Name: Astrid Wittmann
Education: Diplomacy Thesis and Doctoral Thesis at the University of Bremen and the Alfred Wegener Institute for Polar and Marine Research; Postdoctoral research at Colorado State University financed through a Marie Curie Fellowship from the EU
Hometown: Würtzberg, Germany
Career goal: Complete postdoctoral research at Colorado State University.
Favorite Memory: Watching a juvenile dungeness crab molt. “There’s a shiny and new carapace in just a few minutes – what looks so easy is quite a critical and complex process,” Astrid describes.
Project: Integration of environmental signals in molt regulation of decapod crustaceans (Molting & Climate)
Astrid researches the regulation of molting, the cellular signalling pathways involved in the process and how the environment affects it. As part of her Marie Curie Fellowship from the European Union, she learns new techniques on the molecular and cellular level. This integrative project allows her studies to range from the molecular level of the dungeness crab to the entire animal. “To understand the whole thing is one of my goals, but it’s not so easy,” Astrid admits.
In summer 2013, Astrid worked at the UC Davis Bodega Marine Laboratory, where she exposed crabs to different temperatures to determine their tolerance range. Astrid looks at the gene expression of AMPK and mTOR components to see how mTOR works on a cellular level to regulate molting. Astrid takes samples to analyze proteins such as phospho-AMPK within the crab’s tissue. This protein kinase acts in the pathway that controls stress responses to the environment. The greater the amount found, the more stressed the crabs feel. She uses those levels to determine which temperatures crabs can’t tolerate. The amount of lipids and proteins in a crab’s body can also indicate a crab’s ability to tolerate different temperatures. Astrid analyzes tissue for levels of carbon (a proxy for lipids) and nitrogen (a proxy for proteins). Crabs that are doing well have lots of lipids in their bodies and protein in their muscles. If the levels of both are low, a crab may be experiencing a temperature it can’t tolerate.
She also looks at molting and gene expression of mTOR components throughout the molting cycle to see how mTOR works in the cellular pathway that regulates molting. The gene mTOR regulates cell growth and protein synthesis. On a larger scale, she studies crab growth by weighing them periodically and measuring the width increase in their carapaces, or upper shells, each time they molt.