scholarly journals Impact of transposable elements on the genome of the urban malaria vector Anopheles coluzzii

2020 ◽  
Author(s):  
Carlos Vargas-Chavez ◽  
Neil Michel Longo Pendy ◽  
Sandrine E. Nsango ◽  
Laura Aguilera ◽  
Diego Ayala ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Central Africa ◽  
Organic Pollution ◽  
Urban Environments ◽  
Sub Saharan Africa ◽  
Anopheles Coluzzii ◽  
The Impact

ABSTRACTBackgroundAnopheles coluzzii is one of the primary vectors of human malaria in sub-Saharan Africa. Recently, it has colonized the main cities of Central Africa threatening vector control programs. The adaptation of An. coluzzii to urban environments is partly due to an increased tolerance to organic pollution and insecticides. While some of the molecular mechanisms for ecological adaptation, including chromosome rearrangements and introgressions, are known, the role of transposable elements (TEs) in the adaptive processes of this species has not been studied yet.ResultsTo better understand the role of TEs in rapid urban adaptation, we sequenced using long-reads six An. coluzzii genomes from natural breeding sites in two major Central Africa cities. We de novo annotated the complete set of TEs and identified 64 previously undescribed families. TEs were non-randomly distributed throughout the genome with significant differences in the number of insertions of several superfamilies across the studied genomes. We identified seven putatively active families with insertions near genes with functions related to vectorial capacity. Moreover, we identified several TE insertions providing promoter and transcription factor binding sites to insecticide resistance and immune-related genes.ConclusionsThe analysis of multiple genomes sequenced using long-read technologies allowed us to generate the most comprehensive TE annotations in this species to date. We found that TEs have an impact in both the genome architecture and the regulation of functionally relevant genes in An. coluzzii. These results provide a basis for future studies of the impact of TEs on the biology of An. coluzzii.

Transposable element variants and their potential adaptive impact in urban populations of the malaria vector Anopheles coluzzii

2021 ◽  
Author(s):  
Carlos Vargas-Chavez ◽  
Neil Michel Longo Pendy ◽  
Sandrine E. Nsango ◽  
Laura Aguilera ◽  
Diego Ayala ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
De Novo ◽  
Central Africa ◽  
Organic Pollution ◽  
Urban Environments ◽  
Sub Saharan Africa ◽  
Anopheles Coluzzii ◽  
High Quality ◽  
The Impact

Anophelescoluzzii is one of the primary vectors of human malaria in sub-Saharan Africa. Recently, it has spread into the main cities of Central Africa threatening vector control programs. The adaptation of An. coluzzii to urban environments partly results from an increased tolerance to organic pollution and insecticides. Some of the molecular mechanisms for ecological adaptation are known, but the role of transposable elements (TEs) in the adaptive processes of this species has not been studied yet. As a first step toward assessing the role of TEs in rapid urban adaptation, we sequenced using long reads six An. coluzzii genomes from natural breeding sites in two major Central Africa cities. We de novo annotated TEs in these genomes and in an additional high-quality An. coluzzii genome, and we identified 64 new TE families. TEs were nonrandomly distributed throughout the genome with significant differences in the number of insertions of several superfamilies across the studied genomes. We identified seven putatively active families with insertions near genes with functions related to vectorial capacity, and several TEs that may provide promoter and transcription factor binding sites to insecticide resistance and immune-related genes. Overall, the analysis of multiple high-quality genomes allowed us to generate the most comprehensive TE annotation in this species to date and identify several TE insertions that could potentially impact both genome architecture and the regulation of functionally relevant genes. These results provide a basis for future studies of the impact of TEs on the biology of An. coluzzii.

