Hemoglobin Portland 1: a new human hemoglobin unique in structure

A new hemoglobin (Hb), Portland 1, has been found in a newborn infant having multiple congenital anomalies and complex autosomal chromosomal mosaicism. The new hemoglobin has a unique tetrameric structure (molecular weight, 66,000) composed of two pairs of different types of chains, neither of which is alpha, gamma(2)x(2). The x-chain of Hb Portland 1 may be a new type of hemoglobin chain, but the available evidence suggests that it may be identical with the epsilon chain. We suggest that Hb Portland 1 is an embryonic hemoglobin that persisted until after birth in relatively large amounts in this patient.     

Cleavage of Arabidopsis PBS1 by a bacterial type III effector

Plant disease-resistance (R) proteins are thought to function as receptors for ligands produced directly or indirectly by pathogen avirulence (Avr) proteins. The biochemical functions of most Avr proteins are unknown, and the mechanisms by which they activate R proteins have not been determined. In Arabidopsis, resistance to Pseudomonas syringae strains expressing AvrPphB requires RPS5, a member of the class of R proteins that have a predicted nucleotide-binding site and leucine-rich repeats, and PBS1, a protein kinase. AvrPphB was found to proteolytically cleave PBS1, and this cleavage was required for RPS5-mediated resistance, which indicates that AvrPphB is detected indirectly via its enzymatic activity.     

昆虫病原线虫Oscheius myriophila 共生细菌菌株B1 的分离与鉴定

从昆虫病原线虫(Oscheius myriophila)华农种群HN体内分离得到1株共生细菌B1。该菌株在NA培养基上形成的菌落为圆形,白色,表面光滑,不透明,隆起,边缘整齐;革兰氏阴性,短杆状,单鞭毛,有荧光。Biolog检测结果显示B1为沙雷氏菌(Serratia sp.);用引物27F/1492R进行PCR扩增,得到B1的16S rDNA扩增产物大小为1 445 bp。Blast搜寻和比对结果表明,该菌株16S rDNA序列与所选的17个嗜线虫沙雷氏菌(S.nematodiphila)的相似度达97%~100%,并以高置信度(99)与这17个嗜线虫沙雷氏菌种群及4个粘质沙雷氏菌(S.marcescens)种群聚于1个单支系中。综合形态和16S r DNA序列特征以及Biolog检测结果,将共生细菌B1鉴定为嗜线虫沙雷氏菌(Serratia nematodiphila)。     

Ultraviolet irradiation transforms C3H10T1/2 cells to a unique, suppressible phenotype

Transformation of C3H10T1/2 cells by exposure to ultraviolet (UV) irradiation followed by tetradecanoyl phorbol acetate (TPA) has been used as a model of two-stage carcinogenesis. However, cells cloned from UV-TPA-induced foci (UV-TDTx cells) had a unique phenotype. Cloned UV-TDTx cells appeared transformed in pure culture but were unable to form foci when cocultured with C3H10T1/2 cells. However, in the presence of TPA, UV-TDTx cells form foci in mixed culture with C3H10T1/2 cells. This phenotype was the only one observed for UV-TPA transformants. These data suggest that communal suppression of cell division is a discrete phenomenon that must be overcome as one step in the multistage process of transformation, and this protocol permits the routine isolation of transformed cells responsive to density-dependent growth suppression.     

斑点叉尾鮰致病菌株的鉴定及特性

菌株IP0004是从患病斑点叉尾鮰Ictalurus punctatus肝脏中分离出的一株致病菌。经形态学观察、生理生化特性分析和16S rRNA基因序列测定分析对其进行分类鉴定,确定其为类志贺邻单胞菌Plesiomonasshigelloides。该菌为革兰氏阴性杆菌,极生单鞭毛,无芽孢,有荚膜;发酵葡萄糖、麦芽糖、海藻糖产酸,鸟氨酸脱羧酶、赖氨酸脱羧酶、精氨酸双水解酶、β-半乳糖甙酶、α-半乳糖甙酶为阳性;其生长盐度为0~25,pH值为5~10,最适生长温度为37℃。菌株IP0004 16S rRNA基因部分序列与类志贺邻单胞菌16SrRNA相应基因序列的同源性均大于99%,构建的系统进化树显示该菌株与类志贺邻单胞菌聚为一类。菌株IP0004的细胞毒性外膜蛋白COMP（cytotoxic outer-membrane protein）基因与类志贺邻单胞菌的COMP基因序列相似性大于99.9%,说明该菌株为类志贺邻单胞菌,具有COMP基因,有一定的致病力。药物敏感试验结果表明,菌株IP0004对头孢曲松、头孢拉定、头孢唑林、氧氟沙星敏感,而对新生霉素、利复平、复方新诺明不敏感。     

