OCE-PRF Track 1 (Broadening Participation): Evolutionary ecology of the "living solar panel" - how photosymbioses influence diversification of a marine bivalve lineage

OCE-PRF Track 1（扩大参与）：“活太阳能电池板”的进化生态学 - 光共生如何影响海洋双壳类谱系的多样化

• 批准号: 1420967
• 金额: $ 17.4万
• 依托单位: Li Jingchun
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1420967&HistoricalAwards=false
• 关键词: OCE; PRF; Track; Broadening; Participation

In this two year postdoctoral research fellowship, the fellow will investigate how photosymbiotic associations shape marine biodiversification using the bivalve subfamily Fraginae as a study system. Research results will contribute to our fundamental knowledge of biodiversity, macroevolution and marine ecology. The project will be conducted under the mentorship of Dr. Colleen Cavanaugh at Harvard University. The project includes multi-level outreach activities that are specifically designed to broaden participation of underrepresented groups in ocean sciences.Photosymbiotic associations between invertebrate hosts and photosynthetic dinoflagellates are crucial to the trophic and structural integrity of coral reef ecosystems. Although extensive efforts have been devoted to study the short-term ecological interactions between animal hosts and their symbionts, the effects of photosymbiosis on long-term evolutionary dynamics of marine metazoans are less well understood. This is partially because most marine photosymbiotic associations are ancient (e.g., arising more than 200 MYA for corals). The hosts' present diversities and genomes are highly modified by long, complex evolutionary histories; this makes it difficult to trace specific changes due to photosymbioses. The bivalve subfamily Fraginae is an apt system to address this topic because it contains an exclusive photosymbiotic lineage that diverged recently (7 MYA) from its non-symbiotic sister groups. Species in this group exhibit remarkable ecological and morphological adaptations to the photosymbiotic lifestyle. They occupy nutrient-deficient habitats where non-symbiotic species do not occur. Some species possess greatly flattened, solar-panel-like shells to enhance sunlight exposure to the symbionts, or bear microstructural shell features which function as light condensing lenses. To advance understanding of these photosymbiotic associations, the fellow will investigate evolutionary impacts of photosymbioses on Fraginae at two distinct levels. At a macroevolutionary level, patterns of lineage diversification and shell morphological evolution will be compared between the photosymbiotic and non-photosymbiotic lineages using phylogenetic comparative analyses. At a genomic level, comparative transcriptome analyses will be performed on twelve Fraginae species collected from the Indo-west Pacific and Atlantic oceans. Candidate genes involved in the establishment of photosymbioses will be identified and their functions in the hosts' physiological pathways and shell formations will be explored.

在这个为期两年的博士后研究奖学金，研究员将调查光共生协会如何塑造海洋生物多样性使用双壳类亚科Fraginae作为一个研究系统。研究成果将有助于我们对生物多样性、宏观进化和海洋生态学的基本认识。该项目将在哈佛大学的科琳·卡瓦诺博士的指导下进行。该项目包括多层次的推广活动，其具体目的是扩大代表性不足的群体对海洋科学的参与，无脊椎动物宿主和光合腰鞭毛虫之间的光合共生关系对珊瑚礁生态系统的营养和结构完整性至关重要。虽然人们已经做了大量的努力来研究动物宿主和它们的共生体之间的短期生态相互作用，但光共生对海洋后生动物长期进化动力学的影响还不太清楚。这部分是因为大多数海洋光共生协会是古老的（例如，超过200 MYA的珊瑚）。宿主目前的染色体和基因组被漫长而复杂的进化历史高度修改;这使得很难追踪由于光共生引起的特定变化。Fraginae的双壳类亚科是一个适当的系统来解决这个问题，因为它包含了一个独特的光共生谱系，最近（7 MYA）从其非共生的姐妹群体。这组物种表现出显着的生态和形态适应光共生的生活方式。它们占据着营养缺乏的栖息地，那里没有非共生物种。一些物种拥有非常扁平的太阳能电池板状外壳，以增强共生体的阳光照射，或者具有微结构外壳特征，其功能是聚光透镜。为了进一步了解这些光共生协会，该研究员将在两个不同的水平上研究光共生对Fraginae的进化影响。在宏观进化水平上，谱系多样化和壳形态进化的模式之间的光共生和非光共生谱系系统发育比较分析进行比较。在基因组水平上，比较转录组分析将进行12个Fraginae物种从印度西太平洋和大西洋。将确定参与建立光共生的候选基因，并探索其在宿主生理途径和壳形成中的功能。