Coupling of transcription and translation in Dictyostelium discoideum nuclei

The nuclei of Dictyostelium discoideum cells have been found to contain pol yribosomes active in protein synthesis. mRNA molecules enter nuclear polyri bosomes while they are still being synthesized. "Non sense mediated mRNA de cay" occurs in the nucleus, through the interaction of the mRNAs containing a nonsense codon with newly formed nuclear ribosomes, rather than with cyt oplasmic ribosomes, as previously generally supposed.