The fan and rays of the C. elegans male tail constitute a compound sensory organ essential for mating. Within this organ, the individual sensilla, known as rays, have unique identities. We show that ray identities are patterned by a selector gene mechanism in a manner similar to other serially homologous axial structures. One selector gene that promotes the identities of a subset of the rays is...

The pheromone-binding proteins (PBPs), which exist at a high concentration in the sensillum lymph surrounding olfactory neurons, are proposed to be important in pheromone detection and discrimination in insects. Here, we present a systematic study of PBP-ligand interaction kinetics. We find that PBP2, from the gypsy moth, Lymantria dispar, associates and dissociates slowly with its biofunctiona...

Spiders have highly developed mechanosensory systems, some of which provide access to forms of stimulation alien to our own sensations. Studies of hair-shaped air movement detectors (trichobothria) and tactile sensors have uncovered an outstanding refinement of the processes of stimulus uptake and stimulus transformation, which reflect details of both stimulus physics and behavioral significanc...

In vertebrates, individual olfactory neurons are thought to express a single odorant receptor (Or) gene, but it is not clear that all odor-evoked activity in each neuron is exclusively dependent on an individual odorant receptor. In Drosophila, little is known about what receptors impart odor sensitivity to particular olfactory neurons. Here, we demonstrate the use of gene targeting to produce ...

Dipteran insects show a wide range of species-specific mating positions. Interspecific transitions from one position to another may reflect sexual or natural selection, or be pleiotropic consequences of other genetic changes. Like many cyclorrhaphan flies, Drosophila species mate with the male on the back of the female, positioned centrally. Mechanosensory sensilla on the male genitalia of thre...

The most challenging tasks for phytophagous insects are the location and selection of mates, food sources, and oviposition sites, all crucial for survival and reproduction. To perform these tasks insects rely largely on their sense of smell (olfaction). I address how the insect olfactory system discriminates between components of complex odor mixtures, modulating behavior and fitness. I have st...

Male moth pheromone-detecting receptor neurons are known to be highly specific and very sensitive. We investigated physiological and behavioral responses to female sex pheromone components in male Ostrinia furnacalis moths (Lepidoptera: Crambidae). Using recordings from a cut-sensillum technique, trichoid sensilla could be grouped into four physiological types (1-4), according to the response o...