scholarly journals Subclinical Pregnancy Toxemia-Induced Gene Expression Changes in Ovine Placenta and Uterus

2016 ◽  
Vol 3 ◽  
Author(s):  
Ramanathan K. Kasimanickam
Keyword(s):  
Gene Expression ◽  
Pregnancy Toxemia ◽  
Ovine Placenta

scholarly journals The differential effects of the timing of maternal nutrient restriction in the ovine placenta on glucocorticoid sensitivity, uncoupling protein 2, peroxisome proliferator-activated receptor-γ and cell proliferation

Reproduction ◽  
2009 ◽  
Vol 138 (3) ◽  
pp. 601-608 ◽  
Author(s):  
M Yiallourides ◽  
S P Sebert ◽  
V Wilson ◽  
D Sharkey ◽  
S M Rhind ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Fetal Growth ◽  
Uncoupling Protein ◽  
Nutrient Restriction ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Differential Effects ◽  
Glucocorticoid Sensitivity ◽  
Ovine Placenta

Nutrient restriction (NR) during critical windows of pregnancy has differential effects on placento-fetal growth and development. Our study, therefore, investigated developmental and metabolic adaptations within the ovine placenta following NR at different critical windows during the first 110 days of gestation (term=147 days). Thus, the effects of NR on cell proliferation, glucocorticoid sensitivity, IGF1 and 2 receptor, peroxisome proliferator-activated receptor γ (PPARG), and uncoupling protein (UCP)2 gene expression in the placenta were examined. Singleton bearing sheep (n=4–8 per group) were fed either 100% of their total metabolizable energy requirements throughout the study or 50% of this amount between 0–30, 31–65, 66–110, and 0–110 days gestation. A significant reduction in cell proliferation and increased gene expression for the glucocorticoid and IGF2 receptors, PPARG, and UCP2 were detected in placentae sampled from mothers who were nutrient restricted between days 66 and 110 of gestation, only, relative to controls. This window of gestation coincides with the maximum placental growth and the start of exponential growth of the fetus when there are substantially increased metabolic demands on the placenta compared with earlier in gestation. Consequently, increased glucocorticoid sensitivity and suppressed IGF2 action could contribute to a switch in the placenta from proliferation to differentiation, thereby improving its nutrient transfer capacity. Upregulation of PPARG and UCP2 would promote placental fatty acid metabolism thereby limiting glucose utilization. These compensatory placental responses may serve to maintain fetal growth but could result in adverse adaptations such as the early onset of the metabolic syndrome in later life.

Glucose transporter-1 gene expression in ovine placenta

Placenta ◽  
1994 ◽  
Vol 15 (7) ◽  
pp. A11 ◽  
Author(s):  
M.J. Currie ◽  
N.S. Bassett ◽  
P.D. Gluckman
Keyword(s):  
Gene Expression ◽  
Glucose Transporter ◽  
Glucose Transporter 1 ◽  
Ovine Placenta

Molecular and Microscopic Analysis of Altered Gene Expression in Transgenic and Gene Targeted Mice

1996 ◽  
Vol 54 ◽  
pp. 12-13
Author(s):  
W. K. Jones ◽  
J. Robbins
Keyword(s):  
Gene Expression ◽  
Pulmonary Veins ◽  
Microscopic Analysis ◽  
Mouse Tissue ◽  
Adult Heart ◽  
Heavy Chains ◽  
Altered Gene Expression ◽  
Altered Gene ◽  
Pulmonary Myocardium

