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Transcriptome comparison of winter and spring wheat responding to low temperature.

Freezing tolerance in plants is a complex trait that occurs in many plant species during growth at low, nonfreezing temperatures, a process known as cold acclimation. This process is regulated by a multigenic system expressing broad variation in the degree of freezing tolerance among wheat cultivars. Microarray analysis is a powerful and rapid approach to gene discovery. In species such as wheat, for which large scale mutant screening and transgenic studies are not currently practical, genotype comparison by this methodology represents an essential approach to identifying key genes in the acquisition of freezing tolerance. A microarray was constructed with PCR amplified cDNA inserts from 1184 wheat expressed sequence tags (ESTs) that represent 947 genes. Gene expression during cold acclimation was compared in 2 cultivars with marked differences in freezing tolerance. Transcript levels of more than 300 genes were altered by cold. Among these, 65 genes were regulated differently between the 2 cultivars for at least 1 time point. These include genes that encode potential regulatory proteins and proteins that act in plant metabolism, including protein kinases, putative transcription factors, Ca2+ binding proteins, a Golgi localized protein, an inorganic pyrophosphatase, a cell wall associated hydrolase, and proteins involved in photosynthesis.

Acclimatization↗

Analysis of the floral transcriptome uncovers new regulators of organ determination and gene families related to flower organ differentiation in Gerbera hybrida (Asteraceae).

Development of composite inflorescences in the plant family Asteraceae has features that cannot be studied in the traditional model plants for flower development. In Gerbera hybrida, inflorescences are composed of morphologically different types of flowers tightly packed into a flower head (capitulum). Individual floral organs such as pappus bristles (sepals) are developmentally specialized, stamens are aborted in marginal flowers, petals and anthers are fused structures, and ovaries are located inferior to other floral organs. These specific features have made gerbera a rewarding target of comparative studies. Here we report the analysis of a gerbera EST database containing 16,994 cDNA sequences. Comparison of the sequences with all plant peptide sequences revealed 1656 unique sequences for gerbera not identified elsewhere within the plant kingdom. Based on the EST database, we constructed a cDNA microarray containing 9000 probes and have utilized it in identification of flower-specific genes and abundantly expressed marker genes for flower scape, pappus, stamen, and petal development. Our analysis revealed several regulatory genes with putative functions in flower-organ development. We were also able to associate a number of abundantly and specifically expressed genes with flower-organ differentiation. Gerbera is an outcrossing species, for which genetic approaches to gene discovery are not readily amenable. However, reverse genetics with the help of gene transfer has been very informative. We demonstrate here the usability of the gerbera microarray as a reliable new tool for identifying novel genes related to specific biological questions and for large-scale gene expression analysis.

Asteraceae↗

Transcriptome characterization of human mammary cell lines expressing different levels of ERBB2 by serial analysis of gene expression.

Over-expression of ERBB2, a member of the family of transmembrane receptor tyrosine kinases, occurs in 15-30% of primary breast tumors and is associated with poor prognosis and chemoresistance to a variety of anticancer drugs. In this study, aiming to identify differentially-expressed genes involved in erbB2-mediated transformation of the breast, we generated SAGE libraries from two human mammary cell lines, derived from normal luminal cells, expressing different levels of erbB2. The parental cell line HB4a expresses basal levels and the C5.2 expresses high levels of erbB2. A total of 161,632 tags was generated by sequencing, 81,684 from HB4a cells (30,854 unique tags) and 79,948 from C5.2 cells (30,568 unique tags). The comparison between the HB4a and C5.2 libraries revealed 334 distinct transcripts more expressed in HB4a cells and 328 distinct transcripts more expressed in C5.2 cells. The expression pattern of some of these transcripts was further validated by RT-PCR. The C5.2 cell line, which over-express ERBB2, showed in comparison to HB4a cells a higher percentage of genes involved in transport, RNA processing, apoptosis and protein folding. A higher percentage of the genes more expressed in HB4a cells compared to C5.2 were found to be involved in signal transduction and cytoskeleton organization. The use of SAGE analysis allowed us to identify a significant number of genes implicated in different cellular pathways up- or down-regulated in the presence of ERBB2 over-expression, including genes not previously implicated in breast cancer that could be considered as potential candidate markers for prognosis and therapy.

