Globba racemosa, a Zingiberaceae species native to southern and southwestern China, the complete chloroplast genome of G. racemosa was sequenced and reported for the first time. The genome was 163,321 bp in total length, possess typical quadripartite structures that consist of a large single copy (LSC, 88,111 bp), a small single copy (SSC, 15,770 bp) and a pair of inverted repeats (IRs, 29,720 bp). The complete chloroplast genome contained 134 genes (87 protein-coding, 39 tRNA, 8 rRNA), with an overall GC content of 35.8%. phylogenetic analysis based on 10 chloroplast genomes indicated its close affinity to R. multiflora in Glolla. This newly reported chloroplast genome can provide fundamental genetic data for future research on the genus Globba.

TDP-43 dysfunction is thought to be central to ALS pathogenesis. Studying mutations in the gene which encodes TDP-43, TARDBP, provides a valuable opportunity to gain insight into how TDP-43 dysfunction alters cellular homoeostasis. Our group has previously developed a TDP-43M337V mouse embryonic stem cell-derived motor neuron (mESC-MN) model, which expresses a single copy of the human TARDBP gene expressing the pathogenic M337V mutation at low levels. Here, we perform extensive phenotypic characterisation of this model, and show that TDP-43M337V leads to reduced MN viability, impaired axonal transport and reduced basal glycolysis compared to TDP-43WT controls. Altered neuronal viability and function occurs in the absence of TDP-43 mislocalisation or aggregation, suggesting 'proteinopathy' is downstream of these ALS-relevant phenotypes. These findings provide further support for a link between TDP-43 dyshomeostasis, cellular bioenergetics and axonal transport and suggest these pathways warrant further investigation as targets for therapeutic intervention.

Onthophagus binodis is a coprophagous scarab beetle native to southern Africa. This species and many others in the tribe Onthophagini have been introduced to farms across multiple continents in the context of cattle pasture management efforts. The ecosystem services provided by this species, along with the amenability of comparative developmental and evolutionary studies in this clade, contribute to its role as an emerging insect model system. Here, we present sex-specific chromosomal-level genome assemblies for O. binodis generated from a combination of PacBio long reads and HiC chromatin conformation sequencing. The completeness of the 950.5 Mb female assembly and the 880.5 Mb male assembly is indicated by a contig length N50 of at least 58.6 Mb. BUSCO single copy and duplicated completeness scores were 99.0% and 0.9% for the female assembly and 97.4% and 2.1% for the male assembly. Gene modelling identified at least 15,403 gene models in each genome with an average transcript length of 1.6 kb. Comparative analyses with other Onthophagini genomes indicated a dramatic expansion of repetitive sequences, which now comprise over 75% of this species' genome and have driven the expansion of overall genome size to nearly twice that of close relatives. We combined the best-assembled chromosome-scale scaffolds from each sex to generate a hybrid reference assembly for this species. Comparative genomic analyses show that the 9 autosomes and the X chromosome identified here in O. binodis are likely conserved throughout Onthophagini. Our sex-specific sequencing approach allowed us to identify putative Y chromosome sequences in the male assembly via coverage mapping and k-mer abundance comparisons. These genomes will be of great value to the scientific community as resources for studying insect genome evolution, development, and ecology.

