Resistance Region Research Articles

Clonal Spread and Genetic Mechanisms Underpinning Ciprofloxacin Resistance in Salmonella enteritidis

Salmonella enteritidis is a major cause of foodborne illness worldwide, and the emergence of ciprofloxacin-resistant strains poses a significant threat to food safety and public health. This study aimed to investigate the prevalence, spread, and mechanisms of ciprofloxacin resistance in S. enteritidis isolates from food and patient samples in Shanghai, China. A total of 1625 S. enteritidis isolates were screened, and 34 (2.1%) exhibited resistance to ciprofloxacin. Pulsed-field gel electrophoresis (PFGE) results suggested that clonal spread might have persisted among these 34 isolates in the local area for several years. Multiple plasmid-mediated quinolone resistance (PMQR) genes, GyrA mutations in the quinolone resistance-determining region (QRDR), and overexpression of RND efflux pumps were identified as potential contributors to ciprofloxacin resistance. PMQR genes oqxAB, qnrA, qnrB, and aac(6’)-Ib-cr as well as GyrA mutations S83Y, S83R, D87Y, D87G, D87N, and S83Y-D87Y were identified. The co-transfer of the PMQR gene oqxAB with the ESBL gene blaCTX-M-14/55 on an IncHI2 plasmid with a size of ~245 kbp was observed through conjugation, highlighting the role of horizontal gene transfer in the dissemination of antibiotic resistance. Sequencing of the oqxAB-bearing plasmid p12519A revealed a 248,746 bp sequence with a typical IncHI2 backbone. A 53,104 bp multidrug resistance region (MRR) was identified, containing two key antibiotic resistance determinants: IS26-oqxR-oqxAB-IS26 and IS26-ΔISEcp1-blaCTX-M-14-IS903B. The findings of this study indicate that ciprofloxacin-resistant S. Enteritidis poses a significant threat to food safety and public health. The persistence of clonal spread and the horizontal transfer of resistance genes highlight the need for enhanced surveillance and control measures to prevent the further spread of antibiotic resistance.

Occurrence and Impact of Papaya Ring Spot Virus in the Marathwada Region of Maharashtra, India

Papaya ring spot virus (PRSV) is a major challenge to global papaya cultivation, including in the Marathwada region of Maharashtra, India. This study aimed to survey the prevalence of PRSV disease across three agroclimatic zones of Marathwada during, 2022. Infected plants exhibited various symptoms on leaves such as vein clearing, chlorosis, mosaic, blistering, leaf curling, puckering and shoestring appearance. Other symptoms such as, ringspots on leaves, fruits and stems, oily streaks on petioles and stems, malformed fruits, stunted growth of plants. Depending on the stage of infection, diseased plants produced few or no fruits. The survey revealed that, an average PRSV incidence ranging from 0.03% to 100%. Further analysis examined the influence of PRSV incidence on papaya cultivar, crop age and agroclimatic zones. Results indicated that older plants were more susceptible to PRSV than younger ones. Among the cultivars studied, the Red Lady cultivar demonstrated high susceptibility to the virus. However, there were no significant differences in the percent disease index (PDI) across the agroclimatic zones. These findings highlight the need for targeted management strategies, including the development of resistant cultivars and region wise disease control measures, to reduce the impact of PRSV on papaya production.

The predominant role of FliC contributes to the flagella-related pathogenicity of ST34 S. Typhimurium monophasic variant

Over the past two decades, the monophasic variant of Salmonella enterica serovar Typhimurium (S. Typhimurium) has rapidly emerged and increased worldwide. This upsurge is especially true for the European clone of the ST34 S. Typhimurium monophasic variant. The key distinction between ST34 S. Typhimurium and its monophasic variant is that the genes that encode for second-phase flagellin (FljB) and the regions around it have been replaced with various multidrug resistance cassettes. To determine if the loss of fljB or the retention of fliC,-the gene coding for first-phase flagellin (FliC)-, would impact its pathogenicity, we constructed various mutations, including deletions of fljB, fliC, fliC/fljB, and strains where fliC was replaced with fljB. Our results showed that the loss of fljB in ST34 S. Typhimurium and its monophasic variant does not affect bacterial motility, cell infection ability, survival in macrophages, induced pro-inflammatory cytokines secretion, virulence, or persistent infection in mice. However, the deletion of fliC caused a significant decrease in these outcomes for both strains, while the replacement of fliC with fljB only partially restored these capabilities. Consequently, we determined that FliC is predominant in the flagellar expression of ST34 S. Typhimurium other than FljB. This finding demonstrates that replacing the fljB gene with various resistance regions in ST34 S. Typhimurium monophasic variants can enhance bacterial survival under specific antibiotic farming practices and spread globally.