Breast↗

Molecular analysis of cancer using DNA and protein microarrays.

In conclusion, array-based technologies have emerged that contribute to profiling tissues at the genomic, transcriptomic and proteomic levels. Analytical tools are needed to mine the vast amount of data generated. Ultimately the molecular analysis of cancer at a genome and proteome scale will allow better classification of disease and tailored individualized therapy for individual patients.

Biotechnology↗

Analysis of altered genomic expression profiles in the senescent and diseased myocardium using cDNA microarrays.

Cardiac function deteriorates with aging or disease. Short term, any changes in heart function may be beneficial, but long term the alterations are often detrimental. At a molecular level, functional adaptations involve quantitative and qualitative changes in gene expression. Analysis of all the RNA transcripts present in a cell's population (transcriptome) offers unprecedented opportunities to map these transitions. Microarrays (chips), capable of evaluating thousands of transcripts in one assay, are ideal for transcriptome analyses. Gene expression profiling provides information about the dynamics of total genome expression in response to environmental changes and may point to candidate genes responsible for the cascade of events that result in disease or are a consequence of aging. The aim of this review is to describe how comparisons of cellular transcriptomes by cDNA array based techniques provide information about the dynamics of total gene expression, and how the results can be applied to the study of cardiovascular disease and aging.

Cardiovascular Diseases↗

Genome assembly of Astatotilapia latifasciata uncovers B chromosome-linked chromatin reorganization.

B chromosomes (Bs) are supernumerary genomic elements found in many eukaryotes, yet their full sequence composition, functional potential, and regulatory impact on the host genome remain unclear. Here, we present a chromosome-level genome assembly of the cichlid fish Astatotilapia latifasciata, integrating PacBio long reads, Illumina short reads, and Hi-C chromatin contact maps to resolve both A and B chromosomes. The 0.93 Gb assembly (N50 = 36.2 Mb) includes a 34 Mb B chromosome containing 789 predicted protein-coding genes and a markedly higher density of transposable elements (TEs), especially long terminal repeats (LTR) retrotransposons. Transcriptome profiling revealed that B-linked genes are predominantly transcriptionally repressed relative to their A chromosome paralogs. Hi-C-based chromatin modeling uncovered distinct 3D structural configurations associated with the B chromosome, including fewer topologically associating domains (TADs), reduced loop formation, and altered compartmentalization. These changes are linked to long-range chromatin interactions and genomic rearrangements, suggesting that the B chromosome reshapes the nuclear architecture of the host genome. Our study proposes a potential regulatory role of Bs in genome and provides a genomic resource for investigating chromosome evolution in cichlids.

Animals↗

Transcriptome analysis of the cowpea weevil bruchid: identification of putative proteinases and alpha-amylases associated with food breakdown.

We describe here the first systematic work to discover insect genes involved in food breakdown using a cDNA library enriched for gut-expressed transcripts from Callosobruchus maculatus. A total of 1056 clones were screened for cDNA insert-containing plasmids, and 503 nonredundant open reading frames were discovered. Twenty-three inferred genes potentially involved in digestive processes in cowpea weevil were identified, including proteinases and amylases. The predicted catalytic sites were identified in the inferred cysteine and aspartic acid proteinases, and in alpha-amylases. Transcriptome analysis of the cowpea bruchid will potentially permit gene discovery in other beetles, an insect order of major economic and ecological importance that is poorly represented in genomic databases.

Amino Acid Sequence↗

Construction and usage of a onefold-coverage shotgun DNA microarray to characterize the metabolism of the archaeon Haloferax volcanii.

