Genetics and Molecular Biology最新文献

Waterlogging stress is an important abiotic stress that adversely affects maize growth and yield. The mechanism regulating the early stage of the maize response to waterlogging stress is largely unknown. In this study, CM37 and cmh15 seedlings were treated with waterlogging stress and then examined in terms of their physiological changes. The results indicated that inbred line cmh15 is more tolerant to waterlogging stress and less susceptible to peroxide-based damages than CM37. The RNA sequencing analysis identified 1,359 down-regulated genes and 830 up-regulated genes in the waterlogging-treated cmh15 plants (relative to the corresponding control levels). According to the Gene Ontology analysis for the differentially expressed genes (DEGs), some important terms were identified which may play important roles in the response to waterlogging stress. Moreover, enriched Kyoto Encyclopedia of Genes and Genomes pathways were also identified for the DEGs. Furthermore, the substantial changes in the expression of 36 key transcription factors may be closely related to the maize in response to waterlogging stress. This study offers important insights into the mechanism in regulating maize tolerance to waterlogging stress, with important foundations for future research.

Alcohol Use Disorder (AUD) is a highly prevalent condition worldwide that produces a wide range of pathophysiological consequences, with a critical impact on health and social issues. Alcohol influences gene expression through epigenetic changes mainly through DNA methylation. In this sense, levels of 5-methylcytosine (5-mC), namely Global DNA methylation (GMe), which can be influenced by environmental and hormonal effects, represent a putative biological mechanism underlying alcohol effects. Our aim was to investigate the influence of AUD diagnosis and alcohol patterns (i.e., years of addiction, use in the last 30 days, and alcohol severity) on GMe levels. The sample consisted of 256 men diagnosed with AUD and 361 men without AUD. DNA samples from peripheral blood were used to assess GMe levels, measured through the levels of 5-mC using high-performance liquid chromatography. Results from multiple linear regression analysis indicated that the presence of AUD was associated with lower GMe levels (beta=-0.155, p=0.011). Other alcohol-related outcomes were not associated with DNA methylation. Our findings are consistent with the hypothesis that the impact of chronic and heavy alcohol use in GMe could be a potential mechanism mediating the multiple organ damages related to AUD.

Paenibacillus sonchi genomovar Riograndensis SBR5T is a plant growth-promoting rhizobacterium (PGPR) isolated in the Brazilian state of Rio Grande do Sul from the rhizosphere of Triticum aestivum. It fixes nitrogen, produces siderophores as well as the phytohormone indole-3-acetic acid, solubilizes phosphate and displays antagonist activity against Listeria monocytogenes and Pectobacterium carotovorum. Comprehensive omics analysis and the development of genetic tools are key to characterizing and engineering such non-model microorganisms. Therefore, the complete genome of SBR5T was sequenced, and shown to encode 6,705 proteins, 87 tRNAs, and 27 rRNAs and it enabled a landscape transcriptome analysis that unveiled conserved transcriptional and translational patterns and characterized operon structures and riboswitches. The pangenome of P. sonchi species is open with a stable core pangenome. At the same time, the analysis of genes coding for nitrogenases revealed that the trait of nitrogen fixation is sparse within the Paenibacillaceae family and the presence of Fe-only nitrogenase in the P. sonchi group was exclusive to SBR5T. The development of genetic tools for SBR5T enabled genetic transformation, plasmid construction for constitutive and inducible gene expression, and gene repression using the CRISPRi system. Altogether, the work with P. sonchi can guide the study of non-model bacteria with economic potential.

Staphylococcus aureus is a frequent cause of infections worldwide. Methicillin-resistant S. aureus (MRSA) is one of the main causes of Gram-positive infections, and methicillin-susceptible strains (MSSA) primarily colonize and infect community hosts. Multiple virulence factors are involved, with toxins playing a significant role in several diseases. In this study, we assess the prevalence of toxin genes in 89 S. aureus clinical isolates (31 MRSA and 58 MSSA). We evaluated the discriminatory power of the association of internal transcribed spacer-PCR (ITS-PCR) and 3'- end coa gene ( coa-PCR) when compared with other more commonly used and costly techniques. The isolates showed a high level of genetic diversity, and toxins were found in all the isolates. While most toxin classes displayed no statistically significant correlations and were equally distributed in isolates regardless of their resistance status, classic enterotoxins ( sea-see) showed a positive correlation with MSSA isolates. The combination of coa-PCR with ITS-PCR showed a discriminatory index of 0.84, discriminating 22 genotypes that agree with previously determined data by PFGE and MLST. This association between the two PCR-based methods suggests that they can be useful for an initial molecular epidemiological investigation of S. aureus in hospitals, providing significant information while requiring fewer resources.

Oculocutaneous albinism (OCA) is a heterogeneous group of genetic disorders involving deficiencies in melanin biosynthesis, with consequent skin, hair, and eye hypopigmentation. The world prevalence is estimated at 1/17,000, but there is high variability among populations. The affected individuals, besides clinical complications, can suffer from discrimination. The Brazilian population is highly admixed, with isolated and inbred communities. Previous reports indicated the presence of diverse isolated communities with a high prevalence of OCA in Brazil. The present work sought to review and characterize clusters of albinism in this country based on scientific literature search, newspapers, and websites. We identified and characterized 18 clusters, 13 confirmed by scientific studies. Seven clusters are in the Northeast region, with predominant African ancestry, and seven others in indigenous communities, particularly among the Kaingaing in South Brazil. Isolation and inbreeding associated with founder effects seem to be the most plausible explanation. Molecular studies and clinical classification are still limited. Their localization in deprived regions with poor infrastructure makes them particularly vulnerable to the social and clinical consequences of lacking melanin. We reinforce the need for a tailored approach to these communities, including appropriate medical care, social support, and genetic counselling.

