Cytogenetic and molecular characteristics of Potamotrygon motoro and Potamotrygon sp. (Chondrichthyes, Myliobatiformes, Potamotrygonidae) from the Amazon basin: Implications for the taxonomy of the genus
Abstract The chromosomes of two freshwater stingrays, Potamotrygon motoro and Potamotrygon sp., from the Amazon River basin in Brazil were investigated using integrated molecular (cytochrome c oxidase subunit 1) and cytogenetic analyses. Potamotrygon motoro presented intraspecific variation in the diploid number, with 2n=66 in the females and 2n=65 in the males, while Potamotrygon sp. had a karyotype with 66 chromosomes, in both sexes. The C-banding revealed the presence of heterochromatic blocks accumulated in the centromeric region of all the chromosomes in both species. The FISH assays with 18S DNA probes highlighted th...
Source: Genetics and Molecular Biology - April 8, 2021 Category: Genetics & Stem Cells Source Type: research
The paradox of autophagy in Tuberous Sclerosis Complex
Abstract Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of ham...
Source: Genetics and Molecular Biology - April 5, 2021 Category: Genetics & Stem Cells Source Type: research
Fantastic databases and where to find them: Web applications for researchers in a rush
Abstract Public databases are essential to the development of multi-omics resources. The amount of data created by biological technologies needs a systematic and organized form of storage, that can quickly be accessed, and managed. This is the objective of a biological database. Here, we present an overview of human databases with web applications. The databases and tools allow the search of biological sequences, genes and genomes, gene expression patterns, epigenetic variation, protein-protein interactions, variant frequency, regulatory elements, and comparative analysis between human and model organisms. Our goal is to p...
Source: Genetics and Molecular Biology - April 2, 2021 Category: Genetics & Stem Cells Source Type: research
Cytotaxonomy of Gallinula melanops (Gruiformes, Rallidae): Karyotype evolution and phylogenetic inference
Abstract Although Rallidae is the most diverse family within Gruiformes, there is little information concerning the karyotype of the species in this group. In fact, Gallinula melanops, a species of Rallidae found in Brazil, is among the few species studied cytogenetically, but only with conventional staining and repetitive DNA mapping, showing 2n=80. Thus, in order to understand the karyotypic evolution and phylogeny of this group, the present study aimed to analyze the karyotype of G. melanops by classical and molecular cytogenetics, comparing the results with other species of Gruiformes. The results show that G. melanops...
Source: Genetics and Molecular Biology - April 2, 2021 Category: Genetics & Stem Cells Source Type: research
Genetic structure of the endangered Irrawaddy dolphin (Orcaella brevirostris) in the Gulf of Thailand
Abstract The Irrawaddy dolphin (Orcaella brevirostris) is an endangered, small cetacean species which is widely distributed in rivers, estuaries, and coastal waters throughout the tropical and subtropical Indo-Pacific. Despite the extensive distribution of this species, little is known of individual movements or genetic exchange among regions in Thailand. Here, we evaluate the genetic diversity and genetic structure of O. brevirostris in the eastern, northern and western Gulf of Thailand, and Andaman Sea. Although phylogenetic relationships and network analysis based on 15 haplotypes obtained from 32 individuals reveal no ...
Source: Genetics and Molecular Biology - April 2, 2021 Category: Genetics & Stem Cells Source Type: research
Gene expression evaluation of antioxidant enzymes in patients with hepatocellular carcinoma: RT-qPCR and bioinformatic analyses
Abstract Any condition leading to chronic liver disease is a potential oncogenic agent for hepatocellular carcinoma (HCC). Alterations in the expression of antioxidant enzymes could alter the redox balance. Our aim was to evaluate the expression of the genes GPX1, GPX4, SEP15, SELENOP, SOD1, SOD2, GSR, CAT, and NFE2L2 in patients with HCC. Differential gene expression analysis was performed using RNA-Seq data from the TCGA and GTEx databases, and RT-qPCR data from HCC patient samples. Bioinformatic analysis revealed significant differential expression in most genes. GPX4 expression was significantly increased (p=0.02), whi...
Source: Genetics and Molecular Biology - April 2, 2021 Category: Genetics & Stem Cells Source Type: research
Establishment of rapid and non-invasive protocols to identify B-carrying individuals of Psalidodon paranae
Abstract Supernumerary, or B, chromosomes are present in several eukaryotes, including characid fish of the genus Psalidodon. Notably, Psalidodon paranae carries the most studied B chromosome variant, a macro-B chromosome. The origin of this element was determined to be an isochromosome; however, data regarding its inheritance remain unavailable due to methodological barriers such as the lack of an efficient, non-invasive, and rapid protocol for identifying B-carrying individuals that would enable the design of efficient crossing experiments. Thus, in this study, we primarily aimed was to develop two non-invasive and fast ...
Source: Genetics and Molecular Biology - March 26, 2021 Category: Genetics & Stem Cells Source Type: research
Alpha thalassemia and alpha-MRE haplotypes in Uruguayan patients with microcytosis and hypochromia without anemia
Abstract Alpha thalassemia is the most common genetic disorder across the world, being the α -3.7 deletion the most frequent mutation. In order to analyze the spectrum and origin of alpha thalassemia mutations in Uruguay, we obtained a sample of 168 unrelated outpatients with normal hemoglobin levels with microcytosis and hypochromia from two cities: Montevideo and Salto. The presence of α -thalassemia mutations was investigated by gap-PCR, restriction endonucleases analysis and HBA2 and HBA1 genes sequencing, whereas the alpha-MRE haplotypes were investigated by sequencing. We found 55 individuals (32.7%) with α -thala...
