Given the correlation noted above between high gene density and low crossing-over rates, perhaps the association with worker brains simply reflects their residing in domains of low density? The gene density across the whole genome is 4.1 genes/100 kb. Surprisingly, then worker-brain-biased genes reside in regions of higher gene density, averaging 9.0 genes/100 kb, and so, all else being equal, should have low crossing-over rates. Indeed, when compared with other genes from domains of similar gene density, worker-brain bias genes are very highly enriched near COs (chi sq-test, P <2.2e-16: for worker-brain-bias genes vs. for genes in similar gene density). The correspondence with high gene density is not simply a consequence of tandem gene duplication favoring worker-brain-biased genes. Of 752 worker genes 701 are single copy genes (query and hit with overlapping region >50% and identity >50% are treated as paralogs). These singletons are closer (<10 kb) to recombination hotspots than expected by chance (P <1e-9 in chi square-test, method as in Table S8) and in domains of high density (9 genes/100 kb). These results provide prima facie support for the hypothesis that selection favors the higher recombination rate in worker brain genes.
Comparable efficiency had been along with present in regions that have copy count variations, in a manner that the genes having staff member-mind biased term compared with queen’s otherwise drone’s brain are highly of the content count variations (Dining table S8B and you can S8C inside Most document 2). By comparison the fresh new drone-brain-biased term family genes (defined when comparing to worker’s notice) are rather missing from all of these countries (Table S8B and you may S8C when you look at the Extra document 2). This will be perhaps as sure-enough given that CNV nations will most likely be also the result of recombination (thru uneven crossover ). A few of these multi-duplicate places ought to be the result of unequal CO mainly because multi-duplicates is apparently hookup Edmonton combination duplications on genome inferred out of the fresh new romantic point (1 kb-5 kb) involving the paired-end reads.
Good coupling between crossing over and you can brain term is also advised by research regarding genetics with better-demonstrated functions. At breakpoint spot regions of COs, you will find 42 really-annotated genetics, whose means is confirmed regarding the honeybee otherwise fruits fly. Remarkably, 17 ones, together with half dozen worker-brain-biased expression genes, have properties from the nervous system otherwise decisions (Desk S9 in the Additional document 2).
Intercourse commitment genes come into a great recombinational desert
Interpretation of more than performance will get yet become difficult. Regarding the person genome, a bold bad correlation ranging from within this-gene CO price and you can phrase depth could have been noticed . Might it be one to a biased term in staff thoughts just is actually an indication regarding better cells specificity which means that higher crossing-over prices? Immediately after viewing the EST investigation and you will healthy protein atlas inside the organs and you can frameworks off bees, i are not able to locate one trend relating term breadth to help you CO costs (spearman rho = -0.036, P = 0.twelve, N = step 1,874). It will be you to germline phrase for the queens is exactly what things, if so depth away from term from inside the queens may be the key adjustable. Although not, depth from term during the queens is also not related toward CO rate: rho = -0.073, P = 0.twenty-eight, N = step one,727.
No proof one to protected genetics keeps strange crossing-over speed
Various other tip getting large recombination cost implies good parasite driven pressure . Inside the 150 immune-associated family genes annotated in the Evans’ study , commonly genes during the Toll, Imd, and you may JAK/STAT paths, twenty-seven of them can be found near a good CO breakpoint (length ? 10 kb). This is not notably different to what would be anticipated to possess a random gene (Chi squared P >0.05).