scholarly journals RNase reverses segment sequence in the anterior of a beetle egg (Callosobruchus maculatus, Coleoptera)

2016 ◽  
Author(s):  
Jitse M. van der Meer
Keyword(s):  
Callosobruchus Maculatus ◽  
Genetic Regulation ◽  
Enzyme Concentration ◽  
Mirror Image ◽  
Regulatory Mechanisms ◽  
Segment Sequence ◽  
Cytoplasmic Rna ◽  
Regulation Mechanisms ◽  
Anterior Segments ◽  
Segment Pattern

AbstractThe genetic regulation of anterior-posterior segment pattern development has been elucidated in detail for Drosophila, but it is not canonical for insects. A surprising diversity of regulatory mechanisms is being uncovered not only between insect Orders, but also within the Order of the Diptera. This raises the question whether the same diversity of regulatory mechanisms exists within other insect Orders. This paper draws attention to the promise of the pea beetle Callosobruchus maculatus for elucidating the evolution of pattern regulation mechanisms in Coleoptera and other insect Orders. Introduction of RNase in eggs of Callosobruchus replaces anterior segments with posterior segments oriented in mirror image symmetry to the original posterior segments (double abdomens). Reversal is specific for RNase activity, for treatment of the anterior egg pole and for cytoplasmic RNA. Yield depends on developmental stage, enzyme concentration and temperature. A maximum of 30% of treated eggs reversed segment sequence after puncture in 10.0 μg/ml RNase S reconstituted from S-protein and S-peptide at 30 °C. This result sets the stage for an analysis of the genetic regulation of segment pattern formation in the long germ embryo of the Coleopteran Callosobruchus and for comparison with the short germ embryo of the Coleopteran Tribolium.

Instability of the anteroposterior axis in spontaneous double abdomen (sda), a genetic variant of Chironomus samoensis (Diptera, Chironomidae)

Development ◽  
1987 ◽  
Vol 101 (3) ◽  
pp. 591-603 ◽  
Author(s):  
K.L. Kuhn ◽  
J. Percy ◽  
M. Laurel ◽  
K. Kalthoff
Keyword(s):  
Genetic Variant ◽  
Laboratory Strain ◽  
Posterior Pole ◽  
Mirror Image ◽  
Anterior Pole ◽  
Spontaneous Formation ◽  
Pole Cells ◽  
Anterior Segments ◽  
Egg Polarity

We have isolated a laboratory strain of Chironomus samoensis in which determination of the anteroposterior egg polarity is disturbed. Most conspicuous is the spontaneous formation of ‘double abdomen’ embryos where head and thorax are replaced by a mirror image of the abdomen. Such double abdomens are found in about half of the egg clusters in this strain, which we call the spontaneous double abdomen (sda) strain as opposed to the normal (N) strain. Also observed in the sda strain, although less frequently, are ‘double cephalon’ embryos showing a mirror-image duplication of cephalic segments in the absence of thorax and abdomen. Moreover, embryos from the sda strain tend to form cells at the anterior pole resembling the pole cells at the posterior pole. Reciprocal crossings between the sda and the N strain indicate that the sda trait is inherited maternally. Spontaneous double abdomen formation is correlated with signs of disturbed egg architecture, including extruded yolk and detached cells. Double cephalons can also be generated by centrifuging embryos from the N strain, whereas centrifugation of sda embryos produces mostly double abdomens. Double abdomen formation can be induced experimentally by anterior u.v. irradiation of embryos from either strain. The sda trait and u.v. irradiation act in a synergistic fashion. The data suggest that the sda trait may be caused by one or more genomic mutations interfering indirectly with the activity of anterior determinants, i.e. cytoplasmic RNP particles necessary for the development of anterior segments. The sda defects may be ascribed to alterations in cytoskeletal components involved in anchoring anterior determinants and segregating them into anterior blastoderm cells.

scholarly journals 373 MITOCHONDRIAL RESPIRATlON OF `HASS' AVOCADOS IN RESPONSE TO ELEVATED CO, CONCENTRATIONS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 484e-484 ◽  
Author(s):  
Diana Dostal Lange ◽  
Adel A. Kader
Keyword(s):  
Carbon Dioxide ◽  
Cytochrome Oxidase ◽  
Immunoblot Analysis ◽  
Enzyme Concentration ◽  
Regulatory Mechanisms ◽  
Respiratory Enzymes ◽  
Tolerance Level ◽  
Avocado Fruit ◽  
Co Concentrations

