豆科黄华属植物种子表面特征的研究

在扫描电镜下观察了豆科黄华属Thermopsis 18种植物种子的表面纹饰,发现 T．alpina,T.bar- bata,T．inflata,T．lupinoides,T. licentiana,T.smithiana和T．turkestanica的种子表面为粗网状,T californica,T.divaricarpa,T. macrophylla,T．mollis的种子表面为细网状,T.gracilis,T.montana,T. fabacea的种子表面为相对平滑型纹饰,T．alterniflora的种子表面为不规则条形,T．chinensis的种子表 面为粘膜状,T.rhombifolia的种子表面为条形及 T．viuosa的种子表面为碎屑状纹饰。结果表明黄华属的种子表面特征对属下类群的划分有一定意义,对澄清某些混乱的种有一定价值。     

榆科榉属模式的考证

长期以来,Zelkova crenata Spach被认为是榉属(Zelkova)的模式。作者基于国际植物命名法规中的模式指定原则,并通过有关文献的考证,确认Zelkova carpinifolia(Pall.) K. Koch为榉属的合法模式,而并非Z. crenata Spach或Z. carpinifolia(Pall.) Dipp.。     

长爪沙鼠ATPase8,ATPase6,COX3基因的克隆及序列分析

目的对长爪沙鼠线粒体ATPase8,ATPase6,COX3基因全序列进行测定,并对其进行鉴定及进化分析。方法根据长爪沙鼠已知基因序列设计引物,采用PCR产物测序法,对目的片段进行测序鉴定。结合已公布啮齿类动物ATPase8,ATPase6,COX3基因序列,分析其碱基组成、遗传距离、并基于最小进化法和UPGMA法构建系统进化树。结果获得长爪沙鼠线粒体ATPase8,ATPase6,COX3基因全序列,其与家鼠、小家鼠和仓鼠均具有较高的同源性（76～98%）;进化分析结果显示,长爪沙鼠与家鼠、黑家鼠和仓鼠遗传距离较近;碱基G的含量分别为6.9%,10.7%,15.2%,符合mtDNA的特点;A＋T含量分别为68.2%,64.1%,59.2%,明显低于G＋C含量,符合哺乳动物的特点。结论本研究为首次获得长爪沙鼠ATPase8,ATPase6,COX3基因全序列,长爪沙鼠与家鼠、黑家鼠和仓鼠具有较近遗传距离,本研究为长爪沙鼠进化研究、线粒体的结构和功能研究奠定基础。     

Biochemical Characterization of Individual Human Glycosylated pro-Insulin-like Growth Factor (IGF)-II and big-IGF-II Isoforms Associated with Cancer

Insulin-like growth factor II (IGF-II) is a major embryonic growth factor belonging to the insulin-like growth factor family, which includes insulin and IGF-I. Its expression in humans is tightly controlled by maternal imprinting, a genetic restraint that is lost in many cancers, resulting in up-regulation of both mature IGF-II mRNA and protein expression. Additionally, increased expression of several longer isoforms of IGF-II, termed “pro” and “big” IGF-II, has been observed. To date, it is ambiguous as to what role these IGF-II isoforms have in initiating and sustaining tumorigenesis and whether they are bioavailable. We have expressed each individual IGF-II isoform in their proper O-glycosylated format and established that all bind to the IGF-I receptor and both insulin receptors A and B, resulting in their activation and subsequent stimulation of fibroblast proliferation. We also confirmed that all isoforms are able to be sequestered into binary complexes with several IGF-binding proteins (IGFBP-2, IGFBP-3, and IGFBP-5). In contrast to this, ternary complex formation with IGFBP-3 or IGFBP-5 and the auxillary protein, acid labile subunit, was severely diminished. Furthermore, big-IGF-II isoforms bound much more weakly to purified ectodomain of the natural IGF-II scavenging receptor, IGF-IIR. IGF-II isoforms thus possess unique biological properties that may enable them to escape normal sequestration avenues and remain bioavailable in vivo to sustain oncogenic signaling.     

不同施肥处理对‘赤霞珠’葡萄根际土壤养分和真菌群落的影响

【背景】宁夏贺兰山东麓葡萄产区忽视有机肥的施用,果树枝条焚烧污染环境,造成土壤养分缺失,土壤质量下降。【目的】为解决长期施用化肥对土壤造成的一系列问题,通过大田试验研究施肥及喷施不同浓度菌剂对土壤理化性质、真菌群落组成及多样性的影响,为酿酒葡萄可持续健康发展提供科学依据。【方法】以‘赤霞珠’葡萄根际土壤为试验对象,采用Illumina MiSeq高通量测序技术,测定并分析根际土壤理化性质、真菌群落组成和多样性在7个处理[常规施肥(CK)、蚯蚓粪+腐熟枝条+100倍菌剂(T1)、蚯蚓粪+腐熟枝条+200倍菌剂(T2)、蚯蚓粪+腐熟枝条+300倍菌剂(T3)、蚯蚓粪+未腐熟枝条+100倍菌剂(A1)、蚯蚓粪+未腐熟枝条+200倍菌剂(A2)和蚯蚓粪+未腐熟枝条+300倍菌剂(A3)]的变化。【结果】相较于CK,葡萄根际土壤理化性质差异明显,施肥处理增加了土壤有机质含量,土壤pH含量无明显变化,改良了土壤结构,活化了土壤有效养分。相较于CK,各处理真菌分类操作单元(operational taxonomic unit, OTU)数均降低,A2处理根际土壤丰富度及多样性均显著增加。真菌群落组成...     

