scholarly journals Model and Non-model Insects in Chronobiology

2020 ◽  
Vol 14 ◽  
Author(s):  
Katharina Beer ◽  
Charlotte Helfrich-Förster
Keyword(s):  
Circadian Clock ◽  
Genetic Manipulation ◽  
Model Organism ◽  
Fruit Fly ◽  
Sun Compass ◽  
Clock Networks ◽  
The Social ◽  
And Function ◽  
Circadian Behavior ◽  
Photoperiodic Diapause

The fruit fly Drosophila melanogaster is an established model organism in chronobiology, because genetic manipulation and breeding in the laboratory are easy. The circadian clock neuroanatomy in D. melanogaster is one of the best-known clock networks in insects and basic circadian behavior has been characterized in detail in this insect. Another model in chronobiology is the honey bee Apis mellifera, of which diurnal foraging behavior has been described already in the early twentieth century. A. mellifera hallmarks the research on the interplay between the clock and sociality and complex behaviors like sun compass navigation and time-place-learning. Nevertheless, there are aspects of clock structure and function, like for example the role of the clock in photoperiodism and diapause, which can be only insufficiently investigated in these two models. Unlike high-latitude flies such as Chymomyza costata or D. ezoana, cosmopolitan D. melanogaster flies do not display a photoperiodic diapause. Similarly, A. mellifera bees do not go into “real” diapause, but most solitary bee species exhibit an obligatory diapause. Furthermore, sociality evolved in different Hymenoptera independently, wherefore it might be misleading to study the social clock only in one social insect. Consequently, additional research on non-model insects is required to understand the circadian clock in Diptera and Hymenoptera. In this review, we introduce the two chronobiology model insects D. melanogaster and A. mellifera, compare them with other insects and show their advantages and limitations as general models for insect circadian clocks.

scholarly journals Chromatin Structure and Function in Mosquitoes

2020 ◽  
Vol 11 ◽  
Author(s):  
Óscar M. Lezcano ◽  
Miriam Sánchez-Polo ◽  
José L. Ruiz ◽  
Elena Gómez-Díaz
Keyword(s):  
Drosophila Melanogaster ◽  
Regulatory Networks ◽  
Genome Structure ◽  
Nuclear Architecture ◽  
Model Organism ◽  
Fruit Fly ◽  
Model Organisms ◽  
Epigenetic Mechanisms ◽  
West Nile Fever ◽  
And Function

The principles and function of chromatin and nuclear architecture have been extensively studied in model organisms, such as Drosophila melanogaster. However, little is known about the role of these epigenetic processes in transcriptional regulation in other insects including mosquitoes, which are major disease vectors and a worldwide threat for human health. Some of these life-threatening diseases are malaria, which is caused by protozoan parasites of the genus Plasmodium and transmitted by Anopheles mosquitoes; dengue fever, which is caused by an arbovirus mainly transmitted by Aedes aegypti; and West Nile fever, which is caused by an arbovirus transmitted by Culex spp. In this contribution, we review what is known about chromatin-associated mechanisms and the 3D genome structure in various mosquito vectors, including Anopheles, Aedes, and Culex spp. We also discuss the similarities between epigenetic mechanisms in mosquitoes and the model organism Drosophila melanogaster, and advocate that the field could benefit from the cross-application of state-of-the-art functional genomic technologies that are well-developed in the fruit fly. Uncovering the mosquito regulatory genome can lead to the discovery of unique regulatory networks associated with the parasitic life-style of these insects. It is also critical to understand the molecular interactions between the vectors and the pathogens that they transmit, which could hold the key to major breakthroughs on the fight against mosquito-borne diseases. Finally, it is clear that epigenetic mechanisms controlling mosquito environmental plasticity and evolvability are also of utmost importance, particularly in the current context of globalization and climate change.

scholarly journals InterMOD: integrated data and tools for the unification of model organism research

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Julie Sullivan ◽  
Kalpana Karra ◽  
Sierra A. T. Moxon ◽  
Andrew Vallejos ◽  
Howie Motenko ◽  
...  
Keyword(s):  
Comparative Research ◽  
Model Organism ◽  
Genomic Analysis ◽  
Fruit Fly ◽  
Model Organisms ◽  
Basic Biology ◽  
Set Up ◽  
And Function ◽  
Model Organism Databases ◽  
Nematode Worm