Two multidrug-resistant Proteus mirabilis clones carrying extended spectrum beta-lactamases revealed in a single hospital department by whole genome sequencing

Proteus mirabilis bacteria is a component of normal intestinal microflora of humans and animals, but can also be found in hospital settings causing urinary tract infections and sepsis. The problem of treating such infections is complicated by multidrug-resistant isolates producing extended spectrum beta-lactamases (ESBL), and the number of ESBL-carrying P. mirabilis strains has significantly increased recently.This study presents a detailed analysis of 12 multidrug-resistant P. mirabilis isolates obtained from the wounds of different patients in one surgical department of a multidisciplinary hospital in Moscow, Russia, using the short- and long-read whole genome sequencing. The isolates under investigation divided into two clusters (clones) C1 and C2 based on their genomic profiles and carried antimicrobial resistance (AMR) genes corresponding well with phenotypic profiles, which was the first case of reporting two different P. mirabilis clones obtained simultaneously from the same specimens at one hospital, to the best of our knowledge. Some genes, including ESBL encoding ones, were specific for either C1 or C2 (aac(6′)-Ib10, ant(2″)-Ia, qnrA1, blaVEB-6 and fosA3, blaCTX -M-65, correspondingly). Additionally, the Salmonella genomic islands 1 were found that differed in composition of multiple antibiotic resistance regions between C1 and C2 groups. CRISPR-Cas system type I-E was revealed only in C2 isolates, while the same set of virulence factors was determined for both P. mirabilis clones.Diversity of all genetic factors found in case of simultaneous existence of two clones collected from the same source at one department indicates high pathogenic potential of P. mirabilis and poses a requirement of proper spreading monitoring. The data obtained will facilitate the understanding of AMR transfer and dynamics within clinical P. mirabilis isolates and contribute to epidemiological surveillance of this pathogen.

3R-CuCrO2 delafosite: crystal growth, crystal structure, dielectric and DC conductivity properties

Single-crystal samples of the 3R-CuCrO2 phase (R3m, a = 2.9613(2) Å, c = 17.098(2) Å) with a delafossite structure were grown by the flux method. Structural parameters were refined by X-ray structural analysis. The elemental composition of the grown crystals was confirmed by Auger electron spectroscopy. A threshold electric field switching effect from a high-resistance to a low-resistance state was discovered. The effect is characterized by a jump in electrical resistance (up to 5 orders of magnitude at E = 4.7 kV/cm, T = 120 K) and S-shaped current–voltage characteristics with a region of negative differential resistance. The temperature dependences of dielectric permittivity and dielectric loss tangent exhibit a Debye-type relaxation process with an activation energy of 0.51(3) eV. The observed features of dc conductivity, current–voltage characteristics, and dielectric properties interpreted on the basis of the existence of charge carriers in a small polaron state and the destruction of this state by the electric field.

Density Modulated Vertical Carbon Nanotube Architectures with Bolometric Effect

Novel density‐modulated carbon nanotube (CNT) blocks with controlled and tunable CNT densities in adjacent layers have been developed. Regions with varying densities are laterally patterned into different shapes with submicron resolution, enhancing the fabrication flexibility of new 3D nanoelectromechanical systems for diverse sensing applications. This technology platform adjusts lateral electrical resistance, mechanical properties such as effective Young's modulus, and both lateral and vertical thermal conductivity, which can vary by several orders of magnitude. Highlighting its potential, the CNTs exhibit broadband blackbody absorption from ultraviolet (UV) to terahertz (THz). The initial bolometric detector demonstrates features such as a voltage responsivity = 20.5 V W−1, a response time of less than 0.1 ms, measured robust operation up to 200 °C, with fabricated device dimensions of 20 × 30 μm2, and a low‐cost design suitable for mass production. Further optimizations of the lateral design can reduce the device dimensions to as small as 5 × 5 μm2 and improve the absorption in the main resistance region. Thus, this architecture provides a platform technology to increase the responsivity of the fabricated new 3D‐based bolometer devices by several orders of magnitude. Tiny objects such as biological cells can be characterized in real time.

