Agrobacterium-mediated production of transgenic rice plants expressing a chimeric α-amylase promoter/β-glucuronidase gene

We have successfully transferred and expressed a reporter gene driven by an -amylase promoter in a japonica type of rice (Oryza sativa L. cv. Tainung 62) using the Agrobacterium-mediated gene transfer system. Immature rice embryos (10–12 days after anthesis) were infected with an Agrobacterium strain carrying a plasmid containing chimeric genes of -glucuronidase (uidA) and neomycin phosphotransferase (nptII). Co-incubation of potato suspension culture (PSC) with the Agrobacterium inoculum significantly improved the transformation efficiency of rice. The uidA and nptII genes, which are under the control of promoters of a rice -amylase gene (Amy8) and Agrobacterium nopaline synthase gene (nos), respectively, were both expressed in G418-resistant calli and transgenic plants. Integration of foreign genes into the genomes of transgenic plants was confirmed by Southern blot analysis. Histochemical localization of GUS activity in one transgenic plant (R0) revealed that the rice -amylase promoter functions in all cell types of the mature leaves, stems, sheaths and roots, but not in the very young leaves. This transgenic plant grew more slowly and produced less seeds than the wild-type plant, but its R1 and R2 progenies grew normally and produced as much seeds as the wild-type plant. Inheritance of foreign genes to the progenies was also confirmed by Southern blot analysis. These data demonstrate successful gene transfer and sexual inheritance of the chimeric genes.     

西藏21种真菌的血凝活性测定

选用了21种野生真菌,分别以PBS(磷酸缓冲液)浸提,浸提液进行兔红血球血凝活性测定,结果显示:冬虫夏草(Cordyceps sinensis)、蜜环菌(Armillariella mellea)、翘鳞肉齿菌(Sarcodon imbricatus)等不能使兔红血球凝集,显阴性;其余真菌均能使兔红血球凝集,其中以棱柄白马鞍菌(Helvella crispa)和美味牛肝菌(Boletus edulis)效价最高26;盘状马鞍菌(Helvella pezizoids)次之25;其余的均为20～23.取PBS浸提效价较高的6种样品棱柄白马鞍菌、盘状马鞍菌、真姬离褶伞(Lyophyllum shimeji)、红菇腊伞(Hygrophorus russula)、美味牛肝菌、离褶伞(Lyophyllum)等分别用Tris、NaAcetate(乙酸钠)、Glycin(甘氨酸)等不同pH缓冲液浸提,浸提液进行兔红血球血凝活性测定,结果显示:显弱酸性或弱碱性的缓冲液浸提时,浸提液对兔红血球血凝活性效价高于中性缓冲液,浸提真菌样品时最好使用弱酸或弱碱性缓冲液.     

Protective Effect of the Silkworm Protein 30Kc6 on Human Vascular Endothelial Cells Damaged by Oxidized Low Density Lipoprotein (Ox-LDL)

Although the 30K family proteins are important anti-apoptotic molecules in silkworm hemolymph, the underlying mechanism remains to be investigated. This is especially the case in human vascular endothelial cells (HUVECs). In this study, a 30K protein, 30Kc6, was successfully expressed and purified using the Bac-to-Bac baculovirus expression system in silkworm cells. Furthermore, the 30Kc6 expressed in Escherichia coli was used to generate a polyclonal antibody. Western blot analysis revealed that the antibody could react specifically with the purified 30Kc6 expressed in silkworm cells. The In vitro cell apoptosis model of HUVEC that was induced by oxidized low density lipoprotein (Ox-LDL) and in vivo atherosclerosis rabbit model were constructed and were employed to analyze the protective effects of the silkworm protein 30Kc6 on these models. The results demonstrated that the silkworm protein 30Kc6 significantly enhanced the cell viability in HUVEC cells treated with Ox-LDL, decreased the degree of DNA fragmentation and markedly reduced the level of 8-isoprostane. This could be indicative of the silkworm protein 30Kc6 antagonizing the Ox-LDL-induced cell apoptosis by inhibiting the intracellular reactive oxygen species (ROS) generation. Furthermore, Ox-LDL activated the cell mitogen activated protein kinases (MAPK), especially JNK and p38. As demonstrated with Western analysis, 30Kc6 inhibited Ox-LDL-induced cell apoptosis in HUVEC cells by preventing the MAPK signaling pathways. In vivo data have demonstrated that oral feeding of the silkworm protein 30Kc6 dramatically improved the conditions of the atherosclerotic rabbits by decreasing serum levels of total triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). Furthermore, 30Kc6 alleviated the extent of lesions in aorta and liver in the atherosclerotic rabbits. These data are not only helpful in understanding the anti-apoptotic mechanism of the 30K family proteins, but also provide important information on prevention and treatment of human cardiovascular diseases.     

