Mapping of the Glycoprotein 330 (Gp330) Gene to Mouse Chromosome 2

Glycoprotein 330 (Gp330) is a member of the low-density lipoprotein receptor gene family that is expressed in the kidney. We have mapped the Gp330 gene to mouse chromosome 2, 4.5 cM proximal to Acra, in an interspecific backcross of (C57BL/6J × Mus spretus) F1 × C57BL/6J.     

硝化抑制剂DCD、 DMPP对褐土氮总矿化速率和硝化速率的影响

采用15N库稀释-原位培养法研究了硝化抑制剂DCD、DMPP对华北盐碱性褐土氮总矿化速率和硝化速率的影响.试验在山西省运城市种植玉米的盐碱性土壤上进行,设单施尿素、尿素+DCD、尿素+DMPP 3个处理.结果表明:施肥后2周,DCD、DMPP分别使氮总矿化速率和氮总硝化速率减少了25.5％、7.3％和60.3％、59.1％,DCD对氮总矿化速率的影响显著高于DMPP,两者对氮总硝化速率的影响无显著差异;而在施肥后7周,不同硝化抑制剂对氮总硝化速率的影响存在差异.施肥后2周,3个处理的土壤氮总矿化速率和硝化速率分别是施肥前的7.2 ～10.0倍和5.5 ～21.5倍;NH4+和NO3-消耗速率分别是施肥前的9.1 ～12.2倍和5.1 ～8.4倍,这是由氮肥对土壤的激发效应所致.硝化抑制剂使氮肥更多地以NH4+形式保持在土壤中,减少了NO3-的积累.土壤氮总矿化速率和总硝化速率受硝化抑制剂的抑制是N2O减排的主要原因.     

Diversity of telomere palindromic sequences and replication genes among Streptomyces linear plasmids

Streptomyces sp. linear plasmids and linear chromosomes usually contain conserved terminal palindromic sequences bound by the conserved telomeric proteins Tap and Tp, encoded by the tap and tpg genes, respectively, as well as plasmid loci required for DNA replication in circular mode when the telomeres are deleted. These consist of iterons and an adjacent rep gene. By using PCR, we found that 8 of 17 newly detected linear plasmids in Streptomyces strains lack typical telomeric tap and tpg sequences. Instead, two novel telomeres in plasmids pRL1 and pRL2 from the eight strains and one conserved telomere in pFRL1 from the other strains were identified, while multiple short palindromes were also found in the plasmids. The complete nucleotide sequence of pRL2 revealed a gene encoding a protein containing two domains, resembling Tap of Streptomyces and a helicase of Thiobacillus, and an adjacent gene encoding a protein similar to Tpg of Streptomyces and a portion of the telomere terminal protein pTP of adenoviruses. No typical iterons-rep loci were found in the three plasmids. These results indicate an unexpected diversity of telomere palindromic sequences and replication genes among Streptomyces linear plasmids.     

Investigation of Repeat Client Drop-Out and Re-Enrolment Cycles in Fourteen Methadone Maintenance Treatment Clinics in Guangdong,China

ObjectiveClient adherence is vital for effective methadone maintenance treatment (MMT). This study explores the pattern and associated factors of client adherence, drop-out and re-enrolment in the Chinese MMT programme over the period of 2006–2013.MethodsThis retrospective study was conducted in 14 MMT clinics in Guangdong Province, China. We employed Kaplan-Meier survival analysis to estimate the rates of drop-out and re-enrolment of MMT clients and multivariate Cox regression to identify associated factors.ResultsAmong 1,512 study participants, 79% have experienced ‘drop-out’ during the 7-year study period. However, 82% ‘dropped-out’ clients resumed treatment at a later time. Low education level (junior high or below versus otherwise, HR = 1.21, 1.05–1.40), low methadone dosage in the first treatment episode (<50 ml versus ≥50 ml, HR = 1.84, 1.64–2.06) and higher proportion of positive urine test (≥50% versus<50%, HR = 3.72, 3.30–4.20) during the first treatment episode were strong predictors of subsequent drop-outs of the participants. Among the ‘dropped-out’ clients, being female (HR = 1.40, 1.23–1.60), being married (HR = 1.19, 1.09–1.30), and having a higher proportion of positive urine tests in the first treatment episode (≥50% versus<50%, HR = 1.35, 1.20–1.51) had greater likelihood of subsequent re-enrolment in MMT. Clients receiving lower methadone dosage (first treatment episode <50 ml versus ≥50 ml, HR = 1.12, 1.03–1.23; the last intake before drop-out <50 ml versus ≥50 ml, HR = 1.16, 1.04–1.30) were also more likely to re-enrol.ConclusionPersistent cycling in-and-out of clients in MMT programmes is common. Insufficient dosage and higher proportion of positive urine samples in the first treatment episode are the key determinants for subsequent client drop-out and re-enrolment. Interventions should target clients in their early stage of treatment to improve retention in the long term.     

