Transposable elements (TEs) are common mobile genetic elements comprising several classes and making up the majority of eukaryotic genomes. The movement and accumulation of TEs has been a major force shaping the genes and genomes of most organisms. Most eukaryotic genomes are dominated by retrotransposons and minimal DNA transposon accumulation. The ‘copy and paste’ lifecycle of replicative transposition produces new genome insertions without excising the original element. Horizontal TE transfer among lineages is rare. TEs represent a reservoir of potential genomic instability and RNA-level toxicity. Many TEs appear static and nonfunctional, but some are capable of replicating and mobilising to new positions, and somatic transposition events have been observed. The overall structure of retrotransposons and the domains responsible for the phases of their replication are highly conserved in all eukaryotes. TEs are important drivers of species diversity and exhibit great variety in their structure, size and transposition mechanisms, making them important putative actors in evolution. Because TEs are abundant in plant genomes, various applications have been developed to exploit polymorphisms in TE insertion patterns, including conventional or anchored PCR, and quantitative or digital PCR with primers for the 5' or 3' junction. Alternatively, the retrotransposon junction can be mapped using high-throughput next-generation sequencing and bioinformatics. With these applications, TE insertions can be rapidly, easily and accurately identified, or new TE insertions can be found. This review provides an overview of the TE-based applications developed for plant species and assesses the contributions of TEs to the analysis of plants’ genetic diversity.

Cultivated grapevine (Vitis vinifera L. ssp. sativa D.C.) is one of the oldest agricultural crops, each variety comprising an array of clones obtained by vegetative propagation from a selected vine grown from a single seedling. Most clones within a variety are identical, but some show a different form of accession, giving rise to new divergent phenotypes. Understanding the associations among the genotypes within a variety is crucial to efficient management and effective grapevine improvement. Inter-primer binding-site (iPBS) markers may aid in determining the new clones inside closely related genotypes. Following this idea, iPBS markers were used to assess the genetic variation of 33 grapevine genotypes collected from Russia. We used molecular markers to identify the differences among and within five grapevine clonal populations and analysed the variation, using clustering and statistical approaches. Four of a total of 30 PBS primers were selected, based on amplification efficiency. Polymerase chain reaction (PCR) with PBS primers resulted in a total of 1412 bands ranging from 300 to 6000 bp, with a polymorphism ratio of 44%, ranging from 58 to 75 bands per group. In total, were identified seven private bands in 33 genotypes. Results of molecular variance analysis showed that 40% of the total variation was observed within groups and only 60% between groups. Cluster analysis clearly showed that grapevine genotypes are highly divergent and possess abundant genetic diversities. The iPBS PCR-based genome fingerprinting technology used in this study effectively differentiated genotypes into five grapevine groups and indicated that iPBS markers are useful tools for clonal selection. The number of differences between clones was sufficient to identify them as separate clones of studied varieties containing unique mutations. Our previous phenotypic and phenological studies have confirmed that these genotypes differ from those of maternal plants. This work emphasized the need for a better understanding of the genotypic differences among closely related varieties of grapevine and has implications for the management of its selection processes.

We developed a comprehensive multiplexed set of primers adapted for the Oxford Nanopore Rapid Barcoding library kit that allows universal SARS-CoV-2 genome sequencing. This primer set is designed to set up any variants of the primers pool for whole-genome sequencing of SARS-CoV-2 using single- or double-tiled amplicons from 1.2 to 4.8 kb with the Oxford Nanopore. This multiplexed set of primers is also applicable for tasks like targeted SARS-CoV-2 genome sequencing. We proposed here an optimized protocol to synthesize cDNA using Maxima H Minus Reverse Transcriptase with a set of SARS-CoV-2 specific primers, which has high yields of cDNA template for RNA and is capable of long-length cDNA synthesis from a wide range of RNA amounts and quality. The proposed protocol allows whole-genome sequencing of the SARS-CoV-2 virus with tiled amplicons up to 4.8 kb on low-titer virus samples and even where RNA degradation has occurred. This protocol reduces the time and cost from RNA to genome sequence compared to the Midnight multiplex PCR method for SARS-CoV-2 genome sequencing using the Oxford Nanopore.

