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Gonsales, M. C.

Publications and source records attributed to Gonsales, M. C..

2 recordsLinked to original sources

An optimized protocol for the creation of constructs expressing sodium channel subunits to be used in functional studies of genetic epilepsies

BackgroundWe aim to develop a method for cloning highly unstable plasmids encoding sodium channel subunits expressed in the brain. MethodNEB Stable competent cells (NSCC) were transformed with the native plasmid. After purification, plasmids with the expected profile of enzymatic digestion were sequenced. Finally, mutant linear plasmids (MLP) created by site-directed mutagenesis were used to transform NSCC. ResultsWe found that choosing a suitable host for transformation and subcloning, the controlled temperature during cell growth, and a small volume of Luria Bertani (LB) medium allowed the generation of plasmids without undesirable mutations or structural alterations. Comparison with existing methodAt present, there is little information on a detailed method for cloning plasmids carrying the SCN1A gene. Using the method proposed here, we observed increased cell growth and precision in the sequence of the obtained plasmids. ConclusionWe have developed an optimized strategy for replicating unstable plasmids using NSCC with an appropriate volume of culture medium and an adequate temperature in the cloning and subcloning phases. We have also demonstrated how to create the desired plasmid constructs by using site-directed mutagenesis. We expect that our protocol will assist investigators interested in functional studies of sodium channels expressed in the brain.

molecular biology↗

Genetic variability in COVID-19-related genes in the Brazilian population

SARS-CoV-2 employs the angiotensin-converting enzyme 2 (ACE2) receptor and the transmembrane serine protease (TMPRSS2) to infect human lung cells. Previous studies have suggested that different host genetic backgrounds in ACE2 and TMPRSS2 could contribute to differences in the rate of infection or severity of COVID-19. Recent studies also showed that variants in 15 genes related to type I interferon immunity to influenza virus could predispose to life-threatening COVID-19 pneumonia. Additional genes (SLC6A20, LZTFL1, CCR9, FYCO1, CXCR6, XCR1, IL6, CTSL, ABO, and FURIN) and HLA alleles have also been implicated in response to infection with SARS-CoV-2. Currently, Brazil has recorded the third-highest number of COVID-19 patients worldwide. We aim to investigate the genetic variation present in COVID-19-related genes in the Brazilian population. We analysed 27 candidate genes and HLA alleles in 954 admixed Brazilian exomes. We used the information available in two public databases (http://www.bipmed.org and http://abraom.ib.usp.br/), and additional exomes from individuals born in southeast Brazil, the region with the highest number of COVID-19 patients in the country. Variant allele frequencies were compared with the 1000 Genomes Project phase 3 (1KGP) and the gnomAD databases. We found 395 non-synonymous variants; of these, 325 were also found in the 1000 Genome Project phase 3 (1KGP) and/or gnomAD. Six of these variants were previously reported as putatively influencing the rate of infection or clinical prognosis for COVID-19. The remaining 70 variants were identified exclusively in the Brazilian sample, with a mean allele frequency of 0.0025. In silico prediction of the impact in protein function revealed that three of these rare variants were pathogenic. Furthermore, we identified HLA alleles that were previously associated with COVID-19 response at loci DQB1 and DRB1. Our results showed genetic variability common to other populations, but also rare and ultra-rare variants exclusively found in the Brazilian population. These findings could potentially lead to differences in the rate of infection or response to infection by SARS-CoV-2 and should be further investigated in patients with the disease.

genetics↗