Abstract Background: Targeted therapies for metastatic castrate resistant prostate cancer (mCRPC) increasingly rely on genomic profiling, including liquid biopsy of circulating tumor DNA (ctDNA), to enable precision treatment. Integrating multi-patient ctDNA-derived molecular insights with deeply abstracted real-world clinical data offers the opportunity to improve biomarker identification, patient selection, and reverse translation. Methods: Data were obtained from the ConcertAI Translational360™ dataset. Specifically, mCRPC patients with overlapping liquid biopsy ctDNA testing results from Guardant Health were identified. Patient characteristics, timing of ctDNA testing, prior treatments, and the prevalence of specific mutations were described. Using all mCRPC patients in the cohort, treatment-agnostic univariate Cox proportional hazards models were trained on the 3 most frequent mutations and on maximum allele frequency. Results: Among 1,167 mCRPC patients from primarily community oncology practices (78.3%) with at least one ctDNA test, median age at mCRPC diagnosis was 68 (IQR: 60, 80) years; 72% of patients were white, 17% were Black, and 2% were Asian. The first ctDNA test occurred a median 2.2 years (IQR: 0.9, 5.0) after patients became castrate-resistant. For 200 patients with longitudinal testing, a median of 1.2 years (IQR: 0.6, 1.9) elapsed between the first and last ctDNA test. Treatment patterns shifted after ctDNA testing. Specifically, PARP inhibitor therapy increased from 5% of patients before ctDNA testing to 20% after ctDNA testing. Longitudinal changes in mutations were associated with treatment. Among patients who initiated PARP inhibitor therapy between their first and last ctDNA tests (n=22; median 5 prior lines of therapy (IQR: 3.2, 7.8)), the increase in mutation count was greater than in other patients: median increase of 8.5 unique mutations (IQR 5.0, 15.5) vs. 3 (IQR 0, 7.2), Wilcoxon rank-sum p<0.001. Forty-one distinct ctDNA genomic alterations were detected in 1% or more of mCRPC patients including single nucleotide variants (SNV), indel, splice, and copy number variants (CNV). The three most frequent genomic alterations — AR amplification (29%), EGFR amplification (11%), and AR p.L702H (11%) — were each associated with worse rwOS in univariate Cox proportional hazards models (p< 0.001; C-index: AR amplification = 0.61; EGFR amplification = 0.54; AR p.L702H = 0.53). By comparison, maximum allele frequency (MAF), a measure of total ctDNA burden, had greater discrimination for rwOS than the individual mutations (C-index = 0.64; hazard ratio per 1 SD increase = 1.41; 95% CI: 1.32-1.50). Conclusions: In this real world cohort of mCRPC patients with at least one ctDNA test, a shift toward targeted therapies occurred after the first ctDNA test and acquired mutations were apparent at the time of the subsequent ctDNA test. Both individual mutations and MAF were associated with rwOS, highlighting the opportunity to utilize real world datasets for translational research and investigation of novel biomarkers. Citation Format: Matthew S. Hall, Kathryn L. Penney, Jiemin Liao, Sean Gordon, Brooke Overstreet, Michael Rossi, Jennifer R. Rider. Utilization of liquid biopsy in metastatic castrate resistant prostate cancer (mCRPC): patient characteristics, treatment selection, and mutational status [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Innovations in Prostate Cancer Research and Treatment; 2026 Jan 20-22; Philadelphia PA. Philadelphia (PA): AACR; Cancer Res 2026;86(2_Suppl):Abstract nr A020.

IntroductionThe genus Drynaria, a member of the Polypodiaceae family, exhibits substantial medicinal and ornamental value. Although molecular biological studies have elucidated the phylogenetic relationships in Drynaria, the characteristics of its plastome and the mechanisms underlying its adaptive evolution remain inadequately understood.MethodsThis study performed a comprehensive comparative genomic analysis based on the plastomes of 15 Drynaria species. The research analyzed codon usage bias and identified positively selected genes within this genus. A well-supported phylogenetic tree was constructed using plastome data, and divergence times were measured at key nodes.ResultsThe analysis revealed that the plastomes of the 15 Drynaria species varied in size from 151,473 bp (D. speciosa) to 163,438 bp (D. parishii), each with 133 genes. Comparative analysis demonstrated conserved gene content, order, and orientation across all examined species, with no inversions or rearrangements except for a non-coding region rearrangement in the large single copy region of D. roosii and the small single copy region of D. meyeniana. Nucleotide diversity analysis identified seven hypervariable regions. The study detected 691 simple sequence repeats, 136 tandem repeats, and 750 dispersed repeats. Codon usage bias in Drynaria plastomes was predominantly influenced by natural selection. Phylogenetic reconstruction based on complete plastomes produced congruent topologies. Divergence time estimation suggested that Drynaria originated in the mid-Paleocene (59.75 Ma), with major diversification events occurring during the late Miocene (6–5 Ma). Selection pressure analysis revealed positive selection of petA and ycf3 in branch models, while ccsA, ycf1, and rpoC2 exhibited evidence of positive selection in branch-site models.DiscussionThese findings provide insights into the evolutionary adaptations and genomic features of this ecologically and economically significant fern genus.

