SEARCH · Search PubMed

Results for “Transcriptomic analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

PubMed2025

Genomic and Immune Landscape of Pancreatic Ductal Adenocarcinoma Associated with Germline Pathogenic Variants in ATM.

PURPOSE: Germline pathogenic variants (PV) in ATM increase the risk of pancreatic ductal adenocarcinoma (PDAC), but the underlying tumor biology of PDAC associated with germline PV in ATM has not been adequately explored. EXPERIMENTAL DESIGN: Whole-genome, whole-exome, and RNA sequencing were performed on PDAC tumors from 25 germline ATM PV carriers diagnosed at Mayo Clinic between 2007 and 2017. Somatic and copy-number alterations, mutational signatures, transcriptomic subtypes, and the immune landscape were evaluated. RESULTS: High-quality whole-exome and whole-genome sequencing were obtained from 21 and 15 tumors, respectively. Biallelic inactivation of ATM was observed in 87%, KRAS PV in 90%, CDKN2A homozygous loss in 60%, and TP53 alterations in <10% of these tumors. A predominant clock-like mutational signature was present in all samples. Whole-transcriptome analysis identified that the aberrantly differentiated endocrine exocrine subtype accounted for 18% of PDAC and was consistently associated with >5-year overall survival. In addition, a 28-gene expression-based signature associated with overall survival was identified and further validated in The Cancer Genome Atlas cohort. Immune landscape analysis through CODEX identified enriched CD4 T-helper cell/tumor interactions and reduced B7H3-high cell/tumor interactions in ATM PV carriers compared with noncarriers. CONCLUSIONS: The observed absence of TP53 PV and enrichment for CDKN2A alterations in ATM tumors, along with differences in the mutational signatures, transcriptomic subtypes and immune landscape, improve our understanding of the mechanistic pathways involved in PDAC development in germline ATM PV carriers and help identify potential targeted therapeutic strategies.

Humans↗

PubMed2025

Transcriptional profiling of Hutchinson-Gilford Progeria patients identifies primary target pathways of progerin.

Hutchinson Gilford Progeria Syndrome (HGPS) is an ultra-rare pediatric premature aging disorder. The disease is caused by a point mutation in the LMNA gene leading to the production of the dominant-negative progerin isoform of the nuclear envelope protein lamin A. Disease severity and progression amongst the population of ~140 known patients is variable. Most of the mechanistic insights into the disease have come from studies using cellular or mouse models of HGPS. To probe the clinical relevance of previously implicated cellular pathways and to address the extent of gene expression heterogeneity between patients, we have performed transcriptomic analysis of a comprehensive set of HGPS patients. We find misexpression of several cellular pathways across the patient population, particularly of multiple signaling pathways as well as the Unfolded Protein Response (UPR) and mesodermal cell fate specification. Variability amongst individual patients was limited, with misregulation of the major pathways observed in most patients. Comparing the transcriptome of patients with an inducible HGPS cell model, we distinguished immediate-early cellular response pathways from secondary adaptive pathways and identified mTORC1, the UPR, UV response, apoptosis and TNFα signaling via NF-κB as primary targets of the disease-causing progerin protein.

Hutchinson-Gilford Progeria Syndrome↗

PubMed2026

Microplastics and nanoplastics-related genes signature predicts prognosis in pancreatic ductal adenocarcinoma and functional validation of interleukin 1 alpha.

