Sequence, expression and genetic mapping of a rainbow trout retinoblastomacDNA

A full-length cDNA for retinoblastoma (RB1) has been cloned from a cDNA lib rary prepared from 3-week-old rainbow trout (Oncorhynchus mykiss) eyed embr yos. The trout RB1 cDNA encodes a predicted protein of 910 amino acids and is the most divergent cloned retinoblastoma gene sequence to date. RT-PCR s tudies reveal high levels of RB1 expression by the second week of embryogen esis, which remains uniformly expressed until hatching. Expression studies of adult fish tissues show the RB1 gene to be expressed in all tissues exam ined, including the oesophagus, eye, liver, intestine, posterior and anteri or kidney, skin, stomach, muscle, spleen, gill, swim bladder, gonads and br ain. The RB1 gene appears to be a single copy gene based on Southern analys is, and maps to linkage group XVI in the trout genome map. Polymorphisms in the RB1 gene and in closely linked markers should facilitate LOH analysis of RB1. (C) 1999 Elsevier Science B.V. All rights reserved.