Gene Expression Nebulas
基于标准化流程分析的转录图谱综合数据库

Gene Expression Nebulas

多物种转录图谱整合数据库

PRJNA378177: Understanding lipid metabolism in high-lipid-producing Chlorella vulgaris mutants at the genome-wide level

来源: NCBI / GSE95708
提交时间: Mar 06, 2017
释放时间: Nov 13 2017
最后更新时间: May 15 2019

概要: In this study, physical and chemical mutagenesis methods were applied to enhance lipid productivity in Chlorella vulgaris. Then, de novo RNA-seq was performed to observe lipid metabolism changes at the genome-wide level. Characterization of two mutants, UV-715 and EMS-25, showed marked increases in lipid contents, i.e., 42% and 45%, respectively. In addition, the biomass productivity of the UV-715 cells was 9% higher than that of wild-type cells. Furthermore, gas chromatography-mass spectrophotometry analysis showed that both mutants have higher fatty acid methyl ester (FAME) contents than wild-type cells. To understand the effect of mutations that caused yield changes in UV-715 and EMS-25 cells at a genome-wide level, we carried out de novo RNA-seq. As expected, the transcriptional levels of the lipid biosynthesis genes were up-regulated, while the transcriptional levels of genes involved in lipid catabolism were down-regulated. Surprisingly, the transcriptional levels of the genes involved in nitrate assimilation and detoxification of reactive oxygen species (ROS) were significantly increased in the mutants. The genome-wide analysis results highlight the importance of nitrate metabolism and detoxification of ROS for high biomass and lipid productivity.

项目整体设计: mRNA profiles of wild type and mutant (UV-715 and EMS-25) Chlorella vulgaris SAG 211-12 cells were generated at stationary phase cell culture by deep sequencing, in two biological replicates, using Illumina MiSeq platform.

GEN 数据集:
GEND000640
测序方法:
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方案
生长方案: Chlorella vulgaris (SAG 211-12) was obtained from the collection of algal cultures at the University of Göttingen, Germany. The inoculum was grown in Bold’s Basal medium consisting of (per liter): 0.25 g NaNO3, 0.075 g MgSO4.7H2O, 0.075 g K2HPO4, 0.175 g KH2PO4, 0.025 g NaCl, 0.025 g CaCl2.2H2O, 8.82 mg ZnSO4.7H2O, 0.44 mg MnCl2.4H2O, 0.71 mg MoO3, 1.57 mg CuSO4.5H2O, 0.49 mg CoCl2.6H2O, 11.42 mg H3BO3, 50 mg EDTA, 31 mg KOH, 4.98 mg feSO4.7H2O. Cultures were maintained at 25◦C under continuous illumination by four fluorescent lamps
处理方案: 250 µl culture of C. vulgaris with the cell count of 4×10e8 cells/ml was spread on solid Bold’s basal media and then exposed to UV irradiation (254 nm) with an intensity of 2.9 ×10-2 W/cm2 for 0.5 to 10 minutes at a distance of 15 cm. UVX Digital Radiometer (UVP, USA) was used to measure the UV-light intensity. The UV-irradiated plates were kept in dark for 24 h to prevent light-induced repair. The plates were then maintained under normal light for 2 weeks. Single colonies appearing on plates were selected and transferred individually into 2 ml Bold’s basal medium. After 10 days of culturing, the cell densities were determined by measuring OD at 680 nm.
提取方案: Total RNA was extracted from 14-days old stationary phase reached (OD680=5) 5 ml cell culture using TRIzol reagent (Invitrogen, USA) according to the manufacturer’s instructions. Briefly, after quality and quantity measurement using 2100 BioAnalyzer (Agilent, USA), it was treated with RNase-free DNase I (Thermo Scientific, USA) at a concentration of 1 U/µg to remove residual genomic DNA. Then, RNA-seq library preparation was performed using TruSeq mRNA Sample Preparation Kit (Illumina, USA) according to the manufacturer’s instructions. mRNAs were purified from the 1 µg of total RNA using oligo (dT) magnetic beads and fragmented using fragmentation buffer. Afterthat, the cleaved short RNA fragments were used for first-strand cDNA synthesis using first strand synthesis mix, and the second strand was synthesized using second strand marking master mix. The double strand cDNAs were purified with AMPure XP beads (Beckman Coulter, USA) and eluted with resuspension buffer followed by 3’end adenine nucleotide addition. Finally, sequencing adaptors were ligated to the fragments and cDNA fragments were enriched by PCR amplification.
建库方案: Enriched cDNA libraries were used for cluster generation and sequencing. 75x2 paired-end sequencing of three cDNA libraries (WT, UV-715 and EMS-25) with two biological replicates were performed using the Illumina MiSeq sequencing platform (Illumina, USA). All sequence data are PE 2x75 bp. Image processing, base calling, and quality calue calculation were performed by the Illumina data processing pipeline (v1.5). High quality reads were saved in FASTQ format.
测序信息
分子类型: polyA(+) RNA
库的片段类型: PAIRED
库的链类型: -; Reverse
测序平台: ILLUMINA
测序仪型号: Illumina MiSeq
链特异性: Unspecific; Specific
样本
基本信息:
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数据来源 GEN样本编号 GEN数据集编号 系列编号 项目编号 样本编号 样本名称 生物样本编号 样本访问号 实验访问号 释放时间 提交时间 最后更新时间 物种 种族 族裔 年龄 年龄单位 性别 来源名称 组织 细胞类型 细胞亚型 细胞系 疾病 疾病状态 发育阶段 突变/变异 表型 Condition Detail 生长方案 处理方案 提取方案 建库方案 分子类型 库的片段类型 链特异性 库的链类型 加标(Spike-In) 测序方法 测序平台 测序仪型号 细胞数 测序片段数 碱基数 平均测序片段长度_1 平均测序片段长度_2 唯一比对率 多重比对率 覆盖度