Sex chromosome mosaicism and hybrid speciation among tiger swallowtail butterflies.
Sex chromosome mosaicism and hybrid speciation among tiger swallowtail butterflies.
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老虎燕尾蝴蝶中的性染色体镶嵌和混合物种形成。
DOI：
10.1371/journal.pgen.1002274
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发表时间：
2011-09
期刊：
影响因子：
4.5
通讯作者：
Kronforst MR
中科院分区：
文献类型：
--
作者：
Kunte K;Shea C;Aardema ML;Scriber JM;Juenger TE;Gilbert LE;Kronforst MR
杂交物种形成，或由于两个亲本物种之间的杂交而形成子代物种，是多样化的潜在重要手段，因为它从现有的变异中产生新的形式。然而，导致杂交物种起源和维持的因素在很大程度上尚不清楚。在这里，我们表明北美蝴蝶阿巴拉契亚凤蝶是一个杂交物种，具有来自灰凤蝶和加拿大凤蝶的基因组混合物。阿巴拉契亚凤蝶具有嵌合表型，推测其是青花凤蝶和加拿大凤蝶的性连锁特征相结合的结果。我们发现，阿巴拉契亚松鼠的 Z 连锁基因与较冷的热栖息地相关，是从加拿大松鼠遗传的，而其 W 连锁拟态和线粒体 DNA 是从青松鼠遗传的。此外，全基因组 AFLP 标记显示阿巴拉契亚松起源中每个亲本物种的贡献几乎相等，表明它是由亲本物种之间的爆发性杂交形成的，随后几乎没有回交。然而，基于分子数据的遗传分化、聚类和多态性分析也表明，阿巴拉契亚松在遗传上与两个亲本物种都不同。种群遗传模拟显示，阿巴拉契亚松比亲本物种年轻得多，基因从灰白松和加拿大松单向流向阿巴拉契松。最后，系统发育分析与祖先状态重建相结合，表明定义阿巴拉契亚松鼠嵌合表型的两个性状，即强制性蛹滞育和拟态，分别在加拿大松鼠和青松鼠中独特进化，然后通过杂交重组形成阿巴拉契松鼠。这些结果表明，自然选择和性相关性状可能在阿巴拉契亚松作为杂交种的起源和维持中发挥了重要作用。特别是，尽管与两个亲本物种都有接触和偶尔的杂交，但与陡峭的温跃层相关的生态屏障似乎仍维持着阿巴拉契亚松的独特的嵌合基因组。两个物种之间的杂交有时可能会导致第三个物种的形成。虽然这种现象很有趣，因为它可以从现有的变异中产生新物种，但它在动物中很少见。因此，导致杂交物种起源和维持的因素在很大程度上是未知的。在这里，我们发现阿巴拉契亚凤蝶似乎是一个杂交物种，它的基因组贡献几乎相等于蓝凤蝶和加拿大凤蝶。两组性状定义了阿巴拉契亚蝴蝶的混合表型：与加拿大蝴蝶一样，它栖息在寒冷的栖息地，每年产生一代；与灰蝴蝶一样，它模仿有毒蝴蝶，其雌性是二态性的。负责这些性状的基因位于两条不同的性染色体上。我们的遗传数据表明，阿巴拉契亚松鼠从加拿大松鼠那里继承了与寒冷栖息地相关的性染色体，而从青松鼠那里继承了与拟态和二态性相关的性染色体。历史上的气候变化可能促进了阿巴拉契亚松的起源，我们的数据表明，这与北美的最后一个间冰期相一致。这个例子显示了性相关性状的重要性以及自然选择在杂交物种的起源和维持中的潜在作用。
Hybrid speciation, or the formation of a daughter species due to interbreeding between two parental species, is a potentially important means of diversification, because it generates new forms from existing variation. However, factors responsible for the origin and maintenance of hybrid species are largely unknown. Here we show that the North American butterfly Papilio appalachiensis is a hybrid species, with genomic admixture from Papilio glaucus and Papilio canadensis. Papilio appalachiensis has a mosaic phenotype, which is hypothesized to be the result of combining sex-linked traits from P. glaucus and P. canadensis. We show that P. appalachiensis' Z-linked genes associated with a cooler thermal habitat were inherited from P. canadensis, whereas its W-linked mimicry and mitochondrial DNA were inherited from P. glaucus. Furthermore, genome-wide AFLP markers showed nearly equal contributions from each parental species in the origin of P. appalachiensis, indicating that it formed from a burst of hybridization between the parental species, with little subsequent backcrossing. However, analyses of genetic differentiation, clustering, and polymorphism based on molecular data also showed that P. appalachiensis is genetically distinct from both parental species. Population genetic simulations revealed P. appalachiensis to be much younger than the parental species, with unidirectional gene flow from P. glaucus and P. canadensis into P. appalachiensis. Finally, phylogenetic analyses, combined with ancestral state reconstruction, showed that the two traits that define P. appalachiensis' mosaic phenotype, obligatory pupal diapause and mimicry, evolved uniquely in P. canadensis and P. glaucus, respectively, and were then recombined through hybridization to form P. appalachiensis. These results suggest that natural selection and sex-linked traits may have played an important role in the origin and maintenance of P. appalachiensis as a hybrid species. In particular, ecological barriers associated with a steep thermal cline appear to maintain the distinct, mosaic genome of P. appalachiensis despite contact and occasional hybridization with both parental species. Hybridization between two species may sometimes lead to the formation of a third species. While this phenomenon is of interest because it can generate new species from existing variation, it is rare in animals. Therefore, the factors responsible for the origin and maintenance of hybrid species are largely unknown. Here we show that the butterfly Papilio appalachiensis appears to be a hybrid species, which received nearly equal contributions to its genome from P. glaucus and P. canadensis. Two sets of traits define P. appalachiensis' hybrid phenotype: like P. canadensis it inhabits a cold habitat and has a single generation every year, and like P. glaucus it mimics a toxic butterfly and its females are dimorphic. The genes responsible for these traits are on two different sex chromosomes. Our genetic data show that P. appalachiensis inherited the sex chromosome associated with the cold habitat from P. canadensis, whereas it inherited the sex chromosome associated with mimicry and dimorphism from P. glaucus. Historical climate change may have facilitated the origin of P. appalachiensis, which our data suggest coincided with the last interglacial period in North America. This example shows the importance of sex-linked traits and a potential role for natural selection in the origin and maintenance of hybrid species.
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影响因子：
56.9
作者：
Gompert, Zachariah;Fordyce, James A.;Nice, Chris C.
通讯作者：
Nice, Chris C.
DOI：
10.1073/pnas.96.9.5107
发表时间：
1999-04-27
影响因子：
11.1
作者：
Albertson, RC;Markert, JA;Kocher, TD
通讯作者：
Kocher, TD
影响因子：
0.9
作者：
Deering, MD;Scriber, JM
通讯作者：
Scriber, JM
影响因子：
16.8
作者：
Jiggins, CD;Mallet, J
通讯作者：
Mallet, J
DOI：
10.1073/pnas.0611164104
发表时间：
2007-02-20
影响因子：
11.1
作者：
Hey, Jody;Nielsen, Rasmus
通讯作者：
Nielsen, Rasmus