| Abstract Detail
Conference Wide Miller, Ryan [1], Olmstead, Richard [1]. The mechanism of concerted evolution in rbcS in Solanaceae. CONCERTED evolution is the non-independent evolution of gene copies in a multigene family and can act to homogenize members and prevent acquisition of new function. Despite numerous studies demonstrating evidence for concerted evolution, the mechanism by which it operates is still poorly understood and many questions remain unexplained. Previous studies have shown a pattern of concerted evolution among the three loci encoding the small subunit of Rubisco (rbcS) in three disparate species of Solanaceae (Petunia, tobacco, and tomato) where paralogs (genes related by duplication) are more similar than orthologs (genes related by speciation). In contrast, two closely related species in Solanaceae, tomato and potato, have rbcS orthologs that are more similar than are their paralogs, indicating that speciation is occurring faster than concerted evolution in this lineage. Two hypotheses have been proposed for the pattern of concerted evolution in Solanaceae: selection acting on the Rubisco small subunit amino acid sequence homogenizes coding DNA among copies within a species, and interchromosomal gene conversion within a species acting to homogenize rbcS copies. If the pattern of concerted evolution is by gene conversion then the individual events homogenizing paralogs of rbcS will be evident in exact conversions of tracts of DNA. Under the selection hypothesis, more silent nucleotide polymorphisms will be shared between orthologs than paralogs. We present results of a comparison of rbcS sequences from a species closely related and progressively more distantly related to tomato and potato to deduce gene conversion events or homogenizing selection.
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1 - University of Washington, Biology, Campus Box 355325, Seattle, WA, 98195, USA
Keywords:
rbcS
Rubisco
concerted evolution.
Session: Poster-154
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:381 |
