Search Results (127)

Cabbage (Brassica oleracea var. capitata), a member of the Brassicaceae family, is an important vegetable crop grown worldwide. Self-incompatibility (SI) in cabbage is a key trait that prevents self-fertilization and inbreeding, thereby maintaining genetic diversity within populations. Although several genes related to SI have been reported, its genetic control remains unclear. In this study, we developed an F₂ population from the highly self-compatible (SC) cabbage line 87-534 and the highly self-incompatible (SI) line 01-20, both of which exhibit the S5 haplotype. The segregation analysis of the F₂ population revealed the possible control of SI by a major gene with additional modifying genetic factors. Bulk segregant analysis sequencing (BSA-Seq) and RNA sequencing (RNA-Seq) were performed on SI and SC samples selected from the F₂ population. BSA-Seq revealed a candidate region on chromosome 7 (C07: 7.45 Mb to 8.93 Mb), including 32 differentially expressed genes (DEGs). RNA-Seq identified a total of 2400 DEGs between the two pools, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses suggested that plant hormone biosynthesis and signaling, plant immune response were significantly enriched and may be involved in SI. The combined analysis of BSA-Seq and RNA-Seq identified six candidate genes associated with SI, and their expression was confirmed using quantitative real-time PCR (qRT-PCR). Among them, Bol023956 encodes fructokinase, Bol023986 is involved in plant defense response, Bol024018 is related to pollen development, Bol024012 encodes a transport protein for phytohormones, Bol023943 encodes chorismate mutase 3, and Bol012515 is an important regulatory gene for chloroplast synthesis. These six genes, potentially linked to SI, should be targets for further validation. These findings provide insights into the molecular mechanisms of SI in cabbage and the selection of superior cabbage varieties. Full article

Soil salinization is a source of major abiotic stress that severely limits the production of alfalfa (Medicago sativa L.), a globally critical forage legume for sustainable livestock production. Its complex autotetraploid genome and self-incompatibility greatly hinder salt tolerance genetic improvement, while the post-transcriptional regulatory mechanism of alfalfa salt stress response remains largely uncharacterized. This study aimed to narrow the gap between genome-wide genetic signals and causal regulatory mechanisms and identify core post-transcriptional regulators of alfalfa salt tolerance via a multi-layered integrative analysis pipeline. We performed a genome-wide association study (GWAS) using 220 globally collected alfalfa accessions, combined with public transcriptome integration, co-expression network analysis, 3′ untranslated region (3′UTR) motif discovery, and AlphaFold2-based protein-RNA docking simulation. We identified 20 significant salt tolerance-associated loci and prioritized the CCCH-type zinc-finger RNA-binding protein (RBP) MsCCCH20 as the core candidate regulator. We further screened 35 high-confidence target genes of MsCCCH20, detected conserved AU/AG-rich 3′UTR motifs, and provided structural predictions consistent with potential sequence-specific interactions (ipTM 0.70–0.79). Our findings establish a robust framework linking genetic association signals to post-transcriptional regulatory networks and provide high-confidence candidate genes and functional markers for the molecular breeding of salt-tolerant alfalfa. Full article

During the COVID-19 pandemic carbapenem-resistant Acinetobacter baumannii (CRAB) was found to be the major pathogen associated with ventilator-associated pneumonia in mechanically ventilated patients. This prompted us to analyze the post-pandemic mechanisms of carbapenem resistance, antibiotic resistance trends, and molecular epidemiology of CRAB in Croatia. In total, 94 CRAB isolates from two hospital centers, including outpatient settings, were investigated. Antimicrobial susceptibility testing was performed by broth microdilution. PCR was used to detect genes encoding carbapenemases of group A, B and D and extended-spectrum β-lactamases (ESBL). Randomly selected isolates were subjected to whole resistome analysis by Inter-array CarbaResist Kit and whole-genome sequencing (WGS). Phylogenetic tree and sequence types (STs) were retrieved from WGS. Plasmid incompatibility groups were determined by PCR-based replicon typing (PBRT). All isolates were extensively drug resistant (XDR), showing resistance to ceftazidime, cefepime, piperacillin–tazobactam, imipenem, meropenem, gentamicin, amikacin and ciprofloxacin, and 13% (n = 12) were also resistant to colistin. The Hodge and CIM test exhibited poor sensitivity with only 32 and 30% of isolates being identified as carbapenemase producers, respectively. PCR identified bla_OXA-23 as the dominant carbapenemase gene in both hospitals, found in 71% of the isolates (67/94). In an outpatient setting, bla_OXA-24/40 was dominant. bla_OXA-23 and bla_OXA-72 were the only allelic variants. The Inter-array CarbaResist Kit and whole-genome sequencing (WGS) identified a variety of aminoglycoside (armA, ant(3″)-IIa, aph(3″)-Ib, aph(6)-Id) and sulphonamide resistance (sul1 and sul2) genes. The representative bla_OXA-23-positive isolates belonged to ST2, while bla_OXA-72-positive isolates were allocated to ST492. These data show that there are different populations of XDR A. baumannii between hospital and outpatients. Full article

