Abstract：
Marine bivalves are economically important and exhibit a remarkable diversity in shell color. The Pacific oyster Crassostrea gigas stands out as an important economic species, with the successful development of four distinct color strains through selective breeding. While previous studies have shed light on the genetic mechanism underlying color segregation, the precise molecular regulatory mechanisms responsible for shell coloration in oysters remains elusive. In this study, we confirmed that the golden phenotype is primarily attributed to pheomelanin by histological and ultrastructural observations. Additionally, we conducted a comparative transcriptome analysis of the black and golden shell color oysters to explore the potential genes and pathways contributing to the golden phenotype in C. gigas. Our results revealed a significant increase in differentially expressed genes in the golden phenotype associated with pathways such as glutathione metabolism, and calcium signaling pathway, suggesting a potential role in the synthesis of pheomelanin. Of particular note, we highlighted the potential role of two-pore channel 2 (TPC2) in modulating tyrosinase activity and melanosomal pH, ultimately determining the shade of pigmentation. Our study in this work provided a preliminary exploration of the mechanism, shedding light on the melanosome microenvironment and shell color.
摘要：
海洋双壳类动物在经济上很重要，并且在壳颜色上表现出明显的多样性。太平洋牡蛎Crassostreagigas是重要的经济物种，通过选择性育种成功开发了四个不同颜色的菌株。虽然以前的研究已经揭示了颜色分离的遗传机制，牡蛎壳着色的精确分子调控机制仍然难以捉摸。在这项研究中,通过组织学和超微结构观察，我们证实了黄金表型主要归因于pheomelanin。此外,我们对黑色和金色壳色牡蛎进行了比较转录组分析，以探索导致C.gigas金色表型的潜在基因和途径。我们的结果表明，与谷胱甘肽代谢等途径相关的黄金表型差异表达基因显着增加，和钙信号通路，这表明了在pheomelanin合成中的潜在作用。特别值得注意的是，我们强调了双孔通道2（TPC2）在调节酪氨酸酶活性和黑色素体pH中的潜在作用，最终决定了色素沉着的阴影。我们在这项工作中的研究提供了初步探索的机制,在黑素体微环境和外壳颜色上发光。
