Biology subjects

Nunes, G.

Publications and source records attributed to Nunes, G..

4 recordsLinked to original sources

bioRxiv2026

A chromosome-level genome of the franciscana dolphin, Pontoporia blainvillei

The franciscana dolphin (Pontoporia blainvillei) is a small coastal cetacean endemic to the southwestern Atlantic Ocean and one of the most threatened marine mammals worldwide. It faces severe threats from bycatch, habitat degradation, and pollution. Classified as "Vulnerable" by the IUCN and "Critically Endangered" in Brazil, the species restricted range, strong fidelity to shallow waters, and low reproductive rate increase its extinction risk. Here, we present the first chromosome-level genome assembly for the franciscana dolphin, generated using PacBio HiFi long-read sequencing and Hi-C chromatin conformation capture. The final assembly totaled 3.13 Gb across 22 chromosomes (1500 scaffolds), consistent with the estimated karyotype of 2n = 44, with scaffold N50 of 111.18 Mb, high BUSCO completeness (99.42%), and a consensus quality value of 65.76. This high-quality genomic resource fills an important phylogenetic gap within Cetacea, enabling comparative and conservation studies. It provides an essential foundation for population genomics research to assess genetic diversity, structure, and connectivity, thereby supporting evidence-based conservation strategies for this endangered species.

genomics↗

bioRxiv2024

Population estimates of shorebirds on the Atlantic Coast of southern South America generated from large-scale, simultaneous, volunteer-led surveys

Population abundance and trend estimates are crucial to science, management, and conservation. Shorebirds, which are abundant in many coastal habitats and play important roles in coastal ecosystems, are facing some of the most dramatic population declines of any group of birds globally. However, accurate and up-to-date population estimates are lacking for most shorebird species. We thus conducted comprehensive, simultaneous, and community scientist-led surveys of the entire Atlantic Coast of southern South America -- stretching from central Brazil to Tierra del Fuego -- to gather counts of shorebirds that we combined with remote sensing analyses and two-step hurdle models that accounted for presence and abundance. Our objectives were to estimate shorebird densities by habitat, identify high-concentration areas, understand the environmental factors affecting their distributions, and provide population estimates for both Nearctic and Neotropical species. We counted a total of 37,207 shorebirds of 17 species and, from those counts, estimated that nearly 1.1 million shorebirds use the regions coastline. We also found that shorebirds occurred in the highest densities in shallow water wetland habitats and that fewer shorebirds occupied areas that were further away from estuaries. Although not directly comparable, our results suggest the population sizes of the Nearctic species whose nonbreeding ranges are predominantly in southern South America may have declined substantially since previous estimates. At the same time, our study represents the first empirically derived population estimates for Neotropical breeding shorebird species and indicates that they are far more abundant than previously thought. Taken together, our results highlight the power of community scientists to carry out structured protocols at continental scales and generate critical data for a group of at-risk species.

ecology↗

bioRxiv2022

Overview of the SARS-CoV-2 genotypes circulating in Latin America during 2021

Latin America is one of the regions in which the COVID-19 pandemic has had a stronger impact, with more than 72 million reported infections and 1.6 million deaths until June 2022. Since this region is ecologically diverse and is affected by enormous social inequalities, efforts to identify genomic patterns of the circulating SARS-CoV-2 genotypes are necessary for the suitable management of the pandemic. To contribute to the genomic surveillance of the SARS-CoV-2 in Latin America, we extended the number of SARS-CoV-2 genomes available from the region by sequencing and analyzing the viral genome from COVID-19 patients from seven countries (Argentina, Brazil, Costa Rica, Colombia, Mexico, Bolivia and Peru). Subsequently, we analyzed the genomes circulating mainly during 2021 including records from GISAID database from Latin America. A total of 1534 genome sequences were generated from seven countries, demonstrating the laboratory and bioinformatics capabilities for genomic surveillance of pathogens that have been developed locally. For Latin America, patterns regarding several variants associated with multiple re-introductions, a relatively low percentage of sequenced samples, as well as an increment in the mutation frequency since the beginning of the pandemic, are in line with worldwide data. Besides, some variants of concern (VOC) and variants of interest (VOI) such as Gamma, Mu and Lambda, and at least 83 other lineages have predominated locally with a country-specific enrichments. This work has contributed to the understanding of the dynamics of the pandemic in Latin America as part of the local and international efforts to achieve timely genomic surveillance of SARS-CoV-2.

microbiology↗

bioRxiv2022

Pathogenicity of novel Monosporascus species in accessions of four melon botanical groups

The Monosporascus root rot and vine decline (MRRVD) can be caused by the fungal species Monosporascus cannonballus and M. eutypoides. The Monosporascus species recently described in Brazil (M. brasiliensis, M. caatinguensis, M. mossoroensis, M. nordestinus and M. semiaridus) are potentially causal agents of the MRRVD. This work was made to evaluate them comparing to M. cannonballus pathogenicity, and to evaluate melon accessions reaction in four botanical groups of melon. MRRVD was evaluated by the severity of the damages in the roots and by the root dry matter reduction index (RIDM). On average, the studied species caused damage to melon accessions. After all, only M. brasiliensis, M. caatinguensis and M. nordestinus were virulent according to the accessions evaluated (A-16, C-32 syn. Pat 81, Goldex and HBJ), i.e., accession-species interaction occurred, and among them, M. caatinguensis was the most virulent. The accession A-16 (acidulus group) showed higher resistance (<10 % of root dry mass loss) to M. cannonballus, M. caatinguensis and M. nordestinus. The accession C-32 was susceptible to M. caatinguensis and moderately resistant to the others. The accession A-16 was the most promising one and can be used as a donor of resistance alleles or as a rootstock.

plant biology↗