Genetic diversity and the biogeographical process of Acheilognathus macropterus revealed by sequence variations of mitochondrial cytochrome b gene
Genetic diversity and the biogeographical process of Acheilognathus macropterus revealed by sequence variations of mitochondrial cytochrome b gene
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DOI：
10.1007/s11515-007-0069-4
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Yurong Zhu;Huanzhang Liu
中科院分区：
文献类型：
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作者：
Yurong Zhu;Huanzhang Liu
本研究从黑龙江、长江、南渡江采集了36头长尾鮈个体。对这些样本的部分线粒体细胞色素b基因区域（636个碱基对）进行了测序，发现了22个单倍型。与A. chankaensisandA. tokinensisas 外群，分析了它们的关系。使用Mega软件计算Thep距离，并使用邻接（NJ）方法构建分子系统发育树。并比较了主要形态性状的比例。P距离显示A．巨翼龙样本远小于这些样本和外群之间的样本。分子系统发育树显示，有触须的样本和没有触须的样本混合在一起。各形态特征比例无显着差异。这些结果表明，有触须的样本和没有触须的样本（正式鉴定为A. taenianalis）是同一物种；A. taenianalisis 与A同义。大翼龙。这 36 个个体被分为 5 个分支，并且样本在分支中的位置在其地理分布内相应地分组。 5个支系中，支系1和支系5分别包含来自黑龙江和南渡江的样本。长江流域样本分散为2、3、4类，其间存在显着的遗传差异（>5%）。有趣的是，这三个进化枝中的 21 个样本的分布与其地理分布无关。据推测，这些遗传差异是由于苦鱼的交配选择机制（即合子隔离）造成的。南渡江鱼类与大陆鱼类的基因差异表明它们很早就分离了。然而，样本之间微小的遗传差异以及黑龙江鱼类在分子系统发育树中的位置表明，黑龙江鱼类可能很晚才从长江扩散到该地区。
In this study, thirty-six individuals ofAcheilognathus macropteruswere collected from the Heilongjiang River, the Yangtze River, and the Nandujiang River. Partial mitochondrial cytochromebgene region (636 base pair) was sequenced to these samples and 22 haplotypes were found. WithA. chankaensisandA. tokinensisas outgroups, their relationships were analyzed. Thep-distances were calculated with Mega software and a molecular phylogenetic tree was constructed using the neighbor-joining (NJ) method. The proportions of main morphological characters were compared as well.P-distances showed that the genetic differences inA. macropterussamples were far smaller than those between these samples and the outgroups. The molecular phylogenetic tree shows that samples with barbels and those without barbels were intermingled. There was no distinctive difference in proportions of morphological characteristics among them. These results suggested that samples with barbels and those without barbels (formally identified asA. taenianalis) are the same species;A. taenianalisis synonymous withA. macropterus. The thirtysix individuals were grouped into five clades and the positions of the samples in the clades were correspondingly grouped within their geographical distributions. Among the five clades, clades 1 and 5 included samples from the Heilongjiang River and Nandujiang River respectively. The samples from the Yangtze River scattered into clades 2, 3, and 4. There were distinctive genetic differences (>5%) among them. Interestingly, the distributions of the 21 samples in these three clades were not correlated to their geographical distributions. It is postulated that these genetic differences were due to the bitterlings’ mating choice mechanism, the prozygotic isolation. The genetic differences between the fish from Nandujiang River and those from the mainland indicated that they were separated early. However, the small genetic differences among the samples and the positions of the fish from the Heilonjiang River in the molecular phylogenetic tree indicate that fish in Heilongjiang River might have dispersed from the Yangtze River to that area much later.