Functional characterization of a new human Ad4BP/SF-1 variation, G146A

Ad4BP/SF-1 plays key roles at all levels of the hypothalamic-pituitary-steroidogenic organ axis and its functional disruption causes endocrine disorders of these organs. However, only three human subjects with Ad4BP/SF-1 mutations have been reported to date, suggesting limited clinical significance as a cause of inborn adrenal or sexual abnormalities. We report the first functional characterization of a new variation found in the hinge region of human Ad4BP/SF-1, G146A. Resulting from a single nucleotide shift (GGG-->GCG), G146A bears slightly diminished transactivation activity evidenced by both adrenal specific cyp11A promoter and ovary specific cyp19 promoter II. The variation does not affect protein expression or stability, exhibiting no dominant negative effect. G146A has a normal interaction pattern with standard co-regulators and subnuclear distribution pattern, and can be considered as a nonsynonymous single nucleotide polymorphism, since it occurs in normals and patients with adrenal diseases. In normal Japanese the allele C frequency is 8%, while in a preliminary population of patients with adrenal diseases it is elevated to 30%; suggesting the G146A variation might be of clinical importance.     

水分胁迫下臭柏（Sabina vulgaris Ant.）光合特性和色素组成的季节变化

在室内砾耕栽培条件下,通过培养液中加入PEG(Polyethylene glycol 分子量为6000)以调节溶液渗透势,设置对照、弱水分胁迫和强水分胁迫3种处理 (培养液渗透势分别为0.02,-0.1,-0.34 MPa), 从1997年开始对臭柏进行长期干旱胁迫模拟实验.2003年测定了臭柏叶片光合色素和光合特性的季节变化.结果表明:对照区气孔导度季节变化在5月和9月份形成了典型的双峰曲线.尽管对照区的气孔导度明显高于其他两个处理,但日光合量却低于弱水分胁迫区.3个处理Chl a/b的比值在11月至翌年3月的低温期内均升高,以强水分胁迫区的增幅最大,其它月份该比值在3个处理之间没有显著的差异.3个处理的叶绿素总量(Chl a+b)在生长季的5～9月份均有不同程度的上升,但其中以强水分胁迫区增幅最小.在11月至翌年3月的低温期,各处理均大幅提高叶黄素总量(V+A+Z)和热耗散色素比例(A+Z)/(V+A+Z) (V:紫黄质、A:单环氧玉米黄质、Z:玉米黄质);在5～7月份的生长高峰期,各处理则明显降低了叶黄素总量和热耗散色素比例.这种趋势在强水分胁迫区表现的更为显著.     

CO2浓度升高对不同品种水稻镉吸收和根形态的影响

为了探讨CO2浓度升高下不同水稻品种荣优398 (RY)和粤杂889(YZ)吸收重金属Cd差异性的原因,利用水培试验研究了不同浓度Cd处理下两种水稻吸收Cd的差异及根形态的变化特征.结果表明:低Cd处理(5、10、20 μmol·L-1)显著增加水稻生物量;当Cd浓度高于50 μmol·L-1时,Cd胁迫效果开始显现,水稻生物量减少.CO2浓度升高显著增加了水稻的生物量,增加了YZ茎Cd含量而降低了RY茎Cd含量.在5～200 μmol·L-1的Cd浓度下,CO2浓度升高增加了YZ活性根在总根长中的比例,降低了RY活性根的比例.CO2浓度升高下不同水稻品种根形态的变化是导致其对Cd吸收差异性的原因之一.     

PSMD: An extensive database for pan‐species microsatellite investigation and marker development

Microsatellites are widely distributed throughout nearly all genomes which have been extensively exploited as powerful genetic markers for diverse applications due to their high polymorphisms. Their length variations are involved in gene regulation and implicated in numerous genetic diseases even in cancers. Although much effort has been devoted in microsatellite database construction, the existing microsatellite databases still had some drawbacks, such as limited number of species, unfriendly export format, missing marker development, lack of compound microsatellites and absence of gene annotation, which seriously restricted researchers to perform downstream analysis. In order to overcome the above limitations, we developed PSMD (Pan‐Species Microsatellite Database, http://big.cdu.edu.cn/psmd/ ) as a web‐based database to facilitate researchers to easily identify microsatellites, exploit reliable molecular markers and compare microsatellite distribution pattern on genome‐wide scale. In current release, PSMD comprises 678,106,741 perfect microsatellites and 43,848,943 compound microsatellites from 18,408 organisms, which covered almost all species with available genomic data. In addition to interactive browse interface, PSMD also offers a flexible filter function for users to quickly gain desired microsatellites from large data sets. PSMD allows users to export GFF3 formatted file and CSV formatted statistical file for downstream analysis. We also implemented an online tool for analysing occurrence of microsatellites with user‐defined parameters. Furthermore, Primer3 was embedded to help users to design high‐quality primers with customizable settings. To our knowledge, PSMD is the most extensive resource which is likely to be adopted by scientists engaged in biological, medical, environmental and agricultural research.     

