U1 snRNP components are present in the vegetative and generative nuclei of the pollen grain

Abstract

In eucaryotes, the nuclei contain small ribonucleoprotein particles (snRNPs) which mediate splicing of RNA precursors. The male gametophytes of Pinus radiata and Viburnum tinus have more than one U1 snRNA isospecies and some snRNP polypeptides detected by northern and western blotting with probes complementary to tomato U1 snRNA and by protein immunodetection. The snRNP components were localized in both vegetative and generative nuclei of the pollen grain by in situ hybridization and immunocytochemistry. This study suggests that vegetative and generative nuclei contain the splicing apparatus for the post-transcriptional RNA processing in the pollen grain.