Expression patterns of alternative transcripts of the zebrafish olfactomedin 1 genes.

Olfactomedin 1 (Olfm1) is a founding member of the family of olfactomedin domain-containing proteins. It is a secreted protein that performs different roles in different species. Although the molecular mechanisms of Olfm1 action are not known, its possible roles include the regulation of neural crest cell production, neuronal differentiation, and ischemic neuronal death in adult. Two zebrafish olfm1 genes (olfm1a and olfm1b) located on chromosomes 5 and 21 were identified in zebrafish genome. Four different transcripts are produced from each olfm1 gene. The distribution of these transcripts in the course of zebrafish early development was studied by in situ hybridization and quantitative RT-PCR. Different variants of olfm1 mRNA were present mainly in neurogenic tissues and demonstrated overlapping expression patterns.