scholarly journals THE INTERACTION OF GENETIC AND ENVIRONMENTAL FACTORS IN THE CONTROL OF AMYLASE GENE EXPRESSION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 114 (3) ◽  
pp. 943-954
Author(s):  
Bernhard F Benkel ◽  
Donal A Hickey
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Environmental Factors ◽  
Molecular Basis ◽  
Amylase Activity ◽  
Glucose Repression ◽  
Amylase Gene ◽  
Dietary Effects ◽  
Eukaryotic Gene ◽  
Genetic And Environmental Factors

ABSTRACT A number of previous studies have established that amylase activity can vary between Drosophila strains which are maintained under identical laboratory conditions. In addition, we have recently shown that all strains examined so far are subject to glucose repression of amylase activity. In this study, we show that the degree of glucose repression can vary between strains. Moreover, the glucose repression effect is much more pronounced in larvae than in adult flies. Our results lead to the conclusion that the strain-specific differences in activity and the dietary effects are not independent phenomena. These results have implications for the interpretation of many studies on amylase activity variation, including those experiments which have been designed to link amylase activity variations with fitness differences in nature. A question that naturally arises concerns the molecular basis for these strain-specific variations in the degree of glucose repression of this eukaryotic gene.

scholarly journals GLUCOSE REPRESSION OF AMYLASE GENE EXPRESSION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 114 (1) ◽  
pp. 137-144
Author(s):  
Bernhard F Benkel ◽  
Donal A Hickey
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Drosophila Melanogaster ◽  
Cyclic Amp ◽  
Xenopus Oocytes ◽  
Amylase Activity ◽  
Glucose Repression ◽  
Repressive Effect ◽  
Translatable Mrna ◽  
Effect Of Glucose

ABSTRACT We have previously shown that dietary glucose can reduce amylase activity in both adults and larvae of Drosophila; this reduction in enzyme activity reflects a reduction in the quantity of amylase protein, rather than an inhibition of enzyme activity. Here, we report that we have now defined conditions in which the repressive effect of glucose can be greater than 100-fold. Moreover, this repression is partially counteracted by the addition of exogenous cyclic AMP. We also show that there is a direct correlation between changes in amylase activity and changes in the amount of translatable mRNA as assayed in microinjected Xenopus oocytes. This means that the glucose repression is occurring at a pretranslational stage.

scholarly journals A short 5'-flanking region mediates glucose repression of amylase gene expression in Drosophila melanogaster.

Genetics ◽  
1993 ◽  
Vol 134 (2) ◽  
pp. 507-515 ◽  
Author(s):  
C Magoulas ◽  
L Bally-Cuif ◽  
A Loverre-Chyurlia ◽  
B Benkel ◽  
D Hickey
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Sequences ◽  
Glucose Repression ◽  
Essential Elements ◽  
Site Directed Mutagenesis ◽  
Deletion Analysis ◽  
Upstream Region ◽  
Directed Mutagenesis ◽  
Amylase Gene ◽  
Recombinant Gene

Abstract Expression of the alpha-amylase gene is highly repressed by dietary glucose in Drosophila melanogaster larvae. Here, we show that glucose repression is controlled by DNA sequences that are located upstream of the transcribed region. Recombinant gene constructions, in which the amylase promoter sequences were fused with the transcribed region of the Adh gene, were expressed in transgenic Drosophila larvae. The expression of ADH from the recombinant gene was shown to be subject to glucose repression. The function of potential regulatory cis-acting elements within the glucose responsive upstream region was examined by deletion analysis and by site-directed mutagenesis, coupled with expression assays in transformed larvae. The upstream deletion analysis showed that essential elements, both for overall activity and for glucose repression of the amylase gene, are located within a 109-bp region upstream of the transcription start site. Site-directed mutagenesis of these upstream sequences showed that the TATA motif, at position -31, and a novel 36-bp element, at position -109, were necessary for full activity of the amylase promoter. None of the introduced mutations resulted in loss of glucose responsiveness. These results indicate that glucose repression, in Drosophila, is mediated by transcriptional mechanisms that involve multiple, functionally redundant DNA elements.

scholarly journals Mechanisms and modifiers of methylmercury-induced neurotoxicity

2012 ◽  
Vol 1 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Stephanie J. B. Fretham ◽  
Samuel Caito ◽  
Ebany J. Martinez-Finley ◽  
Michael Aschner
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Environmental Factors ◽  
Genetic Polymorphisms ◽  
Experimental Studies ◽  
Mehg Exposure ◽  
Complete Understanding ◽  
Cellular Processes ◽  
Gene Environment ◽  
Genetic And Environmental Factors

Abstract The neurotoxic consequences of methylmercury (MeHg) exposure have long been known, however a complete understanding of the mechanisms underlying this toxicity is elusive. Recent epidemiological and experimental studies have provided mechanistic insights into the contribution of genetic and environmental factors that interact with MeHg to modify toxicity. This review will outline cellular processes directly and indirectly affected by MeHg, including oxidative stress, cellular signaling and gene expression, and discuss epigenetic modifications, genetic polymorphisms and gene–environment interactions capable of modifying MeHg neurotoxicity.

scholarly journals Nonsyndromic Deafness - Molecular Update

2009 ◽  
Vol 2 (1) ◽  
pp. 80-90 ◽  
Author(s):  
Piatto V.B ◽  
Secches L.V. ◽  
Arroyo M.A.S. ◽  
Lopes A.C.P. ◽  
Maniglia J.V.
Keyword(s):  
Hearing Loss ◽  
Environmental Factors ◽  
Molecular Basis ◽  
Nonsyndromic Hearing Loss ◽  
Vestibular Disorders ◽  
Nonsyndromic Deafness ◽  
Human Cochlea ◽  
Genetic And Environmental Factors ◽  
Molecular Description ◽  
Remarkable Progress

