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1.
2.
Abstract. The Pollenia viatica species-group ( =pallida species-group) is defined and described. It consists of P.bicolor Robineau-Desvoidy, P.bulgarica Jacentkovsk, P.fulvipalpis Macquart, P.mediterranea Grunin, P.ruficrura Rondani, stat.rev., P.viatica Robineau-Desvoidy, stat.rev. (= P.pallida Rodendorf, syn.n.) and P.ponti sp.n. It is mono-phyletic, mainly on the basis of a synapomorphic ovipositor tip, and the vagabunda species-group is its sister group. A key to all species is provided, the terminalia of both sexes illustrated and all taxa redescribed. Lectotypes are designated for Pollenia bisulca Pandellé, P.ruficrura Rondani and P.viatica Robineau-Desvoidy. Pollenia ruficrura is removed from its current status as a nomen dubium. Pollenia bicolor and P.ponti are western Mediterranean species, the latter also occurs in Czechoslovakia. P.fulvipalpis is endemic to France and Channel Islands. P.ruficrura is known only from Corsica and Italy. P.mediterranea is an eastern Mediterranean species reaching east to Armenia. P.bulgarica is distributed from Hungary to Caucasus. P.viatica is widespread from France, Great Britain and Southern Scandinavia to Central Asia. All species are summer or autumn species, and seem to have only one generation each year. The immature stages and life-cycle of a species from Paris, France, named 'Pollenia rudis' by Keilin (1909, 1915) are tentatively assigned to P. viatica . It survives the winter as a first instar larva within the earthworm Allolobophora chlorotica Savigny.  相似文献   

3.
McIvor  L.M.  Maggs  C.A.  & Stanhope  M.J. 《Journal of phycology》2000,36(S3):46-47
Polysiphonia harveyi Bailey was first described from Connecticut in 1848 and morphologically similar species, such as P. japonica and P. strictissima , have subsequently been described many times from different localities such as Japan and New Zealand, placing the taxonomy and nomenclature of this morphologically variable species in confusion. Polysiphonia harveyi is regarded as an alien in the British Isles and the north-eastern North Atlantic and is reported to be spreading rapidly. The first confirmed collection of P. harveyi from the British Isles was in 1908; the source of the British introduction remains unknown. In conjunction with breeding data, rbc L sequences for samples of P. harveyi , P. strictissima , P. japonica and P. akkeshiensis collected from New Zealand, Atlantic and Pacific North America, Japan and Europe, reveal that P. harveyi, P. japonica and P. akkeshiensis constitute a single biological species. The correct name for this is P. harveyi , whilst P. strictissima from New Zealand is a sibling species, distinct from P. harveyi. The center of genetic diversity of P. harveyi is in Japan. The original source of the introduced P. harveyi in the British Isles, Europe and Nova Scotia appears to be Hokkaido, Japan. Separate introductions from a single source population into New Zealand and Pacific and Atlantic North America from Honshu, Japan, apparently have occurred.  相似文献   

4.
The long term goal of this work is to understand synaptogenesis in homologous regions of the cerebral cortex, i.e. a whisker barrel. Hemispheres of aldehyde perfused mice, at various ages from P6 to P65 (DOB = P0; three each), were osmicated and sectioned at 40mm parallel to the pia. Barrels were identified, mapped and measured in sections through mid-level layer IV, and then embedded for electron microscopy. The main findings were: (1) Cell bodies and large diameter dendrites thin out in barrel hollows from P6 to P8. (2) Degeneration occurs primarily from P6 to P11, peaking on P8. (3) Single synapses from narrow, tubular axons predominate before P14; afterwards, multiple synapses from bag-like terminals increase in number. (4) The number of spines increases dramatically between P9 and P12. (5) Asymmetrical and symmetrical synapses occur at all ages studied; their junction lengths are not significantly different at any age. (6) Asymmetrical synapse density increases rapidly from P6 to P8, slowly from P9 to P 12, sharply between P13 and P14 along with patterned whisking, slowly to P20 and drops in adults. (7) Synapses onto spiny and non-spiny stellate cell bodies increase markedly from P10 to P20. (8) Changes in density of asymmetrical synapses in neuropil and of symmetrical synapses on spiny stellate cell bodies follow similar sequences but the sequence in neuropil is 72 h earlier. (9) When barrel size is taken into account, synaptogenesis is monotonic, increasing sharply in the second postnatal week followed by a slower increase into adulthood.  相似文献   

5.
Pennella sagitta (L.) is redescribed from fresh specimens recovered from Histrio histrio (L.) and from material in the collection of the Smithsonian Institution. A small, delicate parasitic copepod, P. sagitta is shown to be a valid species, found only on fishes of the family Antennariidae. Attempts of earlier workers to synonymize P. diodontis with P. sagitta are rejected, and the distinguishing features of both species are presented. A neotype is proposed from material described herein, due to a lack of the original holotype. A provisional review of the genus Pennella Oken, 1816 is provided, and the taxonomic status of 31 species is discussed. Pennella exocoetus is described from material in museum collections. Seven species, P. balaenoptera, P. diodontis, P. exocoetus, P.filosa, P. instructa, P. makaira and P. sagitta are considered as valid members of the genus. The remaining species are reduced to synonymy with valid species or accorded the status of species inquirendae.  相似文献   

6.
John A. Sved 《Genetics》1987,115(1):121-127
A two-generation crossing program was used to replace the entire chromosome complement of P strains by M strain chromosomes, the maternal contribution being from the P strain. The cytotype of chromosomally substituted females was indistinguishable from M strain cytotype, judged by the sterility of offspring from the cross of such females to P strain males. In addition, following replacement of the chromosomes, the level of DNA homologous to the P factor was sufficiently low to be explicable by low levels of P factor transposition. These results are consistent with immediate chromosomal control for the switching from P to M cytotype. However, the reverse chromosome substitution, replacing all chromosomes of an M strain with P chromosomes, did not usually lead to immediate change of cytotype properties, showing that there is a true maternal effect in the M to P direction. The absence of true maternal inheritance for P cytotype argues against models of P factor repression which depend on autonomous replication of a nonchromosomal element. The repression could still be explained by nonchromosomal copies of the P factor, provided that these are replenished from chromosomal P factors. A model is put forward in which P cytotype is due to the presence of circular P factors carrying a P factor target sequence, leading to preferential transposition of chromosomal P factors to nonchromosomal target sites.  相似文献   

7.
8.
We have analyzed the conserved regions of the gene coding for the circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria parasite. The closest evolutionary relative of P. falciparum, the agent of malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is consistent with the hypothesis that P. falciparum is an ancient human parasite, associated with humans since the divergence of the hominids from their closest hominoid relatives. Three other human Plasmodium species are each genetically indistinguishable from species parasitic to nonhuman primates; that is, for the DNA sequences included in our analysis, the differences between species are not greater than the differences between strains of the human species. The human P. malariae is indistinguishable from P. brasilianum, and P. vivax is indistinguishable from P. simium; P. brasilianum and P. simium are parasitic to New World monkeys. The human P. vivax-like is indistinguishable from P. simiovale, a parasite of Old World macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are evolutionarily recent human parasites, the first two at least acquired only within the last several thousand years, and perhaps within the last few hundred years, after the expansion of human populations in South America following the European colonizations. We estimate the rate of evolution of the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year. The divergence between the P. falciparum and P. reichenowi lineages is accordingly dated 8.9 Myr ago. The divergence between the three lineages leading to the human parasites is very ancient, about 100 Myr old between P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between P. falciparum and the other two.   相似文献   

9.
A gene for ribosomal protein P0 that belongs to the family of ribosomal P proteins was isolated from a Neurospora crassa cDNA library, using polyclonal antibodies against recombinant P0 protein from Saccharomyces cerevisiae. This is the first gene for ribosomal P0 protein to be cloned from filamentous fungi. The derived P0 protein sequence has a strong homology to other eukaryotic P0 proteins; yet, there is a notable alteration in the conservative C-terminal region, placing this protein among the unique sequences from protozoan parasites.  相似文献   

