Maize transposable element Ds is differentially spliced from primary transcripts in endosperm and suspension cells

The process by which transposable elements are spliced from the host gene t ranscripts remains poorly understood. We previously reported that a maize t ransposable element Ds (dissociation) and a copy of its host site duplicati on are perfectly spliced from the shrunken-2 transcript in the endosperm. H ere, we have monitored splicing of the Ds element and its flanking Sh2 sequ ence following transient expression in maize suspension cells. The pattern of Ds splicing in suspension cells differs dramatically from that in the en dosperm. In contrast to splicing in the endosperm, Ds in suspension cells w as completely spliced from the transcripts using multiple donor and accepto r splice sites outside the element. In addition, noncanonical splice sites were utilized in suspension cells. Our results indicate that this differenc e in splicing is due to the context of Ds placement in the construct and/or to tissue specific differences in splicing. (C) 1999 Academic Press.