After publication of this work , we found evidence for a gene (or two tandem genes) orthologous to Leutx in a genome assembly for the African elephant produced by the Broad Institute and accessible on the UCSC Genome Browser, assembly version Broad/loxAfr3 . Elephant Leutx homeodomain sequences are highly divergent from that of human LEUTX (48% identity), but regions of identity outside the homeodomain plus genomic synteny (Figure 1) confirm orthology. We also found divergent putative Leutx orthologues in some other mammals including dog, cat, horse, pig and cow but, as reported in our original publication, not in rodents or outside the placental mammals. These findings imply that Leutx did not originate in primate evolution as we originally suggested , but arose early in the radiation of placental mammals and was secondarily lost from rodents. This finding strengthens our original conclusion that rodents have experienced far more homeobox gene loss than have primates. Leutx is added to Ventx, Argfx, Dprx, Shox, Rax2, LOC647589, Tprx1 and Nanognb on the list of homeobox genes lost in the evolutionary lineage leading to rodents (Figure 2).
Department of Zoology, University of Oxford
Zhong Y-F, Holland PWH: The dynamics of vertebrate homeobox gene evolution: gain and loss of genes in mouse and human lineages.BMC Evolutionary Biology 2011, 11:169.PubMedView Article
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