Study on the Gene Transcription Level of Hippocampus NGF in C_(57) Mouse Development

β-Nerve growth factor (β NGF) mRNA levels in hippocampa from C57BL/6J mice of different ages were compared by semi-quantitative RT-PCR method, taking β-actin gene as an internal control. The levels of 6-and 12-month-old C57 mice were much lower compared with that of the l-month-old mouse. However, there was no significant difference between these two groups. This result suggests that gene transcription level of hippocampus β NGF in a C57, mouse descends evidently as it grows up. Base T at Site 294 of β NGF cDNA was substituted by C in the C57, mouse, as revealed by DNA sequencing for the first time. Nevertheless, this polymorphism of nucleotide did not make any difference in amino acid composition.

Stochastic resonance induced by a multiplicative periodic signal in the gene transcriptional regulatory system with correlated noises

This paper investigates the stochastic resonance （SR） induced by a multiplicative periodic signal in the gene transcriptional regulatory system with correlated noises. The expression of the signal-to-noise ratio （SNR） is derived. The results indicate that the existence of a maximum in SNR vs. the additive noise intensity α the multiplicative noise intensity D and the cross-correlated noise intensity λ is the identifying characteristic of the SR phenomenon and there is a critical phenomenon in the SNR as a function of λ, i.e., for the case of smaller values of noise intensity （α or D）, the SNR decreases as λ increases; however, for the case of larger values of noise intensity （α or D）, the SNR increases as λ increases.

Glucose Metabolism During Kunming Mouse Preimplantation Development:Analysis of Gene Transcription in Embryos in Vivo

In order to investigate glucose metabolism pathways and their changes in Kunming mouse preimplantation 1-,2-,4-,8-cell,and morula embryos,the mRNA level for the genes involved in glucose metabolism was tested by nested RT-PCR on embryos at different development stages in vivo.These genes were glucose 6-phosphate dehydrogenase(G6PDH),phospho-fructokinase(PFK),and phosphoglucomutase(PGM),representing pentose phosphate pathway(PPP),glycolysis,and glycogensis and glycogenolysis respectively.Three sets of inner and outer primers were designed and synthesized based on cDNA sequences of G6PDH,PFK and PGM.RT-PCR results revealed that G6PDH gene transcription was found in Kunming mouse 1-8 cell embryos,and not in morula embryos;it indicated that 1-8 cell embryos may metabolize glucose by pentose phosphate pathway,but morula embryos can not do so.PFK gene transcription was found in 1-8 cell and morula embryos;it is probable that there exists glycolysis in those embryos.PGM gene transcription was not found in 1-8 cell and morula embryos,so glycogenesis and glycogenolysis in these embryos were not present.

Ceruloplasmin or Fibronectin Synergism with Quartz Dust on Stimulating Collagen Gene Transcription in Human 2BS Fibroblast

Human α1(Ⅰ), α2(Ⅰ) and α1(Ⅲ) cDNA probes and RNA dot hybridization were employed to quantitate collagen mRNA changes after adding silica dust into the media of human 2BS fibroblasts. At all dosages used (100, 200, 500 and 1000μg), the α1(Ⅰ), α2(Ⅰ)and α1(Ⅲ) mRNA levels increased one day after dusting. At the same dosage of silica (100μg), α1(Ⅲ) mRNA increased earlier than type Ⅰ collagen mRNA did. The type Ⅰ and type Ⅲ collagen mRNA contents in the experimental groups were higher than those in control on days 3, 5, 7 and 9. The effect of ceruloplasmin (Cp) and fibronectin (Fn) on collagen mRNA synthesis was also studied, after adding silica dust, Cp or Fn into the media of human 2BS fibroblast. The results showed that Cp and Fn have stimulating effect on collagen mRNA production. When both Cp and silica dust were added into cell culture media, the collagen mRNA level was increased more than those of adding either Cp or silica dust alone. Similar situations were found for Fn. Cp (or Fn) synergism with silica dust on stimulating transcription of human collagen gene was suggested

Stochastic resonance in the gene transcriptional regulatory system subjected to noises

We have investigated in the adiabatic limit the phenomenon of stochastic resonance in the gene transcriptional regulatory system subjected to an additive noise, a multiplicative noise, and a weakly periodic signal. Using the general two-state approach for the asymmetry system, the analytic expression of signal-to-noise ratio is obtained. The effects of the additive noise intensity a, the multiplicative noise intensity D and the amplitude of input periodic signal A on the signal-to-noise ratio are analysed by numerical calculation. It is found that the existence of a maximum in the RSNR a and RSNR D plots is the identifying characteristic of the stochastic resonance phenomenon in the weakened noise intensity region. The stochastic resonance phenomena are restrained with increasing a and D, and enhanced with increasing A.

