主要经济双壳贝类性别分化的分子机制概述

本文简要概述了主要经济双壳贝类性别分化分子机制研究进展,介绍国内外研究性别分化和性别决定的代表性双壳贝类物种及主要研究成果,主要涉及牡蛎科(Ostreidae)、扇贝科(Pectinidae)、珍珠贝科(Pteriidae)等常见的经济物种,分子层面涵盖了核酸、蛋白质和激素等,通过综述这些物种相关研究的现状,展望双壳贝类性别分化研究的发展趋势,以期加深对双壳贝类性别分化和性腺发育的认识,为解析虾夷扇贝(Patinopecten yessoensis)及其他双壳贝类性别分化分子机制研究理清思路。     

鱼类性别相关基因FTZ-F1的研究进展

FTZ-F1基因属于孤核受体超家族成员,最初是在果蝇(Drosophila)中发现的,该基因在果蝇胚胎发生的早期调控体节分化基因ftshi-tarazu(FTZ)表达。目前已经发现了很多它的同源基因。研究证明它在类固醇生成、性别分化过程中都发挥着重要的作用。鱼类在脊椎动物系统进化中处于承前启后的地位,是脊椎动物中分布最广、种类最多的类群,具有多种多样的生物学特征和重大的经济价值,所以对于鱼类性别决定机理的研究具有重大意义。文章就鱼类中发现的性别相关基因FTZ-F1,及该基因在胚胎发育过程中的作用、在性逆转鱼中的作用及与芳香化酶的相互作用关系等进行了综述,旨在为系统研究鱼类性别决定机制提供参考。     

罗非鱼性别决定和分化机制的研究进展

罗非鱼染色体遗传型性别决定机制(Chromosomal genetic sex deterruination,GSD)的研究歼展较早,目前利用种间杂交的方法得到全雄罗非鱼在生产上已广泛应用,而对影响罗非鱼性别决定的环境因素研究开展较晚.研究证实罗非鱼确实存在温度依赖型性别决定机制(Temperature-dependent sex determination,TSD),而且这种温度依赖型性别决定机制只出现在性别发育的某一特定时期.近年来,研究者们开始尝试用分子生物学手段来研究罗非鱼性别决定及分化机制,寻找影响性别决定的基因位点、研究位点之间的相互关系及其相互作用,以及外界因素是如何通过调控性别决定位点来影响鱼类性别分化的等.目前研究的主要功能基因有DMRT基因家族、DAX1、SHP、AMH、oP450arom等.最新研究结果表明,tDMRT1,可作为尼罗罗非鱼精巢分化的分子标记.[中国水产科学,2009,16(1):139-145]     

鱼类性别决定的研究进展

有关鱼类性别决定的研究主要集中在温度、性激素、芳香化酶以及随机重复序列、核受体基因等对性别分化的调控方面。由于鱼类所处分类地位较低 ,生活环境千差万别 ,鱼类性别决定没有一个普遍的模式 ,目前研究的鱼类又各不相同 ,因此象哺乳动物那样的性别决定级联模式还没能阐述。本综述旨在阐述近几年有关鱼类性别决定机制方面的研究动态和进展 ,为系统研究鱼类性别决定机制提供参考     

鱼类性别决定机制及相关基因研究进展

鱼类性别决定机制是脊椎动物中最复杂的。同高等脊椎动物一样,鱼类性别决定的基础依然是遗传基因。鱼类的性别控制对于水产养殖有着十分重要的指导意义。目前用于生产实践的鱼类人工性别控制方法有很多,但大多数仍然处于探索与实验阶段,理论上的作用机理仍未研究透彻。文章旨在通过对鱼类性别决定机制、性别决定相关基因等方面国内外研究进展的阐述,为鱼类性别控制、调控养殖鱼类的经济性状如生长率和个体大小等,提供有益的参考资料。     

黄喉拟水龟性别调控相关lncRNA和mRNA的筛选及初步分析

性别异形在动物界广泛存在,长期以来一直是生物学中的热门话题。黄喉拟水龟性别分化属温度依赖型,其温度响应分子机制仍不清楚。为了进一步解析龟鳖动物性别分化的分子机制,本研究初步比较分析了黄喉拟水龟转录本中性别差异表达(different expressed, DE)的长链非编码RNA(long noncoding RNA, lncRNA)及其调控的靶基因。首先,运用Illumina深度测序平台,通过转录组测序(RNA-Seqs)对黄喉拟水龟的精巢和卵巢进行了比较转录组学分析并筛选鉴定出雌雄差异转录本,共筛选获得8 237个DE mRNA和9 573个DE lncRNA。通过GO功能注释及 KEGG通路富集分析发现,上述差异转录本主要参与龟鳖动物性别分化和性腺发育等相关信号通路。此外,通过顺式和反式作用分析,筛选获得了一系列与生殖发育相关的(性腺发育和性别分化)受DE lncRNAs调控的靶基因。本研究为进一步阐明黄喉拟水龟温度依赖型性别的分子机制提供了线索,特别是为进一步挖掘利用龟鳖动物性别决定因子,进行龟鳖动物性控育种技术研究奠定了基础。     

