|Chen, Yanping - Judy|
Submitted to: Insect Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/22/2006
Publication Date: 7/11/2006
Citation: Evans, J.D., Aronstein, K.A., Chen, Y., Hetru, C., Imler, J., Jiang, H., Zhou, C., Kanost, M., Thompson, G., Hultmark, D. 2006. Immune pathways and defence mechanisms in honey bees Apis mellifera. Insect Molecular Biology. 15:645-656. Interpretive Summary: Enhancement of natural defenses is one strategy for helping bees survive attacks by parasites and pathogens. One line of defense that can be enhanced through breeding is the honey bee immune system. Using the Honey Bee Genome Project as a data source, we identified dozens of genes involved with this response in bees. We place these genes into ‘pathways’ that span from the moment an infection is noticed to the actual production of proteins that attack this infection. We can now use these pathways, and their end products, as tools to find out how bees respond to infections and why some bees do so better than others. These tools will help assess bee weaknesses with respect to immunity, a first step toward breeding stronger bees. The results should benefit bee breeding and management against American foulbrood, chalkbrood, and viral diseases of bees.
Technical Abstract: Sociality is a double-edged sword with respect to disease. On one side, societies are prime targets for disease agents. Social groups provide great opportunities for the horizontal transfer of parasites and pathogens and a concentration of exploitable resources including food and shelter. Social groups also tend to possess family structures that can improve the returns for disease agents that exploit genetic weaknesses. On the other side, social groups have great potential to mitigate disease pressures, through grooming and other shared behaviors and the maintenance of a controlled, often aseptic, environment. Understanding disease and immunity in societies requires an assessment of both group-level and individual responses to pathogens. Here we focus on individual responses by presenting the first global analysis of immunity in a social insect, the honey bee Apis mellifera. We have identified orthologs for virtually all members of the canonical innate immune pathways, yet find that most immune-related gene families have a strikingly reduced diversity in the bee genome. In the end, we connect insights into individual immunity back to the group-enabled disease resistance mechanisms found in this species. We suggest that the implied reduction in immune-system flexibility in bees reflects either the strength of social barriers to disease or a tendency for bees to be attacked by a limited set of highly coevolved pathogens.