The best crossover rates found in dogs and you may plants Leave a comment
One to domain name stands out as an excellent recombinational wasteland. Zero CO otherwise gene sales enjoy is actually recognized inside an around 400 kb part nearby the two connected sex commitment genetics, csd and fem (Extra file step one: Figure S14). I advise that, given that heterozygosity of csd find new sex from honeybee [56,57] and you can diploid homozygotes is sterile boys, gene transformation inside domain name would be disadvantageous. Given that gene transformation is actually related both with CO and NCO occurrences, every recombination is abolished to end homogenization. An absence of recombination together with pushes both loci to act since the just one haplotype.
All of our result really stands inside the hitting contrast in order to an early claim that receive exceedingly large CO rates in the vicinity of the newest csd locus. A possible solution of the inconsistent says is that while in the brand new instantaneous location of your own genes there’s no recombination, this is exactly counterbalanced by the unusually high cost regarding the spans proximal to your wasteland. A reduced resolution analysis manage detect the greater costs from the spans. Consistent with so it i to see a premier hookup bars Belleville level regarding recombination inside the the fresh immediate area of your plateau (A lot more file 1: Shape S14).
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Our data add to the sense you to definitely personal hymenoptera has actually both highest and you can very changeable crossing-more than rates. In reality, the rate varied ranging from 0 and you may 197 cM/Mb when mentioned for the low-overlapping two hundred kb window around the chromosomes (Profile 3, Profile S8 within the Most document step one and you may Table S6 inside Additional file 2), recommending the brand new highly rough shipment from crossovers throughout the genome. New contour of 37 cM/Mb, whenever you are highest having pets, has been less than one viewed for the majority fungus and you can protozoans, where prices over sixty cM/Mb try reported . To the good all of our knowledge, brand new estimate ways increased crossing-over price than found in one bush or animal.
A minimal NCO gene rate of conversion
While our study finds evidence consistent with several theoretical predictions, cause and effect are always hard to disentangle from correlation alone. For example, in principle the diversity/crossing-over coupling is also consistent with the notion that crossing over occurs preferentially in domains of high diversity and with the notion that crossing over is mutagenic . Similarly, the correlation between recombination rate and GC content is consistent with both the possibility that crossing over forces a high GC content and with the possibility that a high GC content favors increased crossing over. The conventional wisdom holds that recombination forces heteroduplexes within which mismatches require resolution. If this resolution is biased towards G and C residues (biased gene conversion), then a correlation between GC and recombination rate is expected . Previous analyses in honey bee have demonstrated fixation biases toward GC in high recombination parts of the genome . Evidence to support this direction for the causal arrow requires SNP analysis showing a bias to AT- > GC SNPs being fixed (or otherwise favored) compared to GC- > AT SNPs at sites of recombination. The key events here are most probably crossover-associated gene conversion events, but for these we cannot determine the direction of conversion and we are likely to be missing the majority of them. In our identified NCO events, if u is the number of AT > GC SNPs per A or T and v is the number of GC > AT SNPs per G or C, then the ratio of u/v is 1.06, which is slightly greater than the null (from stochastic simulations with 10,000 repeats: P <0.08). Being on the edge of significance, we cannot robustly say that NCO is or is not associated with GC-biased gene conversion.
