雌核发育二倍体鲫鲤杂交克隆品系建立

研究了雌核发育二倍体鲫鲤第2代(G₂)产生的二倍体卵子在无染色体加倍情况下形成第3代(G3)的雌核发育细胞学行为,G₃,G₂×散鳞镜鲤和G₂×四倍体鲫鲤的染色体数目.研究结果表明:(ⅰ)G₂产生的二倍体卵子无需染色体加倍处理,仅在灭活散鳞镜鲤精子激活下,形成了大量G₃.(ⅱ)G₃和雌核发育二倍体鲫鲤第1代(G₁)、G₂一样,也表现出杂交特征,并且都是二倍体(2n=100);G₂与二倍体散鳞镜鲤和四倍体鲫鲤分别交配形成了三倍体(3n=150)和四倍体(4n=200)鱼;(ⅲ)二倍体G₂产生的二倍体卵子在雌核发育过程中,有明显第二极体排出,排除了二倍体卵子源于第二极体保留的可能.另外,还对二倍体鲫鲤产生二倍体卵子的机制进行了讨论.雌核发育二倍体鲫鲤杂交克隆品系建立证明二倍体卵子通过雌核发育形式可形成一个能产生二倍体卵子的新型二倍体鲫鲤品系,二倍体鲫鲤产生二倍体卵子的特殊繁殖方式在生物进化和生产应用方面都具有重要意义.     

鲤科鱼类6个正反交人工异源三倍体胚胎的染色体变化及其发育命运

采用静水压休克保留第二极体的方法,在鲤(♀)×鲢(?)、鲫(♀)×鲢(?)、白鲫(♀)×鲢(?)和鲢(♀)×鲤(?)、鲢(♀)×鲫(?)、鲢(♀)×白鲫(?)6个正反交组合中都诱导出了异源三倍体,但只有正交鲤(♀)×鲢(?)、鲫(♀)×鲢(?)和白鲫(♀)×鲢(?)3个处理组中整倍性的异源三倍体胚胎才有可能正常发育,孵化出苗;而反交鲢(♀)×鲤(?)、鲢(♀)×鲫(?)和鲢(♀)×白鲫(?)3个处理组中的异源三倍体胚胎在发育过程中不断发生染色体排除和丢失,形成非整倍体而死亡,只有少数雌核发育二倍体鲢才能孵化出苗。结果表明,鱼类人工异源三倍体胚胎的发育命运与杂交物种间的基因组大小有关。     

雌核发育兰州鲇胚胎发育和形态特征的研究

该研究通过紫外线(UV)灭活的黄颡鱼(Pelteobagrus fulvidraco)精子利用冷休克方法诱导兰州鲇(Silurus lanzhouensis)雌核发育二倍体(G_(2n))、单倍体(N)、杂交二倍体(H_(2n)),以及同源精子诱导的普通二倍体(2N)的胚胎发育时序和发育生物学特征进行了观察比较。结果显示,(1)受精率为2NH_(2n)NG_(2n),孵化率为2NG_(2n)N,畸形率为NG_(2n)2N。(2)在水温23 °C下,普通二倍体48 h孵化出膜,雌核发育二倍体51 h孵化出膜,杂交二倍体在神经胚期(26 h 20 min)停止发育,单倍体在出膜前期(43 h)停止发育。(3)各组胚胎发育形态上的差别主要表现在杂交二倍体未形成正常胚体,单倍体表现出典型的单倍体综合征,雌核发育二倍体初孵仔鱼在形态学上与普通二倍体无明显差异。该研究为兰州鲇雌核发育技术提供了技术支撑,同时也为单倍体、杂交和雌核发育胚胎的细胞生物学研究提供了理论依据。     

