My students and I use a molecular genetic approach to answer interesting biological questions about the genetic basis of behavior. That is, we look at the effect of the expression of certain genes on the behavior of an animal, including the animal’s ability to sense and respond appropriately to its environment. The animal we study is a small free-living roundworm, Caenorhabditis elegans. This small (1 mm) worm can be found eating bacteria in your compost pile. Despite its small size and seeming simplicity, this worm is capable of sensing chemicals in the air (smell) and in liquid (taste), it has a sense of touch (mechanosensation), and it can learn and remember things. Male C. elegans also have a complex mating behavior. We are interested in how these behaviors are manifested; specifically, we want to know which genes need to be used and which proteins need to interact in order to allow these behaviors to take place.
We have completed a study of the role of a putative potassium channel in male mating behavior. Students in my lab isolated interesting alleles of the gene sup-9, thought to encode a potassium channel. These mutant alleles visibly affect male worms, making them unable to mate because they do not move as elegantly as they should. This work sas funded by several grants from the NIH-AREA program.
In 2009, I spent six months working at the Karolinska Institute in Sweden, collaborating with Dr. Peter Swoboda. We are continuing to collaborate on a project to determine which genes are needed to maintain neuronal synapse function in adult worms. The Swobada lab already demonstrated that reductions in a particular neuronal protein, DAF-19, that encodes a transcription factor, reduces neuron-neuron communications (synaptic transmission) similar to what is seen in early hallmarks of diseases such as Alzheimer’s. We are using C. elegans as a model system to determine which genes are controlled by the DAF-19 transcription factor and that are needed to maintain synaptic functions. A genome-wide screen of the transcriptome of mutant and wild type worm populations has provided us with a list of 174 possible genes to study! Students who currently work in my lab learn techniques such as PCR, site-directed mutagenesis, molecular cloning, production of transgenic worms, bioinformatics, confocal microscopy, and basic genetics.
In a related project, we are working to determine whether the genes identified as perhaps being controlled by the DAF-19 transcription factor share a similar enhancer or promoter sequence (to which DAF-19 or its partners might bind). Chelsey Sand, pictured above, used a bioinformatics approach to compare the sequences upstream of the genes we are studying to find common sequences. We call the sequence she identified the SandBox!
The education and training of new scientists is the best job in the world. In my courses, I'm able to explain, synthesize, and place into a broader context the very latest discoveries in genetics and molecular biology (what fun!). The laboratory investigations for these courses continually evolve as new technologies and techniques are invented. Students thus learn the most up-to-date techniques as well as concepts and mechanisms of inheritance and gene expression. My goals for students include that they should learn to think critically, to have a healthy skepticism that includes searching out alternative explanations and hypotheses, that they can analyze and interpret data, and design experiments to test new hypotheses about how the natural world works. Students need to learn to think like scientists. Through the biology curriculum, students have many opportunities to design experiments that test their hypotheses, to learn patience and creativity as they execute their experiments, and to their analytic skills as they determine the significance of their data and prepare it for dissemination. Students practice their communication skills: clear and cogent writing as well as articulate speaking. These skills serve students well no matter what field they chose to enter after graduation from Lawrence.
Biology 130: Integrative Biology, Cells to Organisms
Biology 130 is the first course in our introductory biology sequence. This course has two main themes: That living things are dynamic systems with lots of movement and change within them, and that living things are based on molecular interactions that are not simply mechanical but that demonstrate emergent properties – properties of the whole that are not due to any one element of the system alone. The laboratory portion of the course includes a 5-week small group research project co-designed with a faculty mentor. This is a great opportunity for students to work in an area of biology they think they might want to pursue further or just to try something they’ve never done before.
Biology 260: Genetics
A course that covers both molecular and classical genetics, designed for sophomores and juniors. The ever-evolving laboratory component includes the use of PCR and restriction digests for human DNA fingerprinting, explorations of bioinformatics, mapping a mutant gene, connecting phenotype/genotype/DNA sequences in a 3-week project, and discussions of the ethics surrounding the use of genetic information (ranging from personal genomics to eugenics).
Biology 235: Evolutionary Biology
Biology 235 is a speaking-intensive course in which student focus on learning to effectively disseminate and discuss scientific information while learning current approaches to studying the processes of selection, mutation, and genetic drift. Two regular class periods and one discussion of primary literature per week provide a collegial environment in which students hone their oral skills. Interesting topics discussed in the course include: examples of speciation, sexual selection, production of new genes and alleles, the origin of eukaryotes, the magisteria of science and religion.
I also frequently teach Freshman Studies and the Biology Senior Experience Course.
Other Professional Activities
In addition to the fun of teaching and undertaking research, I have the good fortune to serve as a senior editor for a newly designed section of the journal Genetics, the flagship publication of the Genetic Society of America. In this capacity, I recruit authors and edit manuscripts that are called ‘primers.’ These primers take a hard-to-understand current research paper in the field of Genetics and make it accessible to undergraduate readers (and their instructors!).
I also serve as a frequent textbook reviewer, journal reviewer, and member of NSF grant review panels.