DEVELOPMENTAL EXPRESSION OF CLASS-III AND CLASS-IV POU DOMAIN GENES IN THE ZEBRAFISH

Using redundant primers in a PCR based cloning strategy, POU-domain en coding sequences representing two different class III genes (brain-1.1 , brain-1.2) and one class IV gene (brain-3.1) were identified in zebr afish. Using the PCR clones to screen a zebrafish gastrula cDNA librar y, a third class III POU gene was identified (brain-1.0). RT-PCR assay s performed with gene-specific primers indicated that the four POU gen es exhibited distinct patterns of expression in developing embryos and adult fish. Like their mammalian homologs, the class III genes were e xpressed early in development and in the adult brain, while the class IV gene was poorly expressed during early development but highly expre ssed in the adult eye. Since two of the POU PCR clones were obtained f rom genomic DNA, the fish genes may also be similar to their mammalian homologs in being largely devoid of introns. (C) 1996 Academic Press, Inc.