Vitellogenin, juvenile hormone, insulin signaling, and queen honey bee longevity

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 104; no. 17; pp. 7128 - 7133
• Main Authors: Corona, Miguel, Velarde, Rodrigo A, Remolina, Silvia, Moran-Lauter, Adrienne, Wang, Ying, Hughes, Kimberly A, Robinson, Gene E
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 24.04.2007; National Acad Sciences
• Subjects: Abdomen; Animals; Apis mellifera; Bees; Bees - cytology; Bees - drug effects; Bees - metabolism; Biological Sciences; drone honey bees; Drosophila; Entomology; Fecundity; Fertility; gene expression; gene expression regulation; Gene Expression Regulation - drug effects; Honey; hormonal regulation; Hormones; In Situ Hybridization; Insect Proteins - metabolism; Insulin; Insulin - genetics; Insulin - metabolism; insulin-like growth factor I; Insulin-Like Growth Factor I - genetics; Insulin-Like Growth Factor I - metabolism; juvenile hormones; Juvenile Hormones - metabolism; Life expectancy; Longevity; Longevity - drug effects; Longevity - physiology; messenger RNA; Methoprene - pharmacology; Models, Biological; Organ Specificity - drug effects; Oxidative stress; Oxidative Stress - drug effects; queen honey bees; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction - drug effects; stress tolerance; vitellogenin; Vitellogenins - genetics; Vitellogenins - metabolism; worker honey bees
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0701909104

In most animals, longevity is achieved at the expense of fertility, but queen honey bees do not show this tradeoff. Queens are both long-lived and fertile, whereas workers, derived from the same genome, are both relatively short-lived and normally sterile. It has been suggested, on the basis of results from workers, that vitellogenin (Vg), best known as a yolk protein synthesized in the abdominal fat body, acts as an antioxidant to promote longevity in queen bees. We explored this hypothesis, as well as related roles of insulin-IGF-1 signaling and juvenile hormone. Vg was expressed in thorax and head fat body cells in an age-dependent manner, with old queens showing much higher expression than workers. In contrast, Vg expression in worker head was much lower. Queens also were more resistant to oxidative stress than workers. These results support the hypothesis that caste-specific differences in Vg expression are involved in queen longevity. Consistent with predictions from Drosophila, old queens had lower head expression of insulin-like peptide and its putative receptors than did old workers. Juvenile hormone affected the expression of Vg and insulin-IGF-1 signaling genes in opposite directions. These results suggest that conserved and species-specific mechanisms interact to regulate queen bee longevity without sacrificing fecundity.