Abstract

The Manila clam, Ruditapes philippinarum, is an ecologically and economically important marine bivalve species. In this study, we conducted transcriptomic sequencing of two different shell color strains (O and Z) before color appearance (uncolored juvenile clam) and pigmented shell color (colored juvenile clam) and investigated the analysis of the differential expression patterns of specific genes associated with pigmentation by RNA-seq and time course qPCR analysis. The transcription level of 16 differentially expressed genes (DEGs) related with shell color was analyzed by qRT-PCR to validate the performance of RNA-seq from Illumina sequence data where most of them were up-regulated. Two genes were down-regulated after the occurrence of zebra clam stripes compared with uncolored zebra clam. The trend of gene expression obtained by qPCR was basically consistent with that of RNA-seq. The synthesis of melanin in bivalves plays potential roles in the pigmentation of the shell and is closely related to the formation of the surface pattern. The porphyrin metabolism combined with tyrosinase and melanogenesis signaling pathway is a novel finding in shell color determination of R. philippinarum. This study sheds light on the pigmentation and coloration mechanism of the Manila clam.

摘要

马尼拉蛤蜊，菲律宾蛤蜊, 是一种在生态和经济上都很重要的海洋双壳类动物。在这项研究中，我们对两种不同壳色菌株（O 和 Z）在颜色外观（无色幼蛤）和有色壳色（有色幼蛤）之前进行了转录组测序，并研究了与通过 RNA-seq 和时程 qPCR 分析进行色素沉着。通过 qRT-PCR 分析了 16 个与外壳颜色相关的差异表达基因 (DEG) 的转录水平，以验证来自 Illumina 序列数据的 RNA-seq 的性能，其中大多数基因上调。与未着色的斑马蛤相比，斑马蛤条纹出现后有两个基因下调。qPCR得到的基因表达趋势与RNA-seq基本一致。双壳类动物黑色素的合成在壳的色素沉着中起着潜在的作用，并与表面图案的形成密切相关。卟啉代谢结合酪氨酸酶和黑色素生成信号通路是测定贝壳颜色的新发现菲律宾河豚。这项研究揭示了马尼拉蛤的色素沉着和着色机制。