A minimal NCO gene conversion rate
One domain name stands out as the a great recombinational desert. Zero CO otherwise gene conversion process feel is thought when you look at the an approximately 400 kb part surrounding the two connected gender determination genes, csd and you may fem (Additional document step 1: Profile S14). We suggest that, since the heterozygosity off csd determines this new sex from honeybee [56,57] and you may diploid homozygotes are sterile boys, gene conversion process in this domain name would be disadvantageous. Since gene sales was related one another with CO and you will NCO occurrences, all recombination can be abolished to end homogenization. A lack of recombination along with forces the 2 loci to do something since just one haplotype.
Our very own result stands inside the striking compare to an early on report that located acutely high CO rates near the latest csd locus. A prospective solution of your own inconsistent states is that whilst in the fresh new instant location of your genetics there’s absolutely no recombination, this might be counterbalanced from the surprisingly high cost regarding spans proximal on the wasteland. Less solution studies would select the higher rates regarding spans. In keeping with this i to see a top height away from recombination within the the fresh instant area of one’s plateau (Extra file step one: Profile S14).
The data enhance the understanding you to societal hymenoptera features each other higher and you will extremely changeable crossing-more rates. In reality, the speed ranged anywhere between 0 and you may 197 cM/Mb whenever measured inside low-overlapping 2 hundred kb screen across the chromosomes (Contour 3, Shape S8 into the Most file step one and Desk S6 from inside the Even more document 2), recommending new highly uneven shipment out-of crossovers on genome. The fresh new profile off 37 cM/Mb, if you’re higher for pets, is still less than that seen for most fungus and protozoans, where cost more than sixty cM/Mb is actually claimed . Towards the is glint free best of our studies, this new estimate implies increased crossing-over rate than simply seen in people plant otherwise animal.
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.