摘要: |
作为我国鲆鳎鱼类中的一种主要养殖品种,半滑舌鳎(Cynoglossus semilaevis)有时会发生无眼侧黑化(Melanism)、有眼侧白化(Albinism)的体色异常现象。本研究克隆了半滑舌鳎体色相关的酪氨酸酶基因(TYR)和多巴色素异构酶基因(DCT)的cDNA序列,并对这2个基因进行系统发育分析和时空表达分析。实验获得了TYR基因编码区cDNA序列长度为1620 bp,编码539个氨基酸;DCT基因编码区cDNA序列长度为1551 bp,编码516个氨基酸。结果显示,TYR和DCT在20日龄前的鱼苗体内表达量较高,尤其是在变态关键时期(15~20日龄)表达量最高,30日龄时的表达量锐减到很低水平;在其他时期的皮肤组织中,这2个基因在有眼侧正常皮肤和无眼侧黑化皮肤的表达量最高,在有眼侧白化皮肤和无眼侧正常皮肤中表达量极低;在其他时期的其他组织中,在眼睛中的表达量最高,其次是肝脏,在脾脏和肌肉中表达量极低。研究表明,TYR和DCT基因是半滑舌鳎无眼侧黑化发生和有眼侧体色维持的关键基因。本研究为查明半滑舌鳎体色异常机制提供了重要依据和参考。 |
关键词: 半滑舌鳎 体色 酪氨酸酶基因(TYR) 多巴色素异构酶基因(DCT) |
DOI:10.19663/j.issn2095-9869.20200516001 |
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Expression analysis of TYR and DCT genes related to body color in Cynoglossus semilaevis at different periods and in different tissues |
WU Yaolei1,2,3,4, LI Yangzhen1,2,3,4, WANG Na1,2,3, MA Teng1,2,3,4, ZHAO Yuzhu1,2,3,4, CHEN Songlin1,2,3
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1.Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences;2.Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs;3.Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, Shandong 266071, China;4.National Experimental Teaching Demonstration Center of Aquatic Science, Shanghai Ocean University, Shanghai 201306, China
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Abstract: |
Melanin commonly exists in animal tissues. The animal body surface has different colors and abundant pigment patterns due to differences in the distribution and development of melanin and related cells. Different pigment patterns have important functions such as biological camouflage, courtship, etc., especially in fish. Cynoglossus semilaevis, one of the dominant aquaculture flatfish species in China, often suffers from two body color anomalies, i.e. melanism and albinism, which have hindered the development of high-quality seeds and aquaculture. In this study, cDNA sequences of two color-related genes (i.e. TYR and DCT) were cloned and phylogenetically analyzed. Further, expression levels of both genes were analyzed in different stages and in different tissues. The cDNA sequence length of TYR gene coding region is 1620 bp, encoding 539 amino acids. The length of the cDNA sequence in the coding region of DCT gene is 1551 bp, encoding 516 amino acids. In this study, it was found that the expression levels of TYR and DCT were high in fry that were less than 20-day-old, especially during the critical period of metamorphosis (15 to 20-day-old), and decreased to a very low level at 30-day-old. In other skin tissues, the expression levels of these two genes were highest in normal skin on the ocular side and in dark skin on the blind side, and extremely low in albino skin on the ocular side and in normal skin on the blind side. Among other tissues at other times, the highest expression was in the eye, followed by the liver, with very low expression in the spleen and muscles. Results show that TYR and DCT genes are the key genes for blind-side melanogenesis and ocular-side color maintenance in C. semilaevis. This study provides an important basis and reference for identifying the mechanism of color anomaly in C. semilaevis. |
Key words: Cynoglossus semilaevis Body color Tyrosinase gene (TYR) Dopa isomerase gene (DCT) |