The formation of the polyploid hybrids from different subfamily fish crossings and its evolutionary significance
The formation of the polyploid hybrids from different subfamily fish crossings and its evolutionary significance
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DOI：
10.1534/genetics.107.071373
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发表时间：
2007-06-01
期刊：
影响因子：
3.3
通讯作者：
Liu, Yun
中科院分区：
文献类型：
--
作者：
Liu, Shaojun;Qin, Qinbo;Liu, Yun
本研究从染色体、DNA含量、DNA片段和序列以及形态学水平为红鲫与团头鲂多倍体杂种的成功建立提供了遗传学依据。本研究成功地获得了红鲫（RCC）（雌）×团头鲂（BSB）（雄）的不育三倍体和两性可育四倍体及其五倍体杂种。三倍体杂种有124条染色体，其中2条来自RCC，1条来自BSB;四倍体杂种有148条染色体，其中2条来自RCC，2条来自BSB。四倍体杂种的雌性产生未减数的四倍体卵子，其与BSB的单倍体精子受精以产生具有172条染色体的五倍体杂种，其中三组来自BSB，两组来自RCC。通过染色体计数、核型分析、DNA含量和红细胞核体积的测定，确定了三倍体、四倍体和五倍体杂种的倍性水平。对三倍体、四倍体杂种及其亲本的相似和不同DNA片段进行PCR扩增和测序，以揭示它们的分子遗传关系和遗传标记。此外，本研究还对多倍体杂种的表型和食性进行了研究，并对多倍体杂种的形成机理进行了探讨。这是首次在脊椎动物中通过不同染色体数目的亲本杂交形成三倍体、四倍体和五倍体杂种。多倍体杂种的形成在进化和鱼类遗传育种方面都具有潜在的意义。
This study provides genetic evidences at the chromosome, DNA content, DNA fragment and sequence, and morphological levels to support the successful establishment of the polyploid hybrids of red crucian carp X blunt snout bream, which belonged to a different subfamily of fish (Cyprininae subfamily and Cultrinae subfamily) in the catalog. We successfully obtained the sterile triploid hybrids and bisexual fertile tetraploid hybrids of red crucian carp (RCC) (female) X blunt snout bream (BSB) (male) as well as their pentaploid hybrids. The triploid hybrids possessed 124 chromosomes with two sets from RCC and one set from BSB; the tetraploid hybrids had 148 chromosomes with two sets from RCC and two sets from BSB. The females of tetraploid hybrids produced unreduced tetraploid eggs that were fertilized with the haploid sperm of BSB to generate pentaploid hybrids with 172 chromosomes with three sets from BSB and two sets from RCC. The ploidy levels of triploid, tetraploid, and pentaploid hybrids were confirmed by counting chromosomal number, forming chromosomal karyotype, and measuring DNA content and erythrocyte nuclear volume. The similar and different DNA fragments were PCR amplified and sequenced in triploid, tetraploid hybrids, and their parents, indicating their molecular genetic relationship and genetic markers. In addition, this study also presents results about the phenotypes and feeding habits of polyploid hybrids and discusses the formation mechanism of the polyploid hybrids. It is the first report on the formation of the triploid, tetraploid, and pentaploid hybrids by crossing parents, with a different chromosome number in vertebrates. The formation of the polyploid hybrids is potentially interesting in both evolution and fish genetic breeding.