BACKGROUND: Microplastics and nanoplastics (MNPs), as emerging environmental pollutants, have garnered significant attention from the global scientific community due to their potential threats to human health, particularly their association with the occurrence and development of cancer. The goal of our study is to create a predictive marker for pancreatic ductal adenocarcinoma (PAAD) based on MNPs-related genes, with the purposes of predicting survival outcomes and assessing the tumor immune microenvironment. METHODS: Using multi-cohort data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and International Cancer Genome Consortium (ICGC), we assessed the association between MNPs and PAAD prognosis through the Xiantao Academic (https://www.xiantao.love/). The development of a prognostic signature was followed by an assessment of its significance through the Kaplan-Meier method, time-dependent receiver operating characteristic (ROC), and decision curve analysis (DCA). The validity of the risk model was confirmed through the ICGC and GSE71729 cohorts. The model was then assessed for levels of tumor immune infiltration. To explore MNPs-related genes expression characteristics within immune cells in PAAD, we performed single-cell RNA sequencing and spatial transcriptomics analysis through the Sparkle Platform (https://grswsci.top/). Finally, in vitro experiments were conducted to investigate the biological function of interleukin 1 alpha (IL1A). RESULTS: A four-gene signature comprising XDH, IL1A, KIF20A, and ASPM, based on MNPs, was developed to stratify PAAD patients into two distinct risk groups. The high-risk group showed a significantly poorer prognosis. A similar trend was verified in the external cohorts ICGC and GSE71729. The signature risk score affected immune cell infiltration in the PAAD microenvironment. The infiltration of B cells, CD8+ T cells, cytotoxic cells, immature dendritic cells (iDCs), mast cells, plasmacytoid dendritic cell (pDC), T cells, Tem cells, T follicular helper (TFH) cells, and T helper 17 (Th17) cells had a positive correlation with the low-risk group. In contrast, high-risk patients tended to have increased number of T helper (Th2) cells and higher expression of SIGLEC15, CD274, IGSF8. Knockdown of IL1A in PAAD cells inhibited their tumor proliferation ability in vitro. CONCLUSIONS: Using MNPs-related genes, we built a prognostic model for PAAD, revealing that patients with high-risk scores are likely to have a worse prognosis. This model is designed to develop personalized treatment strategies tailored to the specific needs of each patient, thereby improving clinical outcomes for PAAD patients. Furthermore, IL1A could be a promising therapeutic candidate for PAAD.

Microplastics↗

PubMed2025

Mutation of strigolactone biosynthetic gene DWARF 17 impairs the responses of rice tillering to N supply.

Tiller number is one important parameter for rice yield and is influenced by both strigolactone (SL) and nitrogen (N). However, how SL and N interact to regulate the tiller outgrowth in rice is unclear. In this study, we isolated a multi-tillering mutant, tin, from an ethyl methanesulfonate (EMS)-mutagenized population of Wuyunjing 7, a japonica cultivar. The tin mutant exhibited low sensitivity to varying N concentrations during the tiller development. Through bulk segregation analysis (BSA), we identified a missense mutation located in the exon of DWARF 17 (D17), a key gene involved in SL biosynthesis. Complementation experiments confirmed that D17 is responsible for the tin tiller phenotype, and exogenous application of the SL analogue GR24 restored the tiller response of tin to N. Transcriptome analysis further revealed that D17 and SL regulate the tiller response to N by modulating the expression of SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes and ammonium transporter genes. These findings elucidate the mechanism by which SL and N coordinate to regulate rice tillering growth, providing valuable insights for optimizing rice plant architecture to enhance yield potential.

Oryza↗

PubMed2025

Fine mapping of the dominant female sterility gene and novel model of hybrid seed production in cabbage (Brassica oleracea L. var. capitata).

Hybrid breeding based on male sterility requires the removal of male parents, which is time- and labor-intensive; however, the use of female sterile male parent can solve this problem. In the offspring of distant hybridization between Brassica oleracea and Brassica napus, we obtained a mutant, 5GH12-279, which not only fails to generate gynoecium (thereby causing female sterility) but also has serrated leaves that could be used as a phenotypic marker in seedling screening. Genetic analysis revealed that this trait was controlled by a single dominant gene. Further analysis revealed that Bo2g005230, an orthologous gene of LATE MERISTEM IDENTITY1 (LMI1) in Arabidopsis, was predicted as the candidate gene and was renamed BoLMI1c. Sequence analysis revealed that homoeologous exchange (HE) occurred within the BoLMI1c gene body of 5GH12-279, which resulted in the generation of a novel fusion transcript. Two pairs of primers, N5230-1F/1R and N5230-2F/2R, were designed and successfully used for the identification of different genotypes of BoLMI1c. Transcriptome analysis revealed that BoLMI1c orchestrates the expression of several related biological processes and transcription factors. Furthermore, we found that self-pollination with mason bees produced no seeds in 5GH12-279, whereas the near-isogenic line 5GH12-170 produced seeds that were normal. Therefore, a new labor-saving hybrid seed production system with no need to remove the male parents, which is especially important for mechanized harvest in the future, has been proposed. Our study provides a valuable source of dominant female sterility and suggests the potential utilization of the female sterile line in hybrid breeding for mechanized harvest.

