Survey of Small Coccoid Eukaryotic Algae in Open Oceans

公海小型球状真核藻类的调查

• 批准号: 0206590
• 负责人: Robert Andersen
• 金额: $ 25万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0206590&HistoricalAwards=false
• 关键词: Survey; Small; Coccoid; Eukaryotic; Algae

The open oceans cover 66% of the earth's surface, and the primary producers are primarily tiny coccoid organisms that are very abundant. At any one instant in time, these cells are so numerous that if they were arranged as a packed mass in the shape of a standard 1 x 12 board, this plank would stretch from the earth to the moon. Furthermore, these cells divide approximately once per day, thereby producing a new plank each day. Unlike forests, where dividing cells accumulate in the tree for 100 or more years, these tiny plants of the ocean are quickly eaten. That is, the phytoplankters directly or indirectly feed the fishes, shrimp, whales, etc., so that this amazing "plank to the moon" is produced and eaten daily. Consequently, the ocean waters appear transparent and no forest-like biomass accumulates. Of these tiny organisms, the eukaryotic algae are an important component. However, they have a very simple morphology and are nearly impossible to identify using either light or electron microscopy. Although very similar in appearance (little spherical cells), from DNA studies it is obvious that these organisms represent several very different evolutionary groups. It has only recently become apparent that molecular studies involving gene sequence analysis are needed to understand this biodiversity. Culture collections, especially the Provasoli-Guillard National Center for Culture of Marine Phytoplankton (CCMP) at the Bigelow Laboratory, hold numerous strains of unidentified tiny coccoid oceanic algae from the blue water regions of the Atlantic, Pacific and Indian Oceans. In this study by Dr. Robert Andersen, these cultures and additional samples will be examined to assess oceanic biodiversity. The proposed research will utilize nuclear ribosomal gene sequences to identify and classify these diverse organisms. Cryptic species complexes will be studied using additional gene sequences (for example, genes of photosynthetic enzymes). The species composition in different oceans, as well as for different regions of the same ocean, will be compared. At present, it is unknown whether the Atlantic, Pacific and Indian Oceans have similar or different species of these abundant tiny eukaryotic coccoid algae. The results of this study will contribute to our knowledge of ocean ecosystems and their productivity. Furthermore, preliminary studies have shown that some of these tiny algae produce compounds that are beneficial for human health. For example, the newly discovered oceanic pinguiophytes produce huge amounts of polyunsaturated fatty acids, which from medical research is known to reduce heart disease.

开阔的海洋覆盖了地球表面的66%，初级生产者主要是非常丰富的微小球状生物。 在任何一个瞬间，这些细胞都是如此之多，如果它们被排列成一个标准的1 x 12板的形状，这个木板将从地球延伸到月球。 此外，这些细胞大约每天分裂一次，从而每天产生一个新的木板。 与森林不同，分裂细胞在树上积累了100年或更长时间，这些海洋中的微小植物很快就被吃掉了。 也就是说，植物营养素直接或间接地喂养鱼、虾、鲸等，所以这种神奇的“登月板”每天都在生产和食用。 因此，海洋沃茨看起来是透明的，没有森林般的生物量积累。 在这些微生物中，真核藻类是一个重要的组成部分。 然而，它们具有非常简单的形态，几乎不可能使用光学或电子显微镜进行识别。 虽然外观非常相似（小球形细胞），但从DNA研究来看，这些生物体显然代表了几个非常不同的进化群体。 直到最近才变得明显，需要涉及基因序列分析的分子研究来了解这种生物多样性。 培养物收藏，特别是比奇洛实验室的普罗瓦索里-吉拉德国家海洋浮游植物培养中心（CCMP），拥有来自大西洋，太平洋和印度洋蓝水地区的许多未识别的微小球形海洋藻类菌株。 在Robert Andersen博士的这项研究中，将对这些培养物和其他样本进行检查，以评估海洋生物多样性。 拟议的研究将利用核核糖体基因序列来识别和分类这些不同的生物体。 将使用额外的基因序列（例如，光合酶的基因）来研究隐藏物种复合体。将比较不同海洋以及同一海洋不同区域的物种组成。 目前还不清楚大西洋、太平洋和印度洋是否有类似或不同种类的这些丰富的微小真核球藻。 这项研究的结果将有助于我们了解海洋生态系统及其生产力。 此外，初步研究表明，其中一些微小的藻类产生的化合物对人类健康有益。 例如，新发现的海洋pinguiophytes产生大量的多不饱和脂肪酸，从医学研究中已知可以减少心脏病。