Carbon dioxide-enriched atmospheres can be effective in the retardation of ripening and in the reduction of decay of horticultural commodities. However, concentrations in excess of the tolerance level may cause physiological damage. The goal of our research is to elucidate the specific regulatory mechanisms of CO2 actions. Cytochrome oxidase (CytOx) in vitro activity in preclimacteric avocado fruit stored in air or 40% CO2 + 12.6% O2 was evaluated at 20C. Activities were determined during treatment and also after a transfer to air. Fruit treated with 40% CO2 + 12.6% O2 had elevated CytOx in vitro activity when compared to air-stored fruit. Immunoblot analysis was performed to determine if the increase in CytOx activity could be due to an increase in enzyme concentration. The decline in respiration rate of CO,-treated fruit was most likely due to the decrease in intracellular pH and its effect on the activities of important respiratory enzymes, including CytOx. The regulatory mechanisms of other mitochondrial respiratory enzymes in `Hass' avocados exposed to elevated CO2 atmospheres are also under investigation.

scholarly journals Revisiting the Regulation of the Primary Scaffoldin Gene in Clostridium thermocellum

2017 ◽  
Vol 83 (8) ◽  
Author(s):  
Lizett Ortiz de Ora ◽  
Iván Muñoz-Gutiérrez ◽  
Edward A. Bayer ◽  
Yuval Shoham ◽  
Raphael Lamed ◽  
...  
Keyword(s):  
Plant Cell Wall ◽  
Consolidated Bioprocessing ◽  
Present Report ◽  
Genetic Regulation ◽  
Regulatory Mechanisms ◽  
Start Codon ◽  
Protein Subunit ◽  
Cell Wall Polysaccharides ◽  
Stem Loop ◽  
Content Type

ABSTRACT Cellulosomes are considered to be one of the most efficient systems for the degradation of plant cell wall polysaccharides. The central cellulosome component comprises a large, noncatalytic protein subunit called scaffoldin. Multiple saccharolytic enzymes are incorporated into the scaffoldins via specific high-affinity cohesin-dockerin interactions. Recently, the regulation of genes encoding certain cellulosomal components by multiple RNA polymerase alternative σI factors has been demonstrated in Clostridium (Ruminiclostridium) thermocellum. In the present report, we provide experimental evidence demonstrating that the C. thermocellum cipA gene, which encodes the primary cellulosomal scaffoldin, is regulated by several alternative σI factors and by the vegetative σA factor. Furthermore, we show that previously suggested transcriptional start sites (TSSs) of C. thermocellum cipA are actually posttranscriptional processed sites. By using comparative bioinformatic analysis, we have also identified highly conserved σI- and σA-dependent promoters upstream of the primary scaffoldin-encoding genes of other clostridia, namely, Clostridium straminisolvens, Clostridium clariflavum, Acetivibrio cellulolyticus, and Clostridium sp. strain Bc-iso-3. Interestingly, a previously identified TSS of the primary scaffoldin CbpA gene of Clostridium cellulovorans matches the predicted σI-dependent promoter identified in the present work rather than the previously proposed σA promoter. With the exception of C. cellulovorans, both σI and σA promoters of primary scaffoldin genes are located more than 600 nucleotides upstream of the start codon, yielding long 5′-untranslated regions (5′-UTRs). Furthermore, these 5′-UTRs have highly conserved stem-loop structures located near the start codon. We propose that these large 5′-UTRs may be involved in the regulation of both the primary scaffoldin and other cellulosomal components. IMPORTANCE Cellulosome-producing bacteria are among the most effective cellulolytic microorganisms known. This group of bacteria has biotechnological potential for the production of second-generation biofuels and other biocommodities from cellulosic wastes. The efficiency of cellulose hydrolysis is due to their cellulosomes, which arrange enzymes in close proximity on the cellulosic substrate, thereby increasing synergism among the catalytic domains. The backbone of these multienzyme nanomachines is the scaffoldin subunit, which has been the subject of study for many years. However, its genetic regulation is poorly understood. Hence, from basic and applied points of view, it is imperative to unravel the regulatory mechanisms of the scaffoldin genes. The understanding of these regulatory mechanisms can help to improve the performance of the industrially relevant strains of C. thermocellum and related cellulosome-producing bacteria en route to the consolidated bioprocessing of biomass.

