At 11:42 17/01/2008, you wrote:
Dear Pedro and Colleagues,some progress has been made in the translation table between 3 times 1_of_4 in a sequence and 20 resp. 21 logical markers being matched to one the other. The next task appears to be to find out the iterations between introns and extrons. Would you please advise me, where to find the collection of observations that details the length and the sequence between introns and extrons.Your coopeartion is highly appreciated. Best Karl
Dear Karl and Colleagues,Sorry for the awful delay, but I am moving to a new research institution (in around two weeks) and my usual disarray has remarkably increased...
It is nice hearing that you have made progress regarding the intron / exon relationship. There exists a vast literature in theoretical biology about the subject, particularly with all those genomes already sequenced. For a taste of the papers see for instance the abstract at the bottom (in my view, the recombination theory to generate new functions they discuss, is a little more interesting). Different eukaryotic species may present rather different data. For humans, exon size mean is 171 nucleotides (standard deviation of 262!, as there is a pretty long tail in the distribution). Concerning the introns of H. sapiens, mean = 124 triplets (around twice the average length of exons thus) with a tail far more extended than the exons (no value of standard deviation was provided in my source). See fine statistics for exons in the paper cited below.
I hope this may help you for a first inspection. best wishes Pedro -------------------------------------------------------------------------------------------------------- Exon size distribution and the origin of intronsSigurbjorg Gudlaugsdottir1 <http://www.springerlink.com/content/17108106305u6r86/#ContactOfAuthor1>
Contact Information , D. Ross Boswell2, Graham R. Wood1 and Jun Ma1(1) Department of Statistics, Macquarie University, North Ryde, Sydney, NSW, 2109, Australia
(2) Middlemore Hospital, Auckland, New Zealand Contact Information Sigurbjorg Gudlaugsdottir Email: <mailto:[EMAIL PROTECTED]>[EMAIL PROTECTED]Received: 12 October 2005 Accepted: 6 January 2007 Published online: 6 February 2007 Abstract Since it was first recognised that eukaryotic genes are fragmented into coding segments (exons) separated by non-coding segments (introns), the reason for this phenomenon has been debated. There are two dominant theories: that the piecewise arrangement of genes allows functional protein domains, represented by exons, to recombine by shuffling to form novel proteins with combinations of functions; or that introns represent parasitic DNA that can infest the eukaryotic genome because it does not interfere grossly with the fitness of its host. Differing distributions of exon lengths are predicted by these two theories. In this paper we examine distributions of exon lengths for six different organisms and find that they offer empirical evidence that both theories may in part be correct.
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============================================= Pedro C. Marijuán Cátedra SAMCA Institute of Engineering Research of Aragon (I3A) Maria de Luna, 3. CPS, Univ. of Zaragoza 50018 Zaragoza, Spain TEL. (34) 976 762761 and 762707, FAX (34) 976 762043 email: [EMAIL PROTECTED] =============================================
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