scholarly journals New experimental and computational approaches to the analysis of gene expression.

1998 ◽  
Vol 45 (4) ◽  
pp. 929-934 ◽  
Author(s):  
J A Rafalski ◽  
M Hanafey ◽  
G H Miao ◽  
A Ching ◽  
J M Lee ◽  
...  
Keyword(s):  
Gene Expression ◽  
Data Base ◽  
Developmental Stages ◽  
Expressed Sequence Tag ◽  
Expression Profiles ◽  
Soybean Seed ◽  
Fluorescent Labeling ◽  
Cdna Libraries ◽  
Northern Analysis ◽  
Expression Levels

Public and private EST (Expressed Sequence Tag) programs provide access to a large number of ESTs from a number of plant species, including Arabidopsis, corn, soybean, rice, wheat. In addition to the homology of each EST to genes in GenBank, information about homology to all other ESTs in the data base can be obtained. To estimate expression levels of genes represented in the DuPont EST data base we count the number of times each gene has been seen in different cDNA libraries, from different tissues, developmental stages or induction conditions. This quantitation of message levels is quite accurate for highly expressed messages and, unlike conventional Northern blots, allows comparison of expression levels between different genes. Lists of most highly expresses genes in different libraries can be compiled. Also, if EST data is available for cDNA libraries derived from different developmental stages, gene expression profiles across development can be assembled. We present an example of such a profile for soybean seed development. Gene expression data obtained from Electronic Northern analysis can be confirmed and extended beyond the realm of highly expressed genes by using high density DNA arrays. The ESTs identified as interesting can be arrayed on nylon or glass and probed with total labeled cDNA first strand from the tissue of interest. Two-color fluorescent labeling allows accurate mRNA ratio measurements. We are currently using the DNA array technology to study chemical induction of gene expression and the biosynthesis of oil, carbohydrate and protein in developing seeds.

scholarly journals EST analysis of cDNA libraries from the entomopathogenic fungus Beauveria (Cordyceps) bassiana. I. Evidence for stage-specific gene expression in aerial conidia, in vitro blastospores and submerged conidia

Microbiology ◽  
2006 ◽  
Vol 152 (9) ◽  
pp. 2843-2854 ◽  
Author(s):  
Eun-Min Cho ◽  
Li Liu ◽  
William Farmerie ◽  
Nemat O. Keyhani
Keyword(s):  
Gene Expression ◽  
Entomopathogenic Fungus ◽  
Expressed Sequence Tag ◽  
Biological Control Agent ◽  
Expression Profiles ◽  
Cdna Libraries ◽  
Specific Gene ◽  
Cell Type ◽  
Aerial Conidia

The entomopathogenic fungus Beauveria (Cordyceps) bassiana holds much promise as a pest biological control agent. B. bassiana produces at least three in vitro single cell infectious propagules, including aerial conidia, vegetative cells termed blastospores and submerged conidia, that display different morphological, biochemical and virulence properties. Populations of aerial conidia, blastospores and submerged conidia were produced on agar plates, rich liquid broth cultures and under conditions of nutrient limitation in submerged cultures, respectively. cDNA libraries were generated from mRNA isolated from each B. bassiana cell type and ∼2500 5′ end sequences were determined from each library. Sequences derived from aerial conidia clustered into 284 contigs and 963 singlets, with those derived from blastospores and submerged conidia forming 327 contigs with 788 singlets, and 303 contigs and 1079 contigs, respectively. Almost half (40–45 %) of the sequences in each library displayed either no significant similarity (e value >10−4) or similarity to hypothetical proteins found in the NCBI database. The expressed sequence tag dataset also included sequences representing a significant portion of proteins in cellular metabolism, information storage and processing, transport and cell processes, including cell division and posttranslational modifications. Transcripts encoding a diverse array of pathogenicity-related genes, including proteases, lipases, esterases, phosphatases and enzymes producing toxic secondary metabolites, were also identified. Comparative analysis between the libraries identified 2416 unique sequences, of which 20–30 % were unique to each library, and only ∼6 % of the sequences were shared between all three libraries. The unique and divergent representation of the B. bassiana transcriptome in the cDNA libraries from each cell type suggests robust differential gene expression profiles in response to environmental conditions.

scholarly journals Use of a large-scale Triticeae expressed sequence tag resource to reveal gene expression profiles in hexaploid wheat (Triticum aestivum L.)

