提高奥尼杂交鱼雄性率

何谓奥尼杂交鱼？目前讲的奥尼杂交鱼是用奥利亚罗非鱼雄鱼与尼罗罗非鱼雌鱼杂交得到的子代。奥尼杂交鱼雄性率高、生长快、起捕率高,深受人们欢迎。那么,怎样提高奥尼杂交鱼的雄性率呢？1．双亲纯度要高。奥尼杂交鱼的双亲为奥利亚罗非鱼和尼罗罗非鱼,由于奥利亚罗非鱼的性染色体组成雄鱼为ZZ,雌鱼为ZW,与尼罗罗非鱼及我国“四大家鱼”不同（尼罗罗非鱼雄免性染色体组成为XY,雌鱼为XX）。利用奥利亚罗非鱼雄鱼（ZZ）与尼罗罗非鱼雌免（XX）杂交,它们后代性染色体组成为ZX,在理论上应是百分之百为雄鱼,但实际上获得100％雄性…     

尼罗罗非鱼性诱变个体测交试验研究

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。     

罗非鱼“粤闽1号”及其繁育群体的遗传多样性和遗传关系分析

罗非鱼“粤闽1号”是用尼罗罗非鱼(Oreochromis niloticus)和奥利亚罗非鱼(O. aureus)培育的全雄罗非鱼新品种。采用同工酶电泳技术和线粒体DNA控制区序列分析方法,对罗非鱼“粤闽1号”及其繁育群体的遗传多样性、遗传结构及群体之间的遗传关系进行研究。同工酶电泳结果显示,酯酶(EST)和乳酸脱氢酶(LDH)的酶谱具有组织和群体特异性。肌肉和脾脏中的EST表达量极低,而肝脏中的EST表达量较高,LDH在3种组织中均有较高表达,但酶谱存在差异。在罗非鱼“粤闽1号”及其繁育群体中,共检测到10条EST酶带和5条LDH酶带,多态性位点比例(P)为12.50%~71.43%,平均观测杂合度(Ho)为0.0417~0.6143,Hardy-Weinberg遗传偏离指数(D)为?0.2347~0.9072。线粒体DNA控制区序列分析结果显示,mtDNA D-loop区的碱基组成无显著差异,均呈现出A+T碱基偏向性(63.39%)。在罗非鱼“粤闽1号”及其繁育群体中,共发现20种单倍型,核苷酸多样性指数(Pi)为0~0.0519,奥尼罗非鱼雌鱼(WY1)、尼罗罗非鱼雌鱼(XX)、尼罗罗非鱼雄鱼(XY)和罗非鱼“粤闽1号”(XY2)群体的Pi值(0.0440~0.0519)明显高于超雄尼罗罗非鱼(YY1)、超雄奥尼罗非鱼(YY2)和奥利亚罗非鱼雌鱼(WZ)群体的Pi值(0~0.0009)。各群体之间的遗传分化指数(FST)为?0.0115~0.9963,XY2与WY1群体之间、XX与XY群体之间以及WZ和YY2群体之间的遗传分化不显著(FST<0.05, P>0.05)。XY2群体与尼罗罗非鱼群体(XX群体和XY群体)和奥利亚罗非鱼群体(WZ群体)之间的平均遗传距离分别为0.0639和0.0695。在NJ系统进化树中,XX、XY、YY1和XY2群体聚为一支,WY1、WZ和YY2群体聚为另一支。本研究揭示了罗非鱼“粤闽1号”的生化和分子遗传特征,为其种质鉴定、繁育群体的构建和优良性状的稳定遗传提供理论基础。     

尼罗罗非鱼新品种“鹭雄1号”的制种研究

采用多年定向选育的尼罗罗非鱼(Oreochromis niloticus)雌鱼做母本,采用由性别二系配套技术繁殖的尼罗罗非鱼超雄鱼做父本,构成XX♀/YY♂尼罗罗非鱼新品种繁育体系,可规模化繁育全雄性尼罗罗非鱼新品种"鹭雄1号"。"鹭雄1号"的突出特点是遗传雄性率高,达到99.00%以上,较其它所有尼罗罗非鱼品系的雄性率高出1倍左右,同时具有生长迅速和出肉率高的优良性状。     

黄颡鱼“全雄1号”

黄颡鱼“全雄1号”是今年农业部审定通过的水产新品种,品种登记号：GS-04-001-2010。它是相关科技人员历时十余年攻关而成的智慧结晶。科研人员先采用性逆转、人工雌核发育等技术获得染色体均为YY的超雄鱼与生理雌鱼,再将两者交配后生产的YY超雄鱼作父本与正常雌鱼母本交配,最终培育出黄颡鱼“全雄1号”。     

