Cell-specific gene expression in Anabaena variabilis grown phototrophically, mixotrophically, and heterotrophically

BMC Genomics

Research Article

Claire Vieille¹  Jeong-Jin Park²  Sigal Lechno-Yossef³  Coleman Peter Wolk⁴ 

[1] Great Lakes Bioenergy Research Center, Michigan State University, 48824, East Lansing, MI, USA;Department of Microbiology & Molecular Genetics, Michigan State University, 48824, East Lansing, MI, USA;Department of Biochemistry & Molecular Biology, Michigan State University, 48824, East Lansing, MI, USA;Great Lakes Bioenergy Research Center, Michigan State University, 48824, East Lansing, MI, USA;Department of Microbiology & Molecular Genetics, Michigan State University, 48824, East Lansing, MI, USA;Institute of Biological Chemistry, Washington State University, 99164, Pullman, WA, USA;Great Lakes Bioenergy Research Center, Michigan State University, 48824, East Lansing, MI, USA;MSU-DOE Plant Research Laboratory, Michigan State University, 48824, East Lansing, MI, USA;Great Lakes Bioenergy Research Center, Michigan State University, 48824, East Lansing, MI, USA;MSU-DOE Plant Research Laboratory, Michigan State University, 48824, East Lansing, MI, USA;Department of Plant Biology, Michigan State University, 48824, East Lansing, MI, USA;

关键词: Anabaena variabilis;    Amino acid biosynthesis;    Vegetative cell;    Heterocyst;    Transcript levels;    Microarray;   

DOI  :  10.1186/1471-2164-14-759

 received in 2013-04-21, accepted in 2013-10-26,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundWhen the filamentous cyanobacterium Anabaena variabilis grows aerobically without combined nitrogen, some vegetative cells differentiate into N2-fixing heterocysts, while the other vegetative cells perform photosynthesis. Microarrays of sequences within protein-encoding genes were probed with RNA purified from extracts of vegetative cells, from isolated heterocysts, and from whole filaments to investigate transcript levels, and carbon and energy metabolism, in vegetative cells and heterocysts in phototrophic, mixotrophic, and heterotrophic cultures.ResultsHeterocysts represent only 5% to 10% of cells in the filaments. Accordingly, levels of specific transcripts in vegetative cells were with few exceptions very close to those in whole filaments and, also with few exceptions (e.g., nif1 transcripts), levels of specific transcripts in heterocysts had little effect on the overall level of those transcripts in filaments. In phototrophic, mixotrophic, and heterotrophic growth conditions, respectively, 845, 649, and 846 genes showed more than 2-fold difference (p < 0.01) in transcript levels between vegetative cells and heterocysts. Principal component analysis showed that the culture conditions tested affected transcript patterns strongly in vegetative cells but much less in heterocysts. Transcript levels of the genes involved in phycobilisome assembly, photosynthesis, and CO2 assimilation were high in vegetative cells in phototrophic conditions, and decreased when fructose was provided. Our results suggest that Gln, Glu, Ser, Gly, Cys, Thr, and Pro can be actively produced in heterocysts. Whether other protein amino acids are synthesized in heterocysts is unclear. Two possible components of a sucrose transporter were identified that were upregulated in heterocysts in two growth conditions. We consider it likely that genes with unknown function represent a larger fraction of total transcripts in heterocysts than in vegetative cells across growth conditions.ConclusionsThis study provides the first comparison of transcript levels in heterocysts and vegetative cells from heterocyst-bearing filaments of Anabaena. Although the data presented do not give a complete picture of metabolism in either type of cell, they provide a metabolic scaffold on which to build future analyses of cell-specific processes and of the interactions of the two types of cells.

【 授权许可】

Unknown   
© Park et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.