Genome ◽  
2006 ◽  
Vol 49 (5) ◽  
pp. 531-544 ◽  
Author(s):  
S Chao ◽  
G R Lazo ◽  
F You ◽  
C C Crossman ◽  
D D Hummel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Triticum Aestivum ◽  
Expressed Sequence Tag ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Tetraploid Wheat ◽  
Gene Expression Profiles ◽  
Triticum Aestivum L ◽  
Cdna Libraries ◽  
Expressed Sequence

The US Wheat Genome Project, funded by the National Science Foundation, developed the first large public Triticeae expressed sequence tag (EST) resource. Altogether, 116 272 ESTs were produced, comprising 100 674 5′ ESTs and 15 598 3′ ESTs. These ESTs were derived from 42 cDNA libraries, which were created from hexaploid bread wheat (Triticum aestivum L.) and its close relatives, including diploid wheat (T. monococcum L. and Aegilops speltoides L.), tetraploid wheat (T. turgidum L.), and rye (Secale cereale L.), using tissues collected from various stages of plant growth and development and under diverse regimes of abiotic and biotic stress treatments. ESTs were assembled into 18 876 contigs and 23 034 singletons, or 41 910 wheat unigenes. Over 90% of the contigs contained fewer than 10 EST members, implying that the ESTs represented a diverse selection of genes and that genes expressed at low and moderate to high levels were well sampled. Statistical methods were used to study the correlation of gene expression patterns, based on the ESTs clustered in the1536 contigs that contained at least 10 5′ EST members and thus representing the most abundant genes expressed in wheat. Analysis further identified genes in wheat that were significantly upregulated (p < 0.05) in tissues under various abiotic stresses when compared with control tissues. Though the function annotation cannot be assigned for many of these genes, it is likely that they play a role associated with the stress response. This study predicted the possible functionality for 4% of total wheat unigenes, which leaves the remaining 96% with their functional roles and expression patterns largely unknown. Nonetheless, the EST data generated in this project provide a diverse and rich source for gene discovery in wheat.Key words: Expressed sequence tags, ESTs, gene expression profiles, wheat, Triticeae.

scholarly journals Genome-Wide Identification of Soybean ABC Transporters Relate to Aluminum Toxicity

2021 ◽  
Vol 22 (12) ◽  
pp. 6556
Author(s):  
Junjun Huang ◽  
Xiaoyu Li ◽  
Xin Chen ◽  
Yaru Guo ◽  
Weihong Liang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Abc Transporters ◽  
Developmental Stages ◽  
Aluminum Toxicity ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Purifying Selection ◽  
Biotic Stresses ◽  
Genome Wide ◽  
New Germplasm

ATP-binding cassette (ABC) transporter proteins are a gene super-family in plants and play vital roles in growth, development, and response to abiotic and biotic stresses. The ABC transporters have been identified in crop plants such as rice and buckwheat, but little is known about them in soybean. Soybean is an important oil crop and is one of the five major crops in the world. In this study, 255 ABC genes that putatively encode ABC transporters were identified from soybean through bioinformatics and then categorized into eight subfamilies, including 7 ABCAs, 52 ABCBs, 48 ABCCs, 5 ABCDs, 1 ABCEs, 10 ABCFs, 111 ABCGs, and 21 ABCIs. Their phylogenetic relationships, gene structure, and gene expression profiles were characterized. Segmental duplication was the main reason for the expansion of the GmABC genes. Ka/Ks analysis suggested that intense purifying selection was accompanied by the evolution of GmABC genes. The genome-wide collinearity of soybean with other species showed that GmABCs were relatively conserved and that collinear ABCs between species may have originated from the same ancestor. Gene expression analysis of GmABCs revealed the distinct expression pattern in different tissues and diverse developmental stages. The candidate genes GmABCB23, GmABCB25, GmABCB48, GmABCB52, GmABCI1, GmABCI5, and GmABCI13 were responsive to Al toxicity. This work on the GmABC gene family provides useful information for future studies on ABC transporters in soybean and potential targets for the cultivation of new germplasm resources of aluminum-tolerant soybean.

scholarly journals Analysis of Expressed Sequence Tag Data and Gene Expression Profiles Involved in Conidial Germination of Fusarium oxysporum

