In article <volker.knoop-1206961143180001 at g2.biologie.uni-ulm.de>, volker.knoop at biologie.uni-ulm.de (Volker Knoop) writes:
|> > I am not aware of any grand consensus about
|> > the origin, original function...
|>|> No, definitely no consensus. What I consider a good working hypothesis is
|> that autocatalytic introns of group I and group II arose in bacteria
|> rather early by chance and may really be considered as selfish sequences.
|> The endosymbiontic bacterial predecessors of mitochondria and chloroplasts
|> may have imported them into the eukaryotic cell. (These introns are
|> present in mitochondria and chloroplasts!!) Group II introns may have
|> invaded the nucleus and have evolved into what you today find as typical
|> eukaryotic spliceosomal introns.
|> Now these latter may indeed have gained later certain functions for
|> example having enhancer functions or by allowing for different products to
|> be made from a single gene via alternative splicing. Exon shuffling is
|> certainly another idea for ascribing function to introns but not so
|> popular any more.
|>|> --
|> Volker Knoop (volker.knoop at biologie.uni-ulm.de)
|> Allgemeine Botanik, Universitaet Ulm, D-89069 Ulm, Germany
|> phone +49-731-502-2615 fax -2626
Any pointers to some recent relevant literature? We have come across a Group I intron in a green algal 18S rDNA more or
less by accident and are intrigued by its possible function and evolutionary origin.
--
H.J. Sluiman (h.sluiman at rbge.org.uk)
Royal Botanic Garden Edinburgh
20A Inverleith Row
Edinburgh EH3 5LR
0131 4590446 x258
