Genetic Diversity and Structure in a Closed Breeding System of Russian Honey Bees

High levels of genetic diversity are critical to the success of breeding programs. Russian honey bees are a selected stock that undergoes breeding in a closed block-based mating system. Given its established history, Russian stock has longitudinal measures of genetic integrity (i.e., genetically based stock identity) and diversity. Assessments using genetic stock identification (GSI) have shown that genetic diversity parameters were assessed across breeding blocks for three generations, spanning 6 yr (2014, 2017, and 2020), showing levels comparable to those when the stock was initially released in 2008. Allelic richness (mean number of alleles) and gene diversity levels were consistent over time and among blocks. Blocks were generally not differentiated from one another within each year. However, the 2020 population was distinct when compared with bees sampled in both 2014 and 2017. Genetic distance relationships supported differentiation of the 2020 population by distinct clustering. The patterns observed here are consistent with historical changes made to the breeding program to increase stringency of the selection criteria.

Whole Genome Sequencing and Assembly of the Asian Honey Bee Apis dorsata

The Asian honey bee (Apis dorsata) is distinct from its more widely distributed cousin Apis mellifera by a few key characteristics. Most prominently, A. dorsata, nest in the open by forming a colony clustered around the honeycomb, whereas A. mellifera nest in concealed cavities. Additionally, the worker and reproductive castes are all of the same size in A. dorsata. In order to investigate these differences, we performed whole genome sequencing of A. dorsata using a hybrid Oxford Nanopore and Illumina approach. The 223 Mb genome has an N50 of 35 kb with the largest scaffold of 302 kb. We have found that there are many genes in the dorsata genome that are distinct from other hymenoptera and also large amounts of transposable elements, and we suggest some candidate genes for A. dorsata's exceptional level of defensive aggression.