Study on the Gene Transcription Level of Hippocampus NGF in C57 Mouse Development

β-Nerve growth factor (β NGF) mRNA levels in hippocampa from C57BL/6J mice of different ages were compared by semi-quantitative RT-PCR method, taking β-actin gene as an internal control. The levels of 6-and 12-month-old C57 mice were much lower compared with that of the l-month-old mouse. However, there was no significant difference between these two groups. This result suggests that gene transcription level of hippocampus β NGF in a C57, mouse descends evidently as it grows up. Base T at Site 294 of β NGF cDNA was substituted by C in the C57, mouse, as revealed by DNA sequencing for the first time. Nevertheless, this polymorphism of nucleotide did not make any difference in amino acid composition.

Distinct regulatory mechanism of immunoglobulin gene transcription in epithelial cancer cells

The restriction of immunoglobulin(Ig)expression to B lymphocytes is well established.However,several reports have confirmed that the Ig gene can be expressed in many non-B cancer cells and/or some normal cells.Our aim is to determine whether the Ig gene promoter can be activated in non-B cancer cells and to identify the regulatory mechanism for Ig gene expression.Our results show that the Ig promoter of VH4-59 was activated in several non-B cancer cell lines.Moreover,two novel positive regulatory elements,an enhancer-like element at 2800 to 2610 bp and a copromoter-like element at 2610 to 2300 bp,were identified in two epithelial cancer cell lines,HeLa S3 and HT-29.The octamer element(59-ATGCAAAT-39)located in the Ig promoter,a crucial element for B-cell-derived Ig gene transcription,was also very important for non-B-cell-derived Ig gene transcription.More importantly,we confirmed that octamer-related protein-1(Oct-1),but not Oct-2,was a crucial transcriptional factor for Ig gene transcription due to its ability to bind to the octamer element of the Ig promoter in epithelial cancer cells.These results suggested the presence of a distinct regulatory mechanism for Ig gene expression in non-B cancer cells.

The RNF20/40 complex regulates p53-dependent gene transcription and mRNA splicing

p53 is a key transcription factor to regulate gene transcription.However,the molecular mechanism of chromatin-associated p53 on gene transcription remains elusive.Here,using unbiased protein affinity purification,we found that the RNF20/40 complex associated with p53 on the chromatin.Further analyses indicated that p53 mediated the recruitment of the RNF20/40 complex to p53 target gene loci including p21 and PUMA loci and regulated the transcription of p21 and PUMA via the RNF20/40 complex-dependent histone H2B ubiquitination(ubH2B).Lacking the RNF20/40 complex suppressed not only ubH2B but also the generation of the mature mRNA of p21 and PUMA.Moreover,ubH2B was recognized by the ubiquitin-binding motif of pre-mRNA processing splicing factor 8(PRPF8),a subunit in the spliceosome,and PRPF8 was required for the maturation of the mRNA of p21 and PUMA.Our study unveils a novel p53-dependent pathway that regulates mRNA splicing for tumor suppression.

Changes in the Photosynthetic Pigment Contents and Transcription Levels of Phycoerythrin-Related Genes in Three Gracilariopsis lemaneiformis Strains Under Different Light Intensities

Three Gracilariopsis lemaneiformis strains,including wild type and high-temperature-resistant cultivars 981 and 2007,were studied with the changes in their photosynthetic pigment contents and related gene transcription levels under different light intensities(10,60,100,and 200μmolm^(−2)s^(−1)).The three G.lemaneiformis strains had the following photosynthetic pigments with high-to-low contents:phycoerythrin(PE),phycocyanin(PC),allophycocyanin(APC),and chlorophyll a(Chl a).Among the three strains,cultivar 981 had the highest PE content,followed by cultivar 2007.The PC and APC contents were similar among the three strains,but they were higher in cultivars 981 and 2007 than in the wild type.The Chl a contents in the three G.lemaneiformis strains were equal.A low light intensity(10μmolm^(−2)s^(−1))promoted photosynthetic pigment accumulation in G.lemaneiformis and improved the relative PE gene transcription(peA and peB)in a short period(≤6 d).A high light intensity decreased the PE content.PebA and PebB,which catalyzed phycoerythrobilin synthesis,showed no compensatory upregulation at a low light intensity among the strains except for the wild type.At a high light intensity,transcription levels of pebA and pebB in the three strains were upregulated.This study provided an experimental basis for elucidating the photosynthesis of G.lemaneiformis.As key genes of algal growth,photo-synthesis-related genes served as useful gene markers for screening elite varieties with good traits in breeding.Cultivar 2007 was superior to cultivar 981 in terms of maintaining high pigment levels in a wide range of light intensities,which is the most suitable for aquaculture.

