Mammalian homeo box genes

In this paper the authors attempt to shed some light on this general problem of homeo box function by describing their experimental studies on the homeo box sequences in mammals, using the laboratory mouse and man as model systems. Both species are well described from a genetic point of view, and the mouse has been an object of developmental analysis for at least 75 years. The authors have been able to show that many of the homeo box sequences are organized into complexes, at least superficially similar to the Antennapedia and bithorax complexes of Drosophila. The authors also find a high degree of conservation in the organization of one of these complexes between man and mouse, suggestive of the same functional activity. The authors also show that the complexes encode RNA transcripts produced during mouse embryogenesis and, moreover, that the expression of the transcripts is likely to possess spatial and temporal specificity. All of these findings are consistent with the view that homeo box sequences in mammals are genetically functional, and may contribute to the regulation of the developmental process.