Background: Kazakhstan has a high burden of multidrug-resistant tuberculosis in the Central Asian region. This study aimed to perform genomic characterization of Mycobacterium tuberculosis strains obtained from Kazakhstani patients with pre-extensively drug-resistant tuberculosis diagnosed in Kazakhstan. Methods: Whole-genome sequencing was performed on 10 pre-extensively drug-resistant M. tuberculosis strains from different regions of Kazakhstan. All strains had high-confidence resistance mutations according to the resistance grading system previously established by the World Health Organization. The genome analysis was performed using TB-Profiler, Mykrobe, CASTB, and ResFinder. Results: Valuable information for understanding the genetic diversity of tuberculosis in Kazakhstan can also be obtained from whole-genome sequencing. The results from the Phenotypic Drug Susceptibility Testing (DST) of bacterial strains were found to be consistent with the drug resistance information obtained from genomic data that characterized all isolates as pre-XDR. This information can help in developing targeted prevention and control strategies based on the local epidemiology of tuberculosis. Furthermore, the data obtained from whole-genome sequencing can help in tracing the transmission pathways of tuberculosis and facilitating early detection of outbreaks. Conclusions: The results from whole-genome sequencing of tuberculosis clinical samples in Kazakhstan provide important insights into the drug resistance patterns and genetic diversity of tuberculosis in the country. These results can contribute to the improvement of tuberculosis control and management programs in Kazakhstan.

Bacteroides fragilis is one of the most important human anaerobic pathogens often found in various clinical infections. The purpose of this study was to determine the susceptibility of a B. fragilis clinical strain (BFR_KZ01) from Kazakhstan to the most commonly used anti-anaerobic drugs at the local level and to detect genes associated with resistance to these antibiotics. Species identification of the bacterial isolate was performed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) and 16S rRNA gene sequencing. Susceptibility to broad-spectrum antibiotics (metronidazole, meropenem, ciprofloxacin, clindamycin and tetracycline) most commonly used for the treatment of intra-abdominal infections (IAIs) was determined. Mass spectra groups essential for identifying cfiA-positive strains among clinical isolates were studied using ClinProTools 3.0.22 software. An Ion Torrent PGM™ platform was used for whole-genome sequencing (WGS) of the studied isolate. The resulting WGS data of strain BFR_KZ01 was submitted to GenBank. In total, 5300 coding sequences (CDSs) and 69 RNA genes were determined. Analysis of the whole-genome data revealed that the studied strain harbours cfiA, nimB, tetQ and gyrA genes conferring resistance to key drugs used in treatment of the IAIs. MALDI-TOF/MS analysis assigned strain BFR_KZ01 to Group II (cfiA-positive); however, BFR_KZ01 was phenotypically sensitive to meropenem (mean MIC, 1.3 mg/L). Determinants of drug resistance in strain BFR_KZ01 were identified. It was revealed that B. fragilis strain BFR_KZ01 from Kazakhstan is multidrug-resistant since it carries nimB, tetQ and gyrA genes conferring resistance to metronidazole, tetracycline and ciprofloxacin.

Aeromonas spp. are opportunistic pathogens that are widely distributed in water sources, with several species being associated with fish and human diseases. We have previously identified an Aeromonas AB005 isolate from diseased Acipencer baerii. This isolate was identified as A. hydrophila based on the 16S rRNA and gyrB gene sequences. However, this novel strain does not produce indole and tested negative for ornithine decarboxylase and d-xylose fermentation—differences that set it apart from typical A. hydrophila strains. In the present study, this strain was subjected to whole-genome sequencing and compared with the genomes of the type strain (Aeromonas hydrophila ATCC 7966^T) and other Aeromonas spp. Comprehensive genome analysis suggests that AB005 represents a distinct species within the genus. The draft genome of the AB005 strain comprises 4,780,815 base pairs with a GC content of 61.2% and contains 6104 predicted protein-coding sequences along with numerous genes implicated in antibiotic resistance. The core/pan-genome analysis reveals extensive genetic diversity, indicative of a dynamic genomic structure. These findings collectively underscore the taxonomic distinction of the AB005 strain as a novel species and highlight its potential pathogenic implications in aquaculture and public health settings.