Abstract (EN):
Evidence for selection on human mtDNA has been obtained from the results of some widely used tests: (a) higher replacement (R) to synonymous (S) substitution ratios in human genes ND2, CO1, ATP6, CO3 and CytB (and overall) than expected by human/chimpanzee comparisons; (b) distributions of absolute (K/(K+S)) and corrected (for coding degeneracy; Ka/(Ka+Ks)) frequencies for R are heterogeneous for human mtDNA genes (higher for ATP6, ATP8 and CytB); and (c) no correlation between gene length-R (in opposition to gene length-S). However, a mere 8.3% of sequences show R/(R + S) greater than or equal to 0.5 and, furthermore, R/S ratio is strongly correlated with haplogroup classification based on HVR variability. Demographic history seems therefore enough to explain the observed diversity in human mtDNA coding region, with older haplogroups showing lower R/S ratios than younger ones.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
3