Abstract Model organisms are widely used for understanding basic biology and have significantly contributed to the study of human disease. In recent years, genomic analysis has provided extensive evidence of widespread conservation of gene sequence and function amongst eukaryotes, allowing insights from model organisms to help decipher gene function in a wider range of species. The InterMOD consortium is developing an infrastructure based around the InterMine data warehouse system to integrate genomic and functional data from a number of key model organisms, leading the way to improved cross-species research. So far including budding yeast, nematode worm, fruit fly, zebrafish, rat and mouse, the project has set up data warehouses, synchronized data models and created analysis tools and links between data from different species. The project unites a number of major model organism databases, improving both the consistency and accessibility of comparative research, to the benefit of the wider scientific community.

scholarly journals Quantitative investigation reveals distinct phases in Drosophila sleep

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaochan Xu ◽  
Wei Yang ◽  
Binghui Tian ◽  
Xiuwen Sui ◽  
Weilai Chi ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
General Pattern ◽  
Model Organism ◽  
Infrared Camera ◽  
Fruit Fly ◽  
Genetic Dissection ◽  
Power Law Distribution ◽  
Quantitative Investigation ◽  
Waking Up ◽  
Set Up

AbstractThe fruit fly, Drosophila melanogaster, has been used as a model organism for the molecular and genetic dissection of sleeping behaviors. However, most previous studies were based on qualitative or semi-quantitative characterizations. Here we quantified sleep in flies. We set up an assay to continuously track the activity of flies using infrared camera, which monitored the movement of tens of flies simultaneously with high spatial and temporal resolution. We obtained accurate statistics regarding the rest and sleep patterns of single flies. Analysis of our data has revealed a general pattern of rest and sleep: the rest statistics obeyed a power law distribution and the sleep statistics obeyed an exponential distribution. Thus, a resting fly would start to move again with a probability that decreased with the time it has rested, whereas a sleeping fly would wake up with a probability independent of how long it had slept. Resting transits to sleeping at time scales of minutes. Our method allows quantitative investigations of resting and sleeping behaviors and our results provide insights for mechanisms of falling into and waking up from sleep.

scholarly journals Quantum and systems theory in world society: Not brothers and sisters but relatives still?

2020 ◽  
Vol 51 (5) ◽  
pp. 434-449 ◽  
Author(s):  
Mathias Albert ◽  
Felix Maximilian Bathon
Keyword(s):  
Quantum Theory ◽  
International Relations ◽  
Systems Theory ◽  
World View ◽  
Social World ◽  
Critical Engagement ◽  
The Social ◽  
Social Theories ◽  
Entire World ◽  
And Function

This article provides a sympathetic, yet also somewhat critical, engagement with the notion of ‘quantizing’ by exploring substantive overlaps between quantum and systems theory. It is based on the observation that while quantum theory is ‘non-classical’ in its entire world-view, there is a danger that when it comes to the social world it is simply laid on a world-view of that world, which remains at its core ‘classical’. This situation calls for engaging quantum with existing non-classical social theories. Resemblances between quantum and systems theory are obviously given through similarities around the concepts of observation and meaning, whose status and function in both bodies of theory is explored. We then probe the degree to which obvious analogies in fact could be read as overlaps and similarities that could be put to complementary analytical use: in a sense, we argue that systems theory ‘does’ quantum theory, and vice versa. The article concludes with some vistas of this discussion for the field of international relations.

scholarly journals Lactose-Inducible System for Metabolic Engineering of Clostridium ljungdahlii

2014 ◽  
Vol 80 (8) ◽  
pp. 2410-2416 ◽  
Author(s):  
Areen Banerjee ◽  
Ching Leang ◽  
Toshiyuki Ueki ◽  
Kelly P. Nevin ◽  
Derek R. Lovley
Keyword(s):  
Ethanol Production ◽  
Genetic Manipulation ◽  
Electron Flow ◽  
Model Organism ◽  
Inducible Expression ◽  
Carbon Flow ◽  
Wild Type ◽  
Content Type ◽  
Microbial Electrosynthesis ◽  
Clostridium Ljungdahlii

