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Transient Expression of Proteins by Hydrodynamic Gene Delivery in Mice
Published on: May 5, 2014
The apolipoprotein E (APOE) gene appears functionally monomorphic in chimpanzees (Pan troglodytes)
Annick M McIntosh1, Calvin Bennett, Dara Dickson
1Department of Anthropology, Yale University, New Haven, Connecticut, United States of America.
Plos One
|November 1, 2012
Summary
Apolipoprotein E (APOE) gene diversity is unique to humans. Chimpanzee APOE shows no coding variation, unlike humans, suggesting functional APOE polymorphism evolved uniquely in human evolution.
Area of Science:
- Genetics
- Evolutionary Biology
- Primatology
Background:
- The human apolipoprotein E (APOE) gene has three main alleles (E2, E3, E4) influencing lipoprotein binding and associated with traits like cholesterol, cardiovascular health, Alzheimer's disease risk, and longevity.
- APOE allele frequencies vary across human populations, with their evolutionary maintenance being a subject of debate.
- Previous studies indicated chimpanzee APOE is similar to human E4, but used limited samples and didn't explore intraspecific variation.
Purpose of the Study:
- To investigate potential intraspecific variation in the chimpanzee APOE gene.
- To compare chimpanzee APOE sequences with other ape genera and fossil hominins.
- To understand the evolutionary context of human APOE polymorphism.
Main Methods:
- Sequencing of the APOE gene in 32 chimpanzees (20 western subspecies, 12 eastern subspecies).
- Comparison of APOE sequences across available ape genera and fossil hominins.
- Analysis of coding and non-coding variations.
Main Results:
- No coding variation was found within or between chimpanzee subspecies.
- A single non-coding intronic SNP showed fixed differences between western and eastern chimpanzee subspecies.
- Bonobo APOE protein is identical to chimpanzee APOE; Denisovan APOE resembles human E4.
Conclusions:
- The lack of coding variation in chimpanzee APOE suggests functional APOE polymorphism is a unique characteristic of human evolution.
- This finding highlights the distinct evolutionary trajectory of the APOE gene in the human lineage.
- Further research into the selective pressures driving human APOE diversity is warranted.
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