scholarly journals Sex Steroids Effects on the Molting Process of the Helminth Human ParasiteTrichinella spiralis

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Romel Hernández-Bello ◽  
Ricardo Ramirez-Nieto ◽  
Saé Muñiz-Hernández ◽  
Karen Nava-Castro ◽  
Lenin Pavón ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Steroids ◽  
Parasite Development ◽  
Specific Gene ◽  
Slight Effect ◽  
Crucial Step ◽  
Caveolin 1 ◽  
Molting Process ◽  
Host Parasite

We evaluated thein vitroeffects of estradiol, progesterone, and testosterone on the molting process, which is the initial and crucial step in the development of the muscular larvae (ML or L1) to adult worm. Testosterone had no significative effect on the molting rate of the parasite, however, progesterone decreased the molting rate about a 50% in a concentration- and time-independent pattern, while estradiol had a slight effect (10%). The gene expression of caveolin-1, a specific gene used as a marker of parasite development, showed that progesterone and estradiol downregulated its expression, while protein expression was unaffected. By using flow citometry, a possible protein that is recognized by a commercial antiprogesterone receptor antibody was detected. These findings may have strong implications in the host-parasite coevolution, in the sex-associated susceptibility to this infection and could point out to possibilities to use antihormones to inhibit parasite development.

Serial analysis of gene expression (SAGE) during porcine embryo development

2004 ◽  
Vol 16 (2) ◽  
pp. 87 ◽  
Author(s):  
Le Ann Blomberg ◽  
Kurt A. Zuelke
Keyword(s):  
Gene Expression ◽  
Functional Genomics ◽  
Embryo Development ◽  
Molecular Mechanisms ◽  
Physiological Role ◽  
Transgenic Animals ◽  
Specific Gene ◽  
Research Strategies

Functional genomics provides a powerful means for delving into the molecular mechanisms involved in pre-implantation development of porcine embryos. High rates of embryonic mortality (30%), following either natural mating or artificial insemination, emphasise the need to improve the efficiency of reproduction in the pig. The poor success rate of live offspring from in vitro-manipulated pig embryos also hampers efforts to generate transgenic animals for biotechnology applications. Previous analysis of differential gene expression has demonstrated stage-specific gene expression for in vivo-derived embryos and altered gene expression for in vitro-derived embryos. However, the methods used to date examine relatively few genes simultaneously and, thus, provide an incomplete glimpse of the physiological role of these genes during embryogenesis. The present review will focus on two aspects of applying functional genomics research strategies for analysing the expression of genes during elongation of pig embryos between gestational day (D) 11 and D12. First, we compare and contrast current methodologies that are being used for gene discovery and expression analysis during pig embryo development. Second, we establish a paradigm for applying serial analysis of gene expression as a functional genomics tool to obtain preliminary information essential for discovering the physiological mechanisms by which distinct embryonic phenotypes are derived.

scholarly journals A Dual Role for Oncostatin M Signaling in the Differentiation and Death of Mammary Epithelial Cells in Vivo

2008 ◽  
Vol 22 (12) ◽  
pp. 2677-2688 ◽  
Author(s):  
Paul G. Tiffen ◽  
Nader Omidvar ◽  
Nuria Marquez-Almuina ◽  
Dawn Croston ◽  
Christine J. Watson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Oncostatin M ◽  
Specific Gene ◽  
Mammary Involution

Abstract Recent studies in breast cancer cell lines have shown that oncostatin M (OSM) not only inhibits proliferation but also promotes cell detachment and enhances cell motility. In this study, we have looked at the role of OSM signaling in nontransformed mouse mammary epithelial cells in vitro using the KIM-2 mammary epithelial cell line and in vivo using OSM receptor (OSMR)-deficient mice. OSM and its receptor were up-regulated approximately 2 d after the onset of postlactational mammary regression, in response to leukemia inhibitory factor (LIF)-induced signal transducer and activator of transcription-3 (STAT3). This resulted in sustained STAT3 activity, increased epithelial apoptosis, and enhanced clearance of epithelial structures during the remodeling phase of mammary involution. Concurrently, OSM signaling precipitated the dephosphorylation of STAT5 and repressed expression of the milk protein genes β-casein and whey acidic protein (WAP). Similarly, during pregnancy, OSM signaling suppressed β-casein and WAP gene expression. In vitro, OSM but not LIF persistently down-regulated phosphorylated (p)-STAT5, even in the continued presence of prolactin. OSM also promoted the expression of metalloproteinases MMP3, MMP12, and MMP14, which, in vitro, were responsible for OSM-specific apoptosis. Thus, the sequential activation of IL-6-related cytokines during mammary involution culminates in an OSM-dependent repression of epithelial-specific gene expression and the potentiation of epithelial cell extinction mediated, at least in part, by the reciprocal regulation of p-STAT5 and p-STAT3.

