Developmental transcriptome and genes related to skin appendage differentiation in hedgehog (Atelerix albiventris)

Abstract Background Hedgehog spines are skin appendages that have evolved as a result of the interaction of their skin with the environment. However, such a differentiation mechanism during skin development leads to a high skin appendage diversity, the origins of which are still not fully understood. Spine-skin and hair-skin offer a natural model for the analysis of the genomic basis for the evolution of epidermal appendage formation. We performed a comparative transcriptomic analysis of hedgehog ( Atelerix albiventris ) at multiple developmental stages, and tried to explore the genetic basis for differentiation and development and the resulting expression of the spine-trait. Results A total 15,158 differentially expressed genes (DEGs) were identified. We determined the gene modules and programs corresponding to the various phenotypic traits at different developmental stages by WGCNA analysis. Objective analysis of gene module expression revealed that HIPPO, TGFB, MAPK and Wnt signaling pathways regulate the activation and cell proliferation and differentiation at the skin-appendage development stage. Further, the key genes encoding keratin, FGF, TEAD, and other proteins regulate molecular localization and the cell cycle for hair development and differentiation. Finally, we found a number of highly expressed immune genes in the skin, suggesting that hedgehog spines, unlike pangolin scales, have evolved independently to protect against predators rather than compensate for low autoimmune immunity. Conclusions The variability of gene expression profiles of hair-type and spine-type at multiple development stages, and key candidate genes and pathways at the molecular level might provide evidence that can help elucidate the genetic basis of skin appendage development and differentiation of hedgehog.