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Z Q Ma

Publications and source records attributed to Z Q Ma.

At least 19 recordsLinked to original sources
PubMed2005

Mapping QTL associated with resistance to Fusarium head blight in the Nanda2419 x Wangshuibai population. II: type I resistance.

Fusarium head blight (FHB) is a serious disease in wheat and barley affecting both yield and quality. To identify genes for resistance to infection, the RIL population derived from 'Nanda2419' x 'Wangshuibai' and the parents were evaluated for percentage of infected spikes (PIS) in four different environments. Using a 2,960 cM marker framework map constructed for this population, ten chromosome regions were detected for their association with type I resistance through interval mapping with Mapmaker/QTL, among which QTLs mapped in the intervals of Xwmc349--Xgwm149 on chromosome 4B, of Xwmc96--Xgwm304 on chromosome 5A and of Xgwm408--Xbarc140 on chromosome 5B were revealed in at least three environments and have Wangshuibai as the source of resistance alleles. Qfhi.nau-4B and Qfhi.nau-5A had larger effects and explained up to 17.5 and 27.0% of the phenotypic variance, respectively. To detect epistasis QTLs, two-locus interactions were examined by whole genome scan. Interactions of five locus pairs were found to have significant effects on type I resistance with the LOD score ranging 3.8-6.5 and four of them conferred resistance in parental phase. The one with the most significant effect was Xcfd42--Xgwm469 (6D)/Xwmc390-2--Xbd04 (2A) pair. No QTL x E interaction was detected for PIS. It was found that flowering time did not have significant effects on PIS in this population. Our studies indicated that Wangshuibai is useful for breeding for both type I and type II scab resistance and the markers associated with the QTLs could be used in marker-assisted selection and isolation of scab-resistance QTLs.

Chromosome Mapping↗
PubMed2004

Mapping QTL associated with resistance to Fusarium head blight in the Nanda2419 x Wangshuibai population. I. Type II resistance.

Scab disease caused by Fusarium spp. has been a major concern for both wheat producers and consumers. Deployment of scab-resistant varieties is the major strategy to curb this disease. To identify the scab resistance genes in wheat cv. Wangshuibai, we produced a F(6:7) recombinant inbred line (RIL) population by crossing Wangshuibai with the scab-susceptible cultivar Nanda2419. The RILs were evaluated for scab resistance in the field by single floret inoculation in two replicates in 2002 and one replicate in 2003. The number of diseased spikelets (NDS) and the length of diseased rachides (LDR) were investigated to reflect the Type II resistance. Among 654 simple sequence repeat (SSR) markers surveyed, 326 were found to be polymorphic between the parents. A partial molecular map was constructed with these markers that covered over 2,210 cM of the wheat genome. Six chromosome regions showed association with both NDS and LDR in a one-way anova analysis, even though the variation explained by them varied between the two traits. Eight intervals were detected for their association with Type II resistance through interval mapping, five of which were not identified in single-point analysis. The quantitative trait loci (QTL) with large effects were the ones in the interval of Xgwm533-3-Xgwm533-1 on chromosome 3B and in the interval of Xwmc539-Xbarc024 on chromosome 6B, whose alleles favoring resistance originate from Wangshuibai. In addition, a QTL whose resistance allele originated from Nanda2419 was consistently detected in the interval of Xs1021m-Xgwm47-1 on chromosome 2B. These results suggest that Wangshuibai is the major source for Type II resistance in this population. The markers associated with these QTL would facilitate the use of scab-resistant genes of Wangshuibai in scab resistance breeding programs of wheat.

Chromosome Mapping↗
PubMed2001

Cdc25B functions as a novel coactivator for the steroid receptors.

We have previously demonstrated that overexpression of Cdc25B in transgenic mice resulted in mammary gland hyperplasia and increased steroid hormone responsiveness. To address how Cdc25B enhances the hormone responsiveness in mammary glands, we showed that Cdc25B stimulates steroid receptor-dependent transcription in transient transfection assays and in a cell-free assay with chromatin templates. Surprisingly, the effect of Cdc25B on steroid receptors is independent of its protein phosphatase activity in vitro. The direct interactions of Cdc25B with steroid receptors, on the other hand, were evidenced in in vivo and in vitro assays, suggesting the potential direct contribution of Cdc25B on the steroid receptor-mediated transcription. In addition, p300/CBP-associated factor and CREB binding protein were shown to interact and synergize with Cdc25B and further enhance its coactivation activity. Thus, we have uncovered a novel function of Cdc25B that serves as a steroid receptor coactivator in addition to its role as a regulator for cell cycle progression. This dual function might likely contribute to its oncogenic action in breast cancer.

