College of Ecological Environment and Resources, Qinghai Minzu University, Xining 810007, China; Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining 810001, China; Key Laboratory of Resource Chemistry and Eco-environmental Protection in Tibetan Plateau of State Ethnic Affairs Commission, Qinghai Minzu University, Xining 810007, China.
College of Ecological Environment and Resources, Qinghai Minzu University, Xining 810007, China; Key Laboratory of Resource Chemistry and Eco-environmental Protection in Tibetan Plateau of State Ethnic Affairs Commission, Qinghai Minzu University, Xining 810007, China.
Comp Biochem Physiol Part D Genomics Proteomics. 2024 Jun;50:101217. doi: 10.1016/j.cbd.2024.101217. Epub 2024 Feb 16.
This study compares the skin structures of Rana kukunoris with two different skin colors living in the same area of Haibei in the Northeastern Qinghai-Tibet Plateau. The skin thickness of the khaki R. kukunoris was significantly greater than that of the brown R. kukunoris (P < 0.01), and significantly more mucous and granular glands were present on the dorsal skin of the khaki frog (P < 0.05). Meanwhile, the melanocytes on the dorsal skin of the brown frog were significantly larger than those on the khaki one (P < 0.05). Morphological changes in the expansion and aggregation of melanocytes seemed to deepen the skin color of R. kukunoris. Moreover, transcriptome sequencing identified tyrosine metabolism, melanogenesis, and riboflavin metabolism as the main pathways involved in melanin formation and metabolism in brown R. kukunoris. TYR, MC1R was upregulated as the skin color of R. kukunoris was deepened and contributed to melanin production and metabolism. In contrast, the khaki frog had significantly more upregulated genes and metabolic pathways related to autoimmunity. The khaki frog appeared to defend against ultraviolet (UV) radiation-induced damage by secreting mucus and small molecular peptides, whereas the brown frog protected itself by distributing a large amount of melanin. Hence, the different skin colors of R. kukunoris might represent different adaptation strategies for survival in the intense UV radiation environment of the Qinghai-Tibet Plateau.
本研究比较了生活在青藏高原东北部海北地区的两种不同肤色的华西雨蛙的皮肤结构。土黄色华西雨蛙的皮肤厚度明显大于棕色华西雨蛙（P<0.01），并且土黄色青蛙的背部皮肤上有明显更多的粘液和颗粒状腺体（P<0.05）。同时，棕色青蛙背部皮肤的黑素细胞明显大于土黄色青蛙（P<0.05）。黑素细胞的形态变化似乎加深了华西雨蛙的肤色。此外，转录组测序确定酪氨酸代谢、黑色素生成和核黄素代谢是棕色华西雨蛙中黑色素形成和代谢的主要途径。随着华西雨蛙肤色加深，TYR、MC1R 上调，有助于黑色素的产生和代谢。相比之下，土黄色青蛙有更多与自身免疫相关的上调基因和代谢途径。土黄色青蛙似乎通过分泌粘液和小分子肽来防御紫外线（UV）辐射引起的损伤，而棕色青蛙则通过分布大量黑色素来保护自己。因此，华西雨蛙的不同肤色可能代表了在青藏高原强 UV 辐射环境中生存的不同适应策略。
