Genes最新文献

Background: Starch accumulation contributes substantially to maize grain yield and quality. Starch synthase III (SSIII) is a key component of the starch biosynthetic enzyme complex. However, its regulatory role in starch accumulation in maize endosperm remains incompletely understood.

Methods: The du1-2018 mutant arose spontaneously during a conventional maize breeding program. Phenotypic characterization, storage compound contents, and starch structure were compared between the mutant and wild-type lines. BSA-seq, genetic linkage analysis, and transcriptomic analysis were employed to identify the candidate gene responsible for the mutant phenotype. Transcriptome sequencing was performed on developing kernels to evaluate the genome-wide effects of the du1-2018 mutation.

Results: The du1-2018 mutant exhibited dull, glassy, and mildly shrunken kernels, with decreased starch levels and elevated soluble sugar and protein contents. The du1-2018 mutation disrupted starch accumulation, resulting in smaller, irregularly shaped starch granules and significant changes in starch composition and fine structure. This mutation was identified as a severe loss-of-function allele of the dull1 (du1) gene, evidenced by almost undetectable Du1 transcripts in developing kernels. Notably, transcriptomic analysis revealed that a substantial proportion of differentially expressed genes (DEGs) were involved in amino acid and protein metabolism.

Conclusions: The novel du1 allelic variant, du1-2018, disrupts starch biosynthesis in maize endosperm, leading to reduced starch accumulation, altered starch structure, and transcriptional changes in nitrogen-related metabolic pathways. Our results provide new insights into the regulatory mechanisms underlying SSIII function in starch synthesis and endosperm development, and suggest potential links to carbon/nitrogen balance, with implications for future genetic improvement of maize grain quality.

Background: Autism spectrum disorders (ASDs) are defined as a large spectrum of phenotypes whose basic definition is deficiency in social interactions, particularly during pediatric stages. Through clinical evaluations, it would be challenging to diagnose since the symptoms may be disregarded or controversial. Hence, molecular approaches could be powerful for differential and certain diagnosis. Moreover, considering the possible genetic complexity of the disease, the rates of molecular diagnosis remain insufficient. Nevertheless, the number of newly identified ASD-monogenic inheritance relationships is escalating daily. This underscores the increasing importance of comprehensive molecular tests, such as whole exome sequencing (WES), which encompass all relevant genes. Furthermore, reporting population-specific variants is critical to validate already listed ones and decipher novel ones. In the present study, we aimed to document the disease-related variants in Turkish patients with ASD.

Methods: This study evaluated the WES outcomes of 75 ASD patients with normal results in Fragile X testing, cytogenetic analysis, and molecular karyotyping. All patients were diagnosed with ASD based on the criteria from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5).

Results: The average age of the participants was 8.2 (±5.0) years. A higher percentage of the participants was male (73.3%) compared with female (26.7%). Eighteen patients (24%) had pathogenic or likely pathogenic (LP) variants, while 34 (45.3%) exhibited variants of unknown significance (VUS). In 30.7% of the cases, no clinically relevant variants were found. The MECP2 gene was most frequently affected, followed by EP300 and PTEN. Additionally, four patients carried novel de novo missense variants in the KMT2C, MECP2, PTEN, and TRRAP genes.

Conclusions: Genetic diagnosis of ASD would be useful for confirming the underlying etiologies, devising personalized therapeutic strategies, and offering family counseling. Although WES has been employed in ASD patients for an extended period, the identification of gene and variant spectra across diverse cohorts and the discovery of novel variants continues to hold significant scientific importance.

