Migration genetics take flight: genetic and genomic insights into monarch butterfly migration

• Published in: Current opinion in insect science 2023-10, Vol.59, p.101079-101079, Article 101079
• Main Authors: Freedman, Micah G, Kronforst, Marcus R
• Format: Article
• Language: English
• Subjects: calcium; circadian clocks; Danaus plexippus; diapause; flight; genomics; insects; insulin; migratory behavior; overwintering; population genetics; transcription (genetics); vitamin A
• ISSN: 2214-5745; 2214-5745
• DOI: 10.1016/j.cois.2023.101079

Monarch butterflies have emerged as a model system in migration genetics. Despite inherent challenges associated with studying the integrative phenotypes that characterize migration, recent research has highlighted genes and transcriptional networks underlying aspects of the monarch’s migratory syndrome. Circadian clock genes and the vitamin A synthesis pathway regulate reproductive diapause initiation, while diapause termination appears to involve calcium and insulin signaling. Comparative approaches have highlighted genes that distinguish migratory and nonmigratory monarch populations, as well as genes associated with natural variation in propensity to initiate diapause. Population genetic techniques demonstrate that seasonal migration can collapse patterns of spatial structure at continental scales, whereas loss of migration can drive differentiation between even nearby populations. Finally, population genetics can be applied to reconstruct the monarch’s evolutionary history and search for contemporary demographic changes, which can provide relevant context for understanding recently observed declines in overwintering North American monarch numbers. •Monarch butterflies (Danaus plexippus) have emerged as a model system in ecological genomics.•Transcriptional processes associated with reproductive diapause initiation and termination have recently been identified.•Recent global range expansion enables population genomic comparisons of migratory versus nonmigratory monarchs.•Population genetic approaches have shown connectedness among migratory monarchs and divergence among nonmigratory monarchs.•Population genetic techniques can be applied to provide context for monarch conservation efforts.