| Description: |
(A) Ratios of sex chromosome DEGs are higher than those of autosomal DEGs in the cheek (orange box, comparing MCR vs. FCG) but not in the scalp (gray box, comparing MSG vs. FSG). Each dot represents the ratio for a chromosome. (B) DEGs on the Z chromosome with over four-fold higher expression in males are marked. A log2 fold change value above 0 indicates genes with higher expression in males, while a value below 0 indicates the higher expression in females. The blue lines indicate the value above 2 or below −2. The orange color indicates DEGs from the cheek comparison, while gray color indicates DEGs from the scalp comparison. (C) TPM levels of the sex-linked gene SLC45A2 among the cheek colors of three variants (R: red, W: white, and B: black). An asterisk marks the statistically significant difference between groups (padj < 0.05, log2 Fold Change > 1 or < −1). (D) Sex chromosomes for male and female and a hypothetical model of sex-linked gene SLC45A2 on Z chromosomes within the three variants of cheek colors. The saturation of red cheek color in MCR is closely related to high expression of SLC45A2 from two copies. In contrast, the significantly reduced expression of SLC45A2 in the light red cheek (MCW) from two copies, which is lower than that from a single copy in female gray cheek (FCG), may be resulted from mutation or negative regulation on SLC45A2 . |