The impact of Traditional Chinese Medicine on mitophagy in disease models

2021 ◽  
Vol 27 ◽  
Author(s):  
Li-Ping Yu ◽  
Ting-Ting Shi ◽  
Yan-Qin Li ◽  
Jian-Kang Mu ◽  
Ya-Qin Yang ◽  
...  
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Molecular Mechanisms ◽  
Human Diseases ◽  
Regulatory Mechanisms ◽  
Disease Models ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

: Mitophagy plays an important role in maintaining mitochondrial quality and cell homeostasis through the degradation of damaged, aged, and dysfunctional mitochondria and misfolded proteins. Many human diseases, particularly neurodegenerative diseases, are related to disorders of mitochondrial phagocytosis. Exploring the regulatory mechanisms of mitophagy is of great significance for revealing the molecular mechanisms underlying the related diseases. Herein, we summarize the major mechanisms of mitophagy, the relationship of mitophagy with human diseases, and the role of traditional Chinese medicine (TCM) in mitophagy. These discussions enhance our knowledge of mitophagy and its potential therapeutic targets using TCM.

Self-Reported Vision Impairment and Frailty among Older People with Low Cognitive Performance in Central Africa: EPIDEMCA Population-Based Study

2021 ◽  
pp. 1-7
Author(s):  
Antoine Gbessemehlan ◽  
Gilles Kehoua ◽  
Catherine Helmer ◽  
Cécile Delcourt ◽  
Achille Tchalla ◽  
...  
Keyword(s):  
Older People ◽  
Cognitive Performance ◽  
Odds Ratio ◽  
Adjusted Odds Ratio ◽  
Central Africa ◽  
Population Based ◽  
Vision Impairment ◽  
Sub Saharan Africa ◽  
Population Based Study ◽  
The Impact

<b><i>Introduction:</i></b> Very little is known about the impact of vision impairment (VI) on physical health in late-life in sub-Saharan Africa populations, whereas many older people experience it. We investigated the association between self-reported VI and frailty in Central African older people with low cognitive performance. <b><i>Methods:</i></b> It was cross-sectional analysis of data from the Epidemiology of Dementia in Central Africa (EPIDEMCA) population-based study. After screening for cognitive impairment, older people with low cognitive performance were selected. Frailty was assessed using the Study of Osteoporotic Fracture index. Participants who met one of the 3 parameters assessed (unintentional weight loss, inability to do 5 chair stands, and low energy level) were considered as pre-frail, and those who met 2 or more parameters were considered as frail. VI was self-reported. Associations were investigated using multinomial logistic regression models. <b><i>Results:</i></b> Out of 2,002 older people enrolled in EPIDEMCA, 775 (38.7%) had low cognitive performance on the screening test. Of them, 514 participants (sex ratio: 0.25) had available data on VI and frailty and were included in the analyses. In total, 360 (70%) self-reported VI. Prevalence of frailty was estimated at 64.9% [95% confidence interval: 60.9%–69.1%] and 23.7% [95% CI: 20.1%–27.4%] for pre-frailty. After full adjustment, self-reported VI was associated with frailty (adjusted odds ratio = 2.2; 95% CI: 1.1–4.3) but not with pre-frailty (adjusted odds ratio = 1.8; 95% CI: 0.9–3.7). <b><i>Conclusion:</i></b> In Central African older people with low cognitive performance, those who self-reported VI were more likely to experience frailty. Our findings suggest that greater attention should be devoted to VI among this vulnerable population in order to identify early frailty onset and provide adequate care management.

scholarly journals The Genomic Ecosystem of Transposable Elements in Maize

2019 ◽  
Author(s):  
Michelle C. Stitzer ◽  
Sarah N. Anderson ◽  
Nathan M. Springer ◽  
Jeffrey Ross-Ibarra
Keyword(s):  
Transposable Elements ◽  
Evolutionary Dynamics ◽  
Phenotypic Diversity ◽  
Flowering Plant ◽  
Genome Wide ◽  
Family Level ◽  
Genomic Environment ◽  
Single Category ◽  
The Impact