Overexpression of phosphoenolpyruvate carboxylase from Jatropha curcas increases fatty acid accumulation in Nicotiana tabacum

Jatropha curcas L. is an excellent biofuel crop, which displays a high efficiency of carbon absorption, and seed oil of Jatropha can be efficiently processed to produce high-quality biodiesel. Plant phosphoenolpyruvate carboxylases (PEPCs) play important roles not only in initial fixation of atmospheric CO₂ in C₄ and Crassulacean acid metabolism (CAM) plants, but also in fatty acid biosynthesis in seeds of oil plants by regulating carbon partitioning. Here, we identified JcPEPC1 from J. curcas L. by homology cloning, and alignment analysis of protein sequence revealed JcPEPC1 was a plant C₃-type PEPC, and shared high similarity to PEPC of castor oil plant Ricinus communis. We implemented detailed functional characterization of JcPEPC1 by expression analysis and transgenic tobacco. JcPEPC1 gene expressed in the leaves and seeds of J. curcas L., and remarkable increase of expression level was also detected at seed oil-accumulating stages. We overexpressed JcPEPC1 in tobacco, and showed the enzymatic activity of PEPC in transgenic plants was notably higher than wild type. Gas chromatography (GC) analysis elucidated the composition and total content of fatty acids were also altered. This study indicated JcPEPC1 played a fundamental role in fatty acid biosynthesis in Jatropha seeds. Our results proposed enhanced PEPC activity of Jatropha could improve biosynthesis of fatty acid, which implied critical functions in primary metabolism of non-photosynthetic PEPC.     

The pig genome project has plenty to squeal about

Significant progress on pig genetics and genomics research has been witnessed in recent years due to the integration of advanced molecular biology techniques, bioinformatics and computational biology, and the collaborative efforts of researchers in the swine genomics community. Progress on expanding the linkage map has slowed down, but the efforts have created a higher-resolution physical map integrating the clone map and BAC end sequence. The number of QTL mapped is still growing and most of the updated QTL mapping results are available through PigQTLdb. Additionally, expression studies using high-throughput microarrays and other gene expression techniques have made significant advancements. The number of identified non-coding RNAs is rapidly increasing and their exact regulatory functions are being explored. A publishable draft (build 10) of the swine genome sequence was available for the pig genomics community by the end of December 2010. Build 9 of the porcine genome is currently available with Ensembl annotation; manual annotation is ongoing. These drafts provide useful tools for such endeavors as comparative genomics and SNP scans for fine QTL mapping. A recent community-wide effort to create a 60K porcine SNP chip has greatly facilitated whole-genome association analyses, haplotype block construction and linkage disequilibrium mapping, which can contribute to whole-genome selection. The future 'systems biology' that integrates and optimizes the information from all research levels can enhance the pig community's understanding of the full complexity of the porcine genome. These recent technological advances and where they may lead are reviewed.     

Development of mechanistically based model for simulating soluble microbial products generation in an aerated/non-aerated SBR

Soluble microbial products (SMPs) are considered as the main organic components in wastewater treatment plant effluent from biological wastewater treatment systems. To investigate and explore SMP metabolism pathway for further treatment and control, two innovative mechanistically based activated sludge models were developed by extension of activated sludge model no.3 (ASM3). One was the model by combining SMP formation and degradation (ASM3-SMP model) processes with ASM3, and the other by combining both SMP and simultaneous substrate storage and growth (SSSG) mechanisms with ASM3 (SSSG-ASM3-SMP model). The detailed schematic modification and process supplements were introduced for comprehensively understanding all the mechanisms involved in the activated sludge process. The evaluations of these two models were demonstrated by a laboratory-scale sequencing batch reactor (SBR) operated under aerated/non-aerated conditions. The simulated and measured results indicated that SMP comprised about 83% of total soluble chemical oxygen demand (SCOD) in which biomass-associated products (BAPs) were predominant compared with utilization-associated products (UAPs). It also elucidated that there should be a minimum SMP value as the reactive time increases continuously and this conclusion could be used to optimize effluent SCOD in activated sludge processes. The comparative results among ASM3, ASM3-SMP and SSSG-ASM3-SMP models and the experimental measurements (SCOD, ammonia and nitrate nitrogen) showed clearly the best agreement with SSSG-ASM3-SMP simulation values (R = 0.993), strongly suggesting that both SMP formation and degradation and SSSG mechanisms are necessary in biologically activated sludge modeling for municipal wastewater treatment.     

Genetic and alkaloid analysis of Menispermum dauricum DC. by RAPD and HPLC

The aim of the present work was to determine whether dauricine could be used as a taxonomic marker for Menispermum dauricum DC., and to explore the correlation among RAPD, ecological markers and chemical markers. To this end, the chemical and genetic differences of 173 individual samples of M. dauricum from nine different sources were studied based on the relevant ecological factors including longitude, latitude, annual precipitation, mean temperature, annual accumulated temperature and mean sea level. The contents of dauricine in the sample rhizomes were assayed by HPLC with photodiode array detection. The leaves from the same sample were assayed using randomly amplified polymorphism DNA (RAPD). The genetic distances were then compared. Hierarchical cluster analysis and multiple linear stepwise regression analysis were used in the statistical analysis. The results indicated that the contents of dauricine were respectively correlated with the genetic distance (r = 1.000), longitude (r = 0.849), latitude (r = 0.861), annual precipitation (r = 0.903), mean temperature(r = 0.912), annual accumulated temperature (r = 0.919) and mean sea level (r = 0.925). It is concluded that the content of dauricine in M. dauricum is significantly correlated with genetic distance and ecological factors, and may be used as the taxonomic marker.     

温度对香蕉花蓟马发育和存活的影响

通过在人工气候箱内饲养香蕉花蓟马,测定了14、18、22、26℃和30℃5个温度下香蕉花蓟马不同虫态的发育历期,分析了温度与香蕉花蓟马发育速率的关系,计算了其发育起点温度、有效积温及存活率。结果表明:香蕉花蓟马各虫态的发育历期随温度的升高而缩短,发育速率和温度之间有很大的相关性;香蕉花蓟马卵、一龄若虫、二龄若虫、预蛹、蛹及世代的发育起点温度分别为8.26、10.56、7.92、9.17、9.53、8.69℃,世代的有效积温为153.81d·℃。26℃下香蕉花蓟马的世代存活率最高,为63.16%;30℃下的存活率最低,为46.34%。