Description
Hox genes are key regulators of development. In mammals, the study of these genes is greatly confounded by their large number, overlapping functions, and their interspersed shared enhancers. In this report, we describe a novel recombineering strategy that was used to introduce simultaneous frameshift mutations into the flanking Hoxa9, Hoxa10, and Hoxa11 genes, as well as their paralogs on the HoxD cluster. The resulting mutant mice displayed dramatic homeotic transformations of the reproductive tracts, with uterus anteriorized towards oviduct and the vas deferens anteriorized towards epididymis. The Hoxa9,10,11 mutant mice provided a sensitized genetic background that allowed the discovery of Hoxd9,10,11 reproductive tract patterning function. Both shared and distinct Hox functions were defined. The HoxD genes played a crucial role in the regulation of the uterine immune function. Non-coding nonpolyadenylated RNAs were among the key Hox targets. In addition, we observed a surprising anti-dogmatic posteriorization of the uterine epithelium.