Acetyltransferases↗
PubMed2001

[Cloning and characterization of pathogenesis-related protein 1 from wheat-H. villosa translocation lines].

A Triticum aestivum-Haynaldia villosa 6VS/6AL translocation line contained powdery mildew resistance gene Pm21 which is effective against all the current biotypes of Erygsiphe gramins. Cloning of the related genes for powdery mildew resistance is significance for understanding its resistance mechanism and disease resistance breeding. Using RT-PCR and RACE technology, a wheat pathogenesis related protein 1 cDNA clone (TaPr-1) corresponding to a mRNA differentially induced in resistant 6VS/6AL translocation line compared to susceptible wheat cultivar "Yangmai 5" by powdery mildew infection was isolated and characterized. This sequence contained 823 bp and had an open reading frame (ORF) containing 164 amino acids with 24 amino acids in the putative signal peptide and 140 amino acids comprising the mature peptide (15.1 kD). The deduced amino acid sequence showed close homology to PR-1 like proteins, which have been isolated from many plants. Northern blot analysis revealed the most abundantly accumulation of the corresponding mRNA 12 h after infection in translocation line (6VS/6AL). The obviously difference in the expression of the PRw-1 was also observed between resistant translocation line (6VS/6AL) and susceptible parent "Yangmai 5", it showed the TaPr-1 gene is related to powdery mildew resistance. Southern blot indicated that the wheat genome contains more than one copies of TaPr-1 genes, and there are polymorphism between translocation lines and "Yanmai 5", the result shows that 6VS may contain TaPr-1 genes.

Amino Acid Sequence↗
PubMed2001

[Molecular markers linked to dwarf gene Rht3 in wheat].

The dwarf gene Rht3 derived from Tom Thumb variety, a Tibetan wheat of China, is a dominant gene with the insensitivity to gibberellic acid. Rht3 shows to depress alpha-amylase activity and hence enchance the resistance to preharvest sprouting mainly through its effect on the expression of alpha-Amy1. Near isogenic lines with Rht3 and their segregating population were analyzed by PCR and RFLP techonology. In RAPD analysis, out of 310 random primers (10 bp) screened, only three primers of UBC389, OPV-06 and S1060 revealed polymorphisms in NIL from 310 random primers. Fragments S1060(1900) and S1060(2000) amplified by primer S1060 were shown to be linked to Rht3 with a genetic distance 7.1 cM and 9.2 cM. Fifty-three probes specific for short arms of homoeologous group 4 were screened in RFLP analysis. Xpsr584, XksuF8 and Xcdo38 showed polymorphisms between the NIL. The linkage analysis indicateded that Xpsr584 was linked to Rht3 with a genetic distance 8.0 cM.

Genes, Plant↗
PubMed2000

Risk of tuberculosis infection and tuberculous meningitis after discontinuation of Bacillus Calmette-Guerin in Beijing.

In Beijing, the notification rate of smear-positive tuberculosis (TB) has been below 20 per 100,000 since 1986, and continues to decline. To accurately measure the risk of TB infection in a population in which the results of tuberculin skin testing were not confounded by vaccination with Bacillus Calmette-Guerin (BCG), BCG vaccination at birth was discontinued from 1988 in Shun-yi County. In 1995, the prevalence of TB infection among 12,836 primary school children aged 6 to 7 yr and without BCG scars was 1.4%, giving an estimated annual risk of infection of 0.19% (95% confidence interval: 0.16 to 0.22%). The prevalence of TB infection in children aged 5 to 9 yr in Beijing in 1950 was 46%. The number of cases of tuberculous meningitis did not increase after discontinuation of BCG. We conclude that discontinuation of BCG had no detectable harmful effects, and that control of TB in Beijing has markedly reduced the prevalence of TB infection since 1950.

BCG Vaccine↗
PubMed2000

Identification of RAPD markers tightly linked to wheat powdery mildew resistance gene Pm6.l.

