Search Results (64)

Background/Objectives: Chronic lymphocytic leukemia (CLL) is a hematologic malignancy characterized by uncontrolled accumulation of B lymphocytes. A key feature of CLL is the presence of genetic aberrations, particularly alterations of chromosome 17, such as deletion of 17q and/or mutations in the TP53 gene. Since these abnormalities are highly relevant for therapeutic decision-making, assessment of TP53 mutational status is strongly recommended in routine diagnostics. This study aimed to evaluate the reliability of TP53 sequencing results depending on the type of DNA sample analyzed. Methods: DNA was isolated from two different sample types of the same patient: mononuclear cells (CLL1) and purified CD19+ cells (CLL2). The entire coding region of TP53 (exons 2–11), including splice sites (+/− 10 bp), was analyzed using capture-based next-generation sequencing (NGS). Reads were aligned to the GRCh37/hg19 reference genome, and variants were interpreted using DRAGEN Enrichment (Illumina) and Franklin (QIAGEN). Results: In sample CLL1, the NM_000546.6:c.626_627del mutation (Tier I) was identified with a variant allele frequency (VAF) of 57.06%. The same mutation was confirmed in CLL2, but with a higher VAF of 94.78%. Importantly, an additional Tier I mutation (NM_000546.6:c.825_826del) was detected exclusively in CLL2 at a VAF of 1.59%. Both findings met the required sequencing depth as well as coverage per sample, confirming their validity. Conclusions: The study demonstrates that inadequate starting material for DNA isolation may mask low-frequency TP53 mutations, resulting in false-negative results. Accurate detection requires ensuring sufficient CD19+ cell content, which is critical for reliable diagnostics and supports personalized treatment approaches in CLL. Full article

Background: In 2015, it was discovered that mutations in the TEX11 gene are associated with azoospermia in general and meiotic maturation arrest in particular. TEX11 is a component of the ZZS complex (comprising Zip2-, Zip4- and Spo16 and originally described in Saccharomyces cerevisiae). During meiosis, this complex is required for the promotion of double-strand break (DSB) repair and thus the maintenance of genomic integrity. Since the initial discovery, several variants and deletions in TEX11 have been reported in patients with spermatogenesis defects. However, many of these new variants have not been functionally validated, which makes it difficult to confirm their direct impact on meiosis. The exonic in-frame deletion TEX11-c.652del237bp has been recurrently identified in infertile men. However, mice models carrying this deletion remain fertile—suggesting that these models may not faithfully replicate human meiotic phenotypes. To address this discrepancy, we functionally validated the TEX11-c.652del237bp variant in vitro. Methods: After amplification in Escherichia Coli DH5α, the pIRES2-EGFP plasmid containing either the wild-type TEX11 sequence or the TEX11-c.652del237bp sequence was transfected into the HEK293 human embryonic kidney cell line. qPCR and Western blot analyses were then used to evaluate the presence and expression levels of TEX11 mRNA and TEX11 protein. Results: The qPCR and Western blot analyses showed that truncated mRNA and protein were produced in cells transfected with the c.652del237bp variant. Hence, the deletion probably leads to the transcription and translation of TEX11 in human testis. Furthermore, in silico modeling suggested that the deletion does not have a significant impact on the ZZS complex. Conclusions: Our in vitro and in silico data demonstrate that the c.652del237bp in-frame deletion results in a truncated TEX11 protein and thus question the deletion’s pathogenic role in human meiosis. However, the absence of a meiotic phenotype in the corresponding mouse model is suggestive of species-specific differences in TEX11 endogenous function. Further studies (such as co-immunoprecipitation experiments with other ZZS complex proteins) are needed to fully assess the functional impact of TEX11-c.652del237bp. These experiments might also provide novel insights into the specific role of the TEX11 SPO22 domain in human spermatogenesis. Full article

