NCCP: Understanding the genetics and genomics of carp strains and susceptibility to CyHV-3
CSIRO Australian Animal Health Laboratory
While the assumptions used in the NCCP epidemiological model use best available knowledge to inform assumptions for infection rates among wild carp populations in Australia, this knowledge is based on incomplete evidence. For example, it is not known through direct experimentation the rates at which the four carp strains identified in Australia will be resistant to CyHV-3. While historical records of past carp introductions indicate that the strain known to be resistant (Amur River carp) was not among Australian releases, there is not yet a comprehensive identification of carp strains and corresponding resistance. While direct testing of resistance of Australian strains through infection and genetic back-crossing trials would provide the greatest level of confidence, this approach would be both time-consuming, costly, and would need to compete for primacy with other critical experiments at the only facility in Australia able to handle CyHV-3. viz. the Australian Animal Health Laboratory. However, a different approach, using genetics and genomics can provide a much higher level of information and confidence than is currently available, while significantly avoiding the drawbacks of a direct approach. It is important to build as much confidence into epidemiological model parameters and assumptions as possible in order to: 1. Inform the primary objective of the NCCP to determine the feasibility of using CyHV-3 as a biocontrol in Australia 2. Validate or refine model outputs to best inform implementation and management planning 3. Increase confidence of the public and science community to reinforce support for planning and decision-making
1. Determine the likely genes responsible for resistance of carp to CyHV-3.
2. Undertake sequencing of strains of carp and hybrids present in Australia and overseas
3. Undertake bioinformatics analyses to assess the likelihood of resistance genes being present in Australian strains