2006 ◽  
Vol 72 (2) ◽  
pp. 1667-1671 ◽  
Author(s):  
Ye Deng ◽  
Haitao Dong ◽  
Qingchao Jin ◽  
Cheng'en Dai ◽  
Yongqi Fang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Fusarium Oxysporum ◽  
Cdna Library ◽  
Expressed Sequence Tag ◽  
Expression Profiles ◽  
Cdna Array ◽  
Gene Expression Profiles ◽  
Conidial Germination ◽  
Expressed Sequence

ABSTRACT We obtained 3,372 tentative unique transcripts (TUTs) from a cDNA library of Fusarium oxysporum. A cDNA array with 3,158 TUTs was produced to analyze gene expression profiles in conidial germination. It seems that ras and other signaling genes, e.g., ccg, cooperatively initiate conidial germination in Fusarium by increasing protein synthesis.

scholarly journals Exploration and validation of a novel prognostic signature based on comprehensive bioinformatics analysis in hepatocellular carcinoma

2020 ◽  
Vol 40 (11) ◽  
Author(s):  
Xiaofei Wang ◽  
Jie Qiao ◽  
Rongqi Wang
Keyword(s):  
Gene Expression ◽  
Hepatocellular Carcinoma ◽  
Overall Survival ◽  
Risk Score ◽  
Expression Profiles ◽  
Univariate Analysis ◽  
Cancer Genome ◽  
The Cancer Genome Atlas ◽  
Good Prediction ◽  
Expression Levels

Abstract The present study aimed to construct a novel signature for indicating the prognostic outcomes of hepatocellular carcinoma (HCC). Gene expression profiles were downloaded from Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) databases. The prognosis-related genes with differential expression were identified with weighted gene co-expression network analysis (WGCNA), univariate analysis, the least absolute shrinkage and selection operator (LASSO). With the stepwise regression analysis, a risk score was constructed based on the expression levels of five genes: Risk score = (−0.7736* CCNB2) + (1.0083* DYNC1LI1) + (−0.6755* KIF11) + (0.9588* SPC25) + (1.5237* KIF18A), which can be applied as a signature for predicting the prognosis of HCC patients. The prediction capacity of the risk score for overall survival was validated with both TCGA and ICGC cohorts. The 1-, 3- and 5-year ROC curves were plotted, in which the AUC was 0.842, 0.726 and 0.699 in TCGA cohort and 0.734, 0.691 and 0.700 in ICGC cohort, respectively. Moreover, the expression levels of the five genes were determined in clinical tumor and normal specimens with immunohistochemistry. The novel signature has exhibited good prediction efficacy for the overall survival of HCC patients.

scholarly journals Transcriptomic profiles of non-embryogenic and embryogenic callus cells in a highly regenerative Upland Cotton line (Gossypium hirsutum L.)

2020 ◽  
Author(s):  
Li Wen ◽  
Wei Li ◽  
Stephen Parris ◽  
Matthew West ◽  
John Lawson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Somatic Embryogenesis ◽  
Transcription Factors ◽  
Gossypium Hirsutum ◽  
Embryogenic Callus ◽  
Developmental Stages ◽  
Baby Boom ◽  
Expression Profiles ◽  
Enrichment Analysis ◽  
Study Gene Expression

Abstract • Background • Genotype independent transformation and whole plant regeneration through somatic embryogenesis relies heavily on the intrinsic ability of a genotype to regenerate. • Results • In this study, gene expression profiles of a highly regenerable Gossypium hirsutum L. cultivar, Jin668, were analyzed at two critical developmental stages during somatic embryogenesis, non-embryogenic callus (NEC) cells and embryogenic callus (EC) cells. The rate of EC formation in Jin668 is 96%. Differential gene expression analysis revealed a total of 5,333 differentially expressed genes (DEG) with 2,534 upregulated and 2,799 downregulated in EC. A total of 144 genes were unique to NEC cells and 174 genes unique to EC. Clustering and enrichment analysis identified genes upregulated in EC that function as transcription factors/DNA binding, phytohormone response, oxidative reduction, and regulators of transcription; while genes categorized in methylation pathways were downregulated. Four key transcription factors were identified based on their sharp upregulation in EC tissue; LEAFY COTYLEDON 1 (LEC1), BABY BOOM (BBM), FUSCA (FUS3) and AGAMOUS-LIKE15 with distinguishable subgenome expression bias. • Conclusions • This comparative analysis of NEC and EC transcriptomes gives new insights into the genetic underpinnings of somatic embryogenesis in cotton.

