扇贝闭壳肌“分子杂合”特征的遗传调控基础解析

Scallop is one of the important coastal marine breeding shellfish with high economic value. Its huge adductor received widespread concerns from physiologists, geneticists and breeding scholars. However, there still lacks a systematic and comprehensive understanding of muscle myogenesis, development and genetic regulation so far, due to the lagged research on molecular biology of shellfish. Our previous study found that, different from the muscle system of model organisms, scallop adductor muscle shows "molecularly heterozygous" characteristics, that is, marker genes specifically expressed in different muscle types of model organisms show high expression in both the scallop striated and smooth muscles. The "heterozygous" expression pattern of some genes were also reported in other lower invertebrates, suggesting that this "molecularly heterozygous" state may be an ancient existing form of muscle. Meanwhile, preliminary results shows that scallop muscle also presents different characteristics in regulation of muscle myogenesis and differentiation compared to model organisms. Based on these above, in this study we plan to use the methods of multi-omics and molecular biology to systematically analyze the genetic basis of the "molecularly heterozygous" characteristics of scallop muscle, in order to comprehensively understand the molecular mechanisms of muscle myogenesis, development and regulation in shellfish. Our research will also provide theoretical guidance for the breeding of fine varieties.

扇贝是我国沿海重要的经济价值养殖贝类之一，其硕大的闭壳肌长期以来也受到生理学者、遗传学者和育种学者的广泛关注。但由于贝类分子生物学研究起步较晚，目前对贝类肌肉的发生、发育及其遗传调控基础仍缺乏系统、全面的认识。我们课题组前期研究发现，与模式生物不同，扇贝肌肉在分子组成上呈现 “分子杂合”状态，即模式生物中不同肌肉类型特异表达的marker基因在扇贝横纹肌和平滑肌中均有较高表达,部分基因“杂合”的表达模式在其他无脊椎动物中也有报道，暗示这种“分子杂合”可能是肌肉的一种古老的存在形态。同时，初步分析发现扇贝肌肉在发生和分化的调控上也呈现出与模式生物不同的规律。在此基础上，本研究拟综合利用多组学技术和分子生物学研究手段，系统解析扇贝肌肉“分子杂合”特征的产生和遗传调控基础，以深入理解贝类肌肉发生、发育和调控的分子机制，并为辅助扇贝优良品种的选育提供理论指导。

扇贝是我国沿海重要的经济价值养殖贝类之一，其硕大的闭壳肌长期以来也受到生理学者 、遗传学者和育种学者的广泛关注。我们课题组前期研究发现，与模式生 物不同，扇贝肌肉在分子组成上呈现 “分子杂合”状态，即模式生物中不同肌肉类型特异表 达的marker基因在扇贝横纹肌和平滑肌中均有较高表达,部分基因“杂合”的表达模式在其他 无脊椎动物中也有报道，暗示这种“分子杂合”可能是肌肉的一种古老的存在形态。同时，初 步分析发现扇贝肌肉在发生和分化的调控上也呈现出与模式生物不同的规律。本研究以虾夷扇贝闭壳肌为研究对象，以闭壳肌的“分子杂合” 特征为出发点，综合运用多种生物学技术和手段获取肌肉“分子杂合” 的分子基础并探索了杂合肌肉在胚胎发育至成体过程中的产生过程，构建并解析了杂合肌肉的生长调控网络并获得marker基因的上游调控基因在扇贝和模式动物中表达模式的异同。本研究的开展为系统了解肌肉的分子组成和遗传调控提供了新的线索，同时也为优化扇贝优良品种的选育提供了候选基因资源。