NF?B activity and target gene expression in the rat brain after one and two exposures to ionizing radiation

AbstractReal-time reverse transcription PCR (qPCR) normalized to an internal reference gene (RG), is a frequently used method for quantifying gene expression changes in neuroscience. Although RG expression is assumed to be constantly independent of physiological or experimental conditions, several studies have shown that commonly used RGs are not expressed stably. The use of unstable RGs has a profound effect on the conclusions drawn from studies on gene expression, and almost universally results in spurious estimation of target gene expression. Approaches aimed at selecting and validating RGs often make use of different statistical methods, which may lead to conflicting results. The present study evaluates the expression of 5 candidate RGs (Actb, Pgk1, Sdha, Gapdh, Rnu6b) as a function of hypoxia exposure and hypothermic treatment in the neonatal rat cerebral cortex –in order to identify RGs that are stably expressed under these experimental conditions– and compares several statistical approaches that have been proposed to validate RGs. In doing so, we first analyzed the RG ranking stability proposed by several widely used statistical methods and related tools, i.e. the Coefficient of Variation (CV) analysis, GeNorm, NormFinder, BestKeeper, and the ΔCt method. Subsequently, we compared RG expression patterns between the various experimental groups. We found that these statistical methods, next to producing different rankings per se, all ranked RGs displaying significant differences in expression levels between groups as the most stable RG. As a consequence, when assessing the impact of RG selection on target gene expression quantification, substantial differences in target gene expression profiles were observed. As such, by assessing mRNA expression profiles within the neonatal rat brain cortex in hypoxia and hypothermia as a showcase, this study underlines the importance of further validating RGs for each new experimental paradigm considering the limitations of each selection method.

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2049-P: The Chd4 Helicase of the Nucleosome Remodeling and Deacetylase Complex Modulates Pdx1 Target Gene Expression In Vitro

Diabetes ◽

10.2337/db20-2049-p ◽

2020 ◽

Vol 69 (Supplement 1) ◽

pp. 2049-P

Author(s):

REBECCA K. DAVIDSON ◽

NOLAN CASEY ◽

JASON SPAETH

Keyword(s):

Gene Expression ◽

Target Gene ◽

Nucleosome Remodeling ◽

Target Gene Expression

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On the way toward regulatable expression systems in acetic acid bacteria: target gene expression and use cases

Applied Microbiology and Biotechnology ◽

10.1007/s00253-021-11269-z ◽

2021 ◽

Author(s):

Philipp Moritz Fricke ◽

Angelika Klemm ◽

Michael Bott ◽

Tino Polen

Keyword(s):

Gene Expression ◽

Acetic Acid ◽

Literature Search ◽

Target Gene ◽

Target Genes ◽

Recombinant Dna ◽

Acetic Acid Bacteria ◽

Homoserine Lactone ◽

Expression Systems ◽

Target Gene Expression

Abstract Acetic acid bacteria (AAB) are valuable biocatalysts for which there is growing interest in understanding their basics including physiology and biochemistry. This is accompanied by growing demands for metabolic engineering of AAB to take advantage of their properties and to improve their biomanufacturing efficiencies. Controlled expression of target genes is key to fundamental and applied microbiological research. In order to get an overview of expression systems and their applications in AAB, we carried out a comprehensive literature search using the Web of Science Core Collection database. The Acetobacteraceae family currently comprises 49 genera. We found overall 6097 publications related to one or more AAB genera since 1973, when the first successful recombinant DNA experiments in Escherichia coli have been published. The use of plasmids in AAB began in 1985 and till today was reported for only nine out of the 49 AAB genera currently described. We found at least five major expression plasmid lineages and a multitude of further expression plasmids, almost all enabling only constitutive target gene expression. Only recently, two regulatable expression systems became available for AAB, an N-acyl homoserine lactone (AHL)-inducible system for Komagataeibacter rhaeticus and an l-arabinose-inducible system for Gluconobacter oxydans. Thus, after 35 years of constitutive target gene expression in AAB, we now have the first regulatable expression systems for AAB in hand and further regulatable expression systems for AAB can be expected. Key points • Literature search revealed developments and usage of expression systems in AAB. • Only recently 2 regulatable plasmid systems became available for only 2 AAB genera. • Further regulatable expression systems for AAB are in sight.

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