Cloning and characterization of ASH2L and Ash2l human and mouse homologs of the Drosophila ash2 gene

Drosophila ash2 belongs to the trithorax (trx) gene family. The ash2 produc t positively regulates expression of homeotic selector genes, and is implic ated in early development and formation of various disc patterns in the fru it fly. Through large-scale sequencing of human genomic DNA coupled with in silico gene trapping, we identified a gene (ASH2L) on chromosome 8p11.2 wh ose predicted product was highly homologous to ash2, characterized it, and identified its mouse counterpart. The human ash2 cDNA is 2368 bp long, enco ding 628 amino acids. The 16-exon gene spans more than 34 kb of genomic DNA between STS markers WI-9207 (centromere) and AFMA295ZD5 (telomere) on chro mosome 8, with transcription oriented telomere to centromere, The ash2 gene s are highly conserved among different species, including C. elegans and ye ast. The presence of a conserved bipartite nuclear localization signal and a PHD finger motif in the human ash2 gene suggests that the gene product wo uld function as a transcriptional regulator in humans, as its homologue doe s in Drosophila.