scholarly journals Insulators in Plants: Progress and Open Questions

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1422
Author(s):  
Amina Kurbidaeva ◽  
Michael Purugganan
Keyword(s):  
Future Research ◽  
Important Class ◽  
Cis Elements ◽  
Plant Genomes ◽  
Open Questions ◽  
Insulator Proteins ◽  
Topologically Associated Domains ◽  
Dna Elements ◽  
Mammalian Genomes ◽  
Higher Eukaryotes

The genomes of higher eukaryotes are partitioned into topologically associated domains or TADs, and insulators (also known as boundary elements) are the key elements responsible for their formation and maintenance. Insulators were first identified and extensively studied in Drosophila as well as mammalian genomes, and have also been described in yeast and plants. In addition, many insulator proteins are known in Drosophila, and some have been investigated in mammals. However, much less is known about this important class of non-coding DNA elements in plant genomes. In this review, we take a detailed look at known plant insulators across different species and provide an overview of potential determinants of plant insulator functions, including cis-elements and boundary proteins. We also discuss methods previously used in attempts to identify plant insulators, provide a perspective on their importance for research and biotechnology, and discuss areas of potential future research.

scholarly journals TADs pair homologous chromosomes to promote interchromosomal gene regulation

2018 ◽  
Author(s):  
Kayla Viets ◽  
Michael Sauria ◽  
Chaim Chernoff ◽  
Caitlin Anderson ◽  
Sang Tran ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Cell Types ◽  
Cell Type ◽  
Homologous Chromosomes ◽  
Molecular Features ◽  
Insulator Proteins ◽  
Topologically Associated Domains ◽  
Dna Elements ◽  
Cell Type Specific ◽  
Endogenous Loci

AbstractHomologous chromosomes colocalize to regulate gene expression in processes including genomic imprinting and X-inactivation, but the mechanisms driving these interactions are poorly understood. In Drosophila, homologous chromosomes pair throughout development, promoting an interchromosomal gene regulatory mechanism called transvection. Despite over a century of study, the molecular features that facilitate chromosome-wide pairing are unknown. The “button” model of pairing proposes that specific regions along chromosomes pair with a higher affinity than their surrounding regions, but only a handful of DNA elements that drive homologous pairing between chromosomes have been described. Here, we identify button loci interspersed across the fly genome that have the ability to pair with their homologous sequences. Buttons are characterized by topologically associated domains (TADs), which drive pairing with their endogenous loci from multiple locations in the genome. Fragments of TADs do not pair, suggesting a model in which combinations of elements interspersed along the full length of a TAD are required for pairing. Though DNA-binding insulator proteins are not associated with pairing, buttons are enriched for insulator cofactors, suggesting that these proteins may mediate higher order interactions between homologous TADs. Using a TAD spanning the spinelessd gene as a paradigm, we find that pairing is necessary but not sufficient for transvection. spineless pairing and transvection are cell-type-specific, suggesting that local buttoning and unbuttoning regulates transvection efficiency between cell types. Together, our data support a model in which specialized TADs button homologous chromosomes together to facilitate cell-type-specific interchromosomal gene regulation.

Further investigations on Fujimoto type strong uniqueness polynomials

Filomat ◽  
2017 ◽  
Vol 31 (16) ◽  
pp. 5203-5216
Author(s):  
Abhijit Banerjee ◽  
Bikash Chakraborty ◽  
Sanjay Mallick
Keyword(s):  
Meromorphic Functions ◽  
Future Research ◽  
Strong Uniqueness ◽  
Open Questions

Taking the question posed by the first author in [1] into background, we further exhaust-ably investigate existing Fujimoto type Strong Uniqueness Polynomial for Meromorphic functions (SUPM). We also introduce a new kind of SUPM named Restricted SUPM and exhibit some results which will give us a new direction to discuss the characteristics of a SUPM. Moreover, throughout the paper, we pose a number of open questions for future research.

scholarly journals Endocrine Disrupting Chemicals: Current Understanding, New Testing Strategies and Future Research Needs

2021 ◽  
Vol 22 (2) ◽  
pp. 933
Author(s):  
Maria E. Street ◽  
Karine Audouze ◽  
Juliette Legler ◽  
Hideko Sone ◽  
Paola Palanza
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Endocrine System ◽  
Current Understanding ◽  
Future Research ◽  
Developmental Origins ◽  
Research Needs ◽  
Important Class ◽  
Testing Strategies ◽  
Endocrine Disrupting ◽  
Health And Disease

Endocrine disrupting chemicals (EDCs) are exogenous chemicals which can disrupt any action of the endocrine system, and are an important class of substances which play a role in the Developmental Origins of Health and Disease (DOHaD) [...]