Characterization of specific birth defects is essential for conducting scientific investigations, care and therapeutic strategies. This article describes demographic, clinical and genetic aspects, risk factors and access to treatment of Brazilian patients with orofacial clefts registered in a specialized collaborative center of the Brazilian Database on Craniofacial Anomalies (BDCA). We interviewed 70 individuals with typical orofacial clefts using a standard instrument from the database and subjected them to genetic testing. The patients were grouped as syndromic and non-syndromic. The majority of individuals were of lower middle class, native ancestry and syndromic. There was a significant difference in the type of clefts regarding gender. There was no significant difference between bilateral and unilateral, between the side affected, right and left, or familial recurrence related to type of oral cleft. The risk factor familial recurrence was significantly higher among non-syndromic cases. Etiological factors were identified or suggested in 62.5% of the syndromic cases. There was a delay in diagnosis and in access to treatment in most cases. We concluded that gender, native ancestry and low family income represent risk factors. Furthermore, the distribution by cleft types and gender is similar to previous studies. The results can guide scientific investigations and care policies.

The LEF1/TCF transcription factor family is related to the development of diverse tissue types, including the mammary tissue, and dysregulation of its expression and function has been described to favor breast tumorigenesis. However, the clinical and biological relevance of this gene family in breast cancer is still poorly understood. Here, we used bioinformatics approaches aiming to reduce this gap. We investigated its expression patterns in molecular and immune breast cancer subtypes; its correlation with immune cell infiltration, and its prognostic values in predicting outcomes. Also, through regulons construction, we determined the genes whose expression is influenced by these transcription factors, and the pathways in which they are involved. We found that LEF1 and TCF3 are over-expressed in breast tumors regarding non-tumor samples, while TCF4 and TCF7 are down-expressed, with the gene's methylation status being associated with its expression dysregulation. All four transcription factors presented significance at the diagnostic and prognostic levels. LEF1, TCF4, and TCF7 presented a significant correlation with immune cell infiltration, being associated with the immune subtypes of less favorable outcomes. Altogether, this research contributes to a more accurate understanding of the expression and clinical and biomarker significance of the LEF1/TCF transcription factors in breast cancer.

The Subcortical Maternal Complex (SCMC) is composed of maternally encoded proteins required for the early stages of embryo development. Here we aimed to investigate the expression profile of the genes that encode the individual members of the SCMC in human reproductive failures. To accomplish that, we selected three datasets in the Gene Expression Omnibus repository for differential gene expression (DGE) analysis, comprising human endometrial and placental tissues of patients with recurrent implantation failure (RIF) or recurrent pregnancy loss (RPL). The SCMC genes KHDC3L, NLRP2, NLRP4, NLRP5, OOEP, PADI6, TLE6, and ZBED3 were included in the DGE analysis, as well as CFL1 and CFL2 that connect the SCMC with the actin cytoskeleton. Additionally, differential co-expression analysis and systems biology analysis of gene-gene co-expression were performed for KHDC3L, NLRP5, OOEP, and TLE6, demonstrating gene pairs differentially correlated under the two conditions, and the co-expression with genes involved in immune response, cell cycle, DNA damage repair, embryo development, and male reproduction. Compared to control groups, NLRP5 demonstrated upregulation in the endometrium of RIF patients, and KHDC3L was upregulated in the fetal placental tissue of RPL patients, shedding light on the importance of considering SCMC genes in reproductive failures.

Spinal muscular atrophy (SMA) is considered one of the most common autosomal recessive disorders, with an estimated incidence of 1 in 10,000 live births. Testing for SMA has been recommended for inclusion in neonatal screening (NBS) panels since there are several therapies available and there is evidence of greater efficacy when introduced in the pre/early symptomatic phases. In Brazil, the National Neonatal Screening Program tests for six diseases, with a new law issued in 2021 stating that it should incorporate more diseases, including SMA. In the present study, dried blood spot (DBS) samples collected by the Reference Services of Neonatal Screening of RS and SP, to perform the conventional test were also screened for SMA, using real-time PCR, with SALSA MC002 technique. A total of 40,000 samples were analyzed, enabling the identification of four positive cases of SMA, that were confirmed by MLPA. Considering our sampling, Brazil seems to have an incidence comparable to the described in other regions. This work demonstrated that the use of the MC002 technique in samples routinely collected for the conventional NBS program is suitable to screen for SMA in our conditions and can be included in the expansion of the neonatal screening programs.

Mucolipidosis II and III (MLII and MLIII) are autosomal recessive diseases caused by pathogenic variants in GNPTAB and GNPTG genes that lead to defects in GlcNAc-1-phosphotransferase. This enzyme adds mannose 6-phosphate residues to lysosomal hydrolases, which allows enzymes to enter lysosomes. Defective GlcNAc-1-phosphotransferase causes substrate accumulation and inflammation. These diseases have no treatment, and we hypothesized that the use of substrate reduction therapy and immunomodulation may be beneficial at the cell level and as a future therapeutic approach. Fibroblasts from two patients with MLIII alpha/beta and 2 patients with MLIII gamma as well as from one healthy control were treated with 10 µM miglustat, 20 µM genistein, and 20 µM thalidomide independently. ELISA assay and confocal immunofluorescence microscopy were used to evaluate the presence of heparan sulfate (HS) and the impact on substrate accumulation. ELISA assay showed HS reduction in all patients with the different treatments used (p=0.05). HS reduction was also observed by immunofluorescence microscopy. Our study produced encouraging results, since the reduction in substrate accumulation, even partial, may offer benefits to the phenotype of patients with inborn errors of metabolism.