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三个三倍体鲫鱼品系及野鲫mtDNA的比较研究 总被引:32,自引:2,他引:30
用16种限制性内切酶研究了银鲫(3N=156~162)、彭泽鲫(3N=162)和缩骨鲫(3N=150)3个三倍体鲫鱼品系及野鲫(2N=100)的线粒体DNA。有6种酶在种系间和种系内产生限制性片段长度多态性(RFLPs),银鲫共存在4种单倍型,彭泽鲫2种,野鲫3种,缩骨鲫1种。彭泽鲫和银鲫拥有相同的常见单倍型,缩骨鲫的单倍型属于野鲫的常见型。根据限制性位点的变异数据,计算了单倍型间的相似性、核苷酸多样性、品系内核苷酸多样性和品系间的遗传距离,确定彭泽鲫属于银鲫的一个地方品系,缩骨鲫属于野鲫的一个地方品系。根据核苷酸的差异,推算出银鲫和野鲫两个亚种的分化大约在11万年前完成。 相似文献
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由鲤(Cyprinus carpio)和鲫(Carassius auratus)染色体组叠加构建的 两个单性人工多倍体克隆 总被引:5,自引:0,他引:5
具有天然雌核发育的多倍体杂种鱼可防止杂种优势的分离并保持其后代的杂种优势. 由于假设诱发的多倍体鱼类的生殖模式是天然雌核发育的, 我们进行了鲤鲫杂种的多倍体诱发, 目的是描述经染色体组叠加由有性鲤鲫二倍体转化为异源三倍体及异源四倍体克隆谱系. 鲤鲫杂种产生未减数而具有两亲本染色体组杂种卵子, 未减数的雌核可与入卵的雄核融合叠加形成三倍体合子. 鲤鲫异源三倍体胚胎发育正常, 部分异源三倍体雌性个体可产生未减数的、仍保留母本的三套染色体的成熟卵子. 绝大部分鲤鲫异源人工三倍体个体的成熟卵子的雌核不与入卵的雄核融合, 具有天然雌核发育特性. 异源三倍体卵子在入卵精子的激动下由雌核发育产生全雌后代, 并形成一个单性克隆系, 后代保留异源三倍体母本的形态特征, 并靠雌核发育的生殖方式形成异源三倍体克隆系. 极少数异源三倍体个体的成熟卵子的雌核可与入卵的雄核融合, 再通过染色体组叠加形成鲤鲫异源四倍体. 所有异源四倍体的雌性产生未减数的、含有4个染色体组的成熟卵子. 异源四倍体的成熟卵子保持雌核发育特性, 在近类的精子诱发下产生单性后代, 形成一个异源四倍体单性克隆. 相似文献
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A polyploid hybrid fish with natural gynogenesis can prevent segregation and maintain their hybrid vigor in their progenies.
Supposing the reproduction mode of induced polyploid fish being natural gynogenesis, allopolyploid hybrid between common carp
and crucian carp into allopolyploid was performed. The purpose of this paper is to describe a lineage from sexual diploid
carp transforming into allotriploid and allotetraploid unisexual clones by genome addition. The diploid hybrid between common
carp and crucian carp reproduces an unreduced nucleus consisting of two parental genomes. This unreduced female pronucleus
will fuse with male pronucleus and form allotriploid zygote after penetration of related species sperms. Allotriploid embryos
grow normally, and part of female allotriploid can produce unreduced mature ova with three genomes. Mature ova of most allotriploid
females are provided with natural gynogenetic trait and their nuclei do not fuse with any entrance sperm. All female offspring
are produced by gynogenesis of allotriploid egg under activation of penetrating sperms. These offspring maintain morphological
traits of their allotriploid maternal and form an allotetraploid unisexual clone by gynogenetic reproduction mode. However,
female nuclei of rare allotriploid female can fuse with penetrating male pronuclei and result in the appearance of allotetraploid
individuals by means of genome addition. All allotetraploid females can reproduce unreduced mature eggs containing four genomes.
Therefore, mature eggs of allotetraploid maintain gynogenetic trait and allotetraploid unisexual clone is produced under activation
of related species sperms. 相似文献
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为了获取一个可育的、没有遗传分离的、快速生长的养殖品系,我们通过人工方法诱导了人工复合三倍体鲤鱼。它含有两套鲤鱼(一套是散鳞镜鲤、一套是兴国红鲤)和一套鲫鱼(红鲫)共三套完整的染色体组。在这种复合三倍体中,发现有些受精卵具有罕见于硬骨鱼类中的受精生物学现象,即多精受精。这是一个非常有趣的生物学现象。为了了解其潜在的机制,我们以普通红鲤作为父本、经过干法授精,通过扫描电子显微镜对其受精的早期过程进行了超微结构研究,并以普通二倍体鲤鱼受精的早期过程作为对照。(1)通过对三次产卵季节收集的近1000余粒未受精的成熟人工复合三倍体卵细胞进行观察,发现:每个成熟卵子在其动物极上只有一个敞开的受精孔。它由前庭和精孔管组成。前庭对外开口的平均半径为10~12微米。精孔管的外孔径为3.00~3.50微米(Fig.A&B),只比精子头部直径(2.80~3.00微米)稍大一点。排除了人工复合三倍体鲤鱼成熟卵细胞一次允许两个精子并排进入的可能性。(2)人工复合三倍体鲤鱼在受精后约15~30秒,可以看见大量精子聚集在受精孔的前庭区域(Fig.C)。而在卵子表面的其它区域,没有发现有精子附着的现象。表明:在受精孔的前庭区域有一些吸引 相似文献
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The application of hybrid vigor and crossbreeding is conventional and proved effective. Nevertheless, the phenotype of the progeny of hybrids, which carry hybrid vigor and produce their offspring through bisexual reproduction, will segregate inevitably and their hybrid vigor will de-crease in subsequent generations. The more serious consequence might result in destroying com-pletely those endemic populations when hybrids are released into open water bodies, because hy-brids will cross with the… 相似文献
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