Isolation and characterization of a novel human paired-like homeodomain-containing transcription factor gene, VSX1, expressed in ocular tissues

Homeodomain transcription factors control cell fates during the development of all animals. The paired-like subfamily of homeodomain proteins has been particularly implicated in ocular development in different species, In thi s paper we report the cDNA sequence, genomic structure, localization, and e xpression data of a novel paired-like homeobox-containing gene, VSX1, isola ted from a human embryonic craniofacial cDNA library using the degenerate-P CR approach. The composed VSX1 cDNA sequence of 1433 bp was predicted to en code a protein of 365 amino acid residues, Maximal homology at the protein level was identified with the paired-like homeoproteins of the CVC-domain f amily: 92-97% identity was seen in the homeodomain region with 55% overall identity to zebrafish and goldfish Vsx1 and 35% overall identity to goldfis h Vsx2 and murine Chx10, The gene was found to consist of five exons that a re distributed over 6.2 kb of genomic sequence. VSX1 was localized to the 2 0p11-q11 region, which is homologous with the distal part of mouse chromoso me 2, Expression of VSX1 was detected in embryonic craniofacial and adult o cular tissues. Several ocular phenotypes have been mapped to the VSX1 regio n in both human and mouse genomes, and its candidacy for these disorders is discussed. (C) 2000 Academic Press.