This strong relationship surfaced in a complex molecular study of 6,878 different genes replicated with 72 cDNA microarrays that captured the essence of brain gene activity within the natural world of the honey bee (Apis mellifera). Even though most of the differences in gene expression were small, the changes were observable in 40 percent of the genes studied, the scientists report in the Oct. 10 issue of the journal Science.
"We have discovered a clear molecular signature in the bee brain that is robustly associated with behavior," said principal researcher Gene E. Robinson, a professor of entomology and director of the Neuroscience Program at Illinois. "This provides a striking picture of the genome as a dynamic entity, more actively involved in modulating behavior in the adult brain than we previously thought."
Microarrays let researchers get a broad view of gene activity by generating simultaneous measurements of messenger RNA, which reflect levels of protein activity. The mRNA binds to specific sites on the array, allowing for the measurement of expression from thousands of genes.
Robinson, who also holds the G. William Arends Professorship in Integrative Biology at Illinois, and colleagues generated mRNA profiles from 60 different bees who were working either as nurses (taking care of the brood within the hive) or foragers (gathering food outside). A computer program was able to use the profiles to determine correctly, for 57 of 60 the bees, which individual belonged to what group.
Behavioral differences between nurses and foragers are part of an age-related, socially regulated division of bee labor. Nurses perform care-giving duties for their first two to three weeks
Contact: Jim Barlow
University of Illinois at Urbana-Champaign