Chinese Academy of Sciences

3 ARTICLES PUBLISHED IN JoVE

Biology

Single-molecule Imaging of Gene Regulation In vivo Using Cotranslational Activation by Cleavage (CoTrAC)

Zach Hensel¹, Xiaona Fang^1,2,3, Jie Xiao¹

¹Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, ²Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , ³Department of Physics, Jilin University

We describe a fluorescence microscopy method, Co-Translational Activation by Cleavage (CoTrAC), to image the production of protein molecules in live cells with single-molecule precision without perturbing the protein's functionality. This method has been used to follow the stochastic expression dynamics of a transcription factor, the λ repressor CI ¹.

Biology

Collection, Isolation and Enrichment of Naturally Occurring Magnetotactic Bacteria from the Environment

Zachery Oestreicher¹, Steven K. Lower^1,2, Wei Lin³, Brian H. Lower²

¹School of Earth Sciences, The Ohio State University, ²School of Environment & Natural Resources, The Ohio State University, ³Institute of Geology and Geophysics, Chinese Academy of Sciences

We demonstrate a method to collect magnetotactic bacteria (MTB) that can be applied to natural waters. MTB can be isolated and enriched from sediment samples using a relatively simple setup that takes advantage of the bacteria's natural magnetism. Isolated MTB can then be examined in detail using both light and electron microscopy.

Developmental Biology

In Vitro Growth of Mouse Preantral Follicles Under Simulated Microgravity

Shen Zhang¹, Yonggen Wu¹, Yimin Weng², Zhihui Xu¹, Wenmin Chen³, Dahan Zheng⁴, Wei Lin⁵, Jun Liu⁶, Ying Zhou^1,7

¹Reproductive Medicine Center, The First Affiliated Hospital of Wenzhou Medical University, ²Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, ³Department of Obstetrics, The First Affiliated Hospital of Wenzhou Medical University, ⁴School of Laboratory Medicine and Life Science, Wenzhou Medical University, ⁵School of Pharmaceutical Science, Wenzhou Medical University, ⁶Stem Cells and Genetic Engineering Group, AgriBioscience Research Centre, Department of Economic Development, Jobs, Transport and Resources, ⁷Department of Histology and Embryology, Wenzhou Medical University

A highly promising technique to generate tissue constructs without using matrix is to culture cells in a simulated microgravity condition. Using a rotary culture system, we examined ovarian follicle growth and oocyte maturation in terms of follicle survival, morphology, growth, and oocyte function under the simulated microgravity condition.