Carbapenemase-producing Enterobacterales (CPE) is a global threat. IMP-6, a prevalent carbapenemase in western Japan, is mostly disseminated via CTX-M-2 extended-spectrum β-lactamase (ESBL) co-producing Enterobacterales. However, the existence and characteristics of Enterobacterales harboring bla_IMP-6 without bla_CTX-M-2 remain unclear. We analyzed the phenotypic and genetic characteristics of clinical bla_IMP-6-harboring Enterobacterales isolates, focusing on those lacking bla_CTX-M-2. Overall, 220 bla_IMP-6-harboring isolates collected from 76 Japanese hospitals between 2014 and 2021 were characterized by antimicrobial susceptibility, presence of CTX-M-type ESBLs, plasmid incompatibility, plasmid transfer experiments, and genome sequencing and analysis. Among these, 203 co-harbored bla_CTX-M-2 group, with 90% of them demonstrating high conjugation frequency and broad-spectrum resistance to β-lactams. Of the remaining 17 isolates, nine lacked bla_CTX-M, while eight co-harbored bla_CTX-M-1 group (n = 2) or bla_CTX-M-9 group (n = 6). Eleven isolates carried nontransferable plasmids with genetic structures distinct from those of bla_IMP-6 and bla_CTX-M-2 co-encoding plasmids, including eight non-incompatibility N plasmids. Fifteen isolates carried only bla_IMP-6-encoding plasmids; two carried plasmids with bla_IMP-6 and bla_CTX-M (bla_CTX-M-27 or bla_CTX-M-65). This novel study revealed that bla_IMP-6 can exist without bla_CTX-M-2 on diverse, often nontransferable plasmids, suggesting distinct, lower dissemination pathways compared to those of epidemic bla_CTX-M-2 co-carrying plasmids and highlighting previously overlooked plasmids that necessitate close monitoring. Full article

Background: Gametophytic self-incompatibility (GSI) controlled by a multi-allelic S-locus, is inferred to have evolved before the spilt of the Rosidae and Asteridae. In Rosaceae, molecular characterisation of the genera Prunus and Malus reveals that different numbers of genes determine GSI specificity. In Prunus, one pistil-expressed (female) gene and one pollen (male) gene encode a series of stylar RNase (S-RNase) alleles and series of S-haplotype-specific F-box (SFB) alleles, respectively, thereby determining the female and male specificity. In contrast, in Malus, GSI specificity is controlled by one pistil gene and multiple pollen genes, known as SFB-brothers (SFBBs), which encode a series of S-RNase and SFBB alleles, respectively, within the S-locus, to determine female and male specificity. Despite these advances, the molecular mechanisms of these two genera remain largely unknown, and it is still uncertain how GSI originated or which factors shape the orientation, evolution, and function of the S-locus. Methods: Therefore, in this study, we applied a holistic integrative approach combining analyses of gene distribution, phylogenetic inference, biogeographic history, selective pressures, co-evolution, and protein interaction networks across three Prunus genomes (P. dulcis, P. persica, and P. avium) to elucidate the evolutionary forces driving sexual diversity and molecular specificity of GSI within the Rosaceae. Results: Our results indicated that rapid diversification of the Prunus S-locus was due to the repeated duplication events in the SFB, SLF, and S-RNase genes producing both functional and non-functional duplicates. Conclusions: In Rosaceae, diversity of S-locus mechanisms is shaped by lineage-specific selection, functional divergence, co-evolution of pistil- and pollen-expressed components, dynamic protein-interaction networks, geological history and climatic change. Full article

