Format

Send to:

Choose Destination
See comment in PubMed Commons below
Genetics. 2009 Jan;181(1):313-22. doi: 10.1534/genetics.108.091538. Epub 2008 Nov 17.

Formation and longevity of chimeric and duplicate genes in Drosophila melanogaster.

Author information

  • 1Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA. rrogers@oeb.harvard.edu

Abstract

Historically, duplicate genes have been regarded as a major source of novel genetic material. However, recent work suggests that chimeric genes formed through the fusion of pieces of different genes may also contribute to the evolution of novel functions. To compare the contribution of chimeric and duplicate genes to genome evolution, we measured their prevalence and persistence within Drosophila melanogaster. We find that approximately 80.4 duplicates form per million years, but most are rapidly eliminated from the genome, leaving only 4.1% to be preserved by natural selection. Chimeras form at a comparatively modest rate of approximately 11.4 per million years but follow a similar pattern of decay, with ultimately only 1.4% of chimeras preserved. We propose two mechanisms of chimeric gene formation, which rely entirely on local, DNA-based mutations to explain the structure and placement of the youngest chimeric genes observed. One involves imprecise excision of an unpaired duplication during large-loop mismatch repair, while the other invokes a process akin to replication slippage to form a chimeric gene in a single event. Our results paint a dynamic picture of both chimeras and duplicate genes within the genome and suggest that chimeric genes contribute substantially to genomic novelty.

PMID:
19015547
[PubMed - indexed for MEDLINE]
PMCID:
PMC2621179
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk