MOLECULAR GENETICS AND GENOMICS

Genome-wide association study identified QTLs and genes underlying early seedling vigour in aus rice (Oryza sativa L.)
Basha FTM, Sar P, Bhowmick PK, Mahato A, Bisht DS, Iquebal MA, Chakraborty K, Banerjee A, Verma BC, Bhaduri D, Kumar J, Ngangkham U, Saha S, Priyamedha , Mandal NP and Roy S
Early seedling vigour (ESV) is a key trait that enhances early establishment, stress tolerance, and grain yield in rice, especially in direct-seeded rice (DSR) systems. The aus varietal groups is known for its high seedling vigour. The screening of aus diversity panel for ESV traits and subsequent genome-wide association study (GWAS) can lead to the identification of genetic components of ESV. Here, we report the genetic variation in seven ESV traits along with days to 50% flowering and grain yield in a panel of 181 aus accessions evaluated under field conditions. We observed significant variations in the studied traits. The vegetative vigour, scored visually, was significantly correlated with most of the traits, suggesting its impact on overall plant performance. Comparative analysis of aus genetic groups revealed significant variations, and the subpopulation that includes early maturing drought tolerant genotypes was the most vigorous, and thus ideal for donor selection. GWAS using 918, 863 single nucleotide polymorphism (SNP) markers identified 14 significant QTLs, including seven novel ones, linked to vegetative vigour, average growth rate and seedling biomass. Candidate genes like OsPDR1, NCKAP1, and OsSAUR10, involved in jasmonic acid biosynthesis, ABA signaling, and brassinosteroid pathways, were identified to be associated with ESV regulation. This study provides insights into the genetic basis of ESV in aus rice, identifying promising germplasm and genes that could improve seedling vigour and yield in DSR systems. Future research should validate these findings and integrate them into breeding programs for enhanced rice performance in various environments.
Whole-exome sequencing identifies rare recessive variants in azoospermia patients from consanguineous Pakistani families
Uddin I, Zafar I, Xu C, Li W, Khan MI, Wu L and Bao J
Azoospermia, a severe form of male infertility characterized by the complete absence of sperm in the ejaculate, affects about 1% of the male population, with most cases attributed to nonobstructive azoospermia (NOA) caused by gametogenic failure. NOA has various genetic origins, including chromosomal abnormalities, Y chromosome microdeletions, and monogenic mutations. Although whole-exome sequencing (WES) has identified over thirty candidate genes associated with NOA, the genetic causes of most cases have yet to be elucidated. In our study, we selected seven consanguineous families diagnosed with azoospermia from a total of 21 male infertile families recruited from the rural area of Pakistan. Blood samples were collected from both patients and fertile controls for DNA extraction, followed by WES to identify potential causative recessive monogenic variants linked to male infertility. We successfully identified five deleterious variants among five of the seven families, including three missense biallelic substitutions in WWC2, RPL10L, and SOHLH1, a hemizygous deletion in ESX1, and a homozygous deletion in TXNDC2, which have potentially pathogenic relevance to the azoospermia of human male infertility. These novel findings enhance our understanding of the molecular mechanisms underlying the complex etiology of azoospermia, offering valuable insights for genetic counseling and diagnostics and paving the way for future therapeutic approaches.
From cactus to crop: genomic insights of a beneficial and non-pathogenic Curtobacterium flaccumfaciens strain and the evolution of its pathosystem
Ribeiro DF, de Matos JP, Rocha LCM, da Silva AK, de Paula CH, Cordeiro IF, de Carvalho Lemes CG, Sanchez AB, Garcia CCM, Setubal JC, de Souza RF, de Mello Varani A, Almeida NF and Moreira LM
With the advent of advanced sequencing technologies, new insights into the genomes of pathogens, including those in the genus Curtobacterium, have emerged. This research investigates a newly isolated C. flaccumfaciens strain 208 (Cf208) from Arthrocereus glaziovii, and endemic plant from Iron Quadrangle. Previous results show that Cf208 exhibits the potential to remediate soils, facilitating the growth of tomato plants. Furthermore, Cf208 showed no virulence towards bean plants, thus, confounding its phytopathogenic origins. Using a comprehensive comparative genomics approach, we analyzed the Cf208 genome against 34 other Curtobacterium strains, aiming to discern the genomic landmarks associated with its adaptation as an endophyte and its avirulence in bean crops. This revealed a predominant core genome comprising about 2426 genes (68%). Notably, Cf208 possesses a unique plasmid, pCF208-73, which contains 84 unique genes (2.5%). However, unlike the plasmids previously described for pathogenic strains, pCF208-73 does not feature genes associated with virulence induction. In contrast, while several genes traditionally linked to virulence, like pectate lyases and proteases were identified, but the T4P apparatus emerged as new crucial factor for understanding virulence in the Curtobacterium genus. The presence or absence of this apparatus, especially in strains from different clades, may determine their virulence towards leguminous plants. In conclusion, this work highlights the significance of comparative genomics in unraveling the complexities of pathogenicity within the Curtobacterium genus. Our findings suggest that, although the limited genetic variations, specific genes, particularly those linked to the T4P apparatus, play a fundamental role in their interactions with host plants.
