基于MaxEnt模型的腐烂茎线虫在内蒙古地区适生区预测

【目的】为保障马铃薯产业健康发展,加强腐烂茎线虫的检疫防控工作,对其在内蒙古地区的适生区进行预测分析。【方法】根据腐烂茎线虫在我国最新的分布和环境数据,通过MaxEnt生态位模型和ArcGIS软件,预测当前和未来气候条件下腐烂茎线虫在内蒙古地区的适生区。【结果】MaxEnt模型的AUC平均值为0.929,预测结果准确可靠。预测结果显示:当前气候条件下腐烂茎线虫在内蒙古地区的适生区面积为41.8万km²,占全区面积的35.31%。研究表明,在2021—2040年和2041—2060年,腐烂茎线虫在内蒙古地区的总适生区面积将不断扩大;其中在SSP1_2.6气候情景下,在赤峰市、通辽市和兴安盟将出现腐烂茎线虫的高适生区;在SSP3_7.0气候情景下,在鄂尔多斯市、赤峰市、通辽市将出现腐烂茎线虫高适生区。利用Jackknife刀切法计算得到影响腐烂茎线虫分布的主导环境因子为温度季节性变化方差、最湿月降雨量、最冷季平均温、昼夜温差月均温、最湿季平均温。【结论】腐烂茎线虫在内蒙古地区有进一步扩散的风险,建议在未来气候情景下出现腐烂茎线虫高度适生区的盟市,应加强调运检疫和疫情监测,防止腐烂茎线虫进一步扩散。     

气候变化对全球马缨丹分布影响的空间模拟

【目的】马缨丹是世界10种最有害的入侵杂草之一,预测其潜在适生区变化对入侵植物防控具有重要意义。【方法】以马缨丹为研究对象,采用有效分布点数据1744份和10个气候因子,使用MaxEnt模型和ArcGIS10.4软件,选用当前气候情景以及2050sSSP126、2050sSSP245、2050sRCP5.8、2090sSSP126、2090sSSP245、2090sSSP585 6个不同气候情景,对马缨丹全球潜在分布区进行预测。【结果】温度和降水因子是制约马缨丹入侵的主要因子,其中年降水量(bio12,48.6%)、最干季度的平均温度(bio9,36.4%)、温度季节性(bio4,4.6%)和最热季度的平均温度(bio10,4.2%)是制约马缨丹分布格局的主要环境因子。南美洲、非洲南部、亚洲南部以及澳大利亚北部和东部具有较高的入侵风险。从当前气候情景到2050年气候情景再到2090年气候情景的过渡中,其适生区面积呈增加趋势,其中高适生区面积持续增加。【结论】在水热条件以及生物因素3个层面上严格防控马缨丹入侵,以增加土著生态系统的完整性。     

气候变化下考氏白盾蚧的潜在分布区预测

【目的】评估园林植物害虫考氏白盾蚧Pseudaulacaspis cockerelli当前和未来在全世界的潜在分布区,揭示未来气候变化下考氏白盾蚧的分布动态,明确气候环境因素对其潜在分布的影响。【方法】以考氏白盾蚧为研究对象,基于考氏白盾蚧在全球的118条有效地理分布记录和19个环境变量,运用优化的MaxEnt模型和ArcGIS软件,推测气候变化下当前、2050年和2070年考氏白盾蚧的潜在分布格局,采用响应曲线确定环境变量的适宜区间,定量确定考氏白盾蚧未来气候条件下潜在地理分布动态。【结果】MaxEnt模型运算的平均曲线下面积(area under the curve, AUC)值为0.7182,表明该预测模型的预测精度比较高。当前考氏白盾蚧潜在地理分布的总适生区面积约为2.73×10⁷ km²,其中高适生区面积大约为4.37×10⁶ km²,占潜在可入侵总面积的16％,该区域主要位于美国与巴西西南沿海地区,印度西部地区及西部沿海区域,孟加拉国,越南北部大部,中国西南大部及华东华中大部,以及日本南部地区;在未来气候条件下,伴随着CO₂浓度的升高,考氏白盾蚧的高适生面积将显著增加。影响考氏白盾蚧的潜在地理分布的主要环境变量为平均月温差、昼夜温差与年温差比、最湿季平均温度和降水季节性,其中昼夜温差与年温差比的贡献率最高,达到38.8%。【结论】本研究结果表明考氏白盾蚧适宜生境主要受平均月温差和昼夜温差与年温差比的影响。本研究为考氏白盾蚧的综合防治提供重要依据和数据支撑。     

