Gene flow and population structure in the Mexican blind cavefish complex (Astyanax mexicanus).
Gene flow and population structure in the Mexican blind cavefish complex (Astyanax mexicanus).
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DOI：
10.1186/1471-2148-12-9
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发表时间：
2012-01-23
影响因子：
3.4
通讯作者：
Borowsky RL
中科院分区：
文献类型：
--
作者：
Bradic M;Beerli P;García-de León FJ;Esquivel-Bobadilla S;Borowsky RL
洞穴动物在进化上趋同于一套troglomerorphic特征，其中最著名的是失明和色素脱色。研究了墨西哥Astyanax mexicanus的11个洞穴种群和10个地表种群，以更好地了解洞穴形态的进化起源、洞穴种群和地表种群的基本遗传结构，以及它们之间的现代迁移对遗传分化的影响程度。为了评估群体内的遗传结构和群体间的关系，我们在26个微卫星位点对个体进行了基因分型。我们发现地表种群彼此相似，尽管它们的地理距离相对较大，而洞穴种群则有更好的分化。我们研究的洞穴种群跨越了三个不同地理区域的洞穴形态的全部范围，并且至少有五个不同的进化起源。洞穴种群的遗传多样性低于地面种群，这与它们较小的有效种群规模有关，这可能是食物和空间限制的结果。一些洞穴种群接收来自地表的移民，并相互交换移民，尤其是在地理位置接近的情况下。由于Wahlund效应，这种混合物在许多位点上导致显著的杂合子缺陷。从地表接收移民的洞穴种群包含少量在表型和基因型上都处于中间状态的个体，这至少证实了地表的基因流动是有限的。该物种的洞穴种群来自两种不同的地表种群，分别表示为“旧”和“新”。旧的种群至少独立地在洞穴中殖民了三次，而新的种群至少独立地在洞穴中殖民了两次。因此，在这些洞穴中发现的相似洞穴表型是反复收敛的结果。尽管来自地表种群的基因流动表明，在洞穴环境中，导致洞穴表型的等位基因存在强烈的自然选择或性选择，但这些表型趋同还是发生了。
Cave animals converge evolutionarily on a suite of troglomorphic traits, the best known of which are eyelessness and depigmentation. We studied 11 cave and 10 surface populations of Astyanax mexicanus in order to better understand the evolutionary origins of the cave forms, the basic genetic structuring of both cave and surface populations, and the degree to which present day migration among them affects their genetic divergence. To assess the genetic structure within populations and the relationships among them we genotyped individuals at 26 microsatellite loci. We found that surface populations are similar to one another, despite their relatively large geographic separation, whereas the cave populations are better differentiated. The cave populations we studied span the full range of the cave forms in three separate geographic regions and have at least five separate evolutionary origins. Cave populations had lower genetic diversity than surface populations, correlated with their smaller effective population sizes, probably the result of food and space limitations. Some of the cave populations receive migrants from the surface and exchange migrants with one another, especially when geographically close. This admixture results in significant heterozygote deficiencies at numerous loci due to Wahlund effects. Cave populations receiving migrants from the surface contain small numbers of individuals that are intermediate in both phenotype and genotype, affirming at least limited gene flow from the surface. Cave populations of this species are derived from two different surface stocks denoted "old" and "new." The old stock colonized caves at least three times independently while the new stock colonized caves at least twice independently. Thus, the similar cave phenotypes found in these caves are the result of repeated convergences. These phenotypic convergences have occurred in spite of gene flow from surface populations suggesting either strong natural or sexual selection for alleles responsible for the cave phenotype in the cave environment.
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影响因子：
2.2
作者：
Latch, EK;Dharmarajan, G;Rhodes, OE
通讯作者：
Rhodes, OE
影响因子：
4.1
作者：
Hausdorf, Bernhard;Wilkens, Horst;Strecker, Ulrike
通讯作者：
Strecker, Ulrike
影响因子：
7.7
作者：
Excoffier, Laurent;Lischer, Heidi E. L.
通讯作者：
Lischer, Heidi E. L.
影响因子：
5.8
作者：
Beerli, P
通讯作者：
Beerli, P
DOI：
10.1073/pnas.081068098
发表时间：
2001-04-10
影响因子：
11.1
作者：
Beerli, P;Felsenstein, J
通讯作者：
Felsenstein, J