鸭IL-2基因启动子的克隆、多态性与表达的关联分析

为研究鸭IL-2基因调控区单核苷酸多态性对其转录调控的影响,克隆获得了鸭IL-2基因启动子2 850 bp序列,与人、小鼠和原鸡的同源性分别为35.37%,37.52%和34.74%。其中,-1 400/-1 000存在集中的核心转录因子结合位点。对鸭IL-2基因启动子(-1 932/-742)进行单核苷酸多态检测和遗传多态性分析发现,该区域存在两个突变位点(C-1353A、C-1406T),且均处于Hardy-Weinberg极不平衡状态;等位基因A均为优势等位基因。单核苷酸多态与其表达水平的相关性分析发现,突变位点不同基因型与IL-2基因mRNA表达水平和IL-2蛋白水平均无显著相关关系,但基因型AA个体的mRNA表达量均高于其他基因型个体(P>0.05),表明鸭IL-2启动子等位基因A可能有促进IL-2基因转录的趋势。研究结果为IL-2基因转录调控机制的研究提供了理论基础。     

A G protein-coupled receptor is a plasma membrane receptor for the plant hormone abscisic acid

The plant hormone abscisic acid (ABA) regulates many physiological and developmental processes in plants. The mechanism of ABA perception at the cell surface is not understood. Here, we report that a G protein-coupled receptor genetically and physically interacts with the G protein alpha subunit GPA1 to mediate all known ABA responses in Arabidopsis. Overexpressing this receptor results in an ABA-hypersensitive phenotype. This receptor binds ABA with high affinity at physiological concentration with expected kinetics and stereospecificity. The binding of ABA to the receptor leads to the dissociation of the receptor-GPA1 complex in yeast. Our results demonstrate that this G protein-coupled receptor is a plasma membrane ABA receptor.     

猪IGF-2基因内含子3突变检测及其多态性分布

采用错配PCR-RFLP法,检测8个品种314头猪IGF-2基因内含子3的3072位点多态性及其在群体中的分布.结果表明:引入错配碱基构造出新的酶切位点,在很大程度上降低了试验成本且不影响基因型判定结果.IGF-2基因内含子3的3072位点(G→A)变异多态在猪群中分布差异极显著.国外品种猪中等位基因A的频率高于我国地方品种猪,我国地方品种猪(二花脸猪、梅山猪、五指山猪、淮猪)群体中绝大多数为GG基因型;而国外品种猪(长白猪、大约克猪、杜洛克猪)群体中GA和AA基因型频率分别为60%～70%和20%～30%.由杜洛克猪与二花脸猪、梅山猪杂交育成的苏太猪,其群体中GA基因型频率接近78%,大大超过地方品种猪.     

β-Fg C448 G/A基因多态性、Fg水平与心肌梗死发生率的关系

目的:探讨β-Fg C 448 G/A基因多态性对血浆Fg水平的影响及其与心肌梗死(MI)发生率的关系.方法:应用多聚酶链反应-限制性片段长度多态性(PCR-RFLPs)的方法分析β-Fg C448 G/A基因多态性;比浊法测定血浆Fg水平.结果:75例MI患者(病例组)血浆Fg水平(3.73±1.08) g/L高于156例对照者(对照组)血浆Fg水平(3.08±0.71) g/L(P＜0.01).A448基因携带者血浆Fg水平高于GG基因型者(P＜0.05).病例组与对照组A448等位基因频率分别为0.313、0.276,二者比较有统计学意义(P＜0.01).结论:β-Fg C 448 G/A基因多态性与血浆Fg水平关联,A448基因携带者血浆Fg水平增高使MI易感性增加.     

