鱼类褪黑素合成酶系编码基因的系统进化与生理功能  

Phylogenetic evolution and physiological roles of the four genes encoding melatonin-synthesizing enzymes in various fishes:An overview

作　　者：卞超 张新辉 张凯 魏汉银 何哲 文正勇 黄玉 石琼 BIAN Chao;ZHANG Xinhui;ZHANG Kai;WEI Hanyin;HE Zhe;WEN Zhengyong;HUANG Yu;SHI Qiong(Laboratory of Aquatic Genomics,College of Life Sciences and Oceanography,Shenzhen University,Shenzhen 518057,China;BGI Academy of Marine Sciences,Shenzhen 518081,China;Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River/College of Life Sciences,Neijiang Normal University,Neijing 641100,China;Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China)

机构地区：[1]深圳大学生命与海洋科学学院水产基因组学实验室,广东深圳518057 [2]深圳市华大海洋研究院,广东深圳518081 [3]内江师范学院生命科学学院/长江上游鱼类资源保护与利用四川省重点实验室,四川内江641100 [4]中国科学院水生生物研究所,湖北武汉430072

出　　处：《中山大学学报（自然科学版）（中英文）》2025年第1期158-171,共14页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家重点研发计划(2022YFE0139700);深圳大学特聘教授科研启动项目(纵20231060)。

摘　　要：褪黑素是一种小分子神经递质,主要在脊椎动物的松果腺中合成与分泌,到达机体各部位来参与调控生物节律、生殖、生长与发育等生理过程。在鱼类中,松果腺是一个复合体,主要由类光感细胞构成,具有感光与内分泌双重功能。褪黑素的生物合成从色氨酸开始,涉及色氨酸羟化酶(TPH)、芳香族L-氨基酸脱羧酶(AAAD)、芳香烷胺-N-乙酰转移酶(AANAT)和乙酰色胺甲基转移酶(ASMT)。前期,我们通过对众多脊椎动物开展比较基因组学研究,发现这4个褪黑素合成酶系编码基因的系统进化与脊椎动物的物种进化基本一致,表明这些基因(同褪黑素一样)都很保守。有意思的是,在鱼类中各催化酶基因拷贝数出现显著增加,但四倍体与二倍体鱼中的拷贝数并不一定是2∶1,这是因为鱼类基因组复制后存在部分基因丢失的现象。此外,在大多数鱼类基因组中还鉴定到一些新基因,譬如aaad-like和asmt-like,可能拥有新的功能;有的催化酶基因缺失、出现移码突变或假基因化,可提升物种对特殊生境(诸如洞穴或深海)的生存适应性。本综述主要以我们团队近十年来的相关工作为主线,综合简介鱼类褪黑素合成酶系编码基因的系统进化与生理功能,以期深入理解褪黑素对鱼类生殖内分泌活动的影响,为进一步促进鱼类性腺发育、人工繁殖和分子育种等提供指导和支撑。Mainly synthesized in the pineal gland of various vertebrates including fishes,melatonin as a small-molecule neurotransmitter plays important roles in biological rhythms,reproduction,growth and development.In diverse fish species,pineal is a complex with photoreceptor-like cells as the major pinealocytes,displaying both photoreceptive and endocrine functions.Beginning with the initial precursor tryptophan,melatonin biosynthesis is catalyzed by four enzymes,including tryptophan hydroxylase(TPH),L-aromatic amino acid decarboxylase(AAAD),aralkylamine N-acetyltransferase(AANAT),and acetylserotonin-O-methyltransferase(ASMT,previously known as HIOMT).In the past few years,we performed a series of comparative genomics studies on many representative vertebrates,and obtained a consensus of phylogenetic evolution between these genes and those examined species,suggesting the high conservation of these melatonin-synthesizing genes(MSGs).Interestingly,copy numbers of these genes have been expanded in most fish species,although the ratio of each gene between tetraploidy and diploidy fishes is not always 2:1,possibly due to gene loss after the putative teleost genome duplication(s).Meanwhile,we identified several new genes,such as aaad-like and asmt-like,which may play novel function(s).In some cave-restricted or deep-sea fishes,gene loss,frameshift mutation,and/or pseudogenization of certain MSGs occurs for potential adaptation for the special environment.Focusing on our related findings in the past decade,this review mainly summarizes phylogenetic evolution and physiological roles of the four MSGs,with an aim for better understanding of melatonin and its impacts on fish reproductive endocrine activities.This brief overview will also provide a guidance and the support for practical applications of melatonin and MSGs for regulation of fish gonadal development,artificial breeding,and new variety development in various fishes.

关 键 词：褪黑素 褪黑素合成酶 系统进化 生理功能 适应机制 

分 类 号：Q31[生物学—遗传学]