups, the well in well culture system (miniwells harboring 1 single embryo within the well) has been developed previously. In this work, we aimed to examine the effects of the microenvironment provided by well in well culture and embryo density on the relative abundance of transcripts in the resulting embryos. Cumulus–oocyte complexes (COCs) were aspirated from small follicles (2 to 8 mm), and COCs were cultured in 400 μL of modified TCM (TCM-199, Sigma, Taufkirchen, Germany) supplemented with 12% heat-inactivated estrous cow serum and 10 μg mL–1 of FSH (FSH-p, Sheering, Kenilworth, NJ, USA) for 24 h at 39°C in a humidified atmosphere with 5% CO2 in air. Fertilization was performed in Fert-TALP supplemented with 1 μg mL–1 of heparin. Zygotes were allocated randomly in 2 groups, namely: well in well culture (16 miniwells of 0.7 diameter and deepness each containing 1 embryo per well) and group of 16 (group culture of 16 embryos per well). Six pools each containing 20 Day 7 blastocysts derived from the first 2 groups were used to investigate large-scale gene expression analysis using BlueChip cDNA-Array. Three pools each containing 5 blastocysts were used for Array data validation by real-time PCR using primers specific to 5 selected genes (ATP5, PLAC8, KRT8, S100A10, and ZP3). During validation in vivo-derived bovine blastocysts were included to be used as standard. Significance Analysis of Microarray identified 75 transcripts differentially expressed between the 2 groups. Blastocysts derived from well in well culture were found to be enriched with genes regulating different molecular functions including structural constituent of ribosome (RPS29), protein binding (Cul1), calcium ion binding (S100A10, NPTX2), nitric oxide synthase regulator activity (HSPCA), and RNA polymerase II transcription factor activity (UHRF1). However, blastocysts derived from group of 16 culture were found to be enriched with genes involved in oxidoreductase activity (ALOX15, AKR1B), cytochrome-c oxidase activity (COX7A2), hydrogen ion transporting ATP synthase activity (ATP5O), transcription (PTTG1), and cell redox homeostasis (TXN). According to their biological process, genes enriched in blastocysts derived from well in well culture belong to small molecule transport and signal transduction, whereas most downregulated genes have a metabolic function. Comparison of the transcript abundance of the 5 selected genes in the 3 embryo groups showed that the expression of ATP5, PLAC8, and KRT8 in embryos from well in well culture resembles to the relative abundance in blastocyst derived from in vivo culture. However, with respect to the expression of S100A10 and ZP3 genes, blastocysts derived from group culture showed similarity with embryos derived from in vivo. In conclusion, microenvironment affects the gene expression pattern of the resulting embryos.

196 EMBRYO BIOPSY TRANSCRIPTOMICS: A POTENTIAL TOOL TO IDENTIFY TRANSCRIPTS DIRECTLY RELATED TO THE ABILITY OF THE EMBRYO TO INDUCE PREGNANCY AFTER TRANSFER

The incidence of pregnancy loss due to embryonic mortality in cattle is one of the major causes of reproductive failure. The early embryonic loss can be due to problems with the embryo itself, the uterine environment, or interactions between the embryo and the uterus. So, this study was conducted to investigate the gene expression profile of bovine embryo biopsies produced in vivo and in vitro that resulted in different pregnancy outcomes. For this, biopsies representing 30 to 40% of the intact in vitro and in vivo blastocysts were taken, and 60 to 70% part was allowed to re-expand prior to transfer to recipients. Based on the pregnancy outcome after transfer, biopsies (n = 10 per pool) were grouped into 3 distinct phenotypes: those that resulted in no pregnancy, those that resulted in resorption, and those that resulted in successful pregnancy and subsequent calf delivery. A bovine cDNA microarray with 2000 clones was used to analyze the gene expression profiles of 3 replicates from each embryo biopsy group. Array data analysis revealed a total of 50 and 52 genes to be differentially expressed between biopsies derived from in vivo blastocysts that resulted in no pregnancy v. calf delivery and resorption v. calf delivery, respectively. Similarly, a total of 52 and 58 transcripts were differentially expressed between biopsies derived from in vitro-produced blastocysts that resulted in no pregnancy v. calf delivery and resorption v. calf delivery, respectively. Quantitative real-time PCR has confirmed the expression profile of 6 selected candidate genes. A distinct set of genes were found to be commonly expressed between in vitro- and in vivo-derived blastocyst biopsies, which ended up with the same pregnancy outcome. Biopsies, which ended up with calf delivery, were found to be enriched with transcripts involved in nucleosome assembly (KRT8), translation (RPLPO), electron transport (COX-2), and placenta specific (PLAC8). On the other hand, transcripts regulating immune response (TNFa), response to stress (HSPD1), and cell adhesion (CD9) were up-regulated in embryos that resulted in no pregnancy or resorption. Differences in transcript abundance of some genes have been seen between biopsies derived from in vitro and in vivo blastocysts. Biopsies from in vivo-derived blastocysts and that ended up with resorption were found to be enriched with transcripts regulating calcium-binding protein (S100A10, S100A14). Transcription factor-related transcripts (CDX2, HOXB7) were up-regulated in vitro-derived blastocyst biopsies that resulted in no pregnancy. In conclusion, the results evidenced that embryos derived from either in vitro or in vivo have more similarities than differences in their transcript abundance with respect to the ability in initiating pregnancy.

