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Developmental profile of striatal preprotachykinin gene expression.

The normal developmental profile of preprotachykinin (PPT) gene expression was determined in rat striatum from embryonic day 20 to adulthood (greater than 45 days of age). At embryonic day 20, the amount of striatal PPT mRNA was approximately 8% of adult levels, and this specific mRNA approached adult levels by postnatal days 12-15. The absolute amount of PPT mRNA, determined by comparison with PPT mRNA synthesized in vitro, ranged from 0.2 pg/micrograms of total RNA at embryonic day 22 to 5-6 pg/micrograms of total RNA in adult striata. In addition, the proportion of the various PPT mRNAs derived from the same primary transcript by alternate splicing was determined in the developing animal. At those ages at which PPT mRNA levels were significantly less than those in the adult, there was a slight (10%) but statistically significant increase in the relative amount of gamma-PPT mRNA with respect to the amount of beta-PPT mRNA. Because these mRNA species encode different combinations of tachykinin peptides, these data suggest that the proportion of substance P versus various neurokinin A-related peptides may be developmentally regulated.

Aging

Whole blood transcriptome profile identifies motor neurone disease RNA biomarker signatures.

Blood-based biomarkers for motor neuron disease are needed for better diagnosis, progression prediction, and clinical trial monitoring. We used whole blood-derived total RNA and performed whole transcriptome analysis to compare the gene expression profiles in (motor neurone disease) MND patients to the control subjects. We compared 42 MND patients to 42 aged and sex-matched healthy controls and described the whole transcriptome profile characteristic for MND. In addition to the formal differential analysis, we performed functional annotation of the genomics data and identified the molecular pathways that are differentially regulated in MND patients. We identified 12,972 genes differentially expressed in the blood of MND patients compared to age and sex-matched controls. Functional genomic annotation identified activation of the pathways related to neurodegeneration, RNA transcription, RNA splicing and extracellular matrix reorganisation. Blood-based whole transcriptomic analysis can reliably differentiate MND patients from controls and can provide useful information for the clinical management of the disease and clinical trials.

Humans

Characterization of multiple transcription initiation sites of the ovine insulin-like growth factor-I gene and expression profiles of three alternatively spliced transcripts.

Alternative splicing of ovine insulin-like growth factor-I (IGF-I) transcripts generates three different mRNAs. Class 1 and class 2 transcripts contain exons 1 and 2 spliced to exon 3, respectively. A novel IGF-I mRNA containing exon W is spliced to exon 3 and has been located upstream of exon 1. No in-frame methionine codon was present in exon W and therefore translation is proposed to initiate at the methionine codon present in exon 3. Using primer extension, transcription initiation sites were found 179, 336, and 368 nucleotides upstream of exon 1 and 86, 96, 131, and approximately 850 nucleotides upstream of exon 2. The locations of these transcription initiation sites are well conserved among mammalian and avian IGF-I genes. Expression of exon 1-, 2-, and W-specific transcripts was examined in brain, heart, kidney, liver, lung, skeletal muscle, and spleen from adult ewes or 75-day fetal lambs using a reverse transcriptase-polymerase chain reaction assay. Exon 1 transcripts were the most abundant and found in all fetal and adult tissues. Exon 2 transcripts were found in all tissues and were generally expressed the highest in adult liver. Exon W transcripts were also found to be expressed in all tissues examined. Thus, the three alternatively spliced ovine IGF-I transcripts were expressed in a variety of fetal and adult tissues.

Amino Acid Sequence

Combining serial analysis of gene expression and array technologies to identify genes differentially expressed in breast cancer.

