Caste Demography and Aging in Honey Bees

Project: Research project

Description

Social insects provide an ideal model system to study how reproduction, resource flow, and societal status (caste) influences age-specific mortality schedules. Its colony life history and caste structure are simple, with a well-defined differentiation between the reproductive queen and the reproductively quiescent, behaviorally differentiated workers, driven by the availability of food resources. This proposal has four specific experimental aims: 1. determine effects of larval nutrition, ovary size, and reproductive hormones on lifespan; 2. determine effect of adult protein feeding on life history and lifespan; 3. determine direct effects of vitellogenin on lifespan; 4. determine the effect of reproduction on worker mortality and life-course gene expression profiles. The first aim will be met with four experiments involving general nutritive effects, ovary and vitellogenin effects, and ovary and juvenile hormone effects on life history and lifespan. The second aim will be addressed by differential feeding of newly-emerged workers and vitellogenin knock down in a third experimental group. The third aim will target the long-lived diutinus worker caste and in three experiments determine its dependency on reduced brood pheromone levels, juvenile hormone, and vitellogenin, and how the diutinus state affects subsequent lifespan for foragers and hive bees. These experiments will be conducted by a combination of social manipulations, brood pheromone and methoprene (a juvenile hormone analogue) application, and vitellogenin knock-down, using a race of honey bee (Apis mellifera mellifera) that has a pronounced diutinus subcaste. The fourth aim will be achieved in four experiments comparing the mortality dynamics between workers that reproduce and workers that are reproductively inhibited under conditions with brood-rearing, with brood pheromone only, or in total absence of brood, and comparing lifecourse gene expression profiles between reproductive and non-reproductive workers. These experiments will combine social manipulations and brood pheromone application with intensive behavioral observations, demographic censuses, and life-course analysis of gene expression patterns. All described experimental procedures are standard procedures or have already been established in our laboratories.dK
StatusFinished
Effective start/end date9/30/098/31/12

Funding

  • HHS-NIH: National Institute on Aging (NIA): $519,926.00

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brood pheromone
vitellogenin
demography
honey bees
life history
juvenile hormones
gene expression
Apis mellifera mellifera
beehives
methoprene
juvenile hormone analogs
brood rearing
social insects
queen insects
food availability
demographic statistics
hormones
nutrition
proteins