Plant Infertility↗

PubMed2025

Staphylococcus aureus COL: An Atypical Model Strain of MRSA That Exhibits Slow Growth and Antibiotic Tolerance due to a Mutation in PRPP Synthetase.

Methicillin-resistant Staphylococcus aureus (MRSA) has been a pathogen of global concern since its emergence in the 1960s. As one of the first MRSA strains isolated, COL has become a common model strain of S. aureus. Here we report that COL is, in fact, an atypical strain of MRSA that exhibits slow growth and multidrug tolerance. Genomic analysis identified three mutated genes in COL (rpoB, gltX and prs) with links to tolerance. Allele swapping experiments between COL and the closely-related, nontolerant Newman strain uncovered a complex interplay between these genes. However, Prs (phosphoribosyl pyrophosphate [PRPP] synthetase) accounted for most of the growth and tolerance phenotype of COL. Biochemical and transcriptomic analysis revealed that COL does not exhibit slow growth as a result of partial stringent response activation, as previously proposed. Instead, the COL Prs mutation greatly reduces the PRPP synthetase activity of the enzyme and leads to downregulation of pyrimidine, histidine, and tryptophan synthesis, three pathways that rely on PRPP. Overall, our findings indicate that COL is an atypical, antibiotic-tolerant strain of MRSA whose isolation predates the previous first report of tolerance among clinical isolates. Characterization of clinical Prs mutations and their relationship with tolerance requires further investigation.

Methicillin-Resistant Staphylococcus aureus↗

PubMed2026

Muscular fiber properties and multi-omics investigation of larval and adult locomotor muscle in Microhyla fissipes.

During metamorphosis, Microhyla fissipes undergoes a critical transition from an aquatic to a terrestrial lifestyle, accompanied by significant remodeling of skeletal muscle. Notably, larval tail muscle degenerates, while adult hindlimb muscle develops. However, the molecular mechanisms that orchestrate these muscle type-specific adaptations to the changing environment remain unclear. In this study, histological observation, transcriptomics, and metabolomics were integrated to compare locomotor muscles from two stages: larval muscle from tail versus adult muscle from hindlimb. Our results revealed that adult muscle fibers exhibited reduced diameter and shorter sarcomere length compared to those of tadpoles. Transcriptomic analysis identified 4103 differentially expressed genes (DEGs), including 2182 up-regulated and 1921 down-regulated genes. Up-regulated genes were mainly involved in energy metabolism and cellular homeostasis pathways, including PPAR signaling and oxidative phosphorylation, whereas down-regulated genes were associated with carbohydrate metabolism and cell proliferation pathways, such as glycolysis/gluconeogenesis and PI3K-Akt signaling. Metabolic profiling indicated a metabolic shift from anaerobic to aerobic energy production, with 57 differential metabolites identified, mainly involved in protein metabolism and insulin-related pathways. Integrated multi-omics analysis further highlighted the AMPK and FoxO signaling pathways play key roles in this process. In conclusion, our findings demonstrate that the metabolic and structural differences between larval and adult skeletal muscles are mediated by AMPK- and FoxO-dependent signaling pathways, providing novel insights into the molecular mechanisms underlying adaptive development and locomotor transition in anuran amphibians.

Animals↗

PubMed2025

Integrating necroptosis and immune landscapes: a multi-omics-derived NecropImmScore stratifies prognosis and therapy in ovarian cancer.

