Biology subjects

Luviano, N.

Publications and source records attributed to Luviano, N..

4 recordsLinked to original sources

bioRxiv2024

Transcriptomic plasticity in hybrid schistosomes can contribute to their zoonotic potential

Hybrids between Schistosoma haematobium and S. bovis are linked to both human and animal infections, highlighting the complex interspecies interactions that contribute to the spread of schistosomiasis. Additionally, S. bovis can infect multiple ruminant hosts, facilitating cross- species transmission and increasing the risk of zoonotic outbreaks. In this study, we investigated transcriptomic plasticity as a potential mechanism enabling hybrid schistosomes to adapt to alternative definitive hosts. We focused on two contexts: 1) introgressed S. haematobium x S. bovis hybrids, which demonstrated higher virulence in sheep compared to parental S. bovis, and 2) S. bovis infecting different host species. Our analysis uncovered 366 differentially expressed genes (DEGs), representing 4% of the total protein-coding genes, between introgressed hybrids and parental S. bovis in sheep. We also identified transcriptomic changes in S. bovis across different mammalian hosts (hamster and sheep), with around 30% of the total genes differentially expressed, demonstrating that S. bovis parasites display a high transcriptomic plasticity, allowing them to infect different definitive hosts. Shared enriched biological processes during introgression and host change include nuclear-transcribed mRNA catabolic processes, inner mitochondrial membrane organization, microtubule-based movement, response to endoplasmic reticulum stress, and sensory perception. These findings suggest that transcriptomic plasticity in S. bovis and hybrid worms enhance their ability to adapt and infect diverse host species, potentially increasing their zoonotic potential. This raises concerns for schistosomiasis epidemiology, as this plasticity could expand the parasites transmission capacity and complicate control efforts.

evolutionary biology↗

bioRxiv2023

Epigenetic variation causes heritable variation in complex traits in the mollusk Biomphalaria glabrata, vector of the human parasite Schistosoma mansoni

DNA methylation variation may play a role in phenotypic variation as it can be directly affected by the environment and be inherited. DNA methylation variations were introduced into the parasite vector snail Biomphalaria glabrata with low genetic diversity by chemical treatment in F0 and followed over 3 generations using epigenetic recombinant inbred lines (epiRILs). We observed phenotypic variation in complex traits such as fecundity and susceptibility to infestation by Schistosoma mansoni and DNA methylation differences in F3. Both, increase and decrease of infestation success (up to 100% and down to 20% prevalence in epiRILs and from 86% to 94% in control RILs) indicated variation in complex resistance/compatibility trait. Average prevalence in control RILs was 84{+/-}5% but only 68{+/-}21 % in epiRILs. Fecundity also changed and was in average 47{+/-}7% in control RILs and 59{+/-}18% in epiRILs, being 12% higher in epiRILs. We found that the heritability h2 of the fecundity in the epiRILs was between 0.5 and 0.6 depending on the method used to estimate it. We developed a model for introducing epimutant offspring snails into resident susceptible populations. If genetic assimilation of the resistant phenotype occured in a small fraction of the introduced epimutant snails, we predict that the susceptible phenotype is replaced by the resistant phenotype after 50-70 generations.

ecology↗

bioRxiv2023

An epigenetic molluscicide

Biomphalaria glabrata is a fresh-water mollusk that serves as obligatory intermediate host to Schistosoma mansoni, agent of the neglected tropical disease schistosomiasis that affects roughly 250 Mio people. One of the ways to control the pathogenic agent is to interrupt the life cycle by eliminating the intermediate snail host though foal treatment of water bodies with molluscicides. Currently recommended molluscicides were developed in the 1950ths and lack sufficient specificity, e.g., they are toxic to fish. To provide new lead compounds for the development of a new type of molluscicides we used a rational approach based on the hypotheses that interfering with an important epigenetic mark, DNA methylation, would impede development of the snail host. We present here the compound 29, analogues-based compound that mimic substrates of DNA methyltransferases. We show that compound 29 has (i) low cytotoxicity for human cells, (ii) it inhibits DNA methylation, and (iii) it decreases fecundity in B.glabrata. It is therefore conceivable to produce compounds that act as specific epigenetic molluscicides.

molecular biology↗

bioRxiv2018

A simple Dot Blot Assay for population scale screening of DNA methylation

The study of epigenetic changes in natural and experimental populations has increased the need to find a cost-effective and high throughput method to analyze multiple samples to effectuate a population-wide screening to study epigenetic changes triggered by biotic or abiotic stress. One of the most studied epigenetic marks is global DNA methylation, its measurement is used as a first step to differentiate methylation between individuals. There is a wide range of methods designed to detect genome-wide 5 methyl-cytosine (5mC) that differ in sensitivity, price, level of expertise required, but as a general rule, require large amounts of DNA and are relatively expensive. This is a limit for the analysis of 5mC in a large number of individuals as a prerequisite to population-wide testing of methylation markers. In this work, we evaluated a method based on antibody recognition of 5mC to measure the DNA methylation level of individuals of the species Biomphalaria glabrata, the intermediate host of schistosomiases, a neglected tropical disease. We validated the method to complete a large screening in the genome of B. glabrata snails treated with a chemical inhibitor of DNA methylation; however, the method can be applied to any species containing 5mC. The dot blot assay is a suitable method to perform a large-scale screening of global DNA methylation to compare 5mC levels between individuals from different natural or experimental populations. The dot blot method compares favorably with methods with an equivalent sensitivity such as the Enzyme Linked Immunosorbent Assay (ELISA) kit since it requires a smaller amount of DNA (30 ng) is less expensive and allows many more samples to be analyzed.

ecology↗