Polydactylus bifurcus, a new species of threadfin from Lombok Island, Indonesia (Perciformes: Polynemidae)

Polydactylus bifurcus sp. nov. is described on the basis of a single specimen collected from Lombok Island, Indonesia. The new species is distinguished from all other Indo-Pacific Polydactylus species by the following combination of characters: 15 pectoral fin rays, 5 pectoral filaments, 69 pored lateral line scales, 30 gill rakers, second spine of first dorsal fin very strong and lateral line bifurcated on caudal fin base, extending to posterior margins of upper and lower caudal fin lobes. Received: October 19, 2000 / Revised: April 21, 2001 / Accepted: April 25, 2001     

The archetype Pseudomonas aeruginosa proteins TssB and TagJ form a novel subcomplex in the bacterial type VI secretion system

In Pseudomonas aeruginosa three type VI secretion systems (T6SSs) coexist, called H1‐ to H3‐T6SSs. Several T6SS components are proposed to be part of a macromolecular complex resembling the bacteriophage tail. The T6SS protein HsiE1 (TagJ) is unique to the H1‐T6SS and absent from the H2‐ and H3‐T6SSs. We demonstrate that HsiE1 interacts with a predicted N‐terminal α‐helix in HsiB1 (TssB) thus forming a novel subcomplex of the T6SS. HsiB1 is homologous to the Vibrio cholerae VipA component, which contributes to the formation of a bacteriophage tail sheath‐like structure. We show that the interaction between HsiE1 and HsiB1 is specific and does not occur between HsiE1 and HsiB2. Proteins of the TssB family encoded in T6SS clusters lacking a gene encoding a TagJ‐like component are often devoid of the predicted N‐terminal helical region, which suggests co‐evolution. We observe that a synthetic peptide corresponding to the N‐terminal 20 amino acids of HsiB1 interacts with purified HsiE1 protein. This interaction is a common feature to other bacterial T6SSs that display a TagJ homologue as shown here with Serratia marcescens. We further show that hsiE1 is a non‐essential gene for the T6SS and suggest that HsiE1 may modulate incorporation of HsiB1 into the T6SS.     

Taxonomic notes on Metasasa and Indocalamus nanunicus (Poaceae: Bambusoideae)

Based on comprehensive field observations and careful herbarium studies, we discuss the status of the type species of Metasasa W. T. Lin (M. carinata W. T. Lin) and entities previously treated as synonyms of its name. Three species in two genera were involved. First, M. carinata and M. albofarinosa W. T. Lin were confirmed to be conspecific and a new combination Acidosasa carinata (Lin) D. Z. Li & Y. X. Zhang is proposed. Secondly, although M. carinata was previously treated as a synonym of Acidosasa nanunica (McClure) C. S. Chao & G. Y. Yang, close morphological study revealed that these two are not conspecific. Pseudosasa nanunica (McClure) Z. P. Wang & G. H. Ye is restored to accommodate this distinct species. Finally, another name previously treated as a synonym of A. nanunica, Pseudosasa acutivagina T. H. Wen & S. C. Chen should also be resumed. Synonyms are provided for each of these three species.     

Analysis of peripheral blood lymphocyte phenotypes and Th1/Th2 cytokines profile in the systemic immune responses of Helicobacter pylori infected individuals

H. pylori elicits specific humoral and cellular immune responses in the mucosal immune system. However, the type and extent of T lymphocyte response in the systemic immune system is not clear for H. pylori positive patients. In this study, peripheral blood T lymphocyte phenotypes and serum Th1/Th2 based cytokines of 32 H. pylori positive patients were analyzed and compared to those of healthy controls. While αβ TCR⁺ lymphocytes and their phenotype analysis were not significantly different to those of healthy controls, the percentage of pan γδ TCR⁺ lymphocytes was up to 2.4 times greater in the H. pylori positive group then in healthy controls. Furthermore, significant increases in IL‐10 concentrations in serum samples of H. pylori patients indicated that their immune systems had switched toward a Th2 type immune response. The correlation between phenotype and type of T cell response in the peripheral blood during H. pylori infection is discussed.     

