Project description:Zygotic genome activation (ZGA) is essential for early embryo development. Here, we reported that ZGA is initiated at 16-cell stage in sheep, as extensive alterations in gene expression and DNA methylation patterns, along with elevated levels of RNA polymerase II and developmental arrest was found at the 16-cell embryos. To uncover the sophisticated RNA metabolism during ZGA, we conducted weighted gene co-expression network analysis and identified 1957 critical maternal genes. Using dapars, we found 1058 and 933 lengthened alternative polyadenylation (APA) events, and genes exhibiting shorten APA were highly expressed in both sheep and mice ZGA-stage embryos. Using rMATs, we reported 2675 and 1963 genes showed exon skipping during ZGA in sheep and mice. These genes are related to RNA binding, translation, gamete generation, and reproduction.
Project description:To explore functional lncRNAs during sheep muscle growth, we systematically investigated lncRNAs using strand-specific Ribo-Zero RNA Sequencing at three key developmental stages of Hu sheep (110-day fetus, 5-day-old lamb and 2-year-old adult)
Project description:Follicular development is a highly coordinated process in Hu sheep. Follicle-cyclic recruitment, spatial displacement, follicle atresia, and ovulation are implicated events resulting from the somatic cells' release of molecular signals. Hu sheep is a high-quality sheep breed with high fecundity in China and is ideal for investigating high reproductive traits. In the current study, the sheep with lambing number ≥3 in three consecutive lambing records were assigned to the HLS group, and lambing number = 1 as the LLS group selected from the same farm with three consecutive lambings. Three randomly picked ewes were slaughtered within 12 h of estrus, and unilateral ovarian tissue was collected and analyzed by single-cell RNA sequencing in each group. A total of five types of somatic cells were identified, and corresponding expression profiles were mapped in the ovaries of the Hu sheep. Additionally, the results of the difference in ovary somatic cell expression profiles between HLS and LLS present that the differences between multiples vs. singleton Hu sheep were mainly clustered in the GCs. In addition, 4 granulosa cell subtypes were identified. GeneSwitches results revealed the opening of JPH1 expression and the closure of LOC101112291, which leads to different evolutionary directions of the granular cells. The expression levels of FTH1 and FTL in GCs of Hu sheep in the HLS group were significantly higher, which inhibited necroptosis and ferroptosis of mural-GCs from decreasing follicular atresia. This study constructed the cellular atlas of the ovary and revealed related biological characteristics at the cellular molecular level. It provides a theoretical basis for the mechanisms underlying the differences in ovulation numbers, which contributes to breeding high-fertility sheep and molecular genetics-based selection.