High expression of ADAR mediated by OGT promotes chemoresistance in colorectal cancer through the A-to-I editing pathway
Liu T, Ji W, Wang Y, Zhang Y, Hang Q and Qi F
Colorectal cancer (CRC) is a malignant tumor with poor prognosis and adverse therapeutic effect. The study aims to elucidate the contribution of OGT-mediated glycosylation of ADAR to chemoresistance in CRC through its role and regulatory mechanisms. Variations in OGT expression levels and their impact on CRC cell chemoresistance were investigated using gain-of-function and loss-of-function assays. Through a series of molecular biology experiments, we confirmed that ADAR is the downstream target of OGT regulation, emphasizing the role of OGT-mediated glycosylation in stabilizing ADAR. Furthermore, RNA immunoprecipitation (RIP) assays were conducted to examine the effects of ADAR-mediated A-to-I editing on the mRNA stability and translation of genes associated with DNA damage repair. Elevated OGT expression was found to enhance CRC's malignancy and resistance to chemotherapy. OGT's influence leads to the glycosylation of ADAR, thereby increasing its protein levels. ADAR, through its role in A-to-I editing, modulates the mRNA editing of genes implicated in DNA damage repair. This regulation enhances the expression of these genes, improves DNA repair capabilities, and ultimately, fosters chemoresistance in CRC cells. In conclusion, ADAR promotes PARP1 expression under the positive regulation of OGT-mediated O-glycosylation modification to enhance drug resistance in COAD cells. It provides the research basis for overcoming the drug resistance of CRC.
Discovering the role of microRNAs and exosomal microRNAs in chest and pulmonary diseases: a spotlight on chronic obstructive pulmonary disease
Nan F, Liu B and Yao C
Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition and ranks as the fourth leading cause of mortality worldwide. Despite extensive research efforts, a reliable diagnostic or prognostic tool for COPD remains elusive. The identification of novel biomarkers may facilitate improved therapeutic strategies for patients suffering from this debilitating disease. MicroRNAs (miRNAs), which are small non-coding RNA molecules, have emerged as promising candidates for the prediction and diagnosis of COPD. Studies have demonstrated that dysregulation of miRNAs influences critical cellular and molecular pathways, including Notch, Wnt, hypoxia-inducible factor-1α, transforming growth factor, Kras, and Smad, which may contribute to the pathogenesis of COPD. Extracellular vesicles, particularly exosomes, merit further investigation due to their capacity to transport various biomolecules such as mRNAs, miRNAs, and proteins between cells. This intercellular communication can significantly impact the progression and severity of COPD by modulating signaling pathways in recipient cells. A deeper exploration of circulating miRNAs and the content of extracellular vesicles may lead to the discovery of novel diagnostic and prognostic biomarkers, ultimately enhancing the management of COPD. The current review focus on the pathogenic role of miRNAs and their exosomal counterparts in chest and respiratory diseases, centering COPD.
