Liu Yi, Weng Kaiqi, Li Guangquan, Wang Huiying, Tan Yu, He Daqian
Shanghai Academy of Agricultural Sciences, Shanghai, China.
Hunan Wugang Tong Geese Agricultural Development Co. Ltd., Hunan, China.
Poult Sci. 2025 Apr 29;104(8):105233. doi: 10.1016/j.psj.2025.105233.
This study systematically investigated the genetic and metabolic mechanisms underlying pigmentation in goose webbed feet by integrating histological, transcriptomic, and metabolomic analyses. Histological examinations revealed significant differences in melanin deposition among webbed feet of varying colors. Dark black webbed feet exhibited the highest melanin content, light black webbed feet showed moderate levels, and colorless webbed feet lacked detectable melanin. Transcriptomic analysis identified substantial variations in the expression levels of key genes involved in melanin biosynthesis, including TYRP1, PMEL, DCT, TYR, OCA2, MC1R, RAB38, WNT16, CAMK2A, and MLANA, between pigmented and colorless webbed feet. Notably, the OCA2 gene exhibited significantly higher expression in dark black webbed feet compared to light black webbed feet, underscoring its pivotal role in regulating pigmentation intensity. Enrichment analysis emphasized the importance of pathways related to tyrosine metabolism, melanin production, and amino acid biosynthesis in determining pigmentation differences. Metabolomic profiling supported these findings, revealing that L-tyrosine and 5,6-dihydroxyindole-2-carboxylic acid are critical metabolites in the melanin biosynthesis pathway. Specifically, elevated levels of L-tyrosine were detected in colorless webbed feet, likely due to inhibited melanin synthesis, whereas 5,6-dihydroxyindole-2-carboxylic acid levels were highest in dark black webbed feet, reflecting active melanin production. Correlation analysis between transcriptomic and metabolomic data further validated the central role of tyrosine metabolism and melanin biosynthesis pathways in pigmentation. In conclusion, this study employed multi-omics approaches to elucidate the critical role of the OCA2-centered genetic-metabolic regulatory network in melanin deposition of goose webbed feet, providing important insights into the molecular mechanisms of avian pigmentation and valuable references for poultry breeding.
本研究通过整合组织学、转录组学和代谢组学分析，系统地研究了鹅蹼色素沉着的遗传和代谢机制。组织学检查显示，不同颜色蹼之间的黑色素沉积存在显著差异。深黑色蹼的黑色素含量最高，浅黑色蹼的黑色素含量中等，无色蹼则未检测到黑色素。转录组分析确定了色素沉着和无色蹼之间，参与黑色素生物合成的关键基因（包括TYRP1、PMEL、DCT、TYR、OCA2、MC1R、RAB38、WNT16、CAMK2A和MLANA）的表达水平存在显著差异。值得注意的是，与浅黑色蹼相比，OCA2基因在深黑色蹼中的表达显著更高，这突出了其在调节色素沉着强度中的关键作用。富集分析强调了酪氨酸代谢、黑色素生成和氨基酸生物合成相关途径在决定色素沉着差异中的重要性。代谢组分析支持了这些发现，揭示L-酪氨酸和5,6-二羟基吲哚-2-羧酸是黑色素生物合成途径中的关键代谢物。具体而言，在无色蹼中检测到L-酪氨酸水平升高，这可能是由于黑色素合成受到抑制，而5,6-二羟基吲哚-2-羧酸水平在深黑色蹼中最高，反映了黑色素的活跃生成。转录组学和代谢组学数据之间的相关性分析进一步验证了酪氨酸代谢和黑色素生物合成途径在色素沉着中的核心作用。总之，本研究采用多组学方法阐明了以OCA2为中心的遗传-代谢调控网络在鹅蹼黑色素沉积中的关键作用，为鸟类色素沉着的分子机制提供了重要见解，并为家禽育种提供了有价值的参考。