荒漠草原人工柠条林对冠下草本植物群落的保育作用

以宁夏盐池县荒漠草原人工柠条（Caragana intermedia）林为研究对象,分别选取柠条林冠下东侧（SE）,冠下西侧（SW）及带间（Gap）为研究样地,从群落水平探讨柠条对冠下草本植物群落结构、物种多样性及功能群分布的影响。结果表明：（1）在3种微生境中均鉴定出12种植物,SW以蒙古冰草为优势种,SE以蒙古冰草和中亚白草为优势种,Gap则以蒙古冰草和牛枝子为优势种。（2）与Gap相比,SW和SE植物群落的平均高度分别增加了41.06%和81.75%,地上生物量分别增加了40.88%和38.73%。SW和SE中,禾本科植物地上生物量分别占地上总生物量的67.10%和58.40%,显著高于Gap （P<0.05）。（3）柠条冠层效应使得草本植物的物种丰富度指数增加,但Shannon-Winner指数、Simpson指数和Pielou指数显著差异（P>0.05）,变化范围分别为1.620-1.756、0.701-0.730和0.775-0.878。（4）冗余分析表明：土壤温度、空气相对湿度及土壤有机碳是影响草本植物物种多样性及生物量的主要因子,解释量分别为42.70%,11.70%和8.80%。研究表明,柠条对冠下草本植物群落尤其是禾本科植物具有一定的保育作用,该效应的产生主要是由于柠条冠下微气候及土壤环境因子的改善为草本植物的生长发育提供了有利条件。柠条对草本植物的保育作用对荒漠草原生态环境的保护与恢复具有重要意义。     

Z:ZCLA长爪沙鼠微卫星标记的遗传多态性研究

通过对9个微卫星座位的扩增,研究了Z：ZCLA长爪沙鼠的遗传多态性。结果表明,Z：ZCLA长爪沙鼠在其中1个位点上只有一个等位基因,在其它位点上均有2～4个等位基因,平均等位基因数2．6个。平均杂合度0．4684,平均多态信息量0．4166,平均有效等位基因数2．1756。全群基因纯合度从0．1111～0．5555,平均0．3389,提示目前本群遗传多样性水平处于中度多态。     

用19个生化基因位点研究普通级Z:ZCLA长爪沙鼠的遗传多样性

目的调查Z:ZCLA长爪沙鼠原种群普通级长爪沙鼠的遗传多样性。方法用本实验室自行建立的长爪沙鼠19个生化基因位点的乙酸纤维素膜电泳技术并结合基本群体遗传学指标研究了普通级Z:ZCLA长爪沙鼠100个家系的遗传多态性。结果Z:ZCLA长爪沙鼠在Es-1、Car-2、Hbb、Gpi-1、Cs-1、Ce-2I、dh-l、Mod-1呈单态,在Es-2、Es-3、Es-4、Es-6、Es-8、Es-9、Es-10、pd-1、gm-1、Trf、Akp-1个位点上呈现多态性,等位基因从2~4个不等,平均等位基因数3.0,平均杂合度0.512,平均多态信息量0.455。结论提示目前本群遗传多样性水平处于中度多态。     

Genome sequencing and comparative analysis of three Chlamydia pecorum strains associated with different pathogenic outcomes

Background

Chlamydia pecorum is the causative agent of a number of acute diseases, but most often causes persistent, subclinical infection in ruminants, swine and birds. In this study, the genome sequences of three C. pecorum strains isolated from the faeces of a sheep with inapparent enteric infection (strain W73), from the synovial fluid of a sheep with polyarthritis (strain P787) and from a cervical swab taken from a cow with metritis (strain PV3056/3) were determined using Illumina/Solexa and Roche 454 genome sequencing.

Results

Gene order and synteny was almost identical between C. pecorum strains and C. psittaci. Differences between C. pecorum and other chlamydiae occurred at a number of loci, including the plasticity zone, which contained a MAC/perforin domain protein, two copies of a >3400 amino acid putative cytotoxin gene and four (PV3056/3) or five (P787 and W73) genes encoding phospholipase D. Chlamydia pecorum contains an almost intact tryptophan biosynthesis operon encoding trpABCDFR and has the ability to sequester kynurenine from its host, however it lacks the genes folA, folKP and folB required for folate metabolism found in other chlamydiae. A total of 15 polymorphic membrane proteins were identified, belonging to six pmp families. Strains possess an intact type III secretion system composed of 18 structural genes and accessory proteins, however a number of putative inc effector proteins widely distributed in chlamydiae are absent from C. pecorum. Two genes encoding the hypothetical protein ORF663 and IncA contain variable numbers of repeat sequences that could be associated with persistence of infection.

Conclusions

Genome sequencing of three C. pecorum strains, originating from animals with different disease manifestations, has identified differences in ORF663 and pseudogene content between strains and has identified genes and metabolic traits that may influence intracellular survival, pathogenicity and evasion of the host immune system.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-23) contains supplementary material, which is available to authorized users.