Developmental expression of alcohol dehydrogenase (ADH3) in zebrafish (Danio rerio)

Alcohol dehydrogenase (ADH) is the primary enzyme responsible for metabolis m of ethanol to acetaldehyde. One class of ADH has been described in fish, and has been found to be structurally similar to mammalian class III ADH (g lutathione-dependent formaldehyde dehydrogenase) but. functionally similar to class I ADH (primarily responsible for ethanol metabolism). We have clon ed a cDNA by RT-PCR from zebrafish (Danio rerio) liver representing the zeb rafish ADH3 gene product, with a coding region of 1131 nucleotides. The ded uced amino acid sequences share 90% identity to ADH3 from the marine fish S pares aurata, and 82 and 81%a identity to the mouse and human sequences, re spectively. Using a quantitative competitive RT-PCR assay. ADH3 mRNA was de tected at all timepoints analyzed and was, lowest between 8 and 24 h postfe rtilization. Thus, differential ADH3 expression may be at least partly resp onsible for temporal variations in the sensitivity of zebrafish embryos to developmental alcohol exposure. (C) 2001 Academic Press.