Comparative Physiological and Genomic Analyses of Division of Labor in Honey Bees and Paper Wasps

"This thesis describes research aimed at understanding the mechanisms and evolution of sociality in colony-forming insects. I first summarize a conceptual framework for the study of social behavior inspired by the field of evolutionary developmental biology (""evo-devo""); I suggest complex social behavior evolves via co-option of mechanisms underlying basic forms of solitary behavior, such as feeding and reproduction. Next, I describe research with honey bees (Apis mellifera) to determine whether division of labor between workers is related to individual nutritional status. I found that bees performing foraging behavior have half the abdominal lipid stores of hive-workers. Then, I demonstrated experimental lipid depletion causes early onset of foraging, suggesting that a change in nutritional status can have a causal influence on behavior. Additionally, my results show that social interactions between workers are necessary for bees to attain high lipid stores as found in hive-workers, but that social interactions and nutrition act independently to influence foraging ontogeny. Because a nutritionally-depleted foraging force characterizes many social insect species, I investigated whether the nutritional mechanism and other molecular pathways influencing division of labor are conserved in an insect with independently evolved sociality, the paper wasp Polistes metricus. I also found low abdominal lipid in P. metricus foragers. I then developed an EST project of sequences representing approximately 5000 P. metricus genes. I examined the expression of a set of 32 P. metricus orthologs to genes known from previous studies to be associated with foraging behavior in worker honey bees. I found that expression of this set of genes differed significantly between P. metricus females in distinct behavioral castes. Expression patterns of individual wasps were predictive of behavioral state with a high (up to 80%) rate of success. In addition, I found 34% of genes to be associated with differences in wasp foraging state. In summary, I have demonstrated shared patterns of physiological and molecular regulation of social organization in two species with widely different forms of sociality. These results suggest several shared mechanisms underlying multiple origins of sociality and hint at the existence of a shared genetic ""toolkit"" for the evolution of social organization."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Toth, Amy Lynn

Contributors dc:contributor

• Robinson, Gene E.

• Biology, Neuroscience

Language dc:language

eng

Identifier

(MiAaPQ)AAI3250335

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85368