Understanding the effects of environmental parameters on endosymbiotic relationship in cnidarians

珊瑚礁生态系统是生物多样性异常丰富的生境。它们在沿海生态系统中的生态成功是由于它们与共生藻属单细胞甲藻的内共生关系。由于全球气候变化导致的珊瑚白化，全世界的珊瑚礁都在减少。珊瑚呈现多种多样的共生藻群落，这在很大程度上取决于生态条件，包括海面以下的深度。虽然珊瑚礁的生态学已被广泛研究，但对影响这一关键内共生的因素却知之甚少。与石珊瑚一样，海葵也有共生的共生甲藻物种，并构成实验上易于处理的模型来研究刺胞藻甲藻共生的各个方面。海葵可以栖息在不同深度的海面，可能是通过改变它们与共生藻类型的联系。然而，迄今为止，很少有研究调查的生态生理和遗传多样性的共生藻在海葵。本计画旨在研究海葵共生藻的天然深度分布。这将使我们能够了解刺胞动物如何适应不同的深度，改变他们的协会与共生藻分支。研究方法海葵样本（Anemonia viridis和Aiptasia couchii）将从不同深度收集。将在采集点深处记录环境参数（光谱辐照度、水温、盐度、氧饱和度、叶绿素荧光和光强度（光合有效辐射））。将处理组织样本，以使用LUNA自动细胞计数器测量共生藻密度。将通过PCR扩增核糖体内转录间隔区2区（ITS2）进行基因分型来鉴定共生藻属。我们将进行实地实验，借此控制海葵的垂直分布。这将让我们观察是否改变海葵深度可以影响共生藻的组成和密度。培训I）现场收集和测量物理化学参数。二）实验水族馆和畜牧业的建设和维护。二）分子生物学工具和生物信息学。三）先进的显微镜。实验设计、数据分析、批判性思维、科学写作。

Coral reef ecosystems constitute habitats of exceptional biodiversity. Their ecological success in costal ecosystem is owed to their endosymbiotic relation with unicellular dinoflagellate algae belonging to the Symbiodinium genus. Coral reefs are declining worldwide due to coral bleaching associated with global climate change. Corals present a diverse range of Symbiodinium communities, which depend to a great extent on ecological conditions, including depth below the sea surface. While the ecology of coral reefs has been extensively studied, the factors affecting this critical endosymbiosis are less well understood. Like stony corals, anemones have symbiotic Symbiodinium species and constitute experimentally tractable models to investigate aspects of the cnidarian-dinoflagellate symbiosis. Anemones can inhabit different depths from the sea surface, possibly by altering their association with Symbiodinium type. To date, however, few studies have investigated the ecophysiology and genetic diversity of Symbiodinium in anemones. This project aims to study the natural depth distribution of anemone Symbiodinium. This will enable us to understand how cnidarians acclimatize to different depths by changing their association with Symbiodinium clades. Research methodologySea anemone samples (Anemonia viridis, and Aiptasia couchii) will be collected from different depths. Environmental parameters (spectral irradiance, water temperature, salinity, oxygen saturation, chlorophyll fluorescence, and light intensity (photosynthetic active radiation) will be recorded at the collection site depths. Tissue samples will be processed to measure the Symbiodinium densities using a LUNA automated cell counter. Symbiodinium species will be identified by genotyping by PCR amplifying the ribosomal internal transcribed spacer 2 region (ITS2). We will carry out field experiments whereby the vertical distribution of anemones will be manipulated. That will let us observe whether altering the anemone depth can influence the Symbiodinium composition and density.TrainingI) Field collection and measurement of physico-chemical parameters in situ. II) Construction and maintenance of experimental aquaria and animal husbandry.II) Molecular biology tools and bioinformatics.III) Advanced microscopy. IV) Experimental design, data analysis, critical thinking, scientific writing.