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The medaka Oryzias latipes is a teleost fish with an XX/XY sex determination system similar to that of mammals. However, under high-temperature conditions, XX medaka are masculinized by an elevation of the key teleost glucocorticoid, cortisol. Cortisol inhibits female-type proliferation of germ cells and induces masculinization of XX medaka during gonadal sex differentiation. To identify masculinization mechanisms downstream of cortisol, we analysed the functions of gonadal soma-derived growth factor (gsdf) and anti-Müllerian hormone receptor type 2 (amhr2); these genes are known to play important roles in the inhibition of germ cell proliferation and male differentiation. We investigated the impact of gsdf and amhr2 on the proliferation of germ cells using gsdf knockout (KO) and amhr2 KO medaka. At hatching stage, loss of gsdf or amhr2 function recovered female-type proliferation in germ cells under cortisol treatment. Moreover, cortisol treatment of gsdf KO or amhr2 KO medaka did not induce masculinization of XX medaka. These results suggest that cortisol inhibits female-type proliferation of germ cells and induces masculinization of XX medaka through GSDF and AMHR2. This study thereby provides the first evidence that GSDF and AMHR2 are involved in cortisol-induced masculinization.
相似文献3.
摘要 为探索StAR基因在中华鳖（Pelodiscus sinensis）性腺发育过程中的作用,利用RACE技术克隆获得中华鳖StAR基因全长cDNA,采用Real-time PCR分析其在不同组织及胚胎不同发育时期的表达情况,并制备多克隆抗体,采用western blot检测StAR在不同组织的表达,通过免疫组化对其在细胞中的表达进行定位,同时检测芳香化酶抑制剂来曲唑处理雄性中华鳖后StAR在精巢中的表达情况。结果显示：该基因全长2377bp,开放阅读框903bp,编码300个氨基酸。氨基酸序列比对及系统进化分析表明,中华鳖StAR与龟类亲缘关系最近。荧光定量PCR结果表明,StAR基因在精巢中表达量最高,显著高于其他组织;StAR基因于中华鳖胚胎发育16期已有表达,20期表达量最高,提示StAR可能参与中华鳖早期性腺分化;来曲唑处理的中华鳖精巢中,StAR表达量显著降低。本研究利用原核表达系统构建中华鳖StAR基因原核重组表达载体,经蛋白纯化后免疫小鼠,获得中华鳖StAR多克隆抗体。Western blot检测结果显示StAR在不同组织的表达量与荧光定量结果基本一致。免疫组化结果显示,StAR蛋白在卵巢间质细胞、精巢的间质细胞,精原细胞及胞质中表达。研究表明,StAR基因可能参与中华鳖性腺发育过程。 相似文献
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前期报道了利用尼罗罗非鱼LG22上性别连锁的分子标记检测到养殖群体存在天然XY雌鱼,但其能否用于培育YY超雄罗非鱼尚不清楚。本研究首先引入遗传性别受LG22染色体严格控制的CQ尼罗罗非鱼群体和具有天然XY雌鱼的WC群体,将CQ群体XY雄鱼与WC XY雌鱼杂交,检验杂交F1 YY超雄鱼是否可用于控制后代性别,并比较杂交F1 XY和YY罗非鱼体质量、性腺指数、血清激素水平和性腺基因表达情况。研究发现,CQ XY雄鱼和WC XY雌鱼交配,获得的F1 中具有25%的YY超雄鱼,经鉴定为全雄且可育。将F1 YY超雄鱼与WC XX雌鱼、WC XY雌鱼（母本）、杂交F1 XX雌鱼和CQ XX雌鱼交配,后代几乎全雄,仅在与F1 XX雌鱼交配后代中有2尾雌鱼（雄性率98%）。在孵化后180 d,杂交F1中XY和YY个体的体重、性腺指数、血清激素水平差异不显著。基因表达分析发现,YY鱼精巢中AmhX/AmhY mRNA表达显著高于XY鱼,而Dmrt1 和Cyp11b2 mRNA表达水平差异不显著。杂交F1 YY和XY鱼生理指标无明显差异。因此,采用尼罗罗非鱼天然XY雌鱼能够培育YY超雄鱼,且该YY超雄鱼能够用于罗非鱼性别控制。 相似文献
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在尼罗罗非鱼性转化试验工作的基础上,有倾向性地选择试验中生长快、个体大或具有雄性副性特征的雌鱼与正常的雄性XY个体自然杂交。通过早期鱼苗性腺压片观察和子代性成熟后雌雄鉴定及个体解剖观察,试验组中出现了典型的XY雄与XY雌鱼杂交的子代1/4雌和3/4雄分布比例,佐证了尼罗罗非鱼遗传型为XX雌-XY雄型。结果表明,XY型雌鱼可存活,性腺可正常发育,并有生殖能力;子代出现3/4的雄性个体也侧证了1/4YY超雄个体存在并可存活的可能性,为进一步试验研究提供了实践依据;XY雌鱼与XX雌鱼存在外观差异,在一定程度上可通过这些性状选择XY雌鱼,为后期单倍体、雌核二倍体试验提供方便。 相似文献
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F. Sakai I. Swapna C. C. Sudhakumari M. V. N. L. Ganesh H. Kagawa T. Kobayashi H. Fan Y. Nagahama B. Senthilkumaran 《Fish physiology and biochemistry》2005,31(2-3):177-181
Gonadal development and steroidogenesis in teleosts is regulated by two gonadotropic hormones; luteinizing hormone (LH) and
follicle-stimulating hormone (FSH). Earlier studies in tilapia have shown that FSH-β and LH-β appear by 14 days after hatching
(dah), results from the current study corroborate with these previous reports in tilapia. Here we demonstrate the appearance
of LH in pituitary between 14 and 20 dah. In addition to this the present study primarily focuses on any possible differences
in appearance of LH-β and FSH-β immunoreactivity between XX and XY population of Nile tilapia. LH immunoreactivity was found
to be lower in pituitary of XX fish when compared to XY fish. The development of FSH-β immunoreactivity in pituitary of the
Nile tilapia is also presented. Overall, it remains to be established what significance these findings on the appearance of
gonadotropins hold for sex differentiation in tilapia.
