Two Oyster Species That Show Differential Susceptibility to Virus Infection Also Show Differential Proteomic Responses to Generic dsRNA

Viral diseases are
a significant cause of mortality and morbidity
in oysters, resulting in significant economic losses. We investigated
the proteomic responses of these two species of oysters to generic
double-stranded RNAs (poly I:C and poly A:U). Analysis of proteomic
data using isobaric tags for relative and absolute quantitaion (iTRAQ)
indicated that there were significant differences in the proteomic
responses of the two oyster species resulting from this treatment.
Gene ontology analysis showed that several biological processes, cellular
components, and molecular function were unique to the different data
sets. For example, a number of proteins implicated in the TLR signaling
pathway were associated with the Saccostrea glomerata data set but were absent in the Crassostra gigas data set. These results suggest that the differences in the proteomic
responses to dsRNA may underpin the biological differences in viral
susceptibility. Molecular targets previously shown to be expressed
in C. gigas in response to OsHV1 infections
were not present in our proteomic data sets, although they were present
in the RNA extracted from the very same tissues. Taken together, our
data indicate that there are substantial disparities between transcriptomic
and proteomic responses to dsRNA challenge, and a comprehensive account
of the oysters’ biological responses to these treatments must
take into account that disparity.