Duplication and concerted evolution in a master sex determiner under balancing selection

Area of Science:

• * Evolutionary biology
• * Molecular genetics
• * Genomics

Background:

• * The transformer (tra) gene regulates somatic sexual differentiation in insects.
• * Understanding the evolution of key developmental genes like tra is crucial.

Purpose of the Study:

• * To investigate the evolutionary dynamics of the transformer (tra) gene in ants and bees.
• * To determine if concerted evolution plays a role in the diversification of the tra gene family.

Main Methods:

• * Comparative sequence analysis of tra gene paralogues across multiple ant and bee species.
• * Examination of gene location and synteny conservation.
• * Detection of positive selection signatures within tra paralogues.

Main Results:

• * Six of seven sequenced ant species possess two highly similar tra paralogues, suggesting recent concerted evolution after duplication.
• * Ant tra paralogues are often located adjacently, conserved across genomic rearrangements.
• * Evidence of inter-locus recombination and positive selection was found in some ant tra paralogues.
• * Similar duplication and adjacency patterns were observed in three bee species, with evidence of recombination.

Conclusions:

• * Concerted evolution, including recombination and conserved synteny, appears to be a significant force shaping the tra gene family in ants and bees.
• * This suggests an adaptive role for concerted evolution in the functional diversification or maintenance of duplicated genes.