Marine Biotechnology Fellowship: Characterization of the Role of Bacterial Symbionts in the Protection of Loligo Opalescens Embryos

与我们对成年阶段多细胞防御系统（如免疫系统）的了解相比，目前对早期胚胎用来逃避环境威胁的防御机制的了解还很初级。为了确保海洋生命周期中这些关键的初级阶段的生存，必须在胚胎中存在强大的生态选择压力，使生物装置能够抵抗病原体和捕食者。太平洋鱿鱼（Loligo opalescens）的卵囊为研究这种胚胎保护过程提供了一个模型系统。这些鱿鱼将它们的卵聚集在像蒙特利湾这样的浅海中。在长达一个月的怀孕期间，这些胚胎很少或根本没有受到动物、真菌或微生物的捕食。最初的研究揭示了几种不同的细菌共生体的存在，特别是与卵囊鞘相关。这些细菌显然是由与鱿鱼卵巢相连的副网膜分泌的，其中也含有共生细菌。本研究项目旨在鉴定这些微生物，并评估它们对野生鱿鱼胚胎保护的贡献。通过将原核遗传学和分子生物学与更经典的海洋生态学方法相结合，本研究将解决有关海洋胚胎防御机制和潜在治疗药物在水产养殖和医学中的应用的问题。此外，将研究的海洋细菌和真核宿主之间的相互关系的分子装置可能代表一种全球现象，对包括免疫学、细胞生物学和传染病在内的广泛学科具有影响。＊＊＊

9321532 EPEL Current understanding of the defense mechanisms utilized by early embryos to evade environmental threats is rudimentary in comparison to our knowledge of multicellular defense systems, such as the immune system, employed by adult life stages. Strong ecological selectiv pressures for biological devices to resist pathogens and predators must exist in embryos to assure survival of these critical primary stages in oceanic life cycles. The egg capsule of the Pacificc squid, Loligo opalescens, provides a model system to study such embryo protection processes. These squid deposit their eggs in large communal aggregates in shallow coastal waters such as in Monterey Bay. During their month-long gestation period these embryos endure little or no animal, fungal, or microbial predations. Initial studies revealed the presence of several distinct bacterial symbionts specifically associated with the egg capsule sheath. These bacteria apparently are secreted from the accessory nidamental gland connected to the squid ovary, which also contains symbioticbacteria. This research project aims to identify these microbes and assess their contribution to the protection of the squid embryos in the wild. By integrating prokaryotic genetics and molecular biology with more classical approaches to ocean ecology, this research will address questions concerning both marine embryo defense mechanisms and potential therapeutic agents for use in aquaculture and medicine. Additionally, the molecular devices responsible for the mutualistic relationship between marine bacteria and the eukaryotic host that will be studied may represent a global phenomenon with implications for a wide spectrum of disciplines including immunology, cell biology, and infectious disease. ***