scholarly journals Hepatic stellate cells: current state and open questions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Claus Kordes ◽  
Hans H. Bock ◽  
Doreen Reichert ◽  
Petra May ◽  
Dieter Häussinger
Keyword(s):  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Essential Elements ◽  
Future Research ◽  
Heinrich Heine ◽  
Current State ◽  
Open Questions ◽  
Sinusoidal Endothelium ◽  
Cell Niche ◽  
Space Of Disse

Abstract This review article summarizes 20 years of our research on hepatic stellate cells within the framework of two collaborative research centers CRC575 and CRC974 at the Heinrich Heine University. Over this period, stellate cells were identified for the first time as mesenchymal stem cells of the liver, and important functions of these cells in the context of liver regeneration were discovered. Furthermore, it was determined that the space of Disse – bounded by the sinusoidal endothelium and hepatocytes – functions as a stem cell niche for stellate cells. Essential elements of this niche that control the maintenance of hepatic stellate cells have been identified alongside their impairment with age. This article aims to highlight previous studies on stellate cells and critically examine and identify open questions and future research directions.

The DEAH helicase DHX36 and its role in G-quadruplex-dependent processes

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Philipp Schult ◽  
Katrin Paeschke
Keyword(s):  
Current Knowledge ◽  
Future Research ◽  
Transcriptional Level ◽  
Cellular Functions ◽  
Multiple Functions ◽  
Open Questions ◽  
G Quadruplex ◽  
Cellular Pathways ◽  
Nucleic Acid Structures ◽  
Dependent Processes

AbstractDHX36 is a member of the DExD/H box helicase family, which comprises a large number of proteins involved in various cellular functions. Recently, the function of DHX36 in the regulation of G-quadruplexes (G4s) was demonstrated. G4s are alternative nucleic acid structures, which influence many cellular pathways on a transcriptional and post-transcriptional level. In this review we provide an overview of the current knowledge about DHX36 structure, substrate specificity, and mechanism of action based on the available models and crystal structures. Moreover, we outline its multiple functions in cellular homeostasis, immunity, and disease. Finally, we discuss the open questions and provide potential directions for future research.

Second language structural priming: A critical review and directions for future research

2017 ◽  
Vol 34 (4) ◽  
pp. 539-552 ◽  
Author(s):  
Carrie N. Jackson
Keyword(s):  
Second Language ◽  
Future Research ◽  
Structural Priming ◽  
Cognitive Mechanisms ◽  
L2 Acquisition ◽  
Current State ◽  
Current Review ◽  
Open Questions ◽  
Key Issues ◽  
State Of Research

The last 15 years has seen a tremendous growth in research on structural priming among second language (L2) speakers. Structural priming is the phenomenon whereby speakers are more likely to repeat a structure they have recently heard or produced. Research on L2 structural priming speaks to key issues regarding the underlying linguistic and cognitive mechanisms that support L2 acquisition and use, and the extent to which lexical and grammatical information are shared across an L2 speaker’s languages. As the number of researchers investigating L2 priming and its implications for L2 learning continues to grow, it is important to assess the current state of research in this area and establish directions for continued inquiry. The goal of the current review is to provide an overview of recent research on within-language L2 structural priming, with an eye towards the open questions that remain.

Retrospective: “culture shocks” in inter-cultural service encounters?

2016 ◽  
Vol 30 (4) ◽  
pp. 377-383 ◽  
Author(s):  
Bernd Stauss
Keyword(s):  
Marketing Research ◽  
Research Field ◽  
Scientific Development ◽  
Future Research ◽  
Service Encounters ◽  
Cultural Encounters ◽  
Content Type ◽  
Scientific Discussion ◽  
Open Questions ◽  
Cultural Service

Purpose The article “Culture shocks” in inter-cultural service encounters was published in 1999. The purpose of this paper is to analyze how the scientific discussion about this issue has developed and which open research questions are still awaiting solutions. Design/methodology/approach The main contributions of the original article are evaluated in the light of the current state of research. Simultaneously, the scientific development is commented on the basis of the original theoretical and empirical insights. Findings The original article belongs to those that initiated an extraordinary development of the research field. Aspects of inter-cultural encounters have found increasing attention in service marketing research. However, some fundamental problems of inter-cultural studies are still unresolved, and some of the theoretical and management oriented stimuli of the 1999 paper still seem worthy of consideration. Originality/value The retrospective analysis gives insight into the scientific development of the research on inter-cultural service encounters. It identifies relevant development lines, new perspectives and open questions for future research.

scholarly journals Arabis alpina: a perennial model plant for ecological genomics and life-history evolution