Background: 22q11.2 deletion syndrome (DiGeorge Syndrome) is a rare disorder that involves a de novo hemizygous microdeletion within the 22q11.2 chromosomal locus. Individuals affected by this condition display a wide array of clinical phenotypes as well as haplotype sequences, which render understanding the genotype-phenotype relationship quite difficult. Additionally, the complex structure of the 22q11.2 low-copy repeats (LCRs), which usually inhibits sequencing efforts, has complicated the study of possible breakpoints that instigate the deletion events. In this study, 22q11.2 deletion syndrome is investigated on a genomic and phenotypic level for the purpose of determining the impact of each deletion type and identifying possible candidate breakpoints. Methods: In the present study, a systematic review combined with a secondary genomic analysis has been executed following PRISMA guidelines using PubMed and Scopus publications in order to estimate its holistic genomic map, genomic functional elements, and key genomic regions such as LCRs. A statistical content analysis of the affected chromosomal regions was also performed. Groups of functional elements with common traits were composed, and their contribution to the deletion events was investigated. Finally, the 22q11.2 repeat regions were screened for palindromic AT-rich repeats. Results: Of the 8202 unique publications studied in this work, only 65 met the inclusion criteria. The estimated genomic map of 22q11.2 deletion syndrome in the secondary genomic analysis revealed 11 distinct microdeletions occurring between eight LCRs, and a new repeat region within the CES region (CESRR), of which the LCR22A-LCR22D deletion was the most frequently reported. Last but not least, the palindromic analyses indicated eight critical groups as candidate breakpoints that potentially form four distinct patterns, and ten palindromic AT-rich repeat (PATRR) regions were identified amongst LCR22A, LCR22B, LCR22D, LCR22F and LCR22H. Conclusions: The study results validate the differentiating clinical contribution between the proximal and the distal segments. Eight novel candidate breakpoints and five new PATRRs were identified that require further study to establish their involvement in 22q11.2 microdeletion events.

Background: Neurodevelopmental disorders (NDDs) are a heterogeneous group of conditions characterized by cognitive, behavioral, and developmental impairments, frequently linked to structural genomic alterations. Copy number variants (CNVs) involving chromosome 16, particularly the short arm 16p, are recognized contributors to neurodevelopmental variability. Despite increasing international evidence, data from Italian clinical cohorts are still limited. Methods: We investigated 1200 patients referred for genetic evaluation due to suspected NDDs, including autism spectrum disorder (ASD), intellectual disability (ID), global developmental delay, and language impairment. All individuals underwent array comparative genomic hybridization (a-CGH) analysis, and identified variants were correlated with detailed clinical, cognitive, and behavioral assessments. The analysis focused on recurrent CNVs at 16p11.2, 16p13.3, and 16p13.11, regions containing dosage-sensitive genes relevant to neurodevelopment. Results: CNVs involving the 16p region were identified in 96 patients (8% of the cohort), encompassing both deletions and duplications. Deletions were mainly associated with developmental delay, language deficits, and ASD-related features, whereas duplications were more frequently linked to behavioral dysregulation, attentional deficits, and variable cognitive impairment. Marked phenotypic variability was observed among individuals carrying similar CNVs, suggesting the contribution of modifying genetic or environmental factors. In a subset of patients, additional CNVs were identified, potentially exacerbating clinical severity, consistent with the two-hit model. Conclusions: This study confirms a strong association between recurrent 16p CNVs and a wide spectrum of neurodevelopmental phenotypes in an Italian clinical cohort. The findings emphasize the diagnostic utility of systematic genomic screening and the importance of an integrated genotype-phenotype approach to improve clinical interpretation, management, and genetic counseling in NDDs.

Background/Objectives: The tumor suppressor gene TP53 is one of the most frequently mutated genes in human cancers, with alterations predominantly affecting its DNA-binding domain (DBD). However, the mutational landscape and functional consequences of TP53 variants remain poorly characterized in African populations. This study aimed to characterize mutations in exons 5-6 of TP53 in oral cavity cancer (OCC), prostate cancer (PC), and breast cancer (BC) in a Senegalese population, and to assess their structural effects, functional consequences, and impact on protein-protein interactions with BCL-2. Methods: Seventy-eight archived tumor DNA samples from Senegalese patients with OCC, PC, and BC were analyzed. Variants were annotated using COSMIC and dbSNP databases. Functional impact was evaluated with PolyPhen-2. Structural stability changes (ΔΔG) were predicted using FoldX, conformational dynamics (ΔΔSvib) were assessed with ENCoM, and effects on the p53-BCL-2 interaction were analyzed using DDMut-PPI. Statistical analyses were also performed. Results: BC exhibited the highest TP53 mutation frequency, whereas OCC showed greater mutational diversity. Exon-level analysis revealed a significant enrichment of exon 6 mutations in BC. Structural analyses indicated that exon 5 mutations across all cancers and mutations in OCC were predominantly destabilizing and associated with loss-of-function effects. In contrast, recurrent exon 6 mutations in PC and BC, particularly V217L and V218M, were predicted to stabilize the p53 structure. Conformational dynamics differences between exons were significant only in PC. All analyzed mutations were predicted to stabilize the p53-BCL-2 interaction. Conclusions: This integrative in silico study identified cancer and exon-specific TP53 mutation patterns in a Senegalese population, highlighting exon 6 as a context-dependent hotspot with potential oncogenic implication in PC and BC. Despite its computational nature, the study provides valuable insights that merit further investigation.