scholarly journals DNA Methylation and RNA-Sequencing Analysis Show Epigenetic Function During Grain Filling in Foxtail Millet (Setaria italica L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Tao Wang ◽  
Quanwei Lu ◽  
Hui Song ◽  
Nan Hu ◽  
Yangyang Wei ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Potential Function ◽  
Developmental Stages ◽  
Expression Profiles ◽  
Dynamic Change ◽  
Foxtail Millet ◽  
Grain Filling ◽  
Sequencing Analysis ◽  
Grain Development

Grain filling is a crucial process for crop yield and quality. Certain studies already gained insight into the molecular mechanism of grain filling. However, it is unclear whether epigenetic modifications are associated with grain filling in foxtail millet. Global DNA methylation and transcriptome analysis were conducted in foxtail millet spikelets during different stages to interpret the epigenetic effects of the grain filling process. The study employed the whole-genome bisulfite deep sequencing and advanced bioinformatics to sequence and identify all DNA methylation during foxtail millet grain filling; the DNA methylation-mediated gene expression profiles and their involved gene network and biological pathway were systematically studied. One context of DNA methylation, namely, CHH methylation, was accounted for the largest percentage, and it was gradually increased during grain filling. Among all developmental stages, the methylation levels were lowest at T2, followed by T4, which mainly occurred in CHG. The distribution of differentially methylated regions (DMR) was varied in the different genetic regions for three contexts. In addition, gene expression was negatively associated with DNA methylation. Evaluation of the interconnection of the DNA methylome and transcriptome identified some stage-specific differentially expressed genes associated with the DMR at different stages compared with the T1 developmental stage, indicating the potential function of epigenetics on the expression regulation of genes related to the specific pathway at different stages of grain development. The results demonstrated that the dynamic change of DNA methylation plays a crucial function in gene regulation, revealing the potential function of epigenetics in grain development in foxtail millet.

scholarly journals Quantitative Gene Expression Profiles in Real Time From Expressed Sequence Tag Databases

2010 ◽  
Vol 14 (6) ◽  
pp. 321-336 ◽  
Author(s):  
VINCENT A. FUNARI ◽  
KONSTANTIN VOEVODSKI ◽  
DIMITRY LEYFER ◽  
LAURA YERKES ◽  
DONALD CRAMER ◽  
...  
Keyword(s):  
Gene Expression ◽  
Real Time ◽  
Expressed Sequence Tag ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Quantitative Gene Expression ◽  
Expressed Sequence

Mapping cis-acting regulatory variation in recombinant congenic strains

2006 ◽  
Vol 25 (2) ◽  
pp. 294-302 ◽  
Author(s):  
Peter D. Lee ◽  
Bing Ge ◽  
Celia M. T. Greenwood ◽  
Donna Sinnett ◽  
Yannick Fortin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Fisher Exact Test ◽  
Donor Strain ◽  
Exact Test ◽  
Expression Levels ◽  
Cis Acting ◽  
Congenic Strains ◽  
Recombinant Congenic Strains ◽  
Genetic Context

We present an integrated approach for the enriched detection of genes subject to cis-acting variation in the mouse genome. Gene expression profiling was performed with lung tissue from a panel of recombinant congenic strains (RCS) derived from A/J and C57BL/6J inbred mouse strains. A multiple-regression model measuring the association between gene expression level, donor strain of origin (DSO), and predominant strain background identified over 1,500 genes ( P < 0.05) whose expression profiles differed according to the DSO. This model also identified over 1,200 genes whose expression showed dependence on background ( P < 0.05), indicating the influence of background genetic context on transcription levels. Sequences obtained from 1-kb segments of 3′-untranslated regions identified single nucleotide polymorphisms in 64% of genes whose expression levels correlated with DSO status, compared with 29% of genes that displayed no association ( P < 0.01, Fisher exact test). Allelic imbalance was identified in 50% of genes positive for expression-DSO association, compared with 22% of negative genes ( P < 0.05, Fisher exact test). Together, these results demonstrate the utility of RCS mice for identifying the roles of proximal genetic determinants and background genetic context in determining gene expression levels. We propose the use of this integrated experimental approach in multiple tissues from this and other RCS panels as a means for genome-wide cataloging of genetic regulatory mechanisms in laboratory strains of mice.

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