scholarly journals Evidence from oyster suggests an ancient role for Pdx in regulating insulin gene expression in animals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fei Xu ◽  
Ferdinand Marlétaz ◽  
Daria Gavriouchkina ◽  
Xiao Liu ◽  
Tatjana Sauka-Spengler ◽  
...  
Keyword(s):  
Gene Expression ◽  
Regulatory Element ◽  
Expression Patterns ◽  
Homeobox Gene ◽  
Gene Interaction ◽  
Binding Interaction ◽  
Upstream Regulatory Element ◽  
A Cell ◽  
Insulin Gene Expression ◽  
Cell Culture Assay

AbstractHox and ParaHox genes encode transcription factors with similar expression patterns in divergent animals. The Pdx (Xlox) homeobox gene, for example, is expressed in a sharp spatial domain in the endodermal cell layer of the gut in chordates, echinoderms, annelids and molluscs. The significance of comparable gene expression patterns is unclear because it is not known if downstream transcriptional targets are also conserved. Here, we report evidence indicating that a classic transcriptional target of Pdx1 in vertebrates, the insulin gene, is a likely direct target of Pdx in Pacific oyster adults. We show that one insulin-related gene, cgILP, is co-expressed with cgPdx in oyster digestive tissue. Transcriptomic comparison suggests that this tissue plays a similar role to the vertebrate pancreas. Using ATAC-seq and ChIP, we identify an upstream regulatory element of the cgILP gene which shows binding interaction with cgPdx protein in oyster hepatopancreas and demonstrate, using a cell culture assay, that the oyster Pdx can act as a transcriptional activator through this site, possibly in synergy with NeuroD. These data argue that a classic homeodomain-target gene interaction dates back to the origin of Bilateria.

scholarly journals An Alternative Platform for Protein Expression Using an Innate Whole Expression Module from Metagenomic DNA

2019 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Dae-Eun Cheong ◽  
So-Youn Park ◽  
Ho-Dong Lim ◽  
Geun-Joong Kim
Keyword(s):  
Gene Expression ◽  
Regulatory Element ◽  
Expression System ◽  
Expression Patterns ◽  
Gene Clusters ◽  
Single Element ◽  
Reading Frame ◽  
Cis Acting ◽  
Dna Libraries ◽  
Expression Module

Many integrated gene clusters beyond a single genetic element are commonly trapped as the result of promoter traps in (meta)genomic DNA libraries. Generally, a single element, which is mainly the promoter, is deduced from the resulting gene clusters and employed to construct a new expression vector. However, expression patterns of target proteins under the incorporated promoter are often inconsistent with those shown in clones harboring plasmids with gene clusters. These results suggest that the integrated set of gene clusters with diverse cis- and trans-acting elements is evolutionarily tuned as a complete set for gene expression, and is an expression module with all the components for the expression of a nested open reading frame (ORF). This possibility is further supported by truncation and/or serial deletion analysis of this module in which the expression of the nested ORF is highly fluctuated or reduced frequently, despite being supported by plentiful cis-acting elements in the spanning regions around the ORF such as the promoter, ribosome binding site (RBS), terminator, and 3′-/5′-UTRs for gene expression. Here, we examined whether an innate module with a naturally overexpressed gene could be considered as a scaffold for an expression system. For a proof-of-principle study, we mined a complete expression module with an innately overexpressed ORF in E. coli from a metagenomics DNA library, and incorporated it into a vector that had no regulatory element for expressing the insert. We obtained successful expression of several inserts such as MBP, GFPuv, β-glucosidase, and esterase using this simple construct without tuning and codon optimization of the target insert.

scholarly journals Transcription of Drosophila Troponin I Gene Is Regulated by Two Conserved, Functionally Identical, Synergistic Elements

2004 ◽  
Vol 15 (3) ◽  
pp. 1185-1196 ◽  
Author(s):  
María-Cruz Marín ◽  
José-Rodrigo Rodríguez ◽  
Alberto Ferrús
Keyword(s):  
Transcription Initiation ◽  
Troponin I ◽  
Regulatory Element ◽  
Expression Patterns ◽  
In Silico Analysis ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Upstream Regulatory Element ◽  
Transgenic Lines