Biomechanical evaluation of stability after mandibular sagittal split osteotomy for advancement by Obwegeser–Dal Pont and Puricelli techniques using three-dimensional finite elements

BackgroundThe surgical treatment for mandibular repositioning using a bilateral sagittal split osteotomy (BSSO) favours the development of techniques that result in adequate repair and stability. In Puricelli’s mandibular sagittal split osteotomy (PMSSO) proposal, the vertical lateral cut osteotomy is located in the interradicular space between the lower first molar and second premolar.ObjectivesThis in silico study aimed to investigate the mechanical stability of PMSSO and compare it with the classical Obwegeser–Dal Pont technique for mandibular advancement.Materials and methodsA computational geometric model of the mandible was created in a virtual environment using computer-aided design (CAD) software. After reproducing the advancements, two test groups were developed: GTOD10, Obwegeser–Dal Pont osteotomy, and GTP10, Puricelli osteotomy, both simulating a 10-mm mandibular advancement, allowing for measuring the area of overlap between bone segments. With the geometric changes promoted by the osteotomy, boundary conditions of displacement and force were applied to a CAD software based on finite element analysis (FEA), allowing for quantitative and comparative analysis of the stress and vertical displacement of the mandible, mechanical measurements that may be associated with strength and stiffness.ResultsA 17.48% higher stress was observed in the GTP10 group than in GTOD10. However, the region of highest stress in GTP10 was found in a part of the bone that was still intact and far from the area of fragility caused by lateral vertical osteotomy. In contrast, in GTOD10, the region with high stress was in a less resistant bone region. The GTP10 group showed a 28.73% lower displacement than GTOD10. The area of overlap between the proximal and distal segments of the mandible was 33.13% larger in the GTP10 than in the GTOD10 group.ConclusionThe PMSSO method, performed in large mandibular advancements, keeps the point of highest stress away from the mandibular fragility zone. Considering the same amount of advancement, it also promotes less displacement and larger areas of bone overlap.Clinical relevanceThe results suggest that PMSSO, applied in large mandibular advancement, presents greater postoperative stability.

Application of Electromagnetic Method in the Detection of Buried Karst Groundwater in the North-South Archaic Uplift, Ningxia, China

Abstract The North-South Archaic Uplift Karst Area, situated in the Ningxia Hui Autonomous Region, exemplifies the presence of underground karst formations in northern China. This work utilizes the regional hydrogeological survey to carry out geophysical investigations. The objective is to examine the resistivity qualities of layers and formations in order to investigate the attributes of subterranean karst water. The results indicate the existence of karst groundwater within the carbonate fault zone, covered by Quaternary loess with a high resistance and Neogene mudstone with a low resistance. The resistivity of the fault zone is relatively lower compared to the surrounding carbonate rock. The core principle of this rule can be concisely stated as “detect regions of high resistance within regions of low resistance, and detect regions of low resistance within regions of high resistance.” The electrical characteristics of the subterranean karst formation greatly aid in identifying ideal locations for investigating karst groundwater.

Molecular characterization of the tet (M)-carrying transposon Tn7124 and plasmids in Escherichia coli isolates recovered from swine.