F. Sakai and I. Swapna contributed equally. 相似文献
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Steroids are known to play a crucial role in gonadal sex differentiation in many non-mammalian vertebrates, but also in the
gonadal sex change of hermaphroditic teleosts. We investigated the expression of two genes encoding key steroidogenic enzymes,
i.e., cytochrome P450 aromatase (P450arom) and cytochrome P45011β-hydroxylase (P45011β), during the sex change of the protogynous
rice field eel, Monopterus albus. Using RT-PCR with degenerate primers, we cloned rice field eel homologous fragments for both genes (rcP450arom and rcP45011β)
as indicated by the high level of homology with P450arom and P45011β sequences from various vertebrates. Gonadal expression
of rcP450arom and rcP45011β mRNA levels were then assessed during the sex change by semi-quantitative RT-PCR and a real-time
RT-PCR. rcP450arom was predominantly expressed in ovary, much less in ovotestis, and barely in testis. Conversely, P45011β
was markedly up-regulated at the onset of testicular development. These findings underline that regulation of steroidogenesis
is an important process in the sex change of protogynous rice field eel, and they clearly indicate that the concomitant down-regulation
of P450arom and up-regulation of P45011β are of pivotal importance to the sex change of this species. 相似文献
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胡子鲇脑型芳香化酶基因全长cDNA克隆及表达 总被引：1，自引：0，他引：1
采用RT-PCR和RACE法,克隆了胡子鲇(Clarias fuscus)脑型芳香化酶基因Cyp19a1b,应用荧光实时定量PCR检测其在前脑、下丘脑、脑垂体、肝、精巢和卵巢6种组织,以及性腺分化前后(出膜后12～30 d)全鱼中的mRNA表达。结果表明,Cyp19a1b cDNA全长2 347 bp,5′端非编码区219 bp,3′端[不包括poly(A)]596 bp,开放阅读框(ORF)1 503 bp,编码500个氨基酸,推测其编码蛋白质分子量为56.388 kD。序列分析及分子系统进化树结果表明,胡子鲇Cyp19a1b氨基酸序列与非洲鲇(Clarias gariepinus)Cyp19a1b同源性最高,达95.6%;与南方大口鲇(Silurusmeridionalis)、黄颡鱼(Pelteobagrus fulvidraco)、斑马鱼(Danio rerio)、斑点叉尾(Ictalurus punctatus)、赤点石斑鱼(Epinephelus akaara)、鲤(Cyprinus carpio)、鲫(Carassius auratus)及稀有鲫(Gobiocypris rarus)Cyp19a1b同源性达75%以上,但与上述鱼类的性腺型芳香化酶基因(Cyp19a1a)同源性低于62%,表明其为脑型芳香化酶,同源性分析结果与根据传统形态学和生化特征分类的结果相一致。荧光实时定量PCR结果显示,Cyp19a1b在胡子鲇上述组织中均有表达,其中下丘脑中表达量最高,肝和精巢最低,在脑部的表达存在明显的性别差异(P<0.05)。此外,在胡子鲇性腺分化前(出膜后12 d)Cyp19a1b即开始表达,但分化前后表达量无显著性差异(P>0.05)。结果暗示Cyp19a1b可能不是引起胡子鲇性腺分化的直接因素,但其可能通过"下丘脑垂体性腺轴"对性腺分化过程产生间接影响。 相似文献
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Wei Wang Hua Zhu Ying Dong ZhaoHui Tian Tian Dong HongXia Hu CuiJuan Niu 《Fish physiology and biochemistry》2017,43(6):1557-1569
Molecular mechanism of sex determination and differentiation of sturgeon, a primitive fish species, is extraordinarily important due to the valuable caviar; however, it is still poorly known. The present work aimed to identify the major genes involved in regulating gonadal development of sterlet, a small species of sturgeon, from 13 candidate genes which have been shown to relate to gonadal differentiation and development in other teleost fish. The sex and gonadal development of sterlets were determined by histological observation and levels of sex steroids testosterone (T), 11-ketotestosterone (11-KT), and 17β-estradiol (E2) in serum. Sexually dimorphic gene expressions were investigated. The results revealed that gonadal development were asynchronous in 2-year-old male and female sterlets with the testes in early or mid-spermatogenesis and the ovaries in chromatin nucleolus stage or perinucleolus stage, respectively. The levels of T and E2 were not significantly different between sexes or different gonadal development stages while 11-KT had the higher level in