HEX: A novel homeobox gene expressed during haematopoiesis and conserved between mouse and human

Abstract

We describe the cloning of a novel homeodomain-contalning gene, which is highly conserved between mouse and human. The human cDNA was initially isolated from human haematopoietic tissue and denoted HEX (haematopoletlcally expressed homeobox). Sequence analysis of the coding sequences from mouse and the partial cDNA from human shows that the homeodomaln is most closely related to those of the Hlx and HOX11 proteins. The HEX gene is present as a single copy in the human genome. Analysis of murine genomic DNA shows, in addition to an intron-contalnlng gene homologous to HEX, the presence of a processed copy of the gene which has arisen within the last few million years. Analysis of human and murine haematopoietic cells and cell lines, revealed expression of the HEX gene in multipotentlal progenitors, as well as cells of the B-lymphocyte and myeloid lineages. However HEX was not expressed In T-lymphocytes or erythroid cells. This pattern of HEX gene expression suggests that it may play a role in haematopoietic differentiation. © 1993 Oxford University Press.