Biology subjects

Oliveira, R. R. M.

Publications and source records attributed to Oliveira, R. R. M..

5 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

Pipeasm: a tool for automated large chromosome-scale genome assembly and evaluation

MotivationWith increasing initiatives to study biodiversity through high-quality reference genomes and the growing capacity of sequencing a wide range of organisms, there is a pressing need for an accessible, reproducible, and user-friendly tool that incorporates state-of-the-art methodologies for large genome assembly. ResultsWe introduce Pipeasm, a Snakemake pipeline designed for assembling vertebrate genomes using HiFi PacBio, ONT, and HiC data. By setting a configuration file with input information and suggested parameters, Pipeasm was able to assemble multiple-sized diploid genomes ready for manual curation. Availability and ImplementationPipeasm requires an environment with Snakemake and Singularity and is available at https://github.com/itvgenomics/pipeasm.

bioinformatics↗

bioRxiv2023

Yerba mate (Ilex paraguariensis) genome provides new insights into convergent evolution of caffeine biosynthesis

Yerba mate (Ilex paraguariensis) is an economically important crop marketed for the elaboration of mate, the third-most widely consumed caffeine-containing infusion worldwide. Here we report the first genome assembly of this species, which has a total length of 1.06 Gb and contains 53,390 protein-coding genes. Comparative analyses revealed that the large yerba mate genome size is partly due to a whole-genome duplication (Ip-) during the early evolutionary history of Ilex, in addition to the hexaploidization event ({gamma}) shared by core eudicots. Characterization of the genome allowed us to clone the genes encoding methyltransferase enzymes that catalyse multiple reactions required for caffeine production. To our surprise, this species has converged upon a different biochemical pathway compared to that of its relatives, coffee and tea. In order to gain insight into the structural basis for the convergent enzyme activities, we obtained a crystal structure for the terminal enzyme in the pathway that forms caffeine. The structure reveals that convergent solutions have evolved for substrate positioning because different amino acid residues facilitate a different substrate orientation such that efficient methylation occurs in the independently evolved enzymes in yerba mate and coffee. While our results show phylogenomic constraint limits the genes coopted for convergence of caffeine biosynthesis, the x-ray diffraction data suggests structural constraints are minimal for the convergent evolution of individual reactions.

plant biology↗

bioRxiv2021

PIMBA: a PIpeline for MetaBarcoding Analysis

SummaryDNA metabarcoding is an emerging monitoring method capable of assessing biodiversity from environmental samples (eDNA). Advances in computational tools have been required due to the increase of Next-Generation Sequencing data. Tools for DNA metabarcoding analysis, such as MOTHUR, QIIME, Obitools, and mBRAVE have been widely used in ecological studies. However, some difficulties are encountered when there is a need to use custom databases. Here we present PIMBA, a PIpeline for MetaBarcoding Analysis, which allows the use of customized databases, as well as other reference databases used by the softwares mentioned here. PIMBA is an open-source and user-friendly pipeline that consolidates all analyses in just three command lines. Availability and Implementationhttps://github.com/reinator/pimba Contactrenato.renison@gmail.com and guilherme.oliveira@pq.itv.org.

bioinformatics↗

bioRxiv2017

Complete mitochondrial genome of Glomeridesmus spelaeus (Diplopoda), a troglobitic species from Carajas iron-ore caves (Para, Brazil)

We report the complete mitochondrial genome sequence of Glomeridesmus spelaeus, the first sequenced genome of the order Gomeridesmida. The genome is 14,825 pb in length and encodes 37 mitochondrial (13 PCGs, 2 rRNA genes, 22 tRNA) genes and contains a typical AT-rich region. The base composition of the genome was A (40.1%), T (36.4%), C (15.8%), and G (7.6%), with an AT content of 76.5%. Our results indicated that Glomeridesmus spelaeus only distantly related to the other Diplopoda species with available mitochondrial genomes in the public databases. The publication of the mitogenome of G. spelaeus will contribute to the identification of troglobitic invertebrates, a very significant advance for the conservation of the troglofauna.

genomics↗