Insects and Their Taste Receptors

Feb 21, 2013

Insects and Their Taste Receptors

Feb 21, 2013

If you want to know about the molecular neurobiology of feeding behavior in insects, then the University of California, Davis campus  is the place to be on Wednesday, Feb. 27.

Molecular neurobiologist Anupama Dahanukar, assistant professor at UC Riverside, will speak on "Taste Receptors and Feeding Preferences in Insects" at the UC Davis Department of Entomology seminar from 12:10 to 1 p.m. in Room 1022 of the Life Sciences Addition, corner of Hutchison and Kleiber Hall drives.

UC Davis assistant professor Joanna Chiu, who studies the molecular genetics of animal behavior, will host the seminar, which is scheduled to be recorded for later viewing on UCTV.

The seminar will focus on the common fruit fly, Drosophila melanogaster, exciting research under way in the Dahanukar lab.

"We are interested in the molecular neurobiology of feeding behavior," Dahanukar says. "Insects use highly diverse groups of gustatory receptors (Grs) to taste the chemical world and determine the palatability of potential food sources. In Drosophila melanogaster, the 68 receptors of this family are expressed in complex combinatorial patterns in taste neurons. In previous studies we and others identified a highly conserved clade of eight Gr genes that encode sugar receptors. Although some of these have been linked to detection of sweet compounds by genetic analysis, their precise functions are still poorly understood. Little is also known about how stimuli that are typically not rich in sugars trigger highly attractive gustatory responses in Drosophila."

"Using genetic and evolutionary analysis, we recently found that Gr64e, a receptor in this clade, plays an essential role in feeding preference for beer and other yeast fermentation products. We identified that Gr64e is necessary for neuronal and behavioral responses to an abundant component of yeast and fermentation products, glycerol. Moreover, Drosophila species that carry a polymorphism disrupting Gr64e function have reduced behavioral preference for beer, suggesting that Gr64e may contribute to specific evolutionary variations in appetitive selectivity. Ectopic expression of the Gr64e receptor in an olfactory neuron is sufficient to confer glycerol sensitivity. We have extended this ectopic expression system to identify that each sweet Gr protein serves as a determinant for recognition of unique but overlapping subsets of sweet tastants."

"We have also obtained functional expression of a taste receptor from the mosquito Anopheles gambiae in Drosophila. We are now poised to further investigate taste detection and Gr function in Drosophila and other insects."

A noted scientist, Dahanukar received a National Science Foundation Career Award in 2012; the  Whitehall Foundation Award in 2011; and the 2000 Ruth L. Kirschstein National Research Service Award. She was awarded a Government of India National Merit Scholarship in 1990.

Dahanukar holds a bachelor of science degree in life sciences from Bombay University, India;  a master's degree in environmental management from Duke University, Durham, N.C.; and a doctorate in genetics in 1999 from Duke University,  where she studied patterning along the anterior-posterior axis in Drosophila embryos. In 1999, she joined the laboratory of John Carlson at Yale University to pursue post-doctoral training in the molecular neurobiology of insect chemosensory systems. Dahanukar joined the faculty of the UC Riverside Department of Entomology in 2009.