Submitted to: Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/7/1999
Publication Date: N/A
Citation: Interpretive Summary: Genetic mapping is determining on which chromosomes genes controlling various traits, or markers, are grouped and in what order. This provides important information on how these traits are inherited and what genes might control several traits, and is necessary to associate the code sequence of the DNA to specific characteristics. Mapping is done by appropriate matings of individuals that show differences in a trait, such as bees that are very defensive (Africanized), and those that are not (European). This study maps potential locations for genes influencing the production of honey bee sting-associated alarm pheromone with locations for colony defense behavior and marker sequences of the DNA code. The alarm pheromones are chemical signals that are used to initiate and guide colony defense behavior, including stinging. Nine locations were mapped for 5 alarm compounds. They were not associated with genes for colony defense behavior, except for one compound that may reduce stinging behavior. Three locations for a second compound were linked with a gene showing strong influence on body size. The results are unusual in that a single chromosome region seems to influence both biochemical production and behavior, that are themselves related. This information will aid in understanding the ways that biochemistry and behavior may be genetically controlled.
Technical Abstract: QTL mapping procedures were used to identify loci that influence the levels of alarm pheromone found on the sting apparatus of worker honey bees. An F1 queen was produced from a cross between a queen of European origin and a drone descended from an African subspecies. Haploid drones from the hybrid queen were individually backcrossed to sister European queens to produce 172 colonies with backcross workers that were samples by chilling them on ice and removing their stingers. Alarm pheromone levels were determined by gas chromatography. RAPD markers were scored from the haploid drone fathers of these colonies. The multiple-QTL model of MAPQTL was used to identify QTL's that influence the levels of five alarm pheromones. Nine potential loci were identified with LOD scores greater than two: 1 for n-decyl acetate, 2 for n-octanol, 4 for isopentyl acetate, 1- for 2-methyl-1butanol 1 for hexyl acetate. One region of linkage groupss XI shows a a strong influence on body size and level of three alarm pheromones. This locus explained 40% of the variance for the amount of n-decyl acetate (LOD 6.57). In general, the QTLs influencing alarm pheromone levels were independent of previously identified loci that influenced the stinging behavior of these colonies. The single The single exception was a potential locus influencing levels of Results suggest that this compound may reduce stinging behavior.