Establishment of a cell culture from the frog Leptodactylus fuscus as a model for (eco)toxicological assays.

Leptodactylus fuscus is a frog species widely distributed in the Neotropical region, occurring in several biomes, which makes it a potential biomonitor of environmental conditions. To advance the establishment of this species in this field, we developed a fibroblast-like cell line derived from the digits of the forelimbs (LFUfd) and evaluated its response to possible environmental stressors. An adult male L.

Natural modulation of redox status throughout the ontogeny of Amazon frog Physalaemus ephippifer (Anura, Leptodactylidae).

During their development, amphibians undergo various physiological processes that may affect their susceptibility to environmental pollutants. Naturally occurring fluctuations caused by developmental events are often overlooked in ecotoxicological studies. Our aim is to investigate how biomarkers of oxidative stress are modulated at different stages of larval development in the Amazonian amphibian species, Physalaemus ephippifer.

Conditions for establishing fin primary cell cultures in a wide range of ray-finned fishes.

Ray-finned fishes (Actinopterygii) represent the most diverse vertebrate lineage that show extensive variations in physiology, ways of life, and adaptations to marine and freshwater environments, and several species have been established as biological research models. The in vitro culture of cells is fundamental for several fields of biological research, being an alternative for studies that use animals. Hundreds of fish cell lines have been established using specific methods for each cell type and species.

Sodium valproate affects the expression of p16 and p21 cyclin‑dependent kinase inhibitors in HeLa cells.

p16 and p21 are cyclin-dependent kinase inhibitors involved in cell cycle control, which can function as oncogenes or tumor suppressors, depending on the context of various extracellular and intracellular signals, and cell type. In human papillomavirus-induced cervical cancer, shows oncogenic activity and functions as a diagnostic marker of cervical neoplasia, whereas acts as a tumor suppressor and its downregulation is associated with the progression of malignant transformation. Several histone deacetylase (HDAC) inhibitors promote the positive and negative regulation of a number of genes, including and ; however, the effects of sodium valproate (VPA) on these genes and on the proteins they encode remain uncertain in HeLa cervical cancer cells.

Chromosomal organization of multigene families and meiotic analysis in species of Loricariidae (Siluriformes) from Brazilian Amazon, with description of a new cytotype for genus Spatuloricaria.

In the Amazon, some species of Loricariidae are at risk of extinction due to habitat loss and overexploitation by the ornamental fish market. Cytogenetic data related to the karyotype and meiotic cycle can contribute to understanding the reproductive biology and help management and conservation programs of these fish. Additionally, chromosomal mapping of repetitive DNA in Loricariidae may aid comparative genomic studies in this family.

Absence of maternal-fetal adverse effects of . Beauv. following treatment during pregnancy in mice.

P. Beauv is a plant native to Brazil that exhibits various beneficial activities including antioxidant, antibacterial, antifungal, antiprotozoal, anti-hyperalgesic, and anti-inflammatory properties. The aim of this study was to assess the impact of the ethanol extract of (EEAl) on reproductive outcomes, embryofetal development, and DNA integrity of pregnant female mice.

Characterization of repetitive DNA on the genome of the marsh rat Holochilus nanus (Cricetidae: Sigmodontinae).

Repetitive DNA are sequences repeated hundreds or thousands of times and an abundant part of eukaryotic genomes. SatDNA represents the majority of the repetitive sequences, followed by transposable elements. The species Holochilus nanus (HNA) belongs to the rodent tribe Oryzomyini, the most taxonomically diverse of Sigmodontinae subfamily.

Kinetic Activity of Chromosomes and Expression of Recombination Genes in Achiasmatic Meiosis of () Scorpions.

Several species of (Scorpiones, Buthidae) present multi-chromosomal meiotic associations and failures in the synaptic process, originated from reciprocal translocations. Holocentric chromosomes and achiasmatic meiosis in males are present in all members of this genus. In the present study, we investigated synapse dynamics, transcriptional silencing by γH2AX, and meiotic microtubule association in bivalents and a quadrivalent of the scorpion .

Karyotypes of Manatees: New Insights into Hybrid Formation ( × ) in the Amazon Estuary.

Great efforts have been made to preserve manatees. Recently, a hybrid zone was described between (TIN) and the (TMM) in the Amazon estuary. Cytogenetic data on these sirenians are limited, despite being fundamental to understanding the hybridization/introgression dynamics and genomic organization in .

Meiotic behavior, transmission and active genes of B chromosomes in the cichlid Astatotilapia latifasciata: new clues about nature, evolution and maintenance of accessory elements.

Supernumerary B chromosomes (Bs) are dispensable genetic elements widespread in eukaryotes and are poorly understood mainly in relation to mechanisms of maintenance and transmission. The cichlid Astatotilapia latifasciata can harbor Bs in a range of 0 (named B -) and 1-2 (named B +). The B in A.

Differential expression of miRNAs in the presence of B chromosome in the cichlid fish Astatotilapia latifasciata.