In most cases, hearing loss is a disorder caused by both genetic and environmental factors. The molecular description of deafness has experienced remarkable progress in the last decade, and it is emerging from the use of contemporary methods of cell and molecular biology. Currently, through the application of clinical and molecular genetics it is possible to identify genes associated with inherited, nonsyndromic deafness, and balance dysfunctions of the human cochlea. This brief review provides insights into nonsyndromic hearing loss, since the identification of the molecular basis for the inner ear function provides the basis for developing rational new approaches to diagnosis, management and treatment of auditory and vestibular disorders.

scholarly journals Metabolic Syndrome and Insulin resistance: Etiopathegenesis and influencing factors

2013 ◽  
Vol 4 (2) ◽  
pp. 26-31
Author(s):  
AK Al-Mahmood ◽  
SF Afrin ◽  
N Hoque
Keyword(s):  
Physical Activity ◽  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Signal Transduction ◽  
Environmental Factors ◽  
Molecular Basis ◽  
Genetic Factors ◽  
Genes Encoding ◽  
The Subject ◽  
Genetic And Environmental Factors

Metabolic syndrome and insulin resistance has been the subject of much debate over the last two decades. Its pathophysiologycal basis, however, still remains to be clearly understood. Both genetic and environmental factors have been implicated in its pathogenesis. Mutation of genes encoding signal transduction molecules of insulin and acquired factors like aging, diets, physical activity, obesity and related molecular changes, dyslipidemia, hypertension and smoking were proposed by many groups. This review examined both acquired and genetic factors and discussed model of hormone-receptor-postreceptor interactions to explore the molecular basis of insulin resistance. DOI: http://dx.doi.org/10.3329/bjmb.v4i2.13773 Bangladesh J Med Biochem 2011; 4(2): 26-31

Genetic and Environmental Factors Affecting Allergen-Related Gene Expression in Apple Fruit (Malus domestica L. Borkh)

2008 ◽  
Vol 56 (15) ◽  
pp. 6707-6716 ◽  
Author(s):  
Alessandro Botton ◽  
Paolo Lezzer ◽  
Alberto Dorigoni ◽  
Gianni Barcaccia ◽  
Benedetto Ruperti ◽  
...  
Keyword(s):  
Gene Expression ◽  
Environmental Factors ◽  
Malus Domestica ◽  
Apple Fruit ◽  
Related Gene ◽  
Factors Affecting ◽  
Genetic And Environmental Factors

Amylase cis-acting sequences mediate the alleviation of glucose repression by cAMP in Drosophila

1992 ◽  
Vol 70 (9) ◽  
pp. 751-757 ◽  
Author(s):  
Charalambos Magoulas ◽  
Ada Loverre-Chyurlia ◽  
Donal A. Hickey
Keyword(s):  
Gene Expression ◽  
Glucose Repression ◽  
Transcriptional Start Site ◽  
Minimal Length ◽  
Upstream Sequence ◽  
Wild Type ◽  
Amylase Gene ◽  
Glucose Effect ◽  
Base Pairs ◽  
Cis Acting

α-Amylase gene expression is highly repressed by dietary glucose in Drosophila melanogaster. This glucose effect can be alleviated by exogenous adenosine 3′:5′-cyclic monophosphate (cAMP). Here, we show that the relief of glucose repression by cAMP occurs at the level of amylase mRNA abundance. Furthermore, exogenous cAMP was shown to alleviate glucose repression of the transient expression of an amylase gene construct in transformed Amynull larvae. This construct contains only 109 base pairs of the promoter region; this is the minimal length of upstream sequence which is necessary for wild-type levels of amylase gene expression. These results indicate that cis-acting promoter elements located close to the transcriptional start site of the Drosophila amylase gene mediate both glucose repression and the cAMP-derepression effects.Key words: Drosophila, glucose repression, cAMP effect, amylase gene.

scholarly journals The European Map Butterfly Araschnia levana as a Model to Study the Molecular Basis and Evolutionary Ecology of Seasonal Polyphenism

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 325
Author(s):  
Arne Baudach ◽  
Andreas Vilcinskas
Keyword(s):  
Gene Expression ◽  
Environmental Factors ◽  
Epigenetic Regulation ◽  
Molecular Basis ◽  
Evolutionary Ecology ◽  
Hormonal Control ◽  
Day Length ◽  
Seasonal Polyphenism ◽  
Developmental Fate ◽  
Ecological Parameters

The European map butterfly Araschnia levana is a well-known example of seasonal polyphenism. Spring and summer imagoes exhibit distinct morphological phenotypes. Key environmental factors responsible for the expression of different morphs are day length and temperature. Larval exposure to light for more than 16 h per day entails direct development and results in the adult f. prorsa summer phenotype. Less than 15.5 h per day increasingly promotes diapause and the adult f. levana spring phenotype. The phenotype depends on the timing of the release of 20-hydroxyecdysone in pupae. Release within the first days after pupation potentially inhibits the default “levana-gene-expression-profile” because pre-pupae destined for diapause or subitaneous development have unique transcriptomic programs. Moreover, multiple microRNAs and their targets are differentially regulated during the larval and pupal stages, and candidates for diapause maintenance, duration, and phenotype determination have been identified. However, the complete pathway from photoreception to timekeeping and diapause or subitaneous development remains unclear. Beside the wing polyphenism, the hormonal and epigenetic modifications of the two phenotypes also include differences in biomechanical design and immunocompetence. Here, we discuss research on the physiological and molecular basis of polyphenism in A. levana, including hormonal control, epigenetic regulation, and the effect of ecological parameters on developmental fate.

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