The Drosophila wings-up A gene encodes Troponin I. Two regions, located upstream of the transcription initiation site (upstream regulatory element) and in the first intron (intron regulatory element), regulate gene expression in specific developmental and muscle type domains. Based on LacZ reporter expression in transgenic lines, upstream regulatory element and intron regulatory element yield identical expression patterns. Both elements are required for full expression levels in vivo as indicated by quantitative reverse transcription-polymerase chain reaction assays. Three myocyte enhancer factor-2 binding sites have been functionally characterized in each regulatory element. Using exon specific probes, we show that transvection is based on transcriptional changes in the homologous chromosome and that Zeste and Suppressor of Zeste 3 gene products act as repressors for wings-up A. Critical regions for transvection and for Zeste effects are defined near the transcription initiation site. After in silico analysis in insects (Anopheles and Drosophila pseudoobscura) and vertebrates (Ratus and Coturnix), the regulatory organization of Drosophila seems to be conserved. Troponin I (TnI) is expressed before muscle progenitors begin to fuse, and sarcomere morphogenesis is affected by TnI depletion as Z discs fail to form, revealing a novel developmental role for the protein or its transcripts. Also, abnormal stoichiometry among TnI isoforms, rather than their absolute levels, seems to cause the functional muscle defects.

scholarly journals RNA-seq: primary cells, cell lines and heat stress

2015 ◽  
Author(s):  
Carl J Schmdt ◽  
Elizabeth M Pritchett ◽  
Liang Sun ◽  
Richard V.N. Davis ◽  
Allen Hubbard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Sequence Data ◽  
Expression Patterns ◽  
Effective Means ◽  
Cost Effective ◽  
Rna Seq ◽  
Individual Gene ◽  
Examine Gene Expression ◽  
A Cell

Transcriptome analysis by RNA-seq has emerged as a high-throughput, cost-effective means to evaluate the expression pattern of genes in organisms. Unlike other methods, such as microarrays or quantitative PCR, RNA-seq is a target free method that permits analysis of essentially any RNA that can be amplified from a cell or tissue. At its most basic, RNA-seq can determine individual gene expression levels by counting the number of times a particular transcript was found in the sequence data. Transcript levels can be compared across multiple samples to identify differentially expressed genes and infer differences in biological states between the samples. We have used this approach to examine gene expression patterns in chicken and human cells, with particular interest in determining response to heat stress.

scholarly journals Comparative analysis of differential gene expression indicates divergence in ontogenetic strategies of leaves in two conifer genera

2021 ◽  
Author(s):  
Cynthia Webster ◽  
Laura Figueroa-Corona ◽  
Iván Méndez-González ◽  
Lluvia Soto-Álvarez ◽  
David Neale ◽  
...  
Keyword(s):  
Gene Expression ◽  
De Novo ◽  
Life Stage ◽  
Expression Patterns ◽  
Adult Life ◽  
Gene Interaction ◽  
Gene Families ◽  
Interaction Patterns ◽  
Gene Interaction Network ◽  
Stage Of Development

In land plants, heteroblasty broadly refers to a drastic change in morphology during growth through ontogeny. Juniperus flaccida and Pinus cembroides are conifers of independent lineages known to exhibit leaf heteroblasty between the juvenile and adult life stage of development. Juvenile leaves of P. cembroides develop spirally on the main stem and appear decurrent, flattened and needle-like; whereas, adult photosynthetic leaves are triangular or semi-circular needle-like, and grow in whorls on secondary or tertiary compact dwarf shoots. By comparison, J. flaccida juvenile leaves are decurrent and needle-like, and adult leaves are compact, short and scale-like. Comparative analyses were performed to evaluate differences in anatomy and gene expression patterns between developmental phases in both species. RNA from twelve samples was sequenced and analyzed with available software. They were assembled de novo from the RNA-Seq reads. Following assembly, 63,741 high quality transcripts were functionally annotated in P. cembroides and 69,448 in J. flaccida. Evaluation of the orthologous groups yielded 4,140 shared gene families among the four references (adult and juvenile from each species). Activities related to cell division and development were more abundant in juveniles than adults in P. cembroides, and more abundant in adults than juveniles in J. flaccida. Overall, there were 509 up-regulated and 81 down-regulated genes in the juvenile condition of P. cembroides and 18 up-regulated and 20 down-regulated in J. flaccida. Gene interaction network analysis showed evidence of co-expression and co-localization of up-regulated genes involved in cell wall and cuticle formation, development, and phenylpropanoid pathway, in juvenile P. cembroides leaves. Whereas in J. flaccida, differential expression and gene interaction patterns were detected in genes involved in photosynthesis and chloroplast biogenesis. Although J. flaccida and P. cembroides both exhibit leaf heteroblastic development, little overlap was detected and unique genes and pathways were highlighted in this study.

