Project Number: 5358-31000-003-00
Project Type: Appropriated

Start Date: Mar 01, 2010
End Date: Feb 28, 2015

Objective:
Objective 1: Assess the potential for genetic gain, and trade-offs among economically important traits in currently available Pacific oyster germplasm in order to develop a framework for informed decisions regarding alternative selective breeding strategies. Sub-objective 1.A. Estimate the additive genetic, non-additive genetic, and environmental covariance matrices for larval, nursery, and field performance in currently available germplasm of the Pacific oyster using a multi-year animal model approach. Sub-objective 1.B. Use the estimates obtained in Sub-objective 1.A. to design an efficient genetic improvement strategy for Pacific oysters. Objective 2: Evaluate and optimize mixed-family breeding strategies for Pacific oysters. Sub-objective 2.A. Determine at which stage larval progeny derived from controlled crosses of Pacific oysters can be mixed in equal proportions and not have those proportions drastically skewed at the field plant-out stage. Sub-objective 2.B. Compare the results and costs of mixed family selection protocols to current procedures in which families are reared separately from spawn to harvest. Objective 3: Identify genetic markers for economically important traits in Pacific oysters to enable marker-assisted selection. Sub-objective 3.A. Examine the relationship between among-family variance in the expression levels of previously identified candidate genes and family-specific growth and survival in the field. Sub-objective 3.B. Use standard QTL mapping approaches and quantitative assays of the levels of expression of candidate genes to identify regions of the Pacific oyster genome that control the transcription of the most promising candidate genes from Objective 3.A.

Approach:
Utilize quantitative and molecular genetics techniques to elucidate the genetic architecture of, map quantitative trait loci for, and identify expression QTL for candidate genes that control economically important traits in cultured Pacific oysters. Utilize this new information to integrate rigorously-estimated breeding values and marker-assisted selection into the NIFA-funded Molluscan Broodstock Program, which currently selects only on post-larval yield using among-family selection. Explore the utility of marker-based pedigree reconstruction from mixed-family evaluations to mitigate family-specific environmental effects on families reared separately without replication during the larval and nursery stages and family-specific density effects on growth during field trials caused by differential survival of families. FY02 Program Increase $216,000. Add 1 SY. FY04 Program Increase $120,783. Replacing 5358-31000-001-00D (2/05). Replacing 5358-31000-002-00D (2/10). Program Increase $120,000 (2/10) to identify genetic and non-genetic factors influencing immunity in Atlantic oysters.