Physiological and behavioral changes in honey bees (Apis mellifera) induced by Nosema ceranae infection

PLoS One. 2013;8(3):e58165. doi: 10.1371/journal.pone.0058165. Epub 2013 Mar 6.

Abstract

Persistent exposure to mite pests, poor nutrition, pesticides, and pathogens threaten honey bee survival. In healthy colonies, the interaction of the yolk precursor protein, vitellogenin (Vg), and endocrine factor, juvenile hormone (JH), functions as a pacemaker driving the sequence of behaviors that workers perform throughout their lives. Young bees perform nursing duties within the hive and have high Vg and low JH; as older bees transition to foraging, this trend reverses. Pathogens and parasites can alter this regulatory network. For example, infection with the microsporidian, Nosema apis, has been shown to advance behavioral maturation in workers. We investigated the effects of infection with a recent honey bee pathogen on physiological factors underlying the division of labor in workers. Bees infected with N. ceranae were nearly twice as likely to engage in precocious foraging and lived 9 days less, on average, compared to controls. We also show that Vg transcript was low, while JH titer spiked, in infected nurse-aged bees in cages. This pattern of expression is atypical and the reverse of what would be expected for healthy, non-infected bees. Disruption of the basic underpinnings of temporal polyethism due to infection may be a contributing factor to recent high colony mortality, as workers may lose flexibility in their response to colony demands.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Analysis of Variance
  • Animals
  • Appetitive Behavior / physiology
  • Bees / microbiology*
  • Bees / physiology*
  • Juvenile Hormones / metabolism*
  • Minnesota
  • Nesting Behavior / physiology*
  • Nosema*
  • Observation
  • Radioimmunoassay
  • Real-Time Polymerase Chain Reaction
  • Spores, Fungal / physiology
  • Vitellogenins / metabolism*

Substances

  • Juvenile Hormones
  • Vitellogenins

Grant support

This research was supported by a United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA)-Coordinated Agricultural Project (CAP) grant awarded to MS and ZH and research grants from North Central Region Sustainable Agriculture Research and Education (NCR-SARE) and the Eastern Apicultural Society awarded to MG. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.