Biology subjects

Noya, O.

Publications and source records attributed to Noya, O..

4 recordsLinked to original sources

bioRxiv2024

Genomic exploration of the complex journey of Plasmodium vivax in Latin America

Plasmodium vivax, the predominant malaria parasite in Latin America, has a rich and complex colonization history in the region, with debated hypotheses about its origin. Our study employed cutting-edge population genomic techniques, to collect whole genome sequencing data from 620 P. vivax isolates, including 107 newly sequenced samples, thus representing nearly all potential source populations worldwide. Analyses of the genetic structure, diversity, ancestry, and also, coalescent-based inferences and scenario testing using Approximate Bayesian Computation, have revealed a more complex evolutionary history than previously envisioned. Indeed, according to our analysis, the current American P. vivax populations predominantly stemmed from a now-extinct European lineage, with the potential contribution also from unsampled populations, most likely of West African origin, during post-colonial human migration waves in the late 19th-century. This study provides a fresh perspective on P. vivax intricate evolutionary journey and brings insights into the possible contribution of West African P. vivax populations to the colonization history of Latin America.

genomics↗

bioRxiv2020

Genome analysis of the fatal tapeworm Sparganum proliferum unravels the cryptic lifecycle and mechanisms underlying the aberrant larval proliferation

BackgroundThe cryptic parasite Sparganum proliferum proliferates in humans and invades tissues and organs. Only scattered cases have been reported, but S. proliferum infection is always fatal. However, the S. proliferum phylogeny and lifecycle are still an enigma. ResultsTo investigate the phylogenetic relationships between S. proliferum and other cestode species, and to examine the underlying mechanisms of pathogenicity, we sequenced the entire S. proliferum genome. Additionally, S. proliferum plerocercoid larvae transcriptome analyses were performed to identify genes involved in asexual reproduction in the host. The genome sequences confirmed that the S. proliferum genetic sequence is distinct from that of the closely related Spirometra erinaceieuropaei. Moreover, nonordinal extracellular matrix coordination allows for asexual reproduction in the host and loss of sexual maturity in S. proliferum is related to its fatal pathogenicity in humans. ConclusionsThe high-quality reference genome sequences generated should prove valuable for future studies of pseudophyllidean tapeworm biology and parasitism.

genomics↗

bioRxiv2020

Malaria in Southern Venezuela: The Hottest Hotspot in Latin America

Malaria cases in Latin America reached ~1 million in 2017 and 2018, with 53% and 51% reported from Venezuela, respectively. In this study, we characterized the spatiotemporal dynamics of malaria transmission between 2007-2017 in southern Venezuela, the main endemic area of the country. We found that disease transmission was focal and more prevalent in the southeast of southern Venezuela where two persistent hotspots of Plasmodium vivax (76%) and P. falciparum (18%) linked to deforestation for illegal gold mining accounted for ~60% of the country-wide number of cases. Incidence has increased nearly tenfold in the last decade, showing an explosive epidemic growth due to a significant lack of disease control. We suggest that a source-sink pattern of Plasmodium sp. dispersal account for the re-emergence and progression of malaria transmission in the last 4 years across the country due to the internal migration of infected people to and from the hotspots and other malaria-prone ecosystems. We observe a similar pattern explaining the spillover of cases across international borders affecting neighboring countries. This study provides baseline epidemiological data and guidance for malaria control to further assess the dynamics of cross-border malaria, the role of asymptomatic carriers, drug-resistant evolution, and innovative control efforts in the Latin America region.

ecology↗

bioRxiv2019

Systematics and geographical distribution of Galba species, a group of cryptic and worldwide freshwater snails

Cryptic species can present a significant challenge to the application of systematic and biogeographic principles, especially if they are invasive or transmit parasites or pathogens. Detecting cryptic species requires a pluralistic approach in which molecular markers facilitate the detection of coherent taxonomic units that can then be analyzed using various traits (e.g., internal morphology) and crosses. In asexual or self-fertilizing species, the latter criteria are of limited use. We studied a group of cryptic freshwater snails (genus Galba) from the family Lymnaeidae that have invaded almost all continents, reproducing mainly by self-fertilization and transmitting liver flukes to humans and livestock. We aim to clarify the systematics, distribution and phylogenetic relationships of these species with an integrative approach that includes morphology (shell and reproductive anatomy), molecular markers, wide-scale sampling across America, and data retrieved from GenBank (to include Old World samples). Our phylogenetic analysis suggests that the genus Galba originated ca. 22 Myr ago and today comprises six clusters of species. Four of these clusters (G. truncatula, G. cubensis/viator, G. humilis and G. schirazensis) are morphologically cryptic and constitute species or species complexes with wide variation in their genetic diversity, geographic distribution and invasiveness. The other two clusters constitute a single species or a species complex (Galba cousini/meridensis) that demonstrate more geographically restricted distributions and exhibit an alternative morphology more phylogenetically derived than the cryptic one. Further genetic studies are required to clarify the status of both G. cousini/meridensis and G. cubensis/viator. We emphasize that no Galba species should be identified without molecular markers and that additional sampling is required, especially in North America, Eurasia and Africa to clarify remaining questions in systematics and biogeography. We also discuss several hypotheses that can explain crypsis in Galba, such as convergence and morphological stasis, and hypothesize a role for stabilizing selection in amphibious (rather than strictly freshwater) habitats.

evolutionary biology↗