scholarly journals Sex differentiation in grayling (Salmonidae) goes through an all-male stage and is delayed in genetic males who instead grow faster

2017 ◽  
Author(s):  
Diane Maitre ◽  
Oliver M. Selmoni ◽  
Anshu Uppal ◽  
Lucas Marques da Cunha ◽  
Laetitia G. E. Wilkins ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Determination ◽  
Sex Differentiation ◽  
Sex Ratios ◽  
Molecular Genetic ◽  
Specific Gene ◽  
Genetic Sexing ◽  
Experimental Conditions ◽  
Two Samples

AbstractFish can be threatened by distorted sex ratios that arise during sex differentiation. It is therefore important to understand sex determination and differentiation, especially in river-dwelling fish that are often exposed to environmental factors that may interfere with sex differentiation. However, sex differentiation is not sufficiently understood in keystone taxa such as the Thymallinae, one of the three salmonid subfamilies. Here we study a wild grayling (Thymallus thymallus) population that suffers from distorted sex ratios. We found sex determination in the wild and in captivity to be genetic and linked to the sdY locus. We therefore studied sex-specific gene expression in embryos and early larvae that were bred and raised under different experimental conditions, and we studied gonadal morphology in five monthly samples taken after hatching. Significant sex-specific changes in gene expression (affecting about 25,000 genes) started around hatching. Gonads were still undifferentiated three weeks after hatching, but about half of the fish showed immature testes around seven weeks after hatching. Over the next few months, this phenotype was mostly replaced by the “testis-to-ovary” or “ovaries” phenotypes. The gonads of the remaining fish, i.e. approximately half of the fish in each sampling period, remained undifferentiated until six months after fertilization. Genetic sexing of the last two samples revealed that fish with undifferentiated gonads were all males, who, by that time, were on average larger than the genetic females (verified in 8-months old juveniles raised in another experiment). Only 12% of the genetic males showed testicular tissue six months after fertilization. We conclude that sex differentiation starts around hatching, goes through an all-male stage for both sexes (which represents a rare case of “undifferentiated” gonochoristic species that usually go through an all-female stage), and is delayed in males who, instead of developing their gonads, grow faster than females during these juvenile stages.Author contributionMRR and CW initiated the project. DM, OS, AU, LMC, LW, and CW sampled the adult fish, did the experimental in vitro fertilizations, and prepared the embryos for experimental rearing in the laboratory. All further manipulations on the embryos and the larvae were done by DM, OS, AU, LMC, and LW. The RNA-seq data were analyzed by OS, JR, and MRR, the histological analyses were done by DM, supervised by SK, and the molecular genetic sexing was performed by DM, OS, AU, and KBM. DM, OS, and CW performed the remaining statistical analyses and wrote the first version of the manuscript that was then critically revised by all other authors.

scholarly journals In vitro-selected RNA cleaving DNA enzymes from a combinatorial library are potent inhibitors of HIV-1 gene expression

2000 ◽  
Vol 352 (3) ◽  
pp. 667-673 ◽  
Author(s):  
Bandi SRIRAM ◽  
Akhil C. BANERJEA
Keyword(s):  
Gene Expression ◽  
Mammalian Cell ◽  
Specific Gene ◽  
Cleavage Sites ◽  
Dna Enzymes ◽  
Biological Tool ◽  
Catalytic Motif ◽  
Target Rna ◽  
Hiv 1

Selective inactivation of a target gene by antisense mechanisms is an important biological tool to delineate specific functions of the gene product. Approaches mediated by ribozymes and RNA-cleaving DNA enzymes (DNA enzymes) are more attractive because of their ability to catalytically cleave the target RNA. DNA enzymes have recently gained a lot of importance because they are short DNA molecules with simple structures that are expected to be stable to the nucleases present inside a mammalian cell. We have designed a strategy to identify accessible cleavage sites in HIV-1 gag RNA from a pool of random DNA enzymes, and for isolation of DNA enzymes. A pool of random sequences (all 29 nucleotides long) that contained the earlier-identified 10Ő23 catalytic motif were tested for their ability to cleave the target RNA. When the pool of random DNA enzymes was targeted to cleave between any A and U nucleotides, DNA enzyme 1836 was identified. Although several DNA enzymes were identified using a pool of DNA enzymes that was completely randomized with respect to its substrate-binding properties, DNA enzyme-1810 was selected for further characterization. Both DNA enzymes showed target-specific cleavage activities in the presence of Mg2+ only. When introduced into a mammalian cell, they showed interference with HIV-1-specific gene expression. This strategy could be applied for the selection of desired target sites in any target RNA.