Many organisms carry extra, non-essential chromosomes known as B chromosomes (Bs), which are selfishly transmitted at super-mendelian levels to offspring. This heightened transmission, termed drive, occurs during gametogenesis, usually in one of the two parents. In some cases, Bs can experience an opposing process, drag, which reduces their transmission. If these processes occur together in the same organism, one in each parental sex, then they may facilitate the spread of Bs while countering their accumulation in the genome to harmful levels. While previous studies have elucidated mechanistic aspects of B drive, little is known about drag or other factors that govern the inheritance of these selfish genetic elements. Here, we examined the inheritance of Paternal Sex Ratio (PSR), a single-copy B in the jewel wasp, Nasonia vitripennis, which is transmitted paternally to offspring. PSR drives by converting female-destined embryos into PSR-transmitting males. Using genetic manipulation, we produced exceptional PSR-carrying females, which were used to assess B transmission potential. We found that females transmit PSR at an unexpectedly low level compared to univalent chromosomes in other organisms. This reduced transmission stems from remarkable loss of PSR from the egg’s nucleus upon entry into meiosis, an effect that may be caused by an absence of microtubule-based spindle fibers in meiosis I-arrested wasp eggs. We also found that PSR is strictly limited to a single copy per genome, likely because wasps having two PSR copies die during development. Our findings reveal the successful inheritance of this selfish B chromosome involves its restriction to a single copy and hidden female meiotic drag in addition to strong paternal drive.

Ovarian cancer ranks sixth as the most common cancer and fifth as the most deadly malignancy among women worldwide. In addition, it places third among the most common gynecological cancers. Which proves that it is a significant medical problem worldwide. Most ovarian cancers (75-90%) are sporadic and arise from the accumulation of somatic mutations that are confined to the genome of the tumor tissue. However, about 10-25% of all ovarian cancer cases are hereditary. Most hereditary cases of ovarian cancer are associated with one of three genetic syndromes: hereditary breast and ovarian cancer syndrome (HBOC), hereditary ovarian site-specific cancer syndrome (HOC-ss) and hereditary non-polyposis-related colorectal cancer syndrome (HNPCC). Mutations in the BRCA1/BRCA2 underlie the majority of hereditary ovarian cancers and belong to the group of genes with high penetrance which means that carriers of their pathogenic variants have a high risk of developing ovarian cancer. Mutations in these genes are inherited in an autosomal dominant disorder, which means that inheriting a single copy of the mutated gene significantly increases the risk of developing this cancer. In contrast, about 5-10% of patients are carriers of pathogenic variants in other genes with moderate or low penetrance, such as ATM, CHEK2, PALB2 or BARD1. More than 75% of all ovarian cancers are detected at FIGO stages III and IV, in which the overall 5-year survival does not exceed 35%. Ovarian cancer is a heterogeneous disease that understanding the hereditary basis of this disease is crucial for its effective diagnosis, management and prevention. This review article aims to discuss the genetic basis of hereditary ovarian cancer, epidemiology, etiology and treatment options.

