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1.
中国古蚤属分类研究(蚤目,栉眼蚤科)   总被引:2,自引:0,他引:2  
通过对我国现有古蚤属标本和有关资料进行全面整理和系统分类研究,认为目前我国已知古蚤属共有27种,它们隶属于4个种团,分别为钝刺古蚤种团obtuspina group(1种)、鼩鼱古蚤种团soricis group(2种)、偏远古蚤种团remota group(16种)和短额古蚤种团brevifrontata group(8种),其数量已近该属世界已知种的一半.文中分别对我国已知各种古蚤的鉴别特征、生物学和地理分布状况作了介绍,并编制了各种团、种及亚种检索表.根据它们的分布特征认为我国西南部横断山区可能是古蚤属的分布中心.文中对偏远古蚤种团目前存在的问题进行了讨论.  相似文献   

2.
A fragment ofhistone H4 gene (160 bp long) was sequenced in the standard strains of P. primaurelia (DQ067620), P. biaurelia (DQ067621), P. tetraurelia (DQ067622), P. pentaurelia (DQ067623), P. septaurelia (DQ067624), P. octaurelia (DQ067625), P. decaurelia (DQ067626), P. undecaurelia (DQ067627), P. dodecaurelia (DQ067628), P. tredecaurelia (DQ067629), and P. quadecaurelia (DQ067630). The tree constructed according to the Kimura model presents two main species clusters, one comprising P. undecaurelia, P. octaurelia, P. septaurelia, and the second cluster with P. pentaurelia, P. tredecaurelia, P. quadecaurelia, P. tetraurelia, P. decaurelia, P. primaurelia, P. biaurelia. P. dodecaurelia was recovered as a separate branch. The tree constructed on the basis of the maximum likelihood method also presents two species clusters, one with P. undecaurelia, P. octaurelia, P. septaurelia, and the second with P. primaurelia, P. decaurelia, P. pentaurelia, P. tredecaurelia, P. quadecaurelia, P. tetraurelia. P. biaurelia forms a basal clade to the latter cluster, and P. dodecaurelia was recovered as a clearly distinct branch from the clusters.  相似文献   

3.
A taxonomic treatment of the genus Ptyssiglottis including Ancylacanthus, Hallieracantha, Oreothyrsus , and Polytrema is given. The phylogeny is briefly dealt with. Leaf morphology, inflorescence morphology and pollen morphology yield important characters. The distribution of selected characters is mapped. The distribution of all species is mapped. Eight new species are published viz. P. campanulata, P. decurrens, P. fusca, P. glandulifera, P. longisepala, P. mucronata, P. pubescens , and P. stamino-difera . Fifteen new combinations are made viz. P. caudata, P. creaghii, P. cuprea, P. cyrtandroides, P. dulcamarioides, P. fastidiosa, P. glabrisepala, P. granulata, P. nigrescens, P. peranthera, P. psychotriifolia, P. pubisepala, P. salicifolia, P. sanguinolenta , and P. undulata .  相似文献   

4.
A taxonomic treatment of the genus Ptyssiglottis including Ancylacanthus, Hallieru-cantha, Oreothyrsus , and Polytrema is given. The phylogeny is briefly dealt with. Leaf morphology, inflorescence morphology and pollen morphology yield important characters. The distribution of selected characters is mapped. The distribution of all species is mapped. Eight new species are published viz. P. campanulata, P. decurrens, P. fusca, P. glandulifera, P. longisepala, P mucronata, P. pubescens , and P. staminodifera . Fifteen new combinations are made viz. P. caudata, P. creaghii, P. cuprea, P. cyrtandroides, P. dulcamarioides, P. fastidiosa, P. glabrisepala, P. granulata, P. nigrescens, P. peranthera, P. psychotriifolia, P. pubisepala, P. salicifolia, P. sanguinolenta , and P. undulata .  相似文献   

