scholarly journals Sequestration to lipid droplets promotes histone availability by preventing turnover of excess histones

Development ◽  
2021 ◽  
Author(s):  
Roxan A. Stephenson ◽  
Jonathon M. Thomalla ◽  
Lili Chen ◽  
Petra Kolkhof ◽  
Roger P. White ◽  
...  
Keyword(s):  
Lipid Droplets ◽  
Quantitative Imaging ◽  
Nurse Cells ◽  
Intercellular Transport ◽  
Drosophila Oogenesis ◽  
Tightly Coupled ◽  
Histone Synthesis ◽  
Insight Into ◽  
Shed Light ◽  
Drosophila Embryos

Because both dearth and overabundance of histones result in cellular defects, histone synthesis and demand are typically tightly coupled. In Drosophila embryos, histones H2B/H2A/H2Av accumulate on lipid droplets (LDs), cytoplasmic fat storage organelles. Without LD-binding, maternally provided H2B/H2A/H2Av are absent, but how LDs ensure histone storage is unclear. Using quantitative imaging, we uncover when during oogenesis these histones accumulate, and which step of accumulation is LD-dependent. LDs originate in nurse cells (NCs) and are transported to the oocyte. Although H2Av accumulates on LDs in NCs, the majority of the final H2Av pool is synthesized in oocytes. LDs promote intercellular transport of the histone-anchor Jabba and thus its presence in the ooplasm. Ooplasmic Jabba then prevents H2Av degradation, safeguarding the H2Av stockpile. Our findings provide insight into the mechanism for establishing histone stores during Drosophila oogenesis and shed light on the function of LDs as protein-sequestration sites.

scholarly journals Sequestration to lipid droplets promotes histone availability by preventing turnover of excess histones

2020 ◽  
Author(s):  
Roxan A. Stephenson ◽  
Jonathon M. Thomalla ◽  
Lili Chen ◽  
Petra Kolkhof ◽  
Mathias Beller ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Lipid Droplets ◽  
Quantitative Imaging ◽  
Nurse Cells ◽  
Intercellular Transport ◽  
Fat Storage ◽  
Tightly Coupled ◽  
Histone Synthesis ◽  
Insight Into ◽  
Shed Light

AbstractBecause dearth and overabundance of histones result in cellular defects, histone synthesis and demand are typically tightly coupled. In Drosophila embryos, histones H2B/H2A/H2Av accumulate on lipid droplets (LDs), cytoplasmic fat storage organelles. Without this binding, maternally provided H2B/H2A/H2Av are absent; however, the molecular basis of how LDs ensure histone storage is unclear. Using quantitative imaging, we uncover when during oogenesis these histones accumulate, and which step of accumulation is LD-dependent. LDs originate in nurse cells and are transported to the oocyte. Although H2Av accumulates on LDs in nurse cells, the majority of the final H2Av pool is synthesized in oocytes. LDs promote intercellular transport of the histone-anchor Jabba and thus its presence in the ooplasm. Jabba prevents ooplasmic H2Av from degradation, safeguarding the H2Av stockpile. Our findings provide insight into the mechanism for establishing histone stores during Drosophila oogenesis and shed light on the function of LDs as protein-sequestration sites.

Reorganization of the cytoskeleton during Drosophila oogenesis: implications for axis specification and intercellular transport

Development ◽  
1992 ◽  
Vol 115 (4) ◽  
pp. 923-936 ◽  
Author(s):  
W.E. Theurkauf ◽  
S. Smiley ◽  
M.L. Wong ◽  
B.M. Alberts
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Nurse Cells ◽  
Intercellular Transport ◽  
Drosophila Oogenesis ◽  
Actin Organization ◽  
Scanning Confocal Microscopy ◽  
Cytoplasmic Bridges ◽  
Fluorescence Cytochemistry ◽  
Pass Through

