Penicillin-binding proteins in Proteus species.

Penicillin-binding proteins in three species of Proteus, Proteus mirabilis, P. morganii, and P. rettgeri, were investigated by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis. Penicillin-binding proteins in these Proteus species were compared with those in Escherichia coli K-12. An approximate correlation between penicillin-binding proteins in E. coli and those in Proteus species was shown by several criteria: electrophoretic mobilities; affinities of several beta-lactam antibiotics which show characteristic patterns of binding to penicillin-binding proteins in E. coli; relation between affinities of antibiotics to the proteins and effects on morphological changes in Proteus species; location of beta-lactamase activity among penicillin-binding proteins; and thermostability. The electrophoretic mobilities and several other characteristics of penicillin-binding proteins among the Proteus species examined were found to be similar from species to species and differed only slightly from those of E. coli.     

Floral volatiles, pollinator sharing and diversification in the fig-wasp mutualism: insights from Ficus natalensis, and its two wasp pollinators (South Africa)

Combining biogeographic, ecological, morphological, molecular and chemical data, we document departure from strict specialization in the fig-pollinating wasp mutualism. We show that the pollinating wasps Elisabethiella stuckenbergi and Elisabethiella socotrensis form a species complex of five lineages in East and Southern Africa. Up to two morphologically distinct lineages were found to co-occur locally in the southern African region. Wasps belonging to a single lineage were frequently the main regional pollinators of several Ficus species. In South Africa, two sister lineages, E. stuckenbergi and E. socotrensis, pollinate Ficus natalensis but only E. stuckenbergi also regularly pollinates Ficus burkei. The two wasp species co-occur in individual trees of F. natalensis throughout KwaZulu-Natal. Floral volatile blends emitted by F. natalensis in KwaZulu-Natal were similar to those emitted by F. burkei and different from those produced by other African Ficus species. The fig odour similarity suggests evolutionary convergence to attract particular wasp species. The observed pattern may result from selection for pollinator sharing among Ficus species. Such a process, with one wasp species regionally pollinating several hosts, but several wasp species pollinating a given Ficus species across its geographical range could play an important role in the evolutionary dynamics of the Ficus-pollinating wasp association.     

Evolution in action: molecular evidence for recent emergence of secotioid genera Endxoptychum, Gyrophragmium and Longula from Agaricus ancestors

Phylogenetic analyses of 29 Agaricus species and one representative from genera Endoptychum, Gyrophragmium and Longula each were conducted based on sequence data of the entire internal transcribed spacers and partial large subunit of ribosomal DNA. The Agaricus species formed several distinct clades both confirming and challenging previous morphological sections in several cases. Endoptychum depressum, Gyrophragmium dunalii and Longula texensis were nested among species of the genus Agaricus. This study provides evidence for independent emergence of these secotioid fungi from Agaricus ancestors, most likely from species placed in the section Arvenses as inferred from molecular data.     

四川省山蚋亚属一新种记述(双翅目,蚋科)

继作者于2005年首次发现并记述四川省山蚋亚属二新种之后,报道四川省山蚋亚属另1新种,Simulium (Montisimulium)jiajinshanense sp.nov.(夹金山山蚋).本新种与报告自中国的S.(M.)tibetense Deng et al.,1993(西藏山蚋)and S.(M.)moxiense Chen et al.,2005(磨西山蚋),阿塞拜疆的S.(M.)assadovi(Djafarav,1956),亚美尼亚的S.(M.)litshkense(Rubtsov,1947),哈萨克斯坦的S.(M.)quattuordecimfiatliatum(Rubtsov,1947)和塔吉克斯坦的S.(M.)quattuordecimfilum Rubtsov,1947相似,均具14条呼吸丝,但新种可依据食窦弓具中突,两性生殖器的特殊形态,茧简单和呼吸丝特殊分枝等综合特征和上述近缘种相区别.     

