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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。 相似文献
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检查鱼类性别和性腺发育的活体取样法 总被引:1,自引:0,他引:1
在鱼类人工繁殖工作中,经常需要在繁殖季节之前,鉴别出鱼的性别,以便有计划地配比放养。有些鱼能从外形区分性别,如青鱼、草鱼、鲢鱼、鳙鱼等,但另一些鱼,如鲻鱼,梭鱼不能从外形上正确判别性别。国外已广泛应用导管活体取样法,检查鱼类性别和研究性腺发育情况。我们于1986年在启 相似文献
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性别决定与分化是生命发育的基本事件,性别决定与分化机制一直是生命科学研究的热点问题。贝类具有雌雄同体、雌雄异体、雄性先熟和性转换等复杂的性别类型,是研究无脊椎动物性别决定与分化机制及其演化进程的理想动物类群。挖掘贝类性别决定与分化调控基因,阐明相关基因的调控作用,对于揭示贝类性别决定与分化的分子机制具有重要意义。本文就贝类性别决定与分化相关基因的研究进展进行了综述,并对该研究领域进行展望,以期为贝类的性别决定和分化机制、生殖操作和遗传改良等研究提供参考。 相似文献
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鱼类的性别决定和性染色体 总被引:7,自引:5,他引:7
全世界现存鱼类约有 2 4 6 18种 ,分属 5 7目 ,4 82科 ,4 2 5 8属 ,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性和重大的经济价值。在脊椎动物系统进化中 ,鱼类处于承先启后的地位 ,有着长久的进化历史和繁多演化分枝。鱼类在进化过程中表现出各种趋同性、趋异性和保守性 ,变化纷繁 ,物种进化异常活跃[1] 。鱼类作为较低等的脊椎动物 ,在性别决定中也有多种表现形式 ,例如鱼类中有些物种是雌雄同体的 ,这在其它高等脊椎动物中是没有的。即在同一个体中同时具有两种性腺 ,行自体受精。而另有些物种则是连续性雌雄同体鱼… 相似文献
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Morphology, endocrinology, and environmental modulation of gonadal sex differentiation in teleost fishes 总被引:1,自引:0,他引:1
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. 相似文献
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半滑舌鳎的性腺分化和温度对性别决定的影响 总被引:18,自引:2,他引:18
半滑舌鳎(Cynoglossus semilaevisGünther)是近年来新开发的一种理想的增养殖对象,雌性个体生长速度比雄性快2~3倍。由于温度可影响多种鱼类的性腺分化,因而探索温度对该鱼的性别决定和性腺分化的影响,获得性逆转雄性亲本,用于培育全雌后代,具有重要的应用前景和经济效益。通过石蜡组织切片,对半滑舌鳎早期性腺分化进行组织学观察。发现在24℃饲养条件下,孵化后30 d半滑舌鳎性腺开始分化,其中具有裂隙的性腺原基未来发育为卵巢,而不具裂隙的原基未来发育为精巢。在孵化后25~100 d对半滑舌鳎进行不同温度(16℃、20℃、24℃、28℃、32℃)处理,在9月龄时利用石蜡组织切片鉴定表型性别,观察温度对性腺分化的影响,结果表明,28℃和32℃高温能显著提高群体中的雄性比例,使其分别达到69.2%和66.7%;而低温16℃和20℃对性腺分化影响不大,群体中雄性比例分别为56.5%和57.1%;24℃处理群体中雌雄个体比例接近1∶1。半滑舌鳎雌性特异的遗传性别鉴定技术也检测到高温和低温处理组出现了由基因型雌性向表型雄性逆转的雄性个体。这些结果表明温度影响了半滑舌鳎性腺分化方向。 相似文献
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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,… 相似文献
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Toru Kobayashi Ryo Ishibashi Shinji Yamamoto Satoshi Otani Koichi Ueno Osamu Murata 《Aquaculture Research》2011,42(2):230-239
The timing of primordial germ‐cell (PGC) migration with regard to the gonadal anlagen, gonad formation and sex differentiation was examined histologically in the chub mackerel (Scomber japonicus) at 5–190 days post hatching (dph). At 5 dph, PGCs appeared on the peritoneal epithelium surface or in the mesentery, on the dorsal side of the abdominal cavity. By 10 dph, stromal cells around the PGCs proliferated. The gonadal primordium was formed by 15 dph. The gonadosomatic index was 0.01% at 30 dph and increased thereafter (0.32% in females and 0.04% in males at 160 dph). Ovarian differentiation occurred at 30–40 dph, indicated by ovarian cavity formation (elongation and fusion of the upper and lower ovarian edges). Meiosis was subsequently initiated. A few meiotic oocytes surrounded the cavity at 50 dph; most were in the perinucleolus stage at 60 dph and attained a diameter of 60–70 μm at 190 dph. Testicular differentiation occurred at 30 dph, indicated by the formation of the sperm duct primordium. Spermatogonia gradually proliferated, developing into spermatocytes at the chromatin–nucleolus stage (after 90 dph) and subsequently into spermatids and spermatozoa (160 dph). These data could aid the development of seeding and cell‐engineering technologies for scombrid fish. 相似文献