The last step towards a full revision of Hieracium sect. Vulgata in Sweden

This article presents a summary of what has been achieved during the last 20 years within the project ‘The hawkweeds (Hieracium s.s.) of Sweden’ in general, and concerning Hieracium sect. Vulgata in particular, a review of our present understanding of the taxonomy and evolution of this group, as well as some new results and classifications that will be implemented in a forthcoming monographic treatment of the section in Swedish. A complete nomenclatural checklist (including synonyms and type material) of the 229 accepted species is included as an appendix and these species have been assigned to 23 informal species aggregates based on a multi‐variate analysis based on morphology and what is known about their ploidy level and molecular variation. Complete lists of the morphological characters considered important in the group as well as relevant literature are also included as appendices. Seven species are described as new to science or newly elevated to the rank of species: H. anderssonii T. Tyler, H. chroocentrum (Dahlst. ex Zahn) T. Tyler, H. cramiceps T. Tyler, H. hemimaculatum T. Tyler, H. maculato‐ornatum T. Tyler, H. ragnarii T. Tyler and H. vietulifolium (Johanss. & Sam.) T. Tyler.     

A multivariate analysis of morphological variation in the Hemizygia bracteosa complex (Lamiaceae, Ocimeae)

The variation and recognition of taxa within the Hemizygia bracteosa complex was examined using multivariate techniques. Morphological characters were sampled on 197 herbarium specimens. Phenetically H. bracteosa and H. welwitschii overlap in many floral characters. However differences in leaf characters and habit maintain their morphological distinctness from each other and they are therefore upheld as species. Hemizygia ornata, synonymized under H. welwitschii in recent treatments of the genus Hemizygia, differentiates from H. welwitschii on the basis of differences in leaf and floral characters and its reinstatement at specific level is here proposed. The concept of H. linearis is revised on account of the type specimen separating from all other elements of the taxon used in the analyses. The latter form a coherent group with H. petrensis and H. canescens thus negating any attempt to give any of them specific recognition. It is proposed that they should be synonymized under the earliest name H. canescens. The specific boundary of H. petiolata is revised but its specific status maintained.     

A new species of peyronellaea from Indian soil

Summary A new species of genusPeyronellaea, P. indianensis sp. nov., has been described. Its isolation from the soil is the first record to science. It differs from previously recorded five species parasitizing various host plants. As it is isolated on a filter paper buried in the soil, it is a cellulose decomposing fungus     

Helicobacter pylori adhesins: review and perspectives

It is highly unlikely that chronic infection with H. pylori could occur in the absence of adhesin–host cell interactions. Also, there is no evidence that any of the serious outcomes of H. pylori infection such as gastric and duodenal ulcers, gastric cancer or mucosa‐associated lymphoid tissue (MALT) lymphoma could occur without prior colonization of the gastric epithelium mediated by H. pylori adhesins. H. pylori is highly adaptable, as evidenced by the fact that it can occupy a single host for decades. An important facet of this adaptability is its ability to physically interact with various types of host cells and also with host mucins and extracellular matrix proteins using a number of different adhesins displaying a variety of unique receptor specificities. Thus it is highly unlikely that any one particular H. pylori adhesin will ever be proven responsible for a particular outcome such as duodenal ulcer, MALT lymphoma, or adenocarcinoma. Also, while the search for additional H. pylori adhesins should and certainly will continue, we suggest that the scope of this effort should be expanded to include investigations into the patterns of expression and interaction between individual outer membrane proteins. Which of the numerous H. pylori outer membrane proteins (OMPs) actually function as adhesins (i.e., have receptor‐binding sites) and which OMPs are simply necessary for optimal display of the adhesive OMPs? There are many other important questions about H. pylori adhesins waiting to be answered. For example, which adhesins are responsible for loose adherence to host cells and which adhesins are responsible for intimate, or membrane‐to‐membrane, adherence, and do these adhesins normally work in concert or in a sequential fashion? Also, is a specific type of adhesin necessary for type IV protein translocation into host cells and, if so, is adhesin expression coregulated with the effector protein export?     