异源四倍体鲫鲤、三倍体湘云鲫和它们父母本线粒体DNA 12S rRNA基因遗传变异的分析

采用质粒克隆测序方法,获得了异源四倍体鲫鲤5个个体、异源四倍体鲫鲤雌核发育二倍体后代2个个体、三倍体湘云鲫2个个体及红鲫、湘江野鲤和日本白鲫各1个个体的线粒体DNA 12S rRNA基因的全序列。经对比发现,异源四倍体5个个体共享2种单元型,异源四倍体鲫鲤雌核发育二倍体后代2个个体、三倍体湘云鲫2个个体以及红鲫、湘江野鲤和日本白鲫各1个个体分别共享1种单元型。用MEGA 1.0 软件分析了它们的碱基组成和核苷酸序列差异,用邻接法构建系统进化树。它们间的序列同源性在95%~99%之间,异源四倍体鲫鲤、三倍体湘云鲫和它们母本（分别为红鲫和日本白鲫）之间的序列同源性大于异源四倍体鲫鲤、三倍体湘云鲫和它们父本（分别为湘江野鲤和异源四倍体鲫鲤）之间的序列同源性,结果表明：异源四倍体鲫鲤和三倍体湘云鲫在线粒体DNA 12S rRNA基因上具有母性遗传特征。本研究另一值得注意地方的是异源四倍体鲫鲤经过9代(F3-F11)繁殖后,在5个个体中发现了2种单元型,说明在四倍体基因库中存在遗传多样性,为四倍体基因库的繁殖、保护和种群复壮提供了一些有价值的信息。     

人工诱导泥鳅雌核发育的细胞学研究和诱导参数优化

为培育泥鳅(Misgurnus anguillicaudatus)全雌品种,研究通过细胞荧光染色后进行细胞学观察确定人工诱导泥鳅雌核发育的热休克起始时间,并进一步利用核型和流式细胞分析等方法对人工诱导雌核发育泥鳅进行鉴定。结果显示,二倍体泥鳅受到灭活的鲤(Cyprinus carpio)精子刺激后,第二极体与卵核分开的时间在人工授精后3—5min;卵子在人工授精后3.5min后再热休克2min的诱导孵化率达到10.26%。通过分析野生型泥鳅胚胎、人工诱导雌核发育泥鳅胚胎、泥鳅×鲤杂交胚胎和单倍体泥鳅胚胎的发育,发现部分雌核发育的胚胎可以正常发育,而杂交胚胎和单倍体胚胎会出现明显的发育障碍。核型和流式细胞检测分析表明利用本研究获得的热休克参数进行处理可得到二倍体雌核发育子代,二倍率达64.71%。研究从细胞学层面获得泥鳅雌核发育的诱导参数,可为利用人工诱导雌核发育开展全雌泥鳅育种提供指导。     

远缘杂交导致不同倍性鱼的形成

远缘杂交可以使基因组从一个物种转移到另一个物种中,从而导致杂交后代的表现型和基因型都发生改变.本文描述了在红鲫(♀)与鲤鱼(♂)的远缘杂交后代中,形成了F3~F18两性可育异源四倍体鲫鲤群体(4n=200,简称为4nAT).4nAT的雌、雄个体分别产生的二倍体卵子和二倍体精子,经过雌核发育和雄核发育,在没有染色体加倍处理情况下,分别发育成雌核发育二倍体后代和雄核发育二倍体后代.其中雌核发育体系衍生出具有遗传变异的改良四倍体鲫鲤和改良二倍体鱼,二倍体杂交鱼产生不减数的配子的现象与减数分裂前核内复制或者核内有丝分裂或者生殖细胞融合有关.用雄性4nAT与雌性二倍体鱼进行倍间交配大规模制备了不育三倍体鱼.在红鲫(♀)与团头鲂(♂)的远缘杂交后代中,成功地获得两性可育的天然雌核发育红鲫(2n=100),不育的三倍体鲫鲂(3n=124)以及两性可育的四倍体鲫鲂(4n=148),此外,还制备了两种五倍体鲫鲂(5n=172;5n=198).该文在细胞和分子水平上对不同倍性鱼的生物学特点和形成机制进行了比较,揭示了远缘杂交或者将远缘杂交与雌核发育和雄核发育相结合的方法在具有遗传变异的不同倍性鱼的形成中发挥着积极作用,这在生物进化和鱼类遗传育种方面都具有重要意义.     

