Quantitative trait loci (QTL) analysis for rice grain width and fine mapping of an identified QTL allele gw-5 in a recombination hotspot region on chromosome 5

Rice grain width and shape play a crucial role in determining grain quality and yield. The genetic basis of rice grain width was dissected into six additive quantitative trait loci (QTL) and 11 pairs of epistatic QTL using an F(7) recombinant inbred line (RIL) population derived from a single cross between Asominori (japonica) and IR24 (indica). QTL by environment interactions were evaluated in four environments. Chromosome segment substitution lines (CSSLs) harboring the six additive effect QTL were used to evaluate gene action across eight environments. A major, stable QTL, qGW-5, consistently decreased rice grain width in both the Asominori/IR24 RIL and CSSL populations with the genetic background Asominori. By investigating the distorted segregation of phenotypic values of rice grain width and genotypes of molecular markers in BC(4)F(2) and BC(4)F(3) populations, qGW-5 was dissected into a single recessive gene, gw-5, which controlled both grain width and length-width ratio. gw-5 was narrowed down to a 49.7-kb genomic region with high recombination frequencies on chromosome 5 using 6781 BC(4)F(2) individuals and 10 newly developed simple sequence repeat markers. Our results provide a basis for map-based cloning of the gw-5 gene and for marker-aided gene/QTL pyramiding in rice quality breeding.     

结核病房医院感染与抗生素使用相关性分析

目的：探讨临床抗菌药物应用与结核病房医院感染严重程度的相关性。方法：分析3年来我院结核病房医院感染209例共计221株病原菌,细菌鉴定采用法国梅里埃ATB细菌鉴定药敏分析仪,药敏试验联合应用微量测定法与K—B纸片法。结果：在221株病原菌中革兰阴性杆菌最多为112株,占50．7％,念珠菌75株,占33．9％。主要致病菌依次为白色念珠菌61株(27．6％),铜绿假单胞菌37株(16．8％),肺炎克雷伯菌25株(10．9％)。药敏试验表明细菌耐药明显增加,大多数革兰阴性杆菌对亚胺培南、阿米卡垦、头孢他啶较敏感,金黄色葡萄球菌对万古霉素100％敏感。每例结核病患者除抗结核药物外平均使用2．67种抗菌药物。结论：结核病房医院感染主要来源于内源性感染,其严重性与抗菌药物大量、重复使用密切相关。     

种子脱水耐性与糖的关系

糖类在植物种子中的累积随种子的发育阶段和种子类型不同而不同,并与种子脱水耐性的变化相联系。许多正常性植物种子的发育伴随着某些糖的累积,这些糖的累积已被认为在种子脱水耐性获得中起重要作用。但糖对种子脱水耐性的影响不是单独的,而是与ABA和蛋白质等物质协同作用。种子脱水耐性不仅与糖的种类和含量有关,而且与种子所处的生理状态和发育进程有关。本文综述了种子脱水耐性与糖关系的研究进展。     

兔抗人NESTIN抗血清的制备与鉴定(简报)

巢蛋白(nestin)属Ⅵ类中等纤维蛋白。最初在神经系统发育早期发现有该蛋白的表达。后在正常神经系统中发现仅在未分化的神经前体细胞中有nestin的短暂表达,分化后在神经元和神经胶质细胞中分别被NF(neurofilament,神经丝)和GFAP(Glial fibrillary acidic protein,神经胶质元纤维酸性蛋白)所代替。所以nestin的表达通常被视为神经前体细胞的标志之一。就我们所知,目前商品化nestin的抗体都是鼠抗鼠(克隆Rat401)的抗体,而人鼠之间该蛋白序列的同源性仅为50%左     

Stabilization of Metals in Subsurface by Biopolymers: Laboratory Drainage Flow Studies