BACKGROUND: Ovarian cancer (OC) remains the deadliest gynecologic malignancy, largely due to its immunosuppressive tumor microenvironment (TME) and resistance to therapy. Necroptosis, a regulated lytic cell death pathway mediated by the RIPK1-RIPK3-MLKL axis, can trigger immunogenic cell death, but its specific role in shaping the OC immune landscape and its clinical translation potential are posorly understood. METHODS: We employed multi-omics analysis (transcriptomics, genomics, clinical data) from TCGA-OV (n = 380), ICGC OV-AU, and IMvigor210 cohorts, combined with rigorous in vitro functional validation using OC cell lines (SKOV3, HEY), macrophages (THP-1 derived), and T cells (Jurkat). Computational immunology approaches (ESTIMATE, CIBERSORT, ssGSEA) quantified immune infiltration. We identified MLKL-associated immune genes, performed survival analysis (Kaplan-Meier, Cox regression), and constructed a necroptosis-immune signature (NecropImmScore) using consensus clustering and PCA of 102 prognostic genes. Drug sensitivity was predicted via pRRophetic and CellMiner. RESULTS: MLKL emerged as a protective prognostic biomarker (p = 0.018), significantly correlated with enhanced immune infiltration (ImmuneScore, StromalScore, ESTIMATEScore; p < 2.22e-16), M1 macrophage polarization (p = 0.006), activated CD4 + T cells (p = 0.003), and elevated immune checkpoint expression (PD-L1, CTLA4, LAG3, TIGIT). In vitro, MLKL overexpression in OC cells promoted M1 polarization (p < 0.05), activated Jurkat T cells (upregulated CCR4/5/7/9, CD69, CD3D/E, GZMB; p < 0.05), and induced key chemokines (CXCL9/10/11/13) critical for immune cell recruitment. Integration of MLKL-related and immune-related DEGs (n = 632) revealed enrichment in T-cell activation, chemokine signaling, and antigen presentation pathways (FDR < 0.05). Consensus clustering based on 102 survival-associated genes defined three molecular subtypes (Clusters A-C) with divergent survival (p = 0.019), necroptosis activity, and immune infiltration (Cluster C: best prognosis, highest MLKL/ImmuneScore). The derived NecropImmScore robustly stratified patients: high-score correlated with superior overall survival (TCGA: p < 0.001; ICGC: p = 0.014), inflamed TME phenotype, elevated checkpoint expression, and improved response to anti-PD-L1 in IMvigor210. Critically, high NecropImmScore predicted higher BRCA1 mutation frequency (AUC = 0.802), synergy with BRCA1 status for prognosis, higher homologous recombination deficiency (HRD) score, sensitivity to cisplatin (p = 0.014), paclitaxel (p = 0.016), gemcitabine (p = 0.017), and provided superior prognostic stratification when combined with TMB and HRD score (p < 0.001). CONCLUSION: This study establishes MLKL as a master regulator of anti-tumor immunity in OC, driving chemokine-mediated immune cell recruitment and TME reprogramming. The novel NecropImmScore is a multifaceted biomarker that effectively predicts prognosis, immunotherapy response, BRCA1 deficiency, and chemosensitivity, offering significant potential for guiding precision therapeutic strategies in OC.

Humans↗

PubMed2026

Nitric oxide enhances SlSPL10-mediated transcriptional repression of carotenoid synthesis genes to delay tomato fruit carotenoid accumulation.

