SEQUENCE AND EXPRESSION OF THE MURINE HOXD-3 HOMEOBOX GENE

Murine Hoxd-3 (Hox 4.1) genomic DNA and cDNA and Hoxa-3 (Hox 1.5) cDNA were cloned and sequenced, The homeodomains of Hoxd-3 and Hoxa-3 and regions before and after the homeodomain are highly conserved. Both Ho xd-3 and Hoxa-3 proteins have a proline-rich region that contains cons ensus amino acid sequences for binding to Src homology 3 domains of so me signal transduction proteins, Northern blot analysis of RNA from 8- to 11-day-old mouse embryos revealed a 4.3-kb species of Hoxd-3 RNA, whereas a less abundant 3.0-kb species of Hoxd-3 RNA was found in RNA from 9- to 11-day-old embryos. Two species of Hoxd-3 poly(A)(+) RNA, 4 .3 and 6.0 kb in length, were found in poly(A)(+) RNA from adult mouse kidney, but not in RNA from other adult tissues tested, Hoxd-3 mRNA w as detected by in situ hybridization in 12-, 14-, and 17-day-old mouse embryos in the posterior half of the myelencephalon, spinal cord, dor sal root ganglia, first cervical vertebra, thyroid gland, kidney tubul es, esophagus, stomach, and intestines.