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Biology subjects

Keita, M.

Publications and source records attributed to Keita, M..

3 recordsLinked to original sources

SARS-CoV-2 in the Republic of Guinea: Fragment and Whole-Genome Sequencing, Phylogenetic Analysis

Genetic diversity of SARS-CoV-2 isolates circulating in the Republic of Guinea in May and June 2020, as well as in March 2021, has been demonstrated using fragment (S gene) and whole genome sequencing of 14 strains. Analysis of nucleotide sequences and phylogenetic constructs make it possible to divide the studied strains into 3 groups. Comparison of the obtained data with the already available epidemiological data proves the initial importation of COVID-19 from Western European countries, and also demonstrates four independent import routes in two time periods (March 2020 and no later than March 2021).

microbiology↗

High-throughput Identification of Eukaryotic Parasites and Arboviruses in Mosquitoes

Vector-borne pathogens cause many human infectious diseases and are responsible for high mortality and morbidity throughout the world. They can also cause livestock epidemics with dramatic social and economic consequences. Due to the high costs, vector-borne disease surveillance is often limited to current threats, and the investigation of emerging pathogens typically occur after the reports of clinical cases. Here, we use high-throughput sequencing to detect and identify a wide range of parasites and viruses carried by mosquitoes from Cambodia, Guinea, Mali and Maryland. We apply this approach to individual Anopheles mosquitoes as well as pools of mosquitoes captured in traps; and compare the outcomes of this assay when applied to DNA or RNA. We identified known human and animal pathogens and mosquito parasites belonging to a wide range of taxa, insect Flaviviruses, and novel DNA sequences from previously uncharacterized organisms. Our results also revealed that analysis of the content of an entire trap is an efficient approach to monitor and identify potential vector-borne pathogens in large surveillance studies, and that analyses of RNA extracted from mosquitoes is preferable, when possible, over DNA-based analyses. Overall, we describe a flexible and easy-to-customize assay that can provide important information for vector-borne disease surveillance and research studies to efficiently complement current approaches.

microbiology↗

Active intermixing of indirect and direct neurons builds the striatal mosaic

The striatum controls behaviors via the activity of direct and indirect pathway projection neurons (dSPN and iSPN) that are intermingled in all compartments. While such mosaic ensures the balanced activity of the two pathways, how it emerges remains largely unknown. Here, we show that both SPN populations are specified embryonically and progressively intermix through multidirectional iSPN migration. Using conditional mutants of the dSPN-specific transcription factor Ebf1, we found that inactivating this gene impaired selective dSPN properties, including axon pathfinding, whereas molecular and functional features of iSPN were preserved. Remarkably, Ebf1 mutation disrupted iSPN/dSPN intermixing, resulting in an uneven distribution. Such architectural defect was selective of the matrix compartment, revealing that intermixing is a parallel process to compartment formation. Our study reveals that, while iSPN/dSPN specification is largely independent, their intermingling emerges from an active migration of iSPN, thereby providing a novel framework for the building of striatal architecture.

neuroscience↗