A yeast gene that is essential for release from glucose repression encodes a protein kinase

The SNF1 gene plays a central role in carbon catabolite repression in the yeast Saccharomyces cerevisiae, namely that SNF1 function is required for expression of glucose-repressible genes. The nucleotide sequence of the cloned SNF1 gene was determined, and the predicted amino acid sequence shows that SNF1 encodes a 72,040-dalton polypeptide that has significant homology to the conserved catalytic domain of mammalian protein kinases. Specific antisera were prepared and used to identify the SNF1 protein. The protein was shown to transfer phosphate from adenosine triphosphate to serine and threonine residues in an in vitro autophosphorylation reaction. These findings indicate that SNF1 encodes a protein kinase and suggest that protein phosphorylation plays a critical role in regulation by carbon catabolite repression in eukaryotic cells.     

Glucose-6-phosphatase and the exchange of glucose with glucose-6-phosphate

An equation is presented which makes it possible to estimate the exchange activity of glucose-6-phosphatase, as a percentage of the hydrolytic activity, for a given concentration of substrate and acceptor. The quantitative significance of the exchange-inhibition phenomenon is discussed.     

A genetic polymorphism in the renin gene of Dahl rats cosegregates with blood pressure

Blood pressure is influenced by multiple genetic loci whose identities are largely unknown. A restriction fragment length polymorphism (RFLP) in the renin gene was found between Dahl salt-hypertension-sensitive (S) and Dahl salt-hypertension-resistant (R) rats. In an F2 population derived from crossing S and R rats, the renin RFLP cosegregated with blood pressure. One dose of the S-rat renin allele was associated with an increment in blood pressure of approximately 10 mmHg, and two doses of this allele increased blood pressure approximately 20 mmHg. From this it can be definitively concluded that in the rat the renin gene is, or is closely linked to, one of the genes regulating blood pressure.     

IGF2基因多态性检测与生长性状相关性分析

采集395头核心群的种猪耳样,采用PCR-SNaPshot方法检测长白猪和大白猪胰岛素样生长因子2(IGF2)基因内含子3的位点多态性,并分析各基因型与生长性状的相关性.结果表明,长白和大白猪中均存在3种基因型,大白猪3种基因型分布为:AA＞GA＞GG,长白猪3种基因型分布为:GA ＞AA＞GG.大白和长白猪的A等位基...     

Beta 1-6 branching of Asn-linked oligosaccharides is directly associated with metastasis

Neoplastic transformation has been associated with a variety of structural changes in cell surface carbohydrates, most notably increased sialylation and beta 1-6-linked branching of complex-type asparagine (Asn)-linked oligosaccharides (that is, -GlcNAc beta 1-6Man alpha 1-6Man beta 1-). However, little is known about the relevant glycoproteins or how these transformation-related changes in oligosaccharide biosynthesis may affect the malignant phenotype. Here it is reported that a cell surface glycoprotein, gp 130, is a major target of increased beta 1-6-linked branching and that the expression of these oligosaccharide structures is directly related to the metastatic potential of the cells. Glycosylation mutants of a metastatic tumor cell line were selected that are deficient in both beta 1-6 GlcNAc transferase V activity and metastatic potential in situ. Moreover, induction of increased beta 1-6 branching in clones of a nonmetastatic murine mammary carcinoma correlated strongly with acquisition of metastatic potential. The results indicate that increased beta 1-6-linked branching of complex-type oligosaccharides on gp 130 may be an important feature of tumor progression related to increased metastatic potential.     

A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity

Obesity is a serious international health problem that increases the risk of several common diseases. The genetic factors predisposing to obesity are poorly understood. A genome-wide search for type 2 diabetes-susceptibility genes identified a common variant in the FTO (fat mass and obesity associated) gene that predisposes to diabetes through an effect on body mass index (BMI). An additive association of the variant with BMI was replicated in 13 cohorts with 38,759 participants. The 16% of adults who are homozygous for the risk allele weighed about 3 kilograms more and had 1.67-fold increased odds of obesity when compared with those not inheriting a risk allele. This association was observed from age 7 years upward and reflects a specific increase in fat mass.     

