长牡蛎MITF基因表达及与壳色的关联  

Expression of MITF gene and its correlation with shell color in Crassostrea gigas

作　　者：杨佳敏 王勇[1] 王晓通 包永波[1] YANG Jiamin;WANG Yong;WANG Xiaotong;BAO Yongbo(College of Biological&Environmental Sciences,Zhejiang Wanli University,Ningbo 315100,China;Agricultural College,Ludong University,Yantai 264025,China)

机构地区：[1]浙江万里学院生物与环境学院,浙江宁波315100 [2]鲁东大学农学院,山东烟台264025

出　　处：《水产学报》2020年第6期915-923,共9页Journal of Fisheries of China

基　　金：国家自然科学基金(31672678,41876193);国家重点研发计划(2018YFD0901400);宁波市国际合作项目(2016D10017);浙江省“生物工程”重中之重学科学生创新计划项目(CX2017044);山东省泰山学者专项(tsqn201812094);山东省自然科学基金(ZR2019MC002)。

摘　　要：为了解长牡蛎MITF基因的表达及其与壳色的关联,验证了长牡蛎中的4个MITF基因,对长牡蛎MITF氨基酸序列进行了序列分析和多序列比对,分析了长牡蛎幼体发育各时期的转录组,采用荧光定量PCR的方法研究长牡蛎各组织及黑壳、白壳牡蛎特定部位mRNA表达情况。4个MITF基因中有3个基因可能为假基因,有表达的长牡蛎MITF基因共编码448个氨基酸,为亲水性不稳定蛋白,含有N端结构域(MITFTFEBC3N superfamily)和高度保守的功能性结构域HLH结构域。转录组分析发现MITF在长牡蛎个体发育的各个时期均有表达,在稚贝期达到最高。组织表达结果显示MITF在外套膜中的表达水平显著高于其他组织。MITF在黑壳牡蛎闭壳肌中的表达量显著低于白壳牡蛎,而在黑壳牡蛎外套膜中的表达量高于白壳牡蛎,但不显著。在黑壳、白壳牡蛎外套膜边缘的表达量都显著高于内侧。研究表明,长牡蛎MITF基因可能在牡蛎壳形成早期就参与了黑色素的生成调控和个体的生长发育,可调控牡蛎酪氨酸酶Tyr2基因,参与外套膜和贝壳中黑色素的形成。本研究为进一步研究牡蛎壳色形成机制奠定了基础。In order to understand the expression of MITF gene and its association with shell color in the Pacific oyster Crassostrea gigas,we verified the four MITF genes in oyster,analyzed the sequence and compared with multiple sequences of other species.And the transcriptome of each stage of oyster development was analyzed.We also studied the mRNA expression in different tissues and mantle of black shell and white shell oysters.We found that three of the four MITF genes were pseudogenes,which were confirmed by transcriptome and RT-PCR,and the only expressed MITF gene in oyster encodes 448 amino acids.MITF protein is a hydrophilic and unstable protein and contains a N-terminal domain(MITFTFEBC3N superfamily)and HLH domain which is a highly conserved functional domain.Transcriptome analysis found that MITF was expressed at various stages of ontogeny of C.gigas,and the expression reached the highest level at the juvenile stage.The results of mRNA expression in tissues showed that the expression level of MITF in mantle was significantly higher than those in other tissues.The expression level of MITF in the adductor muscle of oysters with black shell was significantly lower than that of oysters with white shell.However,the expression level in the mantle of oysters with black shell was higher than that of oysters with white shell,but not significant.Both in black and white shell oysters,the expression of MITF gene in the outer edge of the mantel is significantly higher than in the inner edge.The results show that MITF gene of C.gigas might participate in the regulation of the melanin’s formation and the development of oysters at the early stage of oyster shell formation,and it might also regulate tyrosinase Tyr2 gene of oyster and participate in the formation of melanin in mantle and shell.This study lays a foundation for further study on the formation mechanism of shell color in oysters.

关 键 词：长牡蛎 MITF 基因表达 壳色关联 黑色素 

分 类 号：Q785[生物学—分子生物学] S917.4[农业科学—水产科学]