195 TRANSCRIPTOME PROFILING OF BOVINE ENDOMETRIUM BASED ON THE PREGNANCY OUTCOME AFTER TRANSFER OF IN VIVO-DERIVED EMBRYOS

Transcriptome profiling of pre-transfer cycle endometrium in relation to its ability to sustain the upcoming pregnancy may pave the way to develop or identify molecular markers that can be utilized to detect and select receptive endometrium before embryo transfer. Here, we aim to show differential expression of genes between endometrium biopsies derived from recipients during pre-transfer cycle based on the pregnancy successes after embryo transfer. For this, endometrium biopsies were taken from 56 Simmental cyclic heifers of the same age at day 7 and 14 of the estrous cycle. On the next cycle, in vivo-produced day 7 blastocysts were transferred to all animals at day 7 of the estrous cycle. Pregnancy diagnosis was done at 28, 42, and 56 days of gestation. Thirty-two cows were returned to heat after 21 days, 7 were pregnant until day 42 but no pregnancy after that, and 15 resulted in calf delivery. Subsequently, the endometrium biopsies sampled during the pre-transfer period were categorized based on the pregnancy outcome. Those endometrial biopsies taken at days 7 and 14 during the pre-transferred period from those that resulted in successful calf delivery were named as d7CD and d14CD, respectively, and those endometrial samples collected at days 7 and 14 during pre-transferred period from those groups that resulted in no pregnancy were named as d7NP and d14NP, respectively. Total RNA was extracted from 3 pools of each experimental group in 3 replicates using RNeasy mini kit (Qiagen, Hilden, Germany). A total of 12 biotin-labeled cRNA samples were hybridized on 12 bovine Affymetrix arrays (Affymetrix, Santa Clara, CA, USA) consisting of 24128 probe sets. The microarray data normalization and background correction was performed using guanine cytosine robust multi-array analysis, and the data analysis was performed using LIMMA written on R package, which maintained the bioconductor. The results showed that 1130 transcripts were differentially expressed between d7CD and d7NP, of which 626 and 504 were up- and down-regulated, respectively, in d7CD. Genes that involve in regulation of transcription (PPARA, NR2F1, MYB, MYB, and CHF2) and the collagen families (COL1A1 and COL1A2) were enriched in d7CD. A total of 234 transcripts were differentially expressed between d14CD and d14NP, of which 94 and 140 were up- and down-regulated, respectively, in d14CD compared to d14NP. Transcripts involved in protein amino acid phosphorylation (MA2K6, GATM, AK3L1, and MAPK10) were found to be enriched in d14CD compared to d14NP. In conclusion, pre-transfer endometrium biopsies showed significant differences in transcriptome profile depending on the pregnancy outcome after transfer of in vivo-derived blastocysts and enable to identify transcripts related to pregnancy establishment.

Effect of the microenvironment and embryo density on developmental characteristics and gene expression profile of bovine preimplantative embryos cultured in vitro