Background: Calcified aortic valve disease (CAVD) is a prevalent valvular disorder in the elderly and a major cause of aortic stenosis. Surgical and transcatheter aortic valve replacement remain the primary treatments for advanced CAVD; however, effective pharmacological therapies to prevent or slow disease progression are lacking. Therefore, there is an urgent need to explore potential novel candidate biomarkers and therapeutic targets.

Methods: In this study, transcriptomic data from multiple independent datasets were integrated to comprehensively characterize the transcriptional profile of CAVD. Feature genes were identified using complementary machine learning approaches, followed by functional pathway enrichment and protein-protein interaction (PPI) network analyses to uncover novel candidate genes associated with CAVD. Single-cell RNA sequencing (sc-RNA-Seq) data were further analyzed using pseudotime trajectory analysis to explore transcriptional dynamics during valve interstitial cells' (VICs) osteogenic progression. Quantitative PCR and Western blot analyses of human calcified aortic valve tissues were used for validation.

Results: A total of 119 CAVD-associated genes were identified, primarily involved in ossification, extracellular matrix organization, and cell-substrate adhesion. Among these, the ossification-associated genes BAMBI, HAND2, and MYOC exhibited potential discriminatory power between CAVD and control samples, with notable downregulation in calcified valves. Pseudotime analysis showed that the expression of these genes gradually decreased along the transcriptional trajectory associated with osteogenic differentiation. In addition, the analysis of relative immune signatures revealed negative correlations between these genes and multiple immune signatures.

Conclusions: This study identifies novel candidate genes underlying CAVD pathogenesis and highlights BAMBI, HAND2, and MYOC as potential biomarkers and therapeutic targets, providing new insights into disease mechanisms and opportunities for novel interventions.

Background: Plant mitochondrial genomes exhibit extreme variation in size and structure while maintaining a conserved set of core protein-coding genes. This combination of structural diversity and functional conservation provides valuable insights into evolutionary processes such as genome expansion, rearrangement, and intracellular DNA transfer. Curcuma longa, an economically and medicinally important species in the genus Curcuma (Zingiberaceae), has not yet been studied in terms of the organization and evolution of its mitochondrial genome. Methods: In this study, we assembled and annotated the mitochondrial and plastid genomes of C. longa using third-generation HiFi sequencing data, systematically analyzing their genomic structure, repetitive sequence content, and features of sequence transfer between nuclear and organellar genomes. Results: The mitochondrial genome of C. longa was assembled as a complex, network-like structure consisting of 12 contigs with a total length of approximately 7.7 Mb, making it one of the largest mitochondrial genomes reported in monocots to date. Comparative analysis revealed significant differences in repeat types, abundance, and length distribution between the two organellar genomes. Additionally, extensive intracellular DNA transfer events were identified among the nuclear, mitochondrial, and plastid genomes. Conclusions: Overall, this study provides the first comprehensive report on the giant mitochondrial genome of C. longa, detailing its structural organization, repeat content, and intergenomic transfers. These findings lay a foundation for understanding mitochondrial genome evolution in Curcuma and offer broader insights into the mechanisms driving extreme mitochondrial genome expansion in angiosperms and monocots specifically.

