RNAi-mediated silencing of vitellogenin gene function turns honeybee (Apis mellifera) workers into extremely precocious foragers

Author(s)

Marco Antonio, David Santos ^[1] ; Guidugli-Lazzarini, Karina Rosa ^[2] ; do Nascimento, Adriana Mendes ^[2] ; Paulino Simoes, Zila Luz ^[2] ; Hartfelder, Klaus ^[3]

Affiliation

^[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Genet, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Pret, Dept Biol, BR-14049900 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Biol Celular & Mol & Bioagentes Patogen, BR-14049900 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: NATURWISSENSCHAFTEN; v. 95, n. 10, p. 953-961, OCT 2008.
• Web of Science Citations: 65

Abstract

The switch from within-hive activities to foraging behavior is a major transition in the life cycle of a honeybee (Apis mellifera) worker. A prominent regulatory role in this switch has long been attributed to juvenile hormone (JH), but recent evidence also points to the yolk precursor protein vitellogenin as a major player in behavioral development. In the present study, we injected vitellogenin double-stranded RNA (dsVg) into newly emerged worker bees of Africanized genetic origin and introduced them together with controls into observation hives to record flight behavior. RNA interference-mediated silencing of vitellogenin gene function shifted the onset of long-duration flights (> 10 min) to earlier in life (by 3-4 days) when compared with sham and untreated control bees. In fact, dsVg bees were observed conducting such flights extremely precociously, when only 3 days old. Short-duration flights (< 10 min), which bees usually perform for orientation and cleaning, were not affected. Additionally, we found that the JH titer in dsVg bees collected after 7 days was not significantly different from the controls. The finding that depletion of the vitellogenin titer can drive young bees to become extremely precocious foragers could imply that vitellogenin is the primary switch signal. At this young age, downregulation of vitellogenin gene activity apparently had little effect on the JH titer. As this unexpected finding stands in contrast with previous results on the vitellogenin/JH interaction at a later age, when bees normally become foragers, we propose a three-step sequence in the constellation of physiological parameters underlying behavioral development. (AU)

• FAPESP's process: 05/03926-5 - Functional genomics of Apis mellifera: search for new genes and functional networks in the context of development, different castes and reproduction
• Grantee: Zilá Luz Paulino Simões
• Support Opportunities: Research Projects - Thematic Grants