Background/Objectives: Staphylococcus aureus isolates from humans and horses of the equine-associated clonal complexes (CCs) CC1 and CC1660 were comparatively investigated for their genomic relationships. Methods: A total of 91 S. aureus isolates (64 human, 27 equine) were subjected to whole-genome sequencing (WGS), sequence analysis, and antimicrobial susceptibility testing. Results: WGS confirmed 75 CC1 and 16 CC1660 isolates, comprising nine sequence types (STs) in CC1 and four STs in CC1660. Ten spa types were present in CC1 and five in CC1660. In the arcC gene of three CC1 isolates, a 285 bp deletion was detected, and a nucleotide deletion causing a premature stop codon was found in one CC1660 isolate. Core genome (cg) MLST revealed a minimum difference of 1398/1492 alleles between the two CCs. All CC1 isolates harbored agr group III and capsule type 8 alleles, whereas all CC1660 isolates had agr group II and capsule type 5 alleles. Antimicrobial susceptibility testing revealed 18 phenotypic and 19 genotypic resistance patterns. All isolates were susceptible to vancomycin, linezolid and quinupristin–dalfopristin. Several virulence genes were detected in different combinations. The equine leukocidin genes lukP/lukQ were found in 22 isolates from horses and 38 isolates from humans, of which 35 had confirmed contact with horses. No Panton–Valentine leukocidin genes were found. Three human CC1660 isolates carried the toxic shock syndrome toxin-1 gene tst-1. Conclusions: The analysis of the 91 isolates might suggest intra- and interspecies transmission among and between humans and horses, which should be monitored in the future. Full article

Gene editing enables a better understanding of protein functions. The genome of the protozoan parasite Entamoeba histolytica contains a 4500 bp DNA fragment comprising the ehcp112, ehadh, and ehrabb genes, which together form the V1 virulence locus. Studying these genes has been challenging due to the lack of suitable methodologies. Here, we report the first in vitro and in vivo knockout in E. histolytica (ehcp112 gene) using a modified CRISPR-Cas9 strategy and explore its effects on the other V1 locus genes. Confocal and transmission electron microscopy were used to detect the RNP pathway formed by the Cas9 enzyme and the crRNA–tracrRNA complex, from their entry into the trophozoites until their arrival at the nucleus and heterochromatin. Scanning electron microscopy revealed that the mutant cells (EhCP112-KO) were smaller, with fewer pseudopodia and plasma membrane depressions. DNA sequencing and RT-qPCR assays identified a four-base deletion in the ehcp112 gene in the mutant trophozoites. Western blot assays of EhCP112-KO extracts revealed the absence of the EhCP112 protein. While the EhCP112-KO lysates digested gelatin more efficiently than the HM1:IMSS extracts, their secreted products showed poor enzymatic activity. The ehcp112 knockout also affected the transcription of the ehadh and ehrabb genes, probably due to their genomic position. In conclusion, the implementation of the CRISPR-Cas9 strategy in E. histolytica evidenced the coordinated expression of the ehcp112 gene and the other members of the V1 locus. Full article

