Indigenous Arbuscular Mycorrhizal Fungi Associated with Acacia albida Del. in Different Areas of Senegal

The influences of seasons, plant age, and physicochemical properties of the soil on surface and deep biological arbuscular mycorrhizal fungus parameters associated with Acacia albida were assessed in different areas of Senegal. More indigenous arbuscular mycorrhizal propagules were found in the localities of the Sudano-Guinean zone (Djinaki and Kabrousse) than in those of the Sahelian zone (Louga and Diokoul), and species belonging to the genera Glomus, Gigaspora, Acaulospora, and Sclerocystis prevailed. The numbers of total and viable spores increased more during the rainy season than during the dry season (about 108% more total spores and 262% more viable spores). Similarly, both total and viable spores were more prevalent around young Acacia trees than old trees. However, the intensities of root colonization did not differ in each ecoclimatic zone.     

Genetic Diversity and Population Structure Analyses of Wild Relatives and Cultivated Cowpea (Vigna unguiculata (L.) Walp.) from Senegal Using Simple Sequence Repeat Markers

Cowpea (Vigna unguiculata (L.)) is an important crop for food security in Senegal; therefore, understanding the genetic diversity of local germplasm is relevant for crop improvement and genetic maintenance in the era of climate change. For this purpose, 15 microsatellite markers were used to estimate the genetic diversity of Senegalese cowpea germplasm, including 671 accessions grown in eight regions and 66 wild relatives and intermediate forms (weedy). For the cultivated, the main expected heterozygosity (mHe) ranged between 0.317 (Fatick) and 0.439 (South). A narrow genetic variation between accessions from the different regions was observed with genetic similarity ranging from 0.861 to 0.965 and genetic differentiation indices (Fst) between 0.018 and 0.100. The accessions from southern Senegal (Kédougou, Sédhiou, and Kolda regions) are more diverse than the others. However, the accessions from the North (Saint-Louis) are genetically different from other regions. The diversity analysis in wild relatives from Senegal, which had never been performed before, revealed that the wild/weedy forms remain more diverse than the cultivated with genetic diversity values (He) of 0.389 and 0.480, respectively. STRUCTURE software divided the Senegalese germplasm into five subpopulations. Three of them (i, ii, and iii) included only cultivated accessions from several regions, one (v) mainly from Saint-Louis, and one (iv) the wild/weedy with some cultivated accessions. Our results support the hypothesis that Vigna unguiculata var. spontanea is the wild progenitor of cowpea. The accessions from the South, the northern recession accessions, and the wild/weedy could serve as sources of new genes for the genetic improvement of cowpea in Senegal.

     

Community-directed distributors—The “foot soldiers” in the fight to control and eliminate neglected tropical diseases

The neglected tropical diseases (NTDs) affect hundreds of millions of people, predominantly in rural, often difficult-to-access areas, poorly served by national health services. Here, we review the contributions of 4.8 million community-directed distributors (CDDs) of medicines over 2 decades in 146,000 communities in 27 sub-Saharan African countries to control or eliminate onchocerciasis and lymphatic filariasis (LF). We examine their role in the control of other NTDs, malaria, HIV/AIDS interventions, immunisation campaigns, and support to overstretched health service personnel. We are of the opinion that CDDs as community selected, trained, and experienced “foot soldiers,” some of whom were involved in the Ebola outbreak responses at the community level in Liberia, if retrained, can assist community leaders and support health workers (HWs) in the ongoing Coronavirus Disease 2019 (COVID-19) crisis. The review highlights the improved treatment coverage where there are women CDDs, the benefits and lessons from the work of CDDs, their long-term engagement, and the challenges they face in healthcare delivery. It underscores the value of utilising the CDD model for strong community engagement and recommends the model, with some review, to hasten the achievement of the NTD 2030 goal and assist the health system cope with evolving epidemics and other challenges. We propose that, based on the unprecedented progress made in the control of NTDs directly linked to community engagement and contributions of CDDs “foot soldiers,” they deserve regional and global recognition. We also suggest that the World Health Organization (WHO) and other international stakeholders promote policy and guidance for countries to adapt this model for the elimination of NTDs and to strengthen national health services. This will enhance the accomplishment of some Sustainable Development Goals (SDGs) by 2030 in sub-Saharan Africa.     

