半滑舌鳎雌、雄鱼myostatin基因差异表达的初步研究

Gender Differential Expression of myostatin Gene in Chinese Tongue Sole(Cynoglossus semilaevis)

半滑舌鳎(Cynoglossus semilaevis)生长具有明显的性别二态性,性成熟雌鱼体重显著高于雄鱼。鱼体肌肉占体重的40%~60%,肌肉生长是生长性状的核心,而myostatin(mstn)基因是肌肉生长发育的负调控因子,对成肌细胞的增殖具有抑制作用。本研究旨在探究肌肉生长发育过程中,mstn基因在半滑舌鳎雌、雄鱼的时空表达模式及其与雌、雄鱼生长差异的关系。结果显示,在所检测的1龄鱼的9个组织中,mstn在肌肉中的表达量最高。不同发育时期的肌肉组织定量结果显示,1龄和2龄雄鱼中的表达量显著高于雌鱼(P<0.05),而在选取的其他时期,雌、雄鱼之间的表达量不存在显著差异。原位杂交结果显示,mstn基因的表达位置在肌纤维边缘,即成肌细胞增殖分化的位置。本文系统研究了肌肉生长发育的负调控因子mstn在半滑舌鳎雌、雄鱼中的时空表达模式,为深入研究半滑舌鳎雌、雄鱼生长差异的原因及其机制提供了基础。

Chinese tongue sole(Cynoglossus semilaevis)growth exhibits clear sex dimorphism,and the weight of mature female fish is significantly greater than that of male fish.In fish,muscle accounts for 40%-60%of body weight,and muscle growth is the core growth trait.Myostatin(mstn),also known as GDF-8,is a member of the transcriptional growth factor(TGF-β)superfamily.mstn is a negative regulator of muscle growth and development and has an inhibitory effect on myoblast proliferation.mstn gene deletion can lead to an increase in skeletal muscle mass.In recent years,research on the mstn gene has primarily focused on the aspects of gene cloning,expression pattern analysis,and RNA interference.Minimal studies have reported the differential expression of the mstn gene between male and female fish with sex dimorphism.The aim of this study was to explore the spatiotemporal expression pattern of the mstn gene in different sexes of Chinese tongue sole during muscle growth and development.The results showed that mstn expression was detected in the liver,spleen,intestine,kidney,gonad,gill,heart,brain,and muscle of 1-year-old fish,and mstn expression was the highest in muscle.The quantitative results of muscle tissue at different developmental stages showed that the expression levels in one-and two-year-old males were significantly higher than those in females(P<0.05),however,there was no significant difference in expression levels between males and females in other selected stages.Tissue section staining showed that the muscle fiber cross sections presented an irregular polygonal shape.The results of in situ hybridization showed that mstn gene expression was found at the edge of the muscle fiber,where myoblasts proliferate and differentiate.In this study,the spatial and temporal expression patterns of mstn were systematically studied in different sexes of Chinese tongue sole,which provides a basis for further studies on the growth differences between male and female Chinese tongue sole.