卵翅哑蟋和纹股秦蟋雄性的记述（直翅目：蟋蟀总科）

对卵翅哑蟋Goniogryllus ovalatus Chen et Zheng和纹股秦蟋Qingryllus stri-ofemorus Chen et Zheng的雄性进行首次记述,标本保存于陕西师范大学动物研究所。     

Retracted: MicroRNA-34a inhibit hepatocellular carcinoma progression by repressing hexokinase-1

Hepatocellular carcinoma (HCC) is known as a frequent type of primary cancer in the liver, and it is the third-most common cause of cancer-related death all over the world. However, the molecular mechanism in the progression of HCC is still unclear. The current study was designed to investigate the expression and function of microRNA-34a (miR-34a) in HCC. In HCC tissues and cells, the expression levels of miR-34a were analyzed by quantitative real-time polymerase chain reaction. The association between the level of miR-34a and hexokinase (HK)-1 was also investigated via luciferase reporter assay. Cell viability and proliferation were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry. To assess whether miR-34a can limit tumor growth in vivo, animal models and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were used for examining the role of miR-34a on the development of HCC and cell apoptosis. The expression level of miR-34a was reduced in HCC samples and cells. The expression of miR-34a was associated with the viability and proliferation capacity of HCC cells, and miR-34a could inhibit HCC cells proliferation by inhibiting HK1. In the mouse model of HCC, volumes and weight of the tumors were significantly decreased by transfection with miR-34a mimic compared with the control group. Furthermore, miR-34a mimics could induce apoptosis in a greater proportion of cells compared with the control group. Taken together, the data may provide some novel insights into the molecular mechanism of miR-34a and HK1 in the progression of HCC. Thus, miR-34a/HK1 axis might be a novel promising therapeutic target for treating HCC.     

Nucleotide diversity and molecular evolution of the WAG-2 gene in common wheat (Triticum aestivum L) and its relatives

In this work, we examined the genetic diversity and evolution of the WAG-2 gene based on new WAG-2 alleles isolated from wheat and its relatives. Only single nucleotide polymorphisms (SNP) and no insertions and deletions (indels) were found in exon sequences of WAG-2 from different species. More SNPs and indels occurred in introns than in exons. For exons, exons+introns and introns, the nucleotide polymorphism π decreased from diploid and tetraploid genotypes to hexaploid genotypes. This finding indicated that the diversity of WAG-2 in diploids was greater than in hexaploids because of the strong selection pressure on the latter. All dn/ds ratios were < 1.0, indicating that WAG-2 belongs to a conserved gene affected by negative selection. Thirty-nine of the 57 particular SNPs and eight of the 10 indels were detected in diploid species. The degree of divergence in intron length among WAG-2 clones and phylogenetic tree topology suggested the existence of three homoeologs in the A, B or D genome of common wheat. Wheat AG-like genes were divided into WAG-1 and WAG-2 clades. The latter clade contained WAG-2, OsMADS3 and ZMM2 genes, indicating functional homoeology among them.     

Mice with different susceptibility to Japanese encephalitis virus infection show selective neutralizing antibody response and myeloid cell infectivity

Background

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes public health problems in Asian countries. Only a limited number of JEV-infected individuals show symptoms and develop severe encephalitis, indicating host-dependent susceptibilities.

Methodology/Principal Findings

C3H/HeN and DBA/2 mice, which exhibit different mortalities when infected by intraperitoneal inoculation with JEV, were used as experimental models to compare viral pathogenesis and host responses. One hundred infectious virus particles killed 95% of C3H/HeN mice whereas only 40% of DBA/2 mice died. JEV RNA was detected with similar low levels in peripheral lymphoid organs and in the sera of both mouse strains. High levels of viral and cytokine RNA were observed simultaneously in the brains of C3H/HeN and DBA/2 mice starting on days 6 and 9 post-infection, respectively. The kinetics of the cytokines in sera correlated with the viral replication in the brain. Significantly earlier and higher titers of neutralizing antibodies were detected in the DBA/2 strain. Primary embryonic fibroblasts, bone marrow-derived dendritic cells and macrophages from the two mouse strains were cultured. Fibroblasts displayed similar JEV replication abilities, whereas DBA/2-derived myeloid antigen-presenting cells had lower viral infectivity and production compared to the C3H/HeN–derived cells.

Conclusions/Significance

Mice with different susceptibilities to JEV neuroinvasion did not show changes in viral tropism and host innate immune responses prior to viral entry into the central nervous system. However, early and high neutralizing antibody responses may be crucial for preventing viral neuroinvasion and host fatality. In addition, low permissiveness of myeloid dendritic cells and macrophages to JEV infection in vitro may be elements associated with late and decreased mouse neuroinvasion.     

Review of the genus Apotrechus in China (Orthoptera,Gryllacrididae, Gryllacridinae)

In the present paper, the genus Apotrechus Brunner-Wattenwyl, 1888 is revised. Two new species from China are described and illustrated: Apotrechus quadratus sp. n. and Apotrechus truncatolobus sp. n.. A new key and the distributional data are given.     

Formation of forest gaps accelerates C,N and P release from foliar litter during 4 years of decomposition in an alpine forest

High-latitude boreal and arctic surface/inland waters contain sizeable reservoirs of dissolved organic matter (DOM) and trace elements (TE), which are subject to seasonal freezing. Specifically, shallow ponds and lakes in the permafrost zone often freeze solid, which can lead to transformations in the colloidal and dissolved fractions of DOM and TE. Here, we present results from experimental freeze-thaw cycles using iron (Fe)- and DOM-rich water from thaw ponds situated in Stordalen and Storflaket palsa mires in northern Sweden. After ten cycles of freezing, 85% of Fe and 25% of dissolved organic carbon (DOC) were removed from solution in circumneutral fen water (pH 6.9) but a much smaller removal of Fe and DOC (< 7%) was found in acidic bog water (pH 3.6). This removal pattern was consistent with initial supersaturation of fen water with respect to Fe hydroxide and a lack of supersaturation with any secondary mineral phase in the bog water. There was a nearly two- to threefold increase in the low-molecular-weight (LMW) fraction of organic carbon (OC) and several TEs caused by the repeated freeze-thaw cycles. Future increases in the freeze-thaw frequency of surface waters with climate warming may remove up to 25% of DOC in circumneutral organic-rich waters. Furthermore, an increase of LMW OC may result in enhanced carbon dioxide losses from aquatic ecosystems since this fraction is potentially more susceptible to biodegradation.     

里氏木霉产纤维素酶研究进展

木质纤维素类生物质被认为是重要且可持续的可再生能源,其主要组成部分是纤维素.纤维素酶是一种能将纤维素分解为葡萄糖的复合酶,能有效地降解木质纤维素生物质.真菌、细菌、放线菌、酵母等多种微生物均可以产生纤维素酶,其中里氏木霉具有完整的纤维素酶系结构,常作为生物技术领域中一个重要菌株,广泛应用于纤维素酶的商业生产.介绍了纤维...     

实践教学在植物学课程教学中的探索

《植物学》是生物学科中一门重要的基础课程,该课程与实践教学联系紧密。从课堂教学、实验教学、野外实习、科研实践等4个方面阐述了实践教学在植物学课程教学中的几点体会,试图为植物学的教学提出一些建议,以期达到提高教学质量,培养综合性人才的目的。