Biology subjects

Diouf, B.

Publications and source records attributed to Diouf, B..

3 recordsLinked to original sources

bioRxiv2026

Lack of Evidence for Local Adaptation in Risk Tolerance: A Genetic Study in Northern Senegal.

Risk tolerance is influenced by both environmental and genetic factors and may be shaped by local selective pressures in hazardous environments. In Northern Senegal, fishermen from the village of Guet Ndar are chronically exposed to high occupational mortality risk, making this population a potential model for local adaptation to risky environments. In a previous study, we showed that men from this fishing community were less risk-tolerant than men from a nearby farming village, although this difference could not be explained by variation at the DRD4 locus. Here, we investigated whether genetic variants previously associated with general risk tolerance in large genome-wide association studies (GWAS) exhibit signals of local adaptation in these Senegalese populations. We genotyped 44 candidate SNPs in 373 individuals sampled from the risky fishing area and the non-risky farming area. Population genetic analyses revealed extremely low and non-significant differentiation between the two populations (mean FST = 0.0003, p = 0.33), indicating that the two groups are genetically indistinguishable at these loci. Furthermore, none of the candidate SNPs showed a significant association with experimentally measured risk tolerance after correction for multiple testing. These results provide no evidence that local adaptation for risky behavior has occurred, several explanations may account for this negative result.

evolutionary biology↗

bioRxiv2023

Inoculation dose, formulation and air temperature shape Metarhizium anisopliae virulence against the oriental fruit fly: lessons for improving on-target control strategies

Entomopathogenic fungi are a promising tool for the biological control of crop pests provided low or no impact on non-target organisms. Selection for host specificity as well as on-target applications open new avenues for more sustainable strategies for pest management. Isolates of Metarhizium anisopliae (Metschn.) Sorokin have been identified as promising for developing innovative entomovectoring-based strategies for the control of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in Africa. To be effective, this technology requires high strain virulence at a low number of spores, but sufficient incubation time to allow transmission to wild conspecifics. This depends on trophic interactions between the host and the pathogen, which are mediated by abiotic factors. In the present study, we investigated the virulence of the Met69 strain against adult flies, depending on the inoculation dose, air temperature and formulation. High pathogenicity was observed at very low inoculation doses (LT50 of 4.85 days with 6100 spores per fly) independently of fly sex. Virulence increased with spore load in a tight range (5600 and 6100 spores per fly) and with air temperature observed in the field (20-28{degrees}C). Unexpectedly, corn starch used as an adjuvant to increase the carrying capacity of insects decreased the virulence of the pathogen. The results will help improve area-wide control strategies based on the contamination of wild flies through auto-inoculation devices or interactions with released mass-reared sterile males coated with fungal spores. Furthermore, the study proposes an approach for calibrating area-wide control strategies, taking into account both the insect and pathogen bioecology and the environment in which they evolve. Author rolesAnais Chailleux: Conceptualization, Funding acquisition, Methodology, Data curation, Writing - original draft. Oumou Noumou Coulibaly: Investigation, Writing - original draft. Babacar Diouf: Investigation, Visualization. Samba Diop: Investigation. Ahmad Sohel: Resources, Writing - review & editing. Thierry Brevault: Conceptualization, Funding acquisition, Project administration, Writing - review & editing.

zoology↗

bioRxiv2023

The influence of the larval microbiome on susceptibility to Zika virus is mosquito genotype dependent

The microbiome of the mosquito Aedes aegypti is largely determined by the environment and influences mosquito susceptibility for arthropod-borne viruses (arboviruses). Larval interactions with different bacteria can influence adult Ae. aegypti replication of arboviruses, but little is known about the role that mosquito host genetics play in determining how larval-bacterial interactions shape Ae aegypti susceptibility to arboviruses. To address this question, we isolated single bacterial isolates and complex microbiomes from Ae. aegypti larvae from various field sites in Senegal. Either single bacterial isolates or complex microbiomes were added to two different genetic backgrounds of Ae. aegypti in a gnotobiotic larval system. Using 16S amplicon sequencing we show that similarities in bacterial community structures when given identical microbiomes between different genetic backgrounds of Ae. aegypti was dependent on the source microbiome, and the abundance of single bacterial taxa differed between Ae. aegypti genotypes. Using single bacterial isolates or the entire preserved complex microbiome, we tested the ability of specific microbiomes to drive differences in infection rates for Zika virus in different genetic backgrounds of Ae. aegypti. We observed that the proportion of Zika virus-infected adults was dependent on the interaction between the larval microbiome and Ae. aegypti host genetics. By using the larval microbiome as a component of the environment, these results demonstrate that interactions between the Ae. aegypti genotype and its environment can influence Zika virus infection. As Ae. aegypti expands and adapts to new environments under climate change, an understanding of how different genotypes interact with the same environment will be crucial for implementing arbovirus transmission control strategies.

microbiology↗