DISENTANGLING THE EFFECTS OF KEY INNOVATIONS ON THE DIVERSIFICATION OF BROMELIOIDEAE (BROMELIACEAE)

The evolution of key innovations, novel traits that promote diversification, is often seen as major driver for the unequal distribution of species richness within the tree of life. In this study, we aim to determine the factors underlying the extraordinary radiation of the subfamily Bromelioideae, one of the most diverse clades among the neotropical plant family Bromeliaceae. Based on an extended molecular phylogenetic data set, we examine the effect of two putative key innovations, that is, the Crassulacean acid metabolism (CAM) and the water‐impounding tank, on speciation and extinction rates. To this aim, we develop a novel Bayesian implementation of the phylogenetic comparative method, binary state speciation and extinction, which enables hypotheses testing by Bayes factors and accommodates the uncertainty on model selection by Bayesian model averaging. Both CAM and tank habit were found to correlate with increased net diversification, thus fulfilling the criteria for key innovations. Our analyses further revealed that CAM photosynthesis is correlated with a twofold increase in speciation rate, whereas the evolution of the tank had primarily an effect on extinction rates that were found five times lower in tank‐forming lineages compared to tank‐less clades. These differences are discussed in the light of biogeography, ecology, and past climate change.     

Integrating ancient patterns and current dynamics of insect–plant interactions: Taxonomic and geographic variation in herbivore specialization

Abstract The search for pattern in the ecology and evolutionary biology of insect–plant associations has fascinated biologists for centuries. High levels of tropical (low-latitude) plant and insect diversity relative to poleward latitudes and the disproportionate abundance of host-specialized insect herbivores have been noted. This review addresses several aspects of local insect specialization, host use abilities (and loss of these abilities with specialization), host-associated evolutionary divergence, and ecological (including “hybrid”) speciation, with special reference to the generation of biodiversity and the geographic and taxonomic identification of “species borders” for swallowtail butterflies (Papilionidae). From ancient phytochemically defined angiosperm affiliations that trace back millions of years to recent and very local specialized populations, the Papilionidae (swallowtail butterflies) have provided a model for enhanced understanding of localized ecological patterns and genetically based evolutionary processes. They have served as a useful group for evaluating the feeding specialization/physiological efficiency hypothesis. They have shown how the abiotic (thermal) environment interacts with host nutrirional suitability to generate “voltinism/suitability” gradients in specialization or preference latitudinally, and geographical mosaics locally. Several studies reviewed here suggest strongly that the oscillation hypothesis for speciation does have considerable merit, but at the same time, some species-level host specializations may lead to evolutionary dead-ends, especially with rapid environmental/habitat changes involving their host plants. Latitudinal gradients in species richness and degree of herbivore feeding specialization have been impacted by recent developments in ecological genetics and evolutionary ecology. Localized insect–plant associations that span the biospectrum from polyphenisms, polymorphisms, biotypes, demes, host races, to cryptic species, remain academically contentious, with simple definitions still debated. However, molecular analyses combined with ecological, ethological and physiological studies, have already begun to unveil some answers for many important ecological/evolutionary questions.     

成年大鼠阴茎海绵体cajal间质细胞的分离、培养与鉴定

目的:探索成年大鼠阴茎海绵体内cajal间质细胞(ICCs)的分离、培养和鉴定方法,为进一步研究其在阴茎海绵体中的作用提供条件.方法:取大鼠阴茎海绵体组织,采用酶消化法分离细胞,差速贴壁法相对纯化ICCs,将纯化后的细胞悬液接种于DMEM培养基中进行培养.通过倒置显微镜下观察细胞贴壁和形态,并用c-Kit特异性抗体标记细胞,免疫荧光法鉴定ICCs.结果:培养24小时后ICCs贴壁良好,细胞形态学观察显示ICCs呈纺锤状,有两个或多的突起,免疫荧光检验可见ICCs呈c-Kit抗体染色阳性.结果:用酶消化法可成功分离和培养大鼠阴茎海绵体ICCs,大鼠海绵体组织内ICCs的生理学功能有待进一步研究.     

973项目与国家重点实验室互动模式探讨

本文着重阐述了国家重点基础研究项目(973项目)与国家重点实验室互动的专业特性和管理特性,并通过以国家973创伤项目与创伤烧伤与复合伤国家重点实验室在人才、实验设备、科技资源共享方面的运行模式,初步总结其管理、合作、互动的有利建设经验,有望更好地提高国家资源的整体整合,并为适应新世纪学科发展,对加强群体创新和组织管理创新进行了有益的思考。     

患病大鲵中嗜水气单孢菌的分离鉴定及其防治

2009年5月,贵州省贵定县人工饲养的大鲵(娃娃鱼)发生了以四肢和腹侧的皮肤溃烂、口腔粘膜弥漫性出血以及肝脏肿大为临床病理特征的传染病。本研究对该传染病进行了病原分离、动物回归、菌株16S rRNA基因测序检测、药物敏感性、药物治疗及灭活乳化疫苗免疫保护方面的实验研究。试验结果表明,动物回归分离菌株与病原分离菌株其形态特征及理化特性一致,分离菌基因16S rRNA测序检测与嗜水气单胞菌的同源性达到99.57%以上,因此确诊该病为鱼类嗜水气单孢菌感染。致病株具有较强的耐药性,敏感药物治疗能抗菌,但皮肤溃烂组织、深部肌肉组织抗炎效果较差。经致病菌株灭活乳化免疫和免疫保护攻毒试验表明,灭活乳化疫苗免疫平均保护率达83.33%。     