The Well of the Well (WOW) system has been developed to culture embryos in small groups or to track the development of single embryos. In the present study, we aimed to examine the effects of the microenvironment provided by the WOW system and embryo density on developmental rates, embryo quality and preimplantative gene expression profile of the resulting embryos. Embryos cultured in a group of 16 reached the blastocyst stage at a significantly lower level than zygotes cultured in a group of 50 (22.2 vs 30.3%), whereas zygotes cultured in WOW were able to compensate against low embryo densities, reaching a blastocyst rate as high as embryos cultured in a group of 50 (31.3 vs 30.3%). Moreover, embryos derived from WOW culture did not differ in terms of differential cell counts and apoptotic cell index compared with controls. The gene expression analysis revealed 62 transcripts to be upregulated and 33 transcripts to be downregulated by WOW culture. Comparing the in vivo derived blastocysts with the blastocysts derived from WOW culture, and group culture, expression of ATP5A1, PLAC8 and KRT8 was more similar to the embryos derived from WOW culture, whereas expression of S100A10 and ZP3 genes was more similar to blastocysts cultured in a group. In conclusion, microenvironment as well as embryo density significantly affected developmental rates. While subsequent blastocysts did not differ in terms of differential cell counts and apoptotic cell index, significant differences were observed in terms of the relative abundance of transcripts in the resulting embryos.

Molecular and subcellular characterisation of oocytes screened for their developmental competence based on glucose-6-phosphate dehydrogenase activity

Oocyte selection based on glucose-6-phosphate dehydrogenase (G6PDH) activity has been successfully used to differentiate between competent and incompetent bovine oocytes. However, the intrinsic molecular and subcellular characteristics of these oocytes have not yet been investigated. Here, we aim to identify molecular and functional markers associated with oocyte developmental potential when selected based on G6PDH activity. Immature compact cumulus-oocyte complexes were stained with brilliant cresyl blue (BCB) for 90 min. Based on their colouration, oocytes were divided into BCB(-) (colourless cytoplasm, high G6PDH activity) and BCB(+) (coloured cytoplasm, low G6PDH activity). The chromatin configuration of the nucleus and the mitochondrial activity of oocytes were determined by fluorescence labelling and photometric measurement. The abundance and phosphorylation pattern of protein kinases Akt and MAP were estimated by Western blot analysis. A bovine cDNA microarray was used to analyse the gene expression profiles of BCB(+) and BCB(-) oocytes. Consequently, marked differences were found in blastocyst rate at day 8 between BCB(+) (33.1+/-3.1%) and BCB(-) (12.1+/-1.5%) oocytes. Moreover, BCB(+) oocytes were found to show higher phosphorylation levels of Akt and MAP kinases and are enriched with genes regulating transcription (SMARCA5), cell cycle (nuclear autoantigenic sperm protein, NASP) and protein biosynthesis (RPS274A and mRNA for elongation factor 1alpha, EF1A). BCB(-) oocytes, which revealed higher mitochondrial activity and still nucleoli in their germinal vesicles, were enriched with genes involved in ATP synthesis (ATP5A1), mitochondrial electron transport (FL405), calcium ion binding (S100A10) and growth factor activity (bone morphogenetic protein 15, BMP15). This study has evidenced molecular and subcellular organisational differences of oocytes with different G6PDH activity.

254 MOLECULAR AND SUBCELLULAR CHARACTERIZATION OF OOCYTES SCREENED FOR THEIR DEVELOPMENTAL COMPETENCE BASED ON G6PDH ACTIVITY

Oocyte selection based on glucose-6-phosphate dehydrogenase (G6PDH) activity has been successfully used to differentiate between competent and incompetent bovine oocytes (Alm 2005 Theriogenology 63, 2194–2205). However, the intrinsic molecular and subcellular characteristics of these oocytes have not yet been investigated. Here we aim to compare the developmental, molecular, and subcellular characteristics of oocytes selected using brilliant cresyl blue (BCB) staining based on G6PDH activity. Immature compact cumulus–oocyte complexes (COCs) were stained with 26 µm BCB (B-5388, Sigma-Alderich, Taufenkirchen, Germany) for 90 min. Based on their coloration, oocytes were divided into BCB– (colorless cytoplasm, high G6PDH activity) and BCB+ (colored cytoplasm, low G6PDH activity). The chromatin configuration and the mitochondrial activity of oocytes were determined by fluorescence labelling and photometric measurement (n = 337). The abundance and phosphorylation pattern of protein kinases Akt and MAP kinase were estimated by western blot analysis (n = 500). A bovine cDNA microarray with 2000 clones was used to analyze the gene expression profiles of BCB+ and BCB– oocytes (n = 580). BCB+ oocytes were found to result in a higher blastocyst rate (33.1 � 3.1%) until Day 8 of in vitro culture compared to BCB– ones (12.1 � 1.5%). Moreover, BCB+ oocytes showed higher phosphorylation levels of Akt and MAP kinase compared to the BCB– oocytes. After array data analysis, BCB+ oocytes were found to be enriched with genes regulating transcription (SMARCA5), cell cycle (NASP), and protein biosynthesis (RPS274A and EEF1A1), while the BCB– oocytes had a higher level of genes involved in ATP synthesis (ATP5A1), mitochondrial electron transport (FL405), calcium ion binding (S100A10), and growth factor activity (BMP-15). Independent real-time quantitative PCR validated 90% (9/10) of the genes investigated to be in agreement with the array expression profile. The study has shown evidence of differences in molecular and subcellular organization of oocytes with different G6PDH activity.

