Genetic and behavioural basis of social organisms-parasite interactions: the case of honeybees and the mite varroa destructor

点击翻译按钮获取中文摘要

The goal of this project is to generate new basic knowledge about the genetic and behavioural mechanisms that regulate the populations of a parasite affecting a social organism. Honeybees are good models of social organisms because of the large number of individuals in their colonies, their well-known division of labour, and the existence of technology to manipulate their environment and to study their genetics and behaviour. The mite Varroa destructor is a relatively new parasite of Apis mellifera (less than 60 years of interaction) and therefore it is generally highly pathogenic to its new host. Variability in its detrimental effects to honeybee colonies is well documented, but the causes of this variability are not yet well understood. It is known that bees posses behavioural mechanisms of resistance or tolerance against the mite, but the genetic basis underlying the expression of these mechanisms, as well as their relative impact on restraining the mite population growth is not well known. We will amplify DNA markers linked to quantitative trait loci (my collaborator G.J. Hunt has sequenced cDNA from genes that influence bee behaviours and developed primers and restriction enzyme combinations that reveal polymorphisms within the genes) from individual workers sampled when performing hygienic behaviour (the ability of bees to detect, open a cell, and discard bee brood infested with mites) and grooming behaviour (the ability of workers to dislodge mites from their bodies and/or injure them), to determine if they influence these behavioural characteristics. We will also document genetic effects on mite fertility and rates of mite population growth, as well as the genotypic variability, mode of inheritance, and relative impact of these two mechanisms. Additionally, we will further study the relationship between the above behaviours and defensive behaviour (we have preliminary data on this regard). We are interested in pleiotropic gene effects for grooming, hygienic, and defensive traits. We have ample experience in behavioural and genetic studies conducted with honeybees and Varroa mites. Therefore, this study has very high probabilities of being completed successfully.