scholarly journals Three arenaviruses in three subspecific natal multimammate mouse taxa in Tanzania: same host specificity, but different spatial genetic structure?

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Laura N Cuypers ◽  
Stuart J E Baird ◽  
Alexandra Hánová ◽  
Tatjana Locus ◽  
Abdul S Katakweba ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
First Record ◽  
Sub Saharan Africa ◽  
Lassa Virus ◽  
Large Area ◽  
Order Of Magnitude ◽  
Morogoro Virus ◽  
Test Specificity ◽  
Sub Saharan

Abstract Mastomys natalensis is widespread in sub-Saharan Africa and hosts several arenavirus species, including the pathogenic zoonotic Lassa virus in West Africa. Mitochondrial lineages sub-divide the range of M. natalensis and have been associated with cryptic structure within the species. To test specificity of arenaviruses to hosts carrying these lineages, we screened 1772 M. natalensis in a large area of Tanzania where three mitochondrial lineages meet. We detected fifty-two individuals that were positive for one of three arenaviruses: Gairo, Morogoro, and Luna virus. This is the first record of Luna virus in Tanzania. We confirmed the specificity of each arenavirus to a distinct host mitochondrial lineage except for three cases in one locality at the centre of a host hybrid zone. No arenaviruses were detected in a large part of the study area. Morogoro and Gairo virus showed differences in prevalence (Morogoro virus lower than Gairo virus) and in genetic structure (Morogoro virus more structured than Gairo virus). However, both viruses have genetic neighbourhood size estimates of the same order of magnitude as Lassa virus. While differences in arenavirus and/or host evolutionary and ecological dynamics may exist, Tanzanian arenaviruses could be suited to model Lassa virus dynamics in M. natalensis.

scholarly journals Fine scale human genetic structure in three regions of Cameroon reveals episodic diversifying selection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kevin K. Esoh ◽  
Tobias O. Apinjoh ◽  
Steven G. Nyanjom ◽  
Ambroise Wonkam ◽  
Emile R. Chimusa ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Ethnic Groups ◽  
Genetic Association ◽  
Association Studies ◽  
Genetic Association Studies ◽  
Genomic Region ◽  
Sub Saharan Africa ◽  
Genome Wide Association Studies ◽  
Fine Scale ◽  
Sub Saharan

AbstractInferences from genetic association studies rely largely on the definition and description of the underlying populations that highlight their genetic similarities and differences. The clustering of human populations into subgroups (population structure) can significantly confound disease associations. This study investigated the fine-scale genetic structure within Cameroon that may underlie disparities observed with Cameroonian ethnicities in malaria genome-wide association studies in sub-Saharan Africa. Genotype data of 1073 individuals from three regions and three ethnic groups in Cameroon were analyzed using measures of genetic proximity to ascertain fine-scale genetic structure. Model-based clustering revealed distinct ancestral proportions among the Bantu, Semi-Bantu and Foulbe ethnic groups, while haplotype-based coancestry estimation revealed possible longstanding and ongoing sympatric differentiation among individuals of the Foulbe ethnic group, and their Bantu and Semi-Bantu counterparts. A genome scan found strong selection signatures in the HLA gene region, confirming longstanding knowledge of natural selection on this genomic region in African populations following immense disease pressure. Signatures of selection were also observed in the HBB gene cluster, a genomic region known to be under strong balancing selection in sub-Saharan Africa due to its co-evolution with malaria. This study further supports the role of evolution in shaping genomes of Cameroonian populations and reveals fine-scale hierarchical structure among and within Cameroonian ethnicities that may impact genetic association studies in the country.

Determinants of genetic structure of the Sub-Saharan parasitic wasp Cotesia sesamiae

2017 ◽  
Author(s):  
Antoine Branca ◽  
Bruno Le Ru ◽  
Paul-André Calatayud ◽  
Julius Obonyo ◽  
Boaz Muzyoka ◽  
...  
Keyword(s):  
Biological Control ◽  
Life History ◽  
Genetic Structure ◽  
Parasitic Wasp ◽  
Sub Saharan Africa ◽  
Host Specialization ◽  
Life History Strategies ◽  
Cotesia Sesamiae ◽  
Sub Saharan ◽  
Different Strains

