Diversity of sequences of polyadenylated cytoplasmic RNA from rainbow trout (Salmo gairdnerii) testis and liver

Abstract

The sequences complexity and diversity of polyadenylate cytoplasmic RNA derived from trout liver and testis were compared. The kinetics of hybridization of polyadenylated RNA from each of these tissues with compementary DNA (cDNA) synthesized by reverse transcriptase revealed 3 abundance classes for liver RNA, the 1st comprising 4 sequences, the 2nd 120 and the 3rd, 20,000; in contrast, testis RNA showed only 2 abundance classes containing 6 and 6100 different RNA sequences, respectively, and of average length 6 .times. 105 daltons. The extent of overlapping among those 2 RNA populations was further studied by performing heterologous annealing reactions between cDNA and a vast excess of mRNA. Liver mRNA was complementary to 80% of the testis cDNA. Conversely, testis mRNA reacted with only 25% of the liver cDNA. Experiments with fractionated cDNA probes indicated that the unshared sequences belonged mainly to the less frequent, most complex, class of mRNA.