Hieracium sect. Oreadea (Asteraceae) in Sweden – from a complete mess to a preliminary taxonomic classification

Among Swedish Hieracium sect. Oreadea (Fr.) Arv.‐Touv., more than 100 taxa have been recognized by various experts but, except for a regional monograph from 1894 there are no thorough published revisions of the group and many of the names have never been validly published. At the same time, some of the oldest names have been variously applied to morphologically clearly different species. In the present study, 5000 specimens in Swedish herbaria have been revised using both traditional and statistical morphometric methods and the complicated nomenclature has been disentangled. Twenty‐eight species are recognized and described with diagnostic keys and illustrations aiding identification and their known distributions are mapped. Six species are described as new to science (viz. H. marinum T. Tyler, H. eulasium Dahlst. ex T. Tyler, H. victoriae T. Tyler, H. falcifolium Johanss. ex T. Tyler, H. guldbergense Folin ex T. Tyler and H. hispidosum Dahlst. ex T. Tyler) and 3 additional names are raised to the specific rank (viz. H. gigantocybe (Dahlst.) T. Tyler, H. hilare (Dahlst. ex Omang) T. Tyler and H. tanyphyllum (Dahlst. ex Zahn) T. Tyler). Lectotypes are designated for 50 names based on material from Sweden, Norway or Finland and one name is neotypified. Except for a few infraspecific names for which all original material appears to be lost, all names based on material from Sweden are typified. However, it is concluded that albeit the number of taxa is relatively low, the species of H. sect. Oreadea are morphologically less distinct and clear‐cut than those of other widespread Scandinavian sections of the genus. Many of the characters that are most important in other sections of the genus are either invariable or unreliable in H. sect. Oreadea. Thus, the taxonomy has to rely on characters more subjected to environmentally‐induced modification. Furthermore, members of this section exhibit great morphological plasticity, possibly connected to their preference for exposed rocky habitats where the environmental conditions may be both severe and unpredictable.In addition, due to their ecological demands, they are confined to habitats that have always been both strongly fragmented and restricted in size giving rise to multiple small and locally adapted local populations. The section is here circumscribed in agreement with previous Scandinavian authors, i.e. including both the H. schmidtii‐group sometimes referred to H. sect. Stelligera and the H. norvegicum group approaching H. sect. Tridentata, but it is concluded that the section is relatively heterogeneous and that further studies aiming at the identification of more natural supraspecific taxa are much needed.     

Hcp and VgrG1 are secreted components of the Helicobacter hepaticus type VI secretion system and VgrG1 increases the bacterial colitogenic potential

The enterohepatic Epsilonproteobacterium Helicobacter hepaticus persistently colonizes the intestine of mice and causes chronic inflammatory symptoms in susceptible mouse strains. The bacterial factors causing intestinal inflammation are poorly characterized. A large genomic pathogenicity island, HHGI1, which encodes components of a type VI secretion system (T6SS), was previously shown to contribute to the colitogenic potential of H. hepaticus. We have now characterized the T6SS components Hcp, VgrG1, VgrG2 and VgrG3, encoded on HHGI1, including the potential impact of the T6SS on intestinal inflammation in a mouse T‐cell transfer model. The H. hepaticus T6SS components were expressed during the infection and secreted in a T6SS‐dependent manner, when the bacteria were cultured either in the presence or in the absence of mouse intestinal epithelial cells. Mutants deficient in VgrG1 displayed a significantly lower colitogenic potential in T‐cell‐transferred C57BL/6 Rag2^?/? mice, despite an unaltered ability to colonize mice persistently. Intestinal microbiota analyses demonstrated only minor changes in mice infected with wild‐typeH. hepaticus as compared with mice infected with VgrG1‐deficient isogenic bacteria. In addition, competitive assays between both wild‐type and T6SS‐deficient H. hepaticus, and between wild‐type H. hepaticus and Campylobacter jejuni or Enterobacteriaceae species did not show an effect of the T6SS on interbacterial competitiveness. Therefore, we suggest that microbiota alterations did not play a major role in the changes of pro‐inflammatory potential mediated by the T6SS. Cellular innate pro‐inflammatory responses were increased by the secreted T6SS proteins VgrG1 and VgrG2. We therefore concluded that the type VI secretion component VgrG1 can modulate and specifically exacerbate the innate pro‐inflammatory effect of the chronic H. hepaticus infection.     

