サルガソ海の細菌プランクトンの遺伝的多様性

S J Giovannoni¹, T B Britschgi, C L Moyer

¹Department of Microbiology, Oregon State University, Corvallis 97331.

Nature

|May 3, 1990

まとめ

海洋細菌プランクトン群は多様で,サルガソ海で発見されたSAR11のような新しい微生物群がある. 遺伝子解析は,予期せぬ系統を明らかにし,微生物生態系に関する以前の理解に挑戦しています.

科学分野:

マリン・マイクロバイオロジー
分子生態学分子生態学
バイオジオケミストリーバイオジオケミストリー

背景:

バクテリオプランクトンは海の生地化学的サイクルを駆動するが,その種の構成と遺伝的多様性は未だに十分に理解されていない.
伝統的な微生物培養方法は,支配的な海洋細菌プランクトン集団の特徴付けには不十分であり,多様性推定の不一致につながる.

研究の目的:

16SリボソームRNA (rRNA) 遺伝子配列を用いて,サルガソ海の細菌プランクトン群を系統遺伝学的に分析する.
新しい微生物の系統を特定し,海洋細菌プランクトン集団内の遺伝的多様性を評価する.

主な方法:

エウバクテリアの16S rRNA遺伝子クローンライブラリの系統遺伝分析.
ポリメラーゼ連鎖反応 (PCR) を使用したサルガソ海のピコプランクトンから16SrRNA遺伝子の増幅.

主要な成果:

オリゴトロフなバクテリアプランクトンの重要な構成要素として,新しい微生物群であるSAR11クラスタの特定.
酸素性フォトトロフ (シアノバクテリア,プロクロロファイト,クロロプラスト) に関連する第二の系統群の観察.
観察されたrRNA遺伝子と,同様の環境から培った海洋サイアノバクテリアの間のマッチングの欠如は,培養バイアスを強調します.

結論:

SAR11クラスターは,これまで認識されていない海洋細菌プランクトンの主要な構成要素を表しています.
観察された遺伝的多様性は,海洋細菌プランクトンコミュニティが独立した系統の複雑なコンソーシアムであることを示唆しています.
現在の栽培技術は,海洋微生物生態系における支配的な種を正確に表現できない可能性があります.

さらに関連する動画

08:09

An Aquatic Microbial Metaproteomics Workflow: From Cells to Tryptic Peptides Suitable for Tandem Mass Spectrometry-based Analysis

Published on: September 15, 2015

08:03

Heuristic Mining of Hierarchical Genotypes and Accessory Genome Loci in Bacterial Populations

Published on: December 7, 2021

関連する概念動画

00:46

Genomic DNA in Prokaryotes

The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the nucleoid. The chromosome is tightly wound, or supercoiled, for efficient storage. Prokaryotes also contain other circular pieces of DNA called plasmids. These plasmids are smaller than the chromosome and often carry genes that confer adaptive functions, such as antibiotic resistance.
Genomic Diversity in Bacteria
Although bacterial genomes are much...

01:29

Modern Molecular Taxonomy

Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately...

01:15

Diversity of Protists I

Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...

01:27

Diversity of Protists III

Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...

01:30

Marine Microbial Ecology

Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...

01:18

Deep Sea Microbial Ecology

The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...

関連する実験動画