Transposable elements (TEs) constitute the majority of flowering plant DNA, reflecting their tremendous success in subverting, avoiding, and surviving the defenses of their host genomes to ensure their selfish replication. More than 85% of the sequence of the maize genome can be ascribed to past transposition, providing a major contribution to the structure of the genome. Evidence from individual loci has informed our understanding of how transposition has shaped the genome, and a number of individual TE insertions have been causally linked to dramatic phenotypic changes. But genome-wide analyses in maize and other taxa have frequently represented TEs as a relatively homogeneous class of fragmentary relics of past transposition, obscuring their evolutionary history and interaction with their host genome. Using an updated annotation of structurally intact TEs in the maize reference genome, we investigate the family-level ecological and evolutionary dynamics of TEs in maize. Integrating a variety of data, from descriptors of individual TEs like coding capacity, expression, and methylation, as well as similar features of the sequence they inserted into, we model the relationship between these attributes of the genomic environment and the survival of TE copies and families. Our analyses reveal a diversity of ecological strategies of TE families, each representing the evolution of a distinct ecological niche allowing survival of the TE family. In contrast to the wholesale relegation of all TEs to a single category of junk DNA, these differences generate a rich ecology of the genome, suggesting families of TEs that coexist in time and space compete and cooperate with each other. We conclude that while the impact of transposition is highly family- and context-dependent, a family-level understanding of the ecology of TEs in the genome can refine our ability to predict the role of TEs in generating genetic and phenotypic diversity.‘Lumping our beautiful collection of transposons into a single category is a crime’-Michael R. Freeling, Mar. 10, 2017

China’s Economic Expansion in Sub-Saharan Africa

2018 ◽  
pp. 113-148
Author(s):  
Rhys Jenkins
Keyword(s):  
Foreign Direct Investment ◽  
Direct Investment ◽  
Sub Saharan Africa ◽  
Economic Expansion ◽  
Economic Relations ◽  
Different Types ◽  
Sub Saharan ◽  
The Impact ◽  
Engineering Projects

The chapter documents the growth of economic relations between China and Sub-Saharan Africa (SSA), focussing on trade, foreign direct investment, Chinese construction and engineering projects, loans, and aid. The chapter highlights the way in which these are sometimes combined in resources-for-infrastructure deals. It shows the variety of different actors involved in these relationships, including state and non-state actors, on both the Chinese and African sides. It then discusses the role of strategic diplomatic, strategic economic, and commercial objectives in the growing Chinese involvement in SSA. It also addresses questions of African agency and the interests of African actors in economic relations with China. The impact of political, strategic economic and commercial factors on different types of economic relations is then analyzed econometrically.

scholarly journals Transit Migration in Niger

2020 ◽  
Vol 3 (1) ◽  
pp. 80-88
Author(s):  
Sébastien Moretti
Keyword(s):  
Local Level ◽  
Sub Saharan Africa ◽  
The European Union ◽  
Migration Policies ◽  
Transit Migration ◽  
Migratory Routes ◽  
Sub Saharan ◽  
Restrictive Measures ◽  
The Impact

Since 2015, the European Union has stepped up its efforts to curb irregular migration from sub-Saharan Africa through increasingly restrictive measures targeting transit countries along migratory routes, including Niger. While the EU has heralded the success of its policies to limit migration through Niger, EU migration policies have disrupted the economic system in Agadez, where transit migration has been one of the main sources of income and a factor of stability since the end of the Tuareg rebellions in 2009. This article discusses the impact that EU migration policies may have at the local level in countries of transit, and highlights the potential for these policies to fuel tensions between local and national authorities. The Agadez case study illustrates the importance of a multilevel approach to migration governance that takes into full consideration the role of local authorities and local communities in countries of transit.

scholarly journals The Role of Dysfunctional Adipose Tissue in Pancreatic Cancer: A Molecular Perspective

