Sequence analysis and tissue specific expression of human HOXA7

Abstract

A 3071-bp fragment containing the human HOXA7 gene was sequenced. It contained two exons, one intron, and two polyadenylation signals (AATAAA) at positions 1844 and 2923. The exon encoded 230 aa residues, while the hexapeptide, homeodomain, and C-terminal acidic domains were detected. When the total sequences were compared with those of murine Hoxa-7, the 5' untranslated region (UTR), exon I, intron, exon II, and 3' UTR exhibited 99, 92, 65, 85, and 72% homology, respectively. Through Northern analysis, about a 1.9-kb transcript was detected in the fetal kidney. Minor transcripts of 1.5 and 1.1-kb were also detected in the fetal liver as well as in the kidney. In the case of adult tissues, most of the tissues tested (lung, liver, skeletal muscle, kidney, pancreas, and placenta), except brain tissue, expressed a 5.3 kb transcript with various intensities. Our results here suggested that not only Abd-B type Hox genes, but the ones in paralogous groups I-VIII could generate multiple transcripts. The characterization of these tissue-specific and stage-specific alternative transcripts would help to understand the regulatory function of the HOXA7 gene during development, and possibly the pathology of human disease caused by Hox genes.