Analysis of three multigene families as useful tools in species characterization of two closely-related species, Dicentrarchus labrax, Dicentrarchus punctatus and their hybrids
Analysis of three multigene families as useful tools in species characterization of two closely-related species, Dicentrarchus labrax, Dicentrarchus punctatus and their hybrids
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DOI：
10.1266/ggs.85.341
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发表时间：
2010-10-01
影响因子：
1.1
通讯作者：
Rebordinos, Laureana
中科院分区：
文献类型：
--
作者：
Alejandro Merlo, Manuel;Cross, Ismael;Rebordinos, Laureana
通过对3个多基因家族的分析，利用细胞遗传学和分子生物学方法，对两个亲缘关系密切且具有重要商业价值的物种--唇形双钩线虫和斑点双圆线虫进行了特征分析。此外，还分析了种间杂交种间的唇形双柄线虫(雌性)、斑点双柄线虫(雄性)。所研究的多基因家族有5S rDNA、45S rDNA和U2单链RNA。在两个物种的5S rDNA的非转录间隔区(NTS)中发现了一个微卫星GTT基序。然而，在唇形虫和杂交克隆中观察到该微卫星旁边的六核苷酸重复，而在斑点纹饰鱼中未观察到。U2单链RNA似乎与U5基因连锁，并显示出两个变异序列，分别存在于唇形吸虫和斑点吸虫中。它们的不同之处在于一个7个核苷酸的插入/缺失。斑点杜鹃的第一内转录间隔区(ITS-1)的核苷酸变异性比唇形杜鹃高。在不同的基因区域确定了物种内的核苷酸多态和物种间的核苷酸差异。在FISH分析中，我们获得了三个染色体标记，因为5S rDNA、18S rDNA和U2 SnRNA探针分别在三个不同的染色体对中杂交。因此，它们都不是共同本地化的。5S rDNA簇和U2 SnRNA定位于端着丝粒染色体对，而18S rRNA基因探针杂交于近端着丝粒染色体对。最后，结合其他鱼类物种，讨论了这些结果在开发系统发育分析和物种鉴定工具方面的有用性。
By analyzing three multigene families, two closely related and commercially important species, Dicentrarchus labrax and Dicentrarchus punctatus, were characterized by cytogenetic and molecular methods. The interspecies hybrid Dicentrarchus labrax (female) Dicentrarchus punctatus (male) was also analyzed. The multigene families studied were the 5S rDNA, 45S rDNA and the U2 snRNA. A microsatellite GTT motif was found within the non transcribed spacers (NTS) of the 5S rDNA from the two species. However, hexanucleotide duplication next to this microsatellite was observed in the D. labrax and hybrid clones, but not in D. punctatus. The U2 snRNA appeared to be linked to the U5 gene and showed two variant sequences, in both D. labrax and D. punctatus. They differed in one insertion/deletion of 7 nucleotides. The first internal transcribed spacer (ITS-1) region showed higher nucleotide variability in D. punctatus than in D. labrax. Nucleotide polymorphism within species and also nucleotide divergence between species were determined in the different gene regions. In a FISH analysis we obtained three chromosomal markers, because the 5S rDNA, 18S rDNA and U2 snRNA probes hybridized each in three different chromosome pairs. Hence none of them was co-localized. The 5S rDNA cluster and U2 snRNA were localized in acrocentric chromosome pairs, while the 18S rRNA gene probe hybridized in a subtelocentric pair. Finally, the usefulness of the results in developing tools for phylogenetic analysis and species identification are discussed in relation to other fish species.