scholarly journals Analysis of Plasmodium vivax schizont transcriptomes from field isolates reveals heterogeneity of expression of genes involved in host-parasite interactions

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sasha V. Siegel ◽  
Lia Chappell ◽  
Jessica B. Hostetler ◽  
Chanaki Amaratunga ◽  
Seila Suon ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Ex Vivo ◽  
Culture Method ◽  
Surface Proteins ◽  
Parasite Development ◽  
Field Isolates ◽  
Host Parasite Interactions ◽  
Short Period ◽  
Host Parasite

Abstract Plasmodium vivax gene regulation remains difficult to study due to the lack of a robust in vitro culture method, low parasite densities in peripheral circulation and asynchronous parasite development. We adapted an RNA-seq protocol “DAFT-seq” to sequence the transcriptome of four P. vivax field isolates that were cultured for a short period ex vivo before using a density gradient for schizont enrichment. Transcription was detected from 78% of the PvP01 reference genome, despite being schizont-enriched samples. This extensive data was used to define thousands of 5′ and 3′ untranslated regions, some of which overlapped with neighbouring transcripts, and to improve the gene models of 352 genes, including identifying 20 novel gene transcripts. This dataset has also significantly increased the known amount of heterogeneity between P. vivax schizont transcriptomes from individual patients. The majority of genes found to be differentially expressed between the isolates lack Plasmodium falciparum homologs and are predicted to be involved in host-parasite interactions, with an enrichment in reticulocyte binding proteins, merozoite surface proteins and exported proteins with unknown function. An improved understanding of the diversity within P. vivax transcriptomes will be essential for the prioritisation of novel vaccine targets.

scholarly journals Epigenetic regulation of neural cell differentiation plasticity in the adult mammalian brain

2008 ◽  
Vol 105 (46) ◽  
pp. 18012-18017 ◽  
Author(s):  
Jun Kohyama ◽  
Takuro Kojima ◽  
Eriko Takatsuka ◽  
Toru Yamashita ◽  
Jun Namiki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Epigenetic Modification ◽  
Mammalian Brain ◽  
Cytokine Signaling ◽  
Specific Gene ◽  
Neural Cells ◽  
Specific Gene Expression

Neural stem/progenitor cells (NSCs/NPCs) give rise to neurons, astrocytes, and oligodendrocytes. It has become apparent that intracellular epigenetic modification including DNA methylation, in concert with extracellular cues such as cytokine signaling, is deeply involved in fate specification of NSCs/NPCs by defining cell-type specific gene expression. However, it is still unclear how differentiated neural cells retain their specific attributes by repressing cellular properties characteristic of other lineages. In previous work we have shown that methyl-CpG binding protein transcriptional repressors (MBDs), which are expressed predominantly in neurons in the central nervous system, inhibit astrocyte-specific gene expression by binding to highly methylated regions of their target genes. Here we report that oligodendrocytes, which do not express MBDs, can transdifferentiate into astrocytes both in vitro (cytokine stimulation) and in vivo (ischemic injury) through the activation of the JAK/STAT signaling pathway. These findings suggest that differentiation plasticity in neural cells is regulated by cell-intrinsic epigenetic mechanisms in collaboration with ambient cell-extrinsic cues.

scholarly journals The RNA-binding protein HuR regulates intestinal epithelial restitution by modulating Caveolin-1 gene expression

2020 ◽  
Author(s):  
Shan Cao ◽  
Lan Xiao ◽  
Junyao Wang ◽  
Guodong Chen ◽  
Yulan Liu
Keyword(s):  
Gene Expression ◽  
Posttranscriptional Regulation ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Mrna Levels ◽  
Epithelial Repair ◽  
Caveolin 1 ◽  
Protein Levels ◽  
Ectopic Overexpression