Several methods have been used recently to determine gene expression profiles of cell populations. Here we demonstrate the strength of combining two approaches, serial analysis of gene expression (SAGE) and DNA arrays, to help elucidate pathways in breast cancer progression by finding genes consistently expressed at different levels in primary breast cancers, metastatic breast cancers, and normal mammary epithelial cells. SAGE profiles of 21PT and 21MT, two well-characterized breast tumor cell lines, were compared with SAGE profiles of normal breast epithelial cells to identify differentially expressed genes. A subset of these candidates was then placed on an array and screened with clinical breast tumor samples to find genes and expressed sequence tags that are consistently expressed at different levels in diseased and normal tissues. In addition to finding the predicted overexpression of known breast cancer markers HER-2/neu and MUC-1, the powerful coupling of SAGE and DNA arrays resulted in the identification of genes and potential pathways not implicated previously in breast cancer. Moreover, these techniques also generated information about the differences and similarities of expression profiles in primary and metastatic breast tumors. Thus, combining SAGE and custom array technology allowed for the rapid identification and validation of the clinical relevance of many genes potentially involved in breast cancer progression. These differentially expressed genes may be useful as tumor markers and prognostic indicators and may be suitable targets for various forms of therapeutic intervention.

Biomarkers, Tumor

Host-Associated Genetic Differentiation in the Face of Ongoing Gene Flow: Ecological Speciation in a Pathogenic Parasite of Freshwater Fish.

Adaptive evolution in response to varying environments, leading to population divergence, is among the most intriguing processes of speciation. However, the extent to which these adaptive processes effectively drive population divergence amidst ongoing gene flow remains controversial. Our study addresses this by analyzing population genetic structure, gene flow, and genomic divergence between lineages of a tapeworm parasite (Ligula intestinalis) isolated from sympatric fish hosts. This parasite, which must overcome host immunological defenses for successful infection, significantly impacts host health. Utilizing genome-wide Single Nucleotide Polymorphisms (SNPs) and transcriptome data, we investigated whether host species impose distinct selection pressures on parasite populations. Genetic clustering analyses revealed clear divergence, with parasites from bream (Abramis brama) forming a distinct genetic cluster separate from those infecting roach (Rutilus rutilus), rudd (Scardinius erythrophthalmus), and bleak (Alburnus alburnus). Demographic modeling indicated isolation with continuous gene flow as the most plausible scenario for this divergence. Selection analyses identified 896 SNPs under selection, displaying low to moderate nucleotide diversity and genetic divergence compared with neutral loci. Transcriptome profiling supported these findings, revealing distinct gene expression profiles between parasite populations. Examination of selected SNPs and differentially expressed genes identified candidate genes linked to immune evasion mechanisms, potentially driving ecological speciation. This research highlights the interplay of host specificity, population demography, and disruptive selection in ecological speciation. By dissecting genomic factors, our study improves the understanding of mechanisms facilitating population divergence despite ongoing gene flow.

Animals

A nucleolar stress gene signature enables quantitative scoring across multi-omics contexts.

The nucleolus is essential for ribosome biogenesis and cellular homeostasis, and its dysfunction can induce nucleolar stress, a process implicated in cancer and other diseases. However, nucleolar stress is commonly inferred from morphological changes or a limited set of functional assays, and quantitative approaches based on gene expression profiles remain lacking. Here, we integrate literature curation with multi-dataset screening to define a nucleolar stress gene signature and develop a nucleolar stress score (NuS) applicable to bulk transcriptomics, single-cell transcriptomics, proteomics, and spatial transcriptomics. Using this framework, we show in colorectal cancer models that oxaliplatin induces nucleolar stress, suppresses nascent rRNA synthesis, and activates p53 signaling, whereas these responses are attenuated in oxaliplatin-resistant cells. Combined with a ribosome biogenesis activity score (RiboSis), NuS captures related but distinct dimensions of nucleolar function and stratifies tumors into functional states associated with clinical outcomes. NuS-based analysis of perturbational transcriptomes further prioritizes compounds with putative nucleolar stress-inducing activity. Collectively, this study provides a quantitative framework for evaluating nucleolar stress and illustrates its applications in disease stratification and drug mechanism discovery.

Cell Nucleolus

Multi-season analysis reveals hundreds of drought-responsive genes in sorghum.