Haloferax volcanii is a moderately halophilic archaeon that can grow aerobically and anaerobically with a variety of substrates. We undertook a novel approach for the characterization of metabolic adaptations, i.e. transcriptome analysis with a onefold-coverage shotgun DNA microarray. A genomic library was constructed and converted into a polymerase chain reaction (PCR) product library, which was used to print two DNA microarrays, a 960-spot test array used for optimization of microarray analysis and a 2880-spot onefold-coverage array. H. volcanii cultures were shifted from casamino acid-based metabolism to glucose-based metabolism, and the transcriptome changes were analysed with the onefold-coverage array at five time points covering the transition phase and the onset of exponential growth with the new carbon source. About 10% of all genes were found to be more than 2.5-fold regulated at at least one time point. The genes fall into five clusters of kinetically co-regulated genes. For members of all five clusters, the results were verified by Northern blot analyses. The identity of the regulated genes was determined by sequencing. Many co-regulated genes encode proteins of common functions. Expected as well as a variety of unexpected findings allowed predictions about the central metabolism, the transport capacity and the cellular composition of H. volcanii growing on casamino acids and on glucose. The microarray analyses are in accordance with the growth rates and ribosome contents of H. volcanii growing on the two carbon sources. Analysis of the results revealed that onefold-coverage shotgun DNA microarrays are well suited to characterize the regulation of metabolic pathways as well as protein complexes in response to changes in environmental conditions.

Gene Expression Profiling↗

PATTY corrects open chromatin bias for improved bulk and single-cell CUT&Tag profiling.

Precise profiling of epigenomes is essential for better understanding chromatin biology and gene regulation. Cleavage Under Targets & Tagmentation (CUT&Tag) is an efficient epigenomic profiling technique that can be performed on a low number of cells and at the single-cell level. With its growing adoption, CUT&Tag datasets spanning diverse biological systems are rapidly accumulating in the field. CUT&Tag assays use the hyperactive transposase Tn5 for DNA tagmentation. Tn5's preference toward accessible chromatin alters CUT&Tag sequence read distributions in the genome and introduces open chromatin bias that can confound downstream analysis, an issue more substantial in sparse single-cell data. We show that open chromatin bias extensively exists in published CUT&Tag datasets, including those generated with recently optimized high-salt protocols. To address this challenge, we present PATTY (Propensity Analyzer for Tn5 Transposase Yielded bias), a comprehensive computational method that corrects open chromatin bias in CUT&Tag data by leveraging accompanying ATAC-seq. By integrating transcriptomic and epigenomic data using machine learning and integrative modeling, we demonstrate that PATTY enables accurate and robust detection of occupancy sites for both active and repressive histone modifications, including H3K27ac, H3K27me3, and H3K9me3, with experimental validation. We further develop a single-cell CUT&Tag analysis framework built on PATTY and show improved cell clustering when using bias-corrected single-cell CUT&Tag data compared to using uncorrected data. Beyond CUT&Tag, PATTY sets a foundation for further development of bias correction methods for improving data analysis for all Tn5-based high-throughput assays.

Journal Article↗

The Thermotoga maritima phenotype is impacted by syntrophic interaction with Methanococcus jannaschii in hyperthermophilic coculture.

Significant growth phase-dependent differences were noted in the transcriptome of the hyperthermophilic bacterium Thermotoga maritima when it was cocultured with the hyperthermophilic archaeon Methanococcus jannaschii. For the mid-log-to-early-stationary-phase transition of a T. maritima monoculture, 24 genes (1.3% of the genome) were differentially expressed twofold or more. In contrast, methanogenic coculture gave rise to 292 genes differentially expressed in T. maritima at this level (15.5% of the genome) for the same growth phase transition. Interspecies H2 transfer resulted in three- to fivefold-higher T. maritima cell densities than in the monoculture, with concomitant formation of exopolysaccharide (EPS)-based cell aggregates. Differential expression of specific sigma factors and genes related to the ppGpp-dependent stringent response suggests involvement in the transition into stationary phase and aggregate formation. Cell aggregation was growth phase dependent, such that it was most prominent during mid-log phase and decayed as cells entered stationary phase. The reduction in cell aggregation was coincidental with down-regulation of genes encoding EPS-forming glycosyltranferases and up-regulation of genes encoding beta-specific glycosyl hydrolases; the latter were presumably involved in hydrolysis of beta-linked EPS to release cells from aggregates. Detachment of aggregates may facilitate colonization of new locations in natural environments where T. maritima coexists with other organisms. Taken together, these results demonstrate that syntrophic interactions can impact the transcriptome of heterotrophs in methanogenic coculture, and this factor should be considered in examining the microbial ecology in anaerobic environments.