斑点叉尾鮰致病菌株的鉴定及特性

菌株IP0004是从患病斑点叉尾鮰Ictalurus punctatus肝脏中分离出的一株致病菌。经形态学观察、生理生化特性分析和16S rRNA基因序列测定分析对其进行分类鉴定,确定其为类志贺邻单胞菌Plesiomonasshigelloides。该菌为革兰氏阴性杆菌,极生单鞭毛,无芽孢,有荚膜;发酵葡萄糖、麦芽糖、海藻糖产酸,鸟氨酸脱羧酶、赖氨酸脱羧酶、精氨酸双水解酶、β-半乳糖甙酶、α-半乳糖甙酶为阳性;其生长盐度为0²5,pH值为525,pH值为5¹0,最适生长温度为37℃。菌株IP0004 16S rRNA基因部分序列与类志贺邻单胞菌16SrRNA相应基因序列的同源性均大于99%,构建的系统进化树显示该菌株与类志贺邻单胞菌聚为一类。菌株IP0004的细胞毒性外膜蛋白COMP(cytotoxic outer-membrane protein)基因与类志贺邻单胞菌的COMP基因序列相似性大于99.9%,说明该菌株为类志贺邻单胞菌,具有COMP基因,有一定的致病力。药物敏感试验结果表明,菌株IP0004对头孢曲松、头孢拉定、头孢唑林、氧氟沙星敏感,而对新生霉素、利复平、复方新诺明不敏感。     

The function of the cranial crest and jaws of a unique pterosaur from the Early Cretaceous of Brazil

The discovery of a previously undescribed pterosaur, Thalassodromeus sethi, yields information on the function of cranial crests and the feeding strategy developed by these extinct flying reptiles. The material consists of a large skull (length: 1420 millimeters, including the crest) with a huge bony crest that was well irrigated by blood vessels and may have been used for regulation of its body temperature. The rostrum consists of two bladelike laminae, the arrangement of which is analogous to the condition found in the bird Rynchops, which skims over the water to catch food, indicating that T. sethi also may have been a skimmer.     

Secretion of a bacterial cellulase by yeast

Gene fusions were constructed between a yeast expression plasmid and a Cellulomonas fimi DNA fragment encoding an endo-1,4-beta-D-glucanase or carboxymethylcellulase. Yeast transformed with the recombinant plasmids secreted carboxymethylcellulase activity. Secretion of active enzyme was greatly increased when the leader of a secreted yeast protein, the Kl toxin, was inserted immediately upstream of and in frame with the bacterial cellulase sequence. This is the first step in constructing a functional cellulase complex in Saccharomyces cerevisiae. It also provides an excellent system for the detailed examination of the determinants of protein secretion because of the ease with which secreted cellulase can be detected.     

Cat scratch disease: a bacterial infection

Histopathologic examination of lymph nodes from 39 patients with clinical and pathological criteria for cat scratch disease revealed delicate pleomorphic Gram-negative bacilli in 34 of the 39 nodes. They were within the walls of capillaries in or near areas of follicular hyperplasia and within microabscesses. They were best seen with the Warthin-Starry silver impregnation stain. Organisms in lymph node sections exposed to convalescent serum from three patients and to immunoperoxidase stained equally well with all three samples. The organisms did not react with hyperimmune sera to Legionella pneumophila nor to several species of Rickettsia. These bacilli appear to be the causative agents of cat scratch disease.     

来源于疣粒野生稻高抗白叶枯病水稻新种质遗传连锁图谱的构建(英文)

Y73是一个疣粒野生稻和栽培稻不对称体细胞杂交的后代株系,它兼具了野生稻高抗白叶枯病的特性和栽培稻优异的农艺性状。本研究以Y73和易感白叶枯病的水稻品种IR24为亲本创制了重组自交系群体,并利用该群体构建了Y73特异的遗传连锁图谱。该图谱包含155个简单重复序列(simple sequence re-peats,SSR)标记和56个序列标签位点(sequence-tagged site,STS)标记,覆盖约1 540.0 cM的水稻基因组区域,平均图距为7.89 cM。该遗传图谱的构建为水稻白叶枯病抗性和其他农艺性状相关的数量性状位点(quantitative trait loci,QTLs)的定位、重要基因的分离和分子标记辅助育种提供了基础。     

四川省某奶牛场犊牛呼吸道疾病的细菌性病原qPCR检测

为了解四川省某规模化奶牛养殖场犊牛呼吸道疾病(bovine respiratory disease,BRD)的病原情况,进而制定防治措施,本研究通过TaqMan荧光定量PCR方法对2019—2020年75份有呼吸道疾病症状的犊牛鼻腔棉拭子和10份其他样品进行常见细菌性病原检测.结果显示,多杀性巴氏杆菌(Pm)、睡眠嗜血...     

