Differential Gene Expression Associated with Honey Bee Grooming Behavior in Response to Varroa Mites

Mollah Md Hamiduzzaman,Subhashree Subramanyam,Christie E Williams,Jennifer M Tsuruda,Greg J Hunt,Ernesto Guzman-Novoa,Berna Emsen

doi:10.1007/s10519-017-9834-6

Mollah Md Hamiduzzaman, Subhashree Subramanyam + Show 5 more

Open Access

https://doi.org/10.1007/s10519-017-9834-6

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Abstract

Honey bee (Apis mellifera) grooming behavior is an important mechanism of resistance against the parasitic mite Varroa destructor. This research was conducted to study associations between grooming behavior and the expression of selected immune, neural, detoxification, developmental and health-related genes. Individual bees tested in a laboratory assay for various levels of grooming behavior in response to V. destructor were also analyzed for gene expression. Intense groomers (IG) were most efficient in that they needed significantly less time to start grooming and fewer grooming attempts to successfully remove mites from their bodies than did light groomers (LG). In addition, the relative abundance of the neurexin-1 mRNA, was significantly higher in IG than in LG, no groomers (NG) or control (bees without mite). The abundance of poly U binding factor kd 68 and cytochrome p450 mRNAs were significantly higher in IG than in control bees. The abundance of hymenoptaecin mRNA was significantly higher in IG than in NG, but it was not different from that of control bees. The abundance of vitellogenin mRNA was not changed by grooming activity. However, the abundance of blue cheese mRNA was significantly reduced in IG compared to LG or NG, but not to control bees. Efficient removal of mites by IG correlated with different gene expression patterns in bees. These results suggest that the level of grooming behavior may be related to the expression pattern of vital honey bee genes. Neurexin-1, in particular, might be useful as a bio-marker for behavioral traits in bees.

Highlights

The parasitic mite Varroa destructor has caused the loss of millions of honey bee (Apis mellifera) colonies and is considered the number one health problem of honey bees worldwide (Stankus 2008; Guzman-Novoa et al 2010; Le Conte et al 2010)
To learn more about genes that may be involved in bee behavioral mechanisms of resistance against mites, we explored the association of different degrees of grooming behavior with mRNA abundance of some candidate genes for which expression information exists for other traits, and from some genes tested for the first time
There were no significant differences in the level of expression of this gene among light groomers (LG), no groomers (NG) and control bees, indicating that only intense grooming was associated with a high expression level of AmNrx1 (F3, 48 = 12.20, p < 0.0001, Fig. 3a)

Summary

Introduction

The parasitic mite Varroa destructor has caused the loss of millions of honey bee (Apis mellifera) colonies and is considered the number one health problem of honey bees worldwide (Stankus 2008; Guzman-Novoa et al 2010; Le Conte et al 2010). Most beekeepers use synthetic miticides to control the parasites, but the continuous use of pesticides leads to the development of resistance in the mites (Milani 1999). One potential approach to controlling V. destructor would be the development of honey bee strains resistant to the parasite. This could theoretically be achieved by natural selection (bees not treated against the mite) or by breeding bees expressing traits associated to mite resistance or tolerance (Rinderer et al 2010; Arechavaleta-Velasco et al 2012; Guzman-Novoa et al 2012; Hunt et al 2016)

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