AbstractParasitoid life style represents one of the most diversified life history strategies on earth. There are however very few studies on the variables associated with intraspecific diversity of parasitoid insects, especially regarding the relationship with spatial, biotic and abiotic ecological factors. Cotesia sesamiae is a Sub-Saharan stenophagous parasitic wasp that parasitizes several African stemborer species with variable developmental success. The different host-specialized populations are infected with different strains of Wolbachia, an endosymbiotic bacterium widespread in arthropods that is known for impacting life history traits notably reproduction, and consequently species distribution. In this study, first we analyzed the genetic structure of C. sesamiae across Sub-Saharan Africa, using 8 microsatellite markers, and 3 clustering software. We identified five major population clusters across Sub-Saharan Africa, which probably originated in East African Rift region and expanded throughout Africa in relation to host genus and abiotic factors such as climatic classifications. Using laboratory lines, we estimated the incompatibility between the different strains of Wolbachia infecting C. sesamiae. We observed an incompatibility between Wolbachia strains was asymmetric; expressed in one direction only. Based on these results, we assessed the relationships between direction of gene flow and Wolbachia infections in the genetic clusters. We found that Wolbachia-induced reproductive incompatibility was less influential than host specialization in the genetic structure. Both Wolbachia and host were more influential than geography and current climatic conditions. These results are discussed in the context of African biogeography, and co-evolution between Wolbachia, virus parasitoid and host, in the perspective of improving biological control efficiency through a better knowledge of the biodiversity of biological control agents.

High-resolution weather simulation for sub-Saharan Africa on the World Community Grid

2021 ◽  
Author(s):  
Camille Le Coz ◽  
Qidi Yu ◽  
Lloyd A. Treinish ◽  
Manuel Garcia Alvarez ◽  
Ashley Cryan ◽  
...  
Keyword(s):  
High Resolution ◽  
Wrf Model ◽  
Sub Saharan Africa ◽  
Large Area ◽  
World Community ◽  
The World ◽  
Sub Saharan ◽  
Socio Economic Impact ◽  
One Year ◽  
The Impact

<p>Rainfall in Africa is difficult to estimate accurately due to the large spatial variability. Most of the monsoon rainfall is generated by convective rainstorms that can be very localized, sometimes covering less than 100 km2. The goal of the African Rainfall Project is to run the Weather and Research Forecast (WRF) model for sub-Saharan Africa at a convection-permitting resolution in order to better represent such rainfall events. The resolution will be 1km, which is finer than most studies over Africa, which typically use resolutions of 3km or more. Running WRF for such a large area at such a high resolution is computationally expensive, which is where IBM’s World Community Grid comes in. The World Community Grid (WCG) is part of the Social Corporate Responsibility of IBM that crowdsources unused computing power from volunteers devices and donates it to scientific projects.</p><p>The simulation was adapted to the WCG by dividing the simulation of one year over sub-Saharan Africa in many smaller simulations of 48h over 52 by 52 km domains. These simulations are small enough to be calculated on a single computer of a volunteer at the required resolution. In total, 35609 overlapping domains are covering the whole of sub-Saharan Africa. During the post-processing phase, the smaller simulations are merged back together to obtain one consistent simulation over the whole continent.</p><p>Our main focus is rainfall, as this is the variable with the highest socio-economic impact in Africa. However, the outputs of the simulations include other variables such as the 2m-temperature, the 10m-wind speed and direction. These variables are outputted every 15min. At the end of this project, we will have over 3 billion files for a total of 0.5 PB. The data will be reorganized so that the different variables can be stored, searched and retrieved efficiently. After the reorganization, the data will be made publicly available.</p><p>The first validation step will be to examine the impact of dividing sub-Saharan Africa into many smaller domains. This will be done by comparing the simulation from this project to one large simulation. This simulation is obtained by running WRF at a 1km resolution on a large domain (500km by 1000km) for a shorter period, using Cartesius, the Dutch national computer. The second validation step will be to compare the simulations with satellite data and with in-situ measurements from the TAHMO network (www.tahmo.org).</p>

A new species of the palaearctic genus Dasypoda Latreille 1802 (Hymenoptera: Dasypodaidae) from the Great Rift Valley in Ethiopia

