Christopher Smith

UM #30858384

Dr. Cunming Duan

  1. The research field is developmental biology focusing on the regulation of cell growth, proliferation, differentiation, migration, survival and death. good
  2. Duan hypothesized that binding proteins BP-2 and BP-5 regulated optical cell growth rather than IGF-I and IGF-II. So, these proteins do not regulate IGF-I or II…?
  3. This hypothesis was important to test because the mechanisms of the regulation of regulating cell growth are still not understood. These studies could test whethershow that binding proteins are critical for development.
  4. In situ hybridization of IGF-I and IGF-II mRNA expression was performed to identify the location of the insulin growth factors expression. Labeling of BrdU was done to identify BP-2 and BP-5 Are you sure? Didn’t BrdU test for cell division? How would BrdU identify the substances?. Several specific stains were used to stain the various cells of the eye to qualitatively measure growth.Does staining cells measure cell growth directly? Or does it identify different cell types, that could then be counted and compared with controls?
  5. Duan wanted to test whether binding proteins were critical to cell growth regulation. Therefore, during all tests he kept the concentrations of IGF-I and IGF-II constant. He then increased the concentrations of growth inhibiting BP-2 in the eye of a zebra fish to test whether less cell growth would occur. In a separate sample, he increased the concentrations of growth stimulating BP-5 to test whether increased amounts of cell growth would appear. good
  6. Duan could have found the increased BP-2 decreased cell growth while increased BP-5 increased cell growth. This result would have confirmedsupported the hypothesis that binding proteins regulate the growth or cells in addition to IGF. If BP-2 had increased cell growth and/or if BP-5 had inhibited growth, then binding proteins could have been interpreted as regulating cell growth, but how they were regulating growth would need to be reevaluated—although these growth inhibiting and promoting mechanisms could have been specific for the eye. Increasing the amounts of BP-2 and BP-5 could have led to no change in natural ocular growth. This result would suggest than the binding proteins were not essential in the binding of IGF to their receptors. OK, but note that hypotheses are to be tested, and can be refuted or supported, but by definition cannot be confirmed.
  7. NO PICTURE OR GRAPHIC AVAILABLE FROM THE REVIEW TO FURTHER THIS HYPOTHESIS.
  8. Is either BP-2 or BP-5 dominate over the other in the regulation of cell growth or differentiation?

Good, A-.

It is unusual for you, but your description of the methods used reveals some misconceptions of how those methods work and what they can and cannot show. Could you rewrite that question, for an A?