GENETIC IMPROVEMENT OF EASTERN OYSTERS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: ANIMAL HEALTH
• Reporting Frequency: Annual
• Accession No.: 1021665
• Project Start Date: Nov 19, 2019
• Project End Date: Sep 30, 2024
• Program Code: [(N/A)]- (N/A)

Recipient Organization
RUTGERS, THE STATE UNIVERSITY OF NEW JERSEY
3 RUTGERS PLZA
NEW BRUNSWICK,NJ 08901-8559

Performing Department
Haskin Shellfish Research Laboratory

Non Technical Summary
The Eastern oyster (Crassostrea virginica) is one of the most important aquaculture species in the US. Oyster aquaculture is friendly to the environment as it does involve feeding and cultured oysters filter the water and remove carbon. Eastern oyster aquaculture has been growing in the past decades. However, the sustainable development of Eastern oyster aquaculture faces some challenges, where genetic research and development can be part of the solution. First, Eastern oyster populations along much of the Atlantic coast have been devastated by three diseases: Dermo (caused by Perkinsus marinus), MSX (Haplosporidium nelsoni) and ROD (caused by Roseovarius crassostreae). Each of these diseases can caused severe mortalities in naïve oysters. Climate change such as warming and acidification of the oceans creates stress to oysters making them more susceptible to diseases. Warming oceans may cause expansion and more frequent outbreaks of certain diseases. The development of disease resistant strains is critically important for the oyster aquaculture industry. Secondly, most oyster stocks in production have only limited history of domestication and clack desirable characteristics for aquaculture. The Eastern oyster grows slowly and it often takes 24 - 36 months to reach market sizes. Stocks with superior growth will greatly benefit oyster farmers.Genetic improvement can contribute to the sustainability of oyster aquaculture by making cultured stocks more resilient and suitable for aquaculture. Rutgers University has been breeding Eastern oysters by traditional selection since 1960. The resultant strains have shown significant improvements in disease resistance and growth. However, traditional selection is slow and inefficient. The advent of genomics and modern breeding technologies offers new promises to genetic improvement. The Eastern oyster genome has been sequenced recently, which paves the way for in-depth studies of oyster biology and genome-based breeding. The development of sterile and fast-growing triploids (with three sets of chromosomes) can also greatly benefit oyster aquaculture.The goal of this project is to develop a research program in oyster genetics and breeding using advanced genetic approaches to serve the oyster aquaculture industry. This project aims to understand and improve disease resistance and growth of the Eastern oyster through genomic and cytogenetic approaches.

Animal Health Component

40%

Research Effort Categories

Basic

20%

Applied

40%

Developmental

40%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
303	0811	1081	50%
311	0811	1080	50%

Knowledge Area
303 - Genetic Improvement of Animals; 311 - Animal Diseases;

Subject Of Investigation
0811 - Shellfish;

Field Of Science
1081 - Breeding; 1080 - Genetics;

Keywords

oysters

aquaculture

disease resistance

genetic improvement

genomic selection

triploids

Goals / Objectives
The goal of this project is to improve Eastern oyster stocks for aquaculture. We hope to understand and improve disease resistance and growth in the eastern oyster using advanced genetic and genomic approaches. The specific objectives are to:1). Understand and improve disease resistance through advanced genomics; and2). Develop and improve triploid Eastern oysters for the Northeastern region.

Project Methods
This project will use genome-wide association studies to establish association between genotypes and production traits. The associations will be used to calculate a genomic estimated breeding value for each parent oysters. Oysters will high and low breeding values will be selected to produce the next generation. Progeny from genomic selection will be produced and deployed for field evaluation. Oysters produced from parents with high breeding values are expected to out-perform control groups. Triploid oysters will be produced using new tetraploid lines developed with previous USDA funding. Hybrid triploids will be produced using diploids used by oyster farmers and tetraploids. These triploids will be deployed on farms in the Northeastern region. The triploids are expected to out-perform local diploids and bring more returns to oyster farmers.

Progress 11/19/19 to 09/30/20

Outputs
Target Audience:Shellfish farmers, aquaculturists, shellfish breeders, shellfish researchers, students and educators, people who are interested in shellfish biology and seafood production. Changes/Problems:The COVID-19 pandemic caused delaysand cancelation of some laboratory and field work, which should not significantly affect the overall plan of this project. What opportunities for training and professional development has the project provided?The project provided research opportunities to three graduate students. It also provided research experience toone undergraduate student and five recent college graduates who worked as summer interns. How have the results been disseminated to communities of interest?Some of the results have been disseminated to the research and shellfish aquaculture community through seminars and meetings. The SNP array will be made available to the research community as soon as they are produced. What do you plan to do during the next reporting period to accomplish the goals?We plan to use the SNP array to study genetics of disease resistance in the eastern oyster, to complete field evaluation of diploid and triploid stocks and to disseminate the new tools, information and stocks to shellfish community and farming industry.

Impacts
What was accomplished under these goals? We worked as part of the Eastern Oyster Breeding Consortium and secured funding from the Atlantic States Marine Fisheries Commission for a major project titled "From sequence to consequence: genomic selection to expand and improve selective breeding for the Eastern oyster". The projects aims to develop a high-throughput genotyping platform for genomic analyses and selection. A high-density 600k SNP array has been designed and is being manufactured. The array is expected to enable genome-wide association study and genomic selection for disease resistance. We produced diploid and triploid oysters from diverse genetic backgrounds and deployed them in coastal bays of New Jersey. We hope to identify which stocks do better in high salinity environments in coastal bays. Previously, our breeding efforts have been focused on disease resistance in low salinity areas of Delaware Bay. Oyster stocks that are better adapted to high salinity waters may be used to diversify and enhance shellfish aquaculture in coastal waters that has been dominated by hard clam culture. We also produced inbred and bybrid families of the eastern oysterin summer of 2020. These families have been deployed in the field. We plan to use these families to study the effects on inbreeding and the molecular bases of heterosis.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Jiao, Y., Y. Cao, Z. Zheng, M. Liu & X. Guo. 2019. Massive expansion and diversity of nicotinic acetylcholine receptors in lophotrochozoans. BMC Genomics 20:937. https://doi.org/10.1186/s12864-019-6278-9
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Acquafredda, M. P., X. Guo & D. Munroe. Exploring the Feasibility of Selectively Breeding Farmed Atlantic Surfclams Spisula solidissima for Greater Heat Tolerance. North American Journal of Aquaculture, online. https://doi.org/10.1002/naaq.10168
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Liu, J., Q. Zeng, H. Wang, M. Teng, X. Guo, Z. Bao and S. Wang. 2020. The complete mitochondrial genome and phylogenetic analysis of the dwarf surf clam Mulinia lateralis. Mitochondrial DNA Part B 5(1):140-141. https://doi.org/10.1080/23802359.2019.1698352