Fig. 2.

Identification of perinatal germ cell clusters. (A) UMAP plot of germ cells from E18.5, P2 and P7 mouse testes. Left, germ cell subsets; right, sample source. Number of cells in each cluster: T1-ProSG (138), I-ProSG (103), T2-ProSG (168), SSC-1 (634), SSC-2 (419) and Diff-SG (440). (B) Heatmap of DEGs from the germ cell subsets. Top: cell types; left: number of DEGs; right: representative enriched biological processes and genes. (C) CDKN2A is a pan germ cell marker during the perinatal stage. Top: the UMAP plot of Cdkn2a expression in all testicular cell types and in germ cells. Bottom: IF analysis of P2 testis section co-stained with antibodies against CDKN2A and TRA98. Scale bar: 20 µm. (D) DNMT3L is a T1-ProSG marker. Left: UMAP and Violin plots of Dnmt3l expression. Right: IF analysis of P0-P5 testes sections co-stained with antibodies against DNMT3L and KI-67. Scale bar: 20 µm. (E) UMAP plots showing expression of candidate gene markers for both I- and T2-ProSG. (F) IF analysis of P2 and P3 testes sections stained with the antibodies shown. The sections were co-stained with an antibody against KI-67. Scale bar: 20 µm. Right: quantification of the candidate markers-positive cells that co-stain or not with KI-67 and are in the indicated compartment at P2. n, number of cells counted. (G) Model of germ cell development during the perinatal period, see text for details.