During a rotation in the Karlstrom lab, Mary Catherine Catanese studied the role that Hedgehog (Hh) signaling plays in the regulation of growth of the post-embryonic zebrafish pituitary gland. The pituitary gland comprises multiple hormonal cell types that dynamically regulate numerous physiological processes. Hh signaling plays a critical role in the induction and patterning of the pituitary during embryonic development. Surprisingly, the mechanisms that regulate post-embryonic growth and adult endocrine cell numbers remain largely unknown. Our preliminary work has revealed that a subset of pituitary cells continues to respond to Hh signaling in the larval and adult pituitary, and that these cells are proliferative, suggesting Hh signaling may regulate cell numbers throughout life. Consistent with this idea, mis-regulation of Hh signaling has been associated with human pituitary tumors. By studying the cellular response to manipulation of Hh signaling we can begin to unravel the mechanisms behind Hh regulation of pituitary growth, cell proliferation, and pituitary tumor formation. These studies may also help to better elucidate the role of Hh signaling in the regulation of cell cycle progression in order to better understand how mis-regulation of Hh signaling leads to pituitary adenomas and other endocrine related cancers.
Mary earned a B.A in English, with a minor in Psychology and a Film Studies Certificate from the University of Massachusetts at Amherst. She is currently finishing her Ph.D. in the School of Public Health at U Mass.
Tg(GBS-ptch2:nls) SL 15mm
Title: Transverse view of Hh responsive transgenic adult zebrafish pituitary resting beneath ventricular zone of hypothalamus.
Hh responsive cells labeled with GFP and proliferative cells labeled with anti-BrdU antibodies in red
Tg(GBS-ptch2:nls) SL 8mm
Title: A view into the active Hh response and proliferative zones of the larval zebrafish brain.
GFP labels nuclei of Hh responsive cells, BrdU in red reveals proliferative cells
same as above but with dapi