10.
Abstract. The Old World species of the genus Pygothrips are studied. Nine species are included. Four of them are previously known: P.mikrommatos (Moulton) from Fiji, P. pygus (Mound), P. rugicauda Hood and P. shavianus (Bagnall) from Australia. A further five species are new to science: P. breviceps from Japan, P. flavomaculatus from Obi Is., Indonesia, P. fusculus from Ogasawara Is., northwestern Micronesia, Japan, P. postocellaris from Fiji and P. vicinus from the Ryukyus, Japan. A key to species is provided.  相似文献   

11.
Faustulid trematodes (Digenea) from marine fishes of Australia   总被引:1,自引:0,他引:1  
Twelve species of faustulid trematode are described or redescribed from Australian marine fishes. Bacciger lesteri Bray, 1982 and B. sprenti Bray, 1982 are redescribed from Selenotoca multifasciata from Moreton Bay. It is suggested that the original host record for these species, Mugil sp., was incorrect. The genera Discogastroides, Odontocotyle and Pseudodiscogasteroides are synonymised with Paradiscogaster. The new combinations Paradiscogaster arabi (Hafeezullah & Siddiqi, 1970), P. hainanensis (Shen, 1970), P. indicus (Srivastava, 1939), P. macrostomus (Shimazu & Kamegai, 1990), P. ostracii (Yamaguti, 1934) and P. pritchardae (Gupta & Ahmad, 1978) are proposed. Discogasteroides hawaiensis Hanson, 1955 is synonymised with P. ostracii. P. macrostomus and P. ostracii are redescribed from Ostracion meleagris and O. cubicus from the Great Barrier Reef. P. farooqii Hafeezullah & Siddiqi, 1970 is redescribed from Monodactylus argenteus from Moreton Bay. The following new species are described: P. machidai n. sp. from Pomacanthus semicirculatus and P. sexstriatus from the Great Barrier Reef, P. dweorg n. sp. from Meuschenia galii, P. lobomyzon n. sp. from Tilodon sexfasciatus and P. habilis n. sp. from Pelates octolineatus, all from Western Australia. Antorchis pomacanthi (Hafeezullah & Siddiqi, 1970) Machida, 1975 is redescribed from Pomacanthus semicirculatus and P. sexstriatus from the Great Barrier Reef. The new combination Antorchis intermedius (Madhavi, 1975) is proposed for Parantorchis intermedius. Parayamagutia ostracionis is redescribed from O. cubicus from the Great Barrier Reef. Trigonocryptus conus is redescribed from Arothron hispidus from South-east Queensland and from A. nigropunctatus from the Great Barrier Reef. The new combination Trigonocryptus australiensis (Kurochkin, 1970) is proposed for Pseudodiscogasteroides australiensis. The Echinobrevicecinae is reduced to synonymy with the Faustulidae.  相似文献   

12.
Regulating the activity of the histidine autokinase CheA is a central step in bacterial chemotaxis. The CheA autophosphorylation reaction minimally involves two CheA domains, denoted P1 and P4. The kinase domain (P4) binds adenosine triphosphate (ATP) and orients the gamma phosphate for phosphotransfer to a reactive histidine on the phosphoacceptor domain (P1). Three-dimensional triple-resonance experiments allowed sequential assignments of backbone nuclei from P1 and P4 domains as well as the P4 assignments within a larger construct, P3P4, which includes the dimerization domain P3. We have used nuclear magnetic resonance chemical-shift-perturbation mapping to define the interaction of P1 and P3P4 from the hyperthermophile Thermotoga maritima. The observed chemical-shift changes in P1 upon binding suggest that the P1 domain is bound by interactions on the side opposite the histidine that is phosphorylated. The observed shifts in P3P4 upon P1 binding suggest that P1 is bound at a site distinct from the catalytic site on P4. These results argue that the P1 domain is not bound in a mode that leads to productive phosphate transfer from ATP at the catalytic site and imply the presence of multiple binding modes. The binding mode observed may be regulatory or it may reflect the binding mode needed for effective transfer of the histidyl phosphate of P1 to the substrate proteins CheY and CheB. In either case, this work describes the first direct observation of the interaction between P1 and P4 in CheA.  相似文献   