Two myosin heavy chains (MyHC) are expressed in the mammalian heart and are differentially regulated during development. In the mouse, the α-MyHC is expressed constitutively in the atrium. At birth, the β-MyHC is downregulated and replaced by the α-MyHC, which is the sole cardiac MyHC isoform in the adult heart. We have employed transgenic and gene-targeting methodologies to study the regulation of cardiac MyHC gene expression and the functional and developmental consequences of altered α-MyHC expression in the mouse.We previously characterized an α-MyHC promoter capable of driving tissue-specific and developmentally correct expression of a CAT (chloramphenicol acetyltransferase) marker in the mouse. Tissue surveys detected a small amount of CAT activity in the lung (Fig. 1a). The results of in situ hybridization analyses indicated that the pattern of CAT transcript in the adult heart (Fig. 1b, top panel) is the same as that of α-MyHC (Fig. 1b, lower panel). The α-MyHC gene is expressed in a layer of cardiac muscle (pulmonary myocardium) associated with the pulmonary veins (Fig. 1c). These studies extend our understanding of α-MyHC expression and delimit a third cardiac compartment.

Linking transcription, RNA polymerase II elongation and alternative splicing

2020 ◽  
Vol 477 (16) ◽  
pp. 3091-3104 ◽  
Author(s):  
Luciana E. Giono ◽  
Alberto R. Kornblihtt
Keyword(s):  
Gene Expression ◽  
Alternative Splicing ◽  
Rna Polymerase Ii ◽  
Environmental Changes ◽  
Transcription Elongation ◽  
Single Gene ◽  
Regulation Of Gene Expression ◽  
Regulation Of Transcription ◽  
Stepping Stones ◽  
Eukaryotic Transcription

Gene expression is an intricately regulated process that is at the basis of cell differentiation, the maintenance of cell identity and the cellular responses to environmental changes. Alternative splicing, the process by which multiple functionally distinct transcripts are generated from a single gene, is one of the main mechanisms that contribute to expand the coding capacity of genomes and help explain the level of complexity achieved by higher organisms. Eukaryotic transcription is subject to multiple layers of regulation both intrinsic — such as promoter structure — and dynamic, allowing the cell to respond to internal and external signals. Similarly, alternative splicing choices are affected by all of these aspects, mainly through the regulation of transcription elongation, making it a regulatory knob on a par with the regulation of gene expression levels. This review aims to recapitulate some of the history and stepping-stones that led to the paradigms held today about transcription and splicing regulation, with major focus on transcription elongation and its effect on alternative splicing.

Role of small nuclear RNAs in eukaryotic gene expression

2013 ◽  
Vol 54 ◽  
pp. 79-90 ◽  
Author(s):  
Saba Valadkhan ◽  
Lalith S. Gunawardane
Keyword(s):  
Gene Expression ◽  
Protein Interactions ◽  
Rna Stability ◽  
Splice Sites ◽  
Branch Site ◽  
Small Nuclear Rnas ◽  
Eukaryotic Gene Expression ◽  
Eukaryotic Gene ◽  
Rna Biogenesis

Eukaryotic cells contain small, highly abundant, nuclear-localized non-coding RNAs [snRNAs (small nuclear RNAs)] which play important roles in splicing of introns from primary genomic transcripts. Through a combination of RNA–RNA and RNA–protein interactions, two of the snRNPs, U1 and U2, recognize the splice sites and the branch site of introns. A complex remodelling of RNA–RNA and protein-based interactions follows, resulting in the assembly of catalytically competent spliceosomes, in which the snRNAs and their bound proteins play central roles. This process involves formation of extensive base-pairing interactions between U2 and U6, U6 and the 5′ splice site, and U5 and the exonic sequences immediately adjacent to the 5′ and 3′ splice sites. Thus RNA–RNA interactions involving U2, U5 and U6 help position the reacting groups of the first and second steps of splicing. In addition, U6 is also thought to participate in formation of the spliceosomal active site. Furthermore, emerging evidence suggests additional roles for snRNAs in regulation of various aspects of RNA biogenesis, from transcription to polyadenylation and RNA stability. These snRNP-mediated regulatory roles probably serve to ensure the co-ordination of the different processes involved in biogenesis of RNAs and point to the central importance of snRNAs in eukaryotic gene expression.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

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