半滑舌鳎hsd11b1l和hsd11b2基因的克隆及其温度响应的表达规律

Molecular Characterization and Expression Patterns of hsd11b1l and hsd11b2 and Their Response to High Temperature Stress in Chinese Tongue Sole Cynoglossus semilaevis

皮质醇在鱼类应对外界环境压力的过程中起到重要调控作用,而hsd11b1l和hsd11b2具有调节体内皮质醇浓度的重要功能。本研究克隆了半滑舌鳎(Cynoglossus semilaevis) hsd11b1l和hsd11b2基因的cDNA全长序列,分析了其序列特征,研究了其时空表达特征及温度响应的表达规律。结果显示,hsd11b1l cDNA全长为1650 bp,开放性阅读框长度为864 bp,编码287个氨基酸;hsd11b2 cDNA全长为4526 bp,开放性阅读框长度为1209 bp,编码402个氨基酸。半滑舌鳎不同组织和性腺发育时期的表达分析结果显示,hsd11b1l在肝脏中表达量最高,在卵巢的表达量是精巢的2倍,且在6月龄和3龄鱼的卵巢中呈现较高表达;而hsd11b2主要在精巢中表达,在6月龄鱼的精巢中表达量最高,随后表达量急剧降低,在卵巢中各个时期几乎不表达。半滑舌鳎温度响应的表达结果显示,高温(28℃)处理2个月后,与正常温度(22℃)对照组相比,hsd11b1l和hsd11b2在雄鱼中的表达量均显著降低(P<0.05);高温短期应激48h,hsd11b1l表达在雌鱼和雄鱼中均显著降低,hsd11b2表达仅在雄鱼中有显著下调(P<0.05)。本研究探讨了hsd11b1l和hsdl1b2基因在半滑舌鳎性别分化过程中的表达规律,为研究环境温度与半滑舌鳎性别分化之间的关系奠定了基础。

Sex determination and differentiation in fish are not only influenced by genetic factors, but also controlled by environmental factors. Previous studies have shown that cortisol plays an important role in the feedback of environmental stress in fish. Fish hsd11b1l and hsd11b2 can regulate the concentration of cortisol. In this study, we cloned full-length cDNA of hsd11b1l and hsd11b2, and analyzed their sequence characteristics in Chinese tongue sole(Cynoglossus semilaevis). We then detected their spatiotemporal expression characteristics and expression patterns after temperature stress. The full-length cDNA of hsd11b1l was 1650 bp with 864 bp open reading frame encoding a predicted 287 amino acid protein. While the full-length of hsd11b2 was 4526 bp with 1209 bp open reading frame encoding 402 amino acid protein. The qPCR showed that the highest expression of hsd11b1l was within the liver and the expression level in the ovary was two-fold higher than that in testis. In particular, the expression level of hsd11b1l in the ovary was higher than in testis at the stages of 6 mpf and 3 ypf. The hsd11b2 was expressed mainly in the testis and expression level peaked in testis at 6 mpf. Conversely, expression of hsd11b2 was hardly detected in any stages of ovary development. In addition, we analyzed the expression patterns of hsd11b1l and hsd11b2 after high-temperature(28℃) treatment. The expression levels of hsd11b1l and hsd11b2 was significantly reduced in the gonads of males(P<0.05) after the high-temperature treatment for 2 months. For the acute high-temperature treatment(48 h), the expression of hsd11b1l significantly decreased in the gonads of both females and males(P<0.05), and the expression of hsd11b2 was only significantly down-regulated in the male testis(P<0.05). In this study, the expression patterns of hsd11b1l and hsd11b2 genes in the developmental stages of gonads affected by high temperature stress lays a foundation for understanding the relationship between temperature and sexual differentiation in Chinese tongue sole.