Isolation and sequence of cDNA clones coding for a member of the family of high mobility group proteins (HMG-T) in trout and analysis of HMG-T-mRNA's in trout tissues.

A specific oligonucleotide has been used to isolate a cDNA prepared from the mRNA for a trout High Mobility Group (HMG) protein closely related to trout HMG-T and bovine HMG 1 and 2 proteins. The sequence isolated more closely resembles bovine HMG-1 than the previously sequenced HMG-T protein in regions corresponding to the N terminal half of the protein. Northern blot analysis at low stringency indicated that 2 related sequences are expressed in total trout testis mRNA. Southern blots of total trout DNA indicate that several different forms of the homologous sequence are present in the trout genome and an estimate of copy number by dot-blot shows 4 HMG-T genes per trout sperm DNA equivalent. Analysis of mRNA from several trout tissues, including testis, liver and kidney indicates that expression of genes for histones and the larger HMG proteins in trout is not closely coupled.