Migration, mitochondria, and the yellow-rumped warbler

Discordance between mitochondrial and nuclear DNA has been noted in many systems. Asymmetric introgression of mitochondria is a common cause of such discordances, although in most cases the drivers of introgression are unknown. In the yellow-rumped warbler, evidence suggests that mtDNA from the eastern, myrtle warbler, has introgressed across much of the range of the western form, the Audubon's warbler. Within the southwestern United States myrtle mtDNA comes into contact with another clade that occurs in the Mexican black-fronted warbler. Both northern forms exhibit seasonal migration, whereas black-fronted warblers are nonmigratory. We investigated the link between mitochondrial introgression, mitochondrial function, and migration using novel genetic, isotopic, biochemical, and phenotypic data obtained from populations in the transition zone. Isotopes suggest the zone is coincident with a shift in migration, with individuals in the south being resident and populations further north be...

诸多类群中均已观察到线粒体DNA（mitochondrial DNA）与核DNA（nuclear DNA）之间的遗传不一致现象。线粒体的不对称遗传渐渗（introgression）是引发这类不一致现象的常见原因，但多数情况下，渐渗的驱动机制仍不明晰。在黄腰林莺（yellow-rumped warbler）类群中，已有证据显示东部月桂林莺（myrtle warbler）的线粒体DNA（mtDNA）已在西部类群奥杜邦林莺（Audubon's warbler）的大部分分布区内发生遗传渐渗。在美国西南部地区，月桂林莺的线粒体DNA与另一个源自墨西哥黑额林莺（Mexican black-fronted warbler）的演化支（clade）发生了接触。这两种北部类群均具有季节性迁徙习性，而黑额林莺则无迁徙习性。本研究利用从过渡带种群中获取的新颖遗传、同位素、生化及表型数据，探究了线粒体渐渗、线粒体功能与迁徙行为之间的关联。同位素数据表明，该过渡带与迁徙模式的转变相一致，南部个体为留居个体，而更北部的种群则……