scholarly journals Retrotransposon expression as a defining event of genome reprograming in fertilized and cloned bovine embryos

Reproduction ◽  
2009 ◽  
Vol 138 (2) ◽  
pp. 289-299 ◽  
Author(s):  
L C Bui ◽  
A V Evsikov ◽  
D R Khan ◽  
C Archilla ◽  
N Peynot ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Ribosomal Proteins ◽  
Gene Expression Pattern ◽  
Cdna Array ◽  
Ltr Retrotransposons ◽  
Bovine Embryos ◽  
Genes Encoding ◽  
Low Efficiency ◽  
Cloned Bovine

Genome reprograming is the ability of a nucleus to modify its epigenetic characteristics and gene expression pattern when placed in a new environment. Low efficiency of mammalian cloning is attributed to the incomplete and aberrant nature of genome reprograming after somatic cell nuclear transfer (SCNT) in oocytes. To date, the aspects of genome reprograming critical for full-term development after SCNT remain poorly understood. To identify the key elements of this process, changes in gene expression during maternal-to-embryonic transition in normal bovine embryos and changes in gene expression between donor cells and SCNT embryos were compared using a new cDNA array dedicated to embryonic genome transcriptional activation in the bovine. Three groups of transcripts were mostly affected during somatic reprograming: endogenous terminal repeat (LTR) retrotransposons and mitochondrial transcripts were up-regulated, while genes encoding ribosomal proteins were downregulated. These unexpected data demonstrate specific categories of transcripts most sensitive to somatic reprograming and likely affecting viability of SCNT embryos. Importantly, massive transcriptional activation of LTR retrotransposons resulted in similar levels of their transcripts in SCNT and fertilized embryos. Taken together, these results open a new avenue in the quest to understand nuclear reprograming driven by oocyte cytoplasm.

Differential gene expression profile in breast cancer-derived stromal fibroblasts

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 21075-21075
Author(s):  
C. F. Singer ◽  
D. Gschwantler-Kaulich ◽  
A. Fink-Retter ◽  
G. Hudelist ◽  
C. Haas ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Mrna Expression ◽  
Differential Gene Expression ◽  
Gene Expression Pattern ◽  
Cdna Array ◽  
Tumor Stroma ◽  
Normal Breast ◽  
Stromal Fibroblasts ◽  
Differential Gene

21075 Background: Breast cancer is chatacterized by malignant transformation of epithelial cells, but stromal cells also play an important role in tumorigenesis. While tumoral fibroblasts display unique phenotypical properties, it is unclear whether they also represent are a specific subpopulation. Materials and Methods: Stromal fibroblasts deriving from malignant tissue of 10 women with invasive breast cancer, and from normal breast tissue of 10 women with benign breast disorders, were subjected to differential complementary DNA Microarray Analysis by using a 2400 gene cDNA array. Gene expression results were validated by real-time PCR and by immunohistochemistry. Results: In a cDNA Array that allows to analyze the differential gene expression of more than 2400 genes, the mRNA expression of 135 genes were increased more than 2 fold in fibroblasts from malignant breast tumors. The majority of these genes encode tumor-promoting cytokines, transcription factors and cell-matrix associated proteins. The mRNA expression of 110 genes decreased to less than 0.5 fold. The remaining 2155 genes were not significantly altered. Immunohistochemistry for selected proteins performed on biopsies from breast cancer and normal breast tissues confirmed the clinical relevance of our findings. Conclusion: Breast cancer-derived stromal fibroblasts show a distinctive gene expression pattern that differentiates them from normal breast stroma. Our observation of increased expression of tumor promotion-associated genes even in the absence of adjacent malignant epithelium suggests that tumor stroma is comprised of a fibroblastic subpopulation that provides for a microenvironment which supports tumor growth and invasion. No significant financial relationships to disclose.