Uncoupling protein 2 (UCP2) plays an important role in normal cells because it mitigates the cytotoxic effect of reactive oxygen species (ROS). However, its overexpression in cancer cells is related to drug resistance and increased cell proliferation due to a decrease in ROS production. In this context, molecules that regulate or block UCP2 have potential as anticancer agents. (-)-Epicatechin, a flavonoid that inhibits cell proliferation, increases ROS, and induces apoptosis in cancerous cells, was evaluated for its effects on UCP2 gene expression. For this purpose, the real-time quantitative polymerase chain reaction (qRT–PCR) and Western blotting were performed in MDA-MB-231 and MCF-10A cells to determine the effects of (-)-epicatechin on UCP2 expression. Furthermore, the impact of (-)-epicatechin on cell viability was also determined. To analyze the transcriptional regulation of the UCP2 gene by (-)-epicatechin, a 5′-region of the human UCP2 gene (−2093/+297) was amplified, sequenced, cloned, and inserted into a reporter plasmid. To analyze the promoter activity and regulatory motif involved in the effects of (-)-epicatechin, several deletions of the UCP2 promoter were generated and transfected into MDA-MB-231 and MCF-10A cells. An electrophoretic mobility shift assay (EMSA) was carried out to detect the interaction between DNA and proteins involved in the effect of (-)-epicatechin. The increased expression of the UCP2 gene in MDA-MB-231 cells was decreased by (-)-epicatechin, and the opposite effect was observed in MCF-10A cells. The promoter region of the human UCP2 gene (−2093/+297) showed activity, which was decreased by (-)-epicatechin. A sequence of 117 bp located at position −109 b to +8 b has a fragment of 90 bp that is related to the (-)-epicatechin effect. Bioinformatics analysis and EMSA of this sequence revealed the presence of a regulatory site for a protein with zinc fingers. The presence of a response element to (-)-epicatechin in the human UCP2 promoter revealed that the inhibition of this gene in MDA-MB-231 breast cancer cells occurred at the transcriptional level. In this study, we propose the mechanism of action of (-)-epicatechin that could aid in cancer treatment. Full article

Prompt determination of the etiological agent is important in an outbreak of pathogens with pandemic potential, particularly for dangerous infectious diseases. Molecular genetic methods allow for arriving at an accurate diagnosis, employing timely preventive measures, and controlling the spread of the disease-causing agent. In this study, whole-genome sequencing of three SARS-CoV-2 strains was performed using the Sanger method, which provides high accuracy in determining nucleotide sequences and avoids errors associated with multiple DNA amplification. Complete nucleotide sequences of samples, KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021 were obtained, with sizes of 29.751 bp, 29.815 bp, and 29.840 bp, respectively. According to the COVID-19 Genome Annotator, 127 mutations were detected in the studied samples compared to the reference strain. The strain KAZ/Britain/2021 contained 3 deletions, 7 synonymous mutations, and 27 non-synonymous mutations, the second strain KAZ/B1.1/2021 contained 1 deletion, 5 synonymous mutations, and 31 non-synonymous mutations, and the third strain KAZ/Delta020/2021 contained 1 deletion, 5 synonymous mutations, and 37 non-synonymous mutations, respectively. The variations C241T, F106F, P314L, and D614G found in the 5′ UTR, ORF1ab, and S regions were common to all three studied samples, respectively. According to PROVEAN data, the loss-of-function mutations identified in strains KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021 include 5 mutations (P218L, T716I, W149L, R52I, and Y73C), 2 mutations (S813I and Q992H), and 8 mutations (P77L, L452R, I82T, P45L, V82A, F120L, F120L, and R203M), respectively. Phylogenetic analysis showed that the strains studied (KAZ/Britain/2021, KAZ/B1.1/2021, and KAZ/Delta020/2021) belong to different SARS-CoV-2 lineages, which are closely related to samples from Germany (OU141323.1 and OU365922.1), Mexico (OK432605.1), and again Germany (OV375251.1 and OU375174.1), respectively. The nucleotide sequences of the studied SARS-CoV-2 virus strains were registered in the Genbank database with the accession numbers: ON692539.1, OP684305, and OQ561548.1. Full article