Immunological and physical comparison of monomeric and dimeric phosphagen kinases: Some evolutionary implications

The antigenic and physical properties of several representative invertebrate phosphagen kinases have been examined in order to further characterize the relationship between taxonomic assignment, quaternary protein structure and evolution of this class of enzymes. Antibodies against dimeric arginine kinase from the sea cucumber cross-reacted with dimeric arginine kinase purified from sea urchin eggs, but failed to react with extracts from any species known to contain monomeric arginine kinase. However, strong immunoreactivity was observed when antibodies against purified dimeric arginine kinase were reacted with pure creatine kinase from the human muscle (CK-MM) and brain (CK-BB) as well as extracts from several species known to contain dimeric creatine kinase. Of particular interest with regard to evolution of the phosphagen kinases, we confirm the presence of creatine kinase activity in the very primitive sponge Tethya aurnatium and detect a reaction with antibodies against dimeric, but not monomeric, arginine kinase. This observation is consistent with recent studies of phosphagen kinase evolution. Substrate utilization was very specific with creatine kinase using only creatine. Arginine kinase catalyzed phosphorylation of arginine but enzymes from several species could also phosphorylate canavanine. No activities were detected with d-arginine. Isoelectric points, evaluated for several pure arginine kinases suggest that generally the monomeric forms are more acidic than the dimeric proteins. Heat inactivation of arginine kinase in several species indicated a wide range of stabilities, which did not appear to be correlated with quaternary structure, but rather distinguished by the organism's environment. On the other hand, homodimeric arginine kinase proteins from species inhabiting disparate environments are sufficiently homologous to form a catalytically active hybrid.     

Heterochromatin and chromosome variation in cultivated species ofTulipa subg.Eriostemones (Liliaceae)

The chromosomes of several cultivatedTulipa species belonging to the subg.Eriostemones were examined using conventional staining and C-banding techniques. Most of the species have lightly banded chromosomes with heterochromatin content varying from nil to about 15%. The banding patterns of several taxa are described and discussed in regard to species relationships.     

Invasion of Mexico by Two Dung Beetles Previously Introduced into the United States

Following the Australian CSIRO strategies, the United States Department of Agriculture introduced several dung beetle species as a biological control to decrease the dung accumulation and proliferation of different pest fly species therein. Of these, two species have been very successful: Digitonthophagus gazella and Euoniticellus intermedius. They have expanded from their release sites in the United States, and quickly invaded Mexican territory and dispersed rapidly. Here we report on 27 new capture sites in several Mexican states from 1994 to 1996 and discuss invasion routes as well as ecological conditions.     

Systematics, biogeography, and evolution of the Neotropical peacock basses Cichla (Perciformes: Cichlidae)

To investigate forces influencing diversification in Neotropical fishes, the phylogenetic relationships among species and populations of the cichlid genus Cichla were examined. Mitochondrial DNA was sequenced for 454 individuals of the 5 nominal Cichla species and several putative undescribed species. Phylogenetic analyses support the distinction of two major clades of Cichla. Clade A includes C. temensis and two undescribed species from the lower Amazonas and Xingu Rivers. Clade B includes C. orinocensis, C. monoculus, C. ocellaris. C, intermedia, and an undescribed species from the upper Madeira River. Species boundaries were relatively well-circumscribed for clade B, while incomplete lineage sorting was inferred for clade A. Three probable instances of introgression were observed, including a regional population of C. orinocensis from the Negro River that shows a history of introgression. Biogeographic patterns from Cichla are partially congruent with those seen in several other Neotropical fish clades, and the diversification of Cichla species is inferred to result from both vicariance and sympatric divergence.     

