Tandem Repeats Contribute to Coding Sequence Variation in Bumblebees (Hymenoptera: Apidae)

Area of Science:

• Genomics
• Evolutionary Biology
• Insect Molecular Biology

Background:

• Tandem repeats (TRs) are dynamic genomic regions.
• Mutations in TRs contribute to genetic variation and adaptation.
• Bumblebees are vital pollinators, but their adaptive mechanisms are poorly understood.

Purpose of the Study:

• Investigate the role of TRs in generating genetic variation in bumblebees.
• Explore how TRs might facilitate adaptation to diverse habitats.

Main Methods:

• Identified and characterized TRs in the buff-tailed bumblebee (Bombus terrestris) genome.
• Compared TRs between B. terrestris and a congener, B. impatiens.
• Confirmed TR variability in coding regions using PCR amplification.

Main Results:

• Discovered 26,595 TRs in B. terrestris, with 66.7% in genic regions.
• Identified 1,137 length-variable TRs between species, including 101 in coding regions.
• Found that 87% of genes with variable TRs in coding sequences are involved in transcriptional regulation.

Conclusions:

• TRs contribute significantly to coding sequence variation in bumblebees.
• TR-driven protein diversification, particularly in transcriptional regulators, may facilitate bumblebee adaptation.
• TRs represent a key source of adaptive potential in bumblebee populations.