| Anonymous | |
|---|---|
| Log in for more site access. | |
 | |
Olfactory Receptors
Certainty Style Key
Hover over keys for definitions:
True
Likely
Speculative
Human Uniqueness Compared to "Great Apes":
Absolute DifferenceMOCA Domain:
Gene Family Expansion and LossThe olfactory receptor (OR) gene family contains approximately 1000 genes for olfaction, and humans have experienced varying lineage-specific alterations in these genes. Of the ~1000 genes within the family, over 60% are pseudogenized in humans, a percentage twice as high as other non-human primates. Additionally, humans have accumulated mutations four times faster in these genes than other primates, one example being in the OR gene 912-913, which in humans has experienced a nonsense mutation rendering it nonfunctional. In contrast to this general pattern of loss/pseudogenization, the OR-A gene specifically has expanded from 1-2 copies in chimpanzee and gorilla to 7-11 copies in humans, and a region of subtelomeric DNA duplicated to numerous chromosomes in the human, but not gorilla or chimp, lineage contains additional OR genes.
The Human Difference:
Gene duplication
Pseudogenization
References:
Gilad Y, Man O, Paabo S et al (2003). Human specific loss of olfactory receptors genes. PNAS March 18; 100(6):3324-3327.
Mefford H and Trask BJ (2002). The complex structure and dynamic evolution of human subtelomeres. Nature Reviews Genetics 3:91-102.
Trask BJ, Friedman C, Martin-Gallardo A et al (1998). Members of the olfactory receptor gene family are contained in large blocks of DNA duplicated polymorphically near the ends of human chromosomes. Hum Mol Genet Jan; 7(1):13-26.
Roquier S, Friedman C, Delettre C et al (1998). A gene recently inactivated in human defines a new olfactory receptor family in mammals. Hum Mol Genet 7(9):1337-1345.