The timing of major life-history events, such as migration and moult, is set by endogenous circa-dian and circannual clocks, that have been well characterized at the molecular level. Conversely,the genetic sources of ...The timing of major life-history events, such as migration and moult, is set by endogenous circa-dian and circannual clocks, that have been well characterized at the molecular level. Conversely,the genetic sources of variation in phenology and in other behavioral traits have been sparsely ad-dressed. It has been proposed that inter-individual variability in the timing of seasonal events mayarise from allelic polymorphism at phenological candidate genes involved in the signaling cascadeof the endogenous clocks. In this study of a long-distance migratory passerine bird, the willowwarbler Phylloscopus trochilus, we investigated whether allelic variation at 5 polymorphic loci of 4candidate genes （Adcyapl, Clock, Crebl, and Npas2）, predicted 2 major components of the annualschedule, namely timing of spring migration across the central Mediterranean sea and moultspeed, the latter gauged from ptilochronological analyses of tail feathers moulted in the Africanwinter quarters. We identified a novel Clockgene locus （Clock region 3） showing polyQ polymorph-ism, which was however not significantly associated with any phenotypic trait. Npas2 allele sizepredicted male （but not female） spring migration date, with males bearing longer alleles migratingsignificantly earlier than those bearing shorter alleles. Crebl allele size significantly predicted male（but not female） moult speed, longer alleles being associated with faster moult. All othergenotype-phenotype associations were statistically non-significant. These findings provide newevidence for a role of candidate genes in modulating the phenology of different circannual activ-ities in long-distance migratory birds, and for the occurrence of sex-specific candidate gene effects.展开更多
文摘The timing of major life-history events, such as migration and moult, is set by endogenous circa-dian and circannual clocks, that have been well characterized at the molecular level. Conversely,the genetic sources of variation in phenology and in other behavioral traits have been sparsely ad-dressed. It has been proposed that inter-individual variability in the timing of seasonal events mayarise from allelic polymorphism at phenological candidate genes involved in the signaling cascadeof the endogenous clocks. In this study of a long-distance migratory passerine bird, the willowwarbler Phylloscopus trochilus, we investigated whether allelic variation at 5 polymorphic loci of 4candidate genes （Adcyapl, Clock, Crebl, and Npas2）, predicted 2 major components of the annualschedule, namely timing of spring migration across the central Mediterranean sea and moultspeed, the latter gauged from ptilochronological analyses of tail feathers moulted in the Africanwinter quarters. We identified a novel Clockgene locus （Clock region 3） showing polyQ polymorph-ism, which was however not significantly associated with any phenotypic trait. Npas2 allele sizepredicted male （but not female） spring migration date, with males bearing longer alleles migratingsignificantly earlier than those bearing shorter alleles. Crebl allele size significantly predicted male（but not female） moult speed, longer alleles being associated with faster moult. All othergenotype-phenotype associations were statistically non-significant. These findings provide newevidence for a role of candidate genes in modulating the phenology of different circannual activ-ities in long-distance migratory birds, and for the occurrence of sex-specific candidate gene effects.
