||Fruit fly Drosophila melanogaster
||Audibert A, Weil D, Dautry F. In vivo kinetics of mRNA splicing and transport in mammalian cells. Mol Cell Biol. 2002 Oct22(19):6706-18. doi: 10.1128/MCB.22.19.6706-6718.2002 p.6706 right column 2nd paragraphPubMed ID12215528
||Beyer, A. L., and Y. N. Osheim. 1988. Splice site selection, rate of splicing, and alternative splicing on nascent transcripts. Genes Dev. 2: 754-765.PubMed ID3138163
||P.6706 right column 2nd paragraph:"Although the biochemical analysis of splicing has greatly benefited from the existence of an in vitro splicing system, it is obvious that the limited efficiency of the system and its very slow kinetics cannot reflect the characteristics of splicing in vivo. In intact cells, splicing rates for various introns have been derived from pre-mRNA half-lives following arrest of transcription (refs 8, 11, 44). This approach does not allow determination of whether the measured half-life is due to splicing or degradation or a combination of both. Moreover, the transcription block is often achieved with a general inhibitor of transcription, which may affect the cellular physiology. Direct visualization of introns can be achieved in some cases by electronic microscopy and, by comparison with the elongation of transcription, it can be used to estimate a minimal time required for cotranscriptional splicing. In Drosophila melanogaster, this approach yielded an estimate of about 3 min (primary source)."