mid-spermatogenesis testis stage. In all the investigated gonadal development stages, gene dmrt1 and hsd11b2 were expressed higher in male whereas foxl2 and cyp19a1 were expressed higher in female. Thus, these genes provided the promising markers for sex identification of sterlet. It was unexpected that dkk1 and dax1 had significantly higher expression in ovarian perinucleolus stage than in ovarian chromatin nucleolus stage and in the testis, suggesting that these two genes had more correlation with ovarian development than with the testis, contrary to the previous reports in other vertebrates. Testicular development-related genes (gsdf and amh) and estrogen receptor genes (era and erb) differentially expressed at different testis or ovary development stages, but their expressions were not absolutely significantly different in male and female, depending on the gonadal development stage. Expression of androgen receptor gene ar or rspo, which was supposed to be related to ovarian development, presented no difference between gonadal development stages investigated in this study whenever in male or female. 相似文献
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NAOTAKA OMOTO MAMORU MAEBAYASHI ERI MITSUHASHI KOJI YOSHITOMI SHINJI ADACHI KOHEI YAMAUCHI 《Fisheries Science》2002,68(5):1047-1054
The effects of giving oral estradiol-17β (E2 ) and 17α-methyltestosterone (MT) on gonadal sex differentiation in the F2 hybrid sturgeon, the bester ( Huso huso female × Acipenser ruthenus male), are investigated. Giving E2 at 10 μg/g diet to fish from 14 months until 31 months of age induced incomplete feminization and resulted in approximately 40% abnormal ovary development in which oocytes were observed without ovarian lamellar structures and gonadal shape was similar to normal testis. Giving MT at 25 μg/g diet for the same duration failed to induce masculinization, and resulted in approximately 30% undeveloped gonads even at 30–37 months of age. In contrast, E2 and MT at only 1 μg/g diet given from 3 to 18 months of age was sufficient to induce feminization and masculinization, respectively. In these fish, feminization and masculinization were observed at 9 months, when most putative ovaries and testes were histologically distinguishable by the shape of the gonadal surface. These results indicate that sex reversal can be induced in these fish by hormone treatment that is started at 3 months age, before morphological differentiation occurs on the stroma of the gonads. 相似文献
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采用RT-PCR法从大鲵( Andrias davidianus )性腺中分离获得 Cyp51 基因全长cDNA 1 975 bp, 5′端非编码区135 bp, 3′端非编码区331 bp,开放阅读框( ORF)1 509 bp,编码503氨基酸。生物信息学分析显示, Cyp51 基因编码蛋白的二级结构含有50.20%的α-螺旋,9.96%的延伸链,3.59%的β-转角,36.25%的无规则卷曲。系统进化树显示,大鲵与两栖类中的热带爪蟾和非洲爪蟾同源性最高,与其它物种也有较高的同源性。qRT-PCR分析结果显示, Cyp51 基因在卵巢、肝、肾等组织表达水平显著性高于其它各组织;性腺发育不同时期表达结果显示, Cyp51 基因在1-5Y卵巢中表达显著性高于精巢,在6Y时无显著性差异;在雌性与伪雌性性腺中表达水平显著高于雄性及伪雄性性腺。结果表明 Cyp51 基因对大鲵的性腺分化,尤其是卵巢发育有着重要作用。 相似文献
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Ganesan Nagarajan Adimoolam Aruna Ching-Fong Chang 《Fish physiology and biochemistry》2013,39(1):95-101
