A mouse homoeo box gene is expressed during embryogenesis and in adult kidney

The homoeo box sequence of Drosophila is an element located in several genes that regulate segmentation and segment identity; it has homologues in the genomes of vertebrate species and a number of homoeo box-containing recombinant DNA clones have been isolated from Xenopus, man and mouse. In the present study we have isolated from a library of murine DNA a recombinant lambda clone (H24.1) which contains a sequence closely homologous to the homoeo box within the Drosophila Antennapedia (Antp) gene. The protein sequence of the homoeo domain is identical to that encoded by Hu-1, one of a the pair of closely linked homoeo boxes in the human genome. We have used a sensitive RNase protection assay to examine transcription of the H24.1 gene during mouse development, and in adult tissues. We report that the gene is transcribed from as early as 7.5 days post coitum (p.c.), with maximum expression at days 11.5 and 12.5 p.c. The transcript is enriched in embryonic spinal cord and brain at day 12.5 p.c., and in adult kidney.