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Biology subjects

Dossou, L.

Publications and source records attributed to Dossou, L..

3 recordsLinked to original sources

eIFiso4G editing confers durable resistance against rice yellow mottle virus

Rice yellow mottle virus (RYMV) is one of the most devastating viral pathogens affecting rice cultivation in Africa. The eukaryotic translation initiation factor 4G isoform eIFiso4G1 plays a pivotal role in rice susceptibility to the virus. Naturally occuring resistance alleles impair infection but are predominantly found in the African cultivated species Oryza glaberrima, whose use in breeding programs is limited by interspecific sterility barriers with the widely grown O. sativa. Here, we used CRISPR-Cas9 to generate knockout (KO) mutations in eIFiso4G1 as well as insertion-deletion (Indel) variants within the region involved in interaction with the viral protein VPg. KO mutations conferred high resistance to RYMV. No resistance-breaking events were observed, suggesting that this resistance may be more durable than that conferred by naturally occuring alleles. However, complete gene KO slightly affected plant growth. Lines carrying Indel mutations in the VPg-interacting region displayed variable resistance levels, with some variants conferring high resistance without compromising plant development. Structural modeling of the eIFiso4G1 variants and their complexes with VPg provided mechanistic insights into how specific Indels modulate the resistance phenotype.

plant biology↗

Controlling Banana Bunchy Top Disease in Benin: crop protection strategies with socioeconomic perspectives

SummaryO_LIThis study combines satellite mapping, field surveillance, farmer surveys, and disease modelling to assess BBTV dynamics across Benin. It provides the first national-scale map of banana cultivation in Benin and identifies high-risk areas for targeted intervention. C_LIO_LIThe study highlights the dominance of informal networks for exchange of planting material ([~]80% of farmers), limited farmer awareness of BBTV ([~]60% unaware), and low recognition of symptoms or transmission routes, all of which contribute to the spread and persistence of disease. C_LIO_LIAlthough women represented only a quarter of respondents, they demonstrated comparable levels of market orientation and access to planting materials and land. The findings call for spatially targeted, socially informed BBTV management strategies that integrate clean planting material systems, farmer education, and accessible control methods. C_LIO_LIBBTV was detected in 140 out of 747 fields surveyed, with the highest prevalence in the humid southern regions. No cases were found in the northern Sudanian zone, reflecting known agroecological patterns of disease distribution. C_LIO_LIModelling of three control strategies - decapitation, uprooting, and injection - revealed injection as most effective nationally (70% reduction in disease incidence), while uprooting was most effective in vulnerable communities with high disease pressure. C_LIO_LIThe study reveals an interconnected system in which socioeconomic vulnerability, informal seed networks, limited disease awareness, and spatial clustering of banana cultivation collectively drive BBTV dynamics in Benin, highlighting the need for epidemiologically effective, socially informed, and spatially targeted interventions. C_LI Societal Impact StatementBanana and plantain are critical for food security and income generation in West Africa, particularly for smallholder farmers in countries such as Benin. However, banana bunchy top virus (BBTV) poses a major threat to sustainable production. This study integrates high-resolution remote sensing, field epidemiology, mathematical modelling, and socioeconomic analysis to improve understanding of the spread of BBTV and to evaluate the effectiveness of different disease control strategies. Our findings reveal that BBTV risk is highest in southern Benin, where socioeconomic vulnerability is also greatest. Low disease awareness, limited adoption of effective control methods and informal exchange of planting material exacerbate this risk. By identifying priority areas and strategies tailored to local social, economic, and agroecological contexts, this research offers a roadmap for designing targeted, sustainable BBTV management programs. These insights can support smallholder resilience, reduce disease burden, and safeguard banana-based livelihoods across sub-Saharan Africa.

plant biology↗

The IgCAM BT-IgSF (IgSF11) is essential for connexin43-mediated astrocyte-astrocyte and ependymal cell-cell coupling

The type I transmembrane protein BT-IgSF is predominantly localized in the brain and testes. It belongs to the CAR subgroup of Ig cell adhesion proteins, which have been hypothesized to regulate connexin expression or localization. Here, we studied the putative link between BT-IgSF and connexins in astrocytes, ependymal cells and neurons of the mouse. Global knockout of BT-IgSF caused an increase in the clustering of connexin43 (Gja1), but not of connexin30 (Gjb6), on astrocytes and ependymal cells. Additionally, knockout animals displayed reduced expression levels of connexin43 protein in the cortex and hippocampus. Importantly, analysis of biocytin spread in hippocampal or cortical slices from mature mice of either sex revealed a decrease in astrocytic cell-cell coupling in the absence of BT-IgSF. Blocking either protein biosynthesis or proteolysis showed that the lysosomal pathway increased connexin43 degradation. Localization of connexin43 in subcellular compartments was not impaired in the mutant. In contrast to connexin43 the localization and expression of connexin36 (Gjd2) on neurons was not affected by the absence of BT-IgSF. Overall, our data indicate that the IgCAM BT-IgSF is essential for correct gap junction-mediated astrocyte-to-astrocyte and ependymal cell-to-ependymal cell communication. Significance StatementAstrocytes regulate a variety of physiological processes in the developing and adult brain that are essential for proper brain function. Astrocytes form extensive networks in the brain and communicate via gap junctions. Disruptions of gap junction coupling are found in several diseases such as neurodegeneration or epilepsy. Here, we demonstrate that the cell adhesion protein BT-IgSF is essential for gap junction mediated coupling between astrocytes in the cortex and hippocampus.

cell biology↗