The cultivated chrysanthemum is the most important ornamental species in the genus Chrysanthemum. However, because it is predominantly hexaploid and additionally exhibits self-incompatibility, it harbors numerous functionally redundant genes and displays extremely high heterozygosity. As a result, its genomic architecture is highly complex, making it challenging to interpret data obtained from omics analyses such as RNA-seq. To provide a genetically tractable model, we previously developed Gojo-0, a self-compatible, pure line of the diploid wild species C. seticuspe. In this study, we established Gojo-1, an improved self-compatible pure line derived from Gojo-0 and its sibling lines, exhibiting enhanced viability and culture performance. Leveraging these traits, we performed CRISPR–Cas9 editing of the AGAMOUS orthologs and successfully isolated mutants with altered floral organ morphology, demonstrating the line’s suitability for functional genomics. Comparative genome analysis showed that, aside from chromosome 1, the Gojo-1 genome is highly similar to that of Gojo-0, whose complete sequence has been determined. Taken together, these features indicate that Gojo-1 will serve as a valuable resource for future omics-based studies and a broad range of additional research applications. Full article

Background: Listeria monocytogenes is an ubiquitous foodborne pathogen capable of persisting in food-processing environments, domestic settings, and water systems; consequently, the mere co-detection of the microorganism in a patient and in a food product is insufficient to support criminal causation. In judicial proceedings, attribution of invasive listeriosis to a specific food and food business operator requires a pathogen-specific evidentiary chain that exceeds the standards used for public health surveillance. Methods: We performed a retrospective medico-legal and methodological analysis of a fatal listeriosis case that triggered criminal prosecution for foodborne homicide, systematically assessing the investigative chain according to temporal plausibility, food traceability, compliance with European and ISO microbiological standards, interpretation of whole-genome sequencing (WGS) data for an ubiquitous pathogen, and clinical causation of death. Results: The analysis identified critical weaknesses in the accusatory reconstruction, including incompatibility with established incubation periods, lack of proof that the sampled food lot corresponded to the product actually consumed, deviations from standard microbiological procedures, reliance on a poorly documented “clinical” isolate for WGS, non-specific genomic findings within a widely disseminated clonal complex, and the presence of plausible alternative environmental reservoirs. Clinically, the immediate cause of death was more consistent with hypovolemic shock due to uncontrolled gastrointestinal bleeding than with ongoing listerial sepsis. Conclusions: This article demonstrates how, in cases involving ubiquitous pathogens, failure to adopt a pathogen-specific investigative and interpretative framework may lead to methodologically fragile criminal allegations, potentially increasing litigation burden and costs for the justice system. A methodologically robust approach integrating microbiology, genomics, epidemiology and medico-legal causation analysis is essential for fair and scientifically sound criminal proceedings. Full article

Dengue is the leading mosquito-borne viral cause of human illness and death. More than four billion people globally are at risk of dengue virus (DENV) infection, and most infections are asymptomatic or present with a non-specific febrile illness. We characterise the first complete DENV-2 genome from Sierra Leone, recovered from a febrile adult who tested RT-PCR–positive. The sequence was identified as DENV-2 genotype II, lineage F.1.1. Phylogenetically, the Sierra Leone genome formed a well-supported sister lineage with a 2024 USA DENV-2 genome; both were nested within but clearly diverged from Indian DENV-2 sequences (2021–2022) and were distinct from the Réunion DENV-2 clade. The degree of genetic divergence was incompatible with a recent or direct import of a South Asian lineage and was more consistent with diversification in an under-sampled Indian Ocean/South Asia network or outside this region in Africa. With a single Sierra Leone genome, the source and extent of local transmission remain unresolved. These findings underscore the benefits of integrating differential diagnostics and genomics into routine care for febrile illness and sustaining regional arboviral surveillance. Full article