Diptera of forensic importance in the Iberian Peninsula: larval identification key

A revision of the species and families of sarcosaprophagous flies (Diptera: Calliphoridae, Sarcophagidae, Muscidae, Fanniidae, Drosophilidae, Phoridae, Piophilidae and Stratiomyidae) suitable for forensic purposes in the Iberian Peninsula is presented. Morphological characteristics that allow the accurate identification of third instars of the species present in the Iberian Peninsula are described and presented in the form of a diagnostic key. For larval Calliphoridae, characteristics such as the spines of the body segments were useful for the genus Calliphora whereas features of the anal segment and the cephalopharyngeal skeleton were useful for larvae of Lucilia. Identification of three Chrysominae species present in the Iberian Peninsula is included. For larval Sarcophagidae, characters such as the arrangement and shape of spiracular openings, structures of the anal segment and the cephalopharyngeal skeleton were used for the first time. A new record of Sarcophaga cultellata Pandellé, from a human corpse, is also included as well as recent incursions into the European cadaveric entomofauna such as Synthesiomyia nudiseta (van der Wulp) and Hermetia illucens (Linnaeus). This work provides useful new information that could be applied to forensic investigations in the Iberian Peninsula and in southern Europe.     

ITS2 sequences as barcodes for identifying and analyzing spider mites (Acari: Tetranychidae)

The use of DNA barcodes, short DNA sequences from a standardized region of the genome, has recently been proposed as a tool to facilitate species identification and discovery. Here we show that second internal transcribed spacer of nuclear ribosomal DNA (rDNA-ITS2) barcodes effectively discriminate among 16 species of spider mites (Acari: Tetranychidae) from Israel. The barcode sequences of each species were unambiguously distinguishable from all other species and formed distinct, nonoverlapping monophyletic groups in the maximum-parsimony tree. Sequence divergences were generally much greater between species than within them. Using a 0.02 (2%) threshold for species diagnosis in our data set, 14 out of 16 species recognized by morphological criteria would be accurately identified. The only exceptions involved the low divergence, 0.011–0.015 (1.1–1.5%), between Tetranychus urticae and Tetranychus turkestani, where speciation may have occurred only recently. Still, these species had fixed alternative rDNA-ITS2 variants, with five diagnostic nucleotide substitutions. As a result, we tentatively conclude that rDNA-ITS2 sequence barcodes may serve as an effective tool for the identification of spider mite species and can be applicable as a diagnostic tool for quarantine and other pest management activities and decision-making. We predict that our work, together with similar efforts, will provide in the future the platform for a uniform, accurate, practical and easy-to-use method of spider mite species identification.     

Detection and identification of mycobacteria by mycolic acid analysis of sputum specimens and young cultures

Ziehl–Neelsen acid-fast staining and mycolic acid analysis of concentrated samples and Middlebrook 7H9 cultures were carried out on 127 sputum specimens to evaluate a rapid method for detecting and identifying mycobacteria by analyzing fluorescent derivatives of mycolic acids in concentrated sputum specimens and in Middlebrook 7H9 cultures and compare with mycobacterial detection using Lowenstein–Jensen (LJ) cultures. All samples were classified into five groups according to the number of acid-fast bacilli observed in the smear. The group of samples with 3+ acid-fast bacilli in the smear had the highest number of positive detections of mycolic acids in the concentrated samples and the Middlebrook 7H9 cultures (81.8 and 100%, respectively). The overall percentages of mycolic acid detection for both sample types were 43.2 and 91.3%, respectively. The mycolic acid analysis of the Middlebrook 7H9 cultures had the fewest false negative detections with respect to the LJ cultures. The analysis of fluorescent derivatives of mycolic acids, using HPLC, is useful for concentrated sputum samples with large number of bacilli (3+) and is preferred for Middlebrook 7H9 cultures, even for clinical specimens with a low number of bacilli. Furthermore, with this analytical method, the simultaneous detection and identification of mycobacteria is usually possible.     

中国西北地区松科和柏科气孔器形态

现代针叶树气孔器的研究为鉴定化石气孔器奠定了基础,对第四纪植被变化和古气候的研究起着很重要的作用,是第四纪孢粉学的一个重要补充。本文运用常规的标准的孢粉分析方法,对中国西北地区常见的松科3属8种和柏科3属4种植物气孔器进行了观察分析。结果表明凭气孔器大小可以区分松科与柏科。利用气孔器大小、T型结构的形状?上部木质片与气孔器茎之间的夹角进行属的鉴别,再结合茎的长度、宽度、中间木质部的宽、T型外角度和上部木质片外缘形状等可以进行种的鉴别,并编制了一个初步的检索表。