A comprehensive genome-based analysis identifies the anti-cancerous role of the anoikis-related gene ADH1A in modulating the pathogenesis of breast cancer
Chen C, Guo S, Chai W, Yang J, Yang Y, Chen G, Rao H, Ma Y and Bai S
Breast cancer (BC), a widespread and lethal neoplasm, is irrespective of the subtype of BC. Metastasis remains a crucial determinant for unfavorable outcome. The identification of novel diagnostic markers is instrumental in optimizing the treatment regime for BC. The direct correlation between anoikis and the progression/outcome of BC is well established. Nevertheless, the contribution of anoikis-related genes (ARGs) in BC remains obscure at present. We implemented the METABRIC dataset to scrutinize and assess differentially expressed ARGs in BC versus healthy breast tissues. An unsupervised consensus clustering approach for ARGs was employed to classify patients into diverse subtypes. ESTIMATE algorithms were utilized to assess immune infiltrative patterns. Prognostic gene expression patterns were derived from LASSO regression and univariate COX regression analysis. Subsequently, these signatures underwent examination via use of the Kaplan-Meier survival curve. 6 pairs of fresh tissue specimens (tumor and adjacent non-tumor) were employed to assess the expression of 7 ARGs genes via qPCR. Notably, DCN and FOS were not expressed in BC tissue, which had been excluded in our subsequent experiments. Also, among remaining 5 ARGs, solely the expression of ADH1A demonstrated a statistically remarkable disparity between freshly collected cancer tissues and the adjacent ones. ADH1A-overexpressed and ADH1A-sh vectors were transfected into MCF-7 and MCF-7-AR cell lines, respectively. The expression status of FABP4, CALML5, ADH1A, C1orf106, CIDEC, β-catenin, N-cadherin, and Vimentin in the clinical samples were scrutinized using RT-qPCR and western blotting techniques. Migration and invasion through transwell chambers were employed to assess the migratory and invasive potential of the cells. Detailed evaluation of cell proliferation was conducted utilizing a Cell Counting Kit-8 (CCK-8) assay. The apoptotic index of the cells was determined by flow cytometry analysis. An innovative anoikis-associated signature consisting of seven genes, namely ADH1A, DCN, CIEDC, FABP4, FOS, CALML5, and C1orf106, was devised to stratify BC patients into high- and low-risk cohorts. This unique risk assessment model, formulated via the distinctive signature approach, has been validated as an independent prognostic indicator. Additional analysis demonstrated that distinct risk subtypes manifested variances in the tumor microenvironment and drug sensitivities. Suppression of ADH1A enhanced the migratory and invasive capacities and reduced these tumorigenesis-related protein levels, underscoring the prognostic role of ADH1A in the progression of BC. Through our meticulous study, we have elucidated the possible molecular markers and clinical implications of ARGs in BC. Our model, which incorporate seven ARGs, has proven to accurately forecast the survival outcomes of BC patients. Moreover, the thorough molecular study of ADH1A has augmented our comprehension of ARGs in BC and opened a novel avenue for guiding personalized and precise therapeutic interventions for BC patients.
Investigating the genomic and metabolic abilities of PGPR Pseudomonas fluorescens in promoting plant growth and fire blight management
Mankoti M, Pandit NK, Meena SS and Mohanty A
Pseudomonas fluorescens is commonly found in diverse environments and is well known for its metabolic and antagonistic properties. Despite its remarkable attributes, its potential role in promoting plant growth remains unexplored. This study examines these traits across 14 strains residing in diverse rhizosphere environments through pangenome and comparative genome analysis, alongside molecular docking studies against Erwinia amylovora to combat fire blight. Whole genome analysis revealed circular chromosome (6.01-7.07 Mb) with GC content averaging 59.95-63.39%. Predicted genes included 16S rRNA and protein-coding genes ranging from 4435 to 6393 bp and 1527 to 1541 bp, respectively. Pangenome analysis unveiled an open pangenome, shedding light on genetic factors influencing plant growth promotion and biocontrol, including nitrogen fixation, phosphorus solubilization, siderophore production, stress tolerance, flagella biosynthesis, and induced systemic resistance. Furthermore, pyrrolnitrin, phenazine-1-carboxylic acid, pyoluteorin, lokisin, 2,4-diacetylpholoroglucinol and pseudomonic acid were identified. Molecular docking against key proteins of E. amylovora highlighted the high binding affinities of 2,4-diacetylphloroglucinol, pseudomonic acid, and lokisin. These findings underscore the multifaceted role of P. fluorescens in plant growth promotion and biocontrol, with key biomolecules showing promising applications in plant growth and defense against pathogens.
WTAP increases BMP2 expression to promote osteoblast differentiation and inhibit osteoblast senescence via mA methylation of Sp1
Yue B, Zhang W, Li M and Xu L
Pro-differentiation and anti-senescence treatment may be potential strategies for senile osteoporosis therapy. However, the regulatory mechanism underlying osteoblast differentiation and senescence in senile osteoporosis remain to be clarified. In the present study, the preosteoblast cell line MC3T3-E1 was used to induce osteoblast differentiation. The HO was applied to induce senescence. HO treatment significantly inhibited the expression of Wilms tumor 1-associating protein (WTAP), runtrelated transcription factor 2 (Runx2), Osterix and specific protein 1 (Sp1), inhibited the alkaline phosphatase (ALP) activity, upregulated the senescence-associated β-galactosidase (SA-β-Gal), and increased the mRNA levels of p16 and p21. WTAP overexpression significantly reversed the effect of HO, during the osteoblast differentiation of MC3T3-E1 cells. The RIP-qRT-PCR and MeRIP-qRT-PCR assays confirmed that N6-methyladenosine (mA) modification of Sp1 mRNA was significantly decreased by HO treatment, but was increased by WTAP overexpression. The mA modification of Sp1 mRNA significantly increased the stability of Sp1 mRNA. The ChIP-qRT-PCR assay and luciferase reporter gene assay showed that Sp1 could bind to the promoter of BMP2. BMP2 knockdown reversed the effect of Sp1 on osteoblast differentiation and senescence. In conclusion, WTAP increased BMP2 expression to promote osteoblast differentiation and inhibit osteoblast senescence via increasing mA methylation of Sp1 mRNA. This study sheds new light on our understanding of mechanisms underlying osteoblast differentiation and senescence, and provides potential strategies for senile osteoporosis therapy.
