镇海棘螈及濒危现状

本文简述了镇海棘螈的研究概况、外部形态、生活习性及其研究价值。调查资料表明,棘螈分布区极窄,数量甚少,已处于极度濒危。同时对濒危原因作了分析,提出了保护措施和建议。     

瘰螈属一新种——龙里瘰螈（有尾目：蝾螈科）

在贵州省龙里县水场乡采集到一批瘰螈标本,与瘰螈属已知物种比较后,确定其为一新种,即龙里瘰螈(Paramesotriton longliensis Li,Tian,Gu et Xiong sp.nov)。新种与尾斑瘰螈(Paramesotriton caudopunctatus)相似,但新种由于上鳃骨后端上翘,成体头部后端两侧鳃迹部位各有1个明显突起;体背嵴棱强烈隆起;指、趾两侧无缘膜,指、趾末端有黑色角质鞘;肛后尾的腹鳍褶橘红色,约在1/2处此颜色消失;雄螈尾后段浅紫红色无斑纹。统计并记述了新种的外形、头骨特征、染色体组型、生物学资料。     

中国疣螈属一新亚种

对采自河南省大别山区商城县的一种蝾螈科标本进行形态特征比较,发现与文县疣螈Tylototriton wenxianensis 相似,但存在明显差异;经与文县疣螈等4种蝾螈进行12S mt DNA部分序列比对,显示其与文县疣螈的遗传分化已达亚种级水平,因此定为1新亚种,文县疣螈大别亚种Tylototriton wenxianensis dabienicus ssp.nov..新亚种的主要鉴别特征为:头长远大于头宽;4肢较短,前后肢贴体相对指、趾端不相遇;前肢前伸,指末端达眼前角;泄殖腔孔周缘橘红色.     

龙里瘰螈与织金瘰螈的核型

用常规涂片法对贵州产龙里瘰螈Paramesotriton longliensis与织金瘰螈P. zhijinensis的染色体核型进行了研究。结果显示,龙里瘰螈的核型为2n=24=16m+8sm,染色体臂数NF=48,其中No.7、10、11、12为亚中着丝粒染色体(sm),其余均为中着丝粒染色体(m);织金瘰螈的核型为2n=24=20m+4sm,NF=48,其中No.9、11为sm,其余均为m。2种瘰螈的核型存在差异,可为2个物种的成立提供细胞遗传学佐证。     

瘰螈属(有尾目,蝾螈科)一新种

作者在贵州省织金县采集到一批蝾螈科瘰螈属动物标本,与该属已知物种比较后,确定其为1新种,即织金瘰螈Paramesotriton zhijinensis sp.nov。新种与尾斑瘰螈Paramesotriton caudopunctatus相似,但新种成体头部后端两侧各有3条退化的鳃迹,明显呈童体型;体背嵴两侧各有1条土黄色纵纹;指、趾两侧无缘膜,无内、外掌突;肛后尾腹鳍褶橘红色或橘黄色,约在后3/4处此颜色消失。本文统计并记述了新种的外形、头骨特征、生物学资料。     

我国棘螈属(Echinotriton)和疣螈属(Tylototriton)的研究概况

棘螈属（Echinotriton）和疣螈属（Tylototriton）均属于两栖纲有尾目蝾螈科.两属主要分布于我国西南、亚洲西南部、东南亚及日本.棘螈属在我国已知3种：Echinotriton andersoni（琉球棘螈）、E. Chinhaiensis（镇海棘螈）、E. Asperrimus（细痣棘螈）.疣螈属在我国已知4种：Tylototriton kweichowensis（贵州疣螈）、T. Shanjing（红瘰疣螈）、T.taliangensis（大凉疣螈）、T. Verrucosus（棕黑疣螈）.本文回顾了棘螈属和疣螈属物种的命名史,阐明了两属之间的关系,并从形态学、生态学、细胞遗传学和分子生物学方面对这两属的研究工作进行了综述.     

水蛭捕食两栖类卵

许多卵生动物具有对付食卵者的精巧策略以降低死亡率,因为早期发育阶段的捕食压力能显著影响具复杂生活史动物的生存。两栖动物卵被水蛭等很多物种所捕食。我们查阅了水蛭捕食两栖类卵的文献,发现27篇论文。在所报道的水蛭捕食两栖类卵的例子中,无尾类(3.6%,n=591)明显多于有尾类(1.6%,n=255)。此外,我们第一次记录到水蛭捕食四趾螈(Salamandrina perspicillata)卵,这也是西欧有尾类的第一例报道。我们没有发现两个两栖动物类群间存在差异。然而,当我们分别分析来自北美、欧洲和亚洲三个地区的数据时,发现北美的有尾类和无尾类间存在显著差异。水蛭可捕食各生活史阶段的两栖动物,因此,水蛭应归为一些两栖类的天敌。     

