We use planarian flatworms to understand the mechanisms of regeneration. Unlike more established model organisms, planarians rapidly regenerate all of their organs by activating an abundant population of pluripotent stem cells. Just as in mammals, injury stimulates unique cellular behaviors that lead to the restoration of functional organs. However, many questions remain as to how pluripotent stem cells are triggered to proliferate, how they “know” which tissues need to be replaced, and how they coordinate their activity to produce functional tissues. Our goal is to understand how this process works.
Project 1: Organ regeneration
Our focus is on regeneration of one organ, the pharynx. The pharynx is the mouth of planarians. In the video below, the pharynx is the large, white tube that sucks up food into the animal’s body.
Project 1: Organ regeneration
Our focus is on regeneration of one organ, the pharynx. The pharynx is the mouth of planarians. In the video below, the pharynx is the large, white tube that sucks up food into the animal’s body.
We discovered a method to selectively remove this organ by soaking animals in sodium azide. We call this amputation strategy "chemical amputation" to contrast it with the typical "surgical amputation" which begins with a razor blade.
After removing the pharynx, the stem cells in the rest of the body are activated to regenerate a new pharynx. Our goal is to understand the molecular and cellular mechanisms responsible for pharynx regeneration. We use functional genetics (RNA interference) and transcriptomics to identify genes involved in pharynx regeneration.
Project 2: Stem cell responses to radiation
Like any dividing cell, planarian stem cells are sensitive to DNA damage, most commonly delivered by radiation. Exposing planarians to radiation introduces double-strand breaks, preventing cell cycle progression and leading to rampant cell death via apoptosis. Because radiation potently induces loss of stem cells, much like it does in humans to mitigate tumorigenesis, we use radiation to study the cell biological effects of DNA damage. We discovered that mechanical injuries of any kind will delay this inevitable death, but only locally, in the vicinity of the wound. We are very interested in the molecular and cellular mechanisms linking injury to apoptosis.
To answer these questions, we employ a multi-pronged approach using transcriptional profiling, RNA interference screens, immunohistochemistry and in situ hybridizations.
After removing the pharynx, the stem cells in the rest of the body are activated to regenerate a new pharynx. Our goal is to understand the molecular and cellular mechanisms responsible for pharynx regeneration. We use functional genetics (RNA interference) and transcriptomics to identify genes involved in pharynx regeneration.
Project 2: Stem cell responses to radiation
Like any dividing cell, planarian stem cells are sensitive to DNA damage, most commonly delivered by radiation. Exposing planarians to radiation introduces double-strand breaks, preventing cell cycle progression and leading to rampant cell death via apoptosis. Because radiation potently induces loss of stem cells, much like it does in humans to mitigate tumorigenesis, we use radiation to study the cell biological effects of DNA damage. We discovered that mechanical injuries of any kind will delay this inevitable death, but only locally, in the vicinity of the wound. We are very interested in the molecular and cellular mechanisms linking injury to apoptosis.
To answer these questions, we employ a multi-pronged approach using transcriptional profiling, RNA interference screens, immunohistochemistry and in situ hybridizations.
