NSF Postdoctoral Fellowship in Biology for FY 2011

这一行动资助了NSF 2011财年生物学博士后研究奖学金，生物学与数学和物理科学的交叉点。该奖学金支持在宿主实验室为这位处于生物学和物理学交叉点的研究员制定研究和培训计划。玛丽亚·卡门内茨卡的这项研究和培训计划的标题是《解开DNA：测量单个DNA分子的机械硬度以了解组蛋白对基因转录的控制》。这项研究的主办机构是耶鲁大学，赞助科学家林恩·里根博士和西蒙·莫克里博士。组蛋白将DNA包装成染色质。这项研究探索了组蛋白如何控制DNA的解离，为导致蛋白质合成的步骤打开DNA。组蛋白的变化被认为会影响染色质的柔韧性，从而影响DNA转录的可及性。单分子纳米操纵和物理力谱技术正被用来定量评估组蛋白修饰对DNA的影响。目前正在准备完全由野生型或修饰组蛋白组成的染色质，以用于使用光钳和基于AFM的力光谱技术来拉伸单个染色质系链并测量其机械和结构特性的研究。这些实验能够明确地比较具有不同组蛋白组成的单个DNA分子的柔韧性，从而揭示组蛋白在控制基因表达中的作用。培训目标包括学习分子生物学技术和获得相关的生化技能，以制备染色质纤维的均一制剂。更广泛的影响包括对生物学学生进行教育，让他们学习单分子纳米操纵技术，以及在主办机构普遍促进生物科学中的物理方法的传播。此外，外展还包括开发和教授一个以物理为基础的模块，以补充突破新天堂的生物课程，这是一个针对贫困中学生的暑期项目。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2011, Intersections of Biology and Mathematical and Physical Sciences. The fellowship supports a research and training plan in a host laboratory for the Fellow at the intersection of biology with physics. The title of the research and training plan for this fellowship to Maria Kamenetska is "Unwinding DNA: measuring mechanical stiffness of a single DNA molecule to understand histone control over gene transcription." The host institution for this fellowship is Yale University with sponsoring scientists Drs. Lynne Regan and Simon Mochrie.Histone proteins package DNA into chromatin. This research explores how histones control the unwinding of DNA to open it for the steps that lead to protein synthesis. Changes in histones are believed to affect the pliability of chromatin and thus the accessibility of DNA for transcription. Single molecule nano-manipulation and force-spectroscopy techniques from physics are being used to quantitatively assess the affect of histone modification on DNA. Chromatin re-constituted with exclusively wild-type or modified histones is being prepared for studies that use optical tweezers and AFM-based force-spectroscopy techniques to stretch single chromatin tethers and measure their mechanical and structural properties. These experiments enable an unambiguous comparison of pliability of individual DNA molecules with different histone compositions and thus reveal the role of histones in controlling gene expression.Training objectives include learning molecular biological techniques and acquiring relevant biochemical skills to prepare homogenous preparations of chromatin fibers. Broader impacts include educational outreach to biology students to learn single molecule nano-manipulation techniques and generally promoting the dissemination of physical approaches in biological science at the host institution. Also, outreach includes developing and teaching a physics-based module to supplement the biology curriculum for Breakthrough New Heaven, a summer program for disadvantaged middle-school students.