5.
Deoxyribonucleic Acid Homologies Among Some Pseudomonas Species   总被引:12,自引:2,他引:10       下载免费PDF全文
Phylogenetic relationships among a number of strains belonging to the genus Pseudomonas were explored by the use of in vitro deoxyribonucleic acid (DNA) hybridization. The fluorescent nomenspecies (P. fluorescens, P. putida, P. aeruginosa, P. cichorii, P. syringae, and related species), as well as the nonfluorescent species P. stutzeri, P. mendocina, P. alcaligenes, and P. pseudoalcaligenes, were shown to belong to a single DNA homology complex which is isolated from other Pseudomonas species that have been studied [P. cepacia (= P. multivorans), P. caryophylli, P. marginata (= P. alliicola), P. pseudomallei, P. acidovorans, P. testosteroni, P. solanacearum, P. diminuta, P. facilis, P. delafieldii, P. saccharophila, P. palleronii]. A limited numerical analysis of the phenotypic properties of the examined strains supported, with some exceptions, their previous allocation to nomenspecies and biotypes. The internal structure and nomenclature of the "P. fluorescens homology complex" are discussed.  相似文献   

6.
Electrophoretic analysis of murine anterior pituitary extract revealed five major proteins of Mr 13,000-18,000 (designated P13, P14, P16, P17, and P18 according to Mr), three of which, P16, P17, and P18, were markedly influenced by estradiol benzoate and perphenazine in a manner similar to that of growth hormone, and two, P13 and P14, to that of prolactin. Tyrosine peptide mapping showed partial resemblance of fingerprints for P16 and P17 (and possibly P18) to those for growth hormone, and of P13 and P14 to those for prolactin. Both P14 and P18 bound to Concanavalin A. None of the peptides crossreacted with antibodies to growth hormone or prolactin. The concentrations of P13 and P14 in pituitaries from lactating rats and in a prolactinoma were distinctly higher than normal. All five peptides were secreted into the medium during the in vitro incubation. These results suggest that P16, P17 and P18 are growth hormone- and P13 and P14 prolactin-related secretory proteins of the pituitary.  相似文献   

7.
中国西南地区杨属的分类学研究(Ⅰ)   总被引:1,自引:0,他引:1  
本文包括:康定杨的补充记载,4个新组合,16个新异名,2个天然杂种,2个分布新记录,2个新变种。  相似文献   

8.
Satellite bacteriophage P4 requires the products of the late genes of a helper phage such as P2 for lytic growth. Expression of the P2 late genes is positively regulated by the P2 ogr gene in a process requiring P2 DNA replication. Transactivation of P2 late gene expression by P4 requires the P4 delta gene product and works even in the absence of P2 DNA replication. We have made null mutants of the P2 ogr and P4 delta genes. In the absence of the P4 delta gene product, P4 multiplication required both the P2 ogr protein and P2 DNA replication. In the absence of the P2 ogr gene product, P4 multiplication required the P4 delta protein. In complementation experiments, we found that the P2 ogr protein was made in the absence of P2 DNA replication but could not function unless P2 DNA replicated. We produced P4 delta protein from a plasmid and found that it complemented the null P4 delta and P2 ogr mutants.  相似文献   

9.
Twenty-one new Polycentropodidae (Trichoptera) species are described: Polyplectropus aberrus, P. dorsospinus, P. nodyg, P. yndog, P. clavus, P. nathalae, P. millei, P. christinae, P. koueus, P. viklundi, P. hovmoelleri, P. aoupiniensis, P. tenerus, P. angustus, P. curvispinus, P. caledonia, P. piroguensis, P. triangulatus, P. pernodensis, P. taoensis, and P. papei spp. novae, representing the first species records of this family from New Caledonia. A key to males of the New Caledonian Polycentropodidae is provided, and distribution maps are presented for all species.  相似文献   

10.
Proteins of bacteriophage phi6.   总被引:18,自引:11,他引:7       下载免费PDF全文
We investigated the protein composition of the lipid-containing bacteriophage phi 6. We also studied the synthesis of phage-specific proteins in the host bacterium Pseudomonas phaseolicola HB10Y. The virion was found to contain 10 proteins of the following molecular weights: P1, 93,000; P2, 88,000; P3, 84,000; P4, 36,800; P5, 24,000; P6, 21,000; P7, 19,900; P8, 10,500; P9, 8,700; and P10, less than 6,000. Proteins P3, P9, and P10 were completely extracted from the virion with 1% Triton X-100. Protein P6 was partially extracted. Proteins P8 and P9 were purified by column chromatography. The amino acid composition of P9 was determined and was found to lack methionine. Labeling of viral proteins with [35S]methionine in infected cells indicated that proteins P5, P9, P10, and P11 lacked methionine. Treatment of host cells with UV light before infection allowed the synthesis of P1, P2, P4, and P7; however, the extent of viral protein synthesis fell off exponentially with increasing delay time between irradiation and infection. Treatment of host cells with rifampin during infection allowed preferential synthesis of viral proteins, but the extent of synthesis also fell off exponentially with increasing delay time between the addition of rifampin and the addition of radioactive amino acids. All of the virion proteins were seen in gels prepared from rifampin-treated infected cells. In addition, two proteins, P11 and P12, were observed; their molecular weights were 25,200 and 20,100, respectively. Proteins P1, P2, P4, and P7 were synthesized early, whereas the rest began to increase at 45 min post-infection.  相似文献   

