Structural Studies of a UDP-glucuronosyltransferase gene from the plaice (Pleuronectes platessa)

A partial length cDNA coding for the putative PAH-inducible phenol-conjugating UDP-glucururonosyltransferases (UGT) isoform of plaice was used to isolate overlapping clones from a plaice genomic library. Sequence analysis revealed the presence of a complete gene spanning 4.1 kb for a plaice UGT which showed a strong conservation in exon structure, amino acid character and amino acid sequence with mammalian UGT1 family genes, although additional alternative upstream exon 1s were not identified in the present study. Southern blot analysis revealed a low copy number for the gene and some degree of structural polymorphism in gene structure between individuals. This was also reflected in the finding that there were significant variations between the nucleotide sequences of the plaice gene and the cDNA previously isolated from a different individual fish. Future studies will investigate the possibility that there may be phenotypic variations which could lead to alterations in susceptibility to pollutant toxicity.