Background: Skipper butterflies (Hesperiidae) are a morphologically distinctive lineage within Papilionoidea, yet relationships among many groups remain difficult to resolve, and mitochondrial genomic resources remain limited for some tribes, including Celaenorrhinini. Methods: We sequenced and characterized the complete mitochondrial genome of Celaenorrhinus victor using Illumina short-read sequencing. Gene content and organization were annotated, codon-usage patterns were assessed across Celaenorrhinus using relative synonymous codon usage and multiple compositional/selection tests (ENC-GC3s, neutrality, and PR2 analyses), selective constraints were evaluated using Ka/Ks for 13 protein-coding genes, and phylogenetic relationships were inferred with a partitioned maximum-likelihood analysis of 66 complete hesperiid mitogenomes. Results: The circular mitogenome of C. victor is 15,180 bp and contains the typical 37 genes (13 protein-coding genes, 22 tRNAs, and two rRNAs) plus an A + T-rich control region, with an overall A + T content of 79.64%. Gene order and orientation match those of other Celaenorrhinus and hesperiid mitogenomes. All protein-coding genes use standard invertebrate mitochondrial start codons (with cox1 initiating with TTG) and terminate with complete TAA stop codons. Codon usage is strongly biased toward A/U-ending codons and is broadly similar among five sampled Celaenorrhinus mitogenomes; ENC-GC3s, neutrality, and PR2 analyses indicate a predominant influence of A + T-directed mutational pressure with additional effects beyond base composition. Ka/Ks values for all 13 protein-coding genes were <1, consistent with pervasive purifying selection; cox genes were the most conserved, whereas several NADH dehydrogenase subunit genes evolved comparatively faster. The phylogeny recovered monophyletic Celaenorrhinini and a well-supported Celaenorrhinus clade, placing C. victor as sister to Celaenorrhinus consanguineus, while deeper nodes among major hesperiid lineages showed only moderate support in parts of the tree. Conclusions: This study provides a new mitogenomic resource for Celaenorrhinini and a comparative reference for codon usage and selective constraints within Celaenorrhinus, supporting the placement of C. victor within Hesperiidae while highlighting remaining uncertainty at deeper hesperiid divergences.

Background/objectives: piRNAs (PIWI-interacting RNAs) can significantly modify the expression of protein-coding genes by suppressing the translation process. The aim of this work was to computationally evaluate the potential interactions between piRNAs and the mRNA of the Klotho gene, as well as other genes involved in key metabolic pathways related to health and lifespan regulation.

Methods: Bioinformatic analysis was conducted using the MirTarget program, which determines the quantitative characteristics of predicted nucleotide interactions between piRNAs and mRNA targets.

Results: Several piRNAs (piR-44682, piR-1940042, piR-3008660, piR-3215034, piR-6885965, and piR-7980636) were predicted to bind within a single cluster of binding sites on the KL mRNA. In addition, piR-6890096 was predicted to interact with the KL mRNA through full complementarity. The mRNAs of AFF2, BCL2L11, CPT1A, DAZAP1, NDRG3, SKIDA1, WBP4, ZIC5, and ZSWIM6 were predicted to interact with piR-3215034 and piR-6885965, forming clusters of binding sites located in the 5' untranslated region (5'UTR), coding sequence (CDS), and 3' untranslated region (3'UTR). Additionally, piR-576442, piR-1501557, piR-1845735, piR-2069834, and piR-3029987 were predicted to bind only within the 3'UTR of FGF23 mRNA. These results suggest that piRNAs are potential regulators of KL and other genes involved in key metabolic processes.

Conclusions: The findings provide a basis for further experimental validation of predicted piRNA-mRNA interactions and their possible roles in gene regulation.

Background:Astragalus membranaceus is a traditional Chinese medicinal herb with significant pharmacological value. Drought stress adversely affects its biomass accumulation and medicinal quality. Methods: In this study, we performed physiological profiling, transcriptomics, and metabolomics analyses on A. membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao seedlings to elucidate the response mechanisms in both aboveground and root tissues under varying drought stress intensities (Control, CK; Light Drought LD; Moderate Drought MD; Severe Drought SD). Results: Our findings indicate that LD primarily activated antioxidant enzymes, whereas severe stress led to the dominance of osmotic adjustment. Compared with CK, drought treatments resulted in 2987 differentially expressed genes (DEGs; 1674 up-regulated and 1313 down-regulated) and 921 differentially accumulated metabolites (DAMs)-562 in positive ionization mode (224 up, 338 down) and 359 in negative ionization mode (166 up, 193 down). Both gene expression and metabolite accumulation exhibited pronounced stress intensity-dependent patterns, suggesting that A. mongholicus initiates a broad, gene activation-led "active coping" strategy and mobilizes increasingly extensive metabolic pathways as drought intensifies. Conclusions: Integrated transcriptomic and metabolomic analyses revealed a tissue-specific "shoot-root partitioned coordination" mechanism: aboveground tissues activated a glutathione metabolism-centered "antioxidant-osmotic adjustment" defense, while root tissues reconfigured amino acid metabolism to maintain energy supply and signaling. This synergistic coordination represents a core adaptive strategy of A. mongholicus under drought conditions. Our study provides deeper insights into the drought resistance mechanisms of Astragalus and offers valuable references for breeding drought-tolerant varieties of Astragalus and other medicinal plants.