Genetic differentiation and adaptive evolution of buff-tailed bumblebees in Asia

Area of Science:

• Population genomics
• Conservation genetics
• Insect ecology

Background:

• Bumblebees are crucial pollinators facing environmental change-induced declines.
• Understanding bumblebee population genetics and local adaptation is vital for conservation.
• Previous studies on buff-tailed bumblebee (Bombus terrestris) primarily focused on European populations, leaving Asian populations underrepresented.

Purpose of the Study:

• To investigate the population genetic structure of Asian and European buff-tailed bumblebees (Bombus terrestris).
• To identify the genetic basis of local adaptation in different environmental conditions.
• To assess the genetic diversity and conservation value of Asian populations.

Main Methods:

• Whole-genome resequencing of 77 wild and domesticated buff-tailed bumblebee (Bombus terrestris) samples from Asia and Europe.
• Population genomics analysis, including genetic differentiation (FST) and demographic analysis.
• Selective sweep analysis to identify genes under selection.

Main Results:

• Significant genetic differentiation (FST = 0.076) observed between Asian and European buff-tailed bumblebee (Bombus terrestris) populations.
• Asian populations exhibit distinct morphological and physiological differences, suggesting they are a unique genetic resource.
• Demographic analysis indicates increased effective population size during cold periods, pointing to cold-adapted traits; 331 genes under selection identified in Asian genomes, linked to adaptation to high UV radiation, low temperatures, and low precipitation.

Conclusions:

• Asian and European buff-tailed bumblebee (Bombus terrestris) populations represent distinct genetic units.
• Asian populations possess unique adaptations to their specific environmental conditions, making them a valuable genetic resource.
• Findings provide crucial insights for the conservation and management of buff-tailed bumblebee (Bombus terrestris) populations globally.