前臀鮡上颌和胸鳍特化皮肤组织结构特征和基因表达调控OA

Pareuchiloglanis anteanalis is an endangered endemic species native to the upper Yangtze River.To adapt to fast-flowing highland river environment,the skin structures in its upper jaw and fin-ray regions have undergone specialization,providing strong adhesive capabilities.To elucidate the regulatory ba-sis of this specialization,we examined the histological features of the specialized skin,performed compara-tive transcriptomic analyses between specialized skin(from the upper jaw and pectoral fin)and non-special-ized skin(from the fin-ray region),screened and identified genes associated with skin specialization.The re-sults showed that the specialized epidermis of the upper jaw and pectoral fin develops dense ridges,grooves and sensory bud structures,which enhance adhesion.Tissue-origin mapping showed that these specialized tissues formed adjacent clusters with highly similar gene expression profiles and strong homology.Compared to the non-specialized skin from the fin-ray region,the upper jaw and pectoral fin shared 251 differentially expressed genes(DEGs),including 146 upregulated and 105 downregulated genes.KEGG enrichment anal-ysis indicated that the significantly enriched pathways were primarily purine metabolism(ko00230),TGF-β signaling pathway(ko04350),and calcium signaling pathway(ko04020).qRT-PCR validation con-firmed that adcy5 was significantly upregulated in the specialized skin(P<0.05).In summary,P.anteana-lis develops dense epidermal ridge-groove structures and sensory buds in the upper jaw and pectoral fin to enhance adhesion,adapting to the fast-flowing highland river environment.This skin specialization process is primarily driven by key pathways such as cell projection assembly and collagen metabolism,and the sig-nificant upregulation of adcy5 suggests its potential regulatory role in skin specialization.