Transcriptome analysis reveals the genetic basis underlying the development of skin appendages and immunity in hedgehog(Atelerix albiventris)

Background: The expression of hair features is an evolutionary adaptation resulting from interactions between many organisms and their environment. Elucidation of the mechanisms that underlie the expression of such traits is a topic in evolutionary biology research; however, the genetic basis of skin appendage development and differentiation remains poorly understood. Therefore, we assessed the de novo transcriptome of the hedgehog ( Atelerix albiventris ) at three developmental stages and compared gene expression profiles between abdomen hair and dorsal spine tissues. Results: We identified 328,576 unigenes in our transcriptome, among which 3,598 were differentially expressed between hair- and spine-type tissues. We identified 3 keratin genes related to hair and spine development through comparative analysis of tissues before and after growth of skin appendages. Dorsal and abdomen skin tissues 5 days after birth were compared and the resulting differentially expressed genes (DEGs) were mainly enriched in keratin filament, intermediate filament, epithelium cell differentiation, and epidermis development based on GO enrichment analysis, and tight junction, p53, and cell cycle signaling pathways based on KEGG enrichment analysis. Expression variations of MBP8, SFN, Wnt10, KRT1 , and KRT2 may be the main factors regulating hair and spine differentiation for the hedgehog. Strikingly, DEGs in hair-type tissues were also significantly enriched in immune-related terms and pathways with hair-type tissues exhibiting more upregulated immune genes than spine-type tissues. Thus, we propose that spine development was an adaptation that provided protection against injuries or stress and reduced hedgehog vulnerability to infection. Conclusion: Our study provided a list of potential genes involved in the regulation of skin appendage development and differentiation in A. albiventris . This is the first transcriptome survey of hair traits for a non-model mammal species, and the candidate genes provided here may provide valuable information for further studies of skin appendages and skin disorder treatments.