Data from: Animal tracking meets migration genomics: transcriptomic analysis of a partially migratory bird species

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 non-significant
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.