Fig. 4

Dynamics of XY gene expression and autosomal gene expression during spermatogenesis. a Percentage of expressed genes in spermatogonia B (SB), pachytene spermatocytes (PS), round spermatids (RS) and elongating spermatids for the sex chromosomes (X and Y), five representative chromosomes (chromosomes 3, 6, 14, 16 and 18) and all autosomes. In spermatogonia B, the proportion of expressed genes is similar between the X chromosome and autosomes. At the pachytene stage of meiosis I, the proportion of X-linked expressed genes is decreased due to MSCI. After meiosis, the proportion of expressed genes is similar between the X chromosome and autosomes. The Y chromosome is depleted in genes expressed before meiosis but enriched in round spermatids expressed genes. The percentage values are indicated in the table. The level of statistical significance is marked with three asterisks (*) if p < 0.001. b RPKM mean values of expressed genes in spermatogonia B, pachytene spermatocytes, round spermatids and elongating spermatids for the sex chromosomes (X and Y), five representative chromosomes (chromosomes 3, 6, 14, 16 and 18) and all autosomes. The expression level of X- and Y-linked genes is similar to that of autosomal genes in spermatogonia B. The value is indicated in the table. c Distribution of RPKM values of expressed genes in spermatogonia B, pachytene spermatocytes and round spermatids. The X-axis represents categories of RPKM range of values (0–2, 2–4, 4–6, etc.), the Y-axis, the percentage of genes in each category. X-linked genes expression values are indicated in pink, Y-linked genes expression values are in green, and autosomal values are in gray. After meiosis, the sex chromosomes are enriched in genes with low expression values. See Additional files 5 and 6 for detailed statistical analyses