scholarly journals 1-Anilinonaphthalene-8-sulphonate, a fluorescent conformational probe for glutamate dehydrogenase

1969 ◽  
Vol 114 (2) ◽  
pp. 407-417 ◽  
Author(s):  
G. H. Dodd ◽  
G. K. Radda
Keyword(s):  
Ionic Strength ◽  
Glutamate Dehydrogenase ◽  
Structural Transition ◽  
Enzyme Concentration ◽  
Regulatory Mechanisms ◽  
Conformational Equilibria ◽  
Allosteric Transitions

1. The interaction of 1-anilinonaphthalene-8-sulphonate with ox liver glutamate dehydrogenase was examined. 2. The fluorescence of the dye is enhanced 100-fold on binding. 3. A further enhancement is observed when NADH and GTP are added to the enzyme. 4. By using this property of the dye to measure conformational equilibria in the enzyme the effects of coenzyme, inhibitors, enzyme concentration, ionic strength and pH on the allosteric transitions were studied. 5. GTP and NADH interact with the enzyme in a heterotropic manner. 6. The rate of the structural transition brought about by GTP and NADH is biphasic with half-lives of 34 and 200msec. 7. The relation of these observations to regulatory mechanisms is discussed.

scholarly journals Genetic regulation of DNA methylation across tissues reveals thousands of molecular links to complex traits

2021 ◽  
Author(s):  
Meritxell Oliva ◽  
Kathryn Demanelis ◽  
Farzana Jasmine ◽  
Yihao Lu ◽  
Habibul Hahsan ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Complex Traits ◽  
Tissue Specificity ◽  
Genetic Regulation ◽  
Tissue Expression ◽  
Regulatory Mechanisms ◽  
Rna Seq ◽  
Functional Elements ◽  
Phenotype Data ◽  
Molecular Regulatory Mechanisms

Abstract Epigenetic modifications of chromosomes, including DNA methylation (DNAm), play a fundamental role in gene regulation in humans. We generated DNAm data for 987 samples from the Genotype-Tissue Expression (GTEx) project, representing 9 tissue types and 424 subjects. We integrated GTEx RNA-seq data to examine methylome-transcriptome associations, their tissue specificity, and their overlap with regulatory regions. We mapped DNAm quantitative trait loci in cis (mQTLs), contrasted mQTLs with expression QTLs (eQTLs) with respect to functional elements, and assessed their relative contributions to complex traits. We identified thousands of mQTL links to traits in locations lacking a relevant eQTL. By integrating genetic, diverse -omics and phenotype data, we contribute to the understanding of molecular regulatory mechanisms in human tissues and their association with complex traits.

scholarly journals Divergence in alternative polyadenylation contributes to gene regulatory differences between humans and chimpanzees

2020 ◽  
Author(s):  
Briana Mittleman ◽  
Sebastian Pott ◽  
Shane Warland ◽  
Kenneth Barr ◽  
Claudia Cuevas ◽  
...  
Keyword(s):  
Protein Expression ◽  
Species Differences ◽  
Genetic Regulation ◽  
Alternative Polyadenylation ◽  
Transcript Level ◽  
Protein Translation ◽  
Regulatory Mechanisms ◽  
Genomic Studies ◽  
Gene Regulatory ◽  
Transcriptional Regulatory Mechanisms

AbstractComparative functional genomic studies have shown that differences in gene expression between species can often be explained by corresponding inter-species differences in genetic and epigenetic regulatory mechanisms. In the quest to understand gene regulatory evolution in primates, the role of co-transcriptional regulatory mechanisms, such as alternative polyadenylation (APA), have so far received little attention. To begin addressing this gap, we studied APA in lymphoblastoid cell lines from six humans and six chimpanzees, and estimated usage for 44,432 polyadenylation sites (PAS) in 9,518 genes in both species. While APA is largely conserved in humans and chimpanzees, we identified 1,705 genes with significantly different PAS usage (FDR of 0.05) between the two species. We found that genes with divergent APA patterns are enriched among differentially expressed genes, as well as among genes that show differences in protein translation between species. In particular, differences in APA between humans and chimpanzees can explain a subset of observed inter-species protein expression differences that do not display corresponding differences at the transcript level. Finally, we focused on genes that have a dominant PAS, namely a PAS that is used more often than all others. Dominant PAS are highly conserved, and inter-species differences in dominant PAS are particularly enriched for genes that also show expression differences between the species. This study establishes APA as another key mechanism underlying the genetic regulation of transcript and protein expression levels in primates.