Environmental contamination with heavy metals and radionuclides remains a major problem worldwide. The current clean-up methodologies are based on energy-intensive engineering processes, which are disruptive and costly. A new universal technology targeted for the permanent enclosure and fixation of nuclear and other extreme hazardous metallic wastes in subsurface sites is needed. Such technology will be useful in treating contamination at many sites in the U.S., with specific applications to Department of Energy (DOE) sites. Biopolymers are potential tools for such an innovative technology. Biopolymers have repeated sequences, and therefore provide ample opportunity for chemical reactions with metals, soil particles, and other biopolymers. They also have the additional ability of creating cross-linking interpenetrating networks that can encapsulate the contaminants. Based on this concept, in the present work five biopolymers (xanthan, chitosan, polyhydroxy butyrate, guar gum, polyglutamic acid) were investigated for potential use in the stabilization of metals in the subsurface. The effects of these biopolymers (used alone and in combinations) on soil characteristics (permeability, shear strength) and their metal uptake ability have been studied using laboratory drainage flow systems. Biopolymer solutions were run through the experimental sandpack columns, followed by copper solution and leaching agents (distilled water and hydrochloric acid). The permeability and shear strength of sand were evaluated. Copper uptake capacity of each biopolymer and combination of biopolymers was also studied along with subsequent leaching. All biopolymers tested improved sand characteristics (by decreasing permeability and increasing shear strength) and had good metal uptake ability (60–90%) with relatively low leachability (10–22%). While biopolymers used alone were more efficient in metal uptake, the combination of two biopolymers (xanthan and chitosan) had an increasing plugging effect. These results show the potential of using biopolymers in subsurface metal stabilization.     

湖南烙铁头蛇毒中一个新的舒缓激肽增强肽（TmF）

通过 70 %冷甲醇抽提、SephadexG 15分子筛和反相高效液相色谱C1 8层析 ,从湖南产烙铁头蛇毒 (Trimeresurusmucrosquamatus)冻干粉中纯化得到一个新的舒缓激肽增强肽 (BPP) ,命名为TmF。该小肽的氨基酸序列为pGlu Gly Arg Pro Leu Gly Pro Pro Ile Pro Pro (pGlu表示焦谷氨酸 )。序列结果分析表明 ,TmF和已经分离得到的BPPs有很高的序列同源性。MSI MS测定其分子量为 1.110 7kD。TmF的生物学活性和药理学活性检测的结果表明 ,它增强舒缓激肽 (BK) ( 1mg L)诱导的离体豚鼠回肠纵行肌收缩的活性为 ( 1.13± 0 .3)单位 (mg L) ;TmF ( 5 .0× 10 - 4mg kg)可以增强约 ( 14± 2 )mmHg的由BK( 5 .0× 10 - 5mg kg)诱导的舒张压下降 ;在抑制剂试验中 ,不同剂量的TmF和 5× 10 - 2 mg的血管紧张素转化酶保温 30min ,结果表明大约2 .0× 10 - 3mg的TmF表现出对ACE水解活性的半数抑制率 (IC50 )。     

几种不育剂在有害鼠类控制中的应用研究及其展望

随着急性化学剧毒灭鼠剂的逐渐被淘汰,慢性抗凝血灭鼠剂的广泛推广应用,近年来又出现了抗药性、适口性及灭鼠后鼠类种群迅速反弹等问题^[1]。在对有害啮齿动物控制应用研究中,一般是应用毒性的试剂来对其进行控制。用化学杀鼠剂防治,虽然见效快,但对环境造成了污染,误杀了大量的天敌动物和有益动物。干扰了森林生态系统的相对稳定性。于是,利用鼠类不育来控制鼠害的研究受到世人的重视,有望给鼠害防治技术带来一次革命。不育剂根据药物提取途径的不同可分为化学不育剂和植物型不育剂2种,但两者的作用原理是相同的。现以比较常用的几种不育剂的应用为例进行论述。     

Is Vitamin E Toxic to Neuron Cells?

