RESUMEN
The World Health Organization characterized COVID-19 as a pandemic in March 2020, the second pandemic of the twenty-first century. Expanding virus populations, such as that of SARS-CoV-2, accumulate a number of narrowly shared polymorphisms, imposing a confounding effect on traditional clustering methods. In this context, approaches that reduce the complexity of the sequence space occupied by the SARS-CoV-2 population are necessary for robust clustering. Here, we propose subdividing the global SARS-CoV-2 population into six well-defined subtypes and 10 poorly represented genotypes named tentative subtypes by focusing on the widely shared polymorphisms in nonstructural (nsp3, nsp4, nsp6, nsp12, nsp13 and nsp14) cistrons and structural (spike and nucleocapsid) and accessory (ORF8) genes. The six subtypes and the additional genotypes showed amino acid replacements that might have phenotypic implications. Notably, three mutations (one of them in the Spike protein) were responsible for the geographical segregation of subtypes. We hypothesize that the virus subtypes detected in this study are records of the early stages of SARS-CoV-2 diversification that were randomly sampled to compose the virus populations around the world. The genetic structure determined for the SARS-CoV-2 population provides substantial guidelines for maximizing the effectiveness of trials for testing candidate vaccines or drugs.
Asunto(s)
Betacoronavirus/genética , Polimorfismo Genético , Betacoronavirus/clasificación , Betacoronavirus/aislamiento & purificación , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/patología , Infecciones por Coronavirus/virología , Proteínas de la Nucleocápside de Coronavirus , Genotipo , Humanos , Proteínas de la Nucleocápside/genética , Pandemias , Fosfoproteínas , Filogenia , Neumonía Viral/epidemiología , Neumonía Viral/patología , Neumonía Viral/virología , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/genética , Proteínas no Estructurales Virales/genética , Proteínas Virales/genéticaRESUMEN
Mitochondrial inner membrane uncoupling proteins (UCP) catalyze a proton conductance that dissipates the proton electrochemical gradient established by the respiratory chain, thus affecting the yield of ATP synthesis. UCPs are involved in mitochondrial energy flow regulation and have been implicated in oxidative stress tolerance. Based on the global gene expression profiling datasets available for Arabidopsis thaliana, in this review we discuss the regulation of UCP gene expression during development and in response to stress, and provide interesting insights on the possible existence of epigenetic regulation of UCP expression.
Asunto(s)
Arabidopsis/metabolismo , Epigénesis Genética/fisiología , Regulación del Desarrollo de la Expresión Génica/fisiología , Regulación de la Expresión Génica de las Plantas/fisiología , Canales Iónicos/metabolismo , Proteínas Mitocondriales/metabolismo , Estrés Fisiológico/fisiología , Arabidopsis/crecimiento & desarrollo , Biología Computacional/métodos , Epigénesis Genética/genética , Regulación del Desarrollo de la Expresión Génica/genética , Regulación de la Expresión Génica de las Plantas/genética , Regiones Promotoras Genéticas/genética , Estrés Fisiológico/genética , Proteína Desacopladora 1RESUMEN
Post-transcriptional gene silencing (PTGS) is a conserved surveillance mechanism that identifies and cleaves double-stranded RNA molecules and their cellular cognate transcripts. The RNA silencing response is actually used as a powerful technique (named RNA interference) for potent and specific inhibition of gene expression in several organisms. To identify gene products in Eucalyptus sharing similarities with enzymes involved in the PTGS pathway, we queried the expressed sequence tag database of the Brazilian Eucalyptus Genome Sequence Project Consortium (FORESTs) with the amino acid sequences of known PTGS-related proteins. Among twenty-six prospected genes, our search detected fifteen assembled sequences encoding products presenting high level of similarity (E value < 10-40) to proteins involved in PTGS in plants and other organisms. We conclude that most of the genes known to be involved in the PTGS pathway are represented in the FORESTs database