Establishment of tolerance to commensal bacteria requires a complex microbiota and is accompanied by decreased intestinal chemokine expression

2012 ◽  
Vol 302 (1) ◽  
pp. G55-G65 ◽  
Author(s):  
L. N. Fink ◽  
S. B. Metzdorff ◽  
L. H. Zeuthen ◽  
C. Nellemann ◽  
M. B. Kristensen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lymph Nodes ◽  
Ex Vivo ◽  
Gene Expression Pattern ◽  
Mesenteric Lymph Nodes ◽  
Microbial Detection ◽  
E Coli ◽  
Germ Free ◽  
Expression Of Genes ◽  
Genes Encoding

Intricate regulation of tolerance to the intestinal commensal microbiota acquired at birth is critical. We hypothesized that epithelial cell tolerance toward early gram-positive and gram-negative colonizing bacteria is established immediately after birth, as has previously been shown for endotoxin. Gene expression in the intestine of mouse pups born to dams that were either colonized with a conventional microbiota or monocolonized ( Lactobacillus acidophilus or Eschericia coli ) or germ free was examined on day 1 and day 6 after birth. Intestinal epithelial cells from all groups of pups were stimulated ex vivo with L. acidophilus and E. coli to assess tolerance establishment. Intestine from pups exposed to a conventional microbiota displayed lower expression of Ccl2, Ccl3, Cxcl1, Cxcl2, and Tslp than germ-free mice, whereas genes encoding proteins in Toll-like receptor signaling pathways and cytokines were upregulated. When comparing pups on day 1 and day 6 after birth, a specific change in gene expression pattern was evident in all groups of mice. Tolerance to ex vivo stimulation with E. coli was only established in conventional animals. Colonization of the intestine was reflected in the spleen displaying downregulation of Cxcl2 compared with germ-free animals on day 1 after birth. Colonization reduced the expression of genes involved in antigen presentation in the intestine-draining mesenteric lymph nodes, but not in the popliteal lymph nodes, as evidenced by gene expression on day 23 after birth. We propose that microbial detection systems in the intestine are upregulated by colonization with a diverse microbiota, whereas expression of proinflammatory chemokines is reduced to avoid excess recruitment of immune cells to the maturing intestine.

scholarly journals Global Gene Expression Responses to Cadmium Toxicity in Escherichia coli

2005 ◽  
Vol 187 (9) ◽  
pp. 3259-3266 ◽  
Author(s):  
Anyou Wang ◽  
David E. Crowley
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Cadmium Toxicity ◽  
Gene Expression Profiles ◽  
Global Gene Expression ◽  
Temporal Gene Expression ◽  
Genes Encoding

ABSTRACT Genome-wide analysis of temporal gene expression profiles in Escherichia coli following exposure to cadmium revealed a shift to anaerobic metabolism and induction of several stress response systems. Disruption in the transcription of genes encoding ribosomal proteins and zinc-binding proteins may partially explain the molecular mechanisms of cadmium toxicity.

Gene expression in the in vitro-produced preimplantation bovine embryos

Zygote ◽  
2007 ◽  
Vol 15 (4) ◽  
pp. 355-367 ◽  
Author(s):  
H. Badr ◽  
G. Bongioni ◽  
A.S.S. Abdoon ◽  
O. Kandil ◽  
R. Puglisi
Keyword(s):  
Gene Expression ◽  
Expression Pattern ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Gene Expression Pattern ◽  
Bovine Embryos ◽  
Embryonic Genome ◽  
Altered Gene ◽  
Genome Activation

SummaryRecent studies have demonstrated the relevance of a gene expression profile as a clinically important key feature determining embryo quality during the in vitro preimplantation period. Although the oocyte origin can play a crucial role in blastocyst yield, the postfertilization culture period has a profound effect in determining the blastocyst quality with particular regard to the relative abundance of many developmentally and clinically important candidate genes. During the preimplantation period, the embryo undergoes several morphogenetic developmental events including oocyte maturation, minor and major forms of embryonic genome activation and transition of transcription from maternal to embryonic control. The effect of an altered gene expression pattern on the in vitro-produced bovine embryos, particularly when cultured under suboptimal conditions, was reflected by the occurrence of clinically important phenomena like apoptosis and the large offspring syndrome. This review attempts to focus on the morphogenetic embryo development and gene expression profile in the in vitro-produced bovine embryos, with special emphasis on the different parameters that may alter gene expression pattern during the critical period of in vitro culture. The effect of the in vitro system, as reflected by some clinically important phenomena like apoptosis, is also discussed.

scholarly journals 82 EFFECT OF HIGH FETAL CALF SERUM CONCENTRATION IN THE GENE EXPRESSION PATTERN OF IN VITRO PRODUCED BOVINE EMBRYOS

2014 ◽  
Vol 26 (1) ◽  
pp. 155
Author(s):  
M. J. Sudano ◽  
D. M. Paschoal ◽  
E. S. Caixeta ◽  
R. R. Maziero ◽  
M. D. Guastali ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Lipid Metabolism ◽  
Expression Pattern ◽  
Expression Profiles ◽  
Rna Extraction ◽  
Gene Expression Pattern ◽  
Differentially Expressed ◽  
Bovine Embryos