In vivo phenotyping of the ob/ob mouse by magnetic resonance imaging and 1H-magnetic resonance spectroscopy

Objective: We studied ob/ob and wild‐type (WT) mice to characterize the adipose tissues depots and other visceral organs and to establish an experimental paradigm for in vivo phenotyping. Research Methods and Procedures: An in vivo evaluation was conducted using magnetic resonance imaging and ¹H‐magnetic resonance spectroscopy (¹H‐MRS). We used T1‐weighted images and three‐dimensional spin echo T1‐weighted images for the morphological analysis and ¹H‐MRS spectra on all body mass, as well as ¹H‐MRS spectra focalized on specific lipid depots [triglyceride (TG) depots] for a molecular analysis. Results: In ob/ob mice, three‐dimensional evaluation of the trunk revealed that ～64% of the volume consists of white adipose tissue, which is 72% subcutaneous and 28% visceral. In vivo ¹H‐MRS showed that 20.00 ± 6.92% in the WT group and 58.67 ± 6.65% in the ob/ob group of the total proton content is composed of TG protons. In in vivo‐localized spectra of ob/ob mice, we found a polyunsaturation degree of 0.5247 in subcutaneous depots. In the liver, we observed that 48.7% of the proton signal is due to water, whereas in the WT group, the water signal amounted to 82.8% of the total proton signal. With the sequences used, the TG amount was not detectable in the brain or kidneys. Discussion: The present study shows that several parameters can be obtained by in vivo examination of ob/ob mice by magnetic resonance imaging and ¹H‐MRS and that the accumulated white adipose tissue displays low polyunsaturation degree and low hydrolipidic ratio. Relevant anatomical alterations observed in urinary and digestive apparatuses should be considered when ob/ob mice are used in experimental paradigms.     

NEW DISTRIBUTION RECORD FOR CHILOGLANIS BIFURCUS JUBB AND LE ROUX, 1969 IN A TRIBUTARY OF THE CROCODILE RIVER,MPUMALANGA PROVINCE,SOUTH AFRICA

Summary

A new distribution record for the South African Red Data fish species Chiloglanis bifurcus was found in the Nels River at an altitude of 830 m a.m.s.l. in the Mpumalanga province, South Africa. Previously this species was known to occur between altitudes 900 m and 1200 m a.m.s.l. in the Elands and Crocodile Rivers of the Inkomati River system, as well as in tributaries of these rivers, namely the Gladdespruit, Stadspruit and Ngodwana River. It was also found to occur in the Komati River of the same river system.     

Sperm ultrastructure in honeycomb (foam) oysters (Mollusca,Bivalvia, Gryphaeidae,Pycnodontinae): comparison with other Ostreoidea and taxonomic implications

Sperm ultrastructural features of the honeycomb (foam) oysters Hyotissa hyotis, H. sinensis, and H. mcgintyi (Gryphaeidae) are described and compared with other Ostreoidea and more generally with other pteriomorphian Bivalvia. Spermatozoa of H. sinensis and H. mcgintyi (the type species of Parahyotissa Harry 1985) exhibit (1) a broad, low‐conical acrosomal vesicle; (2) subacrosomal material (very electron‐dense granular material and an almost electron‐lucent axial rod); (3) a spheroidal nucleus with a wide anterior invagination (filled with subacrosomal components); (4) a midpiece composed of four spherical mitochondria surrounding a pair of centrioles (rootlet associated with proximal centriole); and (5) a flagellum. Sperm of Hyotissa hyotis (type species of Hyotissa Stenzel 1971) differ markedly from those of H. sinensis and H. mcgintyi, in having (1) a conical acrosomal vesicle showing coarse granular texture anteriorly; (2) a very electron‐dense axial rod; (3) a barrel‐shaped nucleus with a long, narrow anterior invagination (filled with both subacrosomal components) and a basal invagination partly housing the proximal centriole; and (4) five midpiece mitochondria and no proximal centriolar rootlet. Results indicate that H. sinensis should be relocated to another genus, possibly a revised genus Parahyotissa, and also show that the sperm of H. sinensis and H. mcgintyi show many similarities to those of the Ostreidae, with the exception that the ‘axial rod’ component of the subacrosomal material is less electron‐dense than the surrounding substance (more dense in Ostreidae, as in H. hyotis). No family defining sperm features of the Gryphaeidae can be identified.     

