1 / 14

My Summer Undergraduate Research Experience

My Summer Undergraduate Research Experience. Kinetics of Thyroid Hormone Receptor α Nuclear Import. Xenopus laevis. Background. Thyroid gland secretes two similar hormones (T 3 and T 4 ) that play a pivotal role in development and maturation.

moya
Download Presentation

My Summer Undergraduate Research Experience

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. My Summer Undergraduate Research Experience

  2. Kinetics of Thyroid Hormone Receptorα Nuclear Import Xenopus laevis

  3. Background • Thyroid gland secretes two similar hormones (T3 and T4) that play a pivotal role in development and maturation. • The thyroid hormone receptor (TR) is a nuclear protein which, in response to T3, promotes or represses gene transcription. • Therefore, the mechanism regulating the subcellular distribution of TR is an extremely important topic. Thyroid Gland

  4. Nuclear Pore Complex • Molecules that are ~50kDa can passively diffuse through the NPC • Energy-independent process • Does not require NPC interaction • Temperature-independent • Molecules can be actively transported through the NPC • Energy-dependent process • Requires interaction with the NPC or import receptor • Temperature-dependent Cytoplasm Central Transporter Nucleus http://www.scripps.edu/~stoffler/proj/NPC/npc.html

  5. QUESTION • Why, if TR can enter the nucleus by an energy-independent process it has also evolved to follow a signal-mediated process. • HYPOTHESIS: • Signal-mediated import will occur more rapidly than passive diffusion.

  6. Xenopus laevis • Surgically remove Xenopus oocytes.

  7. Manually microinject radioactively labeled TR into the cytoplasm. Vegetal Pole Inject 35S-TR Animal Pole (where nucleus resides)

  8. Block signal mediated transport of TR by keeping oocytes at 4 °C. • Compare the nuclear localization rate of TR with its rate in oocytes incubated at 20 °C. 20 °C 4°C

  9. At various time points, manually dissect nuclei from “cytoplasms” (enucleated oocytes). • Separate proteins using SDS-polyacrylamide gel electrophoresis. • Detect radioactive TR by exposing the dried gel to X-ray film. Cytoplasm Nucleus

  10. Autoradiogram 4° Nuc Experiment incubated for 2.5 hours. 20° Cyto 20° Nuc 4° Cyto Oocytes incubated at 20° C have a noticeably greater amount of TR in the nucleus as compared to oocytes at 4° C. 35S-TRα

  11. General trend of increased nuclear localization with time. • Oocytes at 20°C consistently had a greater %Nuclear TR than 4°C.

  12. Benefits of Research • Patience, Determination and Perseverance • Surrounded daily by people with the same interests • Perfect my public speaking skills. • Drastically different experience than classes • Analyzing novel data vs. regurgitation of facts. • Hands on Experience- learn by doing. • Get to know Professors in the Biology Department • Dr Allison and I are now best friends. • Lab meeting twice a week with Dr. Shakes in the summer. • Scientific ethics seminars with Dr. Heideman.

  13. My Future Plans • Next year I will attend medical school. • Applied to schools with excellent research programs. • Hope to combine my affinity for research and medicine. • Continue molecular biology research pertaining to human disorders. • Get involved with clinical research.

  14. Acknowledgements • Dr Allison for her expert advice, time and incredible patience. • Funding from NSF and NIH for L.A.A. • Supported by HHMI Summer Research Fellowship, HHMI Minor Research Grant, Minor Research Grant from the College of William and Mary.

More Related