11.
Two bacteriophage T4 proteins, P7 and P8, which are components of the phage baseplate have been purified to apparent homogeneity. P7 and P8 are the protein products of T4 genes 7 and 8. A plasmid has been constructed which contains approximately 5 kilobases of T4 DNA, including genes 7 and 8, under the control of the tac promoter. Induction of Escherichia coli W3110iQ cells containing this plasmid resulted in the production of functional P7 and P8. Standard protein isolation procedures were used to purify both P7 and P8 from extracts of induced cells. In T4-infected cells, these two proteins and P10 interact in a strictly ordered sequential manner (P10 + P7----P10/P7,P10/P7 + P8----P10/P7/P8) to form an intermediate in the baseplate assembly pathway. The three purified proteins assembled in vitro to form a limited number of oligomeric species, as determined by nondenaturing gel electrophoresis. P10 and P7 interacted in vitro to form two assemblies with distinct electrophoretic mobilities, both containing P10 and P7. Addition of P8 to this mixture resulted in the disappearance of both P10/P7 species and the appearance of a single new assembly with a different electrophoretic mobility. These interactions occurred without the addition of any catalyst or cofactors. Isolated P11 appeared to add as predicted to the in vitro-formed complexes without affecting the formation of the two P10/P7 or the single P10/P7/P8 intermediates. Interactions between P7 and P8 in the absence of P10 or interactions between P10 and P8 in the absence of P7 could not be detected. These data indicate that purified P10, P7, and P8 interact in vitro in a manner completely in accord with the published assembly pathway and thus establish a system for further study of the regulation of the formation of this assembly intermediate in vitro.  相似文献   

12.
This study analyzed five varieties of P. tomentosa and their putative parents, P. alba, P. davidiana, P. adenopoda and P. tremula by RAPD and artificial cross. Of 78 bands revealed by 13 arbitrary primers selected, 58 (74.36%) bands were polymorphic among P. tomentosa and four putative parents. The RAPD statistical results showed the relationship between P. tomentosa and P. alba or P. adenopoda was closer than that between P. tomentosa and P. davidiana or P. tremula . There were higher similarity and lower genetic distance between P. tomentosa and P. alba or P. adenopoda than that between P. tomentosa and the other two putative parents. The results from UPGMA, Fitch margoliash phylogenetic dendrogram were similar. In addition, artificial hybrids including reciprocal cross between P. alba and P. adenopoda were used to compare with five varieties of P. tomentosa . And those hybrids between P. alba as female and P. adenopoda as male were closer to P. tomentosa than those from reciprocal cross. The results demonstrated that P. tomentosa was a natural hybrid between P. alba as female parent and P. adenopoda as male parent.  相似文献   

13.
Rod photoreceptor cGMP phosphodiesterase (PDE6) consists of a catalytic subunit complex (Pαβ) and two inhibitory subunits (Pγ). In the accompanying article, using bovine photoreceptor outer segment homogenates, we show that Pγ as a complex with the GTP-bound transducin α subunit (GTP-Tα) dissociates from Pαβγγ on membranes, and the Pαβγγ becomes Pγ-depleted. Here, we identify and characterize the Pγ-depleted PDE. After incubation with or without guanosine 5′-O-(3-thiotriphosphate) (GTPγS), Pαβ complexes are extracted. When a hypotonic buffer is used, Pαβγγ, Pαβγ, and a negligible amount of a Pαβ complex containing Pγ are isolated with GTPγS, and only Pαβγγ is obtained without GTPγS. When an isotonic buffer containing Pδ, a prenyl-binding protein, is used, Pαβγγδ, Pαβγδδ, and a negligible amount of a Pαβ complex containing Pγ and Pδ are isolated with GTPγS, and Pαβγγδ is obtained without GTPγS. Neither Pαβ nor Pαβγγ complexed with GTPγS-Tα is found under any condition we examined. Pαβγ has ~12 times higher PDE activity and ~30 times higher Pγ sensitivity than those of Pαβγγ. These results indicate that the Pγ-depleted PDE is Pαβγ. Isolation of Pαβγγδ and Pαβγδδ suggests that one C-terminus of Pαβ is involved in the Pαβγγ interaction with membranes, and that Pγ dissociation opens another C-terminus for Pδ binding, which may lead to the expression of high PDE activity. Cone PDE behaves similarly to rod PDE in the anion exchange column chromatography. We conclude that the mechanisms for PDE activation are similar in mammalian and amphibian photoreceptors as well as in rods and cones.  相似文献   

