Submitted by Dr. Lisa Petrella
The Petrella Lab is interested in how worms develop in the face of changing temperature. We need to be able to visualize how chromosomes and other cellular structures form or misform when challenged with hot temperatures. The worms we work with are only ~ 1mm long, so from nose to tail only about the 10x length as the width of a human hair. This makes it very challenging to clearly image small things like chromosomes inside of cells. The main problem with small imaging is out-of-focus light. We have recently obtained a new Leica microscope that allows us to quickly create clear images, giving us the ability to view the three-dimensional structures within cells. Two important parts of the microscope allow us to do this. 1) A platform that the worm sample goes on that has a very precise motor to allow us to move the sample up and down (which means in and out of the light we are shining on it) with very small steps. 2) A powerful computer program that uses algorithms called deconvolution to mathematically remove any out-of-focus light. The picture above is an image of a worm oocyte before and after deconvolution taken and processed by Brian Mikeworth, our lab manager. The image on the left is blurry and it is hard to see the 6 chromosomes clearly, however, after deconvolution we can clearly see the shape and structure of the chromosomes. We are now using this microscope to investigate many questions about how cells change in the worms when they are exposed to high temperatures.
Dr. Kathy Karrer and Dr. James Courtright will both retire at the end of this spring semester. After completing a Ph.D. at Johns Hopkins, and a postdoc at the University of Texas, Austin, Dr. Courtright started his research and teaching career in the Department of Biology at Marquette University in 1970. He feels blessed to have had the good fortune of having some truly remarkable students pass through his lab over the years. He feels one of his most rewarding contributions has come from imparting to them the excitement of the experiment and the joy in making new discoveries. Read more about Dr. Courtright's career here. Dr. Karrer came to Marquette in 1989 from Brandeis University as a Clare Boothe Luce Professor. Read more about her career in this issue's Current Faculty Feature. Both are looking forward to their retirement, and will be sorely missed here at Marquette.
Do you remember what you did as a freshman at Marquette?
For a group of bright and talented biology students, they will especially remember doing scientific research as freshman. This year as part of a first year experience in Biology, thirteen students had the opportunity to take a unique lab class called Foundations in
Biological Inquiry. Students spent the first half of the semester applying the scientific method to short inquiry projects. Afterwards, students embarked on an eight-week faculty mentored undergraduate research project that they designed and conducted themselves. “It’s amazing what students can do when they are given the opportunity to think,” said Dr. Anita Manogaran, faculty member in Biological Sciences and instructor for the course. “They developed their own hypothesis, figured out what controls they needed, what conditions needed to be tested, and they generated data!” The student work culminated in a poster session in the Biological Sciences undergraduate symposium, where students presented their work to other undergraduate students, graduate students and faculty.
We hope that you’ve hit the “Like” button on our Facebook page to follow the activity of the department! It’s a great way to keep in touch, and we’d love to know more about what you’d like to see. Are you interested in keeping up with faculty research, what students are doing, or career progress of other alums? Let us know what you think!