Castanea sativa, a species of high ecological and economic relevance in Europe, faces severe threats from root rot caused by Phytophthora cinnamomi. To explore genetic strategies for enhancing disease tolerance, we investigated the functional role of a chestnut gene homologous to Ginkgo biloba's ginkbilobin-2 (Cast_Gnk2-like), known for its antifungal properties. Using Agrobacterium tumefaciens-mediated transformation, the Cast_Gnk2-like gene was introduced into somatic embryos from two embryogenic chestnut lines. Transformation efficiency was genotype-dependent, and varied from 14.2% to 2.5%. Twelve independent transgenic lines were confirmed by PCR, and each was estimated to carry a single copy of the transgene. Gene expression analysis revealed significant Cast_Gnk2-like transcript levels in two transgenic lines. Following cold storage and germination treatment, viable transgenic plants were regenerated. Disease tolerance assays demonstrated that Cast_Gnk2-like overexpression significantly reduced root necrosis and symptom severity, indicating enhanced tolerance to P. cinnamomi. These findings highlight the potential of targeted gene overexpression to improve disease resilience in chestnut through genetic engineering.

Yellow wood sorrel (Oxalis stricta L.), also known as sourgrass, juicy fruit, or sheep weed, is a member of the Oxalidaceae family. Yellow wood sorrel is commonly considered a weed and while native to North America, it is distributed across Europe, Asia, and Africa. To date, only two other genomes from the Oxalidaceae family have been published, star fruit (Averrhoa carambola L.) and Oxalis articulata Savingy. Here, we present a chromosome-scale assembly for O. stricta, revealing its allotetraploid nature and synteny within its two subgenomes as well as synteny with A. carambola and O. articulata. Using Oxford Nanopore Technologies long-read sequences coupled with chromatin capture sequencing, we generated a 436 Mb chromosome-scale assembly of O. stricta with a scaffold N50 length of 36.2 Mb that is anchored to 12 chromosomes across the two subgenomes. Assessment of the final genome assembly using the Long Terminal Repeat Assembly Index yielded a score of 13.12 and assessment of Benchmarking Universal Single Copy Orthologs revealed 99.6% complete orthologs; both metrics are suggestive of a high-quality reference genome. Total repetitive sequence content in the O. stricta genome was 39.7% with retroelements being the largest class of transposable elements. Annotation of protein-coding genes yielded 61,550 high confidence genes encoding 115,089 gene models. Synteny between the two O. stricta subgenomes was present in 93 syntenic blocks containing 40,750 genes, of which, 76.47% were present in 1:1 syntenic relationships between the two subgenomes. The availability of an annotated chromosome-scale high quality genome assembly for O. stricta will provide a launching point to understand the high fecundity of this weed and provide further foundation for comparative genomics within the Oxalidaceae.

Cefiderocol (FDC) is regarded as a reserved therapeutic option for serious CRE infections. In an earlier study, we had reported a 9.9% FDC resistance in CRE isolates. In the present study, we are reporting the whole genome sequencing analysis findings of two FDC-resistant CRE (One E. coli and one K. pneumoniae). PBP3 insertions and mutations in the siderophore receptor cirA were the primary drivers of FDC resistance in E. coli. In K. pneumoniae, there was intact porin and a single copy of blaNDM-5, and a combination of β-lactamase and carbapenem resistance genes, including blaTEM- 1B, blaCTX-M-15,blaNDM-5 and blaOXA-181.

