The Long Terminal Repeats of ERV6 Are Activated in Pre-Implantation Embryos of Cynomolgus Monkey

ABSTRACT: Precise temporal development is an important event during embryo development. However, transcriptional changes in the temporal development of early epiblast cells (EPI), primitive endoderm (PrE) and trophectoderm (TrB) cells remain unclear. Long terminal repeat elements (LTRs) of ERVs (Endogenous retroviruses) are dynamically expressed in blastocysts of mammalian embryos. However, the expression of LTRs in monkey blastocyst is still unknown. By analyzing publicly available single-cell RNA-sequencing (seq) data, LTRs of several ERV families, including MacERV6, MacERV3, MacERV2, MacERVK1 and MacERVK2 were highly expressed in pre-implantation embryo cells including EPIs, TrB and PrE but absent in post-implantation. We knockdown MacERV6-LTR1a in cynomolgus monkey with short hairpin RNA (shRNA) strategy to examine the potential function of MacERV6-LTR1a in early development of monkey embryo. The silence of MacERV6-LTR1a mainly postpone trophectodermal cell differentiation and cell polarity of TrB, and the genes relate to epithelial proliferation, differentiation and development were downregulated in EPI of shRNA-treated embyos. Addtionally, stem cell differentiation relate genes were downregulated in PrE when MacERV6-LTR1a was silenced. Moreover, we have comfirmed MacERV6-LTR1a can recruit ESRRB (Estrogen Related Receptor Beta). Actually, recent reports demonstrated that ESRRB plays a important role in maintenance of self-renewal and pluripotency of embryonic and trophoblast stem cells through different signaling pathways including FGF and Wnt signaling pathways. In summary, these results suggest that MacERV6-LTR1a potentially regulates the temporal development of pre-implantation embryo of cynomolgus monkey.

ORGANISM(S): Macaca fascicularis

PROVIDER: GSE182061 | GEO | 2021/10/25

REPOSITORIES: GEO