Olfactory GPCR Genes

Question

Olfactory GPCR genes:
A) include sequences encoding amino acids that are highly conserved in mammals.
B) include sequences encoding amino acids that are highly variable between gene family members to permit binding to diverse odorants.
C) probably underwent many duplications under selection pressure in rodents.
D) accumulate more nonsense mutations in species that rely less heavily on smell.
E) All of the above

Accepted Answer

There are many olfactory GPCR genes that share a common structure and highly conserved amino acid sequences but also have highly variable regions that would allow them to bind to different odor molecules. There are over a thousand functional OR genes in mice and rats but only 388 in humans, who do not rely as heavily on smell.