It is debated if social behavior is controlled at the molecular level by evolutionary novelties or by ancestral regulatory pathways. Our proposal aims to resolve this controversy by testing the reproductive ground-plan hypothesis of social evolution at th e genome level. This universal hypothesis for the origin of social life was proposed by us in 2004, and it has since received considerable international attention. According to the hypothesis, social life evolved via co-option of genes that controlled the reproductive behavioral/physiological cycle of pre-social ancestors. If our proposition is correct, genome regions with genes that contribute to variation in social behavior are also linked to variation in reproductive traits. We will test this specific prediction in selectively bred strains of highly social honey bee (Apis mellifera): an established model in studies of sociality that has repeatedly been used in successful genetic mapping projects.
We will take advantage of the fact that we are at the research forefront in the field of honey bee functional genomics; and in collaboration with USA researchers Dr. Robert E. Page, ASU; and Greg Hunt, Purdue; who are world authorities on genomic mapping of social behavior - and Dr. Stig W. Omholt, Sigbjørn Lien and Paul Berg at Cigene, UMB; use SNP genotyping to map the reproductive traits ovary size and ovary activity onto the bee genome. Resulting genome locations (quantitative trait loci: QTL) will be compared to 4 known genome locations that regulate a documented syndrome of social behavior: social foraging. Candidate genes in the reproductive QTL regions will be identified, verified and functionally tested by cutting-edge techniques, including expression QTL mapping and RNA interference. Genomic/functi onal overlap between reproductive QTL/candidate genes and behavioral QTL/candidate genes will support the reproductive ground-plan hypothesis and provide a first exemplar of the genetic foundations for social life.