Sustainable food security through aquaculture: Establishment of algal technology for optimal aquaculture growth and health.

水产养殖为许多发展中国家提供了可持续的粮食安全。水产养殖病害增加了成本，降低了产量。因此，开发具有成本效益的方法来预防疾病迫在眉睫。然而，这些技术还处于起步阶段。在该项目的第一阶段，将评估以藻类作为单一物种和混合物种微藻饲料饲养的模式双壳类软体动物的生长和性能。微藻将在改良的环境中饲养，以便自然地影响生化表型的变化和潜在的营养价值。这些藻类将被用作比较实验的食物来源，以比较欧洲扁平牡蛎Ostrea edulis、太平洋牡蛎Magallana gigas和蓝贻贝Mytilus edulis对生长、代谢、生殖投资和免疫功能的影响；欧洲三种主要的养殖双壳类动物。在第二阶段，该项目将考虑使用转基因微藻物种作为干扰Magallana gigas牡蛎疱疹病毒（OsHV1）复制周期的机制，Magallana gigas是欧洲养殖太平洋牡蛎的非外来病原体（Rogers et al., 2019）。使用既定的方法（Charoonnart et al., 2019），我们将培养含有针对关键牡蛎疱疹病毒病毒基因的dsRNA盒的转基因微藻。我们将探索这种基于饮食的RNAi平台的潜力，以防止病毒在英国养殖床上的同居太平洋牡蛎中复制。病毒复制将通过评估病毒诱导的组织病理学和通过病毒基因转录物的绝对定量PCR检测（Hauton等，2007）来量化。

Aquaculture offers sustainable food security to many developing countries. Aquaculture disease increases costs and decreases yields. The development of cost effective solutions to prevent disease is therefore pressing. Such technologies are however in their infancy. In stage 1 of this project the growth and performance of model bivalve molluscs reared on algal as single species and mixed species microalgal diets will be assessed. Microalgae will be reared in amended environments in order to naturally effect changes in the biochemical phenotype and potential nutritional value. These algae will be used as a food source in comparative experiments to compare the effects on growth, metabolism, reproductive investment, and immune function in European flat oysters Ostrea edulis, Pacific oysters Magallana gigas, and blue mussels Mytilus edulis; the three main cultured bivalve species in Europe. In a second phase, the project will consider the use of genetically modified microalgal species as a mechanism to interfere with the replication cycle of oyster herpes virus (OsHV1) of Magallana gigas, a non-exotic pathogen of cultured Pacific oysters in Europe (Rogers et al., 2019). Using established methodology (Charoonnart et al., 2019), we will culture genetically modified microalgae that contain a dsRNA cassette targeting a key oyster herpes virus viral gene. We will explore the potential of this as a diet based platform for the delivery of RNAi to prevent viral replication in cohabiting Pacific oysters in cultured beds in the UK. Viral replication will be quantified through assessments of viral induced histopathology and through absolute quantitative PCR detection (Hauton et al., 2007) of viral gene transcripts.