ALTERNATIVE HOSTS OF TRICHOGRAMMA DENDROLIMI MATSUMURA IN DIFFERENT HABITATS (HYMENOPTERA: TRICHOGRAMMATIDAE)

Abstract  This paper deals with alternative hosts of an egg parasitoid. Trichogramma dendrolimi Matsumura in three habitats: mixed forest, pure stand and sparse wood. The experiment was conducted in Liuyan County which is located in the eastern part of Hunan Province. The results suggested that there are 103 species of alternative Lepidopteran hosts for T. dendrolimi . There were two critical periods throughout the year when there were no eggs of Dendrolimus punctatus Walker and few eggs of alternative hosts available for ovipsition by the parasitoids.     

Isolation and characterization of polymorphic microsatellite loci in a traditional Chinese medicinal plant, Schisandra sphenanthera

Schisandra sphenanthera (Schisandraceae) is a traditional Chinese medicinal plant. In this study, nine polymorphic microsatellite loci were developed and characterized for the species. A genomic DNA enrichment protocol was used to isolate microsatellite loci and polymorphism was explored using 36 individuals sampled from a natural population. The observed number of alleles ranged from 2 to 10 with an average of 5.2. Expected and observed heterozygosity ranged from 0.30 to 0.82 and 0.33 to 0.97, respectively. These microsatellites have been directly applied to both population and conservation genetic studies of S. sphenanthera.     

Down-regulation of lncRNA MEG3 promotes hypoxia-induced human pulmonary artery smooth muscle cell proliferation and migration via repressing PTEN by sponging miR-21

Hypoxia-induced pulmonary hypertension is a life-threatening disease arising from a progressive increase in pulmonary vascular resistance, irreversible pulmonary vascular remodeling and resulting in right ventricular failure. Recent studies suggested that pulmonary artery smooth muscle cell proliferation and migration played an important role in the pathogenesis of hypoxia-induced pulmonary hypertension. However, the mechanisms of hypoxia-induced pulmonary hypertension are complicated and largely unclear. In this study, we discovered that lncRNA MEG3 was down-regulated in human pulmonary artery smooth muscle cell in hypoxia, and inhibition of MEG3 promoted the cell proliferation and cell migration in both normal and hypoxia condition. Further study demonstrated that MEG3 exerted its function via regulation of miR-21 expression in both normal and hypoxia condition. In addition, we displayed the modulation of PTEN by miR-21 and their role in hypoxia. Ultimately, our study illustrated that MEG3 exerts its role via miR-21/PTEN axis in human pulmonary artery smooth muscle cell under both normal and hypoxia conditions.     

Genetic diversity and population differentiation of chestnut blight fungus, Cryphonectria parasitica, in China as revealed by RAPD

Seventeen Cryphonectria parasitica populations sampled from six regions in China were investigated using RAPD. Across all 169 isolates from the 17 populations evaluated, 52 of the 71 markers (73%) were polymorphic, total genetic diversity (h) was 0.1463, and Shannon’s index was 0.2312. Diversity within populations accounted for 74% of total genetic diversity, and genetic differentiation among populations was 0.26 (G _ST = 0.26). Gene flow was 1.4 among the populations; higher gene flow was found among populations within regions and among regions [N _m (G _SR) = 2.8 and N _m (G _RT) = 3.5]. The unweighted pair group mean analysis (UPGMA) dendrogram revealed two distinct clusters: the northern China group and the southern China group. The spatial autocorrelation analysis revealed that the variation at most loci was randomly distributed and lacked spatial structure, but several loci and closer distances were spatially structured. Human activity and habitat could also be important factors affecting genetic structure among C. parasitica populations in China. Genetic diversity was highest in Southwest China, descending in an orderly fashion to Northeast China. This pattern indicated that Southwest China might be the center of origin of C. parasitica in China. The present study provides useful information for understanding the origin and spread of chestnut blight fungus in China and valuable data for formulating relevant strategies for controlling the disease in China.     

A single-vector EYFP reporter gene assay for G protein-coupled receptors

We here present an improved and simplified assay to study signal transduction of the G_s class of G protein-coupled receptors (GPCRs). The assay is based on a single plasmid combining the genes for any G_s protein-coupled GPCR and the cAMP response element-related expression of enhanced yellow fluorescent protein. On transfection, stable human embryonic kidney 293 (HEK293) cell lines presented high assay sensitivity and an unprecedented signal-to-noise ratio of up to 300, even in the absence of trichostatin A. The robustness of the assay was demonstrated through the cloning of reporter gene cell lines with melanocortin 4 receptor (MC4R), the human type I pituitary adenylate cyclase-activating polypeptide receptor (hPAC1), and the two vasoactive intestinal peptide receptors (VPAC1 and VPAC2).     

不同生境中马尾松毛虫赤眼蜂中间寄主研究(英文)

本文讨论了马毛松毛虫赤眼蜂在混交林、纯林及疏残林三种不同生态环境条件下的中间寄主。试验是在湖南省东部的浏阳县进行。研究结果表明松毛虫赤眼蜂共有103种中间寄主;一年中有两个危险期,在危险期内只有少量的中间寄主存在。     

Competitive intra- and extracellular nutrient sensing by the transporter homologue Ssy1p

Recent studies of Saccharomyces cerevisiae revealed sensors that detect extracellular amino acids (Ssy1p) or glucose (Snf3p and Rgt2p) and are evolutionarily related to the transporters of these nutrients. An intriguing question is whether the evolutionary transformation of transporters into nontransporting sensors reflects a homeostatic capability of transporter-like sensors that could not be easily attained by other types of sensors. We previously found SSY1 mutants with an increased basal level of signaling and increased apparent affinity to sensed extracellular amino acids. On this basis, we propose and test a general model for transporter- like sensors in which occupation of a single, central ligand binding site increases the activation energy needed for the conformational shift between an outward-facing, signaling conformation and an inward-facing, nonsignaling conformation. As predicted, intracellular leucine accumulation competitively inhibits sensing of extracellular amino acids. Thus, a single sensor allows the cell to respond to changes in nutrient availability through detection of the relative concentrations of intra- and extracellular ligand.     

北京市自然保护地生态效益及其影响因素

自然保护地是生物多样性富集区域,发挥着水源涵养、防风固沙等重要的生态效益。北京市共5类79处自然保护地,是首都重要生态屏障,但自然因素和人为干扰对自然保护地生态效益有着重要影响。核算了北京自然保护地的5种典型的生态效益,使用单因素方差分析比较了不同类型自然保护地生态效益的差异,并基于冗余分析法探究了2种自然因素(年均气温和年降水量)和4种人为因素(人口密度、建设用地比例、耕地比例和道路密度)对生态效益的影响。结果表明：(1)北京自然保护地总体生态效益：北京自然保护地生境质量高,生境质量指数均值高达0.88;其它4项可价值化的生态效益中,水源涵养价值最大,固碳价值最低。(2)各类自然保护地之间生态效益比较：除生境质量外,其它4个生态效益之和,自然保护区和森林公园显著高于其它3类自然保护地;湿地公园的生境质量显著低于其它4类保护地,而这4类保护地之间生境质量并无显著差异;从水源涵养的生态效益来看,风景名胜区和地质公园显著低于其它3类自然保护地。(3)人为干扰因素(影响水平为38.92%)对生态效益的影响程度远高于自然因素(影响水平为16.63%);防风固沙、水土保持和固碳效益主要受人为干扰...