十足目甲壳动物性别控制与单性养殖研究进展

十足目甲壳动物性别决定与分化途径有多种方式,其中多数表现出雌雄二态性模式。本文综述了十足目甲壳动物性别决定和分化分子调控机制的研究进展,总结了在其中发挥重要作用的眼柄、促雄腺等组织,以及IAG和dmrt等关键基因的功能,探讨通过激素诱导和RNA干扰技术等获得十足目甲壳动物单性群体的性别控制方案,以期为十足目甲壳动物性别控制深入研究和单性苗种养殖提供参考。     

TGF-β信号通路在鱼类性别决定与分化中的作用

脊椎动物性别分化和性腺发育的分子机制保守,但不同类群的最上游的性别决定基因却大不相同,尤其是鱼类,其性别决定基因表现出明显的多样性。性别决定包括环境性别决定和遗传性别决定,环境性别决定主要受温度、光照、激素和pH等的影响,而遗传性别决定一般由位于性染色体上的性别决定基因决定。转化生长因子-β(transforming growth factor β, TGF-β)信号通路参与介导了多种生物学过程,近年来很多研究表明,鱼类有多个性别决定基因都是TGF-β信号通路的成员,且该信号通路对于鱼类的性别分化也有重要的作用。本文总结了鱼类已报道的性别决定基因或候选基因,详细综述了TGF-β信号通路在鱼类性别决定与分化中的各种功能,并探讨了该信号通路参与鱼类性别决定的可能机制,这对认识TGF-β信号通路在鱼类性别决定、分化中的作用和性控育种有重要意义。     

性别决定基因(Sox9,DMRT1)在水产动物的研究与应用探讨

性别决定(sex determination)涉及遗传、发育和进化等领域,开展性别决定机制的研究对认识动物性分化异常等多种与性别有关的疾病、实现动物性别的人为控制等都有着重大的现实意义,同时还可为生物进化的分析提供新的线索。本文主要阐述两大性别决定基因家族(Sox,DMRT)中Sox9,DMRT1在水产动物的研究,并探讨了在水产养殖动物性别决定基因研究中的应用和意义。     

大黄鱼雌雄性腺长链非编码RNA的挖掘与差异分析

为探究长链非编码RNA在大黄鱼性腺发育与分化中的作用,从雌雄各3尾大黄鱼(Larimichthys crocea)的性腺中提取总RNA,进行去除rRNA的链特异性转录组建库和二代测序。将测序数据比对到大黄鱼参考基因组,经比对、组装共得到来自31675个基因的66088个转录本,严格筛选得到来自3984个基因位点的5162条lncRNA。进一步分析获得了在大黄鱼雌雄性腺中差异表达的mRNA9341个,lncRNA2782个,高度相关的lncRNA-mRNA对1227个;有多个lncRNA靶向已知的性别分化和发育相关基因,其中lncRNA MSTRG.24346与大黄鱼的性别决定候选基因dmrt1距离相近,且相关性极显著。该研究表明lncRNA可能在大黄鱼性别分化中起到重要作用,值得深入研究阐明机制。     

Patterns of sex ratio response to water temperature during sex determination in honmoroko Gnathopogon caerulescens

ABSTRACT:   The sex ratios of the offspring of males from broods of honmoroko Gnathopogon caerulescens that displayed thermolabile sex determination (TSD), and those from eggs collected from the wild, strongly suggest that the combination of parents plays an important supplementary role in TSD in this species. The proportion of females in all broods from eight pairings of fish captured in the field decreased significantly at 30°C compared to 20°C, and one brood was entirely female at the lower temperature. These results suggest that phenotypic males (XX-males) exist in nature, probably as a result of sex change from genetic females caused by TSD. Sex ratios in relation to water temperature fall into five patterns, two of which seem to result from normal pairings of XX-females and XY-males, and from pairings of XX-males and XX-females with non-thermosensitivity. Two other patterns are thought to result from the same types of pairing, but with thermosensitivity. The last pattern, which shows male bias at both low and high temperature, is not explained only by the combination of genotypic sex determination (XX/XY) and TSD. Fluctuating temperatures close to natural conditions showed little potential to masculinize broods laid in the field between April and early June. However, the sex ratios of fish spawned in early June showed male bias at low and high temperatures. The sex determination mechanism in G. caerulescens may involve the interaction between temperature and sex-determining genetic factors, and the relative importance of each component differs with breeding season.     

鱼类的性别决定与人工控制

鱼类性别的人工控制是鱼类育种中一个十分重要的领域。本文概述了鱼类的性别决定机制及鱼类生理性别的表现方式,同时介绍了鱼类性别的多种人工控制方法,为育种单位的生产实践提供参考。     

Sex change in coral reef fish

Gonadal differentiation can take many forms in fish, ranging from gonochorism, where individuals directly develop as male or female and finally possess only testis or ovaries at sexual maturation, to hermaphroditism where the same individuals can produce mature male and female gametes at some time in their lives. Hermaphrodite fish are, thus, an excellent model for studying the plasticity of sex determination and differentiation in vertebrates. We have shown that sex steroids play a principal role in sex differentiation and sex change in fish. Our laboratory implements several fish models that undergo sex change from female to male or male to female or in both directions. In this review, we will briefly discuss recent advances in our understanding of the mechanism of sex change in coral reef fish.     