13.
Grant  R.F.  Robertson  J.A. 《Plant and Soil》1997,188(2):279-297
The uptake of P by plant root systems is believed to be controlled by the concentration of soluble orthophosphate at the root surface. If a P transformation model in which this concentration is calculated were coupled to a root and mycorrhizal growth model in which this concentration is used to calculate P uptake, then it should be possible to simulate P uptake under different soil and climate conditions if soil properties relevant to the control of P concentration are known. To test this idea, models for the transformation and transport of inorganic and organic P were coupled to ones for root growth and nutrient uptake as part of the ecosys modelling program. Seasonal estimates of soluble P concentration, root growth and P uptake from the combined models were tested with data measured from barley under fertilized and unfertilized treatments in a long term P fertilizer experiment conducted on two different soils. In both soils the fertilizer treatment increased simulated and measured soluble P concentrations from 0.1-0.2 to 0.2-0.4 g m-3, annual P uptake from 0.6-0.7 to 1.2-1.4 g m-2, and annual DM accumulation from 400-500 to 700-800 g m-2. Increases in soluble P concentrations caused by fertilizer P were reproduced in the model from changes in the balance between the desorption and dissolution of solid P on one hand, and the uptake of P by root and mycorrhizal systems on the other. Increases in P uptake caused by fertilizer P were reproduced in the model from higher solution P concentrations, root uptake kinetics, and from functional equilibria for C and P exchange simulated among mycorrhizal, root and shoot components of the plant. There was a tendency in the model to overestimate P uptake later in the growing season in the unfertilized treatment which could be corrected if parameters for root uptake kinetics were reduced after anthesis. Because the model is constructed independently of data for P uptake, and avoids the use of site-specific parameters, it may provide a means of estimating uptake under different managements and climates from soils of known properties.  相似文献   

14.
Protein synthesis is believed to be under control of the cell cycle during meiosis and mitosis. Any relationship between substrates for cdc2 kinase and components of the protein synthetic apparatus would therefore be of prime importance. During meiosis of Xenopus laevis oocytes one of the substrates for this kinase is a p47 protein, which is complexed to two other proteins, P36 and P30. Judged from partial amino acid sequence data on P47 and P30, the P30 and P47 proteins were reported to resemble the protein synthetic elongation factors (EF) 1 beta and 1 gamma from Artemia salina (Bellé, R., Derancourt, J., Poulhe, R., Capony, J.P., Ozon, R., and Mulner-Lorillon, O. (1989) FEBS Lett. 255, 101-104). This paper shows that the complex composed of P30, P47, and P36 from Xenopus is identical to the complex of EF-1 beta, EF-1 gamma, and EF-1 delta from Artemia according to two criteria. 1) Both stimulate elongation factor 1 alpha-mediated transfer RNA binding to ribosomes and exchange of guanine nucleotides on elongation factor 1 alpha to a comparable degree. 2) Each of the three subunits of the protein complex P30.P47.P36 from Xenopus shows a structural homology with one of the corresponding subunits of EF-1 beta gamma delta from Artemia. Presumably the phosphorylation of EF-1 gamma, which associates with tubulin at least in vitro, is important in processes following the onset of meiosis which is accompanied by a rise of protein synthesis.  相似文献   