Pm6 transferred from Triticum timopheevii L. to common wheat, is an effective resistance gene to powdery mildew disease caused by Erysiphe graminis f. sp. tritici. The RAPD technique, employing a total of 700 decamer primers, was used to identify polymorphic markers between resistant (IGVI463) and susceptible (Prins) near-isogenic lines. Primer OPV20 produced a 2,000 base pair (bp) reproducible fragment only in the resistant near-isogenic line. The 2,000-bp DNA fragment was present in all other introgression lines containing Pm6. Using the F2 mapping population from a cross of IGVI-463 (PI170914/7*Prins) x Prins, Pm6 was shown to be closely linked to the marker OPV20-2000 at a genetic distance of 3.0 +/- 2.2 cM. The marker was successfully used in detecting the presence of Pm6 in different genetic backgrounds.

Breeding↗
PubMed2000

Follicular gastritis associated with Helicobacter pylori.

In order to understand the pathogenesis of gastric lymphoma, we investigated the association of H.pylori infection with lymphoid follicular hyperplasia. Eighty-four gastric specimens removed for gastroduodenal ulcer were histologically examined. The distribution and prevalence of H. pylori, neutrophilic and lymphocytic infiltration, mucosal atrophy, intestinal metaplasia, and lymphoid follicles were scored. The lymphoid follicles were more frequently observed in H.pylori positive cases. They indicated a positive correlation with the score of H. pylori. When follicular gastritis (FG) was defined as a case in which the secondary lymphoid follicles (Lf2) numbered two or more per one centimeter of mucosa in the pyloric gland area of the lesser curvature, twenty specimens out of the 84 (24%) fit that definition. All of the FG cases were H.pylori positive, and they displayed high H. pylori scores. It was supposed that most FG cases would ultimately lead to atrophic gastritis, whereas H.pylori would gradationally decrease or disappear in accordance with the aging and progression of intestinal metaplasia. The histological features of the FG cases, however, were similar to the background mucosal state of early-stage MALT-type gastric lymphoma. We may conclude that H. pylori infection is one cause of the FG, which may be a high-risk condition that gives rise to MALT-type gastric lymphoma.

Adolescent↗
PubMed1999

Induction of mammary gland hyperplasia in transgenic mice over-expressing human Cdc25B.

Cdc25 A and B are dual-specificity phosphatases which have been implicated in neoplastic transformation. Although Cdc25A and Cdc25B have been found to be over-expressed in many cancer cell lines and primary tumors, the physiological roles of Cdc25A and B in vivo are largely undefined. To investigate the roles of these proteins in the oncogenic transformation of the mammary gland we used the mouse mammary tumor virus (MMTV) promoter to target over-expression of the Cdc25B transgene in the mammary glands of transgenic mouse lines. Here we report that the over-expression of Cdc25B enhances the proliferation of mammary epithelial cells resulting in the formation of precocious alveolar hyperplasia. At the molecular level, marked increases in cyclin D1 protein have been found in transgenic mammary epithelial cells. The accelerated growth rate of the mammary epithelial cells could also be attributed to the increased levels of cyclin E/cdk2 activity. In addition, a pronounced decrease in apoptosis was also observed during the involution of mammary gland. The reduction of apoptosis during involution correlated well with the reduced expression of c-myc and p53, both of which have been implicated in apoptosis. Taken together, our results clearly indicate that the deregulated expression of Cdc25B generates mammary gland hyperplasia.

Animals↗
PubMed1999

Decrease of the number of opioid receptors and of the responsiveness to morphineduring neuronal differentiation induced by 17beta-estradiol in estrogen receptor-transfected neuroblastoma cells (SK-ER3).

Estrogens modulate the density of opioid receptors in selected brain areas; however, it is not clear whether they exert such an effect directly on the cells which express the opioid receptors. Therefore, we analyzed the binding of [3H]-diprenorphine in human neuroblastoma cells stably transfected with the estrogen receptor cDNA (SK-ER3 cell line). A 16-hour exposure of these cells with 1 nM 17beta-estradiol induces a progressive morphological differentiation which appears clearly established 6 days after the suspension of the treatment. The binding of [3H]-diprenorphine was then measured immediately after the exposure to 17beta-estradiol (16 h) as well as 6 days later. The results shows that the number of opioid receptors in SK-ER3 cells is unaffected at 16 h but appears significantly reduced at 6 days. This effect is blocked by the estrogen antagonist ICI-182780, and is coincident to a decrease of the inhibitory effect of morphine on cyclic AMP accumulation. Binding experiments performed using selective ligands suggest that the micro subclass of opioid receptors is down-regulated by estradiol in SK-ER3 cells.

Cell Differentiation↗
PubMed1997

Dopaminergic phenotype induced by oestrogens in a human neuroblastoma cell line.