Inhibitor studies have implicated microtubules in at least three important developmental processes during Drosophila oogenesis: oocyte determination and growth during stages 1 through 6, positioning of the anterior determinant bicoid mRNA during stages 9 through 12, and ooplasmic streaming during stages 10b through 12. We have used fluorescence cytochemistry together with laser scanning confocal microscopy to identify distinct microtubule structures at each of the above three periods that are likely to be involved in these processes. During stages 1 through 7, maternal components synthesized in nurse cells are transported through cytoplasmic bridges to the oocyte. At this time, microtubules that appear to originate in the oocyte pass through these cytoplasmic bridges into the adjacent nurse cells; these microtubules are likely to serve as a polarized scaffold on which maternal RNAs and proteins are transported. During stages 7 and 8, microtubules in the oocyte cortex reorganize to form an anterior-to-posterior gradient, suggesting a role for microtubules in the localization of morphogenetic determinants. Finally, when ooplasmic streaming begins during stage 10 b, it is accompanied by the assembly of subsurface microtubule arrays that spiral around the oocyte; these arrays disassemble as the oocyte matures and streaming stops. During ooplasmic streaming, many vesicles are closely associated with the subsurface microtubules, suggesting that streaming is driven by vesicle translocation along microtubules. We believe that actin plays a secondary role in each of these morphogenetic events, based on our parallel studies of actin organization during each of the above stages of oogenesis.

Sentence-Based Experience Logging in New Hearing Aid Users

2020 ◽  
Vol 29 (3S) ◽  
pp. 631-637
Author(s):  
Katja Lund ◽  
Rodrigo Ordoñez ◽  
Jens Bo Nielsen ◽  
Dorte Hammershøi
Keyword(s):  
Hearing Aid ◽  
Patient Experiences ◽  
Online Tool ◽  
Rehabilitation Process ◽  
Hearing Rehabilitation ◽  
Clinical Observations ◽  
Hearing Aid Use ◽  
Wide Range ◽  
Insight Into ◽  
Shed Light

Purpose The aim of this study was to develop a tool to gain insight into the daily experiences of new hearing aid users and to shed light on aspects of aided performance that may not be unveiled through standard questionnaires. Method The tool is developed based on clinical observations, patient experiences, expert involvement, and existing validated hearing rehabilitation questionnaires. Results An online tool for collecting data related to hearing aid use was developed. The tool is based on 453 prefabricated sentences representing experiences within 13 categories related to hearing aid use. Conclusions The tool has the potential to reflect a wide range of individual experiences with hearing aid use, including auditory and nonauditory aspects. These experiences may hold important knowledge for both the patient and the professional in the hearing rehabilitation process.

Aleksey Peshkov as an editor of Samarskaya Gazeta

2020 ◽  
pp. 128-138
Author(s):  
A. S. Bik-Bulatov
Keyword(s):  
Local History ◽  
Organizational Skills ◽  
First Time ◽  
New Evidence ◽  
Insight Into ◽  
Shed Light

The article uses little known letters of M. Gorky, many of which were published for the first time in 1997, as well as findings of Samara-based experts in local history to shed light on the writer’s work as editor-in-chief of the Samarskaya Gazeta newspaper in 1895. The researcher introduces hitherto unstudied reminiscences of the journalist D. Linyov (Dalin) about this period, which reference a letter by Gorky, now lost. The paper details a newly discovered episode of Gorky’s professional biography as a journalist: it concerns his campaign against a Samara ‘she-wolf,’ the madam of a local brothel A. Neucheva. Linyov’s reminiscences turn out to be an important and interesting source, offering an insight into the daily grind of the young editor Gorky, providing new evidence of his excellent organizational skills, and describing his moral and social stance. The author presents his work in the context of a recently initiated broader discussion about the need to map out all Russian periodicals for the period until 1917, as well as all research devoted to individual publications.

scholarly journals Revisiting an Aspergillus flavus Strain Isolated from an Egyptian Sugarcane Field in 1930

2020 ◽  
Vol 8 (11) ◽  
pp. 1633
Author(s):  
Mohamed F. Abdallah ◽  
Kris Audenaert ◽  
Sarah De Saeger ◽  
Jos Houbraken
Keyword(s):  
Aspergillus Flavus ◽  
Short Communication ◽  
Aflatoxin Contamination ◽  
Type B ◽  
Prevention Strategies ◽  
Sugarcane Field ◽  
Host Pathogen Interaction ◽  
Sugarcane Crop ◽  
Insight Into ◽  
Shed Light