Fishes are frequently exposed to hypoxic stress, yet their tolerance to hypoxia varies significantly among species. The association between this variation and alterations in the hypoxia-inducible factor (HIF) pathway remains unclear. We discovered that otomorphs generally retain two Hif-1α paralogs (Hif-1αa and Hif-1αb), resulting from the teleost-specific genome duplication (TGD), whereas most euteleosts possess only a single Hif-1αa copy. In otomorphs, key mutations disrupt one conserved Leu-X-X-Leu-Ala-Pro (LXXLAP) motif in the oxygen-dependent degradation (ODD) domain of the Hif-1αa proteins. Molecular dynamics simulations revealed that these mutations impede the recognition of the critical proline residue by prolyl hydroxylase domain protein 2 (PHD2), suggesting enhanced normoxic stability of Hif-1αa. We also investigated the expression profiles of hif-1α and downstream genes in four fish species (two otomorphs and two euteleosts). In otomorphs, the hif-1αa genes were highly expressed specifically in the heart; concomitantly, two critical downstream genes, ldha and mct4, exhibited relatively high expression levels in vital tissues such as the heart, brain, and muscle. This coordinated expression pattern promotes a heightened glycolytic capacity and facilitates lactate shuttling in these tissues, thereby ensuring energy supply during hypoxic stress. Our integrated computational analyses indicate that otomorphs achieve enhanced hypoxia tolerance through the subfunctionalization of Hif-1α paralogs.

Apolipoprotein B (apoB) is essential for lipoprotein assembly and secretion and plays a central role in the development of cardiovascular disease and metabolic dysfunction-associated steatotic liver disease. Although apoB protein degradation during very-low-density lipoprotein maturation has been extensively studied, the regulation of APOB mRNA stability under physiological and pathological conditions remains unexplored. A forward genetic screen in randomly mutagenized mice identified HELZ2 (helicase with zinc finger 2) as a critical regulator of lipid metabolism. The metabolic effects of HELZ2 mutations or deficiency were evaluated in mice maintained on a chow diet or a high-fat diet. We also used a doxycycline-inducible, liver-specific HELZ2 overexpression model to test the sufficiency of hepatocyte Helz2 upregulation. Biochemical assays were used to assess HELZ2 binding to APOB mRNA and its role in APOB mRNA degradation, and the effect of HELZ2 modulation on atherosclerosis was examined in Apoe-/- and Ldlr-/- mouse models. We discovered a unique gain-of-function mutation in HELZ2 (L1833P, called Colby) that promotes hepatic lipid accumulation independently of changes in body weight on a standard chow diet. Mechanistically, HELZ2 binds APOB mRNA and degrades it through its helicase activity, ensuring tight control of hepatic apoB levels. The Colby mutation enhances HELZ2 helicase activity, resulting in marked reduction in Apob expression and increased hepatic lipid accumulation. Conversely, Helz2-deficient mice show increased Apob mRNA levels and reduced hepatic triglycerides on a high-fat diet. Notably, modest liver-restricted induction of HELZ2 was sufficient to decrease hepatic Apob mRNA and alter lipid handling, phenocopying the Helz2Colby state and supporting the gain-of-function mechanism. A single copy of the Helz2Colby mutation confers protection against atherosclerosis in Apoe-/- and Ldlr-/- mice. HELZ2 is a key regulator of APOB mRNA stability and lipid metabolism. Genetic or pharmacological modulation of HELZ2 activity represents a promising therapeutic strategy for cardiovascular disease and metabolic dysfunction-associated steatotic liver disease.

ABSTRACTSomatic differences in mitochondrial DNA (mtDNA) have been observed with aging and between brain regions for mutations, structural variation, and abundance, which are represented by single nucleotide variants (SNVs), large deletions, and copy number, respectively. We used bioinformatic methods to interrogate mtDNA changes and their relation to cortical and cerebellar aging using whole genome sequencing data from the North American Brain Expression Consortium. This dataset contained 292 unpaired postmortem samples from frontal cortex (n = 143) and cerebellum (n = 149), ranging in age from 0.4 to 100 years and without neurological diagnoses (i.e., controls). Our analyses included (a) evaluation of mtDNA copy number using fastMitoCalc; (b) quantification of large mtDNA deletions using Splice‐Break2; (c) analysis of homoplasmic and heteroplasmic SNVs; and (d) mitochondrial genome‐wide associations between SNVs and large deletions. For mtDNA deletions specifically, we expanded our previous analyses to include the predicted effects on mitochondrial complexes (I–V), mitochondrial‐derived microproteins, and tRNAs. MtDNA copy number significantly decreased in the cortex with age. MtDNA deletions increased in both brain regions with age, with a more dramatic slope in the cortex. These large deletions had significantly more effect on mitochondrial Complex I than other mitochondrial‐encoded complexes (III–V); likewise, deletions had significantly more effect on mtALTND4 and SHMOOSE than other annotated microproteins. Heteroplasmic SNVs increased with age in cortex but not cerebellum. Finally, three common SNVs (T14798C, G12372A, and C14766T) significantly associated with large mtDNA deletions (7816–14,807, 12,369–14,004, and 8775–14,771) and altered the length of the repeat sequence associated with the 5′ or 3′ breakpoint.