九里香内生细菌HBS-1的鉴定及其对芒果采后病害的防效

通过组织表面消毒法对九里香内生菌进行分离,以芒果炭疽病菌(Colletotrichum gloeosporioides Penz)和芒果蒂腐病菌(Botryodiplodia theobromae Pat)为靶标菌对获得菌株进行皿内拮抗能力筛选,利用浸果法测定菌株发酵滤液对芒果采后病害的防治效果,结合菌株形态、生理生化特征及16S rDNA序列鉴定菌株。结果从九里香中分离到28株内生菌,其中有8株真菌、9株细菌对2种病原菌均有拮抗活性,以HBS-1抑菌活性最好,对芒果炭疽病菌及芒果蒂腐病菌抑制率分别为42.0%和50.0%;菌株HBS-1发酵滤液能明显降低芒果采后病害的发病率,10倍稀释液的防效优于化学药剂特克多800倍液,50倍稀释液的防效与化学药剂特克多800倍液相当;经鉴定,内生菌HBS-1为芽孢杆菌属枯草芽孢杆菌(Bacillus subtilis)。     

条石鲷烂尾白浊症病原菌的分离鉴定及系统发育分析

从患烂尾白浊症的条石鲷肾脏和肝脏等病变组织分离出致病力较强的菌株TP0701,人工感染实验证实该菌株为条石鲷的病原菌。对该细菌进行了形态、生理生化特性测定和16S rRNA分子鉴定,测定16SrRNA基因序列,分析相关细菌相应序列的同源性,构建了系统进化树。结果表明菌株TP0701与恶臭假单胞菌(Pseudomonas putida)的亲缘关系最近,具有98.1%的同源性。结合该菌株的生理生化特性,可鉴定菌株TP0701为恶臭假单胞菌。     

条石鲷烂尾白浊症病原菌的分离鉴定及系统发育分析

从患烂尾白浊症的条石鲷肾脏和肝脏等病变组织分离出致病力较强的菌株TP0701,人工感染实验证实该菌株为条石鲷的病原菌。对该细菌进行了形态、生理生化特性测定和16S rRNA分子鉴定,测定16SrRNA基因序列,分析相关细菌相应序列的同源性,构建了系统进化树。结果表明菌株TP0701与恶臭假单胞菌(Pseudomonas putida)的亲缘关系最近,具有98.1%的同源性。结合该菌株的生理生化特性,可鉴定菌株TP0701为恶臭假单胞菌。     

Wetting patterns and bacterial distributions in different soils from a surface point source applying effluents with varying Escherichia coli concentrations

Understanding bacterial transportation in unsaturated soil is helpful for reducing and avoiding pathogenic contamination that may be induced by irrigation with reclaimed waste water and for developing better irrigation management practices. Experiments were conducted to study the transport of a typical bacterium, Escherichia coli(E. coli), in a sandy and a sandy loam soil under different application rates and input concentrations. A 30° wedge-shaped plexiglass container was used to represent one twelfth of the complete cylinder in the experiments. The apparent cylindrical application rate varied from 1.05 to 5.76 L h–1 and the input concentration of E. coli from magnitude of 102 to 107 colony-forming unit(CFU) m L–1. F or a given volume of water applied, an increase in application rate resulted in an increase in the wetted radius and a decrease in the wetted depth. In the sandy loam soil, the water spread out in a circular-arc shaped saturated zone on the surface, and the ultimate saturated entry radius increased with the application rate. An increasing application rate of water suspended bacteria allowed a more rapid transport of bacteria, thus accelerating E. coli transport rate and resulting in a larger distributed volume of E. coli for both soil types. For the sandy soil, more than 70% of the E. coli that was detected within the entire wetted volume concentrated in the range of 10 cm from the point source, and the concentration of E. coli decreased greatly as the distance from the point source increased. More than 98% of the E. coli was detected in a range of 5 cm around the saturated wetted zone for the sandy loam soil. For both soil types tested, an extremely high concentration of E. coli was observed in the proximity of the point source, and the peak value increased with an increased input concentration. In principle, using an emitter with relative lower application rate would be effective to restrict E. coli transport. To reduce bacterial concentration in the sewage effluent during wastewater treatment is important to decrease the risk of soil contamination caused by irrigation with sewage effluent.     

