异源四倍体鲫鲤雌核发育后代的RAPD分析

RAPD ANALYSIS OF DIPLOID GYNOGEN POPULATIONS OF ALLOTETRAPLOID HYBRIDS OF RED CRUCIAN CARP(♀) X COMMON CARP(♂)

  • 摘要: 在优化RAPD(随机扩增多态性DNA)检测条件基础上,从134个随机引物中筛选出53个扩增较好且多态性强的引物,对异源四倍体鲫鲤第1代(G1)、第2代(G2)人工诱导的雌核发育二倍体后代群体的DNA多态性及分子标记进行了分析。结果显示,53个随机引物在G1群体和G2群体中检测到的位点数分别为541、511,其中多态性位点数分别为70、52,多态位点比例分别为12.94%、10.18%。两个群体的平均遗传距离分别为0.0732、0.0464。研究表明,经过连续2代人工雌核发育,G2的遗传多样性明显减少,种质进一步纯化。还从53个随机引物的扩增谱带中找到了2个引物(S50、S223)的特异扩增谱带,可以作为第1、2代雌核发育群体间的分子遗传标记。由计算机软件程序构建的分支系统树清晰地反映了两个雌核发育群体及其个体间的相互关系。

     

    Abstract: Following activation by scatter scale carp sperm(a variety of common carp) that were UV-irradiated for 30 min, the diploid eggs stripped from F10female allotetraploid hybrids of red crucian carp(Carassius auratus red var.,♀) X common carp(Cyprinus carpio L.,♂), without or with the cold shock at0-4℃ for 30min, developed in normal live first generation diploidgynogens(G1).Interestingly, like the diploid F2hybrids, these diploid gynogens(G1) also produced diploid eggs. Without the treatment for doubling the chromosome number, the diploid eggs produced by the first generation gynogens, developed into the second-generation gynogens(G2) subjecting to activation by UV-irradiated scatter scale carp sperm. In the present paper, genetic heterogeneity and molecular markers were analyzed by RAPD technique in the first and second generation of artificial induced diploid gynogen population generated by the gynogenesis of F10allotetraploid hybrids. Of one hundred and thirty-four 10-nucleotide-long random primers used in the preliminary analysis, 53 primers produced wel-l amplified and reproducible band patterns.They were selected and used in the further analysis.The number of loci detected in the firs-t generation gynogen population and second-generation gynogen population were 541、 511, and the number of polymorphic loci were 70、 52, respectively.The percentage of polymorphic loci(12.94% )was considerately higher in the G1than that(10.18% ) of G2.The average genetic distances estimated byLynchp s index were 0.0732、 0.0464, respectively.Theresults showed that the genetic diversity of G2was significantly decreased after two continued generation gynogenesis, and the genetic purity of G2 was considerately higher than that of G1.Two primers, such sa S50、 S223, were observed to produce specific bands, and these bands could beused as molecularmarkers for discriminating the firs-t generation diploid gynogens fromthe second-generation diploid gynogens.A phylogenetictree which was constructed using Statistical Analysis System computer programme based on genetic distances clearly revealed that all individuals in the first generation gynogen population were clustered into one group,while all the individuals originated from the second-generation gynogen population were joined into another group.

     

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