不同倍性鱼的血细胞和精子DNA含量比较

我们以前的研究表明, 以红鲫 (2n=100) 为母本及湘江野鲤 (2n=100) 为父本的杂交后代的F1-F2 为二倍体 (2n= 100)。在二倍体 F2 个体中, 存在能分别产生二倍体卵子和二倍体精子的雌、雄个体, 二倍体卵子和二倍体精子结合, 形成了两性可育的四倍体鱼 (F3)。目前四倍体鲫鲤已连续繁殖了 12 代 (F3-F14), 形成了一个遗传性状稳定的四倍体鱼群体 (4n= 200) (Liu et al.,2001; 孙远东等, 2003)。雌性四倍体鲫鲤产生的二倍体卵子经紫外线照射的散鳞镜鲤精子激活后,无须染色体加倍处理, 可发育为全雌性二倍体雌核发育后代 (G1) (2n=10…     

湖南师范大学鱼类发育学研究室最新研究成果展示

湖南师范大学鱼类发育生物学研究室在成功研制了四倍体鲫鲤群体(F3-F18)的基础上,利用四倍体鲫鲤群体产生的二倍体卵子本身具有2套染色体组的特点,通过雌核发育技术,在没有染色体加倍处理情况下,经灭活的散鳞镜鲤精子刺激,建立了一个能大量产生二倍体卵子的雌核发育二倍体克隆体系(G1-G5)。有关该研究     

MAPK在不同生殖特性鲫鲤杂交鱼性腺组织中的表达分析

运用Western-blot技术和免疫组织化学来检测丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPKs)家族成员细胞外调节蛋白激酶(extracellular regulated protein kinase,ERK)和c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)在不同生殖特性鲫鲤杂交鱼性腺组织中的表达。研究表明,JNK、ERK在鱼类性腺组织中均有较高量的表达,但在鱼类卵巢和精巢间、雌核发育二倍体鲫鲤和不同倍性鱼的性腺组织间,JNK或ERK的表达量并不存在明显的差异,而P-JNK在雌核发育二倍体鲫鲤性腺中的表达量远高于三倍体和四倍体鲫鲤的卵巢组织。此外,JNK和ERK在雌核发育二倍体鲫鲤早期性腺性原细胞中均有阳性表达。其中,JNK在10月龄雌核发育二倍体鲫鲤性腺中的阳性反应强度高于6、8月龄;而ERK在8月龄和10月龄的性腺中的阳性反应则弱于6月龄。结果表明JNK通路可能对雌核发育二倍体鲫鲤产生不减数配子具有重要调控作用。     

用雄核发育方法制备改良异源四倍体鲫鲤群体

用UV照射金鱼的卵子使其卵核的遗传物质失活, 再与异源四倍体鲫鲤(AT)产生的二倍体精子受精, 在无雄核染色体加倍处理情况下, 成功地获得了两性可育的二倍体雄核发育鱼(A₀). Ⅱ龄性成熟的A₀自交形成了雄核发育鱼自交子一代(A₁). 本研究对10月龄A₁的染色体数目、性腺的显微和亚显微结构以及外型特征进行了观察, 实验结果表明: (ⅰ) A₁中包含有四倍体(A₁-4n)、三倍体(A₁-3n)以及二倍体后代(A₁-2n), 他们所占比例分别为85%, 10%和5%, 其染色体数目分别为4n=200, 3n=150和2n=100. 其中四倍体和三倍体的形成证明二倍体A₀能产生二倍体配子. 二倍体雄核发育鲫鲤杂交鱼产生二倍体配子的原因与早期生殖细胞的核内复制机制有关. (ⅱ) A₁-4n的性腺为两性型且发育正常. 其中雄性个体能挤出白色精液, 其中的二倍体精子头部明显比红鲫的单倍体精子头部大. 这些二倍体精子具有正常结构, 由头部和尾部组成, 头部与尾部交接处有多个线粒体, 精子尾巴的中央轴有典型的“9+2”微管结构. A₁-4n雌性个体的卵巢发育饱满, 其中含有大量Ⅱ, Ⅲ和Ⅳ时相的卵母细胞. 在Ⅳ时相卵母细胞的放射膜上能观察到受精孔. 同时期的A₁-2n, A₁-3n的性腺发育异常, 均表现为不育. A₁-2n的不育性与其为远源杂交二倍体有关, A₁-3n的不育性与其为远源杂交三倍体有关. (ⅲ) 与AT相比, A₁-4n不仅具有生长速度快、抗逆性强的优点, 而且在外型上具有体背高、尾柄短、头部小等优良性状. 本实验说明运用雄核发育技术不仅能获得两性可育的四倍体鱼, 而且能对异源四倍体鲫鲤进行有效的遗传改良, 这在细胞遗传研究和鱼类育种方面都具有重要意义.     