CRISPR/Cas9, as a well-established gene editing technology, has been applied in numerous model organisms, but its application in wild-type E. coli remains limited. Pathogenic wild-type E. coli, a major cause of foodborne illnesses and intestinal inflammation in humans and animals, poses a significant global public health threat. The valine-glycine repeat protein G (VgrG) is a key virulence factor that enhances E. coli pathogenicity. In this study, PCR was used to identify 50 strains carrying the virulence gene VgrG2 out of 83 wild pathogenic E. coli strains, with only one strain sensitive to kanamycin and spectinomycin. A homologous repair template for VgrG2 was constructed using overlap PCR. A dual-plasmid CRISPR/Cas9 system, combining pTarget (spectinomycin resistance) and pCas (kanamycin resistance) with Red homologous recombination, was then used to induce genomic cleavage and knock out VgrG2. PCR and sequencing confirmed the deletion of a 1708 bp fragment of the VgrG2 gene in wild-type E. coli. IPEC-J2 cells were infected with E. coli-WT and E. coli ∆VgrG2, and treated with the mTOR inhibitor rapamycin to study the effects of VgrG2 on the mTOR signaling pathway. The qPCR results showed that VgrG2 activated the mTOR pathway, suppressed mTOR and p62 mRNA levels, and upregulated the autophagy-related genes and LC3-II protein expression. In conclusion, we utilized CRISPR/Cas9 technology to achieve large-fragment deletions in wild-type E. coli, revealing that VgrG2 activates the mTOR signaling pathway and upregulates autophagy markers. These findings offer new insights into E. coli genome editing and clarifies the pathogenic mechanisms through which VgrG2 induces cellular damage. Full article

As the most diverse genus of Salicaceae, Salix is primarily distributed in the temperate zone of the Northern Hemisphere, encompassing 350–500 species worldwide. The genus’s evolutionary history is complex due to significant genetic differentiation. Chloroplast genes, being highly conserved, serve as effective tools for studying uniparental inheritance and evolution. In this study, we sequenced and assembled the chloroplast genomes of five representative Salix species. Phylogenetic relationships were constructed using chloroplast genome data, and structural differences among lineages were compared. These Salix chloroplast genomes exhibited a typical quadripartite structure, with lengths ranging from 154,444 to 155,725 bp. We successfully annotated 131 genes, including 88 protein-coding genes, 35 tRNA genes, and 8 rRNA genes. Clade I showed higher variability in the SSC region, identifying five highly variable regions: petA-psbJ, rps16-rps3, ndhD, ccsA-ndhD, and ndhG-ndhI. Two rapidly evolving genes, ndhI and ycf4, were also identified. The total length of insertions and deletions (InDels) in Clade I was 1046 bp. Clade II exhibited greater variability in the LSC region, with four highly variable regions being identified: trnK-trnQ, ndhC-trnV, trnV, and psdE-petL. Four rapidly evolving genes—infA, rpoC1, rps18, and ycf1—were identified. The total length of InDels in Clade II was 1282 bp. Therefore, this study elucidated the chloroplast genome evolution across different Salix lineages, thereby providing deeper insights into intrageneric phylogenetic relationships. Full article

Acetic acid bacteria (AAB) are a group of bacteria, most of which can produce pigments. However, the mechanism of pigment production by AAB is unclear. A strain of AAB, Gluconacetobacter tumulisoli FBFS 97, which can produce a large amount of brown pigment (BP), was isolated in our previous research. In the current study, it was found that the BP yield of the FBFS 97 strain was enhanced in the presence of tyrosine, and an intermediate of melanin, L-3,4-dihydroxyphenylalanine (L-DOPA), was identified using ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The structural properties of BP were analyzed by pyrolysis gas chromatography–mass spectrometry (Py-GC-MS). All these analyses suggest that BP may be eumelanin, a type of melanin. Then, the eumelanin biosynthetic pathway was investigated in the FBFS 97 strain, and three related genes with eumelanin including pheA, yfiH, and phhB in its genome were found and knocked out, respectively. The results showed that eumelanin production increased 1.3-fold in the pheA deletion mutant compared to the wild-type FBFS 97 strain, but when either yfiH or phhB was knocked out, the eumelanin production in the mutants was the same as that in the wild-type FBFS 97 strain. Finally, a possible biosynthetic pathway for eumelanin in the FBFS 97 strain is proposed. Full article

