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Published on: February 26, 2016
Adaptive evolution of color vision genes in higher primates
S K Shyue1, D Hewett-Emmett, H G Sperling
1Human Genetics Center, School of Public Health, University of Texas, Houston 77225, USA.
Science (New York, N.Y.)
|September 1, 1995
Summary
Squirrel monkeys and marmosets show highly divergent color photo-pigment genes, suggesting independent evolution or extensive gene conversion. These distinct alleles likely persisted for millions of years due to overdominant selection.
Area of Science:
- Evolutionary genetics
- Primate molecular evolution
- Visual pigment gene evolution
Background:
- The X-linked color photo-pigment locus is crucial for vision.
- Polymorphisms in this locus can lead to variations in color perception.
- Understanding the evolutionary dynamics of these genes provides insights into primate adaptation.
Purpose of the Study:
- To analyze the intron 4 sequences of polymorphic alleles at the color photo-pigment locus in squirrel monkeys and marmosets.
- To investigate the evolutionary history and divergence patterns of these alleles within each species.
- To infer the mechanisms driving allele diversity and persistence.
Main Methods:
- Sequencing of intron 4 regions of the X-linked color photo-pigment gene.
- Comparative sequence analysis across multiple alleles within each primate species.
- Phylogenetic analysis and molecular population genetics approaches.
Main Results:
- Exceptionally divergent polymorphic alleles were identified in both squirrel monkeys and marmosets.
- The triallelic systems appear to have evolved independently in each lineage or involved extensive gene conversion.
- Evidence suggests at least seven deletions/insertions (14 total) were homogenized among alleles within each species.
Conclusions:
- The observed allele divergence suggests a long evolutionary persistence, likely over 5 million years.
- Overdominant selection is proposed as the primary mechanism maintaining these highly divergent alleles.
- The findings highlight unique evolutionary pathways for visual pigment genes in New World monkeys.
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