We are using C. elegans as a model system to study cellular and molecular mechanisms underlying neuronal development and regeneration. The C. elegans nervous system is composed of 302 neurons with a complete map of all axon trajectories and synaptic connections. The transparency and small size of C. elegans allows us to target any axon with femtosecond laser ablation, as well as visualize axonal development and axonal regeneration in live animals using time-lapse fluorescence microscopy. Femtosecond laser ablation is a new optical scalpel with exquisite precision and reproducibility. The nanometer precision of femtosecond laser ablation, as well as the million-fold shorter exposure interval, allows us to snip individual nerve fibers without collateral damages to the cell body or neighboring fibers. C. elegans has very powerful genetic tools to illustrate basic biological mechanisms as exemplified by C. elegans biologists winning 2002 Nobel Prize in programmed cell death and again past year Nobel Prize in RNAi. We thus have a unique opportunity to apply powerful genetic and optical approaches in C. elegans to dissect brain wiring and rewiring mechanisms.
References:
Gabel, CV, Antonie, F, Chuang, C-F, Samuel, AD, and Chang, C. Distinct cellular and molecular mechanisms mediate initial axon development and adult-stage axon regeneration in C. elegans. Development (2008) 135: 1129-1136.
Chang C, Adler C, Krause M, Clark S, Hao J, Gertler F, Tessier-Lavigne M, Bargmann CI. MIG-10/Lamellipodin and the lipid modulator AGE-1/PI3K promote axon guidance and outgrowth in response to Slit and Netrin. Current Biology (2006) 16: 1-9.
Samuel A, Chung SH, Clark DA, Gabel CV, Chang C, Murthy V and Mazur E. Femtosecond laser dissection in C. elegans neural circuits. Proceedings of The International Society for Optical Engineering (2006) 6108: 1-6.
Chang C, Yu TW, Bargmann CI, Tessier-Lavigne M. Inhibition of Netrin-mediated axon attraction by a receptor protein tyrosine phosphatase. Science (2004) 305: 103-106.
Qualifications:
Prior experience in C. elegans is helpful but not essential. Applicants should have a Ph.D. in genetics, cell biology, molecular biology, neurobiology, or biochemistry and are familiar with molecular biology techniques.
Contact Information :
Interested candidates please send a brief cover letter describing research experience, CV, and names and contact information of two references to Dr. Chieh Chang at chieh.chang@mcgill.ca.