中国德氏瘰螈形态、分子系统分析和生境描述

中越边境地区是全球生物多样性的热点地区,近年来不断有新种、分布新记录种报道。2017年,学者首次报道了德氏瘰螈(Paramesotriton deloustali Bourret,1934)在中国的分布,但仅描述了其线粒体全序列,缺乏其他生物学信息。本研究于2013年在云南省红河州哈尼族彝族自治州河口县境内大围山保护区(22°37′N,103°52′E,海拔350 m)采集到6号标本应为德氏瘰螈,包括雄性成体标本4号和雌性成体标本2号,对其形态和生境特征进行了详细描述。此次采集标本与模式标本系列形态吻合。基于细胞色素c氧化酶亚基I(COI)基因的系统发育分析结果显示,河口大围山德氏瘰螈种群与模式产地(越南北部永福省三岛\"Tam Dao,Vinh Phuc Province\"风景区)种群间的遗传分化较小(p-distance为0.6%),与2017年所报道的云南标本聚为一支(p-distance为0.5%)。德氏瘰螈目前仅记录于中越边境地区,分布地极为狭窄,种群数量未知。为了更好地了解和保护包括该物种在内的中越边境生物多样性,建议两国学者进行更多的合作研究。     

Rediscovery of Paramecium duboscqui Chatton & Brachon, 1933, and a Description of Its Characteristics

ABSTRACT. Paramecium duboscqui Chatton & Brachon, 1933, was rediscovered in Harbin, China, in 1974. In addition to the morphological features described by Chatton and Brachon, more details such as the silver-line system, buccal apparatus, stomatogenetic pater, mating types and temperature adaptation are described here. Although minor differences exist between the strains from France and China, the evidence indicates that they are really the same species and a member of the bursaria group.     

Cloning,expression, and protective immunity in mice of a gene encoding the diagnostic antigen P-29 of Echinococcus granulosus

Taeniid tapeworm Echinococcus granulosus is the causative agent of Echinococcosis, an important zoonosis with worldwide distribution. In this study, a diagnostic antigen P-29 was cloned from E. granulosus and expressed in Escherichia coil Sequence analysis showed that EgP-29 contains 717-bp open reading frame and encodes a protein of 238 amino acid residues with a predicted molecular weight of 27.1 kDa. The recombinant EgP-29 （rEgP-29） could be recognized with antimice sera in Western blotting. The specific antibody was detected by enzyme-linked immunosorbent assay. Mice vaccinated with rEgP-29 and challenged intrapero itoneally with E. granulosus protoscoleces revealed sig- nificant protective immunity of 96.6% （P〈0.05）, compared with the control group. Thus, rEgP-29 protein is a promising candidate for an effective vaccine to prevent secondary echinococcosis.     

Efficacy of thymol against Echinococcus granulosus protoscoleces

The aim of the present work was to determine the in vitro protoscolicidal effect of thymol against Echinococcus granulosus. Protoscoleces of E. granulosus were incubated with thymol at concentrations of 10, 5 and 1 μg/ml. The first signs of thymol-induced damage were observed between 1 and 4 days post-incubation. The maximum protoscolicidal effect was found with thymol at 10 μg/ml, viability reduced to 53.5 ± 11.9% after 12 days of incubation. At day 42, viability was 11.5 ± 15.3% and, reached 0% after 80 days. Thymol at concentrations of 5 and 1 μg/ml provoked a later protoscolicidal effect. Results of viability tests were consistent with the tissue damage observed at the ultrastructural level. The primary site of damage was the tegument of the parasite. The morphological changes included contraction of the soma region, formation of blebs on the tegument, rostellar disorganization, loss of hooks and destruction of microtriches. The data reported in this article demonstrate a clear in vitro effect of thymol against E. granulosus protoscoleces.     

Purification and partial immunochemical characterization of a low molecular mass, diagnostic Echinococcus granulosus immunogen for sheep hydatidosis

Abstract A hydatid specific antigen of 8 kDa molecular mass was affinity-purified from crude hydatid cyst fluid. Some of the epitopes recognised by antibodies in the sera from sheep with hydatidosis were periodate-sensitive. The purified 8 kDa antigen was observed to be a thermo-stable glycoprotein in its immunochemical characteristics. By immunofluorescence on acetone-fixed protoscolices anti-8 kDa monospecific IgG antibodies indicated the existence of the 8 kDa molecule on the hooklets of protoscolices. The purified antigen was used in an enzyme-linked immunosorbent assay for the detection of specific antibodies in sera from sheep hydatidosis. Eighteen (90%) of 20 sera from sheep hydatidosis had antibodies to purified 8 kDa antigen while none of the sera from other parasitic infections or uninfected animals had any detectable levels of antibodies to 8 kDa antigen. Thus, the data on localization and recognition of hydatid specific 8 kDa molecule suggested that this may be one of the major molecules for specific immunodiagnosis and for modulating the hydatid disease process in infected hosts.     

