A scientific note defining allelic nomenclature standards for the highly diverse complementary sex-determiner (csd) locus in honey bees.

Authors: Bilodeau, Lanie; ELSIK, CHRISTINE - University Of Missouri

Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2021
Publication Date: 5/6/2021
Citation: Bilodeau, A.L., Elsik, C. 2021. A scientific note defining allelic nomenclature standards for the highly diverse complementary sex-determiner (csd) locus in honey bees.. Apidologie. 58:749-754. https://doi.org/10.1007/s13592-021-00861-x.
DOI: https://doi.org/10.1007/s13592-021-00861-x

Interpretive Summary: Sex determination in honey bees is controlled by a single gene, the complementary sex-determiner (csd). One region of this gene is highly variable (i.e., high numbers of alleles). Variability is important at csd because low diversity within a colony could result in homozygous drones which are sterile, compromising colony brood production. Numerous studies have been published describing diversity at csd and the many alleles that are present, globally. However there has been no collation of csd allelic data or standardized reporting rules. Here, we develop a standardized nomenclature system to describe allelic diversity at the csd locus. The allele set can be found in the centralized hymenoptera genomic database, Hymenopteramine. This will facilitate cross-study comparisons and help to better inform breeding decisions in honey bee breeding programs.

Technical Abstract: Haplodiploid sex determination in honey bees is controlled by the complementary sex-determiner gene. Allelic diversity at csd has been assessed in numerous populations, breeding systems, and subspecies. To date, there has been no synthesis of published csd allele sequences. Here, we assemble and consolidate all of the published csd protein alleles and propose a standardized nomenclature system to normalize csd allele reporting and provide a better global perspective of csd allele diversity. We assembled all published csd allele sequences and defined two common sets of alleles, based on presence/absence of flanking sequence, sequence identity, and frequency in the global population. We recommend usage of standardized nomenclature, using the second defined set of alleles. This set does not use the flanking sequence, but better represents the bulk of published csd allele sequences. Standardized nomenclature for csd alleles will provide a common landscape from which cross-study comparisons can be made, improving our understanding of genetic diversity at the csd locus, on a local and global scale, and will provide insights into the evolution of the gene through identification of common ancestry, in addition to facilitating better-informed breeding decisions.