Board Thread:Naruto Discussions/@comment-28861328-20140618060932/@comment-5014598-20140618072720

Nowhere was it said that transmigrants appeared only in the bloodline of the transmigrated. Though it certainly seems that all of Indra's were in the Uchiha. But we don't know if all of them were. That was never explicitly stated. One could've been ahyuga for all we know.