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1849 ◽  
Author(s):  
Davide Brocco ◽  
Rosalba Florio ◽  
Laura De Lellis ◽  
Serena Veschi ◽  
Antonino Grassadonia ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Adipose Tissue ◽  
Molecular Mechanisms ◽  
Normal Weight ◽  
Therapeutic Options ◽  
Therapeutic Interventions ◽  
Fat Accumulation ◽  
Adipose Organ ◽  
The Impact

Pancreatic cancer (PC) is a lethal malignancy with rising incidence and limited therapeutic options. Obesity is a well-established risk factor for PC development. Moreover, it negatively affects outcome in PC patients. Excessive fat accumulation in obese, over- and normal-weight individuals induces metabolic and inflammatory changes of adipose tissue microenvironment leading to a dysfunctional adipose “organ”. This may drive the association between abnormal fat accumulation and pancreatic cancer. In this review, we describe several molecular mechanisms that underpin this association at both local and systemic levels. We focus on the role of adipose tissue-derived circulating factors including adipokines, hormones and pro-inflammatory cytokines, as well as on the impact of the local adipose tissue in promoting PC. A discussion on potential therapeutic interventions, interfering with pro-tumorigenic effects of dysfunctional adipose tissue in PC, is included. Considering the raise of global obesity, research efforts to uncover the molecular basis of the relationship between pancreatic cancer and adipose tissue dysfunction may provide novel insights for the prevention of this deadly disease. In addition, these efforts may uncover novel targets for personalized interventional strategies aimed at improving the currently unsatisfactory PC therapeutic options.

scholarly journals Contribution of retrotransposition to developmental disorders

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Eugene J. Gardner ◽  
Elena Prigmore ◽  
Giuseppe Gallone ◽  
Petr Danecek ◽  
Kaitlin E. Samocha ◽  
...  
Keyword(s):  
Developmental Disorders ◽  
De Novo ◽  
Purifying Selection ◽  
Selective Constraint ◽  
Protein Coding ◽  
Genome Wide ◽  
De Novo Gene ◽  
The Impact ◽  
Transcribed Sequences

Abstract Mobile genetic Elements (MEs) are segments of DNA which can copy themselves and other transcribed sequences through the process of retrotransposition (RT). In humans several disorders have been attributed to RT, but the role of RT in severe developmental disorders (DD) has not yet been explored. Here we identify RT-derived events in 9738 exome sequenced trios with DD-affected probands. We ascertain 9 de novo MEs, 4 of which are likely causative of the patient’s symptoms (0.04%), as well as 2 de novo gene retroduplications. Beyond identifying likely diagnostic RT events, we estimate genome-wide germline ME mutation rate and selective constraint and demonstrate that coding RT events have signatures of purifying selection equivalent to those of truncating mutations. Overall, our analysis represents a comprehensive interrogation of the impact of retrotransposition on protein coding genes and a framework for future evolutionary and disease studies.

EFFECTS OF COUPLES' CHARACTERISTICS ON CONTRACEPTIVE USE IN SUB-SAHARAN AFRICA: THE GHANAIAN EXAMPLE

1997 ◽  
Vol 29 (1) ◽  
pp. 33-49 ◽  
Author(s):  
YAW OHENEBA-SAKYI ◽  
BAFFOUR K. TAKYI
Keyword(s):  
Family Planning ◽  
Health Survey ◽  
Contraceptive Use ◽  
Sub Saharan Africa ◽  
Men And Women ◽  
Socioeconomic Characteristics ◽  
Sub Saharan ◽  
Using Data ◽  
The Impact

Using data from the 1988 Ghana Demographic and Health Survey, this study examines couples' demographic and socioeconomic characteristics in the context of their attitudes towards family planning, and the impact of these factors on the use of contraceptives. The characteristics of the husbands and their influence on wives' behaviour illustrate the role of intra-household relations between men and women and their effect on fertility-related behaviour in patriarchal African societies.

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