Nitric oxide (NO) inhibits climacteric fruit ripening, but its mechanisms remain elusive. Here, S-nitrosoglutathione (GSNO, a NO donor) reduces carotenoid accumulation in tomato fruit, confirming NO's role as carotenoid biosynthesis suppressor. Transcriptome analysis identified SlSPL10 (SQUAMOSA promoter binding protein-like 10) as a key player during this process. Genetic evidence further revealed that SlSPL10 negatively regulates carotenoid synthesis. Moreover, GSNO fails to suppress carotenoid synthesis in slspl10 mutant fruit, in contrast to wild-type fruit, highlighting the involvement of SlSPL10 in NO-inhibited carotenoid synthesis. Transcriptomic profiling of slspl10 mutant fruit showed that both NO and SlSPL10 regulate key carotenoid synthesis genes (SlGPS, SlPDS, SlZDS, SlZISO, and SlCRTISO). SlSPL10 directly binds to the promoters of these genes to repress their transcription, and NO enhances the transcriptional inhibition of SlGPS, SlZISO, and SlCRTISO. These three genes are indispensable for SlSPL10's role in NO-mediated carotenoid suppression. Collectively, NO enhances SlSPL10-mediated repression of carotenoid biosynthesis gene expression, reducing carotenoid accumulation in tomato fruit.

Solanum lycopersicum↗

PubMed2026

Paired analysis of primary adenoid cystic carcinoma and derived cell lines reveals a mesenchymal and stem-like shift associated with therapy resistance.

Adenoid cystic carcinoma (ACC) is a salivary gland malignancy characterized by slow but persistent growth, frequent local recurrence, and late metastatic progression. Patients with unresectable, recurrent, or metastatic disease have limited therapeutic options. Efforts to identify effective therapeutic targets have been hindered by the limited availability of well-characterized ACC models. In this study, we established 11 ACC cell lines and performed RNA sequencing of nine cell lines and their matched primary tumors to evaluate the preservation and evolution of molecular and lineage-associated characteristics during cell line establishment. Comparative transcriptomic analysis revealed reduced epithelial and luminal differentiation programs in the cell lines, accompanied by enrichment of myoepithelial, EMT-, and cancer stem cell-associated transcriptional programs. Digital deconvolution and single-sample gene set enrichment analysis supported enrichment of hybrid EMT/stem-like states during in vitro propagation, while comparison with publicly available primary-recurrent ACC data demonstrated partial preservation of recurrence-associated plasticity and invasion programs. Protein-level validation of representative epithelial, myoepithelial, EMT, and stemness markers supported the major transcriptomic changes. In addition, a cell line with a higher stemness signature showed reduced sensitivity to cisplatin. Together, these findings indicate that ACC cell line establishment is associated with transcriptional reprogramming and enrichment of plastic, EMT/stem-like states while retaining selected ACC lineage characteristics. These models provide experimentally tractable platforms for investigating ACC progression, therapeutic response, and mechanisms of treatment resistance.

Adenoid cystic carcinoma↗

PubMed2025

Evolutionary engineering and molecular characterization of an antimycin A-resistant Saccharomyces cerevisiae strain: the key role of pleiotropic drug resistance (PDR1).

Antimycin A, an antifungal agent that inhibits mitochondrial respiration, provides a useful model for studying resistance mechanisms. Antifungal resistance is an escalating clinical concern with limited treatment options available. To understand the molecular mechanisms of antimycin A resistance, a genetically stable, antimycin A-resistant Saccharomyces cerevisiae strain was successfully developed for the first time through an evolutionary engineering strategy, based on long-term systematic application of gradually increasing antimycin A stress in repetitive batch cultures without prior chemical mutagenesis. Comparative whole genome resequencing analysis of the evolved strain ant905-9 revealed two missense mutations in PDR1 and PRP8 genes involved in pleiotropic drug resistance and RNA splicing, respectively. Using CRISPR/Cas9 genome editing tools, the identified mutations were introduced individually and together into the reference strain, and it was confirmed that the Pdr1p.M732R mutation alone confers antimycin A-resistance in S. cerevisiae. Comparative transcriptomic analysis of the reverse-engineered Pdr1p.M732R strain showed alterations in PDR (pleiotropic drug resistance), transmembrane transport, vesicular trafficking, and autophagy pathways. Our results highlight the potential key role of PDR1 in antifungal drug resistance. This study provides new insights into mitochondrial drug resistance and the adaptive potential of yeast under respiratory stress.

Saccharomyces cerevisiae↗

PubMed2026

Third-generation whole-genome sequencing reveals the role of CNTNAP2 as a tumor suppressor gene in high-risk neuroblastomas.

