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Joint Honours in Biology and History & Philosophy of Science
Genetic Basis of Worker Sterility in Honey Bees: knockdown of the Candidate Gene Anarchy1
The honey bee (Apis mellifera) is a model organism for behavioural genetic studies into the evolution of eusociality. In wildtype honey bee colonies the queen monopolises reproduction, while workers are ‘altruistically’ sterile. However, a unique ‘anarchistic’ strain of honey bee is available in which the normally sterile workers activate their ovaries and lay eggs, providing a compelling example of where a ‘cheating’ strategy has invaded a cooperative system.
Both mapping and gene expression studies of the anarchistic strain, have pointed to a recessive locus on chromosome 1 regulating worker sterility. Inspection of this region has yielded a short list of candidate genes. Anarchy1 (GB13621), a solute carrier, is the strongest candidate based on function, differential expression and map location. Anarchy1 is down-regulated in anarchistic workers, relative to wildtype workers; and also in wildtype workers with activated ovaries, relative to those with inactivated ovaries.
My objective is to determine whether the candidate gene, Anarchy1, is causally associated with ovary activation in honey bee workers. RNA interference will be used to knockdown the expression of Anarchy1 in queenless workers and then observe the effect of this knockdown on the reproductive phenotype. Identifying whether or not Anarchy1 is involved in worker sterility is a crucial first step to determining the molecular pathway that regulates functional sterility in honey bee workers, and would be the first example of a kin-selected gene for ‘altruism’ to be characterised at the molecular level.
Philosophy of Biology: Diverse Conceptualisations of 'the Gene'
My thesis is interdisciplinary and contextualises my biological research through a philosophical framework. Genes play a crucial role in contemporary experimental biology. The philosopher and biochemist Lenny Moss claims “that the idea of ‘the gene’ has been the central organising theme of twentieth century biology” (Moss 2003, p. xiii). However, despite the agreement amongst biologists about the fundamental grounding of genetics in DNA both experimentally and ontologically, there is no shared conceptualisation of ‘the gene’. Decades of research and experimental developments in biology have instead led to fragmentation and different conceptualisations of the gene, in different fields of biology, each having heuristic value when used within their own domain. When considering how genes are conceptualised by biologists we should therefore, not aim to arrive at the correct ‘definition’ of the gene but instead explore the causes, and even more importantly the effects, of such varied conceptions. My thesis will investigate the ways that biologists conceptualise genes, in particular: the ‘behavioural gene’, and will clearly demarcate this from other conceptualisations. As part of the analysis a specific case study of the ‘behavioural gene’ will investigate experimental research conducted on anarchistic honey bees. Philosophical and historical research, into how biology is practised and conceived by biologists can help deepen our understanding of the discipline itself and help inform its practice. These points are extremely pertinent to making a case for why my joint Honours thesis will be beneficial for biology itself.