ORDER OF 6 LOCI AT 2Q24-Q31 AND ORIENTATION OF THE HOXD LOCUS

HOXD, a gene cluster of 9 homeobox genes of the Antennapedia class; EV X2, a homeobox gene related to Drosophila-even-skipped gene; DLX1 and DLX2, two homeobox genes related to the Drosophila distal-less gene; a nd TTN and NEB, the genes for the two giant molecules titin and nebuli n, both involved in the sarcomere structure, have been previously mapp ed to human 2q31-q32 and to mouse chromosome 2. We studied their relat ive order in human by applying FISH to three balanced chromosome rearr angements each with a breakpoint at 2q31. Unambiguous results led us t o map these genes and to orient the HOXD locus along chromosome 2 acco rding to the following order: cen, NEB, DLX1-DLX2, EVX2, HOXD (5'-3'), TTN, tel. Ah of these genes are part of a syntenic region covering 5- 10 cM and conserved since the divergence of humans and rodents, and th us the same loci order should be present in mouse. FISH in metaphases of approximately 500 bands localized NEB to 2q24.1-q24.2, while HOXD a nd TTN were localized to 2q31. (C) 1994 Academic Press, Inc.