Virulome and phylogenomic profiling of a novel Burkholderia pseudomallei strain from an Indian clinical isolate
Varshith MR, Ghosh Dastidar R, Shrilaxmi MS, Bhattacharya R, Jha S, Choudhary S, Varny E, Carvalho RA, John L, Sundaramoorthy V, Smith CM, Damerla RR, Herai RH, Biswas SR, Lal PB, Mukhopadhyay C and Ghosh Dastidar S
Highly pathogenic Burkholderia pseudomallei is the causative agent of melioidosis, a neglected tropical disease endemic in Southeast Asian tropical region. This bacterium encompasses diverse virulence factors which further undergo dynamic gene-expression flux as it transits through distinct environmental niches within the host which may lead to manifestation of differential clinical symptoms. B. pseudomallei, is classified as a Tier 1 select agent in the United States and regarded as a risk group 3 organism in India with the potential to be used as bioweapon. Considering these facts, it is vital to uncover both physiological and genetic heterogeneity of B. pseudomallei, particularly to identify any novel virulence factors that may contribute to pathogenicity. B. pseudomallei strain CM000113 was isolated from a clinical case in India, characterized it for its physiological, biochemical, and prominently genetic traits through WGS. It has a type 2 morphotype with faster doubling time and high biofilm producing capacity as compared to Pseudomonas aeruginosa. The genome size is 7.3 Mbp and it is phylogenetically close to B. pseudomallei strain Mahidol 1106a and Burkholderia mallei Turkey 2. We observed genetic heterogeneity, as key virulence factors that were identified shows sequence dissimilarity with reference strains. Additionally, presence of genomic islands, harbouring two virulence factors, GmhA and GmhB2, associated with pathogenesis indicates possibility of horizontal gene transfer. These results emphasize the need for an extensive study focusing the genome of B. pseudomallei and its associated heterogeneity, to identify molecular biomarkers aiding to develop point-of-care diagnostic kits for early diagnosis of melioidosis.
Pangenome analysis of five representative Tropheryma whipplei strains following multiepitope-based vaccine design via immunoinformatic approaches
Hasan A, Ibrahim M, Alonazi WB, Yu R and Li B
Whipple disease caused by Tropheryma whipplei a gram-positive bacterium is a systemic disorder that impacts not only the gastrointestinal tract but also the vascular system, joints, central nervous system, and cardiovascular system. Due to the lack of an approved vaccine, this study aimed to utilize immunoinformatic approaches to design multiepitope -based vaccine by utilizing the proteomes of five representative T. whipplei strains. The genomes initially comprised a total of 4,844 proteins ranging from 956 to 1012 proteins per strain. We collected 829 nonredundant lists of core proteins, that were shared among all the strains. Following subtractive proteomics, one extracellular protein, WP_033800108.1, a WhiB family transcriptional regulator, was selected for the chimeric-based multiepitope vaccine. Five immunodominant epitopes were retrieved from the WhiB family transcriptional regulator protein, indicating MHC-I and MHC-II with a global population coverage of 70.61%. The strong binding affinity, high solubility, nontoxicity, nonallergenic properties and high antigenicity scores make the selected epitopes more appropriate. Integration of the epitopes into a chimeric vaccine was carried out by applying appropriate adjuvant molecules and linkers, leading to the vaccine construct having enhanced immunogenicity and successfully eliciting both innate and adaptive immune responses. Moreover, the abilityof the vaccine to bind TLR4, a core innate immune receptor, was confirmed. Molecular dynamics simulations have also revealed the promising potential stability of the designed vaccine at 400 ns. In summary, we have designed a potential vaccine construct that has the ability not only to induce targeted immunogenicity for one strain but also for global T. whipplei strains. This study proposes a potential universal vaccine, reducing Whipple's disease risk and laying the groundwork for future research on multi-strain pathogens.
