A reduced NCO gene conversion rate
One domain shines as a beneficial recombinational desert. No CO otherwise gene conversion enjoy try perceived into the an about 400 kb region nearby the two linked gender dedication family genes, csd and you can fem (More file 1: Contour S14). We suggest that, just like the heterozygosity off csd find new gender out of honeybee [56,57] and you can diploid homozygotes try sterile people, gene transformation contained in this domain could well be disadvantageous. Because the gene conversion are associated each other with CO and you may NCO situations, all of the recombination is abolished to cease homogenization. An absence of recombination as well as forces the 2 loci to behave as one haplotype.
Our influence really stands within the striking examine to an earlier claim that receive excessively large CO rates in the https://datingranking.net/hiki-review/ vicinity of the fresh new csd locus. A potential quality of inconsistent states would be the fact while in the newest quick area of family genes there isn’t any recombination, this can be counterbalanced from the strangely large prices in the covers proximal towards desert. A lower life expectancy resolution studies do choose the greater prices throughout the covers. Consistent with it i observe a leading level of recombination in the this new quick vicinity of the plateau (Extra file step 1: Shape S14).
Talk
All of our investigation add to the understanding one to public hymenoptera has actually both highest and you may extremely changeable crossing-more rates. In fact, the rate ranged ranging from 0 and you may 197 cM/Mb when measured in non-overlapping 2 hundred kb windows round the chromosomes (Contour step three, Figure S8 during the More document step 1 and Dining table S6 from inside the Extra document 2), indicating the brand new very bumpy shipping out-of crossovers on genome. This new profile out of 37 cM/Mb, while you are higher for animals, has been less than you to seen for some fungi and protozoans, in which cost in excess of 60 cM/Mb are reported . To your best of all of our training, this new guess indicates a top crossing-over price than simply seen in one bush 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.
