Many flowering plants attract pollinators by offering a reward of floral nectar. Remarkably, the molecular events involved in the development of nectaries, the organs that produce nectar, as well as the synthesis and secretion of nectar itself, are poorly understood. Indeed, to date, no genes have been shown to directly affect the de novo production or quality of floral nectar. To address this gap in knowledge, the ATH1 Affymetrix GeneChip array was used to systematically investigate the Arabidopsis nectary transcriptome to identify genes and pathways potentially involved in nectar production. In this study, we identified a large number of genes differentially expressed between secretory lateral nectaries and non-secretory median nectary tissues, as well as between mature lateral nectaries (post-anthessis) and immature lateral nectary tissue (pre-anthesis).
Uncovering the Arabidopsis thaliana nectary transcriptome: investigation of differential gene expression in floral nectariferous tissues.
Specimen part
View SamplesMany flowering plants attract pollinators by offering a reward of floral nectar. Remarkably, the molecular events involved in the development of nectaries, the organs that produce nectar, as well as the synthesis and secretion of nectar itself, are poorly understood. Indeed, to date, no genes have been shown to directly affect the de novo production or quality of floral nectar. To address this gap in knowledge, the ATH1 Affymetrix GeneChip array was used to systematically investigate the Arabidopsis nectary transcriptome to identify genes and pathways potentially involved in nectar production. In this study, we identified a large number of genes differentially expressed between secretory lateral nectaries and non-secretory median nectary tissues, as well as between mature lateral nectaries (post-anthessis) and immature lateral nectary tissue (pre-anthesis).
Uncovering the Arabidopsis thaliana nectary transcriptome: investigation of differential gene expression in floral nectariferous tissues.
Specimen part
View SamplesParadoxical cryptococcosis-associated immune reconstitution inflammatory syndrome
Transcriptomic Predictors of Paradoxical Cryptococcosis-Associated Immune Reconstitution Inflammatory Syndrome.
Specimen part
View SamplesAcute lung rejection is a risk factor for chronic rejection, jeopardizing the long-term survival of lung transplant recipients. At present, acute rejection is diagnosed by transbronchial lung biopsies, which are invasive, expensive, and subject to significant sampling error. In this study, we sought to identify groups of genes whose collective expression in BAL cells best classifies acute rejection versus no-rejection. BAL samples were analyzed from 32 unique subjects whose concurrent histology showed acute rejection (n=14) or no rejection (n=18). Global BAL cell gene expression was measured using Affymetrix U133A microarrays. The nearest shrunken centroid method with 10-fold cross validation was used to define the classification model. 250 runs of the algorithm were performed to determine the range of misclassification error and the most influential genes in determining classifiers. The estimated overall misclassification rate was below 20%. Seven transcripts were present in every classifier and 52 transcripts were present in at least 70% of classifiers; these transcripts were notable for involvement with T-cell function, cytotoxic CD8 activity, and granulocyte degranulation. The proportions of both lymphocytes and neutrophils in BAL samples increased with increasing probability of acute rejection; this trend was more pronounced with neutrophils. We conclude that there is a prominent acute rejection-associated signature in BAL cells characterized by increased T-cell, CD8+ cytotoxic cell, and neutrophil gene expression; this is consistent with established mechanistic concepts of the acute rejection response.
Bronchoalveolar lavage cell gene expression in acute lung rejection: development of a diagnostic classifier.
No sample metadata fields
View SamplesBackground
Posttranslationally modified progesterone receptors direct ligand-specific expression of breast cancer stem cell-associated gene programs.
Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
CFTR is a tumor suppressor gene in murine and human intestinal cancer.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
NRASG12V oncogene facilitates self-renewal in a murine model of acute myelogenous leukemia.
Specimen part
View SamplesSoybean is a rich source of protein and oil and a primary feedstock for biodiesel production. Previous research on soybean indicated that protein, oil and yield are controlled quantitatively in soybean seeds. However, genetic mechanisms controlling seed composition and yield in soybean remain unknown. We used Affymetrix Soybean GeneChips to identify genes that are differentially expressed between developing seeds of the Minsoy and Archer soybean varieties, which differ in seed weight, yield, protein content and oil content. Some of the differentially expressed genes identified in this study may play important roles in controlling these traits.
Identification of differentially expressed genes between developing seeds of different soybean cultivars.
Specimen part
View SamplesUntreated HIV-1 infection progresses through acute and asymptomatic stages to AIDS. While each of the three stages has well-known clinical, virologic and immunological characteristics, much less is known of the molecular mechanisms underlying each stage. Here we report lymphatic tissue microarray analyses revealing for the first time stage-specific patterns of gene expression during HIV-1 infection. We show that while there is a common set of key genes with altered expression throughout all stages, each stage has a unique gene-expression signature. The acute stage is most notably characterized by increased expression of hundreds of genes involved in immune activation, innate immune defenses (e.g.MDA-5, TLR-7 and -8, PKR, APOBEC3B, 3F, 3G), adaptive immunity, and in the pro-apoptotic Fas-Fas-L pathway. Yet, quite strikingly, the expression of nearly all acute-stage genes return to baseline levels in the asymptomatic stage, accompanying partial control of infection. In the AIDS stage, decreased expression of numerous genes involved in T cell signaling identifies genes contributing to T cell dysfunction. These common and stage-specific, gene-expression signatures provide new insights into the molecular mechanisms underlying the host response and the slow, natural course of HIV-1 infection.
Microarray analysis of lymphatic tissue reveals stage-specific, gene expression signatures in HIV-1 infection.
Sex, Age, Specimen part, Disease, Disease stage, Race, Subject
View SamplesThe pathways by which oncogenes, such as MLL-AF9, initiate transformation and leukemia in humans and mice are incompletely defined. In a study of target cells and oncogene dosage, we found that Mll-AF9, when under endogenous regulatory control, efficiently transformed LSK (Lin- Sca1+ c-kit+) stem cells while committed granulocyte-monocyte progenitors (GMPs) were transformation-resistant and did not cause leukemia. Mll-AF9 was expressed at higher levels in hematopoietic stem (HSC) than GMP cells. Mll- AF9 gene dosage effects were directly shown in experiments where GMPs were efficiently transformed by the high dosage of Mll-AF9 resulting from retroviral transduction. Mll-AF9 up-regulated expression of 196 genes in both LSK and progenitor cells, but to higher levels in LSKs than in committed myeloid progenitors.
Malignant transformation initiated by Mll-AF9: gene dosage and critical target cells.
No sample metadata fields
View Samples