A novel m.5906G > a variant in MT-CO1 causes MELAS/Leigh overlap syndrome
Liu Z, Xie Y, Lou X, Zeng X, Zhang L, Yu M, Wang J, Li J, Shen D, Li H, Zhao S, Zhou Y, Fang H, Lyu J, Yuan Y, Wang Z, Jin L and Fang F
The MELAS/Leigh overlap syndrome manifests with a blend of clinical and radiographic traits from both MELAS and LS. However, the association of MELAS/Leigh overlap syndrome with MT-CO1 gene variants has not been previously reported. In this study, we report a patient diagnosed with MELAS/Leigh overlap syndrome harboring the m.5906G > A variant in MT-CO1, with biochemical evidence supporting the pathogenicity of the variant. The variant m.5906G > A that led to a synonymous variant in the start codon of MT-CO1 was filtered as the candidate disease-causing variant of the patient. Patient-derived fibroblasts were used to generate a series of monoclonal cells carrying different m.5906G > A variant loads for further functional assays. The oxygen consumption rate, ATP production, mitochondrial membrane potential and lactate assay indicated an impairment of cellular bioenergetics due to the m.5906G > A variant. Blue native PAGE analysis revealed that the m.5906G > A variant caused a deficiency in the content of mitochondrial oxidative phosphorylation complexes. Furthermore, molecular biology assays performed for the pathogenesis, mtDNA copy number, mtDNA-encoded subunits, and recovery capacity of mtDNA were all deficient due to the m.5906G > A variant, which might be caused by mtDNA replication deficiency. Overall, our findings demonstrated the pathogenicity of m.5906G > A variant and proposed a potential pathogenic mechanism, thereby expanding the genetic spectrum of MELAS/Leigh overlap syndrome.
Genotyping single nucleotide polymorphisms in homologous regions using multiplex kb level amplicon capture sequencing
Lu M, Li J, Sun X, Zhao D, Zong H, Tang C, Li K, Zhou Y and Xiao J
Single nucleotide polymorphisms (SNPs) in homologous regions play a critical role in the field of genetics. However, genotyping these SNPs is challenging due to the presence of repetitive sequences within genome, which demand specific method. We introduce a new, mid-throughput method that simplifies SNP genotyping in homologous DNA sequences by utilizing a combination of multiplex kb level PCR (PCR size 2.5k-3.5 kb) for capturing targeted regions and multiplex nested PCR library construction for next-generation sequencing (Multi-kb level capture-seq). First of all, we randomly selected 7 SNPs in homologous regions and successfully captured 6-plex kb level amplicons (one of segments contains 2 SNPs, while the remaining segments each have only one SNP) in a single tube. And then, the amplification products were subjected to multiplex nested PCR for library construction and sequenced on Illumina platform. We tested this strategy using 600 amplicons from 100 samples and accurately genotyped 96.8% of target SNPs with a coverage depth of ≥ 15×. For the uniformity within the samples, over 66.7% (4/6) of the amplicons had a coverage depth above 0.2-fold of average sequencing depth. To validate the accuracy of this approach, we performed Ligase detection reaction PCR for genotyping the 100 samples, and found that the genotyping data was 97.71% consistent with our NGS results. In conclusion, we have developed a highly efficient and accurate method for SNP genotyping in homologous regions, which offers researchers a new strategy to explore the complex regions of genome.
Integrated bioinformatics reveals genetic links between visceral obesity and uterine tumors
Samantaray S, Joshi N, Vasa S, Shibu S, Kaloni A, Parekh B and Modi A
Visceral obesity (VO), characterized by excess fat around internal organs, is a recognized risk factor for gynecological tumors, including benign uterine leiomyoma (ULM) and malignant uterine leiomyosarcoma (ULS). Despite this association, the shared molecular mechanisms remain underexplored. This study utilizes an integrated bioinformatics approach to elucidate common molecular pathways and identify potential therapeutic targets linking VO, ULM, and ULS. We analyzed gene expression datasets from the Gene Expression Omnibus (GEO) to identify differentially expressed genes (DEGs) in each condition. We found 101, 145, and 18 DEGs in VO, ULM, and ULS, respectively, with 37 genes overlapping across all three conditions. Functional enrichment analysis revealed that these overlapping DEGs were significantly enriched in pathways related to cell proliferation, immune response, and transcriptional regulation, suggesting shared biological processes. Protein-protein interaction network analysis identified 14 hub genes, of which TOP2A, APOE, and TYMS showed significant differential expression across all three conditions. Drug-gene interaction analysis identified 26 FDA-approved drugs targeting these hub genes, highlighting potential therapeutic opportunities. In conclusion, this study uncovers shared molecular pathways and actionable drug targets across VO, ULM, and ULS. These findings deepen our understanding of disease etiology and offer promising avenues for drug repurposing. Experimental validation is needed to translate these insights into clinical applications and innovative treatments.