The aflatoxin type B and G producer Aspergillus novoparasiticus was described in 2012 and was firstly reported from sputum, hospital air (Brazil), and soil (Colombia). Later, several survey studies reported the occurrence of this species in different foods and other agricultural commodities from several countries worldwide. This short communication reports on an old fungal strain (CBS 108.30), isolated from Pseudococcus sacchari (grey sugarcane mealybug) from an Egyptian sugarcane field in (or before) 1930. This strain was initially identified as Aspergillus flavus; however, using the latest taxonomy schemes, the strain is, in fact, A. novoparasiticus. These data and previous reports indicate that A. novoparasiticus is strongly associated with sugarcane, and pre-harvest biocontrol approaches with non-toxigenic A. novoparasiticus strains are likely to be more successful than those using non-toxigenic A. flavus strains. Further studies on the association between A. novoparasiticus and Pseudococcus sacchari might shed light on the distribution (and aflatoxin contamination) of this species in sugarcane. Additionally, the interaction between A. novoparasiticus, Pseudococcus sacchari, and sugarcane crop under different scenarios of climate change will be critical in order to get more insight into the host–pathogen interaction and host resistance and propose appropriate prevention strategies to decrease mycotoxin contamination and crop loss due to A. novoparasiticus attack.

Posthumous baggage. Harper Lee’s letters

2021 ◽  
pp. 194-214
Author(s):  
D. V. Zakharov
Keyword(s):  
Personal Life ◽  
Private Correspondence ◽  
To Kill A Mockingbird ◽  
Detailed List ◽  
Harper Lee ◽  
Insight Into ◽  
Shed Light

The article is devoted to the epistolary legacy of Nelle Harper Lee, the author of the American cult classic To Kill a Mockingbird (1960). The researcher examines a collection of Nelle’s letters written from 1956 to 2009, provides a detailed list of sources and makes suggestions about the potential new discoveries that could shed light on the life of ‘America’s most reclusive author.’ This short study of ‘posthumous baggage,’ as Lee referred to her private correspondence, offers an insight into the interests of the author, who insisted on keeping her personal life to herself. The letters included in the study concern the writer’s relationship to her father Amasa Coleman Lee, on whom she based the character of Atticus Finch, her attitude to her own biography published by Charles Shields, and personal anxieties of her final years. The author also details Lee’s opinions of literature, from the 19th-c. classics to contemporary authors, and shows how much she valued communication with her numerous fans.

Black-white mixed race young people in Ireland and their lived experiences of racialised exclusion

2021 ◽  
pp. 079160352110684
Author(s):  
Patti O’Malley
Keyword(s):  
Young People ◽  
Mixed Race ◽  
Regular Feature ◽  
Black African ◽  
Academic Scholarship ◽  
Irish Context ◽  
Irish Identity ◽  
Depth Interviews ◽  
Insight Into ◽  
Shed Light

The multiracial family and the existence of mixed race children have come to be a regular feature of Irish familial life. Yet, nation-building discourses have promulgated notions of ethnic and religious homogeneity with Irish identity being racialised exclusively as white. Moreover, to date, there has been a dearth of academic scholarship related to racial mixedness in the Irish context. Through in-depth interviews, this paper sets out, therefore, to provide empirical insight into the lives of fifteen black (African) – white (Irish) mixed race young people (aged 4 to 18) with a particular focus on their experiences of racialised exclusion. Indeed, findings suggest that, as in other majority white national contexts, the black-white mixed race young people are racialised as black in the Irish public domain and as such, are positioned as ‘racialised outsiders’. In fact, their narrative accounts shed light on everyday encounters saturated by ‘us-them’ racial constructs based on phenotype. Thus, these young people, who are not fully recognised as mixed race Irish citizens, are effectively deprived of a space in which to articulate their belonging within the existing statist (i.e. inside/outside) framework.

