The First Draft Genome of the Plasterer Bee Colletes gigas (Hymenoptera: Colletidae: Colletes)

摘要

Despite intense interest in bees, no genomes are available for the bee family Colletidae. , one of the largest species of the genus in the world, is an ideal candidate to fill this gap. Endemic to China, has been the focus of studies on its nesting biology and pollination of the economically important oil tree , which is chemically defended. To enable deeper study of its biology, we sequenced the whole genome of using single-molecule real-time sequencing on the Pacific Bioscience Sequel platform. In total, 40.58 G (150×) of long reads were generated and the final assembly of 326 scaffolds was 273.06 Mb with a N50 length of 8.11 Mb, which captured 94.4% complete Benchmarking Universal Single-Copy Orthologs. We predicted 11,016 protein-coding genes, of which 98.50% and 84.75% were supported by protein- and transcriptome-based evidence, respectively. In addition, we identified 26.27% of repeats and 870 noncoding RNAs. The bee phylogeny with this newly sequenced colletid genome is consistent with available results, supporting Colletidae as sister to Halictidae when Stenotritidae is not included. Gene family evolution analyses identified 9,069 gene families, of which 70 experienced significant expansions (33 families) or contractions (37 families), and it appears that olfactory receptors and carboxylesterase may be involved in specializing on and detoxifying pollen. Our high-quality draft genome for lays the foundation for insights on the biology and behavior of this species, including its evolutionary history, nesting biology, and interactions with the plant .