Two gene members of the murine HOX-5 complex show regional and cell-type specific expression in developing limbs and gonads

Abstract

This study reports the expression domains of two murine HOX gene members of the HOX-5 complex (Hox-5.2, Hox-5.3). These two genes have very similar homeo-domain sequences, as well as temporal and spatial specificities of expression. They are both expressed at very posterior levels in the central nervous system, in sclerotome derivatives and in a few internal organs. In addition to these expression domains which are shared with other HOX genes, transcripts from both Hox-5.2 and Hox-5.3 are present at high levels in developing limbs. After an early homogeneous expression in mesodermal limb bud cells, transcription becomes restricted to cartilage-differentiating cells. In addition, Hox-5.2 is a marker for gonadal development. The possible involvement of such genes during inductive processes or organogenesis is discussed.