Project description:In vitro production (IVP) has been shown to affect embryonic gene expression and often result in large offspring syndrome (LOS) in cattle and sheep. To dissect the effects of in vitro maturation, fertilization and culture, we compared the expression profiles of single bovine blastocysts generated by: 1) in vitro maturation, fertilization and culture (IVF); 2) in vivo maturation, fertilization and in vitro culture (IVD); and 3) in vivo maturation, fertilization and development (AI). To conduct expression profiling, total RNA was isolated from individual embryos, linearly amplified and hybridized to a custom bovine cDNA microarray containing approximately 6,300 unique genes. There were 306, 367 and 200 genes differentially expressed between the AI and IVD, IVF and IVD and AI and IVF comparisons, respectively. Interestingly, 44 differentially expressed genes were identified between the AI embryos and both the IVF and IVD embryos, making these potential candidates for LOS. There were 60 genes differentially expressed between the IVF embryos and the AI and IVD embryos. The Gene Ontology category “RNA processing” was over-represented among the genes that were down-regulated in the IVF embryos, indicating an effect of in vitro oocyte maturation/fertilization on embryonic gene expression. A culture effect on the expression of genes involved in translation was also observed by the comparison of AI to IVD embryos. Keywords: developmental condition
Project description:In vitro production (IVP) has been shown to affect embryonic gene expression and often result in large offspring syndrome (LOS) in cattle and sheep. To dissect the effects of in vitro maturation, fertilization and culture, we compared the expression profiles of single bovine blastocysts generated by: 1) in vitro maturation, fertilization and culture (IVF); 2) in vivo maturation, fertilization and in vitro culture (IVD); and 3) in vivo maturation, fertilization and development (AI). To conduct expression profiling, total RNA was isolated from individual embryos, linearly amplified and hybridized to a custom bovine cDNA microarray containing approximately 6,300 unique genes. There were 306, 367 and 200 genes differentially expressed between the AI and IVD, IVF and IVD and AI and IVF comparisons, respectively. Interestingly, 44 differentially expressed genes were identified between the AI embryos and both the IVF and IVD embryos, making these potential candidates for LOS. There were 60 genes differentially expressed between the IVF embryos and the AI and IVD embryos. The Gene Ontology category M-bM-^@M-^\RNA processingM-bM-^@M-^] was over-represented among the genes that were down-regulated in the IVF embryos, indicating an effect of in vitro oocyte maturation/fertilization on embryonic gene expression. A culture effect on the expression of genes involved in translation was also observed by the comparison of AI to IVD embryos. Reference design with dye swap. 43 individual embryos were analyzed.
Project description:In vitro maturation (IVM) of the oocytes is a routine method in bovine embryo production. The competence of bovine oocytes to develop into embryo after IVM and in vitro fertilization (IVF) is lower as compared to in vivo preovulatory oocytes. Cumulus cells (CC) that enclose an oocyte are involved in the acquisition of oocyte quality during maturation. Using transcriptomic approach we compared cumulus cells gene expression during IVM with that in vivo preovulatory period.
Project description:In vitro maturation (IVM) of the oocytes is a routine method in bovine embryo production. The competence of bovine oocytes to develop into embryo after IVM and in vitro fertilization (IVF) is lower as compared to in vivo preovulatory oocytes. Cumulus cells (CC) that enclose an oocyte are involved in the acquisition of oocyte quality during maturation. Using transcriptomic approach we compared cumulus cells gene expression during IVM with that in vivo preovulatory period. Global transcriptional profiling was performed using cumulus cells collected from mature bovine oocytes (metaphase-II stage) after maturation performed either in vivo or in vitro. In vivo matured cumulus cells were collected from ovulatory follicles of Montbeliard adult cows by ovum pick-up in vivo (OPU, n=4). In vitro matured cumulus cells were recovered from the oocytes after 22h of in vitro culture of cumulus-oocyte complexes (50 COC per experiment) from 2-6 mm ovarian follicles of adult cows (MIV, n=4). Gene expression analysis was carried out between in vivo and in vitro matured cumulus representing a total of 8 slides (dye swap protocol)
Project description:The Toll-like receptor (TLR) and peptidoglycan recognition protein 1 (PGLYRP1) genes play key roles in the innate immune systems of mammals. While the TLRs recognize a variety of invading pathogens and induce innate immune responses, PGLYRP1 is directly microbicidal. We used custom allele-specific assays to genotype and validate 220 diallelic variants, including 54 nonsynonymous SNPs in 11 bovine innate immune genes (TLR1-TLR10, PGLYRP1) for 37 cattle breeds. Bayesian haplotype reconstructions and median joining networks revealed haplotype sharing between Bos taurus taurus and Bos taurus indicus breeds at every locus, and we were unable to differentiate between the specialized B. t. taurus beef and dairy breeds, despite an average polymorphism density of one locus per 219 bp. Ninety-nine tagSNPs and one tag insertion-deletion polymorphism were sufficient to predict 100% of the variation at all 11 innate immune loci in both subspecies and their hybrids, whereas 58 tagSNPs captured 100% of the variation at 172 loci in B. t. taurus. PolyPhen and SIFT analyses of nonsynonymous SNPs encoding amino acid replacements indicated that the majority of these substitutions were benign, but up to 31% were expected to potentially impact protein function. Several diversity-based tests provided support for strong purifying selection acting on TLR10 in B. t. taurus cattle. These results will broadly impact efforts related to bovine translational genomics.