Identification of the murine Hox-c12 and Hox-c13 homeoboxes on yeast artificial chromosomes.

The structure of the Antennapedia-class homeobox gene clusters is highly conserved in human and mouse. Of all the human homeobox genes known, only HOX-C12 and HOX-C13 have not also been identified in mouse. These two genes are located at the extreme 5' end of the human HOX-C cluster and are predicted to be located in a similar position on the murine Hox-c cluster. We have isolated two yeast artificial chromosomes (YACs) containing the murine Hox-c cluster. We designed primers specific to the human HOX-C12 and -C13 homeoboxes and used the polymerase chain reaction and sequencing to identify the homeobox of the murine orthologs of these two genes on one of the YACs. Only the YAC containing the 5' end of the Hox-c cluster contained these sequences. Thus, we have identified two mouse homeobox genes not previously reported and established linkage of these genes to the 5' end of the mouse Hox-c cluster.