Achieving completeness of multipartite bacterial genomes has been a difficult task, especially in rhizobia. In this study, we performed a deep bioinformatic analysis of the newly re-sequenced genome of Rhizobium favelukesii LPU83^T. This strain was isolated from acid soils in Argentina and is capable of nodulating several leguminous plants, although it is unable to fix nitrogen efficiently in any of them. Oxford Nanopore sequencing allowed us to completely assemble the symbiotic plasmid of the strain, pRfaLPU83b, and we discovered that it harbors three intact prophages and a high density of insertion sequences (ISs). These characteristics show why it is often so difficult to complete the symbiotic plasmids of rhizobial strains and the importance of having long-read sequencing methods. Upon detailed analysis of this replicon, we identified a complete conjugation system with gene structure consistent with quorum sensing-associated systems that may have contributed to the genetic mosaic structure of the strain. Furthermore, we identified in the symbiotic plasmid of R. favelukesii LPU83^T a large proportion of the symbiotic genes previously identified as essential for Biological Nitrogen Fixation (BNF) in symbiosis with alfalfa, with a high percentage of identity with respect to those of Sinorhizobium meliloti 2011. Among the determinants related to BNF, we found genes encoding the HrrP and SapA peptidases in the LPU83 genome, previously described and related to the degradation of nodule-specific cysteine-rich peptides. These peptides are essential for bacteroid differentiation and, therefore, efficient BNF. Our results show that despite having these genes, they are not directly responsible for the inefficient BNF phenotype of LPU83. Full article

Background: Plasmid-mediated horizontal transfer of antimicrobial resistance genes (ARGs) is a major driver of resistance dissemination across clinical and environmental settings. Urban rivers flowing through densely populated megacities represent critical interfaces where human-associated and environmental microbiomes intersect; however, the genetic structures and functional characteristics of resistance plasmids circulating in such environments remain insufficiently resolved. Methods: In this study, we conducted detailed genomic and phenotypic analyses of 11 ARG-bearing plasmids previously captured from the Tama River, an urban river flowing through the Tokyo megalopolis. These plasmids belonged to IncN, IncU, IncQ2γ, IncC, and IncPγ groups. Whole-plasmid sequencing, comparative genomic analyses, conjugation assays, and antimicrobial susceptibility testing were employed to characterize plasmid backbones, accessory resistance regions, mobile genetic elements, and conjugative transferability. Results: A total of 11 plasmids belonging to five major incompatibility groups (IncN, IncC, IncU+IncQ2γ, and IncP) were analyzed. These plasmids collectively encoded ARGs conferring resistance to five major antimicrobial classes, including aminoglycosides, β-lactams, tetracyclines, chloramphenicol, and mercury, and frequently harbored class 1 integrons, ISCR1 elements, and Tn3-derived inverted-repeat miniature elements (TIME). Notably, two plasmids (IncN and IncC) exhibited high structural similarity to clinically reported plasmids from geographically distant regions, whereas multiple IncP plasmids and one multi-replicon IncU+IncQ2γ plasmid displayed accessory-region architectures characteristic of environmental plasmids and broad host-range transferability. Antibiotic susceptibility testing demonstrated that these plasmids substantially increased resistance levels in hosts. Conclusions: This study reveals that urban river environments can harbor both clinically related and environmentally unique multidrug resistance plasmids, shaped by diverse mobile genetic elements. By providing nucleotide-level structural and functional evidence, this study highlights urban rivers as potential ecological hubs linking clinical and environmental resistance plasmid pools and supports the importance of continued monitoring of resistance plasmids in megacity-associated river systems. Full article

