Geographical and altitudinal population genetic structure of two dung fly species with contrasting mobility and temperature preference
Geographical and altitudinal population genetic structure of two dung fly species with contrasting mobility and temperature preference
复制标题
DOI：
10.1038/sj.hdy.6800097
复制
发表时间：
2002-08-01
期刊：
影响因子：
3.8
通讯作者：
Blanckenhorn, WU
中科院分区：
文献类型：
--
作者：
Kraushaar, U;Goudet, J;Blanckenhorn, WU
人口的地方适应需要一定程度的时空隔离。以往的研究表明，粪蝇Scathophaga stercoraria和脓毒症cynipsea物种的数量生活史和形态特征的地理和海拔的遗传分化水平低，而不是高度的表型可塑性。这些模式表明，基因流是广泛的，尽管相当大的地理障碍和大的时空变化，在身体大小和相关性状的选择。在这项研究中，我们解决了这一假设，调查的遗传分化的粪蝇种群在整个瑞士的基础上，在每个物种相同的10个电泳位点。总体而言，我们没有发现这两个物种的种群的显着地理分化。这是不一致的较高的基因流率预期由于更好的飞行能力较大的S。粪虫然而，群体内的杂合子缺陷表明结构在更细的规模上，在S的几个基因座中可以看到。cynipsea中的PGM（Phosphoglucomutase）位点;粪虫此外，S. cynipsea在海拔较高的地区表现出更大的基因多样性的趋势，主要由MDH（苹果酸脱氢酶）位点介导，在该位点上第二个等位基因仅存在于海拔1000米以上的种群中。这可能是由于这种暖适应物种在较高海拔处的环境压力增加所致。因此，MDH可能是一个候选位点，在这个物种的热选择，但这仍然是由直接证据证实。In S. Stercoraria，没有发现海拔变化。
Local adaptation of populations requires some degree of spatio-temporal isolation. Previous studies of the two dung fly species Scathophaga stercoraria and Sepsis cynipsea have revealed low levels of geographic and altitudinal genetic differentiation in quantitative life history and morphological traits, but instead high degrees of phenotypic plasticity. These patterns suggest that gene flow is extensive despite considerable geographic barriers and large spatio-temporal variation in selection on body size and related traits. In this study we addressed this hypothesis by investigating genetic differentiation of dung fly populations throughout Switzerland based on the same 10 electrophoretic loci in each species. Overall, we found no significant geographic differentiation of populations for either species. This is inconsistent with the higher rates of gene flow expected due to better flying capacity of the larger S. stercoraria. However, heterozygote deficiencies within populations indicated structuring on a finer scale, seen for several loci in S. cynipsea, and for the locus PGM (Phosphoglucomutase) in S. stercoraria. Additionally, S. cynipsea showed a tendency towards a greater gene diversity at higher altitudes, mediated primarily by the locus MDH (malate dehydrogenase), at which a second allele was only present in populations above 1000 m. This may be caused by increased environmental stress at higher altitudes in this warm-adapted species. MDH might thus be a candidate locus subject to thermal selection in this species, but this remains to be corroborated by direct evidence. In S. stercoraria, no altitudinal variation was found.