Aquatic Animal Health and Biosecurity Subprogram: Identification of differentially expressed innate immune genes in the New Zealand paua (Haliotis iris) and the Australian hybrid abalone (H. laevigata X H. rubra) upon immersion challenge with the abalone herpesvirus-1 (HaHV)
CSIRO Australian Animal Health Laboratory
Abalone viral ganglioneuritis (AVG) has occurred in Victorian abalone for several years beginning from 2005/6. Later on several genetic variants of the causative agent, abalone herpesvirus (HaHV) (previously called AbHV) associated with disease outbreaks were discovered in Tasmanian processing plants. All Australian abalone species tested to date have been shown to be susceptible to HaHV infection and to the disease it causes (Corbeil et al., 2016, Diseases of Aquatic Organisms 119:101-106). In addition, a recent study revealed that the New Zealand paua (H. iris) is resistant to AVG when challenged with the virus via intra-muscular injection and immersion (Corbeil et al., 2017, Journal of Invertebrate Pathology 146:31-35). The mechanism(s) of protection present in the paua are not known but are possibly based on innate immune genes that are expressed in paua but not expressed (or are absent) in Australian abalone species. Identifying the mechanisms of protection would provide a knowledge based platform that could lead to the development of hybrid abalone possessing resistance traits and/or to the development of immunotherapeutic molecules that could protect Australian abalone species. This project aims to address this knowledge gap and is relevant to all jurisdictions with abalone fisheries. Access to bio-secure aquarium facilities provides CSIRO-AAHL with a unique capability to investigate what genetic factors influence disease resistance in paua (exotic species), and carry out molecular gene characterisation.
1. Define the time-line of an anti-viral response in the paua and Australian hybrid abalone for the first-time, utilising real-time PCR, and a set of known anti-viral effector genes.
2. Through mRNA sequencing and genomic analysis, identify early genes expressed in paua and Australian hybrid abalone upon HaHV immersion challenge.
3. Establish an immune signature in the early response of the host to the virus that differs between the paua and Australian hybrid abalone, to determine key immune players in HaHV resistance.