陕西汉阴发现朱鹮新分布

中国朱鹮就地保护和易地保护取得的成果使朱鹮分布区的扩大成为可能。2013年6月3日,在陕西汉阴县龙垭镇凤柳村(32°58′N,108°31′E,海拔526 m)发现一对朱鹮(H12♀和B747♂)营巢繁殖,成功出飞3只幼鸟。2014年1月12日,我们又在该地的青泥河畔发现8只朱鹮的越冬觅食群体。其中包括上述繁殖配对及其3只后代、1只来自洋县野生种群的个体(J41)以及2只无法识别身份的个体。同年5月该繁殖配对成功出飞幼鸟4只。自2011年之后,宁陕朱鹮再引入种群的个体与洋县野生个体形成配对,说明两个种群之间存在基因交流。汉阴朱鹮新分布的发现表明,陕西宁陕朱鹮再引入项目的实施增加了朱鹮野生种群(源种群)向秦岭东部地区扩散的速度,还将有利于朱鹮再引入种群(卫星种群)的建立。     

Responses to ocean acidification and diurnal temperature variation in a commercially farmed seaweed,Pyropia haitanensis (Rhodophyta)

To investigate carbon and nitrogen metabolism in Pyropia haitanensis in response to the combined conditions of ocean acidification and diurnal temperature variation, maricultured thalli were tested in acidified culture under different temperature treatments. The results showed a combined effect of ocean acidification and diurnal temperature difference on the C and N metabolism and growth of P. haitanensis. In acidifed culture, algal growth, maximum photosynthetic rate, nitrate reductase (NR) activity, amino acid (AA) content and AA score (AAS) were more significantly enhanced in seaweed under diurnal temperature variation than in seaweed at constant temperature. In acidified seawater, soluble carbohydrates in P. haitanensis increased due to greater dissolved inorganic carbon (DIC), whereas soluble proteins decreased. Under the diurnal temperature treatment, higher temperature during the light period enhanced accumulation of algal photosynthates, whereas lower temperature in the dark period reduced energy consumption, resulting in enhanced algal growth, AA content and AAS. We concluded that suitable diurnal temperature difference would be conducive to C fixation and N assimilation under ocean acidification. However, excessively high temperatures would depress algal photosynthesis and increase energy consumption, thereby exerting a negative effect on algal growth.     

Molecular cloning and expression analysis of RrNHX1 and RrVHA-c genes related to salt tolerance in wild Rosa rugosa

Salt stress is one important factor influencing the growth and development of plants, and salt tolerance of plants is a result of combined action of multiple genes and mechanisms. Rosa rugosa is not only an important ornamental plant, but also the natural aromatic plant of high value. Wild R. rugosa which is naturally distributed on the coast and islands of China has a good salt tolerance due to the special living environment. Here, the vacuolar Na⁺/H⁺ reverse transporter gene (NHX1) and the vacuolar H⁺-ATPase subunit C gene (VHA-c) closely related to plant salt tolerance were isolated from wild R. rugosa, and the expression patterns in R. rugosa leaves of the two genes under NaCl stress were determined by real-time quantitative fluorescence PCR. The results showed that the RrNHX1 protein is a constitutive Na⁺/H⁺ reverse transporter, the expression of the RrNHX1 gene first increased and then decreased with the increasing salt concentration, and had a time-controlled effect. The RrVHA-c gene is suggestive of the housekeeping feature, its expression pattern showed a similar variation trend with the RrNHX1 gene under the stress of different concentrations of NaCl, and its temporal expression level under 200 mM NaCl stress presented bimodal change. These findings indicated that RrNHX1 and RrVHA-c genes are closely associated with the salt tolerance trait of wild R. rugosa.     

Synonymous Codon Usage Bias in Plant Mitochondrial Genes Is Associated with Intron Number and Mirrors Species Evolution

Synonymous codon usage bias (SCUB) is a common event that a non-uniform usage of codons often occurs in nearly all organisms. We previously found that SCUB is correlated with both intron number and exon position in the plant nuclear genome but not in the plastid genome; SCUB in both nuclear and plastid genome can mirror the evolutionary specialization. However, how about the rules in the mitochondrial genome has not been addressed. Here, we present an analysis of SCUB in the mitochondrial genome, based on 24 plant species ranging from algae to land plants. The frequencies of NNA and NNT (A- and T-ending codons) are higher than those of NNG and NNC, with the strongest preference in bryophytes and the weakest in land plants, suggesting an association between SCUB and plant evolution. The preference for NNA and NNT is more evident in genes harboring a greater number of introns in land plants, but the bias to NNA and NNT exhibits even among exons. The pattern of SCUB in the mitochondrial genome differs in some respects to that present in both the nuclear and plastid genomes.     

昆虫抗菌肽及其基因工程研究进展

昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽,具有广谱的抗菌、抗病毒、抑制肿瘤的生物活性,具有很高的应用潜力。本文主要介绍昆虫抗菌肽的类型、生理活性、基因的克隆与表达及转基因工程研究进展。 Insect Antibacterial Peptides and Its Progress in Advance on Genetic Engineering GONG Xia,YUE Guo-wei,SHI Yong-hui Laboratory for Animal Nutrition Research,College of Food Science,Southern Yangtze University,Wuxi 214036,China Abstract:Insect antibacterial peptides produced are kinds of bioactive peptides in hameolymph hen insect has been immunized.These peptides have the wide range of antibacterial,antiviral spectrum and inhibiting growth of tumor cell.The types of antibacterial peptides and its physiological activities,cloning and expression of the genes and transgenetic research are summarized.Its application on medicine and gene engineering are prospected. Key words：insect antibacterial peptides; physiological activity; gene     

细菌(Pseudomonas maltophilia)之绒毛膜促性腺激素(hCG)结合物质之研究

 细菌(Pseudomonas moltophilia)与hCG及LH有特异的亲和力,实验发现,细菌之生长曲线与hCG结合活性成平行关系,96小时达高峰,细菌之培养液中含有可溶性结合蛋白,该蛋白经硫酸铵沉淀(80％饱和度)、Sephadex G-100柱层析、DEAE-纤维素柱0.5mol/L NaCl梯度洗脱,再过Sepharose CL-AB柱,收集之活性部分经SDS电泳测得其分子量为70,000,凝胶层析测Stokes radius为41A,Schiff氏染色未见着色带。