Paramyosin is a key component of thick filaments in invertebrate muscles. In this study, we isolated the full length cDNA of paramyosin from Pacific oyster (Crassostrea gigas), and determined its pattern of expression during myogenesis. The full length paramyosin (CgPM) cDNA contains an open reading frame (ORF) of 2586 bp encoding a 861-amino acid protein. Sequence analysis revealed an assembly competence domain (ACD) and a heptad repeat (d-e-f-g-a-b-c) with 28-residue repeat zones in the CgPM primary structure, a characteristic of coiled-coil protein. Quantitative analysis of CgPM expression revealed a sharp increase in trochophore stage, and peaked at the D-shaped stage. Strong CgPM expression was found in smooth adductor muscle, followed by striated adductor muscle and mantle tissue. Whole-mount in situ hybridization (WISH) showed a restricted pattern of CgPM expression in adductor muscle, larval velum retractor and foot muscles at the umbo and eyed larval stages. These data indicate that CgPM is strongly expressed during larval myogenesis in C. gigas, which provides the basis for further functional studies of paramyosin in oyster to better understand the molecular and cellular mechanisms of muscle formation in mollusks.

副肌球蛋白是无脊椎动物肌肉粗丝的关键成分。在这项研究中，我们从太平洋牡蛎 ( Crassostrea gigas) 中分离了副肌球蛋白的全长 cDNA ，并确定了其在肌生成过程中的表达模式。全长副肌球蛋白(CgPM) cDNA 包含一个 2586 bp 的开放阅读框 (ORF)，编码 861 个氨基酸的蛋白质。序列分析揭示了一个装配能力域 (ACD) 和一个七肽重复 (defgabc)，在 CgPM 一级结构中具有 28 个残基重复区，这是卷曲螺旋蛋白的特征。CgPM 表达的定量分析揭示了承载体阶段的急剧增加，并在 D 形阶段达到峰值。在平滑的内收肌中发现了强烈的 CgPM 表达，其次是横纹内收肌和外套膜组织。整装原位杂交 (WISH) 在 umbo 和有眼的幼虫阶段显示内收肌、幼虫帆牵开器和足部肌肉中 CgPM 表达的受限模式。这些数据表明 CgPM 在C. gigas幼虫肌发生过程中强烈表达，这为进一步研究牡蛎中副肌球蛋白的功能奠定了基础，以更好地了解软体动物肌肉形成的分子和细胞机制。