Project description:we constructed a methylated DNA immunoprecipitation combined with high throughput sequencing (MeDIP-seq) strategy to investigate the differentially methylated genes between the Dorset, HanBB and Han++ sheep ovaries. Our findings suggest the genes involved in immune response, branched-chain amino acid metabolism, cell growth and cell junction were differentially methylated in or around the gene body regions. These findings provide prospective insights on the epigenetic basis of sheep fecundity.
Project description:Examination the DNA methylation statues of the main subpopulation of Chinese Mongolian sheep. A high quality methylome of Chinese Mongolian sheep was obtained, and established a list of DMRs potentially association with sheep body size
Project description:We performed a genome-wide analysis of mRNAs and lncRNAs from Small Tail Han sheep of genotypes FecBBFecBB (Han BB) and FecB+ FecB+ (Han++) and from Dorset sheep (Dorset) to identify potential regulators of fecundity. An integrated analysis revealed significantly correlated patterns of expression. Dramatic changes of mRNAs and lncRNAs suggest their critical roles in sheep fecundity. This study provides a novel view of the regulatory mechanisms involved in sheep fecundity.
Project description:The early stages of mammalian embryonic development involve the participation and cooperation of numerous complex processes, including nutritional, genetic, and epigenetic mechanisms. However, in embryos cultured in vitro, a developmental block occurs that affects embryo development and the efficiency of culture. Although the block period is reported to involve the transcriptional repression of maternal genes and transcriptional activation of zygotic genes, how epigenetic factors regulate developmental block is still unclear. In this study, we systematically analyzed whole-genome methylation levels during five stages of sheep oocyte and preimplantation embryo development using SC-WGBS technology. Then, we examined several million CpG sites in individual cells at each evaluated developmental stage to identify the methylation changes that take place during the development of sheep preimplantation embryos. Our results showed that two strong waves of methylation changes occurred, namely, demethylation at the 8- to 16-cell stage and methylation at the 16- to 32-cell stage. Analysis of DNA methylation patterns in different functional regions revealed a stable hypermethylation status in 3'UTRs and gene bodies; however, significant differences were observed in intergenic and promoter regions at different developmental stages. Changes in methylation at different stages of preimplantation embryo development were also compared to investigate the molecular mechanisms involved in sheep embryo development at the methylation level. In conclusion, we report a detailed analysis of the DNA methylation dynamics during the development of sheep preimplantation embryos. Our results provide an explanation for the complex regulatory mechanisms underlying the embryo developmental block based on changes in DNA methylation levels.
Project description:In this study, we selected differentially expressed miRNAs through construcing and analyzing the miRNA expression profile during 2-, 6-, and 12- month-old Small Tail Han Sheep ovaries, which provided a theoretical basis for the study of miRNAs regulating the reproduction of Small Tail Han Sheep. RNASeq techniques were used to perform profile analysis for these ovaries. The results showed that 11, 13 and 19 DE miRNAs were identified in 2- vs 6-, 6- vs 12-, and 2- vs 12-month-old ovaries, respectively. In total, 54, 37, and 198 predicted target genes of DE miRNAs were obtained from these three groups, respectively. GO and KEGG analyses showed that, in 2- vs 6-month-olds, the target genes of DE known sheep miRNAs were involved in 102 GO terms and 7 signaling pathways; in 6- vs 12-month-olds, the target genes of DE known sheep miRNAs were involved in 52 GO terms and 3 signaling pathways; and in 2- vs 12-month-olds, the target genes of DE known sheep miRNAs were involved in 88 GO terms and 6 signaling pathways. Three miR–target regulatory networks were constructed based on these DE miRNA–targets. 9 miRNAs were selected to validate the accuracy of miRNA sequencing data by qRT-PCR. The binding sites of oar-miR-432 with RPS6KA1 was validated by a dual luciferase reporter gene detection system. This is the first integrative analysis of miRNA and mRNA expression profiles in Small Tail Han Sheep ovarian development. These data help elucidate the molecular regulatory mechanisms in sheep ovarian development and identify the biomarkers that influence reproductive performance of Small Tail Han Sheep ewe.
Project description:An Infinium microarray platform (HorvathMammalMethylChip40) was used to generate DNA methylation data from n=168 blood samples of a transgenic sheep model of Huntington's disease. 84 transgenic sheep and age matched control sheep.