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Nonallelic gene conversion in the genus Drosophila
Claudio Casola1, Carrie L Ganote, Matthew W Hahn
1Department of Biology, Indiana University, Bloomington, IN 47405, USA. ccasola@indiana.edu
Genetics
|March 11, 2010
Summary
Gene conversion homogenizes paralogous genes across Drosophila species, affecting 1-9% of genes. While young duplicates show higher conversion, only 1-15% of gene trees are misled, indicating species-specific mechanisms.
Area of Science:
- Genomics
- Evolutionary Biology
- Molecular Genetics
Background:
- Nonallelic gene conversion is hypothesized to homogenize paralogous gene sequences.
- Understanding gene conversion's role is crucial for evolutionary genomics.
Purpose of the Study:
- To investigate the extent and characteristics of gene conversion in Drosophila gene families.
- To identify factors influencing gene conversion rates across species.
Main Methods:
- Genome-wide analysis of 2855 gene families (17,742 genes) across nine Drosophila species.
- Gene family size analysis and gene-tree/species-tree reconciliation to detect gene conversion events.
- Correlation analysis of gene conversion with paralog features like location, divergence, and GC content.
Main Results:
- Gene conversion events were detected in 2628 genes, with 1-9% of genes affected per species.
- Young gene duplicates exhibited higher conversion rates, but only 1-2% of their coding sequences were impacted.
- An estimated 1-15% of gene trees were misled by gene conversion, varying by lineage.
- Paralog features like location and divergence correlated with conversion, but no biased substitution was definitively found.
- Significant interspecies variation in gene conversion was observed, with the melanogaster group showing the lowest rates.
Conclusions:
- Gene conversion is a notable, yet often localized, homogenizing force among paralogous genes in Drosophila.
- Species-specific differences in gene conversion suggest distinct underlying molecular mechanisms.
- Further research is needed to elucidate the mechanistic basis of these observed interspecies variations.
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