Аннотация:The nucleotide sequence, chromosomal assignment, and preliminary transcriptional analysis of four murine homeoboxes is presented. Three of these are linked to the Hox-2 gene complex on chromosome 11, whereas the fourth, Hox-4, was assigned to mouse chromosome 12. A comparative analysis of homeobox sequences reveals that two of our sequences represent the previously described Hox-2.2 and Hox-2.3 loci, whereas a third, mhl9, could represent the predicted Hox-2.6 locus. Homeoboxes Hox-2.2 and Hox-2.3 are the cognates of two previously reported human homeoboxes that belong to a similar gene cluster on a closely related human chromosome (Chr 17), suggesting that homeoboxes may have been preserved as clusters during evolution. Moreover Hox-4, mhl9, and the previously described Hox-1.5 homeobox form a separate subgroup of mammalian homeoboxes (90–92% amino acid and nucleotide homology). All four homeoboxes are expressed in the mouse embryo. Of special interest is the expression of mhl9, a 4.2-kb transcript of which appears to be connected to the induced differentiation of Friend erythroleukemia cells.