Even though FCS provides energy substrates, amino acids, vitamins, growth factors, and heavy-metal chelators, its supplementation has been associated with several embryo abnormalities such as mitochondrial degeneration, metabolic deviations, excessive lipid accumulation, and decreased embryo survival after cryopreservation. The aim of the present study was to evaluate the effect of high FCS concentration in the gene expression pattern of in vitro-produced bovine embryos. Slaughterhouse ovaries were used to obtain oocytes (N = 360), which were matured and fertilized in vitro (Day 0). Presumptive zygotes were divided in 2 culture media: with low (SOFaa with 0.5% BSA and 2.5% FCS) or high (SOFaa with 0.5% BSA and 10% FCS) FCS concentration. Cleavage was evaluated on Day 3. Embryo development was evaluated after 7 days under standard culture conditions (at 38.5°C in atmosphere of 5% O2, 5% CO2, and 90% N2). The produced blastocysts were placed in PBS solution and washed five times. A single blastocyst was frozen in a minimal volume of PBS and stored at –80°C until RNA extraction. Total RNA extraction was performed using the PicoPure RNA isolation Kit (Applied Biosystems®, Foster City, CA, USA). Extracted RNA was evaluated through 2100-Bioanalyzer (Agilent Technologies®, Palo Alto, CA, USA) and DNAse treated (Qiagen®, Valencia, CA, USA). RiboAmp RNA Amplification Kit (Applied Biosystems®) was used to amplify the RNA (T7 RNA polymerase-catalysed amplification reaction). The aRNA output was evaluated through NanoDrop ND-1000 (NanoDrop Technologies®, Wilmington, DE, USA). A biotin-labelled cRNA and fragmented cRNA were obtained through 3′IVT Express Kit (Affymetrix®, Santa Clara, CA, USA) to perform the hybridization (N = 3 per group) using GeneChip Bovine Genome Array (Affymetrix®). Following hybridization, probe arrays were washed, stained, and scanned. Microarray data analysis was performed in the software FlexArray 1.6.1.1. Genes with a fold change of at least 1.5 and a probability of P < 0.05 were considered differentially expressed. The data from in vitro embryo production were analysed through the PROC GLM (SAS Institute Inc., Cary, NC, USA). Cleavage rate (81.4 ± 1.5 and 85.5 ± 1.4) and blastocyst production (41.8 ± 2.4 and 47.2 ± 2.8) were not different (P > 0.05) between low and high FCS concentrations, respectively. A total of 40 genes were differentially expressed between low and high FCS concentration. A total of 28 genes were annotated, with 37 genes up-regulated and 3 genes down-regulated by high FCS concentration. The associated network functions of gene expression, RNA damage and repair, and post-transcriptional modification; and cell-to-cell signalling and interaction were generated by Ingenuity Pathway Analysis® (Redwood City, CA, USA). Differentially expressed genes involved in carbohydrate metabolism (GAPVD1, MGAT4A), lipid metabolism (ELOVL5), cellular assembly and organisation (EZR, LRP2), and cell death and survival (DRT8) were identified. In conclusion, high FCS supplementation was associated with different expression profiles of genes regulating carbohydrate and lipid metabolism, cellular assembly and organisation, and cell death and survival. The authors acknowledge support from FAPESP and LNBio-CNPEM.

Patterns of Resistance and Incomplete Response to Docetaxel by Gene Expression Profiling in Breast Cancer Patients

2005 ◽  
Vol 23 (6) ◽  
pp. 1169-1177 ◽  
Author(s):  
Jenny C. Chang ◽  
Eric C. Wooten ◽  
Anna Tsimelzon ◽  
Susan G. Hilsenbeck ◽  
M. Carolina Gutierrez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Expression Pattern ◽  
Gene Expression Pattern ◽  
Cdna Array ◽  
Residual Tumor ◽  
Breast Cancer Patients ◽  
Risk Of Death ◽  
Incomplete Response ◽  
Docetaxel Treatment