Genome-wide Nucleosome Occupancy and Organization Modulates the Plasticity of Gene Transcriptional Status in Maize

Nucleosomes are fundamental units of chromatin that play critical roles in gene regulation by modulating DNA accessibility. However, their roles in regulating tissue-specific gene transcription are poorly understood. Here, we present genome-wide nucleosome maps of maize shoot and endosperm generated by sequencing the micrococcal nuclease digested nucleosomal DNA. The changes of gene transcriptional status between shoot and endosperm were accompanied by preferential nucleosome loss from the promoters and shifts in the first nucleosome downstream of the transcriptional start sites （＋1 nucleosome） and upstream of transcriptional termination sites （-1 nucleosome）. Intrinsically DNA-encoded nucleosome orga- nization was largely associated with the capacity of a gene to alter its transcriptional status among different tissues. Compared with tissue-specific genes, constitutively expressed genes showed more pronounced 5＇ and 3＇ nucleosome-depleted regions as well as further ＋1 nucleosome to transcriptional start sites and -1 nucleosome to transcriptional termination sites. Moreover, nucleosome organization was more highly correlated with the plasticity of gene transcriptional status than with its expression level when examined using in vivo and predicted nucleosome data. In addition, the translational efficiencies of tissue-specific genes appeared to be greater than those of constitutively expressed genes. Taken together, our results indicate that intrinsically DNA-encoded nucleosome organization is important, beyond its role in regulating gene expression levels, in determining the plasticity of gene transcriptional status.

Distinct effects of nuclear membrane localization on gene transcription silencing in Drosophila S2 cells and germ cells

Nuclear envelope proteins have important roles in chromatin organization and signal-dependent transcriptional regulation. A previous study reported that the inner nuclear membrane protein, Otefin （Ote）, was essential for germline stem cell （GSC） maintenance via interaction with Smad complex. The interaction of Ore with the Smad complex recruits the barn locus to the nuclear periphery and subsequently results in bam transcriptional silencing, revealing that nuclear peripheral localization is essential for barn gene regulation. However, it remains unknown whether the nuclear peripheral localization is sufficient for barn silencing. To address this issue, we have established a tethering system, in which the Gal4 DNA binding domain （DBD） of the Flag：Gal4 DBD：Ote△LEM fusion protein physically interacts with the Gal4 binding sites upstream of bamP-gfp to artificially recruit the reporter gene gfp to the nuclear membrane. Our data demonstrated that the nuclear peripheral localization seemed to affect the expression of the target naked gene in S2 ceils. By contrast, in Drosophila germ cells, the nuclear membrane localization was not sufficient for gene silencing.

Features,Mechanisms and Applies of Post-transcriptional Gene Silencing in Transgenic Plants

Since transgene silencing was found in transgenic plants,many scholars have studied it extensively and considered that it has three functional mechanisms:post dependent gene silencing,transcriptional gene silencing,post transcriptional gene silencing.At the moment,people have mainly focused on the study of post transcriptional gene silencing and found its features:extensivity,conduction and peculiarity,also put forward some hypothesis for its mechanisms,for example,RNA threshold model,aberrant RNA model,inter or intra molecular base pairing model and so on.Furthermore,post transcriptional gene silencing is being applied in gene engineering of plants.Recently the people have found that post transcriptional gene silencing has bearing on capacity plants resisting virus.Many researchers have studied post transcriptional gene silencing,but there are some questions which need be solved in the future.This article summarizes progresses in features,mechanisms,applies of post transcriptional gene silencing about transgenic plants.

Molecular Characterization and Expression Analysis of TaZFP15, a C_2H_2-Type Zinc Finger Transcription Factor Gene in Wheat (Triticum aestivum L.)