Gene duplication and loss play an important role in the evolution of the major histocompatibility complex (MHC). Variations in copy number and sequence diversity of MHC genes can have significant fitness consequences. Here, we characterized both MHC class I and class II genes in a group of parrots-lovebirds (Agapornis spp.) using cloning and sequencing, quantitative PCR, and depth-of-coverage (DoC) analysis with whole-genome re-sequencing data. We identified copy number variation in MHC class II genes, with A. roseicollis having a single MHCIIB gene copy, whereas A. canus possesses at least three gene copies. Conversely, the copy number of class I genes is invariable, with only one copy identified in each Agapornis species. Phylogenetic reconstructions revealed both concerted evolution and trans-species polymorphism of MHC genes. In both MHC class I and II genes, sequences from the recently diverged eye-ringed species (e.g., A. fischeri, A. personatus, and A. nigrigenis) and their sister species A. roseicollis showed an intercalating pattern with no species-specific clustering, consistent with trans-species polymorphism. In contrast, sequences from the early-diverged species (e.g., A. canus and A. pullarius) clustered by species, which is typical for avian MHC genes undergoing concerted evolution. The pattern of MHC copy number variation and modes of evolution observed are associated with the timescale of species divergence. We suggest that future studies should include both MHC class I and II genes and multiple species spanning a range of divergence time to enhance our understanding of the evolution of avian MHC diversity.

A bstract We consider two dimensional superconformal Carrollian theories with boundaries and construct two variants of the Boundary Superconformal Carrollian Algebra (BSCCA), viz. the Homogeneous and the Inhomogeneous, by making appropriate identification of the parent superconformal Carrollian algebras. These new algebras are then recovered by appropriate limits of a single copy of Super Virasoro algebra. We then focus on the theory of null tensionless superstrings and construct, for the first time, an open null superstring. The Homogeneous version of the BSCCA is realised as worldsheet symmetries on this open null superstring.

A major goal of fecal pollution monitoring in the environment is to identify point sources of fecal contamination that may pose potential health risks due to animal- and human-specific pathogens. Ideal source tracking markers should have high host specificity and can be employed for the unambiguous identification of the host/fecal point sources. Conserved signature proteins (CSPs) are a class of unique, phylogenetically coherent indicators that are specific to a given taxon (e.g., genus or species). In this study, we report the identification and characterization of a new CSP, whose gene (designated as CSP-DV) is present in a single copy, and for whom homologs showing a high degree of sequence similarity are found only in genomes of Phocaeicola dorei and Phocaeicola vulgatus, two commensal species commonly found in the human gut and feces. We developed a qPCR method targeting this CSP gene to explore its usefulness as a human source tracking marker. We confirmed that the CSP-DV marker showed an absolute human sensitivity (100%) but some cross-reactivities in chicken, cats, dogs, rabbits, and rodents. In recreational water, the CSP-DV marker gene levels were well correlated with those of HF183, a well-validated human marker that predominantly targets the 16S rRNA gene of P. dorei, suggesting that it can be a new potential source tracking tool for human fecal contamination in specific environmental waters. In summary, our CSP-DV marker targets Phocaeicola clade-specific microbes and can provide an additional approach independent of the 16S rRNA gene to detect human sources of fecal pollution.

