亚硝基胍诱变选育林肯霉素高产菌株

以林肯链霉菌９４７－８（Ｓｔｒｅｐｔｏｍｙｃｅｓｌｉｎｃｏｌｎｅｎｓｉｓ９４７－８）为出发菌株（产林肯霉素９４０γ／ｍｌ）。采用孢子热处理方法处理出发菌株孢子,得到变异株９４７－８ｓ,产林肯霉素１０８０γ／ｍｌ。对９４７－８ｓ菌株进行ＮＴＧ诱变处理,得变异株９４７－８ｘ,产林肯霉素为１２１８γ／ｍｌ,且生产能力稳定。     

杨,榆混交型林带生长调解试验研究

我国三北地区大面积农田防护林网主要为杨树林网,树种单一,容易造成病虫害蔓延。但由多树种组成的混交林网由于树种生长速度不同,造成树木群体生长参差不齐,而导致某些树木受压抑而不能正常生长甚至死亡,从而降低了林带的防护效益。为改变这一现状并建立起一整套混交...     

中国柱角水虻属二新种(双翅目,水虻科)(英文)

记述我国柱角水虻属2新种,即黄跗柱角水虻Beris flava sp.nov.,舟曲柱角水虻B.zhouquensis sp.nov.。模式标本保存在中国农业大学昆虫博物馆和中国科学院动物研究所。1黄跗柱角水虻,新种Beris flavasp.nov.(图1～3)新种与端褐柱角水虻B.fuscipes Meigen近似,但复眼的毛短而稀疏,生殖背板无背侧突,生殖突长钩状。正模♂,宁夏径源龙潭,1880m,2008-07-05,刘经贤。副模1♂,同正模。2舟曲柱角水虻,新种Beris zhouquensis sp.nov.(图4～6)新种与指突柱角水虻B.digitata Li,Zhanget Yang近似,但跗节全黑色,生殖突基部无突起。正模♂,甘肃舟曲沙滩林场,2400m,1999-07-17,王洪建。副模1♂,同正模,1999-07-16,姚建采。     

Difference in 24-Hour Urine Composition between Diabetic and Non-Diabetic Adults without Nephrolithiasis

Background

Diabetic patients are more likely to develop kidney stones than the general population. The underlying mechanisms for this disparity remain to be elucidated. Little is known about the relationship between urine composition and diabetes mellitus in non-stone-forming individuals. We sought to examine the differences in the 24-hour (24-h) urine composition between diabetic and non-diabetic adults who were not stone formers.

Methods

A convenience sample of 538 individuals without a history of nephrolithiasis, gout, hyperparathyroidism, or gastroenteric diseases participated in this study. The 24-h urine profiles of 115 diabetic adults were compared with those of 423 non-diabetic adults. Diabetes was defined by self-reported physician diagnosis or medication use. All participants were non-stone formers confirmed by urinary tract ultrasonography. Participants provided a fasting blood sample and a single 24-h urine collection for stone risk analysis. Student’s t-test was used to compare mean urinary values. Linear regression models were adjusted for age, gender, body mass index, hypertension, fasting serum glucose, serum total cholesterol, estimated creatinine clearance rate and urinary factors.

Results

Univariable analysis showed that the diabetic participants had significantly higher 24-h urine volumes and lower urine calcium and magnesium excretions than non-diabetic participants (all P < 0.05). After multivariate adjustment, no significant differences in 24-h urine composition were observed between diabetic and non-diabetic participants except for a slightly increased 24-h urine volume in diabetic participants (all P > 0.05). The main limitation of this study is that the convenience samples and self-reported data may have been sources of bias.

Conclusion

Our data showed that there were no differences in 24-h urine composition between diabetic and non-diabetic adults who are not stone formers. The reason for it might be the improved glycemic control in diabetic individuals in our study. Therefore, a tighter glycemic control might reduce stone formation in diabetic adults.     

Angelman Syndrome Protein Ube3a Regulates Synaptic Growth and Endocytosis by Inhibiting BMP Signaling in Drosophila

Altered expression of the E3 ubiquitin ligase UBE3A, which is involved in protein degradation through the proteasome-mediated pathway, is associated with neurodevelopmental and behavioral defects observed in Angelman syndrome (AS) and autism. However, little is known about the neuronal function of UBE3A and the pathogenesis of UBE3A-associated disorders. To understand the in vivo function of UBE3A in the nervous system, we generated multiple mutations of ube3a, the Drosophila ortholog of UBE3A. We found a significantly increased number of total boutons and satellite boutons in conjunction with compromised endocytosis in the neuromuscular junctions (NMJs) of ube3a mutants compared to the wild type. Genetic and biochemical analysis showed upregulation of bone morphogenetic protein (BMP) signaling in the nervous system of ube3a mutants. An immunochemical study revealed a specific increase in the protein level of Thickveins (Tkv), a type I BMP receptor, but not other BMP receptors Wishful thinking (Wit) and Saxophone (Sax), in ube3a mutants. Ube3a was associated with and specifically ubiquitinated lysine 227 within the cytoplasmic tail of Tkv, and promoted its proteasomal degradation in Schneider 2 cells. Negative regulation of Tkv by Ube3a was conserved in mammalian cells. These results reveal a critical role for Ube3a in regulating NMJ synapse development by repressing BMP signaling. This study sheds new light onto the neuronal functions of UBE3A and provides novel perspectives for understanding the pathogenesis of UBE3A-associated disorders.     

