SISTERS FROM ANOTHER FATHER – CAN HONEY BEE INTRA-COLONIAL DIVERSITY BUFFER THE IMPACT OF DISEASES?

BEAUREPAIRE ALEXIS.; SANN CHRISTINA; ARREDONDO, DANIELA; CASTELLI, LORELEY; GENCHI GARCIA, MARÍA LAURA; REYNALDI FRANCISCO JOSÉ; ANTUNEZ KARINA; MONDET, FANNY; DALMON, ANNE; LE CONTE, YVES

Belgrado

Congreso; 9th European Congress of Apidology; 2022

University of Belgrade ? Faculty of Biology

Honey bees stand amongst the most polyandrous animals, with queens of Apis melliferamating with 16 drones on average. This intra-colonial diversity is expected to enhance theresilience of honey bee colonies towards stressors, but empirical evidence showing thisunder natural conditions remains scarce. We here analyzed the infestation with Varroadestructor and infections with honey bee viruses across A. mellifera patrilines in orderto investigate whether the presence of heterogenous worker genotypes in a honey beecolony can buffer the impact of these important biotic stressors. In a first experiment,we investigated the expression of several phenotypes associated with V. destructoracross A. mellifera worker patrilines: i) infestation of brood, ii) number of foundressesin infested cells, iii) mite reproduction and iv) recapping. To do so, we first phenotyped2627 pupae cells from six colonies for the above-mentioned traits. We then extracted theDNA of 486 of these pupae from three colonies and reconstructed their patrilines usingmicrosatellite markers to compare the observed phenotypes across the different broodgenotypes obtained. The results of this comparison showed no significant variation of theobserved phenotypic traits across the pupae patrilines. In a second experiment, we used108 mite-infested pupae from the same three genotyped colonies to quantify and comparethe genome copies of five honey bee viruses and variants (ABPV, SBV, BQCV, DWV-A andDWV-B) across A. mellifera subfamilies. Only DWV-A and DWV-B were detected in theanalyzed brood samples. Comparing the infestation levels with these two variants revealedsignificant differences across worker brood subfamilies within the colonies. Additionally,DWV-A and DWV-B also exhibited contrasting infection patterns in individual pupae,and showed different temporal infection dynamics. These intra-colonial heterogeneousviral infection patterns stress the need to better incorporate this level of complexity in virus research, and call for more investigations of the molecular mechanisms behind theresistance against these important pathogens. Altogether, the results from these twostudies suggest that high colony genetic diversity can be beneficial against virus infections,but may not help buffering the impacts of V. destructor.