Significant positive correlation between the recombination rate and GC content in the human pseudoautosomal region.
This paper establishes that recombination drives the evolution of GC content in a significant way. Because the human P-arm pseudoautosomal region (PAR1) has been shown to have a high recombination rate, at least 20-fold more frequent than the genomic average of approximately 1 cM/Mb, this region provides an ideal system to study the role of recombination in the evolution of base composition. Nine non-coding regions of PAR1 are analyzed in this study. We have observed a highly significant positive correlation between the recombination rate and GC content (rho = 0.837, p < or = 0.005). Five regions that lie in the distal part of PAR1 are shown to be significantly higher than genomic average divergence. By comparing the intra- and inter-specific AT->GC -GC->AT ratios, we have detected no fixation bias toward GC alleles except for L254915, which has excessive AT-->GC changes in the human lineage. Thus, we conclude that the high GC content of the PAR1 genes better fits the biased gene conversion (BGC) model.
Chen
Jin-Feng
JF
Institute of Bioinformatics, Northwest Agriculture and Forest University, Yangling, Shaanxi, China.
Lu
Fei
F
Chen
Su-Shing
SS
Tao
Shi-Heng
SH
D000818:Animals; D001482:Base Composition / Q000235:genetics*; D022004:Chromosome Structures / Q000737:chemistry*; D004252:DNA Mutational Analysis; D042822:Genomic Instability; D006801:Humans; D032085:Isochores / Q000235:genetics; D009154:Mutation; D002679:Pan troglodytes / Q000235:genetics; D011148:Pongo pygmaeus / Q000235:genetics; D011544:Pseudogenes; D011995:Recombination, Genetic; D013223:Statistics as Topic
D032085:Isochores