Zootaxa ◽  
2012 ◽  
Vol 3181 (1) ◽  
pp. 63
Author(s):  
DENIS MICHEZ ◽  
ALAIN PAULY
Keyword(s):  
New Species ◽  
Rift Valley ◽  
First Record ◽  
Solitary Bees ◽  
Sub Saharan Africa ◽  
Palaearctic Region ◽  
Sub Saharan ◽  
Great Rift Valley ◽  
A New Species

Dasypoda is a genus of solitary bees previously recorded as endemic in the Palaearctic region from Portugal to Japan. Wedescribe here a new species of Dasypoda (Hymenoptera, Apoidea, Melittidae), Dasypoda riftensis sp. nov., collected fromEthiopia, Great Rift Valley, Gallo. This species is the first record of the genus Dasypoda in Sub-Saharan Africa and is of phylogenetic importance. We discuss biogeographical implications of the record in Ethiopia.

scholarly journals Angolatitan adamastor, a new sauropod dinosaur and the first record from Angola

2011 ◽  
Vol 83 (1) ◽  
pp. 221-233 ◽  
Author(s):  
Octávio Mateus ◽  
Louis L. Jacobs ◽  
Anne S. Schulp ◽  
Michael J. Polcyn ◽  
Tatiana S. Tavares ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Late Cretaceous ◽  
First Record ◽  
Sub Saharan Africa ◽  
Sub Saharan

A forelimb of a new sauropod dinosaur (Angolatitan adamastor n. gen. et sp.) from the Late Turonian of Iembe (Bengo Province) represents the first dinosaur discovery in Angola, and is one of the few occurrences of sauropod dinosaurs in sub-Saharan Africa collected with good chronological controls. The marginal marine sediments yielding the specimen are reported to be late Turonian in age and, thus it represents a non-titanosaurian sauropod in sub-Saharan Africa at a time taken to be dominated by titanosaurian forms. Moreover, Angolatitan adamastor is the only basal Somphospondyli known in the Late Cretaceous which implies in the existence of relict forms in Africa.

scholarly journals Cyrtosathe gen. n.: the first non-scenopinine window fly from sub-Saharan Africa (Diptera: Scenopinidae)

Zootaxa ◽  
2005 ◽  
Vol 975 (1) ◽  
pp. 1 ◽  
Author(s):  
SHAUN L. WINTERTON ◽  
MARK A. METZ
Keyword(s):  
New Genus ◽  
First Record ◽  
Sub Saharan Africa ◽  
Phylogenetic Position ◽  
Intermediate Form ◽  
Monotypic Genus ◽  
Subsaharan Africa ◽  
Current Classification ◽  
Sub Saharan

An unusual new genus of Scenopinidae is described and figured from Namibia. Cyrtosathe kirkspriggsi gen. et sp. nov., represents the first record of a non-scenopinine window fly from subSaharan Africa. This monotypic genus does not fit well into the current classification of Scenopinidae and is likely an intermediate form between the subfamilies Proratinae and Scenopininae. The phylogenetic position of Cyrtosathe kirkspriggsi gen. et sp. nov. is discussed with respect to previous studies on Scenopinidae relationships and classification.

The first record of Astichus Förster (Hymenoptera: Eulophidae: Entiinae), parasitoids of Ciidae (Coleoptera) in bracket fungi, from the Afrotropical Region and the description of four new species from South Africa

Zootaxa ◽  
2012 ◽  
Vol 3183 (1) ◽  
pp. 49 ◽  
Author(s):  
OTTILIE C. NESER
Keyword(s):  
South Africa ◽  
New Species ◽  
South African ◽  
First Record ◽  
Sub Saharan Africa ◽  
Distribution Maps ◽  
Afrotropical Region ◽  
The World ◽  
Sub Saharan ◽  
First Time

The genus Astichus Förster (Eulophidae: Entiinae) is recorded for the first time from sub-Saharan Africa and four newspecies are described from South Africa: A. micans n. sp., A. silvani n. sp., A. gracilis n. sp. and A. naiadis n. sp. .Astichusspecies are known as parasitoids of Ciidae (Coleoptera) tunnelling and living in bracket fungi. The South African speciesemerged together with Ciidae from a variety of bracket fungi from many localities in the region. They are easily separatedfrom known Astichus species from other regions in the world by their distinctive colour and patterning. A key to the SouthAfrican Astichus species, distribution maps, and notes on biology are included, as well as identifications of Ciidae and bracket fungus specimens encountered in the study.

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