Based on sequencing of part clones in a root subtractive cDNA library, an expressed sequence tag （EST） sharing high similarity to a rice C2H2 zinc finger transcription factor （ZFP15） was obtained in wheat. Through bioinformatics approach, the wheat C2H2-type ZFP gene referred to TaZFP15 has been identified and characterized. As a full-length cDNA of 670 bp, TaZFP15 has an open reading frame of 408 bp and encodes a 135-aa polypeptide. TaZFP15 contains two C2H2 zinc finger domains and each one has a conserved motif QALGGH. The typical L-box, generally identified in the C2H2 type transcription factors, has also been found in TaZFP15. Phylogenetic analysis suggested that TaZFP15 shares high similarities with rice ZFP15 （GenBank accession no. AY286473）, maize ZFP （GenBank accession no. NM_001159094） and a subset of other zinc-finger transcription factor genes in plant species. The expression of TaZFP15 was up-regulated by starved-Pi stress, showing a pattern to be gradually elevated along with the progression of the Pi-stress in a 23-h treatment regime. Similarly, the transcripts of TaZFP15 in roots were also induced by nitrogen deficiency, and abiotic stresses of drought and salinity. No responses of TaZFP15 were detected in roots to nutrition deficiencies of P, Zn, and Ca, and the external treatment of abscisic acid （ABA）. TaZFP15 could be specifically amplified in genome A, B, and D, and without variability in the sequences, suggesting that TaZFP15 has multi-copies in the homologous hexaploid species. Transgenic analysis in tobacco revealed that up-regulation of TaZFP15 could significantly improve plant dry mass accumulation via increasing the plant phosphorus acquisition capacity under Pi-deficiency condition. The results suggested that TaZFP15 is involved in mediation of signal transductions of diverse external stresses.

Myocardin-related transcription factor A cooperates with brahmarelated gene 1 to activate P-selectin transcription

Expression of P-selectin in injured or activated endothelia cells serves as a permissive step towards leukocyte recruitment and perpetuation of inflammation in the pathogenesis of atherosclerosis.P-selectin can be induced by pro-inflammatory stimuli via the transcription factor NF-κB,but the epigenetic mechanisms remain incompletely understood.Previously we reported that myocardin-related transcription factor A（MRTF-A）mediates the transactivation of a slew of adhesion molecules by oxidized low-density lipoprotein（oxLDL）,likely through a crosstalk with brahma-related gene 1（BRGl）,a chromatin remodeling protein.Here,we show that MRTF-A was both sufficient and necessary for the transactivation of P-selectin gene in endothelial cells treated with TNF-α.Depletion of MRTF-A using small interfering RNA（siRNA）abrogated the binding of BRGl on the P-selectin promoter.Overexpression of BRG1 up-regulated the activity of P-selectin promoter activity while BRGl knockdown attenuated P-selectin expression.Finally,BRGl silencing suppressed the accumulation of acetylated histone H3 and methylated histone H3K4,and altered the binding of NF-κB on the P-selectin promoter.Therefore,our data demonstrate an essential role for MRTF-A and BRGl in P-selectin transactivation in endothelial cells.

Activation of p^(38) mitogen activated protein kinase induced by lipopolysaccharide and its role in TNF a gene expression

Objective: To study the molecular mechanisms of TNF--a expression induced by lipopolysaccharide (LPS) for exploring novel methods to prevent or treat clinical patients with endotoxic shock. Methods:Protein kinase assay was used to detect the kinase activity stimulated by LPS; Con focal laser scan technique was used to show the translocation of p38 on the activation; RT PCR and reporter gene system were used to study the molecular mechanism of TNF -a gene transcription. Results: In RAW cells it was found that p38 was activated on the stimulation of LPS. and activated p38 moved into nucleus from cytosol; TNF--a mRNA increased on the stimulation of LPS and the increased promoter transactivity induced by LPS could be inhibited significantly by specific inhibitor for p38. Conclusion: p38 mitogen activated protein kinase (MAPK ) was activated by the stimulation of LPS,which brought about its entry to the nucleus to act on transcription factors to regulate cellular processes. p38 MAPK Is an important regulator of TNF--a gene expression induced by LPS.

Epigenetics of epithelial Na^+ channel-dependent sodium uptake and blood pressure regulation

The epithelial Na^＋ channel （ENaC） consists of α, β, γ subunits. Its expression and function are regulated by aldosterone at multiple levels including transcription. ENaC plays a key role in Na^＋ homeostasis and blood pressure. Mutations in ENaC subunit genes result in hypertension or hypotension, depending on the nature of the mutations. Transcription of αENaC is considered as the rate-limiting step in the formation of functional ENaC. As an aldosterone target gene, αENaC is activated upon aldosterone- mineralocorticoid receptor binding to the cis-elements in the αENaC promoter, which is packed into chromatin. However, how aldosterone alters chromatin structure to induce changes in transcription is poorly understood. Studies by others and us suggest that Dot1a-Af9 complex represses αENaC by directly binding and regulating targeted histone H3 K79 hypermethylation at the specific subregions of αENaC promoter. Aldosterone decreases Dot1a-Af9 formation by impairing expression of Dot1a and Af9 and by inducing Sgk1, which, in turn, phosphorylates Af9 at S435 to weaken Dot1a-Af9 interaction. MR attenuates Dot1a-Af9 effect by competing with Dot1a for binding Af9. Af17 relieves repression by interfering with Dot1a-Af9 interaction and promoting Dot1a nuclear export. Af17^-/- mice exhibit defects in ENaC expression, renal Na^＋ retention, and blood pressure control. This review gives a brief summary of these novel fndings.

