Figure 4

Enrichment of gonadal sex-specific differentially expressed genes (DEGs) in BaP exposure-specific DEGs. (A) Analysis flow chart. Primordial germ cells (PGCs) isolated from E13.5 embryonic gonads of OG2 descended from pregnant, vehicle-exposed F0 mice were subjected to RNA-seq to determine sex-specific DEGs (left column). RNA-seq data of PGCs isolated from F1–F3 E13.5 male gonads with F0 exposure to BaP or F0 exposure to vehicle from E6.5–11.5 (F1) or E6.5–15.5 (F2, F3) were examined to obtain p-value ranked lists of exposure-specific DEGs (right column). The same procedures were performed for the RNA-seq data of PGCs isolated from F1-F3 female gonads (not shown). Numbers of sex-specific DEGs within the exposure-specific DEGs were calculated for up to 200 exposure-specific DEGs with the smallest p-values. (B) Heatmap of unsupervised hierarchical clustering of PGC transcriptomes. Locations of sex-specific DEGs are shown by colored bars on the right with representative DEGs. (C, D, E) Enrichment of sex-specific DEGs in the exposure-specific DEGs calculated for PGCs in (C) all generations of embryos, (D) PGCs in the F1 embryos, (E) PGCs in the F2 embryos, or (F) PGCs in the F3 embryos. Y-axis shows relative frequencies of sex-specific genes (blue and red lines show male- and female-specific genes, respectively). X-axis shows numbers of exposure-specific genes with smallest p-values. Numbers of exposed embryos examined for each panel are shown in parentheses in upper left. Numbers of embryos isolated from vehicle exposed control animals were as follows: 17 males and 17 females for panel C, 5 males and 5 females for panel D, 6 males and 6 females for panel E, and 6 males and 6 females for panel F.