15.
Hybrid speciation, or the formation of a daughter species due to interbreeding between two parental species, is a potentially important means of diversification, because it generates new forms from existing variation. However, factors responsible for the origin and maintenance of hybrid species are largely unknown. Here we show that the North American butterfly Papilio appalachiensis is a hybrid species, with genomic admixture from Papilio glaucus and Papilio canadensis. Papilio appalachiensis has a mosaic phenotype, which is hypothesized to be the result of combining sex-linked traits from P. glaucus and P. canadensis. We show that P. appalachiensis' Z-linked genes associated with a cooler thermal habitat were inherited from P. canadensis, whereas its W-linked mimicry and mitochondrial DNA were inherited from P. glaucus. Furthermore, genome-wide AFLP markers showed nearly equal contributions from each parental species in the origin of P. appalachiensis, indicating that it formed from a burst of hybridization between the parental species, with little subsequent backcrossing. However, analyses of genetic differentiation, clustering, and polymorphism based on molecular data also showed that P. appalachiensis is genetically distinct from both parental species. Population genetic simulations revealed P. appalachiensis to be much younger than the parental species, with unidirectional gene flow from P. glaucus and P. canadensis into P. appalachiensis. Finally, phylogenetic analyses, combined with ancestral state reconstruction, showed that the two traits that define P. appalachiensis' mosaic phenotype, obligatory pupal diapause and mimicry, evolved uniquely in P. canadensis and P. glaucus, respectively, and were then recombined through hybridization to form P. appalachiensis. These results suggest that natural selection and sex-linked traits may have played an important role in the origin and maintenance of P. appalachiensis as a hybrid species. In particular, ecological barriers associated with a steep thermal cline appear to maintain the distinct, mosaic genome of P. appalachiensis despite contact and occasional hybridization with both parental species.  相似文献   

16.
17.
Cuticular hydrocarbon (CH) profiles of four Periplaneta species were compared and their role in aggregation and interspecific recognition was evaluated. CH profiles are species specific and include from 19 to 25 hydrocarbons. P. brunnea, P. fuliginosa and P. australasiae have more CH components in common with one another than with P. americana. P. americana hydrocarbons include components from 24 to 43 carbon atoms but hydrocarbons for the three other species range from 21 to 41 atoms. The major compound in CH profiles in P. americana is 6,9-heptacosadiene that is absent from the three other species. The major compound in CH profiles of P. Brunnea and P. fuliginosa is 13-methyl pentacosane that is not found in the CH profile of P. americana. Major compounds in P. australasiae species are tricosene and 13-methyl pentacosane, respectively, in males and females. Binary choice tests demonstrated that specific CH extracts induced aggregation in the four species. High CH amounts were required to induce aggregation of P. americana and P. brunnea on conditioned sites, whereas low amounts were sufficient to induce aggregation of P. fuliginosa and P. australasiae. These results suggest that CHs are involved in aggregation and interspecific recognition.  相似文献   

18.
19.
中国卷尾猛蚁属系统分类研究(膜翅目:蚁科)   总被引:1,自引:0,他引:1  
记载中国卷尾猛蚁属Proceratium Roger4种:伊氏卷尾猛蚁P.itoi(Forel)分布于浙江、台湾和湖南,赵氏卷尾猛蚁P.zhaoi Xu,sp.nov.新种分布于云南,日本卷尾猛蚁P.japonicum Santschi分布于台湾,长腹卷尾猛蚁P.longigaster Karavaiev分布于云南,为中国新纪录种。文中编制了中国4种工蚁的分种检索表。  相似文献   

20.
Paranoplocephala maseri n. sp. is described from Lemmiscus curtatus (Cope) in the USA. The new species is related to Paranoplocephala omphalodes (Hermann, 1783), P. caucasica (Kirschenblat, 1938), P. kirbyi Voge 1948, P. microti (Hansen, 1947) and P. macrocephala (Douthitt, 1915) sensu Genov et al. (1996). P. maseri n. sp. differs from P. omphalodes in the position of the genital pores, testes and cirrus-sac; from P. caucasica, in which there is an unarmed cirrus, in both the distribution and larger number of testes; from P. kirbyi in the distribution of the testes, the position of the genital pores and egg dimensions; from P. microti in the distribution and smaller number of testes, the smaller egg dimensions and the position of the genital pores; and from P. macrocephala in the position of genital pores and cirrus-sac.  相似文献   

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