Genomic synteny and comparison of recombination between Apis mellifera (the European honey bee) and Apis florea (the red dwarf honey bee).

摘要

In all sexually reproducing organisms meiotic recombination increases genetic diversity among offspring and creates new genomes through chromosomal reconfiguration. The rate at which recombination occurs varies among and within species. Recombination rates are exceptionally high in social insect species and the European honey bee (Apis mellifera) has the highest recombination rate known in multi-cellular eukaryotes. To explain this, three major, non-exclusive hypotheses have been proposed. High recombination may be the result of strong selection during domestication of the honey bee (1). Alternatively, it may benefit division of labor (2) or disease resistance (3) by increasing the genetic diversity among colony members. Therefore, I compared the genomic recombination rate in Apis mellifera to that of A. florea (the red dwarf honey bee). This species is undomesticated, has a relatively low degree of pathogen pressure and a complex division of labor. I screened 684 microsatellite markers from the A. mellifera genome for polymorphism in A. florea ; 37 polymorphic markers were identified and genotyped in a mapping population of 96 A. florea drones. Pairwise recombinational distances were calculated using MapMaker3.0. I examined genomic synteny over two chromosomes, finding marker order conserved in both. Overall recombination distances are comparable between the species, though I found one interval of significantly higher recombinational distances in A. florea and no intervals of significantly lower distances. I conclude that the high recombination rate in A. mellifera is not a result of domestication and provide further support for the link between complex division of labor and high recombination rate.