Combined Use of Systematic Conservation Planning,Species Distribution Modelling,and Connectivity Analysis Reveals Severe Conservation Gaps in a Megadiverse Country (Peru)

Conservation planning is crucial for megadiverse countries where biodiversity is coupled with incomplete reserve systems and limited resources to invest in conservation. Using Peru as an example of a megadiverse country, we asked whether the national system of protected areas satisfies biodiversity conservation needs. Further, to complement the existing reserve system, we identified and prioritized potential conservation areas using a combination of species distribution modeling, conservation planning and connectivity analysis. Based on a set of 2,869 species, including mammals, birds, amphibians, reptiles, butterflies, and plants, we used species distribution models to represent species'' geographic ranges to reduce the effect of biased sampling and partial knowledge about species'' distributions. A site-selection algorithm then searched for efficient and complementary proposals, based on the above distributions, for a more representative system of protection. Finally, we incorporated connectivity among areas in an innovative post-hoc analysis to prioritize those areas maximizing connectivity within the system. Our results highlight severe conservation gaps in the Coastal and Andean regions, and we propose several areas, which are not currently covered by the existing network of protected areas. Our approach helps to find areas that contribute to creating a more representative, connected and efficient network.     

A second‐generation genetic linkage map for bighead carp (Aristichthys nobilis) based on microsatellite markers

Bighead carp (Aristichthys nobilis) is an important aquaculture fish worldwide. Genetic linkage maps for the species were previously reported, but map resolution remained to be improved. In this study, a second‐generation genetic linkage map was constructed for bighead carp through a pseudo‐testcross strategy using interspecific hybrids between bighead carp and silver carp. Of the 754 microsatellites genotyped in two interspecific mapping families (with 77 progenies for each family), 659 markers were assigned to 24 linkage groups, which were equal to the chromosome numbers of the haploid genome. The consensus map spanned 1917.3 cM covering 92.8% of the estimated bighead carp genome with an average marker interval of 2.9 cM. The length of linkage groups ranged from 52.2 to 133.5 cM with an average of 79.9 cM. The number of markers per linkage group varied from 11 to 55 with an average of 27.5 per linkage group. Normality tests on interval distances of the map showed a non‐normal marker distribution; however, significant correlation was found between the length of linkage group and the number of markers below the 0.01 significance level (two‐tailed). The length of the female map was 1.12 times that of the male map, and the average recombination ratio of female to male was 1.10:1. Visual inspection showed that distorted markers gathered in some linkage groups and in certain regions of the male and female maps. This well‐defined genetic linkage map will provide a basic framework for further genome mapping of quantitative traits, comparative mapping and marker‐assisted breeding in bighead carp.     