BACKGROUND: Neuroblastoma is a common and aggressive pediatric sympathetic nervous system tumor. Genomic structural variants (SVs) contribute substantially to neuroblastoma, yet remain under-characterized in high-risk neuroblastomas. We aimed to elucidate neuroblastoma pathogenesis using third-generation whole-genome sequence high-risk cases to identify driver aberrations and explore potential therapeutic strategies. METHODS: We analyzed third-generation whole-genome sequencing data of 20 high-risk neuroblastoma samples and combined the findings with those obtained from the analysis of clinical samples, in vitro models, and public datasets. RESULTS: The contactin-associated protein-like 2 (CNTNAP2) gene was observed to be frequently aberrated because of structural variants in high-risk neuroblastoma samples. CNTNAP2 expression was significantly correlated with favorable histology and could be used to predict prognosis using clinical samples and neuroblastoma datasets. Overexpression and knockdown experiments and transcriptomic analysis revealed that CNTNAP2 was primarily involved in neuronal differentiation and axon guidance pathways; moreover, CNTNAP2 was required for neuroblastoma differentiation and affected cancer stemness. Immunoprecipitation and mass spectrometry revealed that CNTNAP2 interacted with cytoskeletal proteins like drebrin 1 (DBN1) and myosin-heavy chain 9 (MYH9). CNTNAP2 dynamically reorganises actin and microtubules for DBN1-mediated neuronal differentiation. CNTNAP2 also reduces CTNNB1 transcription and β-catenin pathway activation by inhibiting MYH9 nuclear translocation. CNTNAP2 overexpression in neuroblastoma cell lines resulted in cell cycle arrest, decreased cell proliferation and metastasis. CONCLUSIONS: The recurrent loss of CNTNAP2 in neuroblastoma contributes to an aggressive phenotype by impairing neuronal differentiation and increasing cancer stemness. These findings may serve as a foundation for developing therapeutic strategies to overcome barriers to differentiation.

Humans↗

PubMed2025

ves1α genes expression is the major determinant of Babesia bovis-infected erythrocytes cytoadhesion to endothelial cells.

Babesia bovis causes the most pathogenic form of babesiosis in cattle, resulting in high mortality in naive adults. This parasite invades red blood cells (RBCs) within the bovine hosts where they multiply and produce clinical disease. Babesia bovis exports numerous proteins into invaded RBCs changing its properties. Thus, the infected RBCs (iRBCs) are capable to cytoadhere in the microvasculature of internal organs and brain, leading to respiratory distress, neurologic signs, and mortality. Variant Erythrocyte Surface Antigen 1 (VESA1) is one of those exported proteins by B. bovis which represents a major virulence factor due to its central role in immune evasion by antigenic variation and intravascular parasite sequestration. VESA1 is a heterodimer protein encoded by ves1α and ves1β multigene family and localized on the ridges, the focal point for cytoadhesion. To gain further insights into the molecular mechanisms of cytoadhesion of B. bovis, we panned the parasites with bovine brain microvasculature endothelial cells, which resulted in obtaining several clones with different cytoadherence abilities. The transcriptome analysis of 2 high and 2 low cytoadherent clones revealed that ves1α sequences were diversified, likely resulting from genomic recombination. On the other hand, ves1β sequences were almost identical among these 4 clones. Insertion and expression of ves1α of a clone with high binding into ef-1α locus of a low binding clone increased cytoadherence confirming the role of ves1α suggested by our transcriptome data. Whole genome sequencing of cytoadherent clones revealed active locus of ves1 on chromosome 2. These results suggest that VESA1a proteins encoded by ves1α genes determine the cytoadherence strength of B. bovis and they are in the active site for recombination.

Animals↗

PubMed2026

Comparative metabolomic and transcriptomic profiling of flavonoid diversity and antioxidant capacity in three Isatis species.