scholarly journals A Multi-Parameter Analysis of Cellular Coordination of Major Transcriptome Regulation Mechanisms

2017 ◽  
Author(s):  
Wen Jiang ◽  
Zhanyong Guo ◽  
Nuno Lages ◽  
W. Jim Zheng ◽  
Denis Feliers ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Regulatory Mechanism ◽  
Negative Relationship ◽  
Parameter Analysis ◽  
Regulatory Mechanisms ◽  
Statistical Features ◽  
Transcriptome Regulation ◽  
Coordination Process ◽  
Regulation Mechanisms ◽  
The Relationship

AbstractTo understand cellular coordination of multiple transcriptome regulation mechanisms, we simultaneously measured transcription rate (TR), mRNA abundance (RA) and translation activity (TA). This revealed multiple quantitative insights. First, the genomic profiles of the three parameters are systematically different in key statistical features. Sequentially more genes exhibit extreme low or high expression values from TR to RA, then to TA. That is, because of cellular coordination of these regulatory mechanisms, sequentially higher levels of gene expression selectivity are achieved as genetic information flow from the genome to the proteome. Second, the contribution of the stabilization-by-translation regulatory mechanism to the cellular coordination process was assessed. The data enabled an estimation of mRNA stability, revealing a moderate but significant positive correlation between the estimated mRNA stability and translation activity. Third, the proportion of a mRNA occupied by un-translated regions (UTR) exhibits a negative relationship with the level of this correlation, and is thus a major determinant of the mode of regulation of the mRNA. High-UTR-proportion mRNAs tend to defy the stabilization-by-translation regulatory mechanism, staying out of the polysome but remaining stable; mRNAs with little UTRs largely follow this regulation. In summary, we quantitatively delineated the relationship among multiple transcriptome regulation parameters, i.e., cellular coordination of corresponding regulatory mechanisms.

scholarly journals The Role of MicroRNAs in Mammalian Fertility: From Gametogenesis to Embryo Implantation

2020 ◽  
Vol 21 (2) ◽  
pp. 585 ◽  
Author(s):  
Dessie Salilew-Wondim ◽  
Samuel Gebremedhn ◽  
Michael Hoelker ◽  
Ernst Tholen ◽  
Tsige Hailay ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Ovarian Tissue ◽  
Genetic Regulation ◽  
Adult Life ◽  
Subsequent Development ◽  
Early Embryo ◽  
Regulatory Mechanisms ◽  
Developmental Processes ◽  
Transcriptional Regulatory Mechanisms

The genetic codes inscribed during two key developmental processes, namely gametogenesis and embryogenesis, are believed to determine subsequent development and survival of adult life. Once the embryo is formed, its further development mainly depends on its intrinsic characteristics, maternal environment (the endometrial receptivity), and the embryo–maternal interactions established during each phase of development. These developmental processes are under strict genetic regulation that could be manifested temporally and spatially depending on the physiological and developmental status of the cell. MicroRNAs (miRNAs), one of the small non-coding classes of RNAs, approximately 19–22 nucleotides in length, are one of the candidates for post-transcriptional developmental regulators. These tiny non-coding RNAs are expressed in ovarian tissue, granulosa cells, testis, oocytes, follicular fluid, and embryos and are implicated in diverse biological processes such as cell-to-cell communication. Moreover, accumulated evidences have also highlighted that miRNAs can be released into the extracellular environment through different mechanisms facilitating intercellular communication. Therefore, understanding miRNAs mediated regulatory mechanisms during gametogenesis and embryogenesis provides further insights about the molecular mechanisms underlying oocyte/sperm formation, early embryo development, and implantation. Thus, this review highlights the role of miRNAs in mammalian gametogenesis and embryogenesis and summarizes recent findings about miRNA-mediated post-transcriptional regulatory mechanisms occurring during early mammalian development.

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