Behavioral mechanisms underlying host specialization in specialist herbivorous flies.
Carolina Reisenman, Associate Researcher
Molecular and Cell Biology
Closed. This professor is continuing with Fall 2023 apprentices on this project; no new apprentices needed for Spring 2024.
Herbivory is a major evolutionary achievement in insects, with nearly half of all existing species feeding on living plants. While many herbivorous insects feed in many plant species, most herbivorous are specialists, with larvae feeding and adults ovipositing on a small number of closely related plant species. Transitions from a generalist lifestyle to specialization are common; in many cases morphological and physiological adaptations accompany host plant specialization, including detoxification mechanisms against plant defenses and sensory specializations for the detection of host-derived chemical (olfactory and taste) cues. In particular, the importance of the chemosensory system in host plant choice, along with the fact that specialists outnumber generalists, suggests that the evolution of insect– plant interactions is based on changes within the insect nervous system. Of particular interest among specialist herbivorous insects is the fly Scaptomiza flava, a species which is nested within Drosophila and is specialized in mustard plants such as broccoli, cabbage, radishes, arugula, etc. While this fly feeds on and needs plant tissue to complete its developmental cycle (i.e., it is a truly herbivorous insect), most of its close relatives are microbe-feeding and use decomposing material. Thus, this constitutes a great system to study the evolutionary transitions that allowed S. flava to use these plants, while at the same time help uncovering the general mechanisms that allowed insect shifts in dietary lifestyle.
The behaviors of S. flava and its close relatives, and their relevance for niche exploitation, begun to be uncovered only recently. Students will join current projects in the laboratory of Dr. Noah Whiteman involving chemosensory adaptations in diverse behaviors such feeding, oviposition, mate-choice, water-sensing, and adaptations of the visual system to host detection.
The students will learn to rear flies and their host plants, fly husbandry, laboratory methods, chemical ecology methods, help conducting ongoing behavioral tests of olfactory behavior, develop new methods for quantification of various behaviors, and collect and analyze data. Due to the comparative nature of this work, students will work with different fruit fly species in addition to S. flava.
Research for this project will be conducted in the laboratories of Drs. Noah Whiteman (Integrative Biology) and Kristin Scott (Molecular and Cell Biology).
Role: This project uses behavioral methods to study chemosensory adaptations to herbivory across closely related species of drosophilid flies. The student/s will learn how to rear and sort flies, learn fly genetics, fly husbandry, laboratory methods, conduct behavioral experiments, rear plants, collect and analyze data, and chemical ecology methods as necessary. They will also use tools readily available to investigate the role of specific chemosensory proteins in this process. The experiments will be conducted in the laboratory of Dr. Kristin Scott, under the supervision and direction of Dr. Carolina Reisenman.
Qualifications: General biology is required, general chemistry highly desirable, ecology/evolution preferable.
We are looking for one or more students who are curious, detail-oriented, punctual, and can collect/record data in an organized fashion, and is interested in reading relevant literature. The student will gain hands on experience being a scientist in a lab. Commitment and a positive attitude are a must!
The student should be available 8-10 hours during weekdays, and 2-3 hours (or more if case of scheduling conflicts during weekdays) during weekends. Please refrain from applying if you can't commit to at least 2-3 hours of work during weekends.
Hours: 9-11 hrs
Related website: http://www.noahwhiteman.org/
Related website: http://mcb.berkeley.edu/labs/scott/reisenman/