Classification of graft hypertrophy after autologous chondrocyte implantation of full-thickness chondral defects in the knee

OBJECTIVE

Graft hypertrophy is a major complication seen in autologous chondrocyte implantation (ACI) with a periosteal flap. We present the first magnetic resonance imaging (MRI) classification for periosteal hypertrophy including a grading of clinical symptoms and the surgical consequences.

METHODS

One hundred and two patients with isolated chondral defects underwent an ACI covered with periosteum and were evaluated preoperatively, 6, 18 and 36 months after surgery. Exclusion criteria were meniscal pathologies, axial malpositioning and ligament instabilities. Baseline clinical scores were compared with follow-up data by paired Wilcoxon-tests for the modified Cincinnati knee, the ICRS (International Cartilage Repair Society) and a new MRI score including the parameters defect filling, subchondral edema, effusion, cartilage signal and graft hypertrophy. Hypertrophic changes were graded from 1 (minimal) to 4 (severe).

RESULTS

All scores showed significant improvement (P<0.001) over the entire study period. Patients with femoral lesions had significantly better results than patients with patella lesions after 18 and 36 months postoperative (P<0.03). Periosteal hypertrophy occurred in 28% of all patients. Fifty percent of all patella implants developed hypertrophic changes. No patient with grade 1, and all patients with grade 4 hypertrophy had to undergo revision surgery. The Pearson correlation between graft hypertrophy and ICRS score was 0.78 after 6 months, and 0.69 after 36 months (P<0.01). Inclusion of graft hypertrophy in the MRI score improves the correlation to clinical scores from 0.6 to 0.69.

CONCLUSIONS

Grading graft hypertrophy helps to identify patients needing an early shaving of the graft. Its integration into an MRI score improves correlation with clinical scores. Re-operation depends on the grade of hypertrophy and clinical symptoms.

Alterations in transcript abundance of bovine oocytes recovered at growth and dominance phases of the first follicular wave

Background

Oocyte developmental competence is highly affected by the phase of ovarian follicular wave. Previous studies have shown that oocytes from subordinate follicles recovered at growth phase (day 3 after estrus) are developmentally more competent than those recovered at dominance phase (day 7 after estrus). However, the molecular mechanisms associated with these differences are not well elucidated. Therefore, the objective of this study was to investigate transcript abundance of bovine oocytes retrieved from small follicles at growth and dominance phases of the first follicular wave and to identify candidate genes related to oocyte developmental competence using cDNA microarray.

Results

Comparative gene expression analysis of oocytes from growth and dominance phases and subsequent data analysis using Significant Analysis of Microarray (SAM) revealed a total of 51 differentially regulated genes, including 36 with known function, 6 with unknown function and 9 novel transcripts. Real-time PCR has validated 10 transcripts revealed by microarray analysis and quantified 5 genes in cumulus cells derived from oocytes of both phases. The expression profile of 8 (80%) transcripts (ANAXA2, FL396, S100A10, RPL24, PP, PTTG1, MSX1 and BMP15) was in agreement with microarray data. Transcript abundance of five candidate genes in relation to oocyte developmental competence was validated using Brilliant Cresyl Blue (BCB) staining as an independent model. Furthermore, localization of mRNA and protein product of the candidate gene MSX1 in sections of ovarian follicles at days 0, 1, 3 and 7 of estrous cycle showed a clear fluorescent signal in both oocytes and cumulus cells with higher intensity in the former. Moreover, the protein product was detected in bovine oocytes and early cleavage embryos after fertilization with higher intensity around the nucleus.

Conclusion

This study has identified distinct sets of differentially regulated transcripts between bovine oocytes recovered from small follicles at growth and dominance phases of the first follicular wave. The validation with independent model supports our notion that many of the transcripts identified here may represent candidate genes associated with oocyte developmental competence. Further specific functional analysis will provide insights into the exact role of these transcripts in oocyte competence and early embryonic development.