题　目：Applications of Ultrafast Laser Microsurgery and Live Tissue Imaging in Biomedical Research 

报告人：Jun Cheng (University of Illinois at Chicago, USA)
时　间：8月16日（周五），下午3:00-4:00
地　点：南校区第一实验楼406会议室

报告摘要：

  Ever since their invention, laser and optical imaging microscopy have revolutionized biomedical research. Ultrafast laser pulses to selectively ablate structures with nanometer precision has found enormous applications, such as 3D micromachining in material processing and structural-knockout in biomedical fields. Live tissue imaging makes it possible to directly study kinetics and biomechanical properties of subcellular structures within their intact microenvironment.

  Besides protein patterning by ultrafast laser irradiation, two projects are discussed in details to demonstrate the  efficacy  and  value  of  ultrafast  laser  microsurgery  in  selectively  ablating  intracellular  structures.  One project  is to  study bio-mechanistic  oscillatory movements  of mitotic  chromosomes  (known  as “directional instability”), in which  sections of a chromosome’s arms were removed by  femtosecond laser microsurgery thus  decreasing the polar-ejection force on the  chromosome. The  second project  is to  investigate  study the role  of ASC protein  aggregation during apoptosis by their  structural knockouts, which is complimentary to genetic knockout method.

  In many tissue types, stem cells reside inside their microenvironment and divide asymmetrically, i.e, one daughter cell self-renews and the other daughter cell differentiates. Using male Drosophila gonad as a model system, 3D live tissue imaging microscopy was developed to directly study the kinetics and biomechanics of subcellular  structures  during  asymmetric  stem  cell  divisions. The  results  show that  aged  germ  stem  cells uniquely re-orient their centrosomes before undergoing  asymmetric stem cell divisions, and cyst stem cells adopt the distinctive spindle repositioning mechanism to achieve asymmetric stem cell divisions.

个人简介：

•  1995年-1999年，北京大学物理系，本科

•  1999年-2002年，美国密歇根大学电子工程系，硕士

•  2002年-2006年，美国密歇根大学物理系，博士

•  2006年-2010年，美国密歇根大学生物工程系，博士后

•  2010年-现在， 美国伊利诺斯大学芝加哥分校生物工程系，助理教授