scholarly journals The Communication of Ideas across Subfields in Political Science

2014 ◽  
Vol 47 (02) ◽  
pp. 468-476 ◽  
Author(s):  
Erin R. Graham ◽  
Charles R. Shipan ◽  
Craig Volden
Keyword(s):  
Network Analysis ◽  
International Relations ◽  
Political Science ◽  
Comparative Politics ◽  
Diffusion Processes ◽  
Methodological Approach ◽  
Journal Articles ◽  
Insight Into ◽  
Shed Light ◽  
Levels Of Integration

ABSTRACTWhat factors inhibit or facilitate cross-subfield conversations in political science? This article draws on diffusion scholarship to gain insight into cross-subfield communication. Diffusion scholarship represents a case where such communication might be expected, given that similar diffusion processes are analyzed in American politics, comparative politics, and international relations. We identify nearly 800 journal articles published on diffusion within political science between 1958 and 2008. Using network analysis we investigate the degree to which three “common culprits”—terminology, methodological approach, and journal type—influence levels of integration. We find the highest levels of integration among scholars using similar terms to describe diffusion processes, sharing a methodological approach (especially in quantitative scholarship), and publishing in a common set of subfield journals. These findings shed light on when cross-subfield communication is likely to occur with ease and when barriers may prove prohibitive.

scholarly journals The Value of Abstraction

2019 ◽  
Author(s):  
Mark K Ho ◽  
David Abel ◽  
Tom Griffiths ◽  
Michael L. Littman
Keyword(s):  
Problem Solving ◽  
Relevant Information ◽  
Scaling Up ◽  
Limited Resources ◽  
Abstract Representations ◽  
Learning Research ◽  
Crucial Ingredient ◽  
Insight Into ◽  
Shed Light

Agents that can make better use of computation, experience, time, and memory can solve a greater range of problems more effectively. A crucial ingredient for managing such finite resources is intelligently chosen abstract representations. But, how do abstractions facilitate problem solving under limited resources? What makes an abstraction useful? To answer such questions, we review several trends in recent reinforcement-learning research that provide insight into how abstractions interact with learning and decision making. During learning, abstraction can guide exploration and generalization as well as facilitate efficient tradeoffs---e.g., time spent learning versus the quality of a solution. During computation, good abstractions provide simplified models for computation while also preserving relevant information about decision-theoretic quantities. These features of abstraction are not only key for scaling up artificial problem solving, but can also shed light on what pressures shape the use of abstract representations in humans and other organisms.

scholarly journals Converging physiological roles of the anthrax toxin receptors

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1415
Author(s):  
Oksana A. Sergeeva ◽  
F. Gisou van der Goot
Keyword(s):  
Anthrax Toxin ◽  
Loss Of Function ◽  
Disease Symptoms ◽  
Hyaline Fibromatosis Syndrome ◽  
Anthrax Toxins ◽  
The Difference ◽  
Related Proteins ◽  
Tumor Endothelial Marker 8 ◽  
Insight Into ◽  
Shed Light

The anthrax toxin receptors—capillary morphogenesis gene 2 (CMG2) and tumor endothelial marker 8 (TEM8)—were identified almost 20 years ago, although few studies have moved beyond their roles as receptors for the anthrax toxins to address their physiological functions. In the last few years, insight into their endogenous roles has come from two rare diseases: hyaline fibromatosis syndrome, caused by mutations in CMG2, and growth retardation, alopecia, pseudo-anodontia, and optic atrophy (GAPO) syndrome, caused by loss-of-function mutations in TEM8. Although CMG2 and TEM8 are highly homologous at the protein level, the difference in disease symptoms points to variations in the physiological roles of the two anthrax receptors. Here, we focus on the similarities between these receptors in their ability to regulate extracellular matrix homeostasis, angiogenesis, cell migration, and skin elasticity. In this way, we shed light on how mutations in these two related proteins cause such seemingly different diseases and we highlight the existing knowledge gaps that could form the focus of future studies.

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