ABSTRACTThe development of tools for genetic manipulation ofClostridium ljungdahliihas increased its attractiveness as a chassis for autotrophic production of organic commodities and biofuels from syngas and microbial electrosynthesis and established it as a model organism for the study of the basic physiology of acetogenesis. In an attempt to expand the genetic toolbox forC. ljungdahlii, the possibility of adapting a lactose-inducible system for gene expression, previously reported forClostridium perfringens, was investigated. The plasmid pAH2, originally developed forC. perfringenswith agusAreporter gene, functioned as an effective lactose-inducible system inC. ljungdahlii. Lactose induction ofC. ljungdahliicontaining pB1, in which the gene for the aldehyde/alcohol dehydrogenase AdhE1 was downstream of the lactose-inducible promoter, increased expression ofadhE130-fold over the wild-type level, increasing ethanol production 1.5-fold, with a corresponding decrease in acetate production. Lactose-inducible expression ofadhE1in a strain in whichadhE1and theadhE1homologadhE2had been deleted from the chromosome restored ethanol production to levels comparable to those in the wild-type strain. Inducing expression ofadhE2similarly failed to restore ethanol production, suggesting thatadhE1is the homolog responsible for ethanol production. Lactose-inducible expression of the four heterologous genes necessary to convert acetyl coenzyme A (acetyl-CoA) to acetone diverted ca. 60% of carbon flow to acetone production during growth on fructose, and 25% of carbon flow went to acetone when carbon monoxide was the electron donor. These studies demonstrate that the lactose-inducible system described here will be useful for redirecting carbon and electron flow for the biosynthesis of products more valuable than acetate. Furthermore, this tool should aid in optimizing microbial electrosynthesis and for basic studies on the physiology of acetogenesis.

Concession Agreements and Nationalization

1958 ◽  
Vol 52 (2) ◽  
pp. 260-279 ◽  
Author(s):  
Kenneth S. Carlston
Keyword(s):  
International Law ◽  
Clear Understanding ◽  
Legal Rules ◽  
Social Facts ◽  
The Social ◽  
The Status ◽  
And Function ◽  
International Economies

It is the purpose of this article to investigate the status of concession agreements in the light of the rules of international law bearing on the power of a state to nationalize property. It is a continuation of an earlier article which explored the nature and function of the concession agreement in the national and international economies. The first article rested on the assumption that legal rules could not be fully understood or evaluated without a fairly clear understanding of the social facts which they were designed to regulate.

scholarly journals A54 THE CIRCADIAN CLOCK INFLUENCES JAK/STAT SIGNALING AND GUT PERMEABILITY

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 11-12
Author(s):  
K Parasram ◽  
D Bachetti ◽  
P Karpowicz
Keyword(s):  
Circadian Clock ◽  
Clock Cycle ◽  
Intestinal Barrier ◽  
Fruit Fly ◽  
Cell Types ◽  
Time Of Day ◽  
Acute Injury ◽  
Intestinal Barrier Function ◽  
Intestinal Immunity ◽  
Stat Signaling

Abstract Background The circadian clock is a 24-hour feedback loop that drives rhythms in behaviours and physiological processes. This molecular timekeeper consists of the transcription factors, Clock-Cycle, that drive expression of thousands of clock-controlled genes, with two of these, Period and Timeless, acting as negative regulators of Clock-Cycle. This fundamental mechanism was initially characterized in the fruit fly, Drosophila melanogaster (Nobel Prize in Physiology & Medicine, 2017), and is highly conserved in humans. The intestine, or midgut, of Drosophila, is also similar to the human small intestine consisting of similar cellular lineage, signaling pathways, and physiological functions. The lineage of the Drosophila intestine contains the same four cell types as humans: intestinal stem cells (ISCs), progenitors called enteroblasts, enterocytes and enteroendocrine cells. This simplified lineage as well as the genetic tools available, make Drosophila an ideal model for intestinal regeneration in health and disease. We have previously shown that the circadian clock is active in ISCs, EBs and ECs during both homeostatic and regenerating conditions. Furthermore, the circadian clock regulates the mitosis of ISCs under regenerating conditions. Aims We sought to uncover if Jak/STAT signaling, one of the key pathways involved in ISC proliferation in the Drosophila intestine, shows a circadian rhythm and if there is a time-of-day difference in the regenerative response. Methods To test whether the clock regulates Jak/STAT during acute injury, we developed an irradiation assay that does not affect survival but acutely disrupts intestinal barrier function. Results Using a dynamic reporter of Jak/STAT activity we show that Period circadian clock mutants have low Jak/STAT signaling and a leaky gut phenotype. Wildtype controls show time-dependent gut leakiness upon irradiation, which is higher and time-independent in Period mutants. The level of Jak/STAT response differs depending on the time of irradiation in the controls, but is higher at all times in the mutants. Conclusions The Jak/Stat pathway regulates intestinal immunity and epithelial cell proliferation in humans, thus playing a role in colorectal cancer and inflammatory bowel disease. Our results suggest Jak/Stat is controlled by the circadian clock, which has implications for intestinal recovery following medical treatments, including radiation therapy. Funding Agencies NRC

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