Behavioural mechanisms of reproductive isolation between two hybridizing dung fly species
Behavioural mechanisms of reproductive isolation between two hybridizing dung fly species
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两种杂交粪蝇物种生殖隔离的行为机制
DOI：
10.1016/j.anbehav.2017.08.008
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发表时间：
2017
期刊：
影响因子：
2.5
通讯作者：
M. Schäfer
中科院分区：
文献类型：
--
作者：
Athene Giesen;W. Blanckenhorn;M. Schäfer
杂交成功率低。雌性而非雄性歧视异性交配伴侣。雌性交配行为的母系遗传。强化驱动的异种交配行为的生物地理变异。几乎没有证据表明存在针对杂交后代的性选择。研究导致生殖隔离的性状的表型分化和遗传基础是了解物种形成机制的重要途径。我们量化了4个新脓毒症种群的前合子分离程度和交配行为的地理差异，这些种群发生在与其姐妹种脓毒症的4个种群的异源、异源或同源中。为了深入了解数量遗传基础和选择对杂交表型的作用，我们还研究了f1杂交后代的交配行为以及与亲本群体的回交。我们的研究记录了在实验室条件下成功的杂交，杂种的异种配对频率较低，但f1杂种的配对频率较高，这表明杂交活力。对f1后代及其亲本回交的分析没有提供对杂交种进行性选择的证据。异种配对中较长的交配潜伏期表明物种识别，可能是由于表面或挥发性化学物质。雄性交配尝试的频率在物种或杂交配对之间没有很大差异，这表明雄性对交配伴侣没有歧视。雌性摇晃的持续时间，表明雌性选择和/或不愿意交配，在不同物种之间差异很大，似乎有助于避免异种雄性；这一特征部分是母系遗传的。重要的是，这两个物种的雌性在同感区对雄性的歧视比异种区更强烈，这表明了强化。异种亲本配对的较短交配期和f1杂交种的较长交配期提示精子转移的机械困难。总的来说，我们的研究强调了在共存的地理区域中，性状位移对杂交sepsid物种交配行为的重要影响。
HighlightsSuccessful but low rates of hybridization.Females but not males discriminate against heterospecific mating partners.Maternal inheritance of female mating behaviour.Biogeographical variation in heterospecific mating behaviour driven by reinforcement.Little evidence for sexual selection against hybrids.Characterization of the phenotypic differentiation and genetic basis of traits that can contribute to reproductive isolation is an important avenue to understand the mechanisms of speciation. We quantified the degree of prezygotic isolation and geographical variation in mating behaviour among four populations of Sepsis neocynipsea that occur in allopatry, parapatry or sympatry with four populations of its sister species Sepsis cynipsea. To obtain insights into the quantitative genetic basis and the role of selection against hybrid phenotypes we also investigated mating behaviour of F 1 hybrid offspring and corresponding backcrosses with the parental populations. Our study documents successful hybridization under laboratory conditions, with low copulation frequencies in heterospecific pairings but higher frequencies in pairings of F 1 hybrids signifying hybrid vigour. Analyses of F 1 offspring and their parental backcrosses provided little evidence for sexual selection against hybrids. Longer copulation latencies in heterospecific pairings indicate species recognition, probably due to surface or volatile chemicals. The frequency of male mating attempts did not differ greatly between species or hybrid pairings, suggesting no male discrimination of mating partners. Female shaking duration, signifying female choice and/or reluctance to mate, differed strongly between the species and appears to contribute to avoiding heterospecific males; this trait is partially maternal inherited. Importantly, females of both species discriminated more strongly against males in areas of sympatry than allopatry indicating reinforcement. Shorter copulations in heterospecific parental pairings and longer copulations in F 1 hybrids suggest mechanistic difficulties with sperm transfer. Overall, our study highlights an important role of character displacement affecting mating behaviour of hybridizing sepsid species in geographical areas of coexistence.