scholarly journals Learning Processes in Hierarchical Pairs Regulate Entire Gene Expression in Cells

2021 ◽  
Author(s):  
Tomoyuki Yamaguchi
Keyword(s):  
Gene Expression ◽  
Learning Process ◽  
Expression Patterns ◽  
Two Factors ◽  
Regulatory Cascades ◽  
Target Ratio ◽  
A Cell ◽  
The Difference ◽  
Genetically Determined ◽  
Entire Gene

Abstract Expression of numerous genes is precisely controlled in a cell in various contexts. While genetic and epigenetic mechanisms contribute to this regulation, how each mechanism cooperates to ensure the proper expression patterns of whole gene remains unclear. Here, I theoretically show that the repetition of simple biological processes makes appropriate whole-gene expression only if the appropriateness of current pattern is roughly detectable. A learning pair model is developed, in which two factors autonomously approach the target ratio by repeating two stochastic processes; competitive amplification with a small addition term and decay depending on the difference between the current and target ratios. Furthermore, thousands of factors are self-regulated in a hierarchical-pair architecture, in which the activation degrees competitively amplify, while transducing the activation signal, and decay at four different probabilities. Changes in whole-gene expression during human early embryogenesis and hematopoiesis are reproduced in simulation using this epigenetic learning process in a single genetically-determined hierarchical-pair architecture of gene regulatory cascades. On the background of this learning process, I propose the law of biological inertia which means that a living cell basically maintains the expression pattern while renewing the contents.

scholarly journals Developmental and spatial patterns of expression of the mouse homeobox gene, Hox 2.1

Development ◽  
1987 ◽  
Vol 99 (4) ◽  
pp. 603-617 ◽  
Author(s):  
R. Krumlauf ◽  
P.W. Holland ◽  
J.H. McVey ◽  
B.L. Hogan
Keyword(s):  
Gene Expression ◽  
Amino Acids ◽  
Spinal Cord ◽  
Homeobox Gene ◽  
Chromosome 11 ◽  
Cell Type Specificity ◽  
Acid Protein ◽  
Visceral Yolk Sac ◽  
Epithelial Cell Layer ◽  
A Cell

The Hox 2.1 gene forms part of a cluster of homeobox-containing genes on mouse chromosome 11. Analysis of Hox 2.1 cDNAs isolated from an 8 1/2-day p.c. mouse embryo library predicts that the gene encodes a 269 amino acid protein (Mr, 29,432). This deduced protein contains a homeobox 15 amino acids from the carboxy terminus and is very rich in serine and proline. A second partially conserved region present in several other genes containing homeoboxes, the hexapeptide Ile-Phe-Pro-Trp-Met-Arg, is located 12 amino acids upstream of the homeodomain and is encoded by a separate exon. Analysis of Hox 2.1 gene expression reveals a complex and tissue-specific series of RNA transcripts in a broad range of fetal tissues (lung, spinal cord, kidney, gut, spleen, liver and visceral yolk sac). Comparison of the temporal patterns of gene expression during development and in the adult suggests that Hox 2.1 is regulated independently in different tissues. Evidence is also presented that transcripts from other loci have extensive homology to the Hox 2.1 gene in sequences outside of the homeobox. In situ hybridization shows that Hox 2.1 transcripts are regionally localized in the spinal cord in an apparent anterior-posterior gradient extending from the hind brain. The distribution of RNA also displays a cell-type specificity in the lung, where mesodermal cells surrounding the branching epithelial cell layer accumulate high levels of Hox 2.1 transcripts.

Epigenetic Remodeling in Innate Immunity and Inflammation

2021 ◽  
Vol 39 (1) ◽  
Author(s):  
Qian Zhang ◽  
Xuetao Cao
Keyword(s):  
Gene Expression ◽  
Innate Immunity ◽  
Regulatory Element ◽  
Expression Patterns ◽  
Innate Immune ◽  
Annual Review ◽  
Specific Gene ◽  
Publication Date ◽  
Specific Expression ◽  
Epigenetic Remodeling

