Mammalian Exon Size: Upper Limit
robison1 at husc10.harvard.edu
Wed Jun 10 11:12:08 EST 1992
khofmann at biomed.biolan.uni-koeln.de writes:
>Looking at the current query for the biggest internal exon, another question
>comes to my mind:
>What is the size of the smallest introns found in higher eukaryotes?
>I would imagine that, considering current knowledge of the splicing
>process, there should be a definitive lower limit for intron lengths.
A _very cursory_ check of the plant division of GenBank finds a
15 bp intron in the major latex protein gene from poppy(PAPMLG X54306).
I don't know whether to believe this. A number of introns in plants
appear to be in the 40's.
>or, more generalized, where do those kind people who answer those questions
>get their figures from? Is there any kind of computer program available,
>scanning the databases and giving information of the type mentioned above?
I am using a local copy of GenBank 71 and some custom software designed
for extracting reading frames from multi-exon genes in GenBank*, plus
some UNIX manipulations. It worked well for the original "biggest exon"
query, and not so well for this one.
>I remember several examples of 'what is the biggest....' questions on the
>net over the past few years. Perhaps someone should publish a Guiness-File of
>molecular biology, holding entries like: the biggest or smallest intron or
>exons ever, the biggest/smallest genomes, or, as already asked in the past,
>the biggest insert ever cloned into pUC. :-)
Program in Biochemistry, Molecular, Cellular, and Developmental Biology
robison at ribo.harvard.edu
* -- software available upon request. Users must be willing to put
up with a high level of idiosyncrasity and a moderate level
of user hostility :-)
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