14.
用RAPD探讨毛白杨起源   总被引:36,自引:0,他引:36  
利用RAPD分子标记对山杨、欧洲山杨、银白杨、响叶杨及毛白杨的5个不同类型,即抱头毛白杨、截叶毛白杨、易县毛白杨、陕西毛白杨和南京栽培的毛白杨进行了分析,并进行了银白杨×响叶杨正反交实验,研究杂种后代与毛白杨的关系。RAPD分析说明,毛白杨的亲缘关系与银白杨和响叶杨较近,而与山杨和欧洲山杨的亲缘关系则较远。毛白杨在聚类图上首先是与银白杨和响叶杨聚为一类,再与山杨和欧洲山杨聚在一起。通过比较毛白杨与银白杨和响叶杨的正反交子代,发现毛白杨更接近银白杨×响叶杨的子代,而与反交子代有所区别。由此可见,毛白杨为天然杂种是没有疑义的,而且很可能是银白杨×响叶杨的杂种。本研究筛选出的13个引物,产生了78条谱带,覆盖了基因组的一定区域,其可靠性是较高的。  相似文献   

15.
Sequence data of the rbc L –rbc S noncoding intergenic spacer of the plastid genome for 47 specimens of Porphyra and Bangia from the northeast Atlantic reveal that they fall into 11 distinct sequences: P. purpurea, P. dioica (includes a sample of P. "ochotensis" from Helgoland), P. amplissima (includes P. thulaea and British records of P. "miniata" ), P. linearis, P. umbilicalis, P. "miniata", B. atropurpurea s.l. from Denmark and B. atropurpurea s.l. from Wales, P. drachii, P. leucosticta (includes a British record of P. "miniata var. abyssicola" ), and P. "insolita" (includes P. "yezoensis" from Helgoland). Of these, data obtained for P. purpurea , P. dioica, P. amplissima, P. linearis, P. umbilicalis, P. drachii, and P. leucosticta were based on type specimens or material compared with types. Comparison of sequence data for Porphyra spp. and Bangia atropurpurea s.l. (including B. fuscopurpurea, the type species of Bangia ) confirms that the species are congeneric. The data also confirm that the number of layers that make up the Porphyra thallus are not taxonomically significant. Comparison of sequence data for species from the northeast Atlantic with those for material of two species from the Pacific reveals that the species fall into two distinct groupings: an Atlantic group, containing P. purpurea, P. dioica, P. amplissima, P. linearis, P. umbilicalis, P. "miniata", and B. atropurpurea, and a Pacific group, containing P. "pseudolinearis", P. drachii, P. leucosticta, P. "yezoensis" (including a sample of P. "tenera" ), and P. "insolita" (including P. "yezoensis" from Helgoland). The possibility of alien species in the northeast Atlantic is discussed.  相似文献   

16.
Characterization of Pseudomonas Species Isolated from Clinical Specimens   总被引:22,自引:10,他引:12       下载免费PDF全文
More than 90 morphological and physiological characters of 227 strains of pseudomonads isolated from clinical specimens and 16 reference strains are described. The clinical isolates included P. aeruginosa (apyocyanogenic), P. fluorescens, P. putida, P. pseudomallei, P. cepacia, P. acidovorans, P. alcaligenes, P. pseudoalcaligenes, P. stutzeri, P. putrefaciens, P. maltophilia, and P. diminuta.  相似文献   

