Annexe 2 Definitions - Dioufamad/SNPs_Calling GitHub Wiki

  • Le genome humain en circos plot :

The human genome is comprised of 22 pairs of chromosomes 1-22 and the pair of sex chromosomes X,Y. Individual chromosomes range from about 50 Mb (chr 21) to about 250 Mb (chr 1) and together compose the 3 Gb human genome.

This graphic shows the chromosomes arranged in a circular orientation, shown as wedges, marked with a length scale. Data placed outside of the chromosome ring represents degree of small- and large- scale variation in the genome at a given position found between different populations.

Data placed on top of the chromosome ring highlights positions of genes implicated in disease, such as cancer, diabetes, and glaucoma. Data placed inside the ring links disease-related genes found in the same biochemical pathway (grey) and the degree of similarity for a subset of the genome (colored).

http://circos.ca/intro/genomic_data/img/circos-conde-nast-large.png

  • Transistions and transversions rates :

the ratio Ts/Tv goes from 1.7 (bird) to 15 (human mitochondria) and grasshooper.

3 mains reasons from transitions being fr superior in numbers in crtains species : 1-transistions are chimically easiest to happen (tautomeric shifts or deamination). 2-natural selection does see reason to remove transitios as if they happen in a codon, theydoesnt change most of the time, the aa coded ex: phenylal can come from (ttc or tta) and glutamine can come from (gaa or gag) for more, see : https://www.quora.com/Why-are-transitions-more-common-than-transversions-in-DNA-mutations