Dissecting primate early post-implantation development using long-term in vitro embryo culture

Abstract

The transition from peri-implantation to gastrulation in mammals entails the specification and organization of the lineage progenitors into a body plan. Technical and ethical challenges have limited understanding of the cellular and molecular mechanisms that underlie this transition. We established a culture system that enabled the development of cynomolgus monkey embryos in vitro for up to 20 days. Cultured embryos underwent key primate developmental stages, including lineage segregation, bilaminar disc formation, amniotic and yolk sac cavitation, and primordial germ cell–like cell (PGCLC) differentiation. Single-cell RNA-sequencing analysis revealed development trajectories of primitive endoderm, trophectoderm, epiblast lineages, and PGCLCs. Analysis of single-cell chromatin accessibility identified transcription factors specifying each cell type. Our results reveal critical developmental events and complex molecular mechanisms underlying nonhuman primate embryogenesis in the early postimplantation period, with possible relevance to human development.

Spatially resolved gene regulatory and disease vulnerability map of the adult Macaque cortex

“…We next assessed how the single-cell epigenetic profiles correlate with single-cell transcriptomic profiles by applying Smart-seq2 based snRNA-seq (19) to PFC, M1 and V1 of the macaque neocortex ( Figure 1A and Figure S2A). After quality filtering and cell clustering, we profiled the transcriptome from 11,477 single-nuclei (6,949 from PFC, 1,971 from M1 and 2,557 from V1) and identified 17 distinct clusters which were displayed by UMAP visualization (Figure 2A, Figure S2B and S2C, Table S1).…”

“…Sorted nuclei transcriptome amplifications were prepared by a modified SMART-seq2 protocol (19). After nuclei lysis, 1.…”

“…Single-cell RNA-seq data were processed as previous described (19), first, one-hundred-base-pair paired-end reads were pre-processed to remove adapters and filter out reads with low quality using default parameter by Cutadapt (v1.15) (70).…”

Amnion signals are essential for mesoderm formation in primates

“…Unravelling the pathways that form this regulatory network in primates is key for understanding primitive streak formation in humans and for identifying potential causes for congenital malformations and early pregnancy loss. Recently, two publications on cynomolgus embryogenesis [10,11] and one publication on human embryogenesis [12] have created a framework of post-implantation development in primates and characterized the major cell populations involved in gastrulation. However, their interplay and the transcriptional networks guiding this essential step remain unknown.…”

High-resolution transcriptional and morphogenetic profiling of cells from micropatterned human embryonic stem cell gastruloid cultures

“…Cells in Endoderm-2 cluster were enriched for PGC markers NANOS3 and TFAP2C (Sasaki et al, 2016;Ma et al, 2019;Niu et al, 2019;Zheng et al, 2019) (Figure S2E), suggesting the presence of hPGCLCs in gastruloids. Additionally, this cluster has a similar gene expression profile to that reported for cynomolgus monkey PGCs (Sasaki et al, 2016), expressing SOX17, TFAP2C, PRDM1, POU5F1, NANOG, and T, with low or absent SOX2 level ( Figure S2G-I).…”