Dartmouth Medical School
Department of Genetics
7400 Remsen
Hanover, NH 03755
Genetics.Department@Dartmouth.edu
603/650-1907
Male Drosophila respond to female pheromones with an elaborate
courtship display that involves vibrating one wing to generate a specific song.
Our lab is interested in defining the cellular and molecular events that
underlie this behavior.
Contact: Claudio Pikielny
We study the response of Drosophila to pheromones and take advantage of the many molecular genetic tools available in this model system. Currently, our lab is focusing on two very different types of genes that play a role in this response.
CheBs are novel genes that play an important role in modulating
gustatory response to pheromones (2,4).
We have discovered a family of twelve Drosophila genes, the CheBs, several of
which are only expressed in a few taste hairs of males, suggesting that they
may play a role in gustatory response to female pheromones. Expression of
CheB42a in particular, is restricted to the sheath cells that surround a set of
gustatory neurons known to be involved in response to pheromones. Indeed, we
have now shown that males with mutations in the CheB42a gene have a very
specific defect in their response to hydrocarbon pheromones emitted by females:
they attempt to copulate earlier and more frequently than normal males.
Circumstantial evidence suggests that CheB42a and other CheBs may act by
binding to pheromone molecules and modulating their interactions with
transmembrane receptors. We are currently testing this hypothesis.
A Drosophila DEG/ENaC Sodium Channel subunit is specifically
required for male response to female pheromones (3).
We have recently found that ppk25, a gene coding for a sodium channel subunit
of the DEG/ENaC family is preferentially expressed in appendages involved in
olfaction and taste, and is specifically required for males to detect female
pheromones. While other DEG/ENaC channels are involved in a variety of
biological processes, from mechanosensation to control of blood pressure and
even stroke, this is the first instance where a channel in this family has been
implicated in a G-protein coupled chemosensory transduction pathway. We are
currently examining the mechanistic basis for ppk25's specific function in
pheromone response.
1. Park, S.-K., Shanbag, S., Wang, Q., Yu, P., Hasan, G., Steinbrecht, A., and Pikielny, C.W. (2002). Inactivation of olfactory sensilla of a single morphological type differentially affects the response of Drosophila to odors. J Neurobiology 51:248-60. Link to article.
2. Xu, A., Park, S.-K., D'Mello, D., Kim, E., Wang, Q. and Pikielny, C.W. (2002). Novel genes expressed in subsets of chemosensory sensilla on the front legs of male Drosophila. Cell Tissue Res 307:381-92. Link to article.
3. Lin, H. Mann, K.J., Starostina, E., Kinser, R.D. and Pikielny, C.W. (2005) A Drosophila DEG/ENaC channel subunit is required for male response to female pheromones. Proc Natl Acad Sci USA. 2005 Sep6;102(36):12831-6. Link to article.
4. Park, S.K., Mann, K.J., Lin H., Starostina, E., Kolski-Andreaco, A. and Pikielny, C.W. (2006). A Drosophila protein specific to pheromone-sensing gustatory hairs delays males' copulation attempts. Curr Biol 16:1154-59. Link to article.
5. Starostina, E., Xu, A., Lin, H., Pikielny, C.W. (2008) A Drosophila protein family implicated in pheromone perception is related to Tay-Sachs GM2-activator protein. Journal of Biological Chemistry (in Press, published online October 24, 2008). Link to article.
