Drosophila duplicate genes evolve new functions on the fly

Area of Science:

• Evolutionary biology
• Genomics
• Molecular biology

Background:

• Gene duplication is a major driver of phenotypic innovation.
• Mechanisms governing the retention and functional evolution of duplicate genes remain unclear.

Purpose of the Study:

• To develop and apply a genome-wide method for classifying gene duplication processes.
• To investigate the timing and location of new function acquisition in duplicate genes.

Main Methods:

• Developed a novel genome-wide method comparing expression profiles of duplicate genes and ancestral orthologs.
• Applied the method to spatial gene expression data in two Drosophila species.

Main Results:

• Most young duplicate genes acquire new functions rapidly, within millions of years.
• New functions predominantly arise in younger gene copies.
• Young duplicates show testes-specific expression, while older duplicates are broadly expressed, supporting the "out-of-testes" model.

Conclusions:

• Gene duplication is a rapid source of functional novelty.
• The "out-of-testes" hypothesis is strongly supported by expression patterns of young duplicates.
• Natural selection plays a crucial role in the evolution of novel phenotypes via gene duplication.