Magdalena Popesco and colleagues(2006) looked for genes with multiple copies with differences in their number between humans and apes.”The human lineage-specific amplification was due to an unknown gene ,MGC8902 which is predicted to encode multiple copies of a protein domain of unknown function(DUF1220) .DUFF 1220 domains are highly expressed in brain regions associated with higher cognitive function, and in brain show neuron-specific expression preferentially in cell bodies and dendrites.
…so there are two stories here. One is about the multiple duplication of MGC8902 on the human lineage. The draft human genome has 49 copies of it, chimpanzees have only 10.
… a seperate story is about the proliferation of this DUF1220 domain, which occurs in many proteins. This domain increased in copy number on the human lineage compared to chimpanzees, the African ape lineage compared to orangutans, and primates compared to other mammals.”