Flavonoids are key bioactive compounds in plants with significant health benefits. This study employs an integrated multi-omics approach to investigate flavonoid diversity and antioxidant capacity across three Isatis species: I. oblongata, I. tinctoria, and I. indigotica. Metabolomic profiling identified 200 flavonoids, with glycosides being the most abundant class. I. tinctoria exhibited the highest total flavonoid content and antioxidant activity, strongly correlated with the accumulation of 53 core differential flavonoid metabolites, most of which were glycosylated derivatives. Transcriptomic analysis revealed coordinated upregulation of phenylpropanoid pathway genes and specific UDP-glycosyltransferases (UGTs) in I. tinctoria, providing a genetic basis for its enhanced glycoside production. The study establishes a clear genotype-metabolite-phenotype linkage, highlighting glycosylation as a key mechanism underlying flavonoid-driven antioxidant superiority in Isatis. Although the current evidence is primarily correlative, the consistent and strong associations across independent transcriptomic, metabolomic, and antioxidant datasets provide a robust foundation for this conclusion. These findings offer new insights into the metabolic evolution and regulatory networks of flavonoids, with implications for breeding and metabolic engineering of high-value medicinal plants.

Flavonoids↗

PubMed2003

Biotechnological manufacture of lysine.

L-Lysine has been manufactured using Corynebacterium glutamicum for more than 40 years. Nowadays production exceeds 600,000 tons per year. Based on conventionally bred strains, further improvement of lysine productivity has been achieved by genetic engineering. Pyruvate carboxylase, aspartate kinase, dihydrodipicolinate synthase, homoserine dehydrogenase and the specific lysine exporter were shown to be key enzymes for lysine production and were characterized in detail. Their combined engineering led to a striking increase in lysine formation. Pathway modeling with data emerging from 13C-isotope experiments revealed a coordinated flux through pentose phosphate cycle and tricarboxylic acid cycle and intensive futile cycling between C3 compounds of glycolysis and C4 compounds of tricarboxylic acid cycle. Process economics have been optimized by developing repeated fed-batch techniques and technical continuous fermentations. In addition, on-line metabolic pathway analysis or flow cytometry may help to improve the fermentation performance. Finally, the availability of the Corynebacterium glutamicum genome sequence has a major impact on the improvement of the biotechnological manufacture of lysine. In this context, all genes of the carbon flow from sugar uptake to lysine secretion have been identified and are accessible to manipulation. The whole sequence information gives access to post genome technologies such as transcriptome analysis, investigation of the proteome and the active metabolic network. These multi-parallel working technologies will accelerate the generation of knowledge. For the first time there is a chance of understanding the overall picture of the physiological state of lysine overproduction in a technical environment.

Bioreactors↗

PubMed2026

Metabolome-driven rhizosphere microbiome assembly determining the health of medicinal herb (Angelica sinensis) against root rot.

BACKGROUND: The rhizosphere-associated microbiota plays a crucial role in plant responses to disease stress. Plant secondary metabolites are recognized as crucial mediators in the assembly of rhizosphere microbial communities, particularly by enhancing the colonization of beneficial microorganisms. Despite this recognized importance, a deeper understanding of how such metabolome-driven microbiome assembly specifically determines plant resistance against soil-borne diseases is still lacking. RESULTS: Here, we focused on the widely planted medicinal plant Angelica sinensis and demonstrated that root rot-diseased rhizosphere soils (DRS) exhibited a higher relative abundance of Fusarium and a lower relative abundance of Streptomyces compared to healthy rhizosphere soils (HRS). Shotgun metagenomic sequencing revealed that metabolism-associated genes, particularly those related to steroid degradation, are significantly enriched in HRS samples. Subsequent genome and functional gene analysis of Streptomyces revealed that the steroid degradation-related genes are associated with rhizosphere colonization in hosts. Rhizosphere Streptomyces S15 directly antagonized Fusarium and enhanced the root resistance of A. sinensis. Comparative metabolomics showed that A. sinensis plants from HRS secreted more lipid and lipid-like molecules than those from DRS, especially sterol lipids and long-chain fatty acids, which promoted the growth of Streptomyces S15 isolates. Transcriptome analysis validated that the lipid hormones are essential for sporulation, biofilm formation, and streptomycin biosynthesis of S15 strain. Finally, exogenous application of synbiotics (lipid prebiotics and S15) to A. sinensis resulted in the enrichment of S15-homologous Streptomyces amplicon sequence variant (ASV), further establishing beneficial bacterial communities in Fusarium-stressed rhizospheres. CONCLUSIONS: Our study proposes that A. sinensis recruits steroid-metabolizing Streptomyces species by exuding key lipid compounds (i.e., methyl jasmonate and brassinolide) to combat Fusarium root rot. This study provides novel insights into using functional synbiotics as a promising strategy for manipulating plant-microbiome interactions to promote sustainable agriculture. Video Abstract.

