180 likes | 276 Views
A new law in genomics ?. Richard Christen CNRS-UNSA UMR 6543 christen@unice.fr. Ci-joint un des articles auquel je pensais pendant ton coup de fil. Amicalement, Jean R. Lobry. Watson Crick. ATCGAGTC. TAGCTCAG.
E N D
A new law in genomics ? Richard Christen CNRS-UNSA UMR 6543 christen@unice.fr
Ci-joint un des articles auquel je pensais pendant ton coup de fil. Amicalement, Jean R. Lobry
Watson Crick ATCGAGTC TAGCTCAG ==> If ATCGAGTC is present in one strand, GACTCGAT is present in the other strand. ==> If a word is present in p copies in one strand its reverse complement is present in p copies in the other strand.
The new rule If a word is present in p copies in one strand its reverse complement is also present in p copies in the same strand. !!!!!!!!
Calculate ratios A k-word AGCGTAGTC present P1 times in a sequence its reverse-complement GACTACGCT present P2 times in same sequence its complement TCGCATCAG present P3 times in same sequence its reverse CTGATGCGA present P4 times in same sequence Lets plot P1/P2, P1/P3, P1/P4 and compare ...
Searching for words ? W= 9 X axis : number of occurrences of a given word Y axis : number of different words with same frequency of occurrence
Searching for words ? Searching for a power law in genomes…. X axis : log(number of occurrences of a given word) Y axis : number of different words with same occurrences
X axis : number of occurrences of a given word Y axis : number of different words with same occurrences ==> 7 categories of words
! Expected : 6.25 if GC%=AT% ==> from the composition of a word, I can predict its frequency !!!
Bacillus subtillis In B. subtilis, comparison on each side of the origin of replication Leading strand versus lagging strand