Source: Genetics and Molecular Biology - March 26, 2021 Category: Genetics & Stem Cells Source Type: research
Cytogenetic and genetic data support Crossodactylus aeneus Müller, 1924 as a new junior synonym of C. gaudichaudii Duméril and Bibron, 1841 (Amphibia, Anura)
Abstract The nominal anuran species Crossodactylus gaudichaudii Dum éril and Bibron, 1841 and Crossodactylus aeneus Müller, 1924 are indistinguishable based on adult and larval morphology, being subject of taxonomic doubts. Here, we describe the karyotypes of C. gaudichaudii and C. aeneus, using classical and molecular cytogenetic markers. In addition, we used seq uences of the H1 mitochondrial DNA to infer their phylogenetic relationships by Maximum Likelihood (ML) and Maximum Parsimony (MP) approaches and species delimitation test (by bPTP approach). The karyotypic data do not differentiate C. gaudichaudii and C. aeneu...
Source: Genetics and Molecular Biology - March 22, 2021 Category: Genetics & Stem Cells Source Type: research
Emerging complexities and rising omission: Contrasts among socio-ecological contexts of infectious diseases, research and policy in Brazil
Abstract In this article, we explore elements that highlight the interdependent nature of demands for knowledge production and decision-making related to the appearance of emerging diseases. To this end, we refer to scientific production and current contextual evidence to verify situations mainly related to the Brazilian Amazon, which suffers systematic disturbances and is characterized as a possible source of pathogenic microorganisms. With the acceleration of the Anthropocene's environmental changes, socio-ecological instabilities and the possibility of the emergence of infectious diseases merge into a background of a ´...
Source: Genetics and Molecular Biology - March 17, 2021 Category: Genetics & Stem Cells Source Type: research
MASPs at the crossroad between the complement and the coagulation cascades - the case for COVID-19
Abstract Components of the complement system and atypical parameters of coagulation were reported in COVID-19 patients, as well as the exacerbation of the inflammation and coagulation activity. Mannose binding lectin (MBL)- associated serine proteases (MASPs) play an important role in viral recognition and subsequent activation of the lectin pathway of the complement system and blood coagulation, connecting both processes. Genetic variants of MASP1 and MASP2 genes are further associated with different levels and functional efficiency of their encoded proteins, modulating susceptibility and severity to diseases. Our review ...
Source: Genetics and Molecular Biology - March 17, 2021 Category: Genetics & Stem Cells Source Type: research
COVID-19 during pregnancy and adverse outcomes: Concerns and recommendations from The Brazilian Teratology Information Service
Abstract SARS-CoV-2 virus was first identified in the beginning of 2020 and has spread all over the world, causing the Coronavirus Disease 2019 (COVID-19) pandemic. The virus is a member of the Coronavirus family, which includes viruses that cause common cold, Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). MERS and SARS are known by causing adverse events in pregnancy. Considering that SARS-CoV-2 is a new infection agent, little is known about the risk of its infection to human embryo/fetal development. However, SARS and MERS were associated with negative outcomes, such as miscarriage...
Source: Genetics and Molecular Biology - March 11, 2021 Category: Genetics & Stem Cells Source Type: research
SARS-CoV-2 and COVID-19: A perspective from environmental virology
Abstract December 2019 marked the beginning of the current Coronavirus disease pandemic (COVID-19). Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) was identified as the causative agent of a viral pneumonia outbreak in Wuhan, Hubei Province, China. The alarming spread levels and clinical severity elevated the status of COVID-19 to the global pandemic by the World Health Organization. In 6 months, more than 25 million cases of infected people and more than 890,000 deaths by COVID-19 had been reported worldwide. The main goal of this review is to shed light upon the current COVID-19 epidemic situation in...
Source: Genetics and Molecular Biology - March 8, 2021 Category: Genetics & Stem Cells Source Type: research
Extreme phenotypes approach to investigate host genetics and COVID-19 outcomes
Abstract COVID-19 comprises clinical outcomes of SARS-CoV-2 infection and is highly heterogeneous, ranging from asymptomatic individuals to deceased young adults without comorbidities. There is growing evidence that host genetics play an important role in COVID-19 severity, including inborn errors of immunity, age-related inflammation and immunosenescence. Here we present a brief review on the known order of events from infection to severe system-wide disturbance due to COVID-19 and summarize potential candidate genes and pathways. Finally, we propose a strategy of subject ’ s ascertainment based on phenotypic extremes t...
Source: Genetics and Molecular Biology - March 1, 2021 Category: Genetics & Stem Cells Source Type: research
Challenges in estimating virus divergence times in short epidemic timescales with special reference to the evolution of SARS-CoV-2 pandemic
Abstract The estimation of evolutionary parameters provides essential information for designing public health policies. In short time intervals, however, nucleotide substitutions are ineffective to record all complexities of virus population dynamics. In this sense, the current SARS-CoV-2 pandemic poses a challenge for evolutionary analysis. We used computer simulation to evolve populations in scenarios of varying temporal intervals to evaluate the impact of the age of an epidemic on estimates of time and geography. Before estimating virus timescales, the shape of tree topologies can be used as a proxy to assess the effect...
Source: Genetics and Molecular Biology - February 8, 2021 Category: Genetics & Stem Cells Source Type: research