中国特有濒危种川东灯台报春(报春花科)的重新发现

2006年6月份和9月份,作者在对重庆市城口县大巴山地区进行考察时,采集到了中国特有种川东灯台报春（Primula mallophylla）的标本,这是近百年来对该种除模式标本外的再度发现。根据在大巴山观察及采集到的材料,作者对过去该种的特征描述中存在的一些疑问进行了澄清,更正和补充了其形态描述;对历史上混淆的几个种列出了检索表;报道了该种的染色体数目及核型;根据国际通用的“红色名录等级及标准”对其濒危等级进行了评估。     

Rediscovery of Pedilanthus coalcomanensis (Euphorbiaceae), a threatened endemic Mexican species

Pedilanthus coalcomanensis was described from specimens collected by George B. Hinton in 1941 but was not collected again until 1999, when we found it in a tropical deciduous forest near Tehuantepec, in Chinicuila, Michoacán, Mexico. After analyzing Hinton's original collection notes, we concluded that this is the type locality. Based on the reduced geographic distribution presently known for this species (11 km(2)), the level of disturbance of its habitat, and the use of the method for the assessment of extinction risk in Mexican wild species (MER), we propose that P. coalcomanensis be covered by the appropriate Mexican legislation as a threatened species and be included in the Red List of Threatened Plants of the International Union for the Conservation of Nature. Our results help justify and delimit a local biosphere reserve in northwestern Michoacán, an area that is considered a center of endemism and that has largely been deforested. Our findings have implications for research on other historical specimens collected by Hinton in this region.     

Identification of membrane-bound and secreted proteins from Echinococcus granulosus by signal sequence trap

The signal sequence trap technique was applied to identify genes coding for secreted and membrane bound proteins from Echinococcus granulosus, the etiologic agent of cystic hydatid disease. An E. granulosus protoscolex cDNA library was constructed in the AP-PST vector such that randomly primed cDNAs were fused with a placental alkaline phosphatase reporter gene lacking its endogenous signal peptide. E. granulosus cDNAs encoding a functional signal peptide were selected by their ability to rescue secretion of alkaline phosphatase by COS-7 cells that had been transfected with the cDNA library. Eighteen positive clones were identified and sequenced. Their deduced amino acid sequences showed significant similarity with amino acid transporters, Krebs cycle intermediates transporters, presenilins and vacuolar protein sorter proteins. Other cDNAs encoded secreted proteins without homologues. Three sequences were transcribed antisense to E. granulosus expressed sequence tags. All the mRNAs were expressed in protoscoleces and adult worms, but some of them were not found in oncospheres. The putative E. granulosus secreted and membrane bound proteins identified are likely to play important roles in the metabolism, development and survival in the host and represent potential targets for diagnosis, drugs and vaccines against E. granulosus.     

Histological study of karaurids,the oldest known (stem) urodeles

Little is known about the initial phases of lissamphibian history (before the Cretaceous), because their fossil record is quite scanty. Only the morphology of the earliest members has been investigated, although other sets of data, from bone microanatomy and histology, are known to yield valuable paleobiological information. In the present study, we provide the first histological and microanatomical data on the oldest known stem-urodeles, the karaurids, from the Middle Jurassic. Three humeri from the Upper Bathonian, Oxfordshire, referred to juvenile or subadult individuals of Marmorerpeton and to an unnamed caudate of undetermined (but obviously non-larval) ontogenetic stage, were sampled in order to shed new light on the habitat and ontogeny of these basal caudates. The great compactness of the three humeri suggests that these salamanders were aquatic. The presence of extensive amounts of calcified cartilage in the humeri greatly strengthens the case for the presence of neoteny in these taxa, a suggestion that had initially been made on the basis of a few morphological characters. This constitutes the oldest known occurrence of neoteny in lissamphibians. Finally, bone histology reveals that the growth of Marmorerpeton and the related unnamed caudate was fairly slow and cyclic, a characteristic of extant lissamphibians.     

细粒棘球蚴AgB8/2基因的原核表达及免疫学鉴定

旨在克隆细粒棘球蚴 AgB8/2基因,优化原核表达体系,鉴定纯化蛋白并初步确定其诊断价值.采用 RT-PCR扩增 AgB8/2基因 cDNA,构建原核表达载体pET-AgB8/2并在大肠杆菌 BL21(DE3)中表达,优化表达条件.纯化的AgB8/2融合蛋白经 Western blot鉴定正确后,采用斑点免疫金渗滤法初步验证其血清学诊断价值.结果显示,克隆的 AgB8/2基因包含了 273 bp的完整ORF,序列分析表明与其它已报道的AgB8/2 cDNA序列的同源性在 99%～100%之间.优化的表达条件为,当菌液 OD600值为0.6时,加入终浓度为0.05 mmol/L的 IPTG,37℃,振荡培养5 h.纯化的蛋白经 Western blot鉴定为目的蛋白.克隆的 AgB8/2基因高度保守,原核表达载体pET-AgB8/2构建正确并高效表达可溶性融合蛋白,可作为特异性抗原应用于斑点免疫金渗滤法检测血清抗体.