The innate immune response is a rapid response to pathogens or danger signals. It is precisely activated not only to efficiently eliminate pathogens but also to avoid excessive inflammation and tissue damage. cis-Regulatory element–associated chromatin architecture shaped by epigenetic factors, which we define as the epiregulome, endows innate immune cells with specialized phenotypes and unique functions by establishing cell-specific gene expression patterns, and it also contributes to resolution of the inflammatory response. In this review, we focus on two aspects: ( a) how niche signals during lineage commitment or following infection and pathogenic stress program epiregulomes by regulating gene expression levels, enzymatic activities, or gene-specific targeting of chromatin modifiers and ( b) how the programed epiregulomes in turn mediate regulation of gene-specific expression, which contributes to controlling the development of innate cells, or the response to infection and inflammation, in a timely manner. We also discuss the effects of innate immunometabolic rewiring on epiregulomes and speculate on several future challenges to be encountered during the exploration of the master regulators of epiregulomes in innate immunity and inflammation. Expected final online publication date for the Annual Review of Immunology, Volume 39 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Potential Autoregulation of Transcription Factor PU.1 by an Upstream Regulatory Element

2005 ◽  
Vol 25 (7) ◽  
pp. 2832-2845 ◽  
Author(s):  
Yutaka Okuno ◽  
Gang Huang ◽  
Frank Rosenbauer ◽  
Erica K. Evans ◽  
Hanna S. Radomska ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Reporter Gene ◽  
Regulatory Element ◽  
Mammalian Species ◽  
Critical Role ◽  
Homologous Region ◽  
Specific Expression ◽  
Upstream Regulatory Element

ABSTRACT Regulation of the hematopoietic transcription factor PU.1 (Spi-1) plays a critical role in the development of white cells, and abnormal expression of PU.1 can lead to leukemia. We previously reported that the PU.1 promoter cannot induce expression of a reporter gene in vivo, and cell-type-specific expression of PU.1 in stable lines was conferred by a 3.4-kb DNA fragment including a DNase I hypersensitive site located 14 kb upstream of the transcription start site. Here we demonstrate that this kb −14 site confers lineage-specific reporter gene expression in vivo. This kb −14 upstream regulatory element contains two 300-bp regions which are highly conserved in five mammalian species. In Friend virus-induced erythroleukemia, the spleen focus-forming virus integrates into the PU.1 locus between these two conserved regions. DNA binding experiments demonstrated that PU.1 itself and Elf-1 bind to a highly conserved site within the proximal homologous region in vivo. A mutation of this site abolishing binding of PU.1 and Elf-1 led to a marked decrease in the ability of this upstream element to direct activity of reporter gene in myelomonocytic cell lines. These data suggest that a potential positive autoregulatory loop mediated through an upstream regulatory element is essential for proper PU.1 gene expression.

Regulation of the uncoupling protein gene expression

1997 ◽  
Vol 136 (3) ◽  
pp. 251-264 ◽  
Author(s):  
J Enrique Silva ◽  
Rogerio Rabelo
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Thyroid Hormone ◽  
Uncoupling Protein ◽  
Regulatory Element ◽  
Gene Encoding ◽  
Response Elements ◽  
Brown Adipose ◽  
A Cell

Abstract Uncoupling protein (UCP) is essential to the thermogenic function of brown adipose tissue (BAT). The thermogenic role of this protein is due to its capacity to uncouple oxidative phosphorylation in a regulated manner. The thermogenic potential of BAT is determined by its content of UCP. The gene encoding this protein is under complex regulation. Catecholamines, via cAMP, thyroid hormone and retinoic acid, directly stimulate the gene acting upon an upstream (−2·28/−2·49 kb) enhancer sequence, but cAMP may act upon other sequences of the gene as well. CCAAT enhancer binding proteins and peroxisome proliferation activator receptor (PPAR)γ2 have also been implicated in the regulation of the gene acting on discrete sequences. While the thyroid hormone response and retinoic acid response elements (TRE and RARE) have been well defined, the cAMP response elements (CRE) remain elusive. The two TREs are 27 bp apart between −2·33 kb and −2·39 kb. The synergism between cAMP and thyroid hormone seems to reside in a 39 bp sequence downstream (−2·28/−2·32 kb). The most important CRE, the RARE, a cell-specific enhancer and a putative PPAR element are all concentrated in a 90 bp regulatory element of great complexity (−2·40/−22·49 kb). Other hormones, such as insulin and glucocorticoids, and IGF-I also modulate the expression of the gene but their effects seem to be largely indirect. Understanding the regulation of the UCP gene expression may facilitate the development of interventions in obesity and related disorders. European Journal of Endocrinology 136 251–264

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