In populations with limited genotyping, single-step genomic best linear unbiased predictions (ssGBLUP) can produce biased or less accurate genomic predictions due to incompatibilities between genomic and pedigree relationship matrices. The study evaluated the impact of five alternative ssGBLUP models for genomic predictions of milk, fat, and protein yield production traits in South African Holstein cattle. The dataset included 696,413 milk production records and pedigrees of 541,325 animals. Production traits were 305-day lactation yields for milk, protein, and fat. Genotype data were based on the Illumina 50K chip v3, with 53,218 SNPs. A total of 1221 animals with genotypes and 41,407 SNP markers were in the final dataset. The five models used to estimate genomic estimated breeding values (GEBVs) were the single-step method (ssGBLUP), ssGBLUP accounting for inbreeding (ssGBLUP_Fx), ssGBLUP with unknown parent groups (ssGBLUP_upg), and two ssGBLUP models with blending, tuning, and scaling parameters set to optimum values in constructing the inverse of the unified relationship matrix (ssGBLUP_adjusted). Realized prediction accuracies were highest for ssGBLUP_adjusted models (6–7% improvements compared to ssGBLUP). Accuracy of GEBVs for milk, protein, and fat yields ranged from 0.23, 0.29, and 0.30 for both ssGBLUP and ssGBLUP_Fx, 0.26, 0.32, and 0.34 for ssGBLUP_upg, and 0.29, 0.35, and 0.37 for ssGBLUP_adjusted models, respectively. Corresponding bias, expressed as regression coefficients, ranged from 0.30, 0.31, and 0.36 for ssGBLUP; 0.31, 0.32, and 0.37 for ssGBLUP_Fx; 0.41, 0.44, and 0.49 for ssGBLUP_upg; and 0.44, 0.47, and 0.53 for ssGBLUP_adjusted models, respectively. The improved accuracy and reduced bias observed with the ssGBLUP_adjusted underscores the importance of optimizing the blending of pedigree- and genome-based relationships to achieve more reliable GEBVs, thereby improving selection decisions in Holstein dairy cattle. Full article

Background: Carbapenem-resistant Escherichia coli (CREC) producing OXA-48-like carbapenemase was first detected in Hungary in 2022. The aim of the present study was to characterize such strains isolated in 2022–2025 in Baranya County, Hungary. Methods: Antibiotic susceptibility and the whole-genome sequence (WGS) of E. coli isolates, identified as OXA-48-like carbapenemase producers using the CARBA-5 NG test, were established. The transferability of bla_OXA-48-like plasmids was tested by conjugation. Results: Of the 6722 non-repeat E. coli isolates, 6 produced an OXA-48-like carbapenemase. They exhibited variable resistance to ertapenem and were susceptible to imipenem and meropenem. WGS revealed that all OXA-48-like producer E. coli belonged to high-risk clones: two clonally related OXA-181-producer E. coli ST405 were isolated in Hospital A, three OXA-244-producing E. coli ST38 (two identical via cgMLST from Hospital B), and an OXA-48-producing E. coli ST69. The bla_OXA-48 and bla_OXA-244 genes were chromosomally located, while bla_OXA-181 was on a non-conjugative IncFIB-IncFIC plasmid. So far, the bla_OXA-181-bearing plasmid of this incompatibility type has only been described in Ghana, but all bla_OXA-48-like gene-carrying transposons in this study have already been identified in Europe and other continents. The E. coli ST38 isolates, showing close association based on core genome SNP distances to European and Qatari strains, belonged to Cluster A and harbored bla_CTX-M-27. All but the E. coli ST69 isolate had cephalosporinase gene(s). Conclusions: This study describes small-scale intra-hospital transfers of OXA-48-like carbapenemase-producer E. coli. Interestingly, E. coli ST405 of Hungary carried bla_OXA-181 on an IncFIB-IncFIC plasmid, which has only been reported from Africa so far. Full article