Persistent drought affects global crop production and is becoming more severe in many parts of the world in recent decades. Deciphering how plants respond to drought will facilitate the development of flexible mitigation strategies. Sorghum bicolor L. Moench (sorghum), a major cereal crop and an emerging bioenergy crop, exhibits remarkable resilience to drought. To better understand the molecular traits that underlie sorghum's remarkable drought tolerance, we undertook a large-scale sorghum gene expression profiling effort, totaling nearly 1500 transcriptome profiles, across a 3-year field study with replicated plots in California's Central Valley. This study included time-resolved gene expression data from roots and leaves of two sorghum genotypes, BTx642 and RTx430, with different pre-flowering and post-flowering drought-tolerance adaptations under control and drought conditions. Quantification of genotype-specific drought tolerance effects was enabled by de novo sequencing, assembly, and annotation of both BTx642 and RTx430 genomes. These reference-quality genomes were used to construct a pangene set for characterizing conserved and genotype-specific expression. By integrating time-resolved transcriptomic responses to drought in the field across three consecutive years, we identified a set of 726 drought-responsive genes that responded similarly in all 3 years of our field study. Functional enrichment analysis identified abiotic stress, secondary cell wall-related processes and metabolism as particularly affected under both types of drought stress. We also found that some glyoxylate cycle pathway genes, including malate synthase and isocitrate lyase, are differentially regulated particularly during post-flowering drought stress, implicating this pathway as potentially important for drought responsiveness. This expansive dataset represents a unique resource for sorghum and drought research communities and provides a methodological framework for the integration of multi-faceted time-resolved transcriptomic datasets.

Sorghum

New experimental and computational approaches to the analysis of gene expression.

Public and private EST (Expressed Sequence Tag) programs provide access to a large number of ESTs from a number of plant species, including Arabidopsis, corn, soybean, rice, wheat. In addition to the homology of each EST to genes in GenBank, information about homology to all other ESTs in the data base can be obtained. To estimate expression levels of genes represented in the DuPont EST data base we count the number of times each gene has been seen in different cDNA libraries, from different tissues, developmental stages or induction conditions. This quantitation of message levels is quite accurate for highly expressed messages and, unlike conventional Northern blots, allows comparison of expression levels between different genes. Lists of most highly expresses genes in different libraries can be compiled. Also, if EST data is available for cDNA libraries derived from different developmental stages, gene expression profiles across development can be assembled. We present an example of such a profile for soybean seed development. Gene expression data obtained from Electronic Northern analysis can be confirmed and extended beyond the realm of highly expressed genes by using high density DNA arrays. The ESTs identified as interesting can be arrayed on nylon or glass and probed with total labeled cDNA first strand from the tissue of interest. Two-color fluorescent labeling allows accurate mRNA ratio measurements. We are currently using the DNA array technology to study chemical induction of gene expression and the biosynthesis of oil, carbohydrate and protein in developing seeds.

Blotting, Northern

BISON: bi-clustering of spatial omics data with feature selection.

MOTIVATION: The advent of next-generation sequencing-based spatially resolved transcriptomics (SRT) techniques has reshaped genomic studies by enabling high-throughput gene expression profiling while preserving spatial and morphological context. Understanding gene functions and interactions in different spatial domains is crucial, as it can enhance our comprehension of biological mechanisms, such as cancer-immune interactions and cell differentiation in various regions. It is necessary to cluster tissue regions into distinct spatial domains and identify discriminating genes (DGs) that elucidate the clustering result, referred to as spatial domain-specific DGs. Existing methods for identifying these genes typically rely on a two-stage approach, which can lead to the phenomenon known as double-dipping. RESULTS: To address the challenge, we propose a unified Bayesian latent block model that simultaneously detects a list of DGs contributing to spatial domain identification while clustering these DGs and spatial locations. The efficacy of our proposed method is validated through a series of simulation experiments, and its capability to identify DGs is demonstrated through applications to benchmark SRT datasets. AVAILABILITY AND IMPLEMENTATION: The R/C++ implementation of BISON is available at https://github.com/new-zbc/BISON.

Software

Large-scale analysis of MYB genes in Cucurbitaceae identifies a novel gene regulating plant height.