Induction of Gynogenesis in Japanese Crucian Carp (Carassius cuvieri)

Diploid gynogenesis was induced in Japanese crucian carp (Carassius cuvieri) eggs using UV-irradiated genetically inactive spermatozoa from mirror carp (Cyprinus carpio L.) or blunt snout bream (Megalobrama amblycephala), with or without cold shock. The optimal radiation dosage was 4200 mJ/cm² and 3600 mJ/cm² for mirror carp and blunt snout bream sperm, respectively. At this dosage and without cold shock, the yields were (32.4±3.3)% vs. (33.8±1.4)% gynogenetic haploids and (0.7±0.3)% vs. (0.5±0.3)% hybrid diploids, respectively. At the optimal UV dosage but with cold shock (2 min after fertilization, 0-4°C for 40 min), the hatching rates were (27.8±2.1)% and (29.4±3.3)%, respectively. From hatching to feeding, (15.7±3.4)% and (23.6±4.1)% normal gynogenetic diploids were recorded, respectively. Survival of normal gynogenetic diploids was 56% out of the hatched fry when using irradiated spermatozoa of mirror carp, which was lower than that (up to 80%) when using irradiated spermatozoa of blunt snout bream. This indicated that the sperm of blunt snout bream, with distant genetic relation to the maternal Japanese crucian carp, was more effective than that of mirror carp to induce diploid gynogenesis. The nature of the gynogenetic progeny was identified with external appearance, chromosome number and gonad structure. The presence of only females in gynogenetic progeny probably suggested XX genotype in the female Japanese crucian carp. The gynogenetic diploids have potential values such as faster growth and stronger disease resistance than the normal Japanese crucian carp. All gynogenetic progeny possessed 100 chromosomes whereas all J x B crosses were triploid with 124 chromosomes. The formation of the new triploid hybrids in J x B crosses may be useful in aquaculture.     

四类不同倍性鲫鱼在胚胎发育期间同工酶基因表达的比较分析

Isozyme zymograms of esterase (EST), lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and superoxide dismutase (SOD) were analysed by polyacrylamide gradient gel electrophoresis at different developmental stages of embryogenesis in 4 types of various ploidy crucian carp embryos, including haploids, diploids, natural triploids, and multiple tetraploids, and 2 types of haploid and diploid common carp embryos. Haploid embryos of crucian carp (Carassius auratus) and common carp (Cyprinus carpio) were produced by treating eggs with UV-irradiated milt from blunt snout bream (Megalobrama amblycephala). Natural triploid embryos were obtained from the eggs of gynogenetic silver crucian carp (Carassius auratus gibelio) inseminated with milt from red common carp. Multiple tetraploid embryos were also produced by gynogenesis from eggs of the newly discovered multiple tetraploid females inseminated with milt from red common carp. Gradient gel electrophoresis indicated that the band types and staining intensity of 4 isozymes expressed in haploid embryos of crucian carp and red common carp were similar to that in the correlative diploid embryos. In natural triploid silver crucian carp embryos, the zymograms of MDH and SOD isozymes were identical with that of diploid crucian carp embryos, but the EST and LDH isozymes manifested more new enzyme bands in comparison with diploid embryos. The corresponding expressed products of some bands in the triploid embryos, such as EST5 and EST6, could be observed also in red common carp embryos, which provided evidence for hybrid origin about the gynogenetic fish. The multiple tetraploids incorporated one foreign genome of red common carp, therefore, the effects of genes from the foreign genome could be observed in the multiple tetraploid embryos. Gene expression of the isozymes in the tetraploid embryos was somewhat similar to that in hybrids. Owing to interaction of triploid silver crucian carp genomes and common carp haploid genome, some isozyme bands, such as EST5 and EST6, changed in quantity, and some bands increased, such as s-SOD1, s-SOD2, s-SOD3 and s-SOD4 in the tetraploid embryos. Moreover, the heterogeneity was revealed among embryos developed from gynogenetic eggs of 3 different multiple tetraploid individuals.     