Despite neurosteroidogenic enzymes are playing important roles in the regulation of brain development and function, the potential link between brain and gonad by the action of steroid hormones during gonadal sex differentiation is still not clear in teleosts. In this mini-review, we summarized our understanding on the early brain development related to the synthesis of neurosteroids and receptor signaling during gonadal sex differentiation in protogynous orange-spotted grouper, Epinephelus coioides (functional females for the first 6 years of life and start to sex change around the age of 7 years) and protandrous black porgy (functional males for the first 2 years of life but begin to change sex during the third year). We found a similar profile in the increased expression of brain aromatase gene (aromatatse B or cyp19a1b), aromatase activity, estradiol (E2), and estrogen signaling in the brain of both grouper and black porgy fish during gonadal sex differentiation. In contrast to mammals, teleost fish Cyp19a1b expressed in a unique cell type, a radial glial cell, which is acted as progenitors in the brain of developing and adult fish. In agreement with these pioneer studies, we demonstrated that the grouper cyp19a1b/Cyp19a1b was expressed in radial glial cells. Further, in vivo data in the grouper brain showed that exogenous E2 upregulated Cyp19a1b immunoreactivity (ir) in radial glial cells. These data suggest the possible roles of Cyp19a1b and E2 in early brain development which is presumably related to gonadal sex differentiation. 相似文献
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性腺型芳香化酶基因是一种调节雌雄激素平衡的基因。为初步探究暗纹东方鲀性腺型芳香化酶基因在性腺发育和性别分化过程中的作用,通过RACE及荧光定量PCR技术,成功克隆出暗纹东方鲀性腺型芳香化酶基因的cDNA全长序列,共1786 bp,编码514个氨基酸,与红鳍东方鲀及星点东方鲀同源性最高。氨基酸序列分析显示,该基因编码的蛋白是一种稳定的亲水性蛋白,但不存在信号肽序列;性腺型芳香化酶含有38个磷酸化位点、4个N-糖基化位点、2个跨膜保守结构域;其氨基酸序列在哺乳动物和鱼类中均十分保守,且含有跨膜区、Ⅰ-螺旋区、Ozol′s肽区、芳香化酶特异性保守区和亚铁血红素结合区等功能保守区。表达分析显示,暗纹东方鲀性腺型芳香化酶基因主要在肌肉和卵巢中表达,其次在其他组织中也有少量表达,而且在幼鱼不同发育期卵巢中的表达量呈现出逐渐升高再降低的表达趋势,在精巢中则基本不表达。研究结果表明,性腺型芳香化酶基因很可能参与了暗纹东方鲀雌鱼性腺分化后卵巢的发育、雌性特征的维持和其他组织的发育等过程。 相似文献
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本研究筛选到圆斑星鲽(Verasper variegatus)的性别相关基因sox9,并通过RACE技术获得了全长序列,基因全长为3287 bp,包括1431 bp的ORF,编码477个氨基酸,368 bp的5¢ UTR和1488 bp的3¢ UTR。在3¢ UTR中有多聚腺苷酸尾和加尾信号AATAAA。通过荧光定量PCR测定了sox9基因在圆斑星鲽成鱼不同组织中的表达水平,发现sox9基因在圆斑星鲽的脑、眼、鳃、心、肝、胆、肠、精巢、卵巢、肾和肌肉等各个组织中都有不同程度的表达。在鳃、脑和精巢组织中检测到较高水平的sox9转录,其中精巢中的转录水平显著高于其他组织,sox9基因在性腺中的表达显示出性别两相性差异。其在精巢中的表达水平要显著高于卵巢,说明sox9基因与雄性性腺发育相关。通过测定sox9基因在圆斑星鲽幼鱼不同发育时期(20、30、40、50、60、70和80日龄)的表达水平,发现其在20~50日龄表达量逐渐下降,在60日龄时表达量上升,推测表达量上升可能与幼鱼性腺分化相关。 相似文献
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Kazufumi Osako Akihiko Fujii Yaowalux Ruttanapornvareesakul Naoki Nagano Koichi Kuwahara Akira Okamoto 《Fisheries Science》2007,73(3):660-667
ABSTRACT: For the purpose of clarifying the differences of taste components between the testis and ovary of the sea urchin Anthocidaris crassispina , variations in free amino acid composition in gonadal extract during gonadal development were investigated using chemical and histopathological methods. Sea urchins were collected at Iki Island, Nagasaki, Japan between 30 April and 5 June 2003, and maturation stages and the free amino acid compositions were determined. The sweet amino acids threonine (Thr), glycine (Gly), and alanine (Ala), the umami amino acid glutamic acid (Glu), and the bitter amino acids lysine (Lys) and arginine (Arg) were the main constituents accounting for more than 80% of total free amino acids. In the testis and ovary, Gly levels were the highest among them and increased with gonadal development. The other free amino acids consisted mainly of bitter amino acids and either showed no variation or decreased with gonadal development. These variations in free amino acid composition were observed more clearly in the ovary than the testis. These findings indicate the possibility of differences in the flavor of sea urchin gonad by sex and gonadal development stages. 相似文献