The MYB transcription factor (TF) family, which is involved in plant growth and development, is large and diverse. Previous studies on MYB family in Cucurbitaceae were mostly based on a single genome or focused on the R2R3 subfamily. Here, we analyzed 91 genomes of 11 Cucurbitaceae species and identified a total of 15 858 MYB genes. According to phylogenetic relationships, these genes were divided into 27 subgroups. The identified MYB genes were further classified into 121 MYB orthologous gene groups (OGGs), including 25 core, 57 softcore, 19 shell and 20 line-specific/cloud groups. Whole-genome duplication was the most common mechanism of MYB genes expansion. In core group, the higher proportions of MYB genes were found to be in the coexpression network constructed by the RNA-seq data. Through the comprehensive analysis including phylogeny and gene expression profile of cucumber MYB genes, as well as genetic variations in 103 cucumber germplasms, we identified a MYB gene CsRAX5, which may be related to cucumber plant height. We used gene editing technology to knockout and overexpress CsRAX5. In the knockout lines, Csrax5, the height was significantly increased compared with wild type (WT), whereas after overexpression the height of CsRAX5-OE plants was significantly decreased compared with WT. These results indicated that MYB gene CsRAX5 negatively regulated cucumber plant height. The large-scale analysis of MYB genes in Cucurbitaceae in this study provides insights for further investigating the evolution and function of MYB genes in Cucurbitaceae crops.

Journal Article

Identification of mitophagy-related biomarkers with immune cell infiltration in psoriasis.

BACKGROUND: Psoriasis is an inflammatory disorder characterized by scaly erythematous plaques and significant comorbidities. Recent studies have suggested that impaired mitophagy, the cellular mechanism for removing dysfunctional mitochondria, may contribute to the pathogenesis of psoriasis. METHODS: In this study, we analyzed bulk RNA sequencing data from 167 healthy individuals and 177 patients with psoriasis obtained from the Gene Expression Omnibus database (GSE30999 and GSE54456). Mitophagy-related genes were isolated using weighted gene co-expression network analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed and protein-protein interaction networks were constructed for the functional enrichment of genes associated with mitophagy. The correlations between genes associated with mitophagy, signaling pathways, and immune cell infiltration were analyzed. The potential diagnostic value of genes associated with mitophagy was evaluated using receiver operating characteristic (ROC) curves, which were validated in imiquimod-induced psoriatic skin lesions in mice. RESULTS: We identified 3,839 differentially expressed genes between healthy individuals and patients with psoriasis, and 23 genes were selected as hub genes showing a high correlation with mitophagy in psoriasis. GO and KEGG analyses revealed that hub and associated genes were significantly correlated with skin functions, such as epidermal development and keratinocyte differentiation. In addition, mitophagy-related genes were negatively associated with pro-inflammatory and pro-proliferation pathways in psoriasis. Among the immune cells, CD4+ T cells were most significantly affected by mitophagy-related genes. ROC analysis demonstrated that mitophagy-related genes, especially ACER1, C1ORF68, CST6, FLG2, GJB3, GJB5, GPRIN2, KRT2, and SPRR4 were potential biomarkers of psoriasis for use in diagnosis or treatment. CONCLUSIONS: Mitophagy-related genes play crucial roles in psoriasis and have potential use as biomarkers, providing insights into disease mechanisms and therapeutic targets. Further research may lead to the development of new strategies for psoriasis management.

Psoriasis

MicroSAGE: a modified procedure for serial analysis of gene expression in limited amounts of tissue.

Serial Analysis of Gene Expression (SAGE) is a powerful expression profiling method, allowing the analysis of the expression of thousands of transcripts simultaneously. A disadvantage of the method, however, is the relatively high amount of input RNA required. Consequently, SAGE cannot be used for the generation of expression profiles when RNA is limited, i.e. in small biological samples such as tissue biopsies or microdissected material. Here we describe a modification of SAGE, named microSAGE, which requires 500- to 5000-fold less starting material. Compared with SAGE, microSAGE is simplified due to incorporation of a 'single-tube' procedure for all steps from RNA isolation to tag release. Furthermore, a limited number of additional PCR cycles are performed. Using microSAGE gene expression profiles can be obtained from minute quantities of tissue such as a single hippocampal punch from a rat brain slice of 325 micrometers thickness, estimated to contain, at most, 10(5) cells. This method opens up a multitude of new possibilities for the application of SAGE, for example the characterization of expression profiles in tissue biopsies, tumor metastases or in other cases where tissue is scarce and the generation of region-specific expression profiles of complex heterogeneous tissues.