Here, we report the genetic features and evolutionary mechanisms of two tet (M)-bearing plasmids (pTA2 and pTA7) recovered from swine Escherichia coli isolates. The genetic profiles of pTA2 and pTA7 and corresponding transconjugants were accessed by S1 nuclease pulsed-field gel electrophoresis and Southern hybridization, followed by whole genome sequencing and bioinformatics analysis. The biological influences of pTA2 and pTA7 were determined by stability and direct competition assays. Both pTA7 and pTA2 had the IncR backbone sequences but differed in the multidrug resistance region (MDR). The MDR of pTA2 consisted of sul3, tet (M), qnrS1, bleO, oqxAB, floR, aadA1, cmlA1, aadA2, and tet (A)-tetR (A) in addition to 22 insertion sequences. Notably, pTA2 carried the novel complex Tn7124 (IS26-ctp-lp-tet (M)-hp-IS406tnp-IntI4-IS26) harboring tet (M). The fragment carrying tet (M) (IS26-ctp-lp-tet (M)-IS406 tnp-ctp-aadA1-cmlA1-aadA2-dfrA12-IntI1), named Tn6942-like, and the two resistance modules ISVsa3-VirD2-floR-lysR and tet (A)-tetR (A) were located in the MDR of pTA7. Both pTA2 and pTA7 were highly stable in E. coli DH5α cells with no fitness cost to the host or disadvantage in growth competition. These results indicate that transposons carrying tet (M) continuously integrate via mediation with an insertion sequence, which accelerates the transmission of tet (M) in E. coli isolates through integration of other drug-resistant genes, thereby posing a potential serious threat to the efficacy of clinical treatment.

Precise determination of electric field applied to charged materials in liquid via van der Pauw technique

The electric field is a fundamental physical quantity that determines the characteristics or behavior of charged materials in liquids. The precise characterization of charged materials involving nanoparticles or biomaterials such as cells and extracellular vesicles (EVs) requires a rigorous calculation of the electric field applied to these materials. However, unlike solid-state materials, the precise measurement of the electric field applied in liquids is challenging because of liquid-electrode interface resistance and non-uniform electric-field regions near electrodes. This study proposes a method for determining the precise electric field in liquids using the van der Pauw measurement technique. The conductivity of the liquid was measured using a microfluidic channel with a van der Pauw configuration. The electric field in the liquid was then calculated based on the relationship between the conductivity and current density. The accuracy of the proposed method was verified by measuring the conductivity of standard solutions and phosphate-buffered saline (PBS), followed by determining the electric field applied to the nanoparticles in these solutions. In addition, the proposed method was used to determine the zeta potential of charged nanoparticles. This simple method for determining liquid conductivity and calculating electric fields in liquids could be effectively used for various electrochemical studies.

Numerical Simulation of Secondary Hydrate Formation Characteristics and Effectiveness of Prevention Methods

The exploitation of natural gas hydrates by the pressure reduction method is affected by the decomposition heat absorption effect, and the range of the formation temperature reduction area is expanding. At the same time, the temperature reduction phenomenon is more significant around the production wells under the influence of gas throttling and expansion effects, and hydrate formation will occur under certain temperature and pressure conditions, leading to blockage of effective seepage channels in the reservoir in the region and elevation of seepage resistance, which may affect the output of hydrate decomposition gas. A numerical simulation model is constructed for the purpose of studying the secondary hydrate generation pattern around the well, analyzing the impact of secondary hydrates around wells on the production capacity, and assessing the effectiveness of prevention methods to inform the actual production of hydrates. The results demonstrate that secondary hydrate is typically formed in the near-well area of the upper part of the production well, and the secondary hydrate around the upper part of the production well is the first to be formed, exhibiting the highest saturation peak and the latest decomposition. The formation of the secondary hydrate can be predicted based on the observed change in temperature and pressure, and the rate of secondary hydrate formation is markedly rapid, whereas the decomposition rate, approximately 0.285 mole/d, is relatively slow. Additionally, the impact of secondary hydrates on cumulative gas production is insignificant, and the effect of secondary hydrates on capacity can be ignored. Hot water injection, wellbore heating, and reservoir reconstruction can effectively eliminate secondary hydrates around the well. Reservoir reconstruction represents a superior approach to the elimination of secondary hydrates, which can effectively enhance production capacity while preventing the generation of secondary hydrates.

Quantitative Trait Loci (QTL) Mapping for Disease Resistance in Crop Species Using Advanced Biostatistical Approaches

Quantitative Trait Loci (QTL) However, continued mapping of the genetic region(s) in disease resistance in crop species is indispensable for the development of high-yielding, robust crop species. Phenotypic trait-based QTL mapping is a bridge between a specific genomic region and a genetic marker of resistance to disease on the population level or to a translated genetic marker of disease resistance. Using advanced biostatistical methods, such as mixed models and Bayesian inference, this study increases the accuracy and resolution of QTL identification (e.g., wheat, rice, and maize). It is found that a more robust analysis can furnish additional robustness that considers the interaction of environment and genetic variance and population structure, both significant yet frequently neglected facets in standard QTL mapping. By combining crop breeders with genomics-based cutting-edge biostatistical tools, we can choose plants resistant to disease.

