Timothy O’Connor
Professor & Associate Head
Member, Program in Cell and Developmental Biology
Member, iCORD (Collaborations on Repair Discoveries)
PhD (University of Toronto)Associate Member, Department of Zoology Member, Program in Neuroscience
BSc (University of Toronto)
Email: timothy.oconnor@ubc.ca
Office: 604-822-9759
Lab: 604-822-1705
- Vaikakkara Chithran A, Allan DW, O’Connor TP. (2024) Adult expression of the cell adhesion protein Fasciclin 3 is required for the maintenance of adult olfactory interneurons. J Cell Science. 2024 Jun 15;137(12):261759. doi: 10.1242/jcs.261759.
- Vaikakkara Chithran A, Allan DW, O’Connor TP. (2023) Adult expression of Semaphorins and Plexins is essential for motor neuron survival. Scientific Reports 13(1):5894. doi: 10.1038/s41598-023-32943-4.
- Ganguly P, Madonsela Chao JT, Loewen CJR, O’Connor TP, Verheyen EM, Allan DW. (2021) A scalable Drosophila assay for clinical interpretation of human PTEN variants in suppression of PI3K/AKT induced cellular proliferation. PLoS Genetics. 17(9):e1009774. doi: 10.1371/journal.pgen.1009774.
- Kathryn L Post, Manuel Belmadani, Payel Ganguly, Fabian Meili, Riki Dingwall, Troy A McDiarmid, Warren M Meyers, Caitlin Herrington, Barry P Young, Daniel B Callaghan, Sanja Rogic, Matthew Edwards, Ana Niciforovic, Alessandro Cau, Catharine H Rankin, Timothy P O’Connor, Shernaz X Bamji, Christopher J Loewen, Douglas W Allan, Paul Pavlidis, Kurt Haas (2020) Multi-model functionalization of disease-associated PTEN missense mutations identifies multiple molecular mechanisms underlying protein dysfunction. Nature Communications Apr 29;11(1):2073. doi: 10.1038/s41467-020-15943-0.
- Chithran, A.V., Lett, R.M. and Timothy P. O’Connor (2019). Specific Neural Connection Formation in the Developing Nervous System(Review). Encyclopedia Life Sciences.
- Liu, R.Q., Browne, K. and T. P. O’Connor (2017) Assays to examine transmembrane semaphorin function in vitro. Methods in Molecular Biology. 1493:247-263.
- Liu RQ, Wang W, Legg A, Abramyan J, O’Connor TP (2014) Semaphorin 5B is a repellent cue for sensory afferents projecting into the developing spinal cord. Development 141:1940-9.
Further publications can be found here.
We are a small lab and in the process of winding down our research activities. Our current work is focused on completing and publishing our findings on the signalling mechanisms underlying neural circuit maintenance in the aging nervous system.
While Semaphorins and their Plexin receptors are best known for guiding axons during development, our recent work shows they play a second, unexpected role: maintaining the survival of motor neurons in the adult fly. Using temporally controlled genetic knockdown restricted to neurons after they’ve matured, we’ve found that the Sema1a–PlexA and Sema2a–PlexB signaling systems (amongst others) act on overlapping populations of adult motor neurons through parallel survival-promoting pathways, with combined loss of both producing a near-additive effect on neuronal loss. Because this knockdown is switched on only in adulthood, the resulting neurodegeneration can’t be explained by faulty developmental wiring and indicates a genuine, ongoing requirement for guidance-cue signaling long after the nervous system is built. This project is still on going.
The Lab is no longer accepting new graduate students or postdoctoral fellows, as Dr. O’Connor is winding down active research. We do take on a few undergraduate students under the supervision of Dr. Robin Vuilleumier (Research Associate) if space and time is available. Thank you for your interest in the lab’s work.