Animals

Genetic targets related to aging for the treatment of coronary artery disease.

BACKGROUND: Coronary Artery Disease (CAD) is the most common cardiovascular disease worldwide, threatening human health, quality of life and longevity. Aging is a dominant risk factor for CAD. This study aims to investigate the potential mechanisms of aging-related genes and CAD, and to make molecular drug predictions that will contribute to the diagnosis and treatment. METHODS: We downloaded the gene expression profile of circulating leukocytes in CAD patients (GSE12288) from Gene Expression Omnibus database, obtained differentially expressed aging genes through "limma" package and GenaCards database, and tested their biological functions. Further screening of aging related characteristic genes (ARCGs) using least absolute shrinkage and selection operator and random forest, generating nomogram charts and ROC curves for evaluating diagnostic efficacy. Immune cells were estimated by ssGSEA, and then combine ARCGs with immune cells and clinical indicators based on Pearson correlation analysis. Unsupervised cluster analysis was used to construct molecular clusters based on ARCGs and to assess functional characteristics between clusters. The DSigDB database was employed to explore the potential targeted drugs of ARCGs, and the molecular docking was carried out through Autodock Vina. Finally, single-cell data (GSE159677) of arterial intima was used to further explore the expression of aging signature genes in different cell subpopulations. RESULTS: We identified 8 ARCGs associated with CAD, in which HIF1A and FGFR3 were up while NOX4, TCF7L2, HK3, CDK18, TFAP4, and ITPK1 were down in CAD patients. Based on this, CAD patients can be divided into two molecular clusters, among which cluster A mainly involves functional pathways such as ECM receptor interaction and focal adhesion; cluster B mainly involves functional pathways such as amimo sugar and nucleotide sugar metabolism and pyrimidine metabolism. In addition, the molecular docking results showed that retinoic acid and resveratrol had good binding affinity with targets genes. Further single-cell analysis results showed that NOX4, TCF7L2, ITPK1, and HIF1A were specifically expressed in different types of cells in atherosclerotic tissues. CONCLUSION: Our study identified several ARCGs that may be involved in the pathogenesis and progression of CAD. Further, retinoic acid and resveratrol were potential candidate molecule drugs for inhibiting these targets.

Humans

Meta-Merging the Transcriptomes of Gastric Tumors Redefines the Connections among Molecular and Clinical Subtypes.

INTRODUCTION: The availability of a large number of cancer expression profiles presents an excellent opportunity to re-investigate various biological and clinical questions. While several expression profiles have been established for different cancers, merging them may provide a more powerful platform for extensively extrapolating molecular and clinical features across multiple cohorts. MATERIALS AND METHODS: In this study, five gastric tumor expression profiles from the Gene Expression Omnibus [GEO] and one in-house cohort comprising a total of 1,060 samples were merged. The batch effect was removed using non-parametric ComBat analysis, and the seamless merging of datasets was confirmed through various parameters. RESULTS: Extrapolation of ACRG [Asian Cancer Research Group] and TCGA [The Cancer Genome Atlas] molecular subtypes in the merged cohort of 1,060 gastric tumors revealed nine distinct clusters. Notably, the following patterns were observed: [i] mutual exclusivity between Epithelial to Mesenchymal Transition [EMT] and Microsatellite Instability [MSI] subtypes in 90% of tumors; [ii] overlapping occurrence of EMT and MSI subtypes in the remaining tumors; [iii] overlap between MSI and Epstein-Barr Virus [EBV] subtype tumors; [iv] both commonalities and differences between EMT and Genomically Stable [GS] subtypes; and [v] an association between EBV positivity and PI3K mutation. CONCLUSION: The current study demonstrates that compiling a larger expression profile is valuable for revisiting the molecular features and epidemiology associated with molecular subtypes, thereby aiding in the development of novel diagnostics and targeted therapeutics.