Parkinson’s disease (PD) is a complex neurodegenerative disorder with a substantial genetic influence. To better characterize the genetic landscape of PD in South Africa, we conducted the largest genetic screening to date for pathogenic single nucleotide and copy number variations (CNVs) using genotyping array data from 689 PD probands. We identified 16 unique missense variants, confirming 15 with Sanger sequencing, in 47 individuals across seven well-established PD genes, with GBA1 and PRKN being most frequent. Also in known PD genes, 18 variants of unknown significance were found. Additionally, CNV analysis using CNV-Finder revealed seven novel CNVs, five in PRKN and two in SNCA, of which, six were validated with Multiplex Ligation-dependent Probe Amplification. The findings highlight the contribution of both rare variants and structural rearrangements to PD in this underrepresented population. This study underscores the importance of expanding genetic research in African cohorts to improve global understanding of PD etiology.

Cells require highly polymorphic receptors to perform accurate self/non-self recognition. In the amoeba Dictyostelium discoideum, polymorphic TgrB1 and TgrC1 proteins are used to bind sister cells and exclude cheaters, but it remains unknown how cells continually generate their extreme genetic diversity. Here, we created a collection of chromosome-length, whole genome sequences from 10 D. discoideum isolates and sister species to understand the evolution of the large tgr gene family. Our dataset includes AX2-214, a widely used D. discoideum lab strain, as well as complete genomes for two Chlamydia-like endosymbionts harbored within amoebae. We find that tgrB1 and C1 lie in a hypermutational hotspot, with haplotypes that undergo repeated intralocus recombination, duplications, transpositions, and inversions. These structural dynamics are highly localized adjacent to tgrB and C, resulting in the gain and loss of dozens of genes. The tgrBC genes themselves frequently duplicate and recombine, leading to the rapid generation of unique tgrBC repertoires. In the broader tgr gene family, some genes (e.g., tgrN) are single copy and syntenic across all the genomes, whereas others (e.g., tgrA) prolifically duplicate at similar rates to Dictyostelium transposons. Thus, the tgr genes are among the most rapidly evolving families genome-wide. We propose that the intense diversification within the tgrBC locus can help explain how these genes acquire such extreme levels of polymorphism, with parallels to the MHC immune genes in mammals and other allorecognition systems. This collection of amoeba genomes is also a useful resource for future comparative genomics and molecular evolution studies in Amoebozoa.

Innovative multifunctional tag system for protein purification and analytical characterization.

LitR is a blue-green light-sensing transcriptional regulator that uses coenzyme B12 as a chromophore. In this study, we developed a genome-integrative light-inducible expression (iLiEX) system in Streptomyces griseus NBRC 13350, a Gram-positive bacterium that produces streptomycin. The system incorporates LitR, transcriptional amplification module T7 RNA polymerase, and a serine integrase. Using iLiEX, we achieved light-dependent overproduction of catechol-2,3-dioxygenase and β-glucuronidase (GUS) at levels comparable to those from a high-copy plasmid. Notably, GUS activity was 39-fold higher than with the constitutively strong ermE* promoter. The iLiEX system was also functional in S. coelicolor, S. lividans, S. albus J1074, and S. avermitilis. We improved iLiEX in two key ways: by optimizing the ribosome-binding site of T7 RNA polymerase to increase expression, and by introducing the T7 lysozyme gene to reduce leaky transcription. The system’s versatility was improved by shortening the T7 promoter from 89 to 44 bp. For simple visualization on agar plates, light-dependent overexpression of fluorescent proteins, a chromogenic protein, and a brown pigment synthesis enzyme was demonstrated. High-level production of secreted enzymes, including laccase and transglutaminase, was also confirmed. Overall, we developed a single-copy light-inducible overexpression system with broad functionality across multiple Streptomyces species.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-27850-9.