四类不同倍性鲫鱼在胚胎发育期间同工酶基因表达的比较分析

用聚丙烯酰胺梯度凝胶电泳比较分析了单倍体、二倍体、三倍体和复合四倍体4类不同倍性鲫鱼以及单倍体和二倍体鲤鱼在胚胎发育时期4种同工酶(EST,LDH,MDH,SOD)酶谱。结果表明,单倍体鲫鱼和单倍体鲤鱼胚胎与各自的二倍体胚胎相比,同工酶酶谱看不出差异;天然三倍体银鲫胚胎的MDH和SOD同工酶酶谱与二倍体鲫相似,但EST和LDH同工酶比二倍体增多了酶带,有的酶带如EST5和EST6还可在鲤鱼胚胎中找到相应的表达产物,提供了天然雌核发育三倍体银鲫杂交起源的证据;复合四倍体由于含有鲤鱼的一个外来基因组,其胚胎的基因表达有些与杂种类似,在所分析的4种同工酶酶谱中,都可观察到来自鲤鱼基因的影响。此外,在由源于不同复合四倍体个体的卵子发育形成的胚胎间,还观察到同工酶基因表达的异质性。     

草鱼雌核发育后代不同群体的微卫星遗传分析及指纹识别

以紫外线灭活的团头鲂精子激活草鱼卵子,冷休克抑制第二极体排出的方法诱导出长江水系优良F2代草鱼减数雌核发育子代。在后代中不仅存在雌核发育后代,还存在草鲂杂交后代,雌核发育后代的体型与草鱼一致,而草鲂杂交后代的体型介于草鱼与团头鲂之间。Partec CyFlow倍性分析仪测定结果显示:普通草鱼与雌核发育草鱼的相对DNA含量分别为23.01和22.72,二者的DNA含量接近;而高体型子代的相对DNA含量为25.38,介于草鱼与团头鲂（DNA含量28.21）之间,属于草鲂杂交后代。选取17个微卫星标记对草鱼群体、雌核发育草鱼群体和草鲂杂交后代的遗传多样性进行了检测,共检测出59个等位基因,其中43.18个有效等位基因。草鱼对照群体、草鲂杂交后代和雌核发育草鱼群体的平均等位基因依次为3.57、2.86和2.79,平均有效等位基因依次为2.93、2.37和1.96,平均期望杂合度在依次为0.6502、0.5573和0.3775,多态信息含量（PIC）平均值依次为0.5738、0.4649和0.3791。与草鱼对照群体相比,雌核发育草鱼群体的遗传多样性显著下降,表明通过减数雌核发育方法可获得纯合性较高的草鱼个体。构建了草鱼后代不同群体的DNA指纹模式图,筛选到不同群体的9个特异微卫星标记,为草鱼优良群体的选育提供了基础资料。     

Microsatellite analysis of different ploidy offspring of artificial gynogenesis in Cyprinus carpio

Gynogenesis was induced by using UV-irradiated spermatozoa of blunt snout bream Megalobrama amblycephala to activate eggs of common carp Cyprinus carpio. The maternal genome was then duplicated by cold shock in 0 to 4° C cold water to retain the second polar body. Two kinds of fry, normal fry and abnormal tortuous fry, were hatched. Their DNA content was measured by flow cytometry. The normal fry were identified as diploid, representing the successful gynogenesis in C. carpio whereas the abnormal tortuous fry were haploid. Ten microsatellite loci were used to study the genetic diversity among C. carpio, diploid gynogenetic C. carpio and unduplicated haploid tortuous fry. The results indicated that the genetic homozygosity of gynogenetic C. carpio was significantly higher than that of C. carpio. The genetic homozygosity of the haploid C. carpio was intermediate between that of gynogenetic C. carpio and C. carpio. It might be easier for the allogenetic DNA fragments to be integrated into the haploid genome than into diploid gynogenetic genome.     

Massive production of all-female diploids and triploids in the crucian carp

In many species of aquaculture importance, all-female and sterile populations possess superior productivity due to faster growth and a relatively homogenous size of individuals. However, the production of all-female and sterile fish in a large scale for aquaculture is a challenge in practice, because treatments necessary for gynogenesis induction usually cause massive embryonic and larval mortality, and the number of induced gynogens is too small for their direct use in aquaculture. Here we report the massive production of all-female triploid crucian carp by combining artificial gynogenesis, sex reversal and diploid-tetraploid hybridization. Previously, we have obtained an allotetraploid carp population (4n = 200) by hybridization between red crucian carp (Carassius auratus red var; ♀) and common carp (Cyprinus carpio; ♂). We induced all-female diploid gynogens of the Japanese crucian carp (Carassius cuvieri; 2n = 100). We also generated male diploid gynogens of the same species treated gynogenetic fry with 17-α-methyltestosterone, leading to the production of sex-revered gynogenetic males. Finally, these males were used to cross with the female diploid Japanese crucian carp gynogens and the allotetraploid females, resulting in the production of fertile all-female diploid Japanese crucian carp (2n=100) and sterile all-female triploid hybrids (3n = 150), respectively. Therefore, diploid crucian carp gynogenetic females and sex-reversed male together with an allotetraploid line provide an opportunity to produce all-female triploid populations in a large scale to meet demands in aquaculture industry.     