Serine protease inhibitor A3 (SERPINA3), also called α-1-antichymotrypsin, is a serine protease involved in placental dysfunction. This study examines SERPINA3 polymorphisms and haplotypes for associations with maternal hypertensive disorders of pregnancy (HDPs) and preeclampsia with severe features (sPE) or Hemolysis, Elevated Liver Enzymes, and Low Platelet (HELLP) syndrome in mother–baby dyads (HDP) and mother–father–baby triads (sPE/HELLP). This retrospective case–control study examined two patient cohorts, HDPs and severe PE/HELLP syndrome. The HDP population included cases (n = 142) and controls (n = 168) of mother–baby dyads recruited from a large, urban, safety-net hospital in Los Angeles. The sPE/HELLP syndrome population included cases (n = 189) and controls (n = 28) of mother–father–baby triads recruited through HELLP syndrome research websites. Cases were verified by medical chart abstraction when possible. Two SERPINA3 SNPs, rs4934 and rs1884082, were genotyped from saliva samples, mouthwash, or buccal swabs. The Haplin package in R was used to perform genetic association analyses. No evidence of increased risk related to individual SERPINA3 SNPs or haplotypes for the developing HDPs or sPE/HELLP was found in individual nor combined cohorts. In the HDP cohort, the g-a haplotype (relative to T-G haplotype) was borderline significant for increased risk of HDPs when carried by the child (double dose: RR = 1.58, 95% CI: (1.00, 2.52), p = 0.05). We observed significant parent-of-origin (PoO) effects in the combined cohort: specifically, an increased risk of HDPs/sPE/HELLP if the mother carries a double copy for both rs4934 (RR = 3.03, 95% CI (1.50, 6.09), p < 0.01) and rs1884082 (RR = 2.38, 95% CI (1.22, 4.71), p = 0.01). A reduced risk of HDPs/sPE/HELLP was observed for rs4934 (RR = 0.54, 95% CI (0.31, 0.98), p = 0.04) and rs1884082 (RR = 0.52, 95% CI (0.30, 0.91), p = 0.02) with child carriage of the maternally inherited allele. In contrast, child carriage of a paternally inherited copy of the variant allele for rs4934 increased risk of HDPs/sPE/HELLP (RR = 1.54, 95% CI (1.09, 2.20), p = 0.02). There was no evidence that SERPINA3 gene polymorphisms and haplotypes were associated with risk of HDPs or sPE/HELLP. However, significant PoO effects were observed in the combined cohort analysis, with child carriage of rs4934 that is maternally inherited decreasing HDPs/sPE/HELLP risk while a paternally inherited copy increases risk, suggesting a role for maternal–fetal genomic incompatibility. Full article

Potato (Solanum tuberosum L.) is a globally important food crop, but its tetrasomic inheritance and diploid self-incompatibility have limited the discovery of potato genes and progress in breeding. Here, we developed an F₂ segregating population consisting of 174 lines by crossing a self-compatible genome-homozygous diploid line (Y8, female parent) with a heterozygous diploid line (IVP101, male parent), followed by selfing. Using whole-genome resequencing, we constructed a high-density genetic map containing 4464 recombinant bin markers with an average physical distance of 165.51 Kb. Phenotypic evaluation of 8 traits related to yield, tuber shape, and tuber eye number across three environments revealed significant parental differences and wide phenotypic variation within the F₂ population. QTL (Quantitative trait loci) mapping using this genetic map and multi-environment phenotypic data identified 89 QTLs, including 7 previously reported QTLs/genes. In addition, 10 QTLs were stably detected across multiple seasons (stable QTLs). Further genetic effect analysis showed that favorable alleles of these stable QTLs significantly enhanced phenotypic values. Notably, two pleiotropic QTLs were identified on chromosomes 5 and 12; the major-effect QTL on chromosome 12 (qTY-12-6, qTS-12-3, and qTE-12-4) exhibited high phenotypic variance explained (PVE). Its favorable allele from Y8 significantly increased mean tuber weight, tuber number per plant, and promoted rounder tuber shape while reducing eye number, simultaneously improving yield and quality. Collectively, this study provides a reference for genetic mapping using homozygous and heterozygous diploid parents, and the identified QTLs offer valuable genetic resources for potato breeding and molecular mechanism research, enhancing our understanding of the genetic regulation of yield, tuber shape, and eye number in potato. Full article

Grafting is the process of joining parts of two plants, allowing the exchange of molecules such as small RNAs (including microRNAs and small interfering RNAs), messenger RNAs, and proteins between the rootstock and the scion. Genome editing by grafting exploits RNAs, such as tRNA-like sequences (TLS motifs), to deliver the components (RNA) of the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) system from transgenic rootstock to wild-type scion. The complex Cas9 protein and sgRNA-TLS produced in the scion perform the desired modification without the integration of foreign DNA in the plant genome, resulting in heritable transgene-free genome editing. In this review, we examine the current state of the art of this innovation and how it helps address regulatory problems, improves crop recovery and selection, exceeds the usage of viral vectors, and may reduce potential off-target effects. We also discuss the promise of genome editing by grafting for plants recalcitrant to in vitro culture and for agamic-propagated species that must maintain heterozygosity for plant productivity, fruit quality, and adaptation. Furthermore, we explore the limitations of this technique, including variable efficiency, graft incompatibility among genotypes, and challenges in large-scale application, while highlighting its considerable potential for further improvement and future broader applications for crop breeding. Full article