Identification and Validation of Blast Resistance Loci from the Durable Resistance Cultivar Hahng Yi 71

One of the effective strategies for developing blast disease-resistant cultivars to mitigate the yield losses caused by Pyricularia oryzae is the discovery of new genetic resources containing resistance genes. In the present study, a Thai landrace glutinous rice cultivar Hahng Yi 71 (HY71) was used as a durable, broad resistance source to identify QTLs against blast fungus and crossed with a susceptible recurrent parent cultivar RD6, generating 56 BC4F5 lines. The BC4F5 population was tested with six blast isolates, including THL54, THL583, THL658, THL690, THL795, and THL1119, and evaluated with 161 SSR markers to identify resistance regions using modified bulk segregation analysis. Single marker analysis showed 7 markers linked to a resistance reaction located on chromosomes 2, 4, and 5, then tentatively designated as qBL2-RD6, qBL4-HY71, and qBL5-HY71, respectively. Two introgressed lines from the mapping population, KKN97057-7-1-1-2-5-NKI-4-1 and KKN97057-7-1-1-2-5-NKI-5-1, were the qBL5-HY71 donor for introgressing into two rice lines, RGD07123-MS12-MS22-MS1, and RGD07123-MS12-MS22-MS9, which generated two single crosses and a backcross population by marker-assisted selection (MAS) using the linked markers RM39 and RM164. Three improved lines, RGD10021-MS18-B-MS8-MS40, RGD10031-MS-MS3-B-MS9-MS42 (single cross), and RGD11086-MS-MS15-MS10-MS19 (backcross), carrying qBL5-HY71, were tested for their resistance against leaf and neck blast disease by 62 and 8 blast isolates, respectively. The disease screening results showed that qBL5-HY71 was very effective in controlling leaf and neck blast. This study demonstrates the effectiveness of resistance loci qBL5-HY71 from HY71 on chromosome 5 and their linked markers in improving durable blast resistance in rice breeding programs.

Multidrug-resistant tuberculosis clusters and transmission in Taiwan: a population-based cohort study.

Multidrug-resistant tuberculosis (MDR-TB) remains a challenge in the TB program of Taiwan, where 0.5% of new cases and 2.1% of previously treated cases were resistant to at least rifampin (RIF) and isoniazid (INH). Since >80% of our MDR-TB are new cases, genotyping of MDR Mycobacterium tuberculosis is implemented to facilitate contact investigation, cluster identification, and outbreak delineation. This is a population-based retrospective cohort study analyzing MDR-TB cases from 2019 to 2022. Whole genome sequencing (WGS) was performed using the Illumina MiSeq and analyzed using the TB Profiler. A single nucleotide polymorphism (SNP) threshold of ≤ 12 and phylogenetic methods were used to identify putative transmission clusters. An outbreak was confirmed using genomic data and epidemiologic links. Of the 297 MDR-TB cases, 246 (82.8%), 45 (15.2%), and 6 (2.0%) were simple MDR, extensively drug-resistant tuberculosis (pre-XDR-TB) and extensively drug-resistant tuberculosis (XDR-TB), respectively. The sublineage 2.2 modern Beijing was the predominant (48.8%) MDR-TB strain in Taiwan. Phylogenetic analysis identified 25.3% isolates in 20 clusters, with cluster sizes ranging from 2 to 13 isolates. Nevertheless, only 2 clusters, one household and one community, were confirmed as outbreaks. In this study, we found that males had a higher risk of MDR-TB transmission compared to females, and those infected with the sublineage 2.1-proto-Beijing genotype isolates were at a higher risk of transmission. Furthermore, 161 (54.2%) isolates harbored compensatory mutations in the rpoC and non-rifampicin resistant determinant region (non-RRDR) of the rpoB gene. MDR-TB strains containing rpoB S450L and other compensatory mutations concurrently were significantly associated with clusters, especially the proto-Beijing genotype strains with the compensatory mutation rpoC E750D or the modern Beijing genotype strains with rpoC D485Y/rpoC E1140D. Routine and continuous surveillance using WGS-based analysis is recommended to warn of risks and delineate transmission clusters of MDR-TB. We proposed the use of compensatory mutations as epidemiological markers of M. tuberculosis to interrupt putative MDR-TB transmission.