尼罗罗非鱼生理雌鱼的实验研究

采用雌性激素处理刚孵化出膜的尼罗罗非鱼(Oreochromis niloticus)YY基因型鱼苗,可使性别未分化的合子全部转化为生理雌鱼。该YY型生理雌鱼的卵巢发育正常,具有繁殖机能,可为采用二系配套(YY△♀×YY♂)技术大量生产尼罗超雄鱼提供种源保证。     

WY♀-YY♂型罗非鱼繁殖体系研究

为实现超雄罗非鱼的自然繁殖,按照尼罗罗非鱼(Oreochromis Niloticus)的遗传基础和种质标准,不断选育尼罗WY雌性鱼,然后与尼罗YY超雄鱼相组合,形成尼罗罗非鱼WY♀-YY♂繁殖体系。研究结果显示:WY♀-YY♂繁殖体系能自然繁殖YY超雄鱼和WY雌鱼;能保持性比平衡;不用测交直选超雄鱼。此种繁殖体系可使超雄鱼规模化制种,实现三系配套转变为二系配套制种。     

尼罗超雄鱼的规模化制种与生产应用

为大量繁殖尼罗罗非鱼(Oreochromis niloticus)超雄鱼,利用雌性激素处理刚孵化出膜的YY型鱼苗可使其转化为雌鱼,且具有生殖功能这一关键技术,使原先的"三系配套"技术简化为两系配套,并运用于实际生产。使用该技术建立了YY♂/YY△♀种质库,储备超雄鱼近20万尾,YY型生理雌鱼近万尾,生产XY型全雄鱼近3亿尾,现已应用于福建、海南和广东等省区。     

罗非鱼的种间杂交

<正> 用蓝罗非鱼(Tilapiaaurea)、T.hornorum和尼罗罗非鱼(T.nilotica)进行了控制杂交的研究,以确定哪些杂交组合能产生全雄后代,以及评定杂交种的可育性。T.hornorum(?)×蓝罗非鱼♀和T.hornorum(?)×尼罗罗非鱼♀的杂交组合产生了全雄杂种。其它种间的杂交和种内的交配均产生了两种性别的个体。以每克雌鱼所产生的鱼苗数量计算,小个体的鱼要比大个体的鱼产生的鱼苗多。在杂交和回交中,所有的杂种都是可育的。一、方法本研究是在1976年1～12月在波多黎各     

渔业生物学

030007尼罗罗非鱼性别表型和遗传型以及性比对其生长的影响=Innuenee of sexualphenotype and genot即e,and sex ratioongrowth performanees in til即iao掩ochromis,:izoticu:[刊,英〕门几guyeniA,Faucon-neauB,FostievA…// Aquac.一2002, 6207(3/4)一249一261 罗非鱼早熟,连续产卵,产卵不同步,使具在饵料不足的池塘中的密度过大,成为限制其养殖发展的主要因素之一。有关第1个试验分析了性别遗传型对表型雄鱼生长率的影响。雄鱼有3种不同的遗传型:YYloo(YY雄X YY雌)、XY100(YY雄x XX雌)以及XXloo(激素性诱变的雌鱼)。将它们与传…     

Genetic contribution of parents in sex determination of honmoroko Gnathopogon caerulescens

The honmoroko has been inferred to have an XX/XY sex determination system, but the parental genome can also affect the sex ratio of the offspring. The extent of parental effects on sex determination was examined by checking the sex ratios of F1 and F2 gynogenetic diploids and control diploids. Eleven gynogenetic broods from different females consisted of all or nearly all females, but eight broods showed a variable proportion of males (<50 %). One second-generation brood of gynogenetic diploids consisted wholly of females, but others produced some males. In crosses with a control diploid female, four males from a high-percentage male brood of gynogenetic diploids produced offspring with a balanced sex ratio. Sib-mating between a gynogenetic female and three gynogenetic males from the brood produced predominantly male progeny. These results suggest that there are at least four possible genotypes: genotypic female (XX), phenotypic female carrying a silent Y chromosome, genotypic male (XY), and genotypic supermale (YY). These inferences suggest that this fish has an XY system but a relatively high proportion of females possess a mutated, silent Y chromosome which does not lead to testis formation.     

