In vitro culture of ovine embryos up to gastrulating stages

Developmental failures occurring shortly after blastocyst hatching from the zona pellucida constitute a major cause of pregnancy losses in both humans and farm ungulates. The developmental events occurring following hatching in ungulates include the proliferation and maturation of extra-embryonic membranes –trophoblast and hypoblast- and the formation of a flat embryonic disc, similar to that found in humans, that initiates gastrulation prior to implantation. Unfortunately, our understanding of these key processes for embryo survival is limited because current culture systems are unable to sustain ungulate embryo development beyond hatching. Herein, we report a culture system that recapitulates most developmental landmarks that characterize ovine development up to gastrulating stages: trophoblast maturation, hypoblast migration, embryonic disc formation, Rauber´s layer removal, epiblast polarization and mesoderm differentiation. In this dataset we compare the transcriptional profile of ovine day (D) 14 in vitro cultured embryos and embryonic day (E) 11 and 12.5 in vivo derived embryos by RNA-seq. RNA-seq analysis was performed in 3 ovine whole embryos in vitro-produced and cultured until D14, 3 E11 and 3 E12.5 in vivo-derived embryos.

囊胚从透明带（zona pellucida）孵出后不久发生的发育失败，是人类与养殖有蹄类动物妊娠丢失的主要原因之一。有蹄类动物孵出后的发育事件包括胚外膜——滋养层（trophoblast）与下胚层（hypoblast）——的增殖与成熟，以及与人类胚胎相似的扁平胚盘形成：该结构会在着床前启动原肠胚形成过程。遗憾的是，我们对这些影响胚胎存活的关键过程的认知仍十分有限，因为当前的培养体系无法支撑有蹄类动物胚胎在孵出后继续发育。本研究报道了一种培养体系，可复现绵羊发育至原肠胚阶段的绝大多数标志性发育事件：滋养层成熟、下胚层迁移、胚盘形成、劳伯层（Rauber's layer）移除、上胚层极化以及中胚层分化。本数据集通过RNA测序（RNA-seq）比较了体外培养至第14天（D14）的绵羊胚胎，与体内来源的第11天（E11）及第12.5天（E12.5）胚胎的转录组特征。本次RNA-seq分析的样本包括3株体外制备并培养至D14的完整绵羊胚胎、3株E11体内来源胚胎以及3株E12.5体内来源胚胎。