Conservation of a glutathione S-transferase in marine and freshwater fish

We have previously reported the isolation and cloning of glutathione S-tran sferase (GST) cDNAs from two marine fish, English sole (Pleuronectes vetulu s) and starry flounder (Platichthys stellatus), that exhibited >95% identit y to plaice (Pleuronectes platessa) GST-A Aquatic Toxicol., 44, 171-182]. I n the present study, we have used reverse transcription-polymerase chain re action (RT-PCR) analysis to isolate a 471 nucleotide GST-like cDNA from lar gemouth bass (Micropterus salmoides) liver. Sequence identity of the largem outh bass partial cDNA to plaice GST-A was approximately 90%. Northern blot ting analysis using the partial GST cDNA from English sole as a probe detec ted a single band of approximately I kb in English sole liver and a slightl y larger GST-like band that was highly expressed in largemouth bass liver. In addition, a faint band of Similar size was recognized in brown bullhead (Ameriurus nebulosus) liver, but not in channel catfish (Ictalurus punctatu s) liver. In conclusion, we have extended our studies of GST expression in flatfish and have isolated an additional GST-A-like cDNA from a largemouth bass. Conservation of a GST-A like cDNA among certain marine flatfish and f reshwater species suggests an important function for this gene. (C) 2000 El sevier Science Ltd. All rights reserved.