Understanding the effects of environmental parameters on endosymbiotic relationship in cnidarians

珊瑚礁生态系统构成了非同寻常的生物多样性栖息地。它们在沿海生态系统中的生态成功归功于它们与属于共生属的单细胞鞭毛藻的内共生关系。由于与全球气候变化相关的珊瑚白化，世界范围内的珊瑚礁正在减少。珊瑚呈现出多种多样的共生群落，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，但影响这种关键内共生关系的因素却鲜为人知。像石珊瑚一样，海葵也有共生的共生物种，并构成了实验可处理的模型来研究刺胞动物-鞭毛动物共生的各个方面。海葵可以栖息在离海面不同深度的地方，可能是通过改变它们与共生菌类型的联系。然而，迄今为止，对海葵共生菌的生理生态和遗传多样性研究较少。本项目旨在研究海葵共生菌的自然深度分布。这将使我们了解刺胞动物如何通过改变与共生枝的联系来适应不同的深度。研究方法从不同深度采集海葵样品（Anemonia viridis, Aiptasia couchii）。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））将在采集点深度记录。将处理组织样本，使用LUNA自动细胞计数器测量共生菌密度。共生菌种将通过PCR扩增核糖体内转录间隔区2 （ITS2）进行基因分型鉴定。我们将进行实地实验，操纵海葵的垂直分布。这将让我们观察改变海葵的深度是否会影响共生菌的组成和密度。1)现场采集和测量理化参数。二、实验水族馆、实验畜牧业的建设与维护。II)分子生物学工具和生物信息学。III)高级显微术。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.