鱼类性别决定的遗传基础研究概况

动物从受精卵发育到具有不同性别特征的个体是一个奇妙而又严谨的过程,是人类长期以来试图揭示的自然现象。上世纪90年代初在人类Y染色体上发现了性别决定基因SRY[1],进而发现了一个新的Sox基因家族[2]。上述基因的发现,促进了以哺乳类为代表的动物性别决定和分化机制研究。由于鱼类在脊椎动物中的特殊进化地位、庞大的种类数量以及显著的社会经济价值,鱼类的性别决定研究一直受到遗传和发育学者的重视。尽管离最终阐明鱼类性别决定的机制还有距离,但近20多年来鱼类性别决定的遗传基础研究已取得不少重要进展。本文试图根据现有文献资料,…     

雌雄同体鱼类性别分化及性转变研究进展

在脊椎动物中,鱼类具有多样的性别分化方式,大致可分为雌雄异体、雌雄同体以及单性生殖3类.一般情况下,鱼类性别决定后,性腺可分化为卵巢或精巢,并且在整个生命周期内保持不变.而在雌雄同体鱼类,其性别可以从雌性转变为雄性、雄性转变为雌性或者在雌雄两种性别间进行多次转变.雌雄同体鱼类具有多种性别转变形式,是研究脊椎动物性别决定...     

Morphology, endocrinology, and environmental modulation of gonadal sex differentiation in teleost fishes

Successful reproduction by an adult depends on the normal ontogenesis of the gonads, a complex process of cellular and histological differentiation that starts early in life. This process is theoretically predetermined by genetic factors and includes sensitisation of the bipotential gonads to endogenous endocrine factors prior to, during and even after commitment to maleness or femaleness. However, young fish are relatively vulnerable to a host of environmental (physical and chemical) factors that can affect this endogenous endocrine axis, disturbing or even overriding the putative developmental pathway. This sexually lability can be exploited to our advantage for the production of monosex fish populations of the most valuable sex for food production or aquarium fish trade. On the other hand, it represents also a potential path for undesirable influences from endocrine-disrupting chemicals and climatic factors, particularly environmental temperature. This paper provides a detailed account of the early histological process of gonadal sex differentiation, with special reference to gonochoristic species, and reviews the criteria employed to positively identify ovarian and testicular differentiation. It also reviews the development of endocrine competence and sensitivity of the differentiating gonads to exogenous influences in the context of the relative stability of genotypic sex determination in various fish species. Sex differentiation in some species seems to be under strong genetic control and may not require endogenous sex steroid production. Conversely, reliance on endogenous sex steroids for gonadal differentiation is observed in other species and this phenomenon is apparently associated with a higher incidence of environment (mainly temperature)-labile sex differentiation. This revised version was published online in July 2006 with corrections to the Cover Date.     

A review of sex determination and searches for sex‐specific markers in sturgeon

The availability of monosex populations of caviar‐producing female sturgeon would considerably enhance the economic viability of domestic caviar production systems. However, it is not possible to distinguish males from females by morphological characters at larval, juvenile and even adult stages. The mechanism of sex determination in sturgeons is poorly understood, and to date no sex‐specific markers in sturgeon have been reported. This review concentrates on the methodologies used to elucidate the mode of sex determination in sturgeon species and provides information on the molecular tools used to determine genetic sex markers.     

斑马鱼性别决定相关基因的表达分析

本研究选择一些可能参与斑马鱼性别决定相关的基因（cyp19a、cyp19b、gata4、dmrt1和wt1）,通过RT-PCR和实时荧光定量PCR技术分析各个基因在斑马鱼发育不同时期（64细胞期(2h)、256-512细胞期(2.5h)、囊胚球体期(4h)、30%外包(4.6h)、50%外包(5.2h)、75%外包(8h)、胚孔封闭期(10h)、10-15体节期(15h)、成型期10-20 (32h)、孵化期(60h)、幼苗期(120h)、7天、10天、12天、14天、16天、18天、20天、22天、24天、26天、28天和30天）的表达情况。结果显示：cyp19a与cyp19b基因随着胚胎的发育表达量逐渐增加,在28天-30天达到最高;gata4基因在胚孔封闭期表达量最高随后降低;dmrt1基因在30%外包期表达量最高随后逐渐递减;wt1基因在10-15体节期表达量最高随后逐渐递减并保持稳定的表达。     

Genetic techniques for control of sexuality in fish farming

Recent developments in Ministry of Agriculture, Fisheries and Food (MAFF) laboratories in the genetic control of sexuality in fish are briefly reviewed. Techniques include the development of a range of spawning times, the control of sex-ratio and the elimination of sexual maturity by induced polyploidy.