A novel strategy to map a locus associated with flowering time in canola (Brassica napus L.)
Long Y, Zheng P, Anderson JV, Horvath DP, Sthapit J, Li X, Rahman M and Chao WS
Flowering time is an important agronomic trait for canola breeders, as it provides growers with options for minimizing exposure to heat stress during flowering and to more effectively utilize soil moisture. Plants have evolved various systems to control seasonal rhythms in reproductive phenology including an internal circadian clock that responds to environmental signals. In this study, we used canola cultivar 'Westar' as a recurrent parent and canola cultivar 'Surpass 400' as the donor parent to generate a chromosome segment substitution line (CSSL) and to map a flowering time locus on chromosome A10 using molecular marker-assisted selection. This CSSL contains an introgressed 4.6 mega-bases (Mb) segment (between 13 and 17.6 Mb) of Surpass 400, which substantially delayed flowering compared with Westar. To map flowering time gene(s) within this locus, eight introgression lines (ILs) were developed carrying a series of different lengths of introgressed chromosome A10 segments using five co-dominant polymorphic markers located at 13.5, 14.0, 14.5, 15.0, 15.5, and 16.0 Mb. Eight ILs were crossed with Westar reciprocally and flowering time of resultant 16 F hybrids and parents were evaluated in a greenhouse (2021 and 2022). Four ILs (IL005, IL017, IL035, and IL013) showed delayed flowering compared to Westar (P < 0.0001), and their reciprocal crosses displayed a phenotype intermediate in flowering time of both homozygote parents. These results indicated that flowering time is partial or incomplete dominance, and the flowering time locus mapped within a 1 Mb region between two co-dominant polymorphic markers at 14.5-15.5 Mb on chromosome A10. The flowering time locus was delineated to be between 14.60 and 15.5 Mb based on genotypic data at the crossover site, and candidate genes within this region are associated with flowering time in canola and/or Arabidopsis. The co-dominant markers identified on chromosome A10 should be useful for marker assisted selection in breeding programs but will need to be validated to other breeding populations or germplasm accessions of canola.
Isolation, characterization, and application of a novel Pseudomonas fluorescens phage vB_PF_Y1-MI in contaminated milk
Xuan G, Liu X, Wang Y, Lin H, Jiang X and Wang J
The food industry has incurred substantial losses from contamination by Pseudomonas fluorescens, emphasizing the critical importance of implementing effective control strategies. Phages are potential sterilizers due to their specific killing abilities and the difficulty bacteria face in developing resistance. However, a significant barrier to their development is the lack of diversity among phage types. In this study, we characterized a novel lytic P. fluorescens phage, named vB_PF_Y1-MI. Phage vB_PF_Y1-MI displayed a latent period of nearly 10 min and a high burst size of 1493 PFU/cell. This phage showed good activity over a wide range of temperature (up to 70 °C) and pH (3-12). The genome of phage vB_PF_Y1-MI spans 93,233 bp with a GC content of 45%. It encompasses 174 open-reading frames and 19 tRNA genes, while no lysogeny or virulence-associated genes were detected. Phylogenetic analysis positions it as a novel unassigned evolutionary lineage within the Caudoviricetes class among related dsDNA phages. Our study provides foundational insights into vB_PF_Y1-MI and emphasizes its potential as an effective biological control agent against P. fluorescens. This research offers crucial theoretical groundwork and technical support for subsequent efforts in preventing and controlling P. fluorescens contamination.
Characterization of hAT DNA transposon superfamily in the genome of Neotropical fish Apareiodon sp
de Oliveira FS, Azambuja M, Schemberger MO, Nascimento VD, Oliveira JIN, Wolf IR, Nogaroto V, Martins C and Vicari MR
DNA transposons are diverse in fish genomes and have been described to generate genomic evolutionary novelties. hAT transposable element data are scarce in Teleostei genomes, making it challenging to conduct comparative genomic studies to understand their neutrality or function. This study aimed to perform a genomic and molecular characterization of hAT copies to assess the diversity of these elements and associate changes in these sequences to genomic and karyotypic novelties in Apareiodon sp. The data revealed that hAT TEs are highly abundant in the Apareiodon sp. genome, with few possibly autonomous copies. Highly conserved sequences with likely functional transposases were observed in nine hAT elements. A great diversity of hAT subgroups was observed, especially from Ac, Charlie, Blackjack, Tip100, hAT6, and hAT5, and a similar wave of hAT genomic invasion was identified in the genome for these six groups of hAT sequences. The data also revealed a distinct number of microsatellites within degenerated hAT copies. hAT sites were demonstrated to be dispersed in the Apareiodon sp. chromosomes and not involved in W chromosome-specific region differentiation. In conclusion, the genomic analysis revealed a great diversity of hAT elements, possible autonomous copies, and differentiation of degenerated transposable elements into tandem sequences.