Engineering the mass transport properties in potassium-ion intercalated pristine Prussian blue for sustainable potassium-ion batteries

Potassium-ion batteries (PIBs) could be a cheaper and more abundant alternative to lithium-ion batteries, offering faster charging and suitability for large-scale energy storage. Prussian blue (PB) is prepared through a simple wet chemical method, and its intercalation affinity for K+ ions is tested using linear sweep voltammetry (LSV). The diffusion resistance (Rw: ∼116 Ω Hz1/2) and low-frequency region slope (m: ∼0.63) are found high for the third LSV drive (Seg-3), indicating passivation of the PB surface which leads to a double-layer formation. Most of the K+ ions are intercalated into PB until three LSV segments. After that PB surface is passivated and prohibits further LSV-driven K+ ions intercalation. On average, the Seg-3 sample exhibits a 58 % higher lattice strain in comparison to the as-prepared PB. A capacity of 27 mAh g−1 @ 2 mA g−1 in aqueous media is recorded for the Seg-3 sample and a capacity drop of 4 mAh g−1 and Coulombic efficiency of 99.3 % is recorded under 100 cycles. These findings are further comprehensively validated through multi-technique approaches. The observed affinity and single-stage LSV-driven intercalation of K+ ions highlight the perspective of PB as an electrode material for aqueous potassium ion batteries (a-PIBs).

Three-dimensional interpretation of magnetotelluric data at Fogo Volcano, Azores Islands

The resistivity structure of Fogo volcano and the seismically active Congro region of São Miguel Island has been determined by 3-D inversion from 44 magnetotelluric soundings to yield new insights into the internal architecture of this volcanic island. Following comprehensive testing of processing codes to yield optimum magnetotelluric responses from the collected time-series, a robust electrical resistivity model was obtained. Sensitivity analysis of various features from the inversion process was used to determine their reliability, and aid geological interpretation. The magnetotelluric data imaged, and provided new structural insights into the Ribeira Grande geothermal system on the northern flank of Fogo volcano, where a shallow low resistivity (1 - 5Ωm) region has strong correlation with borehole data, and is shown to be an excellent proxy for mapping temperature and clay alteration mineralogy. Beneath the central edifice of Fogo volcano and also throughout the Congro region, the geology is very resistive, however the new magnetotelluric observations do not yield any further constraints on the origin of the seismicity that poses threats to the local populations residing on this hazardous island.

Analysis on heat transfer enhancement mechanism in a cross-wavy primary surface heat exchanger based on advection thermal resistance method

This paper numerically investigates the flow and heat transfer characteristics in the primary surface heat exchanger (PSHE) with cross-wavy (CW) structures. The comprehensive performance affected by hydraulic diameters is evaluated. Moreover, the airflow shuttling behavior at the mixing area of CW-type PSHE is discussed, showing rapid heat transfer enhancement. The advection thermal resistance method and local thermal resistance analysis is proposed, while the impacts of longitudinal pitch and flowrates are considered. Results show that the case with a large hydraulic diameter displays much better comprehensive performance at lower flowrates. When raising the hydraulic diameter from 1.58 mm to 15.8 mm, the heat transfer rate per unit pumping power grows by 36.1 %. However, the priority of large channel is gradually disappeared after increasing the flowrates. Meanwhile, the larger longitudinal pitch of the CW channel may result in pronounced improvement on the heat transfer performance due to the presence of airflow shutting behavior at the mixing area as well as the secondary flow near the channel boundary layers. When no airflow shuttling exists, very high advection thermal resistance region can be observed due to the formation of boundary layers. It can be recognized that the case with airflow shuttling behavior can display similar heat transfer improvement compared to that with increasingly high Reynolds numbers, yet the pressure loss is rarely increased.

