Noah Whiteman, Professor

Closed (1) Horizontal transfer of toxin-encoding genes in drosophilid flies

Applications for fall 2021 are now closed for this project.

tbd

Day-to-day supervisor for this project: Kirsten Verster, Ph.D. candidate

Weekly Hours: 3-5 hrs

Related website: http://www.noahwhiteman.org/

Closed (2) Olfactory evolution in herbivorous insects

Closed. This professor is continuing with Spring 2021 apprentices on this project; no new apprentices needed for Fall 2021.

During the evolutionary transition from one feeding guild to another, such as microbe- to plant-feeding, it is hypothesized that behavioral adaptations are among the first to evolve. In insects, changes to the chemosensory systems that determine host preference are necessary, not only for finding an appropriate host, but in deciding at a fine spatial scale within an individual host where to feed and lay eggs. Understanding the functional genetic changes that underlie these complex behavioral shifts is a long-term goal in evolutionary biology. Scaptomyza flava, a small leaf-mining fly lends itself to be an ideal study system because (1) they evolved herbivory within the last 20 million years (relatively recent compared to other well-studied herbivores), (2) they can be collected on the UC Berkeley campus and are easily grown in culture on the model plant Arabidopsis thaliana, and (3) we can leverage the genetic tools of the model organism Drosophila melanogaster, its close relative. This project aims to characterize the changes in chemosensory, especially olfactory receptors that have enabled the evolution of herbivory.

This project will include:
1. Maintaining fly colonies
2. Growing host plants
3. Involvement in preparation and running behavioral assays

There is also the possibility of learning basic genetic molecular skills, such as DNA extractions, PCR, gel electrophoresis, and sequencing.

Day-to-day supervisor for this project: Teruyuki Matsunaga, Post-Doc

Qualifications: We are looking for a curious, highly motivated, and detail oriented student, who can operate independently but seek guidance when necessary.

Weekly Hours: 3-5 hrs

Related website: http://www.noahwhiteman.org

Closed (3) Horizontal transfer of toxin-encoding genes in drosophilid flies

Applications for fall 2021 are now closed for this project.

While much of genetic inheritance occurs via vertical transmission (i.e., from parents to offspring), the exchange of genes between species, or horizontal transmission, plays an important role in evolution. This process, called horizontal gene transfer (or HGT), is poorly understood in animals.

This project focuses on HGT of a toxin called cytolethal distending toxin B (cdtB) from microbial species to drosophilid fruit flies that occurred several million years ago. The persistence of cdtB in the drosophilid genome implies there is a functional, potentially adaptive role for this gene. Interestingly, bacterial copies of CdtB normally induce cell cycle arrest and cell death in animals. How Drosophila use CdtB, and how they do not harm themselves in the process, is unclear. We hypothesize Drosophila cdtB plays a protective role against parasitoid wasps and other predators. This project aims to explore how Drosophila use this gene as a defense mechanism without harming themselves.

This project will include:
1) Techniques in molecular genetics (i.e. DNA extraction, PCR, electrophoresis, sequencing)
2) Drosophila genetics and husbandry
3) Training in scientific methodologies, such as reading primary scientific literature and experimental design

Day-to-day supervisor for this project: Rebecca Tarnopol, Ph.D. candidate

Qualifications: No prior research experience required. Students should be curious, motivated, and excited to learn, especially from mistakes. Students in their first or second year of study, or with interests in genetics and evolution, are especially encouraged to apply.

Weekly Hours: 6-8 hrs

Related website: http://www.noahwhiteman.org

Closed (4) Evolutionary genomics of steroid biosynthesis and resistance in a toxic lily-herbivore system

Applications for fall 2021 are now closed for this project.

Lilies in the family Melanthiaceae produce steroidal alkaloids that are used as chemical defenses against herbivores. Some of these toxins are well known for their teratogenic and neurotoxic properties in animals. We still know little about the evolution of gene networks that produce these toxic compounds or the genetic basis of resistance in the herbivores (sawflies, moths, and flies) and pollinators (solitary bees) that specialize on them. By producing genomic data from wild-collected plants and insects, we aim to (1) understand how shared and unique genetic factors drive the diversification of plant chemical defenses and (2) dissect the genetic, developmental, and neural basis of resistance in the guild of insect that specialize on them.

TBD

Day-to-day supervisor for this project: Diler Haji, Ph.D. candidate

Weekly Hours: 6-8 hrs