Asymmetrical sexual isolation but no postmating isolation between the closely related species Drosophila suboccidentalis and Drosophila occidentalis.
Asymmetrical sexual isolation but no postmating isolation between the closely related species Drosophila suboccidentalis and Drosophila occidentalis.
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DOI：
10.1186/s12862-015-0328-y
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发表时间：
2015-03-12
影响因子：
3.4
通讯作者：
Dyer KA
中科院分区：
文献类型：
--
作者：
Arthur NJ;Dyer KA
在物种形成过程中，会出现几种类型的隔离屏障，限制不同种群之间的基因流动。研究最近分离的物种可以让我们了解这些障碍是如何以及何时出现的，以及哪些障碍可能对限制基因流动最重要。在这里，我们重点研究了亚意外果蝇和西方果蝇，这是一种密切相关的蘑菇食性物种，栖息在北美西部，在地理范围上没有重叠。我们研究了这些物种之间的生殖隔离模式，包括交配前、交配后、合子前和合子后对基因流动的障碍。研究人员利用来自单个种群的蝇类，发现这些物种之间的早熟性隔离强度是不对称的：虽然西腹绒棉棉雌蚊与次尾绒棉棉棉雄蚊的交配率较低但中等，但次尾绒棉棉棉雌蚊对与西腹绒棉棉雄蚊的交配有强烈的歧视。雌性杂交种与任何一种雄性的交配率都很高，这表明这种歧视具有隐性遗传基础。两个物种的雌性都接受杂交雄性。我们没有发现交配后合子前或合子后分离障碍的证据，因为雌性使用异种雄性的精子，雄性和雌性杂交都是完全可育的。早熟隔离是实质性的，但不完整，似乎是这些物种之间生殖隔离的主要形式。如果这些物种确实杂交了，那么缺少合子后屏障可能会允许基因在它们之间流动。考虑到这些物种是最近才分化出来的，并且不知道是否同域的，由于缺乏内在的合子后隔离，早熟隔离的水平相对较强。有必要进一步研究生殖隔离屏障的地理和遗传变异特征，并确定导致生殖隔离的因素，以及隔离屏障和地理隔离对这些物种之间基因流动模式的影响。本文的在线版本（doi:10.1186/s12862-015-0328-y）包含补充材料，仅供授权用户使用。
During the speciation process several types of isolating barriers can arise that limit gene flow between diverging populations. Studying recently isolated species can inform our understanding of how and when these barriers arise, and which barriers may be most important to limiting gene flow. Here we focus on Drosophila suboccidentalis and D. occidentalis, which are closely related mushroom-feeding species that inhabit western North America and are not known to overlap in geographic range. We investigate patterns of reproductive isolation between these species, including premating, postmating prezygotic, and postzygotic barriers to gene flow. Using flies that originate from a single population of each species, we find that the strength of premating sexual isolation between these species is asymmetric: while D. occidentalis females mate with D. suboccidentalis males at a reduced but moderate rate, D. suboccidentalis females discriminate strongly against mating with D. occidentalis males. Female hybrids will mate at high rates with males of either species, indicating that this discrimination has a recessive genetic basis. Hybrid males are accepted by females of both species. We do not find evidence for postmating prezygotic or postzygotic isolating barriers, as females use the sperm of heterospecific males and both male and female hybrids are fully fertile. Premating isolation is substantial but incomplete, and appears to be the primary form of reproductive isolation between these species. If these species do hybridize, the lack of postzygotic barriers may allow for gene flow between them. Given that these species are recently diverged and are not known to be sympatric, the level of premating isolation is relatively strong given the lack of intrinsic postzygotic isolation. Further work is necessary to characterize the geographic and genetic variation in reproductive isolating barriers, as well as to determine the factors that drive reproductive isolation and the consequences that isolating barriers as well as geographic isolation have had on patterns of gene flow between these species. The online version of this article (doi:10.1186/s12862-015-0328-y) contains supplementary material, which is available to authorized users.
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影响因子：
3.8
作者：
Bray, M. J.;Werner, T.;Dyer, K. A.
通讯作者：
Dyer, K. A.
影响因子：
2.9
作者：
Nosil, Patrik
通讯作者：
Nosil, Patrik
影响因子：
16.8
作者：
Cutter, Asher D.
通讯作者：
Cutter, Asher D.
DOI：
10.1073/pnas.86.14.5464
发表时间：
1989-07-01
影响因子：
11.1
作者：
COYNE, JA
通讯作者：
COYNE, JA
影响因子：
64.8
作者：
NOOR, MA
通讯作者：
NOOR, MA