Biology subjects

Potapova, N.

Publications and source records attributed to Potapova, N..

4 recordsLinked to original sources

bioRxiv2025

The Impact of Exogenous Mutagens on Human Mitochondrial DNA Ploidy: Analysis of Changes and Possible Protective Mechanisms.

Mitochondrial ploidy -- the relative copy number of mitochondrial DNA per mitochondrion -- may serve as an early marker of cellular stress and a potential signal of genotoxic damage. In this study, we investigate the dynamics of mitochondrial ploidy in iPSC cells in vitro following exposure to a range of chemical mutagens. Using a qPCR-based method allowing accurate quantification of mitochondrial DNA and mitochondria number, we reveal distinct changes in mitochondrial ploidy that correlate with the genotoxic impact of specific agents. Among the mutagens tested, MX, benzidine, cyclophosphamide, hydrogen peroxide, semustine and nickel (II) chloride induced the most pronounced alterations in mitochondrial DNA content and organization. These findings suggest that mitochondrial ploidy can be used as a sensitive molecular indicator of mutagenic stress, potentially reflecting mitochondrial genome maintenance and organelle adaptation mechanisms.

bioinformatics↗

bioRxiv2025

Structural features of the amino acid sequences of Chromista nucleolin-like proteins

Nucleolins are multifunctional proteins localized in the centrosome and nucleus and involved in the processes of microtubule nucleation. Their structure is highly conserved in organisms that are evolutionarily distant from each other. The phylogeny of the kingdom Chromista was supported by marker genes, cell morphology and cytoskeletal features. In this study we identified general patterns of the nucleolin protein structure characteristic of this group - the structure of the N-terminal and central domains, including bipartite sequences that ensure nuclear localization, as well as RNA recognition motifs. We also noted features in the primary structure of these proteins, which may affect the conformation of the protein molecule. Each of the six clades identified during phylogenetic reconstruction has structural features of the N-terminal domains, bipartite nuclear localization sequences and sequences of RNA recognition motifs. The features we described allow us to classify the studied nucleolin sequences of Chromista as nucleolin-like proteins. In this study, we described for the first time the structure of nucleolin-like proteins in Chromista.

molecular biology↗

bioRxiv2020

Convergent adaptation in mitochondria of phylogenetically distant birds: does it exist?

In a wide range of taxa, proteins encoded by mitochondrial genomes are involved in adaptation to lifestyle that requires oxygen starvation or elevation of metabolism rate. It remains poorly understood to what extent adaptation to similar conditions is associated with parallel changes in these proteins. We search for genetic signal of parallel or convergent evolution in recurrent molecular adaptation to high altitude, migration, diving, wintering, unusual flight abilities, or loss of flight in mitochondrial genomes of birds. Developing on previous work, we design an approach for detection of recurrent coincident changes in genotype and phenotype, indicative of an association between the two. We describe a number of candidate sites involved in recurrent adaptation in ND genes. However, we find that the majority of convergence events can be explained by random coincidences without invoking adaptation.

bioinformatics↗

bioRxiv2017

Are Nonsense Alleles of Drosophila melanogaster Genes under Any Selection?

A gene which carries a bona fide loss-of-function mutation effectively becomes a functionless pseudogene, free from selective constraint. However, there is a number of molecular mechanisms that may lead to at least a partial preservation of the function of genes carrying even drastic alleles. We performed a direct measurement of the strength of negative selection acting on nonsense alleles of protein-coding genes in the Zambian population of Drosophila melanogaster. Within those exons that carry nonsense mutations, negative selection, assayed by the ratio of missense over synonymous nucleotide diversity levels, appears to be absent, consistent with total loss of function. In other exons of nonsense alleles, negative selection was deeply relaxed but likely not completely absent, and the per site number of missense alleles declined significantly with the distance from the premature stop codon. This pattern may be due to alternative splicing which preserves function of some isoforms of nonsense alleles of genes.

evolutionary biology↗