Marker-assisted selection (MAS) uses DNA markers — short repeated sequences (microsatellites) or single nucleotide changes (SNPs) — that sit near or inside a gene of interest. Because the marker and the gene are inherited together, a breeder can genotype a young larva or a drone and know its likely genetic merit for a trait such as Varroa resistance long before that trait could ever be observed in an adult colony.
Because drones are haploid (they develop from unfertilised eggs), a single drone carries only one copy of each allele — which makes honey bee marker analysis unusually clean compared to diploid livestock, and is part of why MAS caught on quickly in bee breeding programmes for traits like Varroa sensitive hygiene (VSH).
A rotating DNA double helix marks the genotyping assay while a live honey bee pedigree — one queen, a drone pool, and eight daughters — shows how a single marker locus lets breeders sort favourable genotypes before any trait is ever observed in the colony.
Each daughter inherits one allele from the queen and one haploid allele from a drone. Colour-coded genotypes (green/amber/red) show exactly what a marker test would report, and raising selection intensity culls low-scoring daughters before they can be observed as adults.
Pick a marker type, set the drone pool's favourable-allele frequency and the selection intensity, then click Advance Generation to mate the best daughter forward and watch the pedigree and glowing marker locus update.
Because drone bees are haploid, they carry only one copy of each allele — making marker genotyping in honey bees unusually unambiguous compared with diploid livestock breeding.