Author
AMDAM, GRO - Arizona State University | |
PAGE, ROBERT - Arizona State University | |
FONDRK, KIM - Arizona State University | |
Brent, Colin |
Submitted to: Proceedings of the National Academy of Sciences (PNAS)
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/28/2010 Publication Date: 9/23/2010 Citation: Brent, Colin, Amdam, Gro, Page, Robert Jr., and Fondrk, M Kim. (2010) Hormone response to bidrectional selection on social behavior. Evolution and Development. Wiley Periodicals. Vol. 12, N 5 Interpretive Summary: Honey bees (Apis mellifera) exhibit variation in the development of their complex social behaviors. These effects can result from altered hormonal systems that, as life-long regulators of multiple cellular activities, affect phenotypes expressed during different life-stages. It is not well understood, however, how variation in the social behavior of adult bees is influenced by early developmental processes. Here, we study two honey bee strains selectively bred for adult food storage behavior. We document strain-specific differences between individuals during larval, pupal, and early adult life-stages for the central insect hormones juvenile hormone (JH) and ecdysteroids. These differences correlate with the differentiation of female reproductive anatomy (ovary size) that is induced by JH during larval stages, secretion of ecdysteroid from the ovaries of young adults, and variation in foraging behavior that is linked to the size of ovaries. Our findings show for the first time that the ovaries of honey bees can be directly responsible for variation in hormonal signals, and strongly suggest that artificial selection for foraging behavior has acted on genes with effects on early developmental processes. Technical Abstract: Behavior is a quantitative trait determined through the actions of multiple genes. These genes form pleiotropic networks that are sensitive to environmental variation and genetic background. One aspect of behavioral gene networks that is of special interest includes effects during early development. These effects can result from altered hormonal systems that, as life-long regulators of multiple cellular activities, affect phenotypes expressed during different life-stages. To understand such complex suits of traits, it is desirable to minimize environmental variation and essential to control genetic background. Honey bees (Apis mellifera) can be used to fulfill these requirements, and have been used in experiments on the genetic and hormonal control of social behavior. Is not well understood, however, how variation in the social behavior of adult bees is influenced by early developmental processes. Here, we study two honey bee strains selectively bred for adult food storage behavior. We document strain-specific differences between individuals during larval, pupal, and early adult life-stages for the central insect hormones juvenile hormone (JH) and ecdysteroids. These differences correlate with the differentiation of female reproductive anatomy (ovary size) that is induced by JH during larval stages, secretion of ecdysteroid from the ovaries of young adults, and variation in foraging behavior that is linked to the size of ovaries. Our findings show for the first time that the ovaries of honey bees can be directly responsible for variation in hormonal signals, and strongly suggest that artificial selection for foraging behavior has acted on gene networks with effects on early developmental processes. |