异源精子在银鲫雌核发育子代中的生物学效应

黑龙江省方正县双凤水库的两性型银鲫群体是三倍体雌核发育种群。异源精子不仅能刺激银鲫卵雌核发育,而且还能影响雌核发育子代的某些性状,如对于子代的生长、性比、体色和肝脏LDH同工酶等都产生了影响。为区别于原有术语“雌核发育gynogenesis”,我们把这种表现了异源精子生物学效应的雌核发育称之为“异精雌核发育allogynogenesis”,发育的子代称之为“异育银鲫”。异育银鲫已以其明显的生长优势在生产上显示了优良的经济性状。       

Evidence for the Formation of the Male Gynogenetic Fish

The females and unexpected males of gynogenetic red crucian carps (GRCC) with the 1:1 sex ratio were found in the progeny of the distant crossing of red crucian carp (RCC; ♀, 2n?=?100) × blunt snout bream (BSB; ♂, 2n?=?48). The females and males of GRCC were fertile, and they mated each other to generate the red crucian carps (GRCC₁) and another variational gray crucian carps (GGCC). The GRCC and their offspring were proved to be diploids (2n?=?100) with one to three microchromosomes by examining the chromosomal metaphases. The evidences for the male’s genetic effect in GRCC were provided by means of fluorescence in situ hybridization, Sox-HMG DNA markers, and microsatellite DNA markers. The genotypic variances of GRCC resulted in their phenotypic variances which were quite different from their maternal parent. It was concluded that the formation of the male gynogenetic fish in GRCC resulted from the genetic leakage of the paternal fish in the form of the microchromosomes including the paternal male-determining gene. After being activated by the sperm of BSB, which was inactivated and finally degraded but left the microchromosomes, the egg of RCC, in which the 50 chromosomes were spontaneously doubled to 100 chromosomes, developed into the diploid male gynogenetic fish. The formation of the bisexual GRCC and their progeny indicated that the distant hybridization could generate the bisexual diploid gynogenetic fish with genetic variation derived from the paternal fish, which is of great significance in both fish genetic breeding and evolutionary biology.     

Fertility of triploid hybrids of Prussian carp (<Emphasis Type="Italic">Carassius gibelio</Emphasis>) with common carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.)

Fertility of backcross triploid hybrids containing one genome of Prussian carp and two genomes of common carp is investigated. The females of hybrids of Prussian carp and common carp (Prussian × common carp) are prolific and produce diploid gametes. Since males of such hybrids are sterile, their reproduction is realized by means of induced gynogenesis. Triploid progeny is obtained by backcrossing female Prussian × common carp with carp males. Among triploids obtained from hybrids F₁ and among hybrids of the first gynogenetic generation, there were no prolific specimens. However, in reproduction of diploid hybrids by means of gynogenesis during six generations, the female fertility in the backcross progeny is restored. From backcross triploid females (daughters of Prussian × common carp of the sixth gynogenetic generation), a viable triploid gynogenetic progeny and a tetraploid backcross (by carp) progeny are obtained. The obtained data may be considered as the experimental proof of the hypothesis of reticular speciation.     

雌核发育团头鲂的形态和遗传特征分析

利用团头鲂(Megalobrama amblycephala)正常二倍体群体作为对照组, 对团头鲂减数分裂雌核发育二倍体群体的形态特征、染色体组型、性腺发育及遗传特征进行了分析. 结果表明: 雌核发育群体与正常群体在外部可数、可量性状上没有显著性差异(P0.05); 但雌核发育群体出现了尾鳍条数为12的畸形个体, 与正常个体之间有较大的差异; 两个群体的染色体条数都是48, 核型均为18 m+26 sm+4 st; 观察了20尾雌核发育个体的性腺, 均为雌性个体且卵巢发育良好; 采用10个微卫星标记对2个群体的遗传多样性分析, 结果表明正常群体和雌核发育群体平均等位基因数分别为3.8个和1.7个, 雌核发育群体的多态性显著低于正常群体, 表明减数分裂雌核发育二倍体具有高度的遗传相似性, 可作为一个很好的育种材料.