The misidentification of bacterial genes as human cDNAs: was the human D-1 tumor antigen gene acquired from bacteria?

The initial analysis of the draft copy of the human genome sequence revealed the presence of several genes that were proposed to have been directly transferred from bacteria. We investigated the human D-1 antigen as a potential lateral transfer event. We report that although the human D-1 antigen seems to be an excellent candidate for lateral transfer, it is a contaminating bacterial sequence present in a human cDNA library that was included in the human genome analysis. Furthermore, several other genes present in the publicly available databases that were included in the analysis of the human genome are also likely contaminating bacterial sequences present in cDNA libraries.