On the '
Are there evolutionary reasons for reproduction?' thread Barbara asked about the existence of a common retroviral origin for certain genes involved in placental development. Mr Jack then commented that ...
Mr. Jack writes:
the placental mammals (eutheria) appear to all share the same gene derived from a retrovirus that is involved in placental formation. This implies that the insertion happened once for all placental mammals. Certain marsupials have very placenta like structures, that appear to be separately evolved; I do not know whether these share the same genetic basis.
I don't know which gene they were discussing but one I am aware of is
Syncytin related gene family which is found throughout primates and Glires (rodents and lagomorphs). I have also seen reviews suggesting that there were distinct retroviruses involved in different placental mammals (
Volff and Brosius, 2007 (PDF)).
So I was wondering if this was worthy of a discussion of its own and whether Mr. Jack could go into more detail on the genes he was referring to.
TTFN,
WK