自然界斜纹夜蛾核型多角体病毒的基因型多态性

【目的】从基因组序列角度进一步揭示自然界斜纹夜蛾核型多角体病毒（Spodoptera litura nucleopolyhedrovirus, SpltNPV）的基因型多态性。【方法】病毒克隆A5, F1, X3 和 X15分别以活体克隆法分离自SpltNPV埃及株、 日本福冈株和日本小笠原株。根据SpltNPV基因组全序列（GenBank登录号: AF325155）和海灰翅夜蛾核型多角体病毒（S. littoralis NPV, SpliNPV）部分基因序列（GenBank登录号: X99377, X99376 和X98924）设计引物, PCR扩增获得A5, F1, X3 和 X15的多角体蛋白（polyhedrin, polh）基因和ORF18~ORF23序列。【结果】根据多角体蛋白基因序列, X3和X15属于SpltNPV型, 而A5和F1属于SpliNPV型。将A5, F1, X3 和 X15的ORF18~ORF23与SpltNPV和SpliNPV相应的基因序列进行同源性比较。结果发现, F1与SpliNPV以及X3与SpltNPV的核苷酸序列相似性高, 但X3的ORF20在172~558 nt处缺失387 bp。尽管依据多角体蛋白基因序列X15属于SpltNPV型, 但对于ORF18~ORF23序列, X15与SpliNPV的相似性高于与SpltNPV的相似性。同样, A5属于SpliNPV型, ORF18~ORF20与SpliNPV相应的核苷酸序列相似性高, 但ORF21与SpltNPV相应的核苷酸序列一致性为100%, 特别是ORF22, SpltNPV的特有序列出现在A5的基因组中, 而且与SpltNPV的ORF22一致性为100%; 反过来, ORF23又与SpliNPV相应的核苷酸序列相似性高。【结论】所有这些都表明, SpltNPV在自然界不仅存在基因型多态性, 而且即使属于同一基因型, 它们的基因组序列也有显著差异。可利用SpltNPV在自然界的这种异质性筛选适宜防治斜纹夜蛾幼虫的株系。     

黄土高原半干旱偏旱区草粮轮作田土壤水分恢复效应模拟

采用实地调查和EPIC模型相结合的方法,模拟研究了黄土高原半干旱偏旱区不同草粮轮作模式的土壤水分恢复效应.结果表明：多年生苜蓿地和苜蓿翻耕后种植粮食作物农田0～10 m土层土壤湿度调查值与模拟值间的相关系数均超过0.9（P<0.01）,相对均方根误差在0.05～0.16,相对误差均低于10%;模拟与实测的土壤湿度剖面分布变化趋势一致.在黄土高原半干旱偏旱区,苜蓿地深层土壤干层恢复难度较大,在种植苜蓿期间应避免8～10 m土层土壤湿度降到5.7%以下.苜蓿地适宜种植年限为4～6 a,最长不应超过8 a.苜蓿翻耕后适宜采用马铃薯→马铃薯→春小麦轮作模式进行土壤水分恢复,32～33 a后可以再次种植苜蓿.     

对6个国外城市街道规划设计导则的解析——“如何规划步行友好的城市街道开放空间？”

本文将“如何通过街道规划设计,营建步行友好的城市开放空间环境,提高居民生活质量？”作为研究视角,抽取了6个国外城市街道规划设计导则中与“如何规划设计步行友好的城市开放空间？”密切相关的内容,根据相关导则编制的逻辑将内容进行提炼、归纳和重组。针对中国通过改善街道步行环境建设高品质城市的诉求以及相关导则中缺少对使用者需求关注的现状,提出了将需求调查纳入规划规定环节、从环境特征角度出发进行街道分类与定位、关注地域特征与集约性生态设施的环境营造方法以及提升步行道功能多样性和空间相容性的建议。     

鼎湖山马尾松、荷木混交林生态系统碳素积累和分配特征

选取鼎湖山保护区3个马尾松9Pinus massoniana),荷木（Schima superba)针阔混交林样地,研究其生态系统的碳素积累和分配特征。结果表明,鼎湖山马尾松,荷木混交林乔木尾生物量（thm^-2)为：174.41-270.11。平均227.36,且均以马尾松的生物量居多（占54.9%-84.4%)。林下层植物生物量和地表现存凋落物量（thm^-2)分别为7.41-28.28和7.06-11.56。平均14.41和9.03。三个混交林生态系统总碳贮量（thm^-2)分别为146.35,215.30和205.79。平均为189.15,其中植被层碳贮量贡献率最大,依次占62.9%,61.9%和69.9%。平均65.0%;土壤层贡献率次之,依次占34.3%,35.5%和28.5%。平均32.8%;而地表现存凋落物层的贡献最小,仅占2.8%,2.6%和1.6%。平均为2.3%。此外,本文还对该生态系统植被碳吸存潜力进行了讨论。     

敌百虫对水丝蚓的毒害

采用急性毒性方法测定了被不同浓度敌百虫毒害的水丝蚓(Limnodilus hoffineisteri)半致死浓度(LC50),利用测定酶活性方法检测了水丝蚓超氧化物歧化酶(SOD)的变化及中毒后水丝蚓喂饲的强壮水螅(Hydra robusta)SOD的改变。(1)敌百虫对水丝蚓48 h LC50为3.29 mg/L。敌百虫对水丝蚓SOD活性影响显著(P<0.05):在低浓度1~4 mg/L时,SOD活性呈上升趋势,但随浓度增加至5 mg/L,SOD活性开始下降。(2)用1~8 mg/L中毒后的水丝蚓依次喂饲水螅,SOD活性呈上升趋势。实验结果表明,敌百虫作为重要的杀虫剂或作为防治鱼病的药物,对水丝蚓造成胁迫,并在一定浓度范围内直接或间接地影响以其为食的动物的生存,以至危害生命。     