Full-length transcriptome characterization and analysis of Carrizo Citrange and molecular insights into pathogen defense
Li R, Hu Y, Wang X, Liu C and Huang G
Citrus huanglongbing (HLB) is a major challenge that impacts the flourishing of the citrus industry. Therefore, analyzing the genomic information of HLB-resistant or tolerant citrus resources is crucial for breeding HLB-resistant citrus varieties. The Carrizo citrange, a hybrid of Citrus sinensis and Poncirus trifoliata, plays a pivotal role in citrus cultivation. However, its genetic explorations are difficult due to the absence of a reference genome or full-length transcriptome. In order to enhance our understanding of the genetic information of citrange, we conducted a full-length transcriptomic sequencing of multiple tissues from the Carrizo citrange using the PacBio Sequel II platform. Moreover, we performed gene ontology (GO) annotation, gene functional annotation, simple sequence repeats (SSR) types analysis, as well as identification of lncRNAs, alternative splicing events, and analysis of pathogen defense-related genes. Results showed that a total of 43,452 isoforms were generated, with 43,307 of them being annotated. GO annotation indicated the involvement of these isoforms in various biological processes, cellular components, and molecular functions. The coding sequence length of the isoforms ranged from 1,000 to 4,000 base pairs (bp). Moreover, we have discovered 54 varieties of transcription factors and regulators, along with 16 classifications of genes associated with resistance. Among all types of SSRs, trimer type SSRs were the most abundant. 130 lncRNAs were predicted to be highly reliable in the isoforms of the Carrizo citrange, with alternative splicing events identified, and the most frequent being retained intron. The analysis of gene family expansion and contraction revealed a significant increase in pathogen defense-related genes within the Carrizo citrange. The results of this study will be of great value for future investigations into gene function in citrange and for expanding the genetic pool for breeding citrus varieties resistant or tolerant to HLB.
Rice homolog of Arabidopsis Xylem NAC domain 1 (OsXND1), a NAC transcription factor regulates drought stress responsive root system architecture in indica rice
Swain N, Sahoo RK, Jeughale KP, Sarkar S, Selvaraj S, Parameswaran C, Katara J, Bose LK and Samantaray S
Rice yield is greatly constrained by drought stress. In Arabidopsis, XYLEM NAC DOMAIN 1 (XND1) gene regulates the xylem formation, efficiency of water transport, and the delicate equilibrium between drought tolerance and resistance to pathogens. However, diversity and the role of rice homologs of OsXND1 is not reported so far. This study hypothesized that the rice homolog of OsXND1 also regulates drought stress tolerance through modulation of root architecture. Initially, phylogenetic analysis identified two OsXND1 homologs (Os02g0555300 and Os04g0437000) in rice. Further, 14 haplotypes were identified in the OsXND1 of which Hap1 and Hap3 were major haplotypes. The association analysis of OsXND1 with 16 different traits, including 10 root traits, showed three SNPs (Chr02:20972728-Promoter variant; Chr02:20972791-5' UTR variant, and Chr02:20973745-3' UTR variant) were significantly associated with root area, root surface area, total root length, and convex hull area only under drought stress in indica rice. Besides, the superior haplotype of OsXND1 increased the root area, root surface area, total root length, and convex hull area by 46%, 40%, 38%, and 42%, respectively, under drought stress conditions. Therefore, the identified superior haplotype of OsXND1 can be utilized in haplotype breeding programs for the improvement of drought tolerance in rice.