Toll样受体4(896A/G)基因多态性与溃疡性结肠炎易感性的Meta分析

目的 研究Toll样受体4(TLR4)896A>G位点基因多态性与溃疡性结肠炎(UC)发病风险的关系。方法 检索相关英文及中文数据库筛选文献,以OR值及95%CI为效应指标,运用RevMan 5.2和Stata 11.0进行Meta分析和敏感性分析,并采用Egger′s test评价发表偏倚。结果 研究共纳入14篇文献,包括2 174例UC患者和3 134例对照者。Meta分析结果表明携带等位基因G的人群较携带等位基因A的人群患UC的风险性增加,在各个基因模型下均差异有统计学意义[等位基因模型G/A:OR=1.41,95%CI(1.21~1.66),P<0.000 1;显性模型AG+GG/AA:OR=1.37,95%CI(1.16~1.62),P=0.000 2;隐性模型GG/AA+AG:OR=3.74,95%CI(1.78~7.86),P=0.000 5;共显性模型AG/AA:OR=1.42,95%CI(1.07~1.87),P=0.01;共显性模型GG/AA:OR=3.85,95%CI(1.82~8.12),P=0.000 4]。亚组分析结果表明,在等位基因模型G/A、显性模型AG+GG/AA、共显性模型AG/AA下,差异仅在白种人中存在。结论 TLR4 896A>G基因多态性与UC易感性相关,携带等位基因G会增加白种人患UC的发病风险。由于该研究纳入有关亚洲人群及非洲人群的文献数量较少,相关结果需要更多研究予以验证。     

荷斯坦牛TLR6基因c.640G>A多态性与体细胞评分的相关分析

为寻找与乳房炎相关的分子标记,以期为荷斯坦牛的抗病育种提供理论基础,利用PCR SSCP技术和直接测序技术对宁夏农垦303头中国荷斯坦牛的TLR6基因进行了遗传多态性分析,利用一般线性模型分析TLR6基因c.640G>A突变位点与中国荷斯坦牛体细胞评分（SCS）以及各个因素之间的相关性。结果表明,中国荷斯坦牛TLR6基因c.640G>A突变位点与SCS值和胎次之间存在极显著和显著相关性,GA和AA基因型个体的SCS值极显著低于GG基因型个体（P<001）。因此,在中国荷斯坦牛育种中,可尝试将c.640G>A突变位点的GA基因型作为低SCC/SCS牛的优良基因型加以应用。     

Low plasma cholesterol levels caused by a short deletion in the apolipoprotein B gene

Familial hypobetalipoproteinemia is a syndrome in which the plasma levels of apolipoprotein B (apo-B) and cholesterol are abnormally low. A truncated species of apo-B was identified in the plasma lipoproteins of members of a kindred with familial hypobetalipoproteinemia. DNA sequencing studies on genomic clones and enzymatically amplified genomic DNA samples revealed a four-base pair deletion in the apo-B gene. This short deletion, which results in a frameshift and a premature stop codon, accounts for the truncated apo-B species and explains the low apo-B and low cholesterol levels in this family.     

Comment on "A G protein coupled receptor is a plasma membrane receptor for the plant hormone abscisic acid"

Liu et al. (Reports, 23 March 2007, p. 1712) reported that the Arabidopsis thaliana gene GCR2 encodes a seven-transmembrane, G protein-coupled receptor for abscisic acid. We argue that GCR2 is not likely to be a transmembrane protein nor a G protein-coupled receptor. Instead, GCR2 is most likely a plant homolog of bacterial lanthionine synthetases.     

Development of glyphosate-tolerant transgenic cotton plants harboring the G2-aroA gene

Given that glyphosate weed control is an effective strategy to reduce costs and improve economic outcomes of agricultural production in China,the development of glyphosate-resistant cotton holds great promise.Using an Agrobacterium-mediated transformation method,a new G2-aroA gene that encodes 5-enolpyruvylshikimate-3-phosphate synthase(EPSPS)was transformed into cotton cultivar K312.The transgenic cotton plants were regenerated from a callus tissue culture via kanamycin selection.Ten regenerated cotton plants were obtained and allowed to flower normally to produce fruit.The results from polymerase chain reaction(PCR)and Southern and Western blot analyses indicated that the target gene was integrated into the cotton chromosome and was expressed effectively at the protein level.The glyphosate tolerance analysis showed that the transgenic cotton had a high resistance to glyphosate.Further,even cotton treated with 45.0 mmol L~(–1) of glyphosate was able to slowly grow,bloom and seed.The transgenic cotton may be used for cotton breeding research of glyphosate-tolerant cotton.     