一株产脂肪酶细菌的分离、筛选和鉴定

【目的】从自然界筛选出脂肪酶高产菌株,鉴定其种属并对其酶学性质进行研究.【方法】从白银市不同地点油污染河流和土壤中采集样品,利用维多利亚蓝培养基与中性红油脂培养基进行初筛,改进铜皂-分光光度计法测定酶活力进行复筛,再结合形态观察、生理生化鉴定和16SrDNA序列分析进行菌种鉴定,并对脂肪酶的酶学性质进行研究.【结果】分离筛选出一株产脂肪酶的细菌BY-8,鉴定为粪产碱杆菌(Alcaligenes faecalis).该菌株所产脂肪酶在40℃和pH 7.0的条件下酶活力为3.64U/mL.酶学性质研究结果表明,产生的脂肪酶最适作用温度和pH分别为35℃和7.0,Mg~(2+)和Ca~(2+)对脂肪酶活性有明显地促进作用,而Cu~(2+)和Zn~(2+)对酶活性有抑制作用,EDTA和SDS可使脂肪酶失去活力.【结论】菌株BY-8所产脂肪酶的酶活力一般,但酶学性质稳定,是一种中性脂肪酶.     

小麦类CTR1基因的克隆和特性分析

 【目的】克隆小麦类CTR1基因（TaCTR1）,研究其在各种胁迫条件下的表达、亚细胞定位和过量表达TaCTR1对转基因烟草耐盐性的影响。【方法】利用RACE结合RT-PCR技术克隆TaCTR1,利用半定量RT-PCR研究TaCTR1在各种非胁迫及ABA处理条件下的表达,通过烟草转化研究过量表达TaCTR1对转基因植株耐盐性的影响。【结果】TaCTR1全长2 635 bp,编码759个氨基酸,在其羧基端有一个非常保守的丝氨酸/苏氨酸蛋白激酶结构域,该结构域含有ATP结合位点和一个钙调素结合位点;TaCTR1与其它植物中CTR1的氨基酸序列同源性较高。TaCTR1的表达受NaCl和干旱胁迫的诱导,当用30μmol?L-1 ABA对小麦幼苗进行处理时,TaCTR1的表达受到抑制,当将小麦幼苗转移至无ABA的Hoagland培养液时,TaCTR1的表达又逐渐升高。利用洋葱表皮细胞进行瞬时表达显示TaCTR1可能定位于细胞质膜。过量表达TaCTR1的转基因烟草植株耐盐性下降。【结论】 TaCTR1是小麦中克隆的第一个CTR1基因,TaCTR1:GFP可能定位于细胞质膜,过量表达TaCTR1的烟草植株耐盐性下降说明TaCTR1是植物耐盐信号传导途径的负调控因子。     

Cloning and Characterization of a Putative CTR1 Gene from Wheat

CTR1 is a key negative regulator in ethylene signal transduction. A salt-induced CTR1 like gene （TaCTR1） was cloned from wheat, its expression under abiotic stresses, subcellular localization and the effect of overexpression of TaCTR1 on salt tolerance in tobacco was studied. A putative CTR1 gene was cloned and characterized from wheat via rapid amplification of cDNA ends （RACE） and RT-PCR. TaCTR1 expression under stresses was analyzed using semi-quantitative RT-PCR and the effect of overexpression of TaCTR1 on salt tolerance was conducted in tobacco. The full-length cDNA of TaCTR1 is 2 635 bp which codes for a polypeptide of 759 amino acids. There is a conserved serine/threonine protein kinase domain at the carboxyl terminus containing an ATP-binding site. Southern blot analysis revealed that TaCTR1 consisted of a gene family in wheat. The amino acid homologies of CTR1 among different organisms share higher similarities. Expression analysis revealed that TaCTR1 was induced by NaC1 and drought stress but inhibited by ABA treatment. Transient expression of TaCTR1-GFP in the onion epidermal cells indicated that TaCTR1 was probably targeted to the plasma membrane. Overexpression of TaCTR1 decreased salt tolerance in transgenic tobacco （Nicotiana tabacum L.） plants compared with the control. To our knowledge, TaCTR1 is the first CTR1 gene cloned in wheat and may be involved in various abiotic stresses. Overexpression of TaCTR1 decreased the salt tolerance in tobacco suggested that TaCTR1 may act as a negative regulator of salt stress in plants.     

1B Specific LMW-GS Primers Cloned a 1D Located Gene from Wheat Cultivar Xiaoyan 22

In the present study, one unique low-molecular-weight glutenin subunit （LMW-GS） gene. LMWXY22-2 （GenBank no. FJ028810）, was isolated from wheat cultivar Xiaoyan 22 （Triticum aestivum L.） by a pair of genomic specific PCR primers for 1B chromosome. Sequence analysis revealed that LMWXY22-2 was composed of 1 364 bp nucleotides, including a 317 bp promotion region and a 1 047 bp coding region which could be translated into a mature protein of 349 amino acids. In spite of a few minor mutations, the sequence of 5＇ untranslated region （UTR）, the coding region, the deduced N- and Cterminus comparisons indicated that LMWXY22-2 belonged to the reported subunits of LMW-m type and type lII group 5, respectively. Inner gene markers for 1D chromosome together with the phylogenetic analysis revealed that this gene was classified into Glu-D3, which was not in agreement with the I B locus-specific primers for LMW genes completely.