Oestrogens are the key factor in the sexual differentiation of the mammalian brain and play an important role in the activity of selected areas of the mature brain. To pursue the study of oestrogen action on neural cells at the molecular level, we developed a human neuroblastoma cell line (SK-ER3) expressing the oestrogen receptor (ER). Treatment of these cells with 17beta-oestradiol causes growth arrest and morphological and biochemical differentiation. The aim of the present study was to investigate whether oestrogen-differentiated SK-ER3 neuroblastoma cells acquire the ability to synthesize a specific neurotransmitter and whether the growth arrest previously reported can be ascribed to the blockage of the cells at a specific stage of the cell cycle. The results presented here indicate that oestrogens induce accumulation of SK-ER3 cells in the G0 phase of the cell cycle, underscoring the acquisition of a mature neural phenotype upon hormonal treatment. Most importantly, we show that in the differentiated cells the content of tyrosine hydroxylase and Na+-dependent dopamine uptake is significantly augmented, proving that the oestrogen-differentiated SK-ER3 cells can synthesize and store a specific neurotransmitter. In addition, we prove that the dopamine accumulated in differentiated SK-ER3 cells can be released. These studies therefore suggest that oestrogen treatment results in the acquisition of a fully functional dopaminergic phenotype of SK-ER3 cells. Ample evidence shows a link between dopaminergic neurons and oestrogen activity in hypothalamic and non-hypothalamic areas of the mammalian brain. Our study indicates that oestrogens might play a primary role in committing undifferentiated neuroblasts towards the dopaminergic phenotype.

Dopamine↗
PubMed1996

Frequencies and sequence characteristics of di-, tri-, and tetra-nucleotide microsatellites in wheat.

Microsatellites have emerged as an important source of genetic markers for eukaryotic genomes. In this report, two wheat (Triticum aestivum L.) genomic libraries were screened for several di-, tri-, and tetranucleotide tandem repeats. Clones containing (AC)n, (AG)n, (TCT)n, and (TTG)n repeats were isolated and sequenced. On average, there was one (AC)n microsatellite every 292 kbp and one (AG)n microsatellite every 212 kbp. The trinucleotide tandem repeats (TCT)n and (TTG)n were about 10 times less common than the two dinucleotide tandem repeats tested and tetranucleotide tandem repeats were rare. Many of the microsatellites had more than 10 repeats. The maximum repeat number found for (AC)n was 36 and for (TCT)n was more than 50. The prevailing category of (AG)n microsatellites from (AG)n isolates was perfect repeats. About half of the (AC)n microsatellites were compound repeats, while most of the (TCT)n microsatellites were imperfect repeats. In a small sample, (TTG)n microsatellites consisted mainly of compound repeats. The most frequently associated repeats were (AC)n with (AG)n, (TCT)n with (TCC)n, and (TTG)n with (TGG)n. Among 32 pairs of microsatellite primers surveyed, seven produced polymorphic products in the expected size range and these loci were mapped using a hexaploid wheat mapping population or aneuploid stocks.

Base Sequence↗
PubMed1996

Cross-coupling between insulin and estrogen receptor in human neuroblastoma cells.

Insulin is a well known mitotic agent for neuroblastoma cells. Human SK-N-BE neuroblastoma cells stably transfected with the estrogen receptor, however, undergo growth arrest and differentiation when treated with insulin. These effects were shown to be due to an insulin-dependent activation of the unliganded estrogen receptor. Here, we demonstrate that this activation involves the AF-2 COOH-terminal domain of the estrogen receptor and that the communication between estrogen and insulin receptor systems occurs via selected and specific transduction signals. In fact, by the use of dominant negative and dominant positive mutants we demonstrate that p21ras is essential for insulin and estrogen receptor coupling. With pharmacological tools, we prove that PI 3'kinase does not contribute to this cross-talk and that protein kinase C triggers transduction signals that act in synergism with p21ras. These results prove the intricacy of all these intracellular paths of communication. The finding that, in neuroblastoma cells, selected signal transduction systems are involved in the insulin-dependent activation of estrogen receptor is of particular interest considering that estrogen receptor might restrict the role played by insulin during the differentiation of neural cells and interfere with its proliferative potential while allowing its regulation of other functions related to cell survival.

Cell Differentiation↗
PubMed1995

Estrogenic control of monoamine oxidase A activity in human neuroblastoma cells expressing physiological concentrations of estrogen receptor.

