A comparative study of skin transcriptomes and histological observations for black and white hair colors of giant panda

The Giant pandas (Ailuropoda melanoleuca) are mammals belonging to the bear family, order Carnivora, and their characteristic hair color and distribution has been in the spotlight. In recent years, the gradual prevalence of skin diseases in giant pandas and even the discovery of albino individuals have made the study of the substrate of their skin hair distribution more and more urgent. In this study, by comparing the skin histology and transcriptomes for hairs of different color of giant pandas, we found that the melanin contents of hair follicles at the bases of black and white hairs differed, but the hair follicles at the base of white hairs also contained some amount of melanin. The transcriptome sequencing results showed that there were great differences in the expression of the transcriptome of the skin under different hair color blocks, in which the number of differentially expressed genes in the white skin was much smaller than that in the black skin. Transcriptomes for skin tissue samples for different hair colors revealed several enriched Kyoto encyclopedia of genes (KEGG) pathways that include tumor, cell adhesion and melanocyte growth-related signaling pathways. This study provides a theoretical basis for subsequent studies on hair color distribution and skin diseases in giant pandas.