The calanoid copepods of the Nile system

At least 11 or 12 calanoid taxa occur in the Nile system. One species is typical of the river and of Lake Chad (Th. galebi); two are restricted to Lake Victoria (Th. galeboides, T. stuhlmanni), but both might be only subspecies to more widespread species. One is restricted to Lakes Edward and George (T. worthingtoni) but is a little known species. No calanoids are on record from Lakes Albert and Kyoga, while the species reported from Lake Turkana (T. banforanus) is out of range, and almost certainly represents an erroneous record. Among the remaining species, four are East-African, ranging from the southern tip of the continent to the Ethiopian plateau and the Nile valley (P. schultzei, Th. mixtus, T. kraepelini, T. cf orientalis), while two are Sahelian species that span Africa from east to west (M. mauretanicus, T. processifer et ssp.).Two new synonyms are introduced. One new subspecies (T. processifier friedae) is described from the Ethiopian plateau. It is suggested that Tropodiaptomus orientalis (Brady, 1886), the type species of its genus, should not be considered a nomen dubium, but should be redescribed on its type female(s) and on topotypical males from Sri Lanka.     

Mutants inducible for sexual agglutinability in Saccharomyces cerevisiae

Summary We have isolated the mutants, T55s-41(a) and T562s-161 () which have no sexual agglutinability when cultured at 28°C, but become sexually agglutinable by the action of the sex pheromone produced by respective opposite mating type. The sex-specific glycoproteins responsible for sexual agglutination were detected in the mutants treated with the opposite mating type pheromone, but not in those treated with the same mating type pheromone.The induction of sexual agglutinability by the pheromone required both nitrogen and carbon sources and was inhibited by cycloheximide. The induction by the pheromone of sexual agglutinability was much more sensitive to osmotic shock and Triton X-100 in T55s-41 than in H1-0, an inducible a strain found in our stock cultures. When cultured at 22°C both T55s-41 and T562s-161 produced respective agglutination substances without the sex pheromones.H1-0 carried more than one genes responsible for the inducibility (inducible genes). The inducible genes carried by T55s-41 and T562s-161 were recessive, possibly linked to none of the mating type locus, thr4 and his 4, and shown to be identical. The inducible gene in H22, an inducible a strain found in our stock cultures and at least one of the inducible genes in H1-0 were linked to the mating type locus. All the inducible genes observed so far were not specific to the mating type in their action.     

The confusing identity of Pternopetalum molle (Apiaceae)

The misapplication of the name Pternopetalum molle (Franch.) Hand.‐Mazz. has resulted in considerable taxonomic confusion in the genus, involving 11 names belonging to seven taxa (according to a recent treatment). A supplementary taxonomic revision of P. botrychioides (Dunn) Hand.‐Mazz., P. molle and P. vulgare (Dunn) Hand.‐Mazz. is presented, after a detailed examination of the morphological variation. Four new synonyms, P. longicaule var. humile R.H.Shan & F.T.Pu, P. molle var. dissectum R.H.Shan & F.T.Pu, P. radiatum (W.W.Smith) P.K.Mukherjee and P. trifoliatum R.H.Shan & F.T.Pu, are proposed. Pternopetalum delicatulum (H.Wolff) Hand.‐Mazz. should be reduced to P. botrychioides rather than P. radiatum. The previous taxonomic treatments of P. cuneifolium (H. Wolff) Hand.‐Mazz., P. cartilagineum C.Y.Wu ex R.H.Shan & F.T.Pu and P. molle var. crenulatum R.H.Shan & F.T.Pu are reinstated. A key and distribution maps are provided for the accepted species. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 274–295.     