Purpose Chemotherapy for operable breast cancer decreases the risk of death. Docetaxel is one of the most active agents in breast cancer, but resistance or incomplete response is frequent. Patients and Methods Core biopsies from 24 patients were obtained before treatment with neoadjuvant docetaxel (four cycles, 100 mg/m2 every 3 weeks), and response was assessed after chemotherapy. After 3 months of neoadjuvant chemotherapy, surgical specimens (n = 13) were obtained, and laser capture microdissection (LCM; n = 8) was performed to enrich for tumor cells. From each core, surgical, and LCM specimen, sufficient total RNA (3 to 6 μg) was extracted for cDNA array analysis using the Affymetrix HgU95-Av2 GeneChip (Affymetrix, Santa Clara, CA). Results From the initial core biopsies, differential patterns of expression of 92 genes correlated with docetaxel response (P = .001). However, the molecular patterns of the residual cancers after 3 months of docetaxel treatment were strikingly similar, independent of initial sensitivity or resistance. This relative genetic homogeneity after treatment was observed in both LCM and non-LCM surgical specimens. The residual tumor after treatment in tumors that were initially sensitive indicates selection of a residual and resistant subpopulation of cells. The gene expression pattern was populated by genes involved in cell cycle arrest at G2M (eg, mitotic cyclins and cdc2) and survival pathways involving the mammalian target of rapamycin. Conclusion A specific and consistent gene expression pattern was found in residual tumors after docetaxel treatment. These profiles provide therapeutic targets that could lead to improved treatment.

Regulation of heat-inducible HSPA1A gene expression during maternal-to-embryo transition and in response to heat in in vitro-produced bovine embryos

2017 ◽  
Vol 29 (9) ◽  
pp. 1868 ◽  
Author(s):  
Jean-Marc Lelièvre ◽  
Nathalie Peynot ◽  
Sylvie Ruffini ◽  
Ludivine Laffont ◽  
Daniel Le Bourhis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Heat Shock ◽  
Transcriptional Activation ◽  
Luciferase Activity ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Nuclei ◽  
Cell Stage

In in vitro-produced (IVP) bovine embryos, a burst in transcriptional activation of the embryonic genome (EGA) occurs at the 8–16-cell stage. To examine transcriptional regulation prior to EGA, notably in response to heat stress, we asked (1) whether the spontaneous expression of a luciferase transgene that is driven by the minimal mouse heat-shock protein 1b (hspa1b) gene promoter paralleled that of HSPA1A during EGA in IVP bovine embryo and (2) whether expression of the endogenous heat-inducible iHSPA group member HSPA1A gene and the hspa1b/luciferase transgene were induced by heat stress (HS) prior to EGA. Using two culture systems, we showed that luciferase activity levels rose during the 40-h long EGA-associated cell cycle. In contrast, iHSPA proteins were abundant in matured oocytes and in blastomeres from the two-cell to the 16-cell stages. However, normalised results detected a rise in the level of HSPA1A and luciferase mRNA during EGA, when transcription was required for their protein expression. Prior to EGA, HS-induced premature luciferase activity and transgene expression were clearly inhibited. We could not, however, establish whether this was also true for HSPA1A expression because of the decay of the abundant maternal transcripts prior to EGA. In bovine embryos, heat-induced expression of hspa1b/luciferase, and most likely of HSPA1A, was therefore strictly dependent on EGA. The level of the heat-shock transcription factor 1 molecules that were found in cell nuclei during embryonic development correlated better with the embryo’s capacity for heat-shock response than with EGA-associated gene expression.

scholarly journals Chromatin Modifying Agents in theIn VitroProduction of Bovine Embryos

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Fabio Morato Monteiro ◽  
Clara Slade Oliveira ◽  
Letícia Zoccolaro Oliveira ◽  
Naiara Zoccal Saraiva ◽  
Maria Eugênia Zerlotti Mercadante ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nuclear Transfer ◽  
Epigenetic Reprogramming ◽  
Nuclear Reprogramming ◽  
Bovine Embryos ◽  
Aberrant Gene Expression ◽  
Low Efficiency ◽  
Aberrant Gene

The low efficiency observed in cloning by nuclear transfer is related to an aberrant gene expression following errors in epigenetic reprogramming. Recent studies have focused on further understanding of the modifications that take place in the chromatin of embryos during the preimplantation period, through the use of chromatin modifying agents. The goal of these studies is to identify the factors involved in nuclear reprogramming and to adjustin vitromanipulations in order to better mimicin vivoconditions. Therefore, proper knowledge of epigenetic reprogramming is necessary to prevent possible epigenetic errors and to improve efficiency and the use ofin vitrofertilization and cloning technologies in cattle and other species.

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