Genetic and paleomodelling evidence of the population expansion of the cattle egret Bubulcus ibis in Africa during the climatic oscillations of the Late Pleistocene

Increasing aridity during glacial periods produced the retraction of forests and the expansion of arid and semi‐arid environments in Africa, with consequences for birds. Cattle egret Bubulcus ibis is a dispersive species that prefers semi‐arid environments and requires proximity to bodies of water. We expected that climatic oscillations led to the expansion of the range of the cattle egret during arid periods, such as the Last Maximum Glacial (LGM) and contraction of distribution during the Last Interglacial (LIG) period, resulting in contact of populations previously isolated. We investigated this hypothesis by evaluating the genetic structure and population history of 15 cattle egret breeding colonies located in west and South Africa using the mitochondrial DNA (mtDNA) control region, mtDNA ATPase 8 and 6, and an intron of nuclear gene transforming growth factor‐beta 2. Occurrence data and bioclimatic information were used to generate ecological niche models of three periods (present, LGM and LIG). We used the genetic and paleomodelling data to assess the responses of the cattle egret from Africa to the climatic oscillations during the late Pleistocene. Genetic data revealed low levels of genetic differentiation, signs of isolation‐by‐distance, as well as recent increases in effective population size that started during the LGM. The observed low genetic structure may be explained by recent colonization events due to the demographic expansion following the last glacial period and by dispersal capacity of this species. The paleomodels corroborated the expansion during the LGM, and a more restricted potential distribution during the LIG. Our findinds supports the hypothesis that the species range of the cattle egret expanded during arid periods and contracted during wet periods.     

Let‐7b‐5p inhibits proliferation and motility in squamous cell carcinoma cells through negative modulation of KIAA1377

KIAA1377 has been found to be linked with lymph node metastasis in esophageal squamous cell carcinoma (SCC) in our previous study; however, the regulation of KIAA1377 remains far from understood. Herein, to understand the regulation of KIAA1377 from the angle of microRNA (miRNA)–messenger RNA (mRNA) modulation in the setting of SCC cells, the basal level of KIAA1377 was determined by quantitative real‐time polymerase chain reaction (qRT‐PCR) and western blot analysis in KYSE‐150 and HeLa cells; biological roles of KIAA1377 contributing in the proliferation, migration, and invasion were evaluated using 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT), wound‐healing and Transwell assays, respectively, after KIAA1377 was knocked out mediated by the CRISPR‐Cas9 system. Bioinformatic prediction revealed that let‐7b‐5p was a putative miRNA regulating KIAA1377, which was ensuingly validated by the luciferase reporter assay; after which, variation of KIAA1377 expression was further verified by qRT‐PCR and western blot analysis. Moreover, the biological roles of let‐7b‐5p in proliferation, migration, and invasion of KYSE‐150 and HeLa cells were also evaluated. It was exhibited that KIAA1377 was able to promote the proliferation and motility of both KYSE‐150 and HeLa cells, which can be reverted by re‐expression of let‐7b‐5p. The luciferase reporter assay verified that let‐7b‐5p can diametrically target KIAA1377. Collectively, our data demonstrated that let‐7b‐5p can directly but negatively regulate KIAA1377 in SCC cell lines, Ecal109, and HeLa cells.     

Aminoglycosides and other factors promoting stop codon readthrough in human cells

Enhanced stop codon readthrough is a potential treatment strategy for diseases caused by nonsense mutations. Here, we compare readthrough levels induced by three types of factors: aminoglycoside antibiotics, suppressor tRNAs, and factors decreasing translation termination efficiency. We show that the highest levels of readthrough were obtained by prolonged treatment with aminoglycosides and suppressor tRNAs, whereas prolonged depletion of release factors induced only a moderate increase in readthrough. We discuss the benefits and inconvenients of the three types of factors for their use in the therapy of diseases caused by premature stop codons.     

郑州青台遗址新石器时代中晚期人群龋齿的统计与分析

本文通过对郑州青台遗址新石器时代中晚期91例个体、1913枚牙齿罹患龋齿的统计与分析可知,青台人群患龋率为71.43%,龋齿率为13.38%。其中,龋齿率女性高于男性,可能与女性孕期生理变化、食物选择及性别分工等有关。上颌龋齿率高于下颌,臼齿及咬合面为龋齿易患齿类及部位。通过对比可知青台人群显示出较高的龋齿罹患率,暗示该人群饮食中应包含较多的碳水化合物类食物,这可能与新石器时代中晚期黄河中游发达的旱作农业有关。此外,龋齿率在黄河及长江中、下游新石器时代农业人群中的区域性差异可能与龋病病因的复杂性和各地区不同的文化面貌、人群生活方式有关。