Reverse Genetics

One approach for finding behavioural genes is to first develop a short-list of candidates, usually with reference to their known or presumed function in another organism. The candidate genes are then tested, to the exclusion of other genes, for involvement in the behaviour. Though selective in terms of loci screened, this 'reverse genetic' strategy is expedient, and makes use of the fact that a gene's molecular function tends to be conserved across taxa. Thus, information regarding gene function in one taxon (e.g. Drosophila) can be exported to another taxon (e.g. Apis), at least provisionally.

One example of a targeted screen involved testing malvolio (mvl) as a contributing factor affecting foraging behaviour in honey bee workers (Ben-Shahar et al., 2004). In this study, mvl was chosen as a candidate because, as a manganese transporter, it is known to influence responsiveness to sucrose in Drosophila, and variation in sucrose response among individuals is known to influence foraging-related task-specialization in honey bees (see Section 4.3.2). Ben-Shahar and colleagues showed that the levels of mvl mRNA in the brain cells of workers are strongly associated with differences in worker foraging activity: pollen foragers tend to have higher levels of mvl transcript than nectar foragers and foragers of either type have higher levels than do non-foraging nurse bees. It appears that some feeding-related genes in Drosophila are also related to feeding in Apis, and in the case of honey bees may be related to age-based task specialization.

The association between gene expression and behaviour is sufficiently strong for these authors to suggest that mvl is a component in a molecular pathway linking a worker's perception of food quality to division of labour within the colony. This is an example of a gene conserved in function from a distantly related (approximately 300 MY) non-social taxon affecting, or is at least correlated with, variation in honey bee behaviour. In the Drosophila-Apis case, the mvl and also for gene (Ben-Shahar et al., 2002) appear to have something to do with the regulation of foraging behaviour, but their precise role or importance is not yet known with certainty (Rueppell et al., 2004a). The important task of expanding this type of single-locus genetic information to a complete molecular pathway will be the next step. However, we mentioned this example here because it shows that, in general, the candidate gene approach (Fitzpatrick et al., 2005) has promise in behavioural genetics - despite the fact that it is restricted only to those genes that are conserved from other model taxa.

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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