Humans

A profile of differentially expressed genes in primary colorectal cancer using suppression subtractive hybridization.

As a step towards understanding the complex differences between normal cells and cancer cells, we have used suppression subtractive hybridization (SSH) to generate a profile of genes overexpressed in primary colorectal cancer (CRC). From a 35¿ omitted¿000 clone SSH-cDNA repertoire, we have screened 400 random clones by reverse Northern blotting, of which 45 clones were scored as overexpressed in tumor compared to matched normal mucosa. Sequencing showed 37 different genes and of these, 16 genes corresponded to known genes in the public databases. Twelve genes, including Smad5 and Fls353, have previously been shown to be overexpressed in CRC. A series of known genes which have not previously been reported to be overexpressed in cancer were also recovered: Hsc70, PBEF, ribophorin II and Ese-3B. The remaining 21 genes have as yet no functional annotation. These results show that SSH in conjunction with high throughput screening provides a very efficient means to produce a broad profile of genes differentially expressed in cancer. Some of the genes identified may provide novel points of therapeutic intervention.

Adenocarcinoma

Serial analysis of gene expression in HIV-1-infected T cell lines.

The gene expression profile of the HIV-1 infection state was analyzed in the human T cell line MOLT-4. Using the serial analysis of gene expression (SAGE) method, a total of 142¿ omitted¿603 SAGE tags were sequenced and identified, representing 43¿ omitted¿581 unique mRNA species. Comparison of expression patterns revealed that 53 cellular genes were differentially expressed upon HIV-1 infection. Northern blot and RT-PCR analyses confirmed the altered expression of the genes in both MOLT-4 and MT-4 cells. Up-regulated genes were mainly composed of transcription factors and genes related to T cell activation, whereas down-regulated genes were comprised of mitochondrial proteins, actin-related factors and translational factors. These findings indicate that persistent T cell activation, which may accelerate HIV-1 replication, and the disruption of cellular housekeeping genes including those involved in anti-apoptotic systems, may play an important role in HIV-1-induced pathogenesis.

Apoptosis

Comparative Transcriptomic Analyses Identify Candidate Genes for Convergent Reproductive Shifts in a Bimodal Viviparous Amphibian.

Shifts in reproductive mode represent key evolutionary innovations that shape species' life histories and evolutionary trajectories. Species showing bimodal reproductive strategies with multiple independent origins offer a rare opportunity to gain insights into the adaptive processes and mechanisms underlying convergent traits. The fire salamander, Salamandra salamandra, is the only amphibian exhibiting intraspecific variation in reproductive mode across multiple independent reproductive shifts, enabling investigation of the transition between larviparity (females give birth to aquatic larvae) and pueriparity (females give birth to fully developed terrestrial juveniles) within a single species and across different timescales. Pueriparity is an adaptive innovation that skips the aquatic larval stage, allowing individuals to exploit habitats with no available water bodies. The fire salamander is larviparous across most of its range, but pueriparity has evolved independently at least three times: once in the early Pleistocene within S. s. bernardezi in the mountains of northern Spain, and more recently on two land-bridge islands (NW Spain) inhabited by S. s. gallaica. To identify candidate genes associated with these distinct reproductive modes, we compared gene expression profiles of the uterus and oviduct of pregnant females across two independent evolutionary transitions using RNA-sequencing. We detected shared changes in maternal gene expression among pueriparous S. s. bernardezi and S. s. gallaica relative to their larviparous counterparts, in addition to differences unique to each independent evolutionary transition. Functional enrichment analyses indicated that differentially expressed genes were associated with reproductive timing, angiogenesis, and maternal signalling, consistent with the phenotypic differences observed in the uterine environment and embryonic development between the two reproductive modes. This study represents an important first step towards understanding the genomic basis of the evolution of pueriparity in a remarkable bimodal reproductive system, and provides transcriptomic resources and candidate genes for future research into the genomic architecture underlying this poorly understood adaptive trait.

Animals