湖北房县下寒武统西蒿坪段钉形骨片化石

本文对采自湖北房县三座庵剖面下寒武统西蒿坪段的钉形骨片(nail-shaped)化石进行了研究,系统厘定和描述了2属2种,分别为Parazhijinites guizhouensis和Cambroclavus angxianensis;其中以C.fangxianensis骨片化石最为丰富,由三种类型的骨片组成,它们可能...     

Association mapping for partial resistance to Phytophthora sojae in soybean (Glycine max (L.) Merr.)

Association mapping is a powerful high-resolution mapping tool for complex traits. The objective of this study was to identify QTLs for partial resistance to Phytophthora sojae. In this study, we evaluated a total of 214 soybean accessions by the hypocotyl inoculation method, and 175 were susceptible. The 175 susceptible accessions were then evaluated for P. sojae partial resistance using slant board assays. The 175 accessions were screened with 138 SSR markers that generated 730 SSR alleles. A subset of 495 SSR loci with minor allele frequency (MAF) ≥ 0.05 was used for association mapping by the Tassel general linear model (GLM) and mixed linear model (MLM) program. This soybean population could be divided into two subpopulations and no or weak relatedness was detected between pairwise accessions. Four SSR alleles, Satt634-133, Satt634-149, Sat_222-168 and Satt301-190, associated with partial resistance to P. sojae were detected by both GLM and MLM methods. Of these identified markers, one marker, Satt301, was located in regions where P. sojae resistance QTL have been previously mapped using linkage analysis. The identified markers will help to understand the genetic basis of partial resistance, and facilitate future marker-assistant selection aimed to improve resistance to P. sojae and reduce disease-related mortality in soybean.     

坝上地区农田及两种恢复生境中蜘蛛多样性与群落特征

蜘蛛是农田生态系统中重要的自然天敌,其生物多样性及群落特征直接决定了农田的害虫控制等生态系统服务功能质量。农田及其周边的恢复生境是蜘蛛重要的栖息地。本研究采用陷阱法,对河北省张家口市崇礼区871、1360、1635 m 3个海拔农田、自然恢复草地及人工修复林地的蜘蛛群落的物种组成、物种多样性和功能特征进行研究,分析不同恢复生境中蜘蛛群落特征。结果表明: 不同生境蜘蛛的物种多样性指数差异明显,人工修复林地蜘蛛的多度为124.3只,显著高于自然恢复草地(70.1)及农田(38.6)的蜘蛛多度;人工修复林地(16.3)与自然恢复草地(21.4)的物种丰富度没有显著差别,但均显著高于农田(8.9);人工修复林地(2.04)及自然恢复草地(2.05)的Shannon多样性指数差异不显著,且均显著高于农田(1.55)。3种生境的蜘蛛群落组成均具有显著差异;蜘蛛体长与蜘蛛捕猎类型呈正相关,大型蜘蛛倾向于通过捕猎获取食物;自然恢复草地与农田蜘蛛以游猎型为主,而人工修复林地倾向于拥有更多的结网型蜘蛛,高海拔地区的蜘蛛体积通常较小。自然恢复草地与人工修复林地均可以提升蜘蛛群落多样性,在区域生物多样性保护中起重要作用;不同生境蜘蛛群落组成出现了显著分化,即蜘蛛群落总体的功能特征发生改变和保留了部分生境特有种。2种恢复生境蜘蛛多样性指标优于农田生境,且2种恢复生境物种组成存在差异,均具有保护特有种的功能,研究结果对农田及区域尺度蜘蛛生物多样性保护与恢复具有指导意义。     

Infection with vaccinia favors the selection of hybridomas synthesizing autoantibodies against intermediate filaments, one of them cross-reacting with the virus hemagglutinin

Immunization of mice with lysates from infected cells and pure vaccinia virus generated hybridomas, a large fraction of which make autoantibodies binding to intermediate filaments (greater than IF) and vimentin. Antibodies that can be detected in preimmune mice as weakly binding to the cytoskeleton (greater than CS) are elevated in potency after immunization with either active or UV-inactivated pure vaccinia, suggesting that virus replication may not be obligatory for activation of greater than CS lymphocyte clones. Demonstration of a cross-reactivity of one IF monoclonal antibody with virally coded hemagglutinin, expressed at the surface, raises questions about the development of pathologic conditions associated with virus-mediated autoimmunity.     

小叶臭黄皮叶挥发油化学成分的研究

采用水蒸气蒸馏法提取小叶臭黄皮叶挥发油,运用毛细管气相色谱-质谱联用法对挥发油成分进行了分析,共分离出84个峰,鉴定了其中的66种成分,所鉴定成分占挥发油总量的94.52%.其主要化学成分为α-芹子烯(15.76%)、石竹烯(15.05%)、β-芹子烯(9.54%)、α-蒎烯(6.43%)和α-石竹烯(5.39%)等.     

Polymorphic microsatellite primers developed from DNA of the endangered Mekong giant catfish,Pangasianodon gigas (Chevey) and cross‐species amplification in three species of Pangasius

The critically endangered Pangasianodon gigas is endemic to the Mekong River. Despite its importance, little is known about its genetic diversity and conservation efforts are hampered. Ten polymorphic dinucleotide microsatellite primer pairs were developed from DNA of P. gigas. The analysis of 20 individuals from hatchery stocks using these primers resulted in two to six alleles/locus; H_O = 0.05–0.95; H_E = 0.05–0.81. All but one locus (Pg‐3) conformed to Hardy–Weinberg expectation. Eight, six and seven primer pairs were amplified with the DNA from Pangasianodon hypophthalmus, Pangasius larnaudii and Pangasius sanitwongsei, respectively. These markers will be useful for genetic monitoring of wild and hatchery stocks of these pangasiids.     

蟋蟀视觉系统的解剖结构与生理机能

蟋蟀视觉系统由单眼、复眼、视叶三部分组成。蟋蟀的单眼为背单眼,由角膜、角膜生成细胞、视网膜等组成,是提高昆虫复眼所感知的视觉刺激的兴奋水平部位;复眼是最主要的视觉器官,由角膜、晶锥、感杆束和网膜细胞、基膜组成,是光电转导和视觉级联反应的中心;视叶由神经节层、外髓和内髓组成,是视觉神经系统的中心。     

垂体瘤转化基因(PTTG1)可抵抗UV诱导的细胞凋亡作用

垂体瘤转化基因（PTTG1）在很多肿瘤中呈高水平表达.越来越多的研究表明,PTTG1与细胞增殖、细胞转化有关.但PTTG1在凋亡中的作用仍不清楚.通过在细胞中下调和过表达PTTG1,观察PTTG1在UV照射诱导凋亡中的作用.结果发现, RNAi-介导下调HeLa细胞PTTG1表达可增加对UV诱导凋亡的敏感性,而过表达PTTG1则降低对UV诱导凋亡的敏感性.此外,UV照射能降低PTTG1蛋白的表达水平,并且表现为明显的剂量和时间关系.这些研究结果显示,PTTG1在UV照射诱导的凋亡中发挥重要的抗凋亡作用.这为研究PTTG1在肿瘤发生、发展中的作用机制提供了新的实验证据.