Monday, December 10, 2007
D0184

Gene expression related to the insulin signaling pathway and foraging behavior of honey bees (Apis mellifera)

Ying Wang, ying.wang.6@asu.edu, Gro Amdam, gro.amdam@asu.edu, M. Kim Fondrk, Michael.Fondrk@asu.edu, and Robert Page, robert.page@asu.edu. Arizona State University, School of Life Sciences, ISTB-1, Box 4501, Tempe, AZ

Recent studies of the honey bee (Apis mellifera) have indicated that remnant components of the ancestral gonotrophic cycle, particularly the endocrine system, may modulate foraging behavior. An upstream regulator of these endocrine cascades is the insulin/IGF-like signaling (IIS) pathway. To determine if the IIS is directly involved in foraging preference in honey bee workers, we examined expression patterns of 12 genes related to the IIS pathway using Real-time PCR. Samples were drawn from strains selectively bred for either a high or low preference for pollen hoarding. Significant differences between strains were found in a subset of these genes. Expression levels of Chico and PDK1, which play important roles in IIS, progressively increased in both strains from the larval stage until the onset of foraging in adults (Anova P<0.05). Among foragers, the high strain expressed significantly more of both genes than the low strain (P<0.05). The Midway gene, involved in lipid metabolism and oocyte development, has the highest expression in newly emerge bees (Anova P<0.05). During larval and forager stages, Midway is significantly higher in the high pollen-hoarding strain (P<0.05). Midway is particularly interesting because it encodes diacylglycerol acyltransferase, which has been shown to alter sensitivity to IIS. These data support a model in which the IIS pathway is involved in foraging behavior.


Species 1: Hymenoptera Apidae Apis mellifera (honey bee)