Besides acting as potent free radical scavengers, tocopherols and tocotrienols have been known to have non-antioxidant properties such as the involvement of α-tocopherol (αT) in PKC pathway and the anti-cancer properties of γ-tocotrienol (γT3). This study aims to elucidate whether protective effects shown by αT and γT3 in H₂O₂-induced neuron cultures have anti-apoptotic or pro-apoptotic tendency toward the initiation of neuronal apoptosis. H₂O₂ is used to induce apoptosis in primary cerebellar neuron cultures which is attenuated by pretreatment of αT or γT3 at concentrations ≤10 μM. Similar to our previous work, γT3 was found to be neurotoxic at concentrations ≥100 μM, whereas αT showed no neurotoxicity. Cellular uptake of γT3 was higher than that of αT. Treating cells simultaneously with either γT3 or αT and with then H₂O₂ led to higher expression of Bax and Bcl-2 than in neurons exposed to H₂O₂ alone. Analysis of Bcl-2/Bax ratio as ‘survival index’ showed that both pretreatment of γT3 and αT followed by H₂O₂ increase the ‘survival index’ of Bcl-2/Bax ratio compared to H₂O₂-treated cells, while treatment of γT3 alone decrease the ratio compared to unchanged Bcl2/Bax ratio of similar treatment with αT alone. Similar treatment of γT3 decreased p53 expression and activates p38 MAPK phosphorylation, whereas αT did not alter its expression compared to H₂O₂-treated cells. Treating neurons with only γT3 or αT increased the expression of Bax, Bcl-2, p53, and p38 MAPK compared to control with γT3 exerting stronger expression for proteins involved than αT. In conclusion, low doses of γT3 and αT confer neuroprotection to H₂O₂-treated neurons via their antioxidant mechanism but γT3 has stronger pro-apoptosis tendency than αT by activating molecules involved in the neuronal apoptotic pathway in the absence of H₂O₂.     

Proteome alteration of U251 human astrocytoma cell after inhibiting retinoic acid synthesis

Retinoic acid (Ra) is crucial for the patterning and neuronal differentiation in the central nervous system (CNS). Ra deficiency in animals disrupts the motor activities and memory abilities. The molecular mechanisms underlying these behavior abnormalities remain largely unknown. In the current study, we treated the astrocytoma cells with citral, an inhibitor of Ra synthesis. We analyzed the differences in the protein concentrations between the treated and untreated astrocytoma cells by two-dimensional gel electrophoresis (2-DE), Imagemaster software, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In total, 39 of 46 altered protein spots with significant mascot scores were identified representing 36 proteins, that were involved in significantly altered glutamate metabolism, lipid metabolism, mitochrondrial function, and oxidative stress response by Ingenuity Pathway Analysis (IPA). Altered 3-phosphoglycerate dehydrogenase (PHGDH) was also observed in western blot. These data provide some clues for explaining the behavioral changes caused by Ra deficiency, and support the hypothesis that Ra signaling is associated with some symptoms of neurodegenerative disorders and schizophrenia.     

Evidence that TGFA influences risk to cleft lip with/without cleft palate through unconventional genetic mechanisms

This study examined the association between markers in transforming growth factor alpha (TGFA) and isolated, non-syndromic cleft lip with/without palate (CL/P) using a case–parent trio design, considering parent-of-origin effects. We also tested for gene–environmental interaction with common maternal exposures, and for gene–gene interaction using markers in TGFA and another recognized causal gene, IRF6. CL/P case–parent trios from four populations (76 from Maryland, 146 from Taiwan, 35 from Singapore, and 40 from Korea) were genotyped for 17 single nucleotide polymorphisms (SNPs) in TGFA. The transmission disequilibrium test was used to test individual SNPs, and the parent-of-origin likelihood ratio test (PO-LRT) was used to assess parent-of-origin effects. We also screened for possible gene–environment interaction using PBAT, and tested for gene–gene interaction using conditional logistic regression models. When all trios were combined, four SNPs showed significant excess maternal transmission, two of which gave significant PO-LRT values [rs3821261: P = 0.004 and OR(imprinting) = 4.17; and rs3771475: P = 0.027 and OR(imprinting) = 2.44]. Haplotype analysis of these two SNPS also supported excess maternal transmission. We saw intriguing but suggestive evidence of G × E interaction for several SNPs in TGFA when either individual SNPs or haplotypes of adjacent SNPs were considered. Thus, TGFA appears to influence risk of CL/P through unconventional means with an apparent parent-of-origin effect (excess maternal transmission) and possible interaction with maternal exposures.