Expression of CEACAM1 or CEACAM5 in AZ‐521 cells restores the type IV secretion deficiency for translocation of CagA by Helicobacter pylori

Helicobacter pylori represents an important pathogen involved in diseases ranging from gastritis, peptic ulceration, to gastric malignancies. Prominent virulence factors comprise the vacuolating cytotoxin VacA and the cytotoxin‐associated genes pathogenicity island (cagPAI)‐encoded type IV secretion system (T4SS). The T4SS effector protein CagA can be translocated into AGS and other gastric epithelial cells followed by phosphorylation through c‐Src and c‐Abl tyrosin kinases to hijack signalling networks. The duodenal cell line AZ‐521 has been recently introduced as novel model system to investigate CagA delivery and phosphorylation in a VacA‐dependent fashion. In contrast, we discovered that AZ‐521 cells display a T4SS incompetence phenotype for CagA injection, which represents the first reported gastrointestinal cell line with a remarkable T4SS defect. We proposed that this deficiency may be due to an imbalanced coexpression of T4SS receptor integrin‐β₁ or carcinoembryonic antigen‐related cell adhesion molecules (CEACAMs), which were described recently as novel H. pylori receptors. We demonstrate that AZ‐521 cells readily express integrin‐β₁, but overexpression of integrin‐β₁ constructs did not restore the T4SS defect. We further show that AZ‐521 cells lack the expression of CEACAMs. We demonstrate that genetic introduction of either CEACAM1 or CEACAM5, but not CEACAM6, in AZ‐521 cells is sufficient to permit injection and phosphorylation of CagA by H. pylori to degrees observed in the AGS cell model. Expression of CEACAM1 or CEACAM5 in infected AZ‐521 cells was also accompanied by tyrosine dephosphorylation of the cytoskeletal proteins vinculin and cortactin, a hallmark of H. pylori‐infected AGS cells. Our results suggest the existence of an integrin‐β₁‐ and CEACAM1‐ or CEACAM5‐dependent T4SS delivery pathway for CagA, which is clearly independent of VacA. The presence of two essential host protein receptors during infection with H. pylori represents a unique feature in the bacterial T4SS world. Further detailed investigation of these T4SS functions will help to better understand infection strategies by bacterial pathogens.     

铜绿假单胞菌T6SS的组装、分泌、功能和调控

作为一种对抗真核细胞和原核细胞的强有力细菌武器,Ⅵ型分泌系统(type Ⅵ secretion system,T6SS)广泛存在于革兰氏阴性菌中。铜绿假单胞菌是一种对多种抗生素具有耐药性并能够在人体引发急性和慢性感染的条件致病菌,它编码3套独立的T6SS,分别为H1-、H2-和H3-T6SS。T6SS通过介导细菌间竞争、生物被膜的形成、金属离子的摄取以及与真核宿主细胞之间的相互作用,对铜绿假单胞菌在毒力和适应环境方面发挥重要作用。本文主要对铜绿假单胞菌T6SS的组装、效应蛋白的分泌、功能及调控机制展开综述,旨在为T6SS的研究提供一定的参考,并为铜绿假单胞菌感染的预防和治疗提供一定的指导。     

The noncanonical type III secretion system of Xanthomonas translucens pv. graminis is essential for forage grass infection

Xanthomonas translucens pv. graminis (Xtg) is a gammaproteobacterium that causes bacterial wilt on a wide range of forage grasses. To gain insight into the host–pathogen interaction and to identify the virulence factors of Xtg, we compared a draft genome sequence of one isolate (Xtg29) with other Xanthomonas spp. with sequenced genomes. The type III secretion system (T3SS) encoding a protein transport system for type III effector (T3E) proteins represents one of the most important virulence factors of Xanthomonas spp. In contrast with other Xanthomonas spp. assigned to clade 1 on the basis of phylogenetic analyses, we identified an hrp (hypersensitive response and pathogenicity) gene cluster encoding T3SS components and a representative set of 35 genes encoding putative T3Es in the genome of Xtg29. The T3SS was shown to be divergent from the hrp gene clusters of other sequenced Xanthomonas spp. Xtg mutants deficient in T3SS regulating and structural genes were constructed to clarify the role of the T3SS in forage grass colonization. Italian ryegrass infection with these mutants led to significantly reduced symptoms (P < 0.05) relative to plants infected with the wild‐type strain. This showed that the T3SS is required for symptom evocation. In planta multiplication of the T3SS mutants was not impaired significantly relative to the wild‐type, indicating that the T3SS is not required for survival until 14 days post‐infection. This study represents the first major step to understanding the bacterial colonization strategies deployed by Xtg and may assist in the identification of resistance (R) genes in forage grasses.