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The aim of this review is to present an overview of the sex differentiation and sex determination processes in eels in relation to the urgent need to provide scientific knowledge to better protect and manage the Anguilla genus. Indeed, the global decline of the three main temperate eel stocks, Anguilla anguilla, Anguillidae (Fisheries Management and Ecology, 2003, 10, 365); Anguilla japonica, Anguillidae (Casselman, Eel Biology, Springer Japan, 2003, 293) and Anguilla rostrata, Anguillidae (Tatsukawa, Eel Biology, Springer, Japan, 2003, 255), raises concerns about the necessity to better understand all stages of the life cycle of eels (Righton and Walker, Journal of Fish Biology, 2013, 83, 754). Little is known about the mechanisms involved in the production of males and females in this species with environmental sex determination. Previous reviews identifying the density of individuals as the major factor influencing sex determination were undertaken (Krueger and Oliveira, Environmental Biology of Fishes, 1999, 55, 381; Reviews in Fish Biology and Fisheries, 2005, 15, 37). Here, we review the current advances on the subject, focusing on the roles of early growth rate and interindividual relationships, which are mechanisms underpinned by density, as well as the sex differentiation process, and we question how this knowledge might influence global conservation measures. 相似文献
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养殖中华鲟性腺发生与分化的组织学研究 总被引:15,自引:0,他引:15
用组织切片方法研究人工繁育中华鲟的性腺发生及两性分化过程。中华鲟出膜后3d,原始生殖细胞以单细胞的形式存在于肾管区腹下方。出膜后11d,生殖褶形成,到2月龄和7月龄时,性腺中分别出现血管和脂肪组织,直到8月龄性腺均处于两性未分化状态,划分为0期。9月龄(体重0.6~1.1kg),性腺出现组织学水平上的两性分化,性腺划入I期。I期性腺中,精(卵)原细胞进行有丝分裂。以初级精(卵)母细胞出现作为Ⅱ期开始的标志,精巢和卵巢分别于1.8~2.2年龄(1.55~5.6kg)和2.5~3.0年龄(3.1~8.2kg)进入Ⅱ期。3年龄以后,性腺发育分化陆续达到肉眼可分辨性别的程度,5~5.6年龄(18~35.5kg)时,所有的性腺能肉眼区分雌雄,但精巢和卵巢仍都处于Ⅱ期,其中卵母细胞的卵径为60~240μm。 相似文献
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Ronald George Oldfield 《Fish and Fisheries》2005,6(2):93-110
Genetic and environmental factors may interact to control sex determination in fishes. A common pattern of initial female differentiation and subsequent male transformation before maturation in non‐hermaphroditic fishes and after maturation in sequentially hermaphroditic fishes has suggested that changes in developmental timing may be responsible for the evolution of various expressions of sexual lability. Sequential hermaphroditism is rare in freshwater fishes, but investigators report degrees of sexual lability at four distinct life stages in cichlid fishes. Some cichlids undergo genetic sex determination and are not labile. Lability at the larval stage allows temperature or pH to determine sex. Social interactions apparently determine sex at the juvenile stage in the Midas cichlid (Amphilophus citrinellus). Most reports of post‐maturational sex change in cichlids are anecdotal or unsubstantiated. The common occurrence of same‐sex spawning suggests that many species are incapable of sex change. Sequential hermaphroditism is concluded not to be typical, except for the checkerboard cichlid (Crenicara punctulata), which regularly undergoes functional female‐to‐male transformation. Expression of sexual lability at four life stages in one family of fishes corroborates a role for developmental timing in the evolution of sequential hermaphroditism as well as environmentally controlled sex determination. The broad phylogenetic distribution of sexual lability in cichlids indicates that processes capable of producing sex change are generally present. The rarity of sequential hermaphroditism in cichlids and possibly other freshwater fishes is likely due to unpredictability of food and therefore potential mate distributions compared with coral reef habitats. 相似文献