Eukaryotic mRNA Intron/Exon Boundary Consensus Sequences?

[DANIEL J. VALE]

roach at u.washington.edu (Jared Roach) writes:

These marking sequences are called consesus sequences. They are actually 
quite a bit longer than two base pairs and the degree of similarity to 
the consensus controlls how efficently the gene is expressed. The 
actually sequences you could look up in a good 2nd yr genetics text like 
'Genetics' by Weaver and Hendrick? (I think thats right but I don't have 
it with me at the moment) Various organisms differ in which bases they 
use in preference when either would do so I imagine that it would vary among 
organisms. 

>	Can anyone point me to a good reference?

>All I know is that functional introns usually begin with GT 
>and end with AG.  Are there known exceptions?  How rare are 
>they?  In short, given a random intron, what is the probability 
>distribution for the composition of its first and last two 
>base pairs? 

>Thanks,  Jared

>EXTRA BONUS QUESTION:  Does this probability distribution 
>depend on the species?


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>Jared C. Roach
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