2021 ◽  
Author(s):  
Stefan Wötzel ◽  
Marco Andrello ◽  
Maria Albani ◽  
Marcus Koch ◽  
George Coupland ◽  
...  
Keyword(s):  
Life History ◽  
Life History Evolution ◽  
The Arctic ◽  
Model Organisms ◽  
Future Research ◽  
Ecological Genomics ◽  
Open Questions ◽  
Arabis Alpina ◽  
History Evolution ◽  
Plant Families

Many model organisms have obtained a prominent status due to an advantageous combination of their life-history characteristics, genetic properties and also practical considerations. In non-crop plants, Arabidopsis thaliana is the most renowned model and has been used as study system to elucidate numerous biological processes at the molecular level. Once a complete genome sequence was available, research has markedly accelerated and further established A. thaliana as the reference to stimulate studies in other species with different biology. Within the Brassicaceae family, the arctic-alpine perennial Arabis alpina has become a model complementary to A. thaliana to study life-history evolution and ecological genomics in harsh environments. In this review, we provide an overview of the properties that facilitated the rapid emergence of A. alpina as a plant model. We summarize the evolutionary history of A. alpina, including the diversification of its mating system, and discuss recent progress in the molecular dissection of developmental traits that are related to its perennial life history and environmental adaptation. We indicate open questions from which future research might be developed in other Brassicaceae species or more distantly related plant families.

scholarly journals Reducibility and Solvability of Some Classes of Kryuchkov Binary Tree Pairs

10.37236/2028 ◽  
2012 ◽  
Vol 18 (2) ◽  
Author(s):  
Maria Madonia ◽  
Giuseppe Scollo
Keyword(s):  
Induction Hypothesis ◽  
Binary Tree ◽  
Binary Trees ◽  
Equal Size ◽  
Future Research ◽  
Theoretic Approach ◽  
Research Directions ◽  
Open Questions ◽  
Future Research Directions

This paper addresses the problem of characterizing classes of pairs of binary trees of equal size for which a signed reassociation sequence, in the Eliahou-Kryuchkov sense, can be shown to exist, either with a size induction hypothesis (reducible pairs), or without it (solvable pairs). A few concepts proposed by Cooper, Rowland and Zeilberger, in the context of a language-theoretic approach to the problem, are here reformulated in terms of signed reassociation sequences, and some of their results are recasted and proven in this framework. A few strategies, tactics and combinations thereof for signed reassociation are introduced, which prove useful to extend the results obtained by the aforementioned authors to new classes of binary tree pairs. In particular, with reference to path trees, i.e. binary trees that have a leaf at every level, we show the reducibility of pairs where (at least) one of the two path trees has a triplication at the first turn below the top level, and we characterize a class of weakly mutually crooked path tree pairs that are neither reducible nor solvable by any previously known result, but prove solvable by appropriate reassociation strategies. This class also includes a subclass of mutually crooked path tree pairs. A summary evaluation of the achieved results, followed by an outline of open questions and future research directions conclude the paper.

scholarly journals Nurturing Grandchildren With Down Syndrome: A Qualitative Study on Grandparents’ Needs Using Digital Tools†

2021 ◽  
Vol 12 ◽  
Author(s):  
María C. Sánchez Gómez ◽  
Rocío Martín-Sevillano ◽  
María V. Martín-Cilleros ◽  
J. J. Mena Marcos ◽  
Francisco J. García-Peñalvo
Keyword(s):  
Down Syndrome ◽  
General Purpose ◽  
Future Research ◽  
Personal Perspective ◽  
Social Emotional ◽  
Individual Interviews ◽  
Open Questions ◽  
Future Research Directions ◽  
Qualitative Phenomenological ◽  
Negative Feelings

Grandparents who have grandchildren with disabilities are an underrepresented group in existing research related to the field. This qualitative phenomenological study’s general purpose is to analyze, from a personal perspective, the situations and needs of grandparents who have grandchildren with Down syndrome. The participants’ ages range from 65 to 85, and the ages of their grandchildren with Down syndrome range from 3 to 21 years. All participants had one grandchild with a disability, except for two, who each had two. A sociodemographic questionnaire was administered, and individual interviews were conducted, using open questions, through phone and/or video calls. An analysis of the participants’ speech was carried out, which implied the development of a system of meta-categories and categories. This analysis was developed manually, given the COVID-19 environment. The results indicate a substantial change from negative feelings caused by the knowledge of the diagnosis to feelings related to positive experiences expressed currently. The participants see themselves as a fundamental source of support (informal, instrumental, practical, social, emotional, and economic) for their families and, mainly, for their grandchildren with Down syndrome. A need for information and training was observed when the grandparents talked about first being informed of the diagnosis and their concerns about the future of these grandchildren and their siblings. They made social demands, such as greater government involvement or more significant opportunities to access resources and rights for their grandchildren. The results are discussed, as are possible future research directions.

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