基于MaxEnt模型预测气候变化下杉木在中国的潜在地理分布

为研究杉木在中国的分布特征及其对气候变化的响应模式,本研究基于现有分布记录,应用最大熵(MaxEnt)模型和地理信息系统方法,结合气候、地形等环境要素,预测杉木在当前和未来气候变化下的潜在适生区。结果表明: 影响杉木分布的最主要因素是年平均降水量,在当前气候下,杉木适生区合计面积328万km²,占全国陆地总面积的34.5%,低、中和高适生区分别占18.3%、29.7%与52.0%。在未来气候情景下,杉木生长的适宜性在我国总体上呈上升趋势,适生区面积随气候变化增大,且明显向北扩张,南方湿润亚热带地区形成集中连片高适生区。模型经受试者工作特征曲线检验,训练集平均受试者工作特征曲线下面积为0.91,可信度高。     

入侵植物薇甘菊在贵州的潜在适生区及其变化趋势

【目的】薇甘菊是一种危害性极大的外来入侵植物,2016—2022年间,多次在贵州省发现其入侵种群。预测薇甘菊在贵州的潜在适生区及其变化规律,可对贵州薇甘菊防控体系建设提供依据。【方法】在全球筛选薇甘菊分布点1001个,结合22个环境因子数据,采用最大熵模型(MaxEnt)预测当前及未来气候条件下薇甘菊在贵州的潜在分布情况,并进行主导因子分析。【结果】当前气候条件下,薇甘菊在贵州的高适生区面积为1.51万km²,占全省面积的8.60%,主要位于黔西南州和黔南州;在未来气候条件下,薇甘菊在贵州的适生区呈扩增状态,适生区分布中心坐标(26.43°N,107.00°E)由黔南州向贵阳市转移;影响薇甘菊适生范围的主导因子是年平均温度、昼夜温差平均值、温度季节性变化、最冷月份最低温、年降水量和最热季平均降水量。【结论】薇甘菊在贵州的适生区范围广,温度和降水是主要影响因素。在未来气候条件下,薇甘菊在贵州的适生区呈扩增状态,整体向北迁移扩散的趋势明显。     

警惕一种新的外来入侵生物——木瓜粉蚧Paracoccus marginatus

【背景】木瓜粉蚧是一种重要的农林害虫,原产于中美洲地区,2008年起入侵南亚和东南亚多个国家并造成严重危害,目前在我国台湾和广州已有分布,对我国威胁极大。【方法】在收集、整理木瓜粉蚧原产地或入侵地的生物学、生态学、地理学等信息的基础上,介绍了木瓜粉蚧的形态特征、寄主植物、地理分布、危害和生物学特性,并利用Maxent生态位模型和Arc GIS对木瓜粉蚧在我国的潜在适生区进行了风险评估。【结果】木瓜粉蚧在长江流域以南地区具有广泛的适生区,华南地区在气候条件、寄主等方面利于木瓜粉蚧的生存和危害。【结论与意义】该虫对我国华南地区的潜在威胁十分巨大,亟需加强防范该虫扩散和暴发。     

烟草甲在我国的潜在地理分布

【目的】预测当前及未来气候场景下烟草甲Lasioderrmaserricorne(Fabricius)在我国的潜在地理分布,阐述烟草甲与气候因子之间的关系,为烟草甲的可持续治理提供理论基础。【方法】收集烟草甲的分布数据与气候数据,采用MaxEnt模型进行潜在地理分布研究,模拟烟草甲在当前与未来气候变化下的潜在地理分布的情况。【结果】最冷月的最低温度和最暖月的最高温度是影响烟草甲潜在地理分布的关键因素,烟草甲的高度适生区集中在我国南方,烟草甲的潜在地理分布未来有从北向南缩减的趋势。【结论】本研究筛选出了6个影响烟草甲的关键气候因子,预测了其在当前及未来气候场景下在我国的潜在地理分布,为烟草甲的绿色防控提供依据。     