Bacterial Proteins↗

Multiomics approaches to cardiovascular disease: technological innovations and clinical translation.

Cardiovascular diseases (CVDs) remain the leading cause of global morbidity and mortality, reflecting a persistent gap between clinical phenotyping and the molecular mechanisms that govern disease initiation, progression, and interindividual variability. Recent advances in emerging technologies have fundamentally reshaped cardiovascular physiology by enabling high-resolution, cross-layer profiling of the heart and vasculature across genomic, epigenomic, transcriptomic, proteomic, metabolomic, lipidomic, glycomic, and fluxomic layers, increasingly at single-cell and spatial resolution. These approaches reveal CVD as a coordinated, multilayered process driven by dynamic interactions among cell types, regulatory programs, and metabolic states, rather than isolated gene-level defects. In this review, we synthesize how emerging multiomic, computational, and functional genomic technologies are redefining the study of cardiovascular disease across molecular, cellular, and tissue levels. We highlight recent innovations in single-cell and spatial atlases, long-read sequencing, proteomics and metabolomics, integrative data modeling, and functional omics approaches, including genome-scale perturbation screens and single-cell perturbation frameworks. These platforms enable mechanistic dissection of regulatory circuits, distinguish primary disease drivers from secondary adaptations, and directly assess therapeutic reversibility, advancing the field beyond associative biomarker discovery toward mechanism-guided target prioritization. We further discuss key methodological and translational challenges accompanying high-dimensional cardiovascular data, including preanalytical variability, control selection, temporal misalignment across molecular layers, population diversity, and reference bias. By integrating technological innovation with computational rigor and functional validation, this review frames emerging omics-enabled strategies as a unified, physiologically grounded framework for translating molecular insight into clinically meaningful cardiovascular phenotypes and advancing precision cardiovascular medicine.

Humans↗

Safety concerns on the development of novel therapeutic drugs.

Along with recent innovative approaches resulting in the development of new therapies such as small molecular inhibitors, therapeutic antibodies, recombinant proteins and gene therapy, there is increasing need for improved understanding of the basic molecular mechanisms that are exploited by such treatments. Helpful tools in the analysis of drug effects include high-throughput screening techniques such as microarrays, which are used in transcriptomics and pharmacogenomics. Although we are far from using these extensive and costly tests in our daily clinical routine, their application in basic research nevertheless takes us closer to individualized therapeutic strategies, in which the optimal therapeutic regimen is identified for each individual patient.

Drug Design↗

A hormone-dependent tRNA half promotes cell cycle progression via destabilization of p21 mRNA.

tRNA halves are among the most abundant short non-coding RNAs in the cellular transcriptome. Here we report that in androgen receptor-positive LNCaP prostate cancer cells, the hormone-dependent 5'-tRNALysCUU half promoted cell proliferation by facilitating cell cycle progression. Global mRNA profiling upon the 5'-tRNALysCUU half depletion revealed that the mRNA of p21, a negative regulator of the cell cycle, is post-transcriptionally destabilized via a 5'-tRNALysCUU half-driven mechanism. YBX1, identified as a protein interacting with 5'-tRNALysCUU half in the cytosol, was shown to stabilize p21 mRNA. Specific sequences resembling the 5'-tRNALysCUU half, located in the 3'-UTR of p21 mRNA and termed LL588, were identified as the binding site for YBX1 and are required for p21 mRNA stability. In vitro binding assays demonstrated that the 5'-tRNALysCUU half is capable of displacing YBX1 from LL588. Collectively, our findings suggest that the 5'-tRNALysCUU half directly binds to and displaces YBX1 from p21 mRNA, leading to the destabilization of p21 mRNA and the promotion of cell cycle progression in hormone-dependent cancers. Our study illuminates the role of tRNA halves in regulating mRNA stability and suggests that this may be part of broader regulatory networks affecting mRNA levels, orchestrated by various tRNA halves and their interacting proteins.

