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Table of contents: 2022

Research Article

This review deals with innovative concepts of evolution in vertebrates, such as epigenetic mechanisms and transgenerational inheritance. Evolutionary models based on data of fossil records, cytogenetics and molecular genetics are indicated. The 2R-model of vertebrate evolution is focalized as well as the epigenetic mechanisms of gene regulation and variability of polyploid anurans. It is known that science evolves by routes that are sometimes impelled by puzzling questions. The cytogenetic data here reported for Anurans brought some perplexing considerations involving fundamental concepts of neo-Darwinism regarding slow/fast evolution, ploidy, epigenetics, and transgenerational inheritance. Indeed, a growing body of evidence reveals that besides gene mutations, diversity may also be produced by epigenetic mutations of regulatory segments of DNA. Yet, an intriguing point to be explained is whether these types of mutations can promote evolution via transgenerational inheritance.

Genet. Mol. Res. 21(1): GMR18967
DOI: 10.4238/gmr18967
Research Article

It is known that mesothelin (MSLN) is overexpressed in some cancers, and that it plays a role in cell growth through Wnt family member 1 protein. Malignant transformation usually occurs with disruption of autoregulation of autophagy-related genes. We examined the effect of MSLN on survival and clinicopathological features in mesothelioma cases, as well as variations in genes associated with autophagy, invasion, apoptosis-related genes after siRNA-mediated MSLN silencing transfection in a mesothelioma cell line (SPC212). MSLN expression was analyzed, immunohistochemically, in formalin-fixed paraffin-embedded 60 mesothelioma cases. MSLN expression was categorized by median MSLN histoscores as low (L), high (H). The correlation between the levels of MSLN expression, clinicopathological features, and survival was determined in mesothelioma cases. The siRNA-mediated MSLN incubated SPC212 cells were transfected and compared to negative control siRNAs. mRNA levels were determined for autophagy, invasion, and apoptosis related-genes with RT-PCR, and western blotting in SPC212 cells after MSLN silencing.  All of the cases were immunoreactive for MSLN expression. H-MSLN was associated with a favorable prognosis according to Kaplan-Meier survival analysis, but Cox regression analysis revealed that only stage was a significant independent factor for estimating survival. MSLN overexpression was significantly higher in early-stage, mesothelioma cases without nodal involvement. Significant silencing in MSLN was found (87.5%) after siRNA applications. Apoptosis and autophagy were upregulated by increasing apoptosis-related genes, BAK1, BAX, CASP1-7, and autophagy-related genes, ATG2, ATG16L1. Cell proliferation was knocked down predominantly by inhibiting the invasion-related genes, MMP1, 10, 11, 13, in SPC212 cell lines. MSLN silencing was determined to significantly increase CASP3, but did not change LC3 in western blotting, respectively. In conclusion, siRNA-mediated silencing MSLN can promote apoptosis, autophagy, and also partially inhibit proliferation. We suggest that MSLN can serve as a potential therapeutic target in mesothelioma.

Genet. Mol. Res. 21(1): GMR18955
DOI: 10.4238/gmr18955
Research Article

It is essential that the genetic variability of preserved accessions germplasm banks be evaluated and quantified, which allows, for example, the detection of duplicates, generating more reliable data, especially for groups of plants that have a wide genetic variability, as in the case of the Capsicum genus. . We examined the DNA from the leaves of nine accessions of Capsicum spp . from the Federal University of Maranhão Germplasm Bank. Amplification was performed using 78 microsatellite primers previously described as potential molecular markers for Capsicum accessions. Thirty-three microsatellite primers produced amplification products, seven of which were polymorphic and used to investigate genetic variability among nine accessions. The proportion of polymorphic loci in pepper accessions was estimated at 21%. A mean of 2.28 alleles was detected per polymorphic locus and the number of alleles ranged from 1 to 3. The highest effective number of alleles was 1.62, and the highest values of mean observed heterozygosity (Ho) and Shannon's diversity index (I) were 0.533 and 0.421, respectively. Private alleles were detected in two accessions: UFMA17 and UFMA35. The highest Ho value was found in the UFMA10 accession, whereas the lowest value was recorded in the UFMA35 accession. Fixation indices (FST) indicated that 65% of the total allele frequency variation occurred within the analyzed loci. The polymorphism information content ranged from 0.011 to 0.354. Clustering of samples based on Nei's genetic distance matrix revealed the formation of three genetically distinct groups that allowed identifying genetically distinct groups based on SSR markers and discriminating the most closely related accessions of Capsicum spp. Neighbor-joining cluster analysis and PCoA allowed identifying genetically distinct groups based on SSR markers and discriminating the most closely related accessions of Capsicum spp.



Genet. Mol. Res. 21(1): GMR18953
DOI: 10.4238/gmr18953