基于随机森林模型和GIS的假臭草全国适生区预测

假臭草Praxelis clematidea已对我国南方植物造成严重危害，通过预测其在中国的适生区，可为农林部门制定与加强防控措施提供科学依据。以我国296个假臭草分布记录点、国内气候因子和地形因子为基础，利用随机森林模型和地理信息系统(GIS)技术预测其在我国的潜在适生区。随机森林模型预测结果可信；影响假臭草分布的主要环境因子是最冷月份最低温度，其次是年均降水量，而地形因子和土地利用类型的影响较小；假臭草的主要适生区域位于我国南方各省(区)，其中广东、广西、海南、福建、江西南部、云南西南部属于假臭草的高度适生区，占全国陆地面积8.08%；浙江沿海、江西中部、四川与重庆交界处等地区属于中度或一般适生区，占全国陆地面积2.32%和3.37%；低适生区和非适生区分别占全国陆地面积的9.09%和77.14%。在未来气候情景下，假臭草适生区总面积与现阶段相比无明显变化，但中度适生区面积增长明显，由2.32%增至4.33%。因此，在全球气候变暖的环境下，假臭草在国内还未达到最大繁殖范围，有持续扩散的可能性。     

栎方翅网蝽Corythucha arcuata(Say)在中国的潜在适生区预测

【目的】栎方翅网蝽是栎树上的一种重要害虫,自21世纪入侵意大利以来,迅速在欧洲地区暴发成灾。本文旨在探明栎方翅网蝽入侵中国的风险性。【方法】利用MaxEnt生态位模型预测栎方翅网蝽在中国的潜在适生区,分析栎方翅网蝽入侵、定殖和扩散的可能性。【结果】栎方翅网蝽入侵中国并在中国黄河长江中下游平原定殖和扩散的风险性极高,高度适生区包括重庆市、安徽省、湖北省、河南省、浙江省、湖南省、贵州省和四川省。通过分析环境因子重要性表明,最冷季度平均温度是影响栎方翅网蝽适应区的最关键环境变量;年平均温度、等温性和最干季度平均温度是影响栎方翅网蝽适应区分布的主要环境因素。【结论】栎方翅网蝽在我国定殖扩散风险高,建议植物检疫部门加强栎方翅网蝽的监控,并将栎方翅网蝽列入中华人民共和国进境植物检疫性有害生物名录。     

外来入侵杂草假苍耳在新疆地区的适生性分析及风险评估

【目的】假苍耳是一种恶性入侵杂草,预测其在新疆地区的潜在适生区并进行风险评估,旨在为其科学防控提供参考。【方法】采用MaxEnt模型与Arc GIS 10.4软件进行分析,预测假苍耳在新疆的潜在分布区,并划分风险等级。运用多指标综合评估方法,对假苍耳的危害风险性进行综合分析评估。【结果】假苍耳在新疆的适生区主要在北疆地区,适生区范围较广。高适生区主要包括克拉玛依市、昌吉回族自治州北部及塔城地区中部。年平均温(bio1)、最干季平均温(bio9)、最冷季平均温(bio11)及最热季平均温(bio10)是影响假苍耳分布的主要环境因子。假苍耳的危险性综合评价值为2.238,属于高度危险的有害生物。【结论】假苍耳目前在新疆仅分布在塔城地区,预测结果表明其在北疆地区继续扩散的趋势较大,需要提前制定好相应的管理和控制措施。     

Characterization of SSEA-1 glycolipids from the brain of a patient with fucosidosis

Neutral glycolipids from the brain of a patient with Fucosidosis were analyzed and two complex glycolipids containing five and eight sugars were isolated from the cortical grey matter. These two glycolipids reacted with antibodies recognizing the SSEA-1 [Le^x(X)] carbohydrate determinant. SSEA-1 glycolipids are normally expressed in human embryonic brain but are found in only small amounts in postnatal human brain. The accumulation of the two SSEA-1 glycolipids in Fucosidosis brain thus represents a defect which affects the normal developmentally regulated decrease in postnatal, expression of these glycolipids, and may be a contributing factor in the abnormal brain development associated with the disease. Chemical characterization of the two isolated glycolipids by gas chromatographic and mass spectrometric analyses has identified the two glycolipids as lacto-N-fucopentaosylceramide (III) and difucosyl-neolactonorhexaosylceramide.Abbreviations DCl direct chemical ionization - FAB tastatiom bombardment - GC gas chromatography - GSLs glycosphingolipids - MS mass spectrometry - SSEA-1 stage specific embryonic antigen-1 - TLC thin layer chromatographys     

Elucidation of Structure of Lipid A from the Marine Gram-Negative Bacterium Pseudoalteromonas haloplanktis ATCC 14393T

