Research

The overall goal of the laboratory is to understand the role of ligand-gated chloride channels (LGCCs) in parasitic nematodes such as Haemonchus contortus. Compared to the free living nematode Caenhorhabditis elegans, there is relatively little known about the function of these receptors in parasitic nematodes. However, since both nematodes are phylogenetically related (both in clade V) many of the LGCC gene sequences present in C. elegans are also found in H. contortus. This allows for some interesting comparisons between the function of LGCCs homologues between a free-living nematode C. elegans verses a parasitic nematode, H. contortus.

 

 

Recent Work

Hco-GGR3: A Dopamine-gated Ion Channel: Immunolocalization of HcGGR3 in adult female H. contortus. Confocal image of the head region of a female showing the localization of HcGGR3 around the deirids. The same worm is shown under fluorescence and light microscopy. The light microscopy image clearly shows the spine-like cervical papillae.

Recent Graduates

Vijay Rao (PhD, 2010)

Thesis Title: Characterization of novel ligand-gated chloride channel subunits from Haemonchus contortus

Current position: Post-doctoral fellow (Montreal Neurological Institute)

 

Michael Accardi (MSc, 2010)

Thesis Title: Molecular characterization of the binding site of nematode GABAA receptors

Current position: PhD student (McGill University)

 

David Brown (MSc, 2010)

Thesis Title: The pharmacological characterization of Hco-UNC-49, a GABA-gated chloride channel from the parasitic nematode Haemonchus contortus

Current position: PhD student (University of Toronto)

 

Salma Siddiqui (MSc, 2009)

Thesis Title: Molecular characterization of GABA receptor subunits from Haemonchus contortus

Current position: Environmental Technician

 

 

 

 

The Hco-UNC-49 GABA binding site. Left) Model of the Hco-UNC-49B homodimer interface. The binding pocket is formed through the interactions of the six discontinuous loops indicated: Loops A-C (in grey) on the principle subunit and Loops D-F (in black) on the secondary subunit. The GABA molecule can be seen docked near the center of the loops. Right) GABA docked within the putative binding pocket of an Hco-UNC-49B homodimer.

Hco-LGC-55: A Tyramine-gated Chloride Channel. Electrophysiological trace depicting the response of Hco-LGC-55 expressed in X. laevis oocytes to the application of TA (tyramine), OA (octopamine), 5-HT (Serotonin), Ach (acetylcholine) and DA (dopamine).

200nA

20s

TA

OA

5HT

Ach

DA