Assessing the genetic diversity in Argopecten nucleus (Bivalvia: Pectinidae), a functional hermaphrodite species with extremely low population density and self-fertilization: Effect of null alleles
Assessing the genetic diversity in Argopecten nucleus (Bivalvia: Pectinidae), a functional hermaphrodite species with extremely low population density and self-fertilization: Effect of null alleles
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DOI：
10.1002/ece3.6080
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发表时间：
2020-04-02
影响因子：
2.6
通讯作者：
Adriana Velasco, Luz
中科院分区：
文献类型：
--
作者：
Barros, Judith;Winkler, Federico M.;Adriana Velasco, Luz
扇贝核是一种具有自花受精功能的雌雄同体的栉孔扇贝，其自然种群密度通常很低。在本研究中，从Neguanje湾，圣玛尔塔（哥伦比亚）的野生种群的遗传多样性，估计使用微卫星标记，和无效等位基因的存在对这一估计的影响进行了评估。共开发了8个微卫星标记，首次描述了该物种，并标准化了它们的扩增条件。它们被用来确定48个野生个体的基因型，从Naguanje湾，和1,010个个体来自38个定向杂交的后代。对于每个基因座，使用统计软件包Micro-Risk估计鉴定的等位基因（包括无效等位基因）的频率，并使用分离分析确认亲本基因型。每个位点检测到3 ~ 8个等位基因，频率为0.001 ~ 0.632。无效等位基因频率范围为0.10 - 0.45，Ho为0.0 - 0.79，He为0.53 - 0.80。所有位点均处于H-W不平衡状态。无效等位基因频率值较高，使用分离分析的估计值低于使用Micro-PCR的估计值。结果表明，该群体具有较高的遗传多样性，无效等位基因不是导致所有位点偏离H-W平衡的唯一原因，表明该群体存在近交和Wahlund效应。
Argopecten nucleus is a functional hermaphroditic pectinid species that exhibits self-fertilization, whose natural populations have usually very low densities. In the present study, the genetic diversity of a wild population from Neguanje Bay, Santa Marta (Colombia), was estimated using microsatellite markers, and the effect of the presence of null alleles on this estimation was assessed. A total of 8 microsatellite markers were developed, the first described for this species, and their amplification conditions were standardized. They were used to determine the genotype of 48 wild individuals from Naguanje Bay, and 1,010 individuals derived from the offspring of 38 directed crosses. For each locus, the frequencies of the identified alleles, including null alleles, were estimated using the statistical package Micro-Checker, and the parental genotypes were confirmed using segregation analysis. Three to 8 alleles per locus with frequencies from 0.001 to 0.632 were detected. The frequencies of null alleles ranged from 0.10 to 0.45, with Ho from 0.0 to 0.79, and He from 0.53 to 0.80. All loci were in H-W disequilibrium. The null allele frequencies values were high, with lower estimations using segregation analysis than estimated using Micro-Checker. The present results show high levels of population genetic diversity and indicate that null alleles were not the only cause of deviation from H-W equilibrium in all loci, suggesting that the wild population under study presents signs of inbreeding and Wahlund effect.