Alternative splicing of ALDOA confers tamoxifen resistance in breast cancer.

The cancer-associated alternative splicing (AS) events generate cancer-related transcripts which are involved in uncontrolled cell proliferation and drug resistance. However, the key AS variants implicated in tamoxifen (TAM) resistance in breast cancer remain elusive. In the current study, we investigated the landscape of AS events in nine pairs of primary and relapse breast tumors from patients receiving TAM-based therapy. We unrevealed a notable association between the inclusion of exon 7.2 in the 5'untranslated region (5'UTR) of ALDOA mRNA and TAM resistance. Mechanistically, the inclusion of ALDOA exon 7.2 enhances the translation efficiency of the transcript, resulting in increased ALDOA protein expression, mTOR pathway activity, and the promotion of TAM resistance in breast cancer cells. Moreover, the inclusion of exon 7.2 in ALDOA mRNA is mediated by MSI1 via direct interaction. In addition, elevated inclusion of ALDOA exon 7.2 or expression of MSI1 is associated with an unfavorable prognosis in patients undergoing endocrine therapy. Notably, treatment with Aldometanib, an ALDOA inhibitor, effectively restrains the growth of TAM-resistant breast cancer cells in vitro and in vivo. The present study unveils the pivotal role of an AS event in ALDOA, under the regulation of MSI1, in driving TAM resistance in breast cancer. Therefore, this study provides a promising therapeutic avenue targeting ALDOA to combat TAM resistance.

Identification of a Promising Novel Genetic Source for Rice Root-Knot Nematode Resistance through Markers Associated with Trait-Specific Quantitative Trait Loci.

Direct-seeded rice (DSR) is gaining popularity among farmers due to its environmentally safe and resource-efficient production system. However, managing the rice root-knot nematode (RRKN), Meloidogyne graminicola, remains a major challenge in DSR cultivation. Developing genetic resistance is a pragmatic and effective approach compared to using hazardous pesticides. Pusa Basmati 1121 (PB1121) is the most popular Basmati rice variety, but it is highly susceptible to RRKN. In contrast, Phule Radha (PR) has shown highly resistant reaction to RRKN, as reported in our earlier study. We generated an F2:3 population from the cross of PB1121/PR and evaluated it for RRKN resistance-related traits under artificial inoculation conditions. The distribution pattern of traits in the F2:3 population indicated that resistance may be governed by a few major-effect genes and many minor-effect genes. The molecular markers reported to be associated with QTLs governing RRKN resistance traits were used to test in the current population. Although the simple linear regression identified significant associations between the markers and RRKN resistance-associated traits, these associations were spurious as the LOD score was below the threshold limit. This indicates that PR possesses novel genomic regions for resistance to RRKN as it does not possess any of the earlier reported QTLs.

Genetic Dissection of ToLCNDV Resistance in Resistant Sources of Cucumis melo.

Tomato leaf curl New Delhi virus (ToLCNDV) is a begomovirus causing significant melon (Cucumis melo) crop losses globally. This study aims to map the ToLCNDV resistance in the PI 414723 melon accession, previously identified and characterized through phenotypic studies, thereby exploring shared genomic regions with the established resistant source WM-7. In the present study, WM-7 and PI 414723 were crossed with the susceptible accessions 'Rochet' and 'Blanco' respectively, to generate F1 hybrids. These hybrids were self-pollinated to generate the populations for mapping the ToLCNDV resistance region and designing markers for marker-assisted selection. Disease evaluation included visual symptom scoring, viral-load quantification and tissue printing. Genotyping-by-sequencing and SNP markers were used for quantitative trait loci (QTL) mapping. For genetic analysis, qPCR and bulked segregant RNA-seq (BSR-seq) were performed. Gene expression was assessed using RNA-seq, and qRT-PCR was used for confirmation. The research narrows the candidate region for resistance in WM-7 and identifies overlapping QTLs on chromosome 11 in PI 414723, found in the region of the DNA primase large subunit. BSR-seq and expression analyses highlight potential regulatory roles of chromosome 2 in conferring resistance. Differential expression was confirmed for six genes in the candidate region on chromosome 2. This study confirms the existence of common resistance genes in PI 414723 and WM-7.