猪重要性状全基因组关联分析的研究进展

目的揭示大白猪丝氨酸/苏氨酸激酶32B (serine/threonine kinase 32B,STK32B) 基因外显子8多态性及其与母猪繁殖性状的关联。方法采用PCR产物直接测序法检测476头大白猪STK32B基因外显子8区域的SNP位点,结合2177窝母猪繁殖性能记录,采用最小二乘模型分析各SNP位点不同基因型及其单倍型组合对5个繁殖性状的影响。结果大白猪STK32B基因外显子8区域共检出3个SNP位点,包括2个同义突变位点 (A669G、C732T) 和1个错义突变位点 (C749T),分别以AA、CC、CC基因型和A、C、C等位基因的频率最高,3个位点的多态信息含量 (0.1450~0.1744) 和杂合度 (0.1574~0.1930) 总体不高。A669G位点的AA基因型可显著提高仔猪初生窝质量 (P<0.05);C732T位点与总产仔数、产活仔数、仔猪初生窝质量显著关联,其中TT基因型可显著提高总产仔数 (P<0.05),CT基因型可显著提高产活仔数和仔猪初生窝质量 (P<0.05);C749T位点的TT基因型可显著提高仔猪初生窝质量(P<0.05);3个位点单倍型组合ACC/ATC具有极显著提高总产仔数和产活仔数的效应 (P<0.01),ACC/ACT组合具有显著或极显著提高仔猪初生窝质量和断奶窝质量的效应 (P<0.05或P<0.01),ACC/GCT组合具有显著提高断奶仔猪数的效应(P<0.05)。结论研究结果初步揭示大白猪STK32B基因外显子8多态性与母猪繁殖性状显著关联,但3个位点单倍型组合的效应具有一定的性状特异性。     

籼稻长穗颈不育系福eA6的选育与应用

通过直接辐射诱变保持系D297B,获得其eui2突变体,定名福eB6;再通过与D297A回交转育成不包颈不育系福eA6.福eA6穗颈长-6.1 cm,比D297A(-10.6 cm)伸长了4.5 cm,显著缓解了包穗现象,且异交性能好,对GA3的敏感性也显著提高,并能保持原不育系D297A的优良农艺性状和产量性状.用福eA6繁殖制种每公顷只需喷施1次30-60 g GA3即可达到解除包穗目的,制种产量可提高8%左右.用福eA6组配的杂种F1与D297A的杂种F1无显著差异.     

A common genetic variant is associated with adult and childhood obesity

Obesity is a heritable trait and a risk factor for many common diseases such as type 2 diabetes, heart disease, and hypertension. We used a dense whole-genome scan of DNA samples from the Framingham Heart Study participants to identify a common genetic variant near the INSIG2 gene associated with obesity. We have replicated the finding in four separate samples composed of individuals of Western European ancestry, African Americans, and children. The obesity-predisposing genotype is present in 10% of individuals. Our study suggests that common genetic polymorphisms are important determinants of obesity.     

牦牛MSTN基因内含子2多态性及与生长性状的相关性

采用PCR-SSCP技术对大通牦牛、甘南牦牛和天祝白牦牛(共277头)肌肉抑制素基因(MSTN)内含子2的部分序列进行了多态性研究,分析该基因与牦牛生长性状的相关性.结果表明,牦牛MSTN基因内含子2存在2个等位基因和3种基因型.在该基因座上,甘南牦牛、天祝白牦牛呈Hardy-Weinberg平衡状态,大通牦牛呈不平衡...