Endothelin Receptor Type B (EDNRB) is expressed in a variety of cells during embryonic stage, including melanocyte precursors cells. Our previous studies found that 11 bp deletion of EDNRB caused the two-end black (TEB) coat color in Chinese pigs. In this study, we aimed to explore the mutant EDNRB on the formation of TEB coat color in Chinese pigs. We constructed recombinant plasmid for wild and mutant EDNRB and EDN1, respectively, and transfected the recombinant plasmid into mouse B16 melanoma cells in groups. Real-time fluorescent quantitative PCR (RT-qPCR) was performed to detect expression of genes that participate in melanin pathway, including PLCγ, Raf, MITF. Comparing to the wild-type EDNRB cells, expression of the three genes in the cell line expressing mutant EDNRB cells was significantly reduced. We measured the melanin content produced by transfected recombinant granulocytes of wild and mutant EDNRB and found that the amount of melanin in mutant EDNRB cells was significantly lower than that of the wild. Wound-healing assay confirmed that the migration and mobility rate of mutant EDNRB cells were significantly lower than the wild. Co-immunoprecipitation further confirmed that mutant EDNRB could not interact with the EDN1 protein. In conclusion, this study revealed that the 11 bp deletion of EDNRB reduced the melanin production, which may be caused by inhibiting the expression of PLCγ, Raf, and MITF. The mutant EDNRB reduced melanocyte migration and could not interact with the EDN1 protein. We explored the effect of mutant EDNRB in Chinese pigs with TEB coat color, and the results provided a reference for exploring molecular mechanism of mutant EDNRB on the formation of TEB coat color pigs. Full article

We generated and characterized knockout mutant lines of the OsPHS3 gene using the CRISPR/Cas9 system. The knockout lines of the OsPHS3 gene showed that 1 bp and 7 bp deletion, early termination codons were used for protein production. Agronomic characteristics of knock-out lines were reduced in plant height, culm diameter, panicle length, seed size and weight, except for the number of tillers. In addition, we analyzed the expression levels of carotenoid biosynthesis genes by qRT-PCR. Among the genes encoding carotenoid metabolic pathway enzymes, the level of transcripts of PSY1, PSY2, PSY3, PDS and ZDS were higher in the KO lines than in the WT line. In contrast, transcription of the ε-LCY, β-LCY and ZEP1 genes were downregulated in the KO lines compared to the WT line. Also, the KO lines decreased carotenoid content and ABA amount compared to WT, while preharvest sprouts increased. These results suggested that they would certainly help explain the molecular mechanisms of PHS in other crops, such as wheat and barley, which are susceptible to PHS. Full article

The 15q11.2q13 chromosomal region is particularly susceptible to chromosomal rearrangements due to low-copy repeats (LCRs) located inside this area. Specific breakpoints (BP1-BP5) that lead to deletions and duplications of variable size have been identified. Additionally, this specific region contains several imprinted genes, giving rise to complex syndromes (Prader–Willi, Angelman and 15q11-q13 duplication syndromes). 15q11.2-q13 duplication syndrome has been associated with neurodevelopmental disorders (hypotonia, developmental delay, speech delay and seizures) and ASD but is characterized by variable expressivity and reduced penetrance, features that make genetic counseling a complex procedure especially in prenatal cases. In the present study, a total of 14 pre- and postnatal cases were diagnosed as 15q11.2q13 duplication carriers using Affymetrix CytoScan 750 K array-CGH, and our analysis combined these with 120 cases existing in the literature. The inheritance pattern of the cases of this study is unknown, but as a review of the literature revealed, 62.96% of the affected carriers inherited the duplicated area from their mother. The combined results of this analysis (the present study and the literature) show that in the majority of the cases, the phenotype is a compound phenotype, with clinical characteristics that include ASD, intellectual disability, developmental delay and an absence of speech. The aim of this paper is to deliver new possibilities to genetic counseling that can be provided in prenatal and postnatal cases as the phenotype of 15q11.2q13 microduplication carriers cannot be fully predicted; so, clinical diagnoses should be a combination of molecular findings and clinical manifestations that are present. Full article