Background: B chromosomes (Bs) are extra elements observed in diverse eukaryotes, including animals, plants and fungi. Although Bs were first identified a century ago and have been studied in hundreds of species, their biology is still enigmatic. Recent advances in omics and big data technologies are revolutionizing the B biology field.

B chromosomes of multiple species have intense evolutionary dynamics and accumulated genes related to important biological processes.

Background: One of the biggest challenges in chromosome biology is to understand the occurrence and complex genetics of the extra, non-essential karyotype elements, commonly known as supernumerary or B chromosomes (Bs). The non-Mendelian inheritance and non-pairing abilities of B chromosomes make them an interesting model for genomics studies, thus bringing to bear different questions about their genetic composition, evolutionary survival, maintenance and functional role inside the cell. This study uncovers these phenomena in multiple species that we considered as representative organisms of both vertebrate and invertebrate models for B chromosome analysis.

De novo genome assembly of the cichlid fish Astatotilapia latifasciata reveals a higher level of genomic polymorphism and genes related to B chromosomes.

Supernumerary B chromosomes (Bs) are accessory elements to the regular chromosome set (As) and have been observed in a huge diversity of eukaryotic species. Although extensively investigated, the biological significance of Bs remains enigmatic. Here, we present de novo genome assemblies for the cichlid fish Astatotilapia latifasciata, a well-known model to study Bs.

Karyotypic Diversity and Evolution in a Sympatric Assemblage of Neotropical Electric Knifefish.

Chromosome changes can perform an important role in speciation by acting as post-zygotic reproductive barriers. The Neotropical electric fish genus (Gymnotiformes, Hypopomidae) has 28 described species, but cytogenetic data are hitherto available only for four of them. To understand karyotype evolution and investigate the possible role of chromosome changes in the diversification of this genus, we describe here the karyotype of eight species of from a sympatric assemblage in the central Amazon basin.

In Situ Localization of Ribosomal Sites in Peckoltia and Ancistomus (Loricariidae: Hypostominae) from the Amazon Basin.

Loricariidae is a diverse group of fish from the neotropical region, occupying a wide variety of freshwater environments. Cytogenetic data have brought important insights into Loricariidae diversity because they help validate undescribed species as well as our understanding of inter- and intraspecific diversity. However, conventional cytogenetic approaches are limited in their ability to detect variability in some lineages, as seen in the Peckoltia clade, owing to their apparent conserved karyotype.

The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata.

Background: Satellite DNAs (satDNAs) are organized in repetitions directly contiguous to one another, forming long arrays and composing a large portion of eukaryote genomes. These sequences evolve according to the concerted evolution model, and homogenization of repeats is observed at the intragenomic level. Satellite DNAs are the primary component of heterochromatin, located primarily in centromeres and telomeres.

The hnRNP Q-like gene is retroinserted into the B chromosomes of the cichlid fish Astatotilapia latifasciata.

B chromosomes are dispensable elements observed in many eukaryotic species, including the African cichlid Astatotilapia latifasciata, which might have one or two B chromosomes. Although there have been many studies focused on the biology of these chromosomes, questions about the evolution, maintenance, and potential effects of these chromosomes remain. Here, we identified a variant form of the hnRNP Q-like gene inserted into the B chromosome of A.

Gymnotus coatesi (Gymnotiformes): A Case of Colocation of Multiple Sites of 18S rDNA with Telomeric Sequences.

Gymnotus coatesi is a small and rare species of banded knife fish that was originally described by LaMonte in 1935, found along the main stretch of the Amazon River. There is no described cytogenetic data on this species. We analyzed the karyotype of five specimens of G.

The Karyotype of Microsternarchus aff. bilineatus: A First Case of Y Chromosome Degeneration in Gymnotiformes.

Various species and lineages that until recently were identified as Microsternarchus bilineatus (Hypopomidae, Gymnotiformes) have a widespread distribution in the Amazon and Orinoco River basins and across the Guiana shield. Recent molecular studies show five distinct lineages for Microsternarchus from different localities. These results suggest that this previously monotypic genus actually consists of more than one species.

Karyotypic Evolution and Chromosomal Organization of Repetitive DNA Sequences in Species of Panaque, Panaqolus, and Scobinancistrus (Siluriformes and Loricariidae) from the Amazon Basin.

Loricariidae family comprises the greatest variability of Neotropical catfish species, with more than 800 valid species. This family shows significant chromosomal diversity. Mapping of repetitive DNA sequences can be very useful in exploring such diversity, especially among groups that appear to share a preserved karyotypic macrostructure.

The repetitive DNA element BncDNA, enriched in the B chromosome of the cichlid fish Astatotilapia latifasciata, transcribes a potentially noncoding RNA.

Supernumerary chromosomes have been studied in many species of eukaryotes, including the cichlid fish, Astatotilapia latifasciata. However, there are many unanswered questions about the maintenance, inheritance, and functional aspects of supernumerary chromosomes. The cichlid family has been highlighted as a model for evolutionary studies, including those that focus on mechanisms of chromosome evolution.