<Table> <Tr> <Td> </Td> <Td> This article may be too technical for most readers to understand . Please help improve it to make it understandable to non-experts, without removing the technical details . (December 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article may be too technical for most readers to understand . Please help improve it to make it understandable to non-experts, without removing the technical details . (December 2016) (Learn how and when to remove this template message) </Td> </Tr> <P> In molecular biology, splicing is the editing of the nascent precursor messenger RNA (pre-mRNA) transcript into a mature messenger RNA (mRNA). After splicing, introns are removed and exons are joined together (ligated). For nuclear - encoded genes, splicing takes place within the nucleus either during or immediately after transcription . For those eukaryotic genes that contain introns, splicing is usually required in order to create an mRNA molecule that can be translated into protein . For many eukaryotic introns, splicing is carried out in a series of reactions which are catalyzed by the spliceosome, a complex of snRNPs . Self - splicing introns, or ribozymes capable of catalyzing their own excision from their parent RNA molecule, also exist . </P> <P> Several methods of RNA splicing occur in nature; the type of splicing depends on the structure of the spliced intron and the catalysts required for splicing to occur . </P>

Where does pre mrna splicing occur in eukaryotes