17.
The polymerase chain reaction (PCR) was used to amplify the ITS2 region of nuclear ribosomal DNA from six Phytophthora species which comprise taxonomic Group IV. Digestion of the ca. 600 bp PCR product with restriction enzymes Alu I, Dra I, Hha I, Hinf I, Msp I, and Taq I revealed variation which allowed relationships among the species to be assessed. P. infestans , P. mirabilis and P. phaseoli were indistinguishable from one another with all enzymes tested. With Alu I and Taq I. P. ilicis , P. colocasiae . and P. hibernalis each showed unique banding patterns different from the common banding pattern shared by P. infestans . P. mirabilis . and P. hibernalis . Dra I allowed differentiation of P. ilicis and P. colocasiae from P. infestans , P. mirabilis , P. phaseoli , and P. hibernalis . all of which shared a common banding pattern. Hha I allowed differentiation of P. colocasiae and P. hibernalis from P. infestans, P. mirabilis, P. phaseoli , and P. ilicis . Hinf I allowed differentiation of P. ilicis and P. hibernalis , (each of which showed a unique banding pattern) from P. infestans, P. mirabilis, P. phaseoli , and P. colocasiae . Msp I allowed differentiation of P. hibernalis from the other five species. Species groupings determined by restriction analysis of ITS2 were consistent with those based on morphological criteria. These results show that restriction analysis of PCR-amplified TS2 regions can be useful as an adjunct to morphological criteria in Phytophthora species identification.  相似文献   

18.
The interactions among the yeast stalk components (P0, P1alpha, P1beta, P2alpha and P2beta) and with EF-2 have been explored using immunoprecipitation, affinity chromatography and the two-hybrid system. No stable association was detected between acidic proteins of the same type. In contrast, P1alpha and P1beta were found to interact with P2beta and P2alpha respectively. An interaction of P0 with P1 proteins, but not with P2 proteins, was also detected. This interaction is strongly increased with the P0 carboxyl end, which is able to form a pentameric complex with the four acidic proteins. The P1/P2 binding site has been located between residues 212 and 262 using different C-terminal P0 fragments. Immunoprecipitation shows the association of EF-2 with protein P0. However, the interaction is stronger with the P1/P2 proteins than with P0 in the two-hybrid assay. This interaction improves using the 100-amino-acid-long C-end of P0 and is even higher with the last 50 amino acids. The data indicate a specific association of P1alpha with P2beta and of P1beta with P2alpha rather than the dimerization of the acidic proteins found in prokaryotes. In addition, they suggest that stalk assembly begins by the interaction of the P1 proteins with P0. Moreover, as functional interactions of the complete P0 were found to increase using protein fragments, the data suggest that some active sites are exposed in the ribosome as a result of conformational changes that take place during stalk assembly and function.  相似文献   

19.
Abstract.  Phalangogonia Burmeister is revised and now includes eight species: P . dispar Ohaus, P . jamesonae , sp.n., P . lacordairei Bates, P . obesa Burmeister, P . parilis Bates, P . punctata Franz, P . ratcliffei , sp.n. and P . sperata Sharp. Phalangogonia debilidens Ohaus is placed in synonymy with P . sperata . Lectotypes are designated for the following nominal species: P . dispar Ohaus, P . lacordairei Bates, P . parilis Bates and P . championi Bates. Neotypes are designated for: P . obesa Burmeister, P . sperata Sharp, P . stipes Sharp and P . debilidens Ohaus. A cladistic analysis of the species of Phalangogonia was executed using thirty-two morphological characters of adults.  相似文献   

20.
The Saccharomyces cerevisiae ribosomal stalk is made of five components, the 32-kDa P0 and four 12-kDa acidic proteins, P1alpha, P1beta, P2alpha, and P2beta. The P0 carboxyl-terminal domain is involved in the interaction with the acidic proteins and resembles their structure. Protein chimeras were constructed in which the last 112 amino acids of P0 were replaced by the sequence of each acidic protein, yielding four fusion proteins, P0-1alpha, P0-1beta, P0-2alpha, and P0-2beta. The chimeras were expressed in P0 conditional null mutant strains in which wild-type P0 is not present. In S. cerevisiae D4567, which is totally deprived of acidic proteins, the four fusion proteins can replace the wild-type P0 with little effect on cell growth. In other genetic backgrounds, the chimeras either reduce or increase cell growth because of their effect on the ribosomal stalk composition. An analysis of the stalk proteins showed that each P0 chimera is able to strongly interact with only one acidic protein. The following associations were found: P0-1alpha.P2beta, P0-1beta.P2alpha, P0-2alpha.P1beta, and P0-2beta.P1alpha. These results indicate that the four acidic proteins do not form dimers in the yeast ribosomal stalk but interact with each other forming two specific associations, P1alpha.P2beta and P1beta.P2alpha, which have different structural and functional roles.  相似文献   

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