Humans↗

Proteomic analysis as related to transcriptome data in the lung of chromium(VI)-treated rats.

Assessing the parallelism between transcriptome data and proteome data represents one of the major challenges of post-genomic research. We evaluated the levels of 380 proteins in lung S12 fractions from Sprague-Dawley rats by antibody microarrays. Approximately half of these proteins were detectable under physiological conditions. There was a poor parallelism between mRNA and protein levels for a subset of 84 coinciding or related activities, whose gene expression had previously been investigated by cDNA array. The proportion of detectable proteins was almost twice as high as the proportion of transcriptionally active genes, which reflects the longer half-life of proteins compared to mRNA. Following the local stimulus provided by a short-term and high-dose exposure to sodium dichromate by the intra-tracheal route, 64 additional proteins were detectable in lung S12 fractions, and the correlation between gene expression and protein levels became significant. Sixteen proteins were increased more than twice following chromium(VI) administration. They included ten activities involved in the positive regulation of the cell cycle, three proteins involved in stress response and protein repair, two pro-apoptotic activities, and one protein involved in lipoprotein catabolism. An increase of P53 protein was detected by Western blot in lung nuclear fractions. Post-genomic analyses, highlighting the stimulation of defence mechanisms triggered by DNA damage, contribute to explain the previously reported discrepancy between the ability of chromium(VI) to induce oxidative stress and genotoxic damage in the lung and its failure to induce lung tumors under comparable experimental conditions. The proteome analysis showed a prominent role of apoptosis, counter-balanced by a positive regulation of the cell cycle aimed at replacing lost cells. In conclusion, our results suggest that, under basal conditions, mRNA undergoes a selective inactivation and post-transcriptional regulation resulting in de-coupling of transcriptome data and proteome data. However, this parallelism is re-established when the cell undergoes genotoxic damage.

Animals↗

The cell wall of Paracoccidioides brasiliensis: insights from its transcriptome.

The cell wall of a human pathogenic fungus is in contact with the host, serves as a barrier against host defense mechanisms and harbors most fungal antigens. In addition, cell wall biosynthesis pathways have been recognized as essential to viability and as specific drug targets. Paracoccidioides brasiliensis is a dimorphic fungus that presents mycelium morphology in the free environment and causes infection in a yeast form. The morphogenetic conversion is correlated with changes in the cell wall composition, organization and structure. Based on transcriptome analysis, the enzymes involved in the biosynthesis and remodeling of cell wall polysaccharides, as well as several cell wall-associated molecules of P. brasiliensis, were identified and addressed in further detail.

Cell Wall↗

Gene-expression profiling of White spot syndrome virus in vivo.

White spot syndrome virus, type species of the genus Whispovirus in the family Nimaviridae, is a large, double-stranded DNA (dsDNA) virus that infects crustaceans. The genome of the completely sequenced isolate WSSV-TH encodes 184 putative open reading frames (ORFs), the functions of which are largely unknown. To study the transcription of these ORFs, a DNA microarray was constructed, containing probes corresponding to nearly all putative WSSV-TH ORFs. Transcripts of 79 % of these ORFs could be detected in the gills of WSSV-infected shrimp (Penaeus monodon). Clustering of the transcription profiles of the individual genes during infection showed two major classes of genes: the first class reached maximal expression at 20 h post-infection (p.i.) (putative early) and the other class at 2 days p.i. (putative late). Nearly all major and minor structural virion-protein genes clustered in the latter group. These data provide evidence that, similar to other large, dsDNA viruses, the WSSV genes at large are expressed in a coordinated and cascaded fashion. Furthermore, the transcriptomes of the WSSV isolates WSSV-TH and TH-96-II, which have differential virulence, were compared at 2 days p.i. The TH-96-II genome encodes 10 ORFs that are not present in WSSV-TH, of which at least seven were expressed in P. monodon as well as in crayfish (Astacus leptodactylus), suggesting a functional but not essential role for these genes during infection. Expression levels of most other ORFs shared by both isolates were similar. Evaluation of transcription profiles by using a genome-wide approach provides a better understanding of WSSV transcription regulation and a new tool to study WSSV gene function.

