Project Number: 8030-31000-004-12-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2015
End Date: Aug 30, 2020
To 1) Characterize disease-tolerant/resistant phenotypes among selectively bred eastern oyster families using laboratory challenges and gene expression profiling. 2) Distinguish between mechanisms of disease resistance and tolerance among families. This information will also be used to identify candidate genes associated with disease resistance/tolerance and contribute to marker-assisted selection efforts.
In parallel with work being conducted by ARS scientists, selectively bred eastern oyster families will be challenged with the Dermo-disease causing parasite, Perkinsus marinus by feeding (ARS scientists are challenging oysters by injection of the parasite directly into tissue). The two modes of challenge are intended to distinguish between an oyster’s response to an established infection (disease tolerance) and its ability to prevent an infection from becoming established (disease resistance). Challenged oysters will be monitored for mortality and tissue parasite load daily. In addition, a subsample of oysters from each family will be censored at 4 carefully chosen timepoints in order to characterize the response to disease exposure over time. Material collected from censored oysters will be processed, sequenced, and analyzed according to RNAseq methodology. Gene expression profiles will be compared among the two modes of challenge as well as among families and will be used to further define disease-resistant and tolerant phenotypes. Measures of disease-resistant/tolerant phenotype beyond survival will be used in eastern oyster breeding programs. In addition, differential expression among susceptible and resistant oyster families will result in a list of candidate genes that can be further tested for their association with phenotype. Genes associated with phenotype can be used to enhance current breeding programs by including marker-assisted selection techniques.