Evolutionary trend in feeding habits of <Emphasis Type="Italic">Girella</Emphasis> (Perciformes: Girellidae)

Although some Girella species are herbivorous, having basically tricuspid teeth, some are omnivorous. To determine the evolutionary trends in feeding habits of Girella, the phylogenetic relationships of several species of Girella were estimated by partially sequencing the mitochondrially encoded NADH dehydrogenase subunit 2 gene, and the dentition and adductor mandibulae complex of each species were examined. The cladogram determined from the mitochondrial DNA analysis indicated that multiple tooth-rows containing incisor-like teeth existed in adults of the ancestral species of Girella, species with a single tooth-row of tricuspid teeth in the adult stage having diverged subsequently on several occasions. The tendinous connections between each section of the adductor mandibulae complex are believed to have been simple in the ancestral species, more complicated connections also having diverged later on several occasions. Multiple tooth-rows containing incisor-like teeth and the simple adductor mandibulae complex are deduced as adaptations to herbivory; on the other hand, a single tooth-row of tricuspid teeth and the complicated adductor mandibulae complex are deduced as adaptations to omnivory. Therefore, the ancestral species of Girella is suggested as having been adapted to herbivory, with species adapted to omnivory having diverged on several subsequent occasions.     

Speciation in the globeflower fly Chiastocheta spp. (Diptera: Anthomyiidae) in relation to host plant species, biogeography, and morphology

Phylogenetic relationships among the Chiastocheta species (Diptera, Anthomyiidae) were investigated using a 1320-bp mitochondrial DNA fragment including parts of cytochrome oxidase subunits I and II. Larvae of the Chiastocheta genus feed exclusively on Trollius (Ranunculaceae) seeds. Six Chiastocheta species (and two vicariant taxa) coexist on Trollius europaeus in Europe, where they were shown to be the sole pollinator of their host plant. In Asia, several Trollius species are parasitized by Chiastocheta spp., and several other Trollius species are free of Chiastocheta. The plant-insect association is thus obligate in Europe but facultative in Asia. This system therefore provides a unique opportunity to study the evolution of an obligate mutualism between a plant and its seed parasite pollinators and its consequences on insect diversification. Most parsimonious, distance, and maximum likelihood analyses of 16 haplotypes from Europe and 14 from Asia show that European species do not form a monophyletic group. The species relationship indicated by egg morphology is only partly supported by molecular data. Moreover, a strong discrepancy between nucleotide variation and male genitalia morphology variation was found, particularly within and among European species coexisting on a single host plant. Molecular divergence across species ranges from 0 to 4.6%, suggesting a recent origin of the genus and several events of diversification, involving both host shifts and within-host-plant radiation. We discuss alternative evolutionary scenarios that are consistent with molecular data.     

The acid-dependent conversion of major nuclear oligomeric polypeptides into a smaller species

Oligomeric polypeptides predominate among the nonhistone nuclear proteins of the avian erythrocyte. Two of these are converted to smaller species by several minutes in boiling aqueous buffer at pH values of 4.0–4.5 and below. Polypeptides corresponding to the species generated by this treatment are also isolated from the cell in the absence of acid treatment. This result indicates that several nuclear structural proteins could derive from a common polypeptide chain.     

Systematics and phylogeny of the Satyrium erectum group (Orchidaceae), with descriptions of two new species &om the Karoo region of South Africa

Two spectacular new orchid species from the semi-arid Karoo region of South Africa are described here. Both have been confused with Satyrium erectum Sw. in the past, yet have clear diagnostic characters which justify their recognition as distinct species. Satyrium pulchrumS. Johnson & Kurzweil sp. nov. , known only from an isolated granite inselberg in Namaqualand, appears to be the sister taxon to S. erectum, whereas Satyrium pallens S. Johnson & Kurzweil sp. nov. , known from several populations along the southern margins of the Karoo, has closer affinities to Saprium longicolleLindl. These four species form a distinct monophyletic group characterized by several synapomorphies. The allopatric distribution pattern and considerable divergence in floral characters of the sister species suggest that speciation involved shifts in the pollination system of geographically isolated populations.     

