Dr. Cozy is a microbiologist with a research interest in how microorganisms develop specialized cell types. She uses a cyanobacterium called Anabaena as a model of this process. When times are good, Anabaena grows as filaments of hundreds of vegetative (dividing) cells long. However, when Anabaena is starved for fixed (bioactive) nitrogen every 10th cell of the filament makes the developmental decision to permanently differentiate (change) into a specialize cell called a heterocyst. Heterocysts are capable of pulling atmospheric nitrogen from the air, fixing it into a usable form, and then sharing it with the rest of the cells in the filament. It is, however, a one-way trip for a vegetative cell to become a heterocyst. The heterocyst ceases to divide, loses its ability to do photosynthesis and becomes dependent on the rest of the cells of the filament for survival. It's an act of microbial altruism.
Several interesting developmental questions arise from this situation:
How does Anabaena ensure that heterocysts are evenly spaced along a filament?
How does an Anabaena cell decide to terminally commit to a heterocyst fate?
How does Anabaena permanently turn off cell division in these specialized cells?
Dr. Cozy’s research uses classical and molecular genetics to find genes that regulate these processes and uses molecular and microscopic analyses to examine when and where these genes are expressed during development. She encourages students to engage in research in her lab and then communicate their findings.
Dr. Cozy teaches