A family of wheat embryo U2 snRNAs

Summary Evidence is presented for the existence of small nuclear RNAs in a higher plant species. Based on subcellular fractionation experiments, wheat embryos contain at least four putative snRNAs, one of which co-migrates on SDS-polyacrylamide gels with a relatively abundant cytoplasmic RNA, W1. We purified W1 from ribosome-free high speed supernatant fractions for characterization studies. Electrophoresis under partially denaturing conditions resolves this RNA into several components which bear m ₃ ^{2, 2, 7} G-5′ caps and strongly resemble vertebrate U2 snRNA on the basis of modified nucleotide content. Preliminary sequence analyses indicate that wheat embryos contain at least three U2-like RNAs which possess slightly different sequences near their 3′ ends.