The chemical structure of lipid A, from the marine -proteobacterium Pseudoalteromonas haloplanktis 14393, a main product of lipopolysaccharide hydrolysis (1% AcOH), was determined using chemical methods and NMR spectroscopy. The lipid A was shown to be -1,6-glucosaminobiose 1,4-diphosphate acylated with two (R)-3-hydroxyalkanoic acid residues at C3 and C3 and amidated with one (R)-3-hydroxydodecanoyl and one (R)-3-dodecanoyloxydodecanoyl residue at N2 and N2, respectively.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Identification of novel oocyte and granulosa cell markers

Here we present novel gene expression patterns in the ovary as part of an ongoing assessment of published micro-array data from mouse oocytes and embryos. We present the expression patterns of 13 genes that had been determined by micro-array to be expressed in the mature egg, but not during subsequent preimplantation development. In-situ hybridization of sectioned ovaries revealed that these genes were expressed in one of two distinct patterns: (1) oocyte-specific or (2) expressed in both the oocyte and surrounding granulosa cells. Despite the fact that micro-array data demonstrated expression in the egg, several of these genes are expressed at low levels in the oocyte, but strongly expressed in granulosa cells. Eleven of these genes have no reported function or expression during oogenesis, indicating that this approach is a necessary step towards functional annotation of the genome. Also of note is that while some of these gene products have been well characterized in other tissues and cell types, others are relatively unstudied in the literature. Our results provide novel gene expression information that may provide insights into the molecular mechanisms of follicular recruitment, oocyte maturation and ovulation and will direct further experimentation into the role these genes play during oogenesis.     

Structural Peculiarities of Na+,K+-ATPase Isozymes from the Calf Brain

Functionally active preparations of Na⁺,K⁺-ATPase isozymes from calf brain that contain catalytic subunits of three types (1, 2, and 3) were obtained using two approaches: a selective removal of contaminating proteins by the Jorgensen method and a selective solubilization of the enzyme with subsequent reconstitution of their membrane structure by the Esmann method. The ouabain inhibition constants were determined for the isozymes. The real isozyme composition of the Na⁺ pump from the grey matter containing glial cells and the brain stem containing neurons was determined. The plasma membranes of glial cells were shown to contain mainly Na⁺,K⁺-ATPase of the 11 type and minor amounts of isozymes of the 22(1) and the 31(2) type. The axolemma contains 21 and 31 isozymes. A carbohydrate analysis indicated that 11 enzyme preparations from the brain grey matter substantially differ from the renal enzymes of the same composition in the glycosylation of the 1 isoform. An enhanced sensitivity of the 3 catalytic subunit of Na⁺,K⁺-ATPase from neurons to endogenous proteolysis was found. A point of specific proteolysis in the amino acid sequence PNDNR⁴⁹² Y⁴⁹³ was localized (residue numbering is that of the human 3 subunit). This sequence corresponds to one of the regions of the greatest variability in 1-, 2-, 3-, and 4-subunits, but at the same time, it is characteristic of the 3 isoforms of various species. The presence of the 3 isoform of tubulin (cytoskeletal protein) was found for the first time in the high-molecular-mass Na⁺,K⁺-ATPase 31 isozyme complex isolated from the axolemma of brain stem neurons, and its binding to the 3 catalytic subunit was shown.     

N-andO-glycosylation of glycoprotein C synthesized by Herpes simplex virus type 1-infected ricin resistant cells

The progeny of Herpes simplex virus type 1 (HSV-1) grown in ricin-resistant 14 cells (Ric^R14) lackingN-acetylglucosaminyltransferase I was released in the extracellular medium at a very low rate. By using a monoclonal antibody immobilized on Sepharose we purified from HSV-1-infected Ric^R14 cells a viral glycoprotein (gC), which carries bothN-andO-linked oligosaccharides. Glycopeptides obtained from [³H]mannoselabeled gC by Pronase digestion were entirely susceptible to endo--N-acetylglucosaminidase H, and the major oligosaccharide released was Man₄GlcNAc. The accumulation of this high-mannose species was related to the enzymic defect of the host cells and to the long retention of the viral glycoprotein within the cells. The extent ofO-glycosylation evaluated in [¹⁴C]glucosamine-labeled gC from Ric^R14 cells as compared to that of gC from wild type cells did not appear to be significantly modified.Abbreviations Con A concanavalin A - BHK cells baby hamster kidney cells - HSV Herpes simplex virus