Molecular characterization of sawtooth oak (Quercus acutissima) germplasm based on randomly amplified polymorphic DNA

Sawtooth oak (Quercus acutissima) is a predominant tree species in the deciduous broad-leaved forest in China. It distributes in a large landscape area and can disperse in various ecology types. Molecular study on sawtooth oak can provide valuable information about the genetic diversity level and genetic relatedness on this important tree species. Insight into the genetic structure also provides resources of a species with its current feature and future evolutionary potential. The genetic structure of sawtooth oak was investigated by randomly amplified polymorphic DNA (RAPD). Twelve RAPD markers were used to assess genetic diversity of 408 individuals from 17 provenances enveloping most of the current distribution area of sawtooth oak. A total of 66 amplification products were detected, of which 49 bands (74.24 %) were polymorphic. Nei’s gene diversity, 0.2409, indicated a relatively high level of genetic variation in sawtooth oak germplasm. Analysis of molecular variance showed that most of the genetic diversity (87 %) was allocated within provenances. A combination of UPGMA dendrogram and STRUCTURE analysis was employed to estimate the genetic relationships of sawtooth oak germplasm; interestingly, the two methods presented similar grouping pattern with few discrepancies. Results revealed that 16 out of 17 provenances were clustered into one group, while the other 1 (LQ provenance) constituted a separate cluster. The data presented in this study suggested that the RAPD method was a valuable tool for estimation of genetic diversity and genetic relatedness of sawtooth oak germplasm. The present study also gave useful implications for germplasm conservation and new cultivar development for this promising energy tree species.     

研究报告: 组织蛋白酶B介导NLRP3小体在砷致小胶质细胞炎症激活中的作用

目的 探究组织蛋白酶B（CTSB）介导NLRP3小体在砷致小胶质细胞（BV-2）炎症激活中的作用。方法 取处于对数生长期的BV-2细胞，分别暴露于终浓度为0、2、4、8 μmol/L亚砷酸钠（NaAsO₂）溶液培养24 h，检测细胞活性，测定各组细胞内CTSB和细胞焦亡相关蛋白NLRP3、Caspase-1、IL-18、IL-1β的表达水平。流式细胞仪检测胞内溶酶体膜稳定性。基于实验结果，增设CTSB抑制剂组（5 μmol/L CA074-Me +8 μmol/L NaAsO₂、10 μmol/L CA074-Me+8 μmol/L NaAsO₂），检测两组细胞内炎症相关蛋白NLRP3、Caspase-1和IL-1β、IL-18的表达水平。结果 与对照组比较，各染砷组细胞抑制率增高，呈现剂量效应关系，溶酶体膜稳定性下降，差异有统计学意义（P<0.01），胞内CTSB、NLRP3、IL-1β、IL-18、Caspase-1表达增高，差异有统计学意义（P<0.01）；与对照组（8 μmol/L NaAsO₂）比较，抑制剂组BV-2细胞胞内CTSB、NLRP3、IL-1β、IL-18、Caspase-1水平均降低，差异有统计学差异（P<0.01）。结论 NaAsO₂通过诱导小胶质细胞内CTSB水平的上升，介导NLRP3炎症小体激活小胶质细胞，促其释放炎性因子，致神经系统损伤。     

理气调补汤对运动性疲劳大鼠血清皮质醇和白细胞介素2影响的研究

目的:通过观察理气调补汤对运动性疲劳大鼠血清皮质醇(C)和白细胞介素2(IL-2)水平的影响,以期揭示中药理气调补汤促进运动性疲劳恢复的作用机理.方法:健康雄性SD大鼠30只,随机分为对照组(Ⅰ组)8只、单纯运动组(Ⅱ组)11只、中药运动组(Ⅲ组)11只.实验时Ⅲ组每天定时定量中药灌胃1ml/100g体重,Ⅰ组、Ⅱ组灌胃相同剂量的生理盐水.实验采用游泳运动训练方式.6周末力竭训练后24h分离血清测定C和IL-2含量.结果:Ⅲ组大鼠游泳至力竭的时间较Ⅱ组显著延长;Ⅱ组和Ⅲ组大鼠血清IL-2浓度均显著低于Ⅰ组,但Ⅲ组大鼠血清IL-2浓度显著高于Ⅱ组;血清C浓度Ⅱ组显著高于Ⅰ组,Ⅲ组较Ⅱ组显著降低.结论:大强度运动训练可能导致HPA轴释放过量皮质醇,从而使免疫功能受到抑制.理气调补汤能够调节疲劳大鼠的HPA轴适应性,降低C的过量释放,维持免疫功能稳定,延缓疲劳的发生.     

Comparative investigation on spindle behavior and MPF activity changes during oocyte maturation between gynogenetic and amphimictic crucian carp

The spindle behavior and MPF activity changes in the progression of oocyte maturation were investigated and compared with cytological observation and kinase assay between gynogenetic silver crucian carp and amphimictic colored crucian carp.MPF activity was measured by using histone H1 as phosphorylation substrate.There were two similar oscillatory MPF kinase activity changes during oocyte maturation in two kinds of fishes with different reproductive modes,but there existed some subtle difference between them.The subtle difference was that the first peak of MPF kinase activity was kept to a longerlasting time in the gynogenetic silver crucian carp than in the amphimictic colored crucian carp.It was suggested that the difference may be related to the spindle behavior changes,such as tripolar spindle formation and spindle rearrangement in the gynogenetic crucian carp.