Human metapneumovirus Induces Reorganization of the Actin Cytoskeleton for Direct Cell-to-Cell Spread

Paramyxovirus spread generally involves assembly of individual viral particles which then infect target cells. We show that infection of human bronchial airway cells with human metapneumovirus (HMPV), a recently identified paramyxovirus which causes significant respiratory disease, results in formation of intercellular extensions and extensive networks of branched cell-associated filaments. Formation of these structures is dependent on actin, but not microtubule, polymerization. Interestingly, using a co-culture assay we show that conditions which block regular infection by HMPV particles, including addition of neutralizing antibodies or removal of cell surface heparan sulfate, did not prevent viral spread from infected to new target cells. In contrast, inhibition of actin polymerization or alterations to Rho GTPase signaling pathways significantly decreased cell-to-cell spread. Furthermore, viral proteins and viral RNA were detected in intercellular extensions, suggesting direct transfer of viral genetic material to new target cells. While roles for paramyxovirus matrix and fusion proteins in membrane deformation have been previously demonstrated, we show that the HMPV phosphoprotein extensively co-localized with actin and induced formation of cellular extensions when transiently expressed, supporting a new model in which a paramyxovirus phosphoprotein is a key player in assembly and spread. Our results reveal a novel mechanism for HMPV direct cell-to-cell spread and provide insights into dissemination of respiratory viruses.     

Differential Expression of microRNAs and their Regulatory Networks in Skin Tissue of Liaoning Cashmere Goat during Hair Follicle Cycles

MicroRNAs (miRNAs) are endogenous small noncoding RNA molecules that negatively regulate gene expression. Herein, we investigated a selective number of miRNAs for their expression in skin tissue of Liaoning Cashmere goat during hair follicle cycles, and their intracellular regulatory networks were constructed based on bioinformatics analysis. The relative expression of six miRNAs (mir-103-3p, -15b-5p, 17-5p, -200b, -25-3p, and -30c-5p) at anagen phase is significantly higher than that at catagen and/or telogen phases. In comparison to anagen, the relative expression of seven miRNAs (mir-148a-3p, -199a-3p, -199a-5p, -24-3p, -30a-5p, -30e-5p, and -29a-3p) was revealed to be significantly up-regulated at catagen and/or telogen stages. The network analyses of miRNAs indicated those miRNAs investigated might be directly or indirectly involved in several signaling pathways through their target genes. These results provided a foundation for further insight into the roles of these miRNAs in skin tissue of Liaoning Cashmere goat during hair follicle cycles.     

Interacting proteins and differences in nuclear transport reveal specific functions for the NAP1 family proteins in plants

Nucleosome assembly protein 1 (NAP1) is conserved from yeast to human and facilitates the in vitro assembly of nucleosomes as a histone chaperone. Inconsistent with their proposed function in the nucleus, however, many NAP1 proteins had been reported to localize in the cytoplasm. We investigated the subcellular localization of tobacco (Nicotiana tabacum) and rice (Oryza sativa) NAP1 family proteins first by identification of interacting partners and by direct examination of the localization of green fluorescent protein-tagged proteins. Through treatment of tobacco cells with leptomycin B and mutagenesis of nuclear export signal, we demonstrated that Nicta;NAP1;1 and Orysa;NAP1;1 shuttle between the cytoplasm and the nucleus. Together with the demonstration that tobacco NAP1 proteins bind histone H2A and H2B, our results support the current model and provide additional evidence that function of NAP1 as histone chaperones appears to be conserved in plants. In addition, we show that tobacco NAP1 proteins interact with tubulin and the mitotic cyclin Nicta;CYCB1;1, suggesting a role for NAP1 in microtubule dynamics. Interestingly, in spite of their high homology with the above NAP1 proteins, the other three tobacco proteins and Orysa;NAP1;2 did not show nucleocytoplasmic shuttling and were localized only in the cytoplasm. Moreover, Orysa;NAP1;3 that lacks a typical nuclear localization signal sequence was localized in both the cytoplasm and the nucleus. Finally, we show that only Orysa;NAP1;3 could be phosphorylated by casein kinase 2alpha in vitro. However, this phosphorylation was not responsible for nuclear import of Orysa;NAP1;3 as being demonstrated through mutagenesis studies. Together, our results provide an important step toward elucidating the molecular mechanism of function of the NAP1 family proteins in plants.