生物体衰老与复制衰老--体内与体外研究

体外连续培养的细胞在有人数的细胞分裂后,更新换代合成ＤＮＡ及分裂的能力,最后导致增殖能力的丧失,但基本代谢过程仍能维持,这种现象称为复制衰老。本文讨论了复制衰老现象存在的普遍性,描述了衰老细胞伯特征,对复制衰老和生物体衰老之间的联系进行了重点分析。现有的研究虽然还不完全,但都提示复制衰老是生物体衰老在细胞水平上的反映,并充分肯定了复制衰老是一个较好的研究机体衰老的模型。     

罗布泊地区第四纪环境演化

新疆罗后干涸湖盆中的Ｋ１钻孔揭示,１００、２ｍ的沉积剖面共有９２个宙积层,划归１６同积旋回,包括了早更新世以来的各时期沉积。据划分的１５个孢粉组这及古地磁、１４＾Ｃ、岩石地层资料综合分析,早更新世该区曾发育森林－草原植被,早更民末,强烈的构造运动保留我下更充变形,上覆的中更统与下更新统间呈不整合接触。中更新世,荒漠和荒漠草原交替出现,地层中有大量膏质泥岩和石膏。晚更新世以来,在干旱气候的控制之下,     

A Modified Valley Restrained Monte Carlo Method to Efficiently Search the Low Energy Structures of Peptides

Abstract

A new Monte Carlo sampling scheme, namely the Modified Valley Restrained Monte Carlo procedure, is used to obtain the global energy minimum conformations for polypeptides, such as Met-enkephalin and Melittin. For each peptide, we found close agreement with previous results from both theoretical and experimental studies. The simple idea for controlling the step size according to the Valley Function, provides useful suggestions in searching the global energy minimum structures, and furthermore helps solve the multiple minima problem.     

Disentangling Two QTL on Porcine Chromosome 12 for Backfat Fatty Acid Composition

A previous study allowed the identification of two QTL regions at positions 11–34 cM (QTL1) and 68–76 cM (QTL2) on porcine chromosome SSC12 affecting several backfat fatty acids in an Iberian x Landrace F2 intercross. In the current study, different approaches were performed in order to better delimit the quoted QTL regions and analyze candidate genes. A new chromosome scan, using 81 SNPs selected from the Porcine 60KBeadChip and six previously genotyped microsatellites have refined the QTL positions. Three new functional candidate genes (ACOX1, ACLY, and SREBF1) have been characterized. Moreover, two putative promoters of porcine ACACA gene have also been investigated. New isoforms and 24 SNPs were detected in the four candidate genes, 19 of which were genotyped in the population. ACOX1 and ACLY SNPs failed to explain the effects of QTL1 on palmitic and gadoleic fatty acids. QTL2, affecting palmitoleic, stearic, and vaccenic fatty acids, maps close to the ACACA gene location. The most significant associations have been detected between one intronic (g.53840T > C) and one synonymous (c.5634T > C) ACACA SNPs and these fatty acids. Complementary analyses including ACACA gene expression quantification and association studies in other porcine genetic types do not support the expected causal effect of ACACA SNPs.     

Associations between Level and Change in Physical Function and Brain Volumes

Background

Higher levels of fitness or physical function are positively associated with cognitive outcomes but the potential underlying mechanisms via brain structure are still to be elucidated in detail. We examined associations between brain structure and physical function (contemporaneous and change over the previous three years) in community-dwelling older adults.

Methodology/Principal Findings

Participants from the Lothian Birth Cohort 1936 (N=694) underwent brain MRI at age 73 years to assess intracranial volume, and the volumes of total brain tissue, ventricles, grey matter, normal-appearing white matter, and white matter lesions. At ages 70 and 73, physical function was assessed by 6-meter walk, grip strength, and forced expiratory volume. A summary ‘physical function factor’ was derived from the individual measures using principal components analysis. Performance on each individual physical function measure declined across the three year interval (p<0.001). Higher level of physical function at ages 70 and 73 was associated with larger total brain tissue and white matter volumes, and smaller ventricular and white matter lesion volumes (standardized β ranged in magnitude from 0.07 to 0.17, p<0.001 to 0.034). Decline in physical function from age 70 to 73 was associated with smaller white matter volume (0.08, p<0.01, though not after correction for multiple testing), but not with any other brain volumetric measurements.

Conclusions/Significance

Physical function was related to brain volumes in community-dwelling older adults: declining physical function was associated with less white matter tissue. Further study is required to explore the detailed mechanisms through which physical function might influence brain structure, and vice versa.