Jaeger, Daniel; Winkler, Anika; Mussgnug, Jan H.; Kalinowski, Jörn; Goesmann, Alexander; Kruse, Olaf: Time-resolved transcriptome analysis and lipid pathway reconstruction of the oleaginous green microalga Monoraphidium neglectum reveal a model for triacylglycerol [...]. In: Biotechnology for Biofuels. Jg.10 H. 1. 2017
Inhalt
- Overview of experiments
- Characterization of the cellular response of M. neglectum to nitrogen starvation to define the timing of starch, TAG, and total lipid accumulation
- Design of the transcriptome experiment and data evaluation
- Transcriptome reconstruction and quantification
- Effect of N resupply on gene expression of selected examples
- Global transcriptional responses in the three different stages of N availability
- Reconstruction of pathway maps and the glycerolipid metabolism of M. neglectum
- Transcriptional regulation of the glycerolipid metabolism of M. neglectum during the two stages of nitrogen starvation and the stage of nitrogen resupply
- Transcriptional regulation of the committed step of TAG synthesis
- Clustering of transcripts annotated as lipases reveals candidates likely involved in TAG accumulation and TAG degradation
- Reconstruction and prediction of compartmentalization of the central carbon metabolism of M. neglectum
- Differentially regulated genes of the central carbon metabolism during the three stages of N availability
- Transcriptional regulation of starch metabolism
- Discussion
- Global characterization of the three stages of N availability on the level of the transcriptome by GO term enrichment analysis
- Putative glycerolipid metabolism of M. neglectum
- The transcriptional regulation of the glycerolipid metabolism reveals several endogenous factors for TAG and total lipid hyperaccumulation
- Transcriptional regulation of the acylation of DAG, the committed step of TAG synthesis
- Sources of acetyl-CoA for FA synthesis in the l−N stage
- Transcriptional regulation of two enzymatic steps in the l−N stage of the central carbon metabolism might result in a re-routing that fuels into fatty acid synthesis
- Transcriptional regulation of glycerol-3-phosphate supply for TAG biosynthesis
- Transcriptional regulation of malic enzyme in M. neglectum suggests that this reaction likely does not have a central role in lipid hyperaccumulation in the l−N stage
- Enolase and C3 carbon transporters are subjected to differential transcriptional regulation in response to alternating nitrogen availability
- Thylakoid membrane lipid synthesis is likely stimulated on two different levels during the N resupply treatment
- The restoration of photosynthetic efficiency upon N resupply involves several steps with different timings
- Metabolic engineering strategies to optimize TAG production in M. neglectum
- Conclusions
- Methods
- Cultivation conditions
- Lipid extractions and chromatography
- Isolation of total RNA and DNase digest
- Starch determination
- Preparation of cDNA libraries and Illumina sequencing
- Read mapping and transcript quantification
- Functional annotation of the transcriptome
- Determination of gene sets and their GO term enrichment analysis
- Pathway reconstruction
- Identification of putative lipases and clustering of their transcriptional profiles
- Authors’ contributions
- References