From Society to Genes with the Honey Bee
A combination of environmental, genetic, hormonal and neurobiological factors determine a bee's progression through a series of life stages
On September 9, 1997, an article in The New York Times announced the discovery of the "first gene for social behavior." Anthony Wynshaw-Boris, of the National Human Genome Research Institute, and his colleagues had discovered odd behavior in laboratory mice lacking a gene called disheveled-1. These mice interacted and huddled with others less than normal, and they failed to perform an important social duty, trimming the whiskers of fellow mice. Whether or not this is really the first gene discovered "for social behavior," no one should lean toward the notion that genes play an exclusive role in regulating behavior. Biologists long ago came to realize that behavior is influenced by genes, the environment and interactions between the two. To better understand this regulatory combination, scientists can turn to an organism, such as the honey bee, whose behavior can be studied in the field under natural conditions.
A discussion of "genes for behavior" might raise anxiety over the implications of attributing so much control to strings of nucleic acids, or DNA. In particular, some people fear that the concept of biological determinism—the notion that genes play a dominant, if not exclusive, role in regulating behavior—might creep in and diminish our appreciation for the role of the environment in shaping behavior. Nevertheless, genes never act alone. They must operate in an environment, where they code for proteins that participate in many systems in an organism. In fact, genes themselves depend on many of those proteins for replicating DNA and linking together amino acids, which are the fundamental units of proteins. Consequently, biologists need to take a broad approach in assessing the impact of any gene.
To properly appreciate the influence of genes on behavior, we need behavioral studies that demonstrate—at the molecular level—the influences of genes, the environment and their interactions. Social behavior is ideally suited for this challenge because it is especially sensitive to environmental influence. Moreover, these influences are in many cases mediated by specific social signals communicated from individual to individual, which can make them easier to study experimentally. Molecular-genetic studies of social behavior will show how an animal's phenotype, which includes social behavior, arises from both its genotype and environment. Making that connection, however, requires identifying genes that influence social behavior, revealing how those genes regulate the neural and endocrine mechanisms through the production of proteins, and, finally, exploring how specific manipulations of an animal's social environment affect gene expression.
My research group uses the Western honey bee, Apis mellifera, to understand how genes and the environment govern social behavior. As I shall show, we study the development of naturally occurring social behavior, from society to gene. Honey bees are particularly useful for studying social behavior because, like humans, they experience behavioral development. In other words, honey bees pass through different life stages as they age, and their genetically determined behavioral responses to environmental and social stimuli change in predictable ways. Often these responses increase in complexity and involve learning. We hope to explain the function and evolution of behavioral mechanisms that integrate the activity of individuals in a society, neural and neuroendocrine mechanisms that regulate behavior within the brain of an individual, and genes that influence behavior by encoding these mechanisms.
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