Several lines of evidence support the hypothesis of a role played by estrogens in the manifestation of affective disorders in women. The analysis of the mechanism of action of a number of antidepressant drugs clearly demonstrated the involvement of the catecholaminergic system in the etiology of these complex behavioral pathologies. The present in vitro study was therefore undertaken to investigate the presence of a functional link between estrogen and catecholamine metabolism in cells of neural origin. The model system utilized was a human neuroblastoma cell line which was obtained by stable transfection of the estrogen receptor cDNA (SK-ER3). The present study shows that in SK-ER3 activation of the estrogen receptor correlates with a marked decrease in monoamine oxidase A activity. This effect is observed following treatment with a physiological concentration of 17 beta-estradiol and can be blocked by the specific antagonist of the steroid receptor, ICI 182,780. Dibutyryl cyclic AMP acting, like estrogens, on the state of differentiation of SK-ER3 cells did not affect monoamine oxidase A activity. The present study provides strong evidence of a strict relationship between estrogen receptor and monoamine oxidase A activity in human cells of neural origin, thus favoring the hypothesis of an antidepressive effect of estrogens exerted via inhibition of the monoamine oxidative pathway.

Brain Neoplasms↗
PubMed1995

Inheritance and chromosomal locations of male fertility restoring gene transferred from Aegilops umbellulata Zhuk. to Triticum aestivum L.

Restriction fragment length polymorphism (RFLP) markers were used to map male fertility restoring gene that was transferred from chromosome 6U of Aegilops umbellulata Zhuk. to wheat. Segments of chromosome 6U bearing the gene that restore fertility to T. timopheevi Zhuk. male sterile cytoplasm were identified in all four translocation lines by two probes, BCD21 and BCD342. Lines 040-5, 061-1 and 061-4 are T6BL.6BS-6U translocations, while line 2114 is a T6AL.6AS-6U translocation. Line 2114 has a much larger 6U chromosomal segment and lower frequency of transmission of male gametes with the alien segment than the other three lines. The restoring gene carried by the 6U segment in 2114 showed high expressivity and complete penetrance. This restoring gene is designated Rf6. A homoeologous chromosome recombination mechanism is discussed for the alien gene transfer.

Chromosome Mapping↗
PubMed1995

Expression of early genes in estrogen induced phenotypic conversion of neuroblastoma cells.

Estrogens are known to modulate the growth rate and differentiation state of a number of cells. In uterine, as well as in mammary tumor cells, estrogen-dependent proliferation and differentiation are correlated to a series of biochemical responses, including increased expression of proto-oncogenes such as: c-fos, c-jun and c-myc. Since estrogens were shown to regulate the proliferation and the differentiation state of cells of nervous origin, the aim of the present study was to investigate whether these effects were associated to changes in the expression of early genes. In the model system utilized, the human cell line SK-ER3, an increase in c-fos mRNA and Fos protein without change of c-jun and related genes mRNA concentration was observed after short term treatment with 17 beta-estradiol (E2). A significant decrease of c-fos, c-jun and jun-D proto-oncogene mRNA levels were found after prolonged hormonal treatment. The exposure to the hormone did not determine any change in N-myc expression. Since the three protooncogene mRNAs are rapidly induced following estrogen treatment in other cell systems and target tissues, it is concluded that the estrogen-induced differentiation of neuroblastoma cells is correlated to a pattern of expression of early genes that might be peculiar for the activity of this hormone in neural cells.

Blotting, Northern↗
PubMed1994

Insulin-like growth factors activate estrogen receptor to control the growth and differentiation of the human neuroblastoma cell line SK-ER3.

The neuroblastoma cell line SK-ER3, which is stably transfected with the estrogen receptor (ER), was used to study the effect of insulin and insulin-like growth factors (IGF-I and IGF-II) on growth and morphological differentiation induced by estrogens. The data demonstrate that insulin and related growth factors control the growth and morphological differentiation of the cell line expressing the ER, but not of the parental cell line. Effects elicited by the growth factors in SK-ER3 cells can be blocked by ER antagonists. Transient transfection studies further confirm an effect of the IGFs in modulation of ER-activated promoters. The results presented support the hypothesis of the existence of cross-talk between membrane and intracellular receptors and provide evidence for physiological consequences of the activation of such a pathway of communication. The present study is of particular interest with regard to the theory of prenatal involvement of the ER in maturation of nerve cells. It could, in fact, be hypothesized that IGF-I and IGF-II, present in high concentrations in the developing brain, might activate the ER expressed in several embryonic brain nuclei.

Animals↗