气候变化领域集成服务门户(CCPortal): Phylogenetic diversity in freshwater-dwelling Isochrysidales haptophytes with implications for alkenone production

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DOI	10.1111/gbi.12330
	Phylogenetic diversity in freshwater-dwelling Isochrysidales haptophytes with implications for alkenone production
	Richter N.; Longo W.M.; George S.; Shipunova A.; Huang Y.; Amaral-Zettler L.
发表日期	2019
ISSN	14724677
起始页码	272
结束页码	280
卷号	17 期号:3
英文摘要	Members of the order Isochrysidales are unique among haptophyte lineages in being the exclusive producers of alkenones, long-chain ketones that are commonly used for paleotemperature reconstructions. Alkenone-producing haptophytes are divided into three major groups based largely on molecular ecological data: Group I is found in freshwater lakes, Group II commonly occurs in brackish and coastal marine environments, and Group III consists of open ocean species. Each group has distinct alkenone distributions; however, only Groups II and III Isochrysidales currently have cultured representatives. The uncultured Group I Isochrysidales are distinguished geochemically by the presence of tri-unsaturated alkenone isomers (C37:3b Me, C38:3b Et, C38:3b Me, C39:3b Et) present in water column and sediment samples, yet their genetic diversity, morphology, and environmental controls are largely unknown. Using small-subunit (SSU) ribosomal RNA (rRNA) marker gene amplicon high-throughput sequencing of environmental water column and sediment samples, we show that Group I is monophyletic with high phylogenetic diversity and contains a well-supported clade separating the previously described “EV” clade from the “Greenland” clade. We infer the first partial large-subunit (LSU) rRNA gene Group I sequence phylogeny, which uncovered additional well-supported clades embedded within Group I. Relative to Group II, Group I revealed higher levels of genetic diversity despite conservation of alkenone signatures and a closer evolutionary relationship with Group III. In Group I, the presence of the tri-unsaturated alkenone isomers appears to be conserved, which is not the case for Group II. This suggests differing environmental influences on Group I and II and perhaps uncovers evolutionary constraints on alkenone biosynthesis. © 2019 The Authors Geobiology Published by John Wiley & Sons Ltd
关键词	alkenone eukaryote genetic variation lacustrine environment marine environment open ocean paleotemperature phylogenetics species diversity Arctic Greenland Haptophyceae Isochrysidales ketone ribosome DNA Alaska chemistry classification evolution genetics Germany Haptophyta Iceland lake metabolism microbiology phylogeny sequence analysis Alaska Biological Evolution DNA, Ribosomal Germany Haptophyta Iceland Ketones Lakes Phylogeny Sequence Analysis, RNA
语种	英语
来源机构	Geobiology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/133232
推荐引用方式 GB/T 7714	Richter N.,Longo W.M.,George S.,et al. Phylogenetic diversity in freshwater-dwelling Isochrysidales haptophytes with implications for alkenone production[J]. Geobiology,2019,17(3).
APA	Richter N.,Longo W.M.,George S.,Shipunova A.,Huang Y.,&Amaral-Zettler L..(2019).Phylogenetic diversity in freshwater-dwelling Isochrysidales haptophytes with implications for alkenone production.,17(3).
MLA	Richter N.,et al."Phylogenetic diversity in freshwater-dwelling Isochrysidales haptophytes with implications for alkenone production".17.3(2019).