Biology subjects

Bastos, D. A.

Publications and source records attributed to Bastos, D. A..

3 recordsLinked to original sources

bioRxiv2022

Choice of 16S ribosomal RNA primers impacts urinary microbiota profiling

Accessibility to next-generation sequencing (NGS) technologies has enabled the profiling of microbial communities living in distinct habitats. 16S ribosomal RNA (rRNA) gene sequencing is widely used for microbiota profiling with NGS technologies. Since most used NGS platforms generate short reads, sequencing the full-length 16S rRNA gene is impractical. Therefore, choosing which 16S rRNA hypervariable region to sequence is critical in microbiota profiling studies. All nine 16S rRNA hypervariable regions are taxonomically informative, but due to variability in profiling performance for specific clades, choosing the ideal 16S rRNA hypervariable region will depend on the bacterial composition of the habitat under study. Recently, NGS allowed the identification of microbes in the urinary tract, and urinary microbiota has become an active research area. However, there is no current study evaluating the performance of different 16S rRNA hypervariable regions for urinary microbiota profiling. We collected urine samples from male volunteers and profiled their urinary microbiota by sequencing a panel of six amplicons encompassing all nine 16S rRNA hypervariable regions. After systematically comparing their performance, we show that V1V2 hypervariable regions better assess the taxa commonly present in urine samples and V1V2 amplicon sequencing is more suitable for urinary microbiota profiling. We believe our results will be helpful to guide this crucial methodological choice in future urinary microbiota studies.

microbiology↗

bioRxiv2021

The critical role of natural history museums in advancing eDNA for biodiversity studies: a case study with Amazonian fishes

Ichthyological surveys have traditionally been conducted using whole-specimen, capture-based sampling with varied, but conventional fishing gear. Recently, environmental DNA (eDNA) metabarcoding has emerged as a complementary, and possible alternative, approach to whole-specimen methodologies. In the tropics, where much of the diversity remains undescribed, vast reaches continue unexplored, and anthropogenic activities are constant threats; there have been few eDNA attempts for ichthyological inventories. We tested the discriminatory power of eDNA using MiFish primers with existing public reference libraries and compared this with capture-based methods in two distinct ecosystems in the megadiverse Amazon basin. In our study, eDNA provided an accurate snapshot of the fishes at higher taxonomic levels and corroborated its effectiveness to detect specialized fish assemblages. Some flaws in fish metabarcoding studies are routine issues addressed in natural history museums. Thus, by expanding their archives to include eDNA and adopting a series of initiatives linking collection-based research, training and outreach, natural history museums can enable the effective use of eDNA to survey Earths hotspots of biodiversity before taxa go extinct. Our project surveying poorly explored rivers and using DNA vouchered archives to build metabarcoding libraries for Neotropical fishes can serve as a model of this protocol.

ecology↗

bioRxiv2020

Social predation in electric eels

Social predation, when groups of predators coordinate actions to find and capture prey, is a common tactic among mammals but comparatively rare in fishes. We report the unexpected social predation by electric eels, an otherwise solitary predator in the Amazon rainforest. Observations made in different years and recorded on video show electric eels herding, encircling shoals of small nektonic fishes, and launching joint predatory high-voltage strikes on the prey ball. These findings challenge the hypothesis that electric eels may have a single foraging strategy, and extend our knowledge on social predation to an organism that employs high-voltage discharge for hunting, thereby offering a novel perspective for studies on the evolutionary interplay between predatory and escape tactics.

animal behavior and cognition↗