A Genetic Analysis of the Stinging and Guarding Behaviors of the Honey Bee

Abstract

In order to identify genes that are influencing defensive behaviors, we have taken a new approach by dissecting colony-level defensive behavior into individual behavioral measurements using two families containing backcross workers from matings involving European and Africanized bees. We removed the social context from stinging behavior by using a laboratory assay to measure the stinging response of individual bees. A mild shock was given to bees using a constant-current stimulator. The time it took bees to sting in response to this stimulus was recorded. In addition, bees that were seen performing guard behaviors at the hive entrance were collected. We performed QTL mapping in two backcross families with SNP probes within genes and identified two new QTL regions for stinging behavior and another QTL region for guarding behavior. We also identified several candidate genes involved in neural signaling, neural development and muscle development that may be influencing stinging and guarding behaviors. The lack of overlap between these regions and previous defensive behavior QTL underscores the complexity of this behavior and increases our understanding of its genetic architecture.

Biased Allele Expression and Aggression in Hybrid Honeybees may be Influenced by Inappropriate Nuclear-Cytoplasmic Signaling

“…It is possible that there is an inversion in these regions in the AHB lineage resulting in this pattern of expression bias, but we are unable to test for this due to low coverage of our genomic DNA from this lineage. This possibility seems unlikely, however, as we would expect to see a comparable reduction in Africanized (i.e., maternal) expression in the AE family in these regions and previous independent studies of recombination in EA hybrids haven’t indicated the expected loss of recombination within these regions ( Hunt et al, 1998 ; Shorter et al, 2012 ; Ross et al, 2015 ). Given the size of these clusters (∼500 kb) and the near complete silencing of the paternal alleles across tissues and life stages it seems likely that differential chromatin modifications in the homologous chromosomes contribute to this asymmetric pattern.…”

“…We tested the stinging behavior of individual bees from our crosses by measuring the time that each bee took to sting a black suede patch after being stimulated with electrical current (assay described in Shorter et al, 2012 ). In total 573 bees were tested from the four F1 reciprocal colonies.…”

“…We assessed whether genes showing asymmetric maternal PSGE lie within QTL influencing traits related to colony defense ( Hunt et al, 1998 , 1999 , 2007 ; Arechavaleta-Velasco et al, 2003 ; Shorter et al, 2012 ), reproduction ( Oxley et al, 2008 ; Linksvayer et al, 2009 ; Rueppell et al, 2011 ), and pollen foraging behavior ( Hunt et al, 1995 , 2007 ; Page et al, 2000 ). We used the diagnostic SNPs within biased genes to determine their location in the Amel4.5 assembly.…”

Do social insects support Haig's kin theory for the evolution of genomic imprinting?

“…Differences in worker ovary size and stinging behavior in A. mellifera show strong parent-of-origin effects 132,133 suggesting that an imprinting mechanism may be in place.…”

“…Africanised honeybees ( Apis mellifera scutellata ) are known to exhibit a more rapid stinging response to alarm stimuli (visual or pheromonal), that is more sensitive, with a lower threshold before initiating a sting response, compared with the European subspecies. 132 Through backcrossing and reciprocal cross studies this defensive behavior has been correlated with paternal inheritance. Drones from F1 queens of a cross of Africanised drones and European queens were used for backcrosses in Stort and Goncalves' study which found increased defensive behaviors in backcross colonies.…”