Chromosome set manipulation and sex control in common carp: a review

The development of techniques for production of gynogenetic, androgenetic, polyploid, and monosex progenies in common carp (Cyprinus carpio L.) is described from a chronological perspective. Gynogenetic progenies were obtained either by suppression of the second meiotic division in eggs (meiotic gynogenesis) or by suppression of the first mitotic division in haploid embryos (mitotic gynogenesis). As a rule, gynogenetic progenies of common carp were all-female, revealing female homogamety (females—XX, males—XY) in this species. Induced gynogenesis results in increased homozygosity; the rate of increase depends on the type of gynogenesis. Inbreeding coefficient (F) for one generation of meiotic gynogenesis in common carp is about 0.6, while diploids obtained by mitotic gynogenesis are homozygous for all genes (F = 1.0). Mitotic gynogenesis was used for production of clones in common carp. In androgenetic progenies of common carp, YY males were identified, that after crossing with normal females (XX) produced all-male progenies. Triploids of common carp are characterized by a significant reduction in gonad development (especially ovaries). However, the reduction in gonad development did not result in an increase of somatic growth rate of fish. The procedure for androgen treatment to induce phenotypic sex reversal in genotypic females (XX) was elaborated. All-female progenies of common carp were produced on a large scale by crossing normal females (XX) with hormonally sex-reversed males (XX). Rearing of all-female progenies in conditions when fish normally reach sexual maturity before reaching of market size increased production yield by 7–8%. In a few cases distant hybridization resulted in polyploidy of fish without application of any physical treatment. The ability of hybrid females between crucian carp (Carassius auratus) and common carp to produce diploid (with unreduced chromosome number) gametes resulted in opportunities to produce triploid and tetraploid hybrid progenies.     

Allelic segregation of sex‐linked microsatellite markers in Nile tilapia (Oreochromis niloticus) and validation of inheritance in YY population

Stocking of all‐male fingerling produced by direct administration of male hormone 17‐α‐methyltestosterone is the most preferred method for present‐day aquaculture of the Nile tilapia Oreochromis niloticus. However, due to the growing concern of negative impact of steroid hormone in food fish, production of ‘genetically male’ tilapia, which depends on the concrete and thorough understanding of sex determination, has long been a scientific curiosity. The objective of the present study was to identify reliable sex‐linked markers and to evaluate the applicability of those markers in terms of monosex production approach. ‘XY’ neofemales were produced by using synthetic oestrogen and identified through selective breeding and progeny testing. Three females with progeny not deviating from 3:1 sex ratio (male:female) were designated as ‘XY’ neofemales and were used subsequently to produce putative YY progeny. Among the fifteen microsatellite markers tested, marker ARO172 was most informative in differentiating male and female genotypes. Twenty‐seven F₂ fish from three families were identified as putative YY males based on marker genotyping, and four of them were crossed to produce F₃ to validate marker association by progeny testing. The YY males produced 86%–100% male progeny indicating ARO172 a unique sex‐linked marker applicable in marker‐assisted selection.     

WY型罗非鱼的性别鉴定

以尼罗罗非鱼(Oreochromis niloticus)和奥利亚罗非鱼(O.aurea)为材料,进行WZ♀×XY♂、WZ♀×YY♂、WY×ZY♂、WY×YY♂杂交实验及其子代分析,确认WY型罗非鱼的性别为雌性。     

Growth performance of mixed sex, hormonally sex reversed and progeny of YY male tilapia of the GIFT strain, Oreochromis niloticus

The growth performance of three experimental groups consisting of mixed sex fish (control), hormone-treated fish and progeny of YY male tilapia, all originated from the genetically improved farmed tilapia (GIFT) strain was evaluated. Masculinization of sexually undifferentiated fry was achieved by providing a supplement of 5 mg of 17-α-methyltestosterone per kg of feed over a period of 21 days (after sac absorption). Both mixed sex and progeny of YY male groups were fed a standard commercial ration. Mixed sex fish did not deviate significantly ( P >0.05) from the 1:1 male to female ratio. Percentages of male averaged 75% in hormone-treated fish and 95% in YY male group over the sampling periods and at final harvest. The effect of sex on weight and length was statistically significant ( P <0.001). The model used to analyse weight and length included experimental group and sex in each culture period as the fixed effects, and replicate cages as the random effect. Over the culture period of 141 days, there were no statistical differences ( P >0.05) in body weight and length between mixed sex, hormonally treated and progeny of YY males. There were also no significant differences in level of variability in harvest weight between three groups of fish when the data were classified into five categories (=<100, 100 to <150, 150 to <200, 200 to <250 and ≥250 g). It is concluded that monosex culture of all male tilapia would be of no advantage over mixed sex culture for the GIFT strain under conditions of cages suspended in earthen ponds.