Publications: Peer-reviewed journal articles (by staff)
Assessment of heat shock and laboratory virus challenges to selectively breed for ostreid herpesvirus 1 (OsHV-1) resistance in the Pacific oyster, Crassostrea gigas
Camara MD, Yen S, Kaspar HF, Kesarcodi-Watson A, King N, Jeffs AG, Tremblay LA 2017. Assessment of heat shock and laboratory virus challenges to selectively breed for ostreid herpesvirus 1 (OsHV-1) resistance in the Pacific oyster, Crassostrea gigas. Aquaculture 469: 50-58.
DOI link here
Mass mortalities of juvenile Pacific oysters (Crassostrea gigas) in aquaculture operations have been linked to the ostreid herpes virus 1 (OsHV-1) or its variants. This oyster has heritable resilience to the virus which can provide a basis for selective breeding for higher OsHV-1 resistance, however, controlled challenge methods for improving selection response towards increased OsHV-1 resistance are required. The objective of this study was to compare the survival of sibling juvenile oysters exposed to either a laboratory virus challenge or a heat shock challenge (as proxy for the virus challenge) and the survival of the same families on two oyster farms where they were exposed to natural field conditions including the presence of OsHV-1. A strong correlation between the family rankings was observed for the two farm sites. Estimated narrow sense heritabilities (h2) on the underlying liability scale were 0.38 (on-farm survival), 0.45 (laboratory virus challenge survival) and 0.15 (heat shock challenge survival). Only on-farm survival and laboratory virus challenge had a high genetic correlation. The method for measuring heat shock resistance in juvenile oysters produced high variability in survival among families but low estimates of heritability. Overall, the results of this study indicate that the laboratory virus challenge is a simple and relatively effective tool for selective breeding specifically towards OsHV-1 resistance or as part of a controlled multi-trait program.
Statement of relevance
The OsHV-1 virus is a serious problem for commercial aquaculture of Pacific oysters in numerous countries. This paper tests two ways of evaluating oysters for resistance to OsHV-1 that can be incorporated into selective breeding programs.