Soluble starch synthases (SSs) play important roles in the synthesis of cassava starch. However, the expression characteristics of the cassava SSs genes have not been elucidated. In this study, the MeSSIII-1 gene and its promoter, from SC8 cassava cultivars, were respectively isolated by PCR amplification. MeSSIII-1 protein was localized to the chloroplasts. qRT-PCR analysis revealed that the MeSSIII-1 gene was expressed in almost all tissues tested, and the expression in mature leaves was 18.9 times more than that in tuber roots. MeSSIII-1 expression was induced by methyljasmonate (MeJA), abscisic acid (ABA), and ethylene (ET) hormones in cassava. MeSSIII-1 expression patterns were further confirmed in proMeSSIII-1 transgenic cassava. The promoter deletion analysis showed that the −264 bp to −1 bp MeSSIII-1 promoter has basal activity. The range from −1228 bp to −987 bp and −488 bp to −264 bp significantly enhance promoter activity. The regions from −987 bp to −747 bp and −747 bp to −488 bp have repressive activity. These findings will provide an important reference for research on the potential function and transcriptional regulation mechanisms of the MeSSIII-1 gene and for further in-depth exploration of the regulatory network of its internal functional elements. Full article

The formation of fruit color in pepper is closely related to the processes of carotenoid metabolism. In this study, red wild-type pepper XHB, SP01, PC01 and their corresponding mutants H0809 (orange), SP02 (yellow), and PC02 (orange) were used as research materials. The Ggps, Psy, Lcyb, Crtz, Zep, and Ccs genes involved in carotenoid biosynthesis were cloned, and bioinformatics and expression analyses were carried out. The results showed that the full lengths of the six genes were 1110 bp, 2844 bp, 1497 bp, 2025 bp, 510 bp, and 1497 bp, and they encoded 369, 419, 498, 315, 169, and 498 amino acids, respectively. Except for the full-length Ccs gene, which could not be amplified in the yellow mutant SP02 and the orange mutant PC02, the complete full-length sequences of the other genes could be amplified in different materials, indicating that the formation of fruit color in the SP02 and PC02 mutants could be closely related to the deletion or mutation of the Ccs gene. The analytical results of real-time quantitative reverse transcription PCR (qRT-PCR) showed that the Ggps, Psy, Lcyb, Crtz, and Zep genes were expressed at different developmental stages of three pairs of mature-fruit-colored materials, but their patterns of expression were not consistent. The orange mutant H0809 could be amplified to the full Ccs gene sequence, but its expression was maintained at a lower level. It showed a significant difference in expression compared with the wild-type XHB, indicating that the formation of orange mutant H0809 fruit color could be closely related to the different regulatory pattern of Ccs expression. The results provide a theoretical basis for in-depth understanding of the molecular regulatory mechanism of the formation of color in pepper fruit. Full article

Neuroblastoma (NB) is the most frequent extracranial solid childhood tumor. Despite advances in the understanding and treatment of this disease, the prognosis in cases of high-risk NB is still poor. 17q gain has been shown to be the most frequent genomic alteration in NB. However, the significance of this remains unclear because of its high frequency and association with other genetic modifications, particularly segmental chromosomal aberrations, 1p and 11q deletions, and MYCN amplification, all of which are also associated with a poor clinical prognosis. This work reviewed the evidence on the clinical and biological significance of 17q gain. It strongly supports the significance of 17q gain in the development of NB and its importance as a clinically relevant marker. However, it is crucial to distinguish between whole and partial chromosome 17q gains. The most important breakpoints appear to be at 17q12 and 17q21. The former distinguishes between whole and partial chromosome 17q gain; the latter is a site of IGF2BP1 and NME1 genes that appear to be the main oncogenes responsible for the functional effects of 17q gain. Full article