Inter3D:Capture of TAD Reorganization Endows Variant Patterns of Gene Transcription

Topologically associating domain(TAD)reorganization commonly occurs in the cell nucleus and contributes to gene activation and inhibition through the separation or fusion of adjacent TADs.However,functional genes impacted by TAD alteration and the underlying mechanism of TAD reorganization regulating gene transcription remain to be fully elucidated.Here,we first developed a novel approach termed Inter3D to specifically identify genes regulated by TAD reorganization.Our study revealed that the segregation of TADs led to the disruption of intrachromosomal looping at the myosin light chain 12B(MYL12B)locus,via the meticulous reorganization of TADs mediating epigenomic landscapes within tumor cells,thereby exhibiting a significant correlation with the down-regulation of its transcriptional activity.Conversely,the fusion of TADs facilitated intrachromosomal interactions,suggesting a potential association with the activation of cytochrome P450 family 27 subfamily B member 1(CYP27B1).Our study provides comprehensive insight into the capture of TAD rearrangement-mediated gene loci and moves toward understanding the functional role of TAD reorganization in gene transcription.The Inter3D pipeline developed in this study is freely available at https://github.com/bm2-lab/inter3D and https://ngdc.cncb.ac.cn/biocode/tool/BT7399.

Studies on Cloning and Transformation of CBF1 Gene of Maize Grass

[Objective]It is revealed whether the similar maize transcriptional activator in CBF1 gene is regulatory cold resistance gene to lay the foundation for breeding new transgenic Forage Maize Varieties with high cold resistance ability.[Methods]In the present paper,the transcriptional factor gene CBF1 was Successfully cloned by PCR from the leaves of Arabidopsis.The sequence was preliminarily analyzed and plant expression vector was constructed.Then with agrobacterium-mediated transgene technique,CBF1 gene was introduced into maize SAUMZ1.[Results]PCR assay revealed that the CBF1 gene was integrated in the maize grass SAUMZ1 genome.Under different low temperature treatment,the relative electrolyte leakage percentage of transgenic plant was lower than Control.[Conclusion] The results showed that the cold-resistance of maize grass SAUMZ1 enhanced after transforming CBF1 gene.

Active Methyl Cycle and Transfer Related Gene Expression in Response to Drought Stress in Rice Leaves

Three rice varieties, Zhonghan 3, Shanyou 63 and Aizizhan, were used as materials in detecting differential active methyl cycle and transfer related gene expression in response to drought stress. The experiment was performed by gene chip and mRNA differential display technologies under the conditions of drought simulated with 10% PEG6000 solution. The results indicated that the methyl cycle could be activated in the leaves of Zhonghan 3 and Shanyou 63 but inhibited in the leaves of Aizizhan under drought stress. Furthermore, drought stress could induce the expression of a large number of methyltransferase genes, especially the transcription of Rubisco protein methylation related genes, which are beneficial for prevention of Rubisco protein oxidation and degradation, and drought stress could inhibit the transcription of DNA methyltransferase genes and histone methyltransferase genes. This result confirmed that the active methyl cycle and transfer related genes were involved in rice drought resistance.

Over-Expression of ICE1 Gene in Transgenic Rice Improves Cold Tolerance

ICE1, an Arabidopsis thaliana transcription factor gene, was cloned by RT-PCR and successfully transformed into rice variety Kenjiandao 10 by the Agrobacterium-mediated transformation method. PCR amplification and Southern blot analysis indicated that ICE1 had been integrated into rice genome. Compared with the non-transgenic plants, the transgenic plants exhibited high resistance to hygromycin B and were consistent with the Mendelian inheritance of a single copy of the transgenic ICE1. Under the low temperature stress, the transgenic plants showed the lower mortality rate and the increased proline content. These results suggest that the Arabidopsis ICE1 is functional in rice and the over-expression of ICE1 improves the tolerance to cold stress in rice.