Unveiling genetic anchors in saccharomyces cerevisiae: QTL mapping identifies IRA2 as a key player in ethanol tolerance and beyond
Tristão LE, de Sousa LIS, de Oliveira Vargas B, José J, Carazzolle MF, Silva EM, Galhardo JP, Pereira GAG and de Mello FDSB
Ethanol stress in Saccharomyces cerevisiae is a well-studied phenomenon, but pinpointing specific genes or polymorphisms governing ethanol tolerance remains a subject of ongoing debate. Naturally found in sugar-rich environments, this yeast has evolved to withstand high ethanol concentrations, primarily produced during fermentation in the presence of suitable oxygen or sugar levels. Originally a defense mechanism against competing microorganisms, yeast-produced ethanol is now a cornerstone of brewing and bioethanol industries, where customized yeasts require high ethanol resistance for economic viability. However, yeast strains exhibit varying degrees of ethanol tolerance, ranging from 8 to 20%, making the genetic architecture of this trait complex and challenging to decipher. In this study, we introduce a novel QTL mapping pipeline to investigate the genetic markers underlying ethanol tolerance in an industrial bioethanol S. cerevisiae strain. By calculating missense mutation frequency in an allele located in a prominent QTL region within a population of 1011 S. cerevisiae strains, we uncovered rare occurrences in gene IRA2. Following molecular validation, we confirmed the significant contribution of this gene to ethanol tolerance, particularly in concentrations exceeding 12% of ethanol. IRA2 pivotal role in stress tolerance due to its participation in the Ras-cAMP pathway was further supported by its involvement in other tolerance responses, including thermotolerance, low pH tolerance, and resistance to acetic acid. Understanding the genetic basis of ethanol stress in S. cerevisiae holds promise for developing robust yeast strains tailored for industrial applications.
Comparative transcriptional analysis between susceptible and resistant populations of Aedes (Stegomyia) aegypti (Linnaeus, 1762) after malathion exposure
de Souza RF, Amaro TR, Palacio-Cortés AM, da Silva MAN, Dionisio JF, Pezenti LF, Lopes TBF, Mantovani MS, Zequi JAC and da Rosa R
Aedes aegypti is an important vector of arboviruses, including dengue, chikungunya and Zika. The application of synthetic insecticides is a frequently used strategy to control this insect. Malathion is an organophosphate insecticide that was widely used in Brazil in the 1980s and 1990s to control the adult form of A. aegypti. In situations where resistance to currently used insecticides is detected, the use of malathion may be resumed as a control measure. Many studies have confirmed resistance to malathion, however, comparative studies of differential gene expression of the entire transcriptome of resistant and susceptible insects are scarce. Therefore, understanding the molecular basis of resistance to this insecticide in this species is extremely important. In this paper, we present the first transcriptomic description of susceptible and resistant strains of A. aegypti challenged with malathion. Guided transcriptome assembly resulted in 39,904 transcripts, where 2133 differentially expressed transcripts were detected, and three were validated by RT-qPCR. Enrichment analysis for these identified transcripts resulted in 13 significant pathways (padj < 0.05), 8 associated with down-regulated and 5 with up-regulated transcripts in treated resistant insects. It was possible to divide the transcripts according to the mechanism of action into three main groups: (i) genes involved in detoxification metabolic pathways; (ii) genes of proteins located in the membrane/extracellular region; and (iii) genes related to DNA integration/function. These results are important in advancing knowledge of genes related to resistance mechanisms in this insect, enabling the development of effective technologies and strategies for managing insecticide resistance.
Differential cellular communication in tumor immune microenvironment during early and advanced stages of lung adenocarcinoma
Shukla M and Sarkar RR
Heterogeneous behavior of each cell type and their cross-talks in tumor immune microenvironment (TIME) refers to tumor immunological heterogeneity that emerges during tumor progression and represents formidable challenges for effective anti-tumor immune response and promotes drug resistance. To comprehensively elucidate the heterogeneous behavior of individual cell types and their interactions across different stages of tumor development at system level, a computational framework was devised that integrates cell specific data from single-cell RNASeq into networks illustrating interactions among signaling and metabolic response genes within and between cells in TIME. This study identified stage specific novel markers which remodel the cross-talks, thereby facilitating immune stimulation. Particularly, multicellular knockout of metabolic gene APOE (Apolipoprotein E in mast cell, myeloid cell and fibroblast) combined with signaling gene CAV1 (Caveolin1 in endothelial and epithelial cells) resulted in the activation of T-cell mediated signaling pathways. Additionally, this knockout also initiated intervention of cytotoxic gene regulations during tumor immune cell interactions at the early stage of Lung Adenocarcinoma (LUAD). Furthermore, a unique interaction motif from multiple cells emerged significant in regulating the overall immune response at the advanced stage of LUAD. Most significantly, FCER1G (Fc Fragment of IgE Receptor Ig) was identified as the common regulator in activating the anti-tumor immune response at both stages. Predicted markers exhibited significant association with patient overall survival in patient specific dataset. This study uncovers the significance of signaling and metabolic interplay within TIME and discovers important targets to enhance anti-tumor immune response at each stage of tumor development.