Franchini Paolo, Irisarri Iker, Fudickar Adam, Schmidt Andreas, Meyer Axel, Wikelski Martin, Partecke Jesko
Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, 78315, Radolfzell, Germany.
Mol Ecol. 2017 Jun;26(12):3204-3216. doi: 10.1111/mec.14108. Epub 2017 Apr 20.
Seasonal migration is a widespread phenomenon, which is found in many different lineages of animals. This spectacular behaviour allows animals to avoid seasonally adverse environmental conditions to exploit more favourable habitats. Migration has been intensively studied in birds, which display astonishing variation in migration strategies, thus providing a powerful system for studying the ecological and evolutionary processes that shape migratory behaviour. Despite intensive research, the genetic basis of migration remains largely unknown. Here, we used state-of-the-art radio-tracking technology to characterize the migratory behaviour of a partially migratory population of European blackbirds (Turdus merula) in southern Germany. We compared gene expression of resident and migrant individuals using high-throughput transcriptomics in blood samples. Analyses of sequence variation revealed a nonsignificant genetic structure between blackbirds differing by their migratory phenotype. We detected only four differentially expressed genes between migrants and residents, which might be associated with hyperphagia, moulting and enhanced DNA replication and transcription. The most pronounced changes in gene expression occurred between migratory birds depending on when, in relation to their date of departure, blood was collected. Overall, the differentially expressed genes detected in this analysis may play crucial roles in determining the decision to migrate, or in controlling the physiological processes required for the onset of migration. These results provide new insights into, and testable hypotheses for, the molecular mechanisms controlling the migratory phenotype and its underlying physiological mechanisms in blackbirds and other migratory bird species.
季节性迁徙是一种广泛存在的现象，在许多不同的动物谱系中都能发现。这种引人注目的行为使动物能够避开季节性不利的环境条件，去利用更适宜的栖息地。鸟类的迁徙行为已得到深入研究，它们在迁徙策略上表现出惊人的差异，从而为研究塑造迁徙行为的生态和进化过程提供了一个有力的系统。尽管进行了大量研究，但迁徙的遗传基础在很大程度上仍然未知。在这里，我们使用了最先进的无线电追踪技术来描述德国南部部分具有迁徙习性的欧歌鸫（欧亚鸲）种群的迁徙行为。我们通过高通量转录组学比较了留鸟和候鸟个体血液样本中的基因表达。序列变异分析显示，具有不同迁徙表型的欧歌鸫之间不存在显著的遗传结构。我们仅在候鸟和留鸟之间检测到四个差异表达基因，它们可能与贪食、换羽以及增强的DNA复制和转录有关。基因表达最显著的变化发生在候鸟之间，这取决于采血时间与它们出发日期的关系。总体而言，本分析中检测到的差异表达基因可能在决定迁徙的决策或控制迁徙开始所需的生理过程中发挥关键作用。这些结果为控制欧歌鸫及其他候鸟物种迁徙表型及其潜在生理机制的分子机制提供了新的见解和可检验的假设。