Animals↗

Chronic nitric oxide mediates dual-layer gene regulation through mRNA m6A positional remodeling and parallel transcriptional reprogramming.

Nitric oxide (NO) is a pleiotropic free radical that functions as a master regulator of gene expression, and its sustained production within the tumor microenvironment reshapes the epitranscriptomic state of cancer cells. We previously demonstrated that NO inhibits the m6A mRNA demethylases FTO and ALKBH5 through dinitrosyliron complex formation while leaving the methyltransferase METTL3 intact, a demethylase-specific perturbation that increases global m6A on mRNA. Here, integrating m6A-RIP-seq and RNA-seq from triple-negative breast cancer cells, we show that chronic NO does not produce the uniform hypermethylation anticipated from demethylase inhibition. Instead, it redistributes m6A on mRNA, enriching the 5'UTR and coding sequence while depleting the 3'UTR and departing from the canonical stop-codon and 3'UTR topology. We found that the position of m6A, rather than its intensity or mere presence, shapes the outcome, in part by determining which reader protein is predicted to recognize it. In parallel, NO drives a canonical NF-κB and inflammatory transcriptional program. The transcriptional program is independent of the m6A methylome in both which genes respond and how strongly they respond, ruling out a linear methylome-to-transcriptome cascade; even so, m6A position remains associated with the direction of change among responding transcripts. The 3'UTR is the primary site of m6A loss and shows a suggestive computational link to miRNA-mediated regulation. Sense-antisense coordination reinforces the transcriptional response without bridging the two programs. These findings demonstrate that NO not only increases m6A abundance, but it also rewrites the m6A positional code, establishing spatial reprogramming of the epitranscriptome as a previously unrecognized mode of gene regulation.

RNA Methylation↗

Single-cell sequencing reveals synovial fluid γδ T-cell expansion in equine experimental osteoarthritis.

OBJECTIVE: Define temporal cellular changes following joint injury using single-cell RNA sequencing in experimental equine posttraumatic osteoarthritis (PTOA). METHODS: PTOA was induced in 4 Quarter Horses (3 to 5 years) via carpal osteochondral fragmentation and high-speed treadmill exercise. Synovial fluid (SF) cells and synovium were sampled over 18 weeks (November 2023 to April 2024). Single-cell suspensions were processed (10x Genomics Chromium iX), then aligned to the equine genome (Cell Ranger). Downstream analysis was completed in the R Seurat package. Differential gene expression (log2[fold change] > 1; P < .05) and differential abundance analyses were performed (P < .1). RESULTS: Cartilage injury had a modest impact on gene expression changes and cell abundance shifts in SF. Integrated analysis of 90,323 SF cells across 4 time points revealed 9 distinct cell types, primarily T cells (73 &#xb1; 19%) followed by myeloid cells (20 &#xb1; 13%). Subcluster analysis of T cells revealed 9 transcriptomically distinct subtypes (3 CD8, 2 CD4, 3 &#x3b3;&#x3b4;, and 1 cycling). Differential abundance analyses of temporal changes identified increased &#x3b3;&#x3b4; T and decreased CD4+ T-cell subsets in joints over time. Expanded populations of IL-23 receptor-positive &#x3b3;&#x3b4; T cells exhibited increased T-helper 17 signatures. CONCLUSIONS: IL-23 receptor-positive &#x3b3;&#x3b4; T-cell expansion, associated with joint inflammation, occurred in PTOA. Limitations include small sample size and individual heterogeneity; further investigation over extended timeframe is necessary to confirm whether later stages of the experimental model reflect natural chronic OA. CLINICAL RELEVANCE: Cellular immunotherapy targeting &#x3b3;&#x3b4; T cells and IL-23/IL-17 blockade may warrant investigation to mitigate equine OA progression.

equine↗