Interaction of a surface acoustic wave with a two-dimensional electron gas

When a surface acoustic wave propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will attenuate the SAW. The coupling coefficient is calculated for the SAW propagating along an arbitrary direction. It is found that the coupling strength is largely dependent on the propagating direction. When the SAW propagates along the [011] direction, the coupling becomes quite weak.Comment: 3 figure

Global gene expression profiling of JMJD6- and JMJD4-depleted mouse NIH3T3 fibroblasts

Emerging evidence suggests Jumonji domain-containing proteins are epigenetic regulators in diverse biological processes including cellular differentiation and proliferation. RNA interference-based analyses combined with gene expression profiling can effectively characterize the cellular functions of these enzymes. We found that the depletion of Jumonji domain-containing protein 6 (JMJD6) and its paralog protein Jumonji domain-containing protein 4 (JMJD4) individually by small hairpin RNAs (shRNAs) slowed cell proliferation of mouse NIH3T3 fibroblasts. We subsequently performed gene expression profiling on both JMJD6- and JMJD4-depleted mouse NIH3T3 fibroblasts using the Affymetrix GeneChip Mouse Exon 1.0 ST Array. Here we report the gene profiling datasets along with the experimental procedures. The information can be used to further investigate how JMJD6 and JMJD4 affect gene expression and cellular physiology

Comparative transcriptional profiling analysis of the two daughter cells from tobacco zygote reveals the transcriptome differences in the apical and basal cells

<p>Abstract</p> <p>Background</p> <p>In angiosperm, after the first asymmetric zygotic cell division, the apical and basal daughter cells follow distinct development pathways. Global transcriptome analysis of these two cells is essential in understanding their developmental differences. However, because of the difficulty to isolate the <it>in vivo </it>apical and basal cells of two-celled proembryo from ovule and ovary in higher plants, the transcriptome analysis of them hasn't been reported.</p> <p>Results</p> <p>In this study, we developed a procedure for isolating the <it>in vivo </it>apical and basal cells of the two-celled proembryo from tobacco (<it>Nicotiana tabacum</it>), and then performed a comparative transcriptome analysis of the two cells by suppression subtractive hybridization (SSH) combined with macroarray screening. After sequencing, we identified 797 differentially expressed ESTs corresponding to 299 unigenes. Library sequence analysis successfully identified tobacco homologies of genes involved in embryogenesis and seed development. By quantitative real-time PCR, we validated the differential expression of 40 genes, with 6 transcripts of them specifically expressed in the apical or basal cell. Expression analysis also revealed some transcripts displayed cell specific activation in one of the daughter cells after zygote division. These differential expressions were further validated by <it>in situ </it>hybridization (<it>ISH</it>). Tissue expression pattern analysis also revealed some potential roles of these candidate genes in development.</p> <p>Conclusions</p> <p>The results show that some differential or specific transcripts in the apical and basal cells of two-celled proembryo were successfully isolated, and the identification of these transcripts reveals that these two daughter cells possess distinct transcriptional profiles after zygote division. Further functional work on these differentially or specifically expressed genes will promote the elucidation of molecular mechanism controlling early embryogenesis.</p

Protective effect of catalpol on isoproterenol-induced myocardial injury in Wistar rats

The neuroprotective effects of catalpol had been well demonstrated in many studies. Nevertheless, little work was done to investigate the cardioprotective effects of catalpol. This study was designed to explore whether catalpol protected myocardium against isoproterenol (ISO)-induced myocardial injury through attenuating oxidative stress and suppressing inflammation. Histopathological changes were assessed by hematoxylin and eosin staining. Results show that catalpol could effectively suppress the histopathological changes including myocardial structure damage and leucocyte infiltration. Oxidative stress and antioxidant status were also analysed. Results show that catalpol could significantly attenuate the increase of myocardial malondialdehyde (MDA) and renew the activities of superoxide dismutase (SOD). Furthermore, the results of real time reverse transcription polymerase chain reaction (RT-PCR) and Western-blot analysis showed that catalpol could inhibit the upregulation of the expressions of tumor necrosis factor-β (TNF-β) and interleukin-1β (IL-1β) caused by ISO. In conclusion, our data suggest that catalpol had a protective effect against ISO-induced cardiotoxicity in rat, by maintaining endogenous antioxidant enzyme activities and alleviating inflammatory response. This study provides novel insights that catalpol treatment could be an approach for the prevention of ischemic heart disease.Key words: Catalpol, isoproterenol, inflammation, oxidative stress, myocardial injury

Prmt7 is dispensable in tissue culture models for adipogenic differentiation

Protein arginine methylation is a common posttranslational modification that has been implicated in numerous biological processes including gene expression. The mammalian genome encodes nine protein arginine methyltransferases (Prmts) that catalyze monomethylation, asymmetric dimethylation, and symmetric dimethylation on arginine residues. Protein arginine methyltransferase 7 (Prmt7) is categorized as a type II and type III enzyme that produces symmetric dimethylated arginine and monomethylated arginine, respectively. However, the biological role of Prmt7 is not well characterized. We previously showed that Prmt5, a type II Prmt that associates with Brg1-based SWI/SNF chromatin remodeling complex, is required for adipocyte differentiation. Since Prmt7 also associates with Brg1-based SWI/SNF complex and modifies core histones, we hypothesized that Prmt7 might play a role in transcriptional regulation of adipogenesis. In the present study, we determined that the expression of Prmt7 did not change throughout adipogenic differentiation of C3H10T1/2 mesenchymal cells. Knockdown or over-expression of Prmt7 had no effect on lipid accumulation or adipogenic gene expression in differentiating C3H10T1/2 cells or in C/EBPalpha-reprogrammed NIH3T3 fibroblasts. Based on these results, we conclude that Prmt7, unlike Prmt5, is dispensable for adipogenic differentiation in tissue culture models