Rhizosphere↗

PubMed2026

Cis-regulatory variation in the MdCKX6 promoter is associated with allele-specific expression and fruit size in apple.

Fruit size is a key determinant of apple fruit quality and market value and is strongly influenced by phytohormone-regulated cell proliferation and expansion during early fruit development. Cytokinin oxidase/dehydrogenase (CKX) enzymes regulate cytokinin homeostasis by irreversibly degrading active cytokinins, but the contribution of natural variation in CKX genes to fruit size remains poorly understood. Here, we identified MdCKX6 as a candidate regulator of fruit growth in apple (Malus domestica). MdCKX6 exhibited pronounced allele-specific expression during fruit development in the cultivar 'Royal Gala'. Sequence analysis identified a promoter SNP associated with differential promoter activity and allele-specific expression. Genotyping of diverse apple cultivars and wild Malus accessions revealed a significant association between MdCKX6 promoter genotype and fruit size. Cultivars carrying low-expression alleles produced larger fruits, whereas high-expression alleles were associated with smaller fruits. To investigate gene function, MdCKX6 was overexpressed in tomato, resulting in reduced fruit size. Histological analyses of the transgenic tomato fruit revealed smaller pericarp cells. Transcriptome analysis of transgenic fruits revealed widespread changes in genes associated with cell-cycle regulation, cell wall modification, hormone-related processes, and transcriptional regulation. Together, these results identify MdCKX6 as a potential negative regulator of apple fruit growth and reveal an association between cis-regulatory variants, gene expression, and fruit size. This study provides new insights into the role of cytokinin metabolism in fruit development and highlights regulatory variation in MdCKX6 as a potential target for apple breeding.

Malus↗

PubMed1999

Selection at the wobble position of codons read by the same tRNA in Saccharomyces cerevisiae.

The transfer RNA gene complement of Saccharomyces cerevisiae was utilized for a whole-genome analysis of the deviation from a neutral usage of pyrimidine-ending cognate codons, that is, codons read by a single tRNA species having either inosine or guanosine as the first anticodon base. Mutational pressure at the wobble position was estimated from the base composition of the noncoding portion of the yeast genome. The selective pressure for translational efficiency was inferred from the degree of codon adaptation to tRNA gene redundancy and from mRNA abundance data derived from yeast transcriptome analysis. Amino acid conservation in orthologous comparisons with wholly sequenced microbial genomes was used to estimate translational accuracy requirements. A close correspondence was observed between the usage of wobble position pyrimidines and the frequency predicted by mutational bias. However, in the case of four cognate pairs (Gly: ggu/ggc; Asn: aau/aac; Phe: uuu/uuc; Tyr: uau/ uac) all read by guanosine-starting anticodons, we found evidence for a strong selective pressure driven by translational efficiency. Only for the glycine pair, wobble pyrimidine choice also appears to fulfill a translational accuracy requirement. Wobble pyrimidine selection is strictly related to the number of hydrogen bonds formed by alternative cognate codons: whenever a different number of hydrogen bonds can be formed at the wobble position, there is selection against six- or nine-hydrogen-bonded codon-anticodon pairs. Our results indicate that an intrinsic codon preference, critically dependent on the stability of codon-anticodon interaction and mainly reflecting selection for the optimization of translational efficiency, is built into the translational apparatus.

Codon↗