On some spiral-horned antelopes (Mammalia: Artiodactyla: Bovidae) from the Late Miocene of Turkey, with remarks on their distribution

Examination of some collections from several late Miocene Turkish localities allows us to describe and definitely identify for the first time several species of spiral-horned antelopes in this country:Palaeoreas lindermayeri, Protragelaphus skouzesi, Prostrepsiceros zitteli andNisidorcas sp. During the first part of the late Miocene, several endemic species are restricted to central Anatolia, while more widespread taxa appear in the later part of this period, suggesting a decrease in provinciality of this area.     

18S rRNA gene variation among common airborne fungi,and development of specific oligonucleotide probes for the detection of fungal isolates

In this study, we sequenced 18S rRNA genes (rDNA) from 49 fungal strains representing 31 species from 15 genera. Most of these species are common airborne fungi and pathogens that may cause various public health concerns. Sequence analysis revealed distinct divergence between Zygomycota and Ascomycota. Within Ascomycota, several strongly supported clades were identified that facilitate the taxonomic placement of several little-studied fungi. Wallemia appeared as the group most diverged from all the other Ascomycota species. Based on the 18S rDNA sequence variation, 108 oligonucleotide probes were designed for each genus and species included in this study. After homology searches and DNA hybridization evaluations, 33 probes were verified as genus or species specific. The optimal hybridization temperatures to achieve the best specificity for these 33 probes were determined. These new probes can contribute to the molecular diagnostic research for environmental monitoring.     

Isozyme variation among four species of the catfish genus Clarias

Native Thai species of Clarias catfishes and one species introduced from Africa can be easily distinguished by horizontal starch gel electrophoresis of allozymes. An undescribed species of Clarias was collected from Thailand and found to possess several fixed allelic differences from the Clarias previously studied.     

Heat shock increases the reliability of a temperate calcareous grassland seed bank study

Reliable assessment of the density and species richness of the viable seeds in the soil is essential to estimate the probability of successful restoration of a particular plant community. Since temperate calcareous grasslands contain several thermophilous species typical of fire prone habitats, heat shock can be expected to break dormancy of target species for calcareous grassland restoration. We tested the effect of heat shock on the estimated density and species richness of seeds in soil samples. Heat shock treatments between 70 and 110°C resulted in both a higher estimated seed density and estimated species richness, in particular of specialist calcareous grassland species. Moreover, 25 species germinated exclusively from the heat-treated samples. This indicates that several species would have been missed by handling soil seed bank samples following the standard germination protocol, resulting in an underestimation of the restoration potential.     

Evidence for UV-based sensory exploitation in Australian but not European crab spiders

Some crab spiders reflect UV-light, thereby creating a deceptive signal that attracts prey to the flowers that they sit on. We conducted a survey of several Australian and European species of crab spiders and found that UV-reflection is common in Australian species but absent from European species. Furthermore, honeybees are attracted to UV-reflecting Australian spiders while they are either indifferent to or repelled by European crab spiders. We do not know if UV-reflection evolved once or several times independently in crab spiders endemic to Australia or whether UV-reflective spiders arrived in Australia more recently.     

皇家爱丁堡植物园引种中国植物资源多样性及动态

本文通过对皇家爱丁堡植物园保存活植物名录数据库的查询,详细整理了近100年来该园从中国引种植物的数据,在此基础上详细分析了爱丁堡植物园引种中国植物的多样性、来源省份及不同阶段引种人（队）、引种主要类群、种类数量等。分析结果表明,从20世纪初到现阶段,爱丁堡植物园在持续不断地引种中国植物,上世纪80年代前主要以个人收集为主,每年收集成活几种到几十种,到90年代开始有专业考察队参与收集,每年收集成活种类数量有所增加,在90年初收集成活数量最多的一年达500多种,引种地区涉及我国的20余个省（市、地区）,其引种较多的地区为云南、四川、西藏和台湾。本文还探讨了在与生物资源相关知识产权保护日益关注的背景下,中国作为生物多样性大国在生物资源保护方面面临问题、挑战与对策。