The integrity of the intestinal mucosal barrier protects hosts against pathological conditions. Early mucosal restitution after wounding refers to epithelial cell migration into a defect. The RNA-binding protein HuR plays an important role in the posttranscriptional regulation of gene expression and is involved in many aspects of cellular physiology. In the present study, we investigated the role of HuR in the regulation of cell migration through the posttranscriptional regulation of Caveolin-1 (Cav-1). Online software was used to identify Cav-1 mRNA as a potential target of HuR. The interaction of HuR with Cav-1 mRNA was investigated via ribonucleoprotein immunoprecipitation (RNP IP) assays and biotin pulldown analysis. HuR was found to bind specifically to the Cav-1 3’-UTR rather than the coding region or 5’-UTR. Transfection of cells with siHuR decreased both HuR protein levels and Cav-1 protein levels; conversely, ectopic overexpression of HuR via infection of cells with an adenoviral vector containing HuR cDNA (AdHuR) increased Cav-1 protein levels without disturbing Cav-1 mRNA levels. Thus, HuR enhanced Cav-1 expression in vitro by stimulating Cav-1 translation. Intestinal epithelium–specific HuR knockout in mice decreased Cav-1 protein levels without changing Cav-1 mRNA levels, consistent with the in vitro results. Decreasing the levels of HuR via siHuR transfection inhibited early epithelial repair, but this effect was reversed by ectopic overexpression of GFP-tagged Cav-1. These results indicate that posttranscriptional regulation of Cav-1 gene expression by HuR plays a critical role in the regulation of rapid epithelial repair after wounding.

scholarly journals Gene expression analysis by non-radioactive RNA-RNA in situ hybridization techniques

2004 ◽  
Vol 23 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Danijela Drakulic ◽  
Milena Stevanovic ◽  
Gordana Nikcevic
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Cultured Cells ◽  
Specific Gene ◽  
Rna In Situ Hybridization ◽  
Sox Gene ◽  
Labeled Rna ◽  
Set Up

RNA-RNA in situ hybridization is a reliable method for studying tissue and cell specific gene expression, which enables visualization of labeled antisense RNA probe hybridized to specific mRNA. In this study we employed non-radioactive RNA-RNA in situ hybridization using biotin- or digoxigenin-labeled RNA probes in order to detect SOX gene expression in carcinoma cell lines. By this approach we confirmed results obtained by Northern blot analysis, where the presence of SOX2 mRNA in NT2/D1 and SOX14 mRNA in HepG2 cells has been established. Our aim was to set up RNA-RNA in situ hybridization method in in vitro cultured cells in order to perform further analyses of SOX gene expression on various normal and cancer tissues.

scholarly journals OncogenicGata1causes stage-specific megakaryocyte differentiation delay

2019 ◽  
Author(s):  
Gaëtan Juban ◽  
Nathalie Sakakini ◽  
Hedia Chagraoui ◽  
Qian Cheng ◽  
Kelly Soady ◽  
...  
Keyword(s):  
Gene Expression ◽  
Es Cells ◽  
Erythroid Differentiation ◽  
Detailed Examination ◽  
S Phase ◽  
Myeloproliferative Disorder ◽  
Specific Gene ◽  
Specific Stage

AbstractThe megakaryocyte/erythroid Transient Myeloproliferative Disorder (TMD) in newborns with Down Syndrome (DS) occurs when N-terminal truncating mutations of the hemopoietic transcription factor GATA1, that produce GATA1short protein (GATA1s), are acquired early in development. Prior work has shown that murine GATA1s, by itself, causes a transient yolk sac myeloproliferative disorder. However, it is unclear where in the hemopoietic cellular hierarchy GATA1s exerts its effects to produce this myeloproliferative state. Here, through a detailed examination of hemopoiesis from murine GATA1s ES cells and GATA1s embryos we define defects in erythroid and megakaryocytic differentiation that occur relatively in hemopoiesis. GATA1s causes an arrest late in erythroid differentiationin vivo, and even more profoundly in ES-cell derived cultures, with a marked reduction of Ter-119 cells and reduced erythroid gene expression. In megakaryopoiesis, GATA1s causes a differentiation delay at a specific stage, with accumulation of immature, kit-expressing CD41himegakaryocytic cells. In this specific megakaryocytic compartment, there are increased numbers of GATA1s cells in S-phase of cell cycle and reduced number of apoptotic cells compared to GATA1 cells in the same cell compartment. There is also a delay in maturation of these immature GATA1s megakaryocytic lineage cells compared to GATA1 cells at the same stage of differentiation. Finally, even when GATA1s megakaryocytic cells mature, they mature aberrantly with altered megakaryocyte-specific gene expression and activity of the mature megakaryocyte enzyme, acetylcholinesterase. These studies pinpoint the hemopoietic compartment where GATA1s megakaryocyte myeloproliferation occurs, defining where molecular studies should now be focussed to understand the oncogenic action of GATA1s.Scientific CategoryHaematopoiesis and Stem CellsKey PointsGATA1s-induced stage-specific differentiation delay increases immature megakaryocytesin vivoandin vitro, during development.Differentiation delay is associated with increased numbers of cells in S-phase and reduced apoptosis.

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