Nellie Gagné

Research scientist

My main research focus is concentrated on using molecular biology to detect RNA/DNA from living organisms and viruses. One of my roles is to design and validation molecular assays to detect viral pathogens in fish, parasites in mollusc, and viruses and bacterias in crustaceans. I also concentrate my research on the detection of living organisms through the DNA they leave in the aquatic environment (eDNA). Salmon and other fish species are detectable by analysing  DNA traces from a water sample. For other organisms like insect larvae, it is possible to use a DNA based method to identify them from complex samples. In a way, DNA identification is used for taxonomical identification. When possible, the amount of DNA detected can be related to the abundance of the species in the environment. It is important however to understand how DNA is released, how it moves and how best to detect it if species presence are assessed by these methods.

Current research and/or projects

As part of the National Aquatic Animal Health Program (NAAHP), I lead a group of enthusiastic scientist and technicians, dedicated to deliver the diagnostic and research component of the program. Our tests are ‘home made’ and require us to develop and validate assays for the diagnostic of various fish and shellfish diseases. Using molecular biology methods, we trace the DNA (or RNA) signature of the pathogens in the samples submitted to us, and also confirm suspicious findings from other laboratories of our section, using various methods like DNA sequencing.

Molecular biology is a great tool. We can “modify” the fate of a cell, and check what happens. We can “design” our own pieces of DNA. It is not well known, but fish are vaccinated against some devastating diseases, but developing new vaccines is long. Our lab has a special interest in this field, and we work at developing new “DNA vaccines” while in parallel, we study the fish immune response to these same pathogen. Occasionally, we will also take on a challenge, eg. finding a way to quickly determine the proportion of two scallops species in a spat collector…or identifying an unknown pathogen.

Research and/or project statements

Education and awards

BSc Biology, MSc Food Science, UQAR, McGill, 1993

Key publications

  1. Charles G. B. Caraguel,1 Henrik Stryhn, Nellie Gagné, Ian R. Dohoo, K. Larry Hammell (2011) Selection of a cutoff value for real-time polymerase chain reaction results to fit a diagnostic purpose: analytical and epidemiologic approaches. J Vet Diagn Invest 23:2–15
  2. LeBlanc F, Laflamme M, Gagné N (2010) . Genetic markers of the immune response of Atlantic salmon (Salmo salar) to infectious salmon anemia virus (ISAV). Fish Shellfish Immunol. Aug;29(2):217-32
  3. N Chérif, N Gagné, D Groman, F Kibenge, T Iwamoto, C Yason and S Hammami (2010) Complete sequencing of Tunisian redspotted grouper nervous necrosis virus betanodavirus capsid gene and RNA-dependent RNA polymerase gene. J.Fish Dis. 33: 231-240
  4. Caraguel C, Stryhn H, Gagné N, Dohoo I and Hammell L (2009) Traditional descriptive analysis and novel visual representation of diagnostic repeatability and reproducibility: application to an infectious salmon anaemia virus RT-PCR assay. Prevent. Vet. Med. 92: 9-19
  5. Ritchie RJ, McDonald JT, Glebe B, Yound-Lai W, Johnsen E and Gagné N (2009) Comparative virulence of Infectious salmon anaemia virus (ISAV) isolates in Atlantic salmon (Salmo salar L.). J. Fish Diseases, 32:157-171
  6. Johnson A, Binette SL, Cook-Versloot M, Beattie M, McGeachy S, Gagné N, McDonald JT and Ritchie R (2008). Association between ISAV mortalities and ISAV molecular type in the Bay of Fundy, Canada. Canadian Technical Report of Fisheries Aquatic Sciences 2782
  7. N. Gagné*, A.-M. MacKinnon, L. Boston, B. Souter, M. Cook, S. Griffiths and G. Olivier (2007) Isolation of viral hemorrhagic septicaemia virus (VHSV) from mummichogs, sticklebacks, striped bass and brown trout in eastern Canada. J. Fish Diseases, 30(4):213-23
  8. Ritchie, R.J. and Gagné, N. 2006. Development of a strand-specific RT-PCR assay for ISAV.
  9. Gagné N*, Cochennec N, Stephenson M, McGladdery S, Meyer, GR, Bower SM. (2008) First report of a Mikrocytos-like parasite in European oysters Ostrea edulis L.from Canada after transport and quarantine in France. Dis. Aquat. Org.; 80(1):27-35
  10. Gagné N, Johnson SC, Cook-Versloot M, MacKinnon A-M and Olivier G (2005). Detection and characterization of nodavirus in several marine fish species from the Northeastern Atlantic. Bull Aquac Ass Can 104 (2): 57-64
  11. McClure CA, Hammell KL, Dohoo IR, Gagné N (2004) Lack of evidence of infectious salmon anemia virus in pollock Pollachius virens cohabitating with infected farmed Atlantic salmon Salmo salar. Dis Aquat Org 61:149-152
  12. Nérette, P., Dohoo, I., Hammell, L., Gagné, N., Barbash, P., MacLean, S., Yason, C. (2005)
  13. Harmon P, MacKinnon AM, Boston L, and Gagné N (2004). Nodavirus in Haddock, Melanogrammus aeglefinus. AAC Spec. Pub. No.8, p.43-46
  14. Gagné N, Johnson SC, Cook-Versloot M, MacKinnon AM, Olivier G (2004) Molecular detection and characterization of nodavirus in several marine fish species from the northeastern Atlantic. Dis Aquat Org 62(3):181-189.