Abstract

Natural hybridization of sturgeon species in sympatry area is a relatively frequent but poorly studied phenomenon. A unique picture of asymmetric hybridization for Acipenseridae has developed in the Amur River, the place of inhabitation of two endemic sturgeons of this river basin—Kaluga and Amur sturgeon. Earlier, we showed that the fraction of their hybrids in different years was about 2.5% of the abundance of parent species. All analyzed hybrids carried only one type of mtDNA—Kaluga. However, the identification of hybrids and pure individuals in this study was based on consideration of only external morphological characteristics. In the present work, the set of genetic markers was expanded to include six nuclear loci in the analysis: two introns of the ribosomal protein L8 (RP4L8, RP5L8) and microsatellites An20, Afug41, HLJSX37, and HLJSX350. As a result, it was shown that all morphologically intermediate individuals, previously classified on this basis as hybrids, for each of the nuclear loci had a mixed composition of alleles characteristic of both Kaluga and Amur sturgeon. Among those individuals which by external morphology were identified by collectors as Kaluga, there were identified three individuals that should be classified as hybrids according to their genetic characteristics. In addition, four other individuals were classified as backcrosses to Kaluga. All hybrids and backcrosses had Kaluga mtDNA type, which confirms the earlier conclusion about unidirectional hybridization of Kaluga and Amur sturgeon in nature: Kaluga (♀) × Amur sturgeon (♂). The used set of markers has the necessary resolution and can be recommended for the identification of pure Kaluga and Amur sturgeon and their hybrids. The minimum set of markers for diagnosis includes mtDNA, introns RP4L8 and RP5L8, and microsatellite HLJSX37.

中文翻译：

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根据线粒体和核DNA标记的分析，自然界中的卡卢加州A（Kaluga Acipenser dauricus Georgi，1775年）和阿穆尔St鱼（Amur schrenckii Brandt，1869年）（A）的不对称杂交

摘要

交配区of鱼种类的自然杂交是一个相对频繁但研究较少的现象。阿穆尔河（Amur River）是该流域两个地方性urge鱼（卡卢加和阿穆尔st鱼）的栖息地，这是一个独特的非对称杂交现象。之前，我们显示了不同年份它们的杂种比例约为亲本物种丰富度的2.5％。所有分析的杂种仅携带一种类型的mtDNA-Kaluga。但是，本研究中杂种和纯种个体的鉴定仅基于外部形态特征的考虑。在目前的工作中，遗传标记集被扩展为包括六个核基因座：核糖体蛋白L8的两个内含子（RP4L8，RP5L8）和微卫星An20，Afug41，HLJSX37和HLJSX350。结果表明，先前在此基础上分类为杂种的所有形态学中间个体，对于每个核基因座均具有卡卢加州and和阿穆尔st鱼的等位基因的混合组成。在被收集者鉴定为外部形态的个体中，鉴定出三个个体，根据其遗传特征应将其分类为杂种。此外，另外四个人被归类为卡卢加州的回交。所有杂种和回交都具有卡卢加州mtDNA类型，这证实了关于自然界中卡卢加州和阿穆尔st鱼单向杂交的早期结论：卡卢加州（♀）×阿穆尔st（urge）。所使用的一组标记物具有必要的分辨率，可推荐用于鉴定纯卡卢加州and和阿穆尔st鱼及其杂种。用于诊断的最小标记集包括mtDNA，内含子RP4L8和RP5L8以及微卫星HLJSX37。