共查询到20条相似文献,搜索用时 15 毫秒
1.
H. Ettl 《Protoplasma》1964,59(2):298-309
Zusammenfassung Eine coccale Grünalge, die Korschikoff alsActinochloris sphaerica bezeichnete, wird eingehend nach dem Zellbau untersucht und nachgeprüft. Die polyenergiden Zellen mit bedeutendem Größenwachstum, das besondere Pyrenoid, pulsierende Vakuolen und die behäuteten,Chlamydomonas-ähnlichen Zoosporen rechtfertigen die Aufstellung einer selbständigen Gattung und Familie innerhalb derTetrasporales. Nomenklatorische und systematische Probleme vonRadiosphaera Snow,Macrochloris Korsch. undActinochoris Korsch. werden teilweise gelöst. Es wird festgestellt, daßActinochloris einerseits undRadiosphaera mitMacrochloris andererseits zwei verschiedene Gattungen sind, die zu unterschiedlichen Organisationstypen gehören. 相似文献
2.
Kahane S Dvoskin B Mathias M Friedman MG 《Applied and environmental microbiology》2001,67(10):4789-4795
Simkania negevensis, a novel microorganism belonging to the family Simkaniaceae in the order Chlamydiales, has an intracellular developmental cycle during which two morphological entities, elementary bodies (EB) and reticulate bodies (RB), are seen by electron microscopy. Rates of seropositivity to the organism are high in certain population groups, and S. negevensis has been associated with respiratory illness in humans. This study reports for the first time the ability of S. negevensis to survive and grow inside Acanthamoeba polyphaga in addition to its known ability to grow in cell cultures of human or simian origin. Infectivity of S. negevensis and growth in amoebae were monitored by immunoperoxidase assays. Long-term persistence and exponential growth of S. negevensis in amoebal trophozoites were demonstrated by infectivity assays and by electron microscopy. EB and dividing RB of S. negevensis were observed within inclusion bodies inside A. polyphaga. When S. negevensis-infected A. polyphaga amoebae were exposed to adverse conditions resulting in encystation of the amoebae, several possible outcomes were observed: cysts containing both normal amoebic cytoplasm and S. negevensis; cysts in which S. negevensis cells were relegated to the space between cyst walls; and cysts containing S. negevensis, but apparently lacking amoebal cytoplasm. S. negevensis within dried amoebal cysts was capable of long-term survival. The possibility that amoebae may have a role in natural transmission of S. negevensis needs to be investigated. 相似文献
3.
Berit Asmund 《Hydrobiologia》1968,31(3-4):497-515
Summary The Synura species found in samples from a variety of freshwater habitats in Alaska are identified by electron microscope studies of their scales. Synura petersenii f. macracantha Petersen & Hansen and Synura spinosa f. curtispina Petersen & Hansen are raised to specific rank. Synura petersenii f. praefracta n. f., Synura curtispina f. reticulata n. f., and Synura echinulata f. leptorrhabda n. f. are described. Electron micrographs of some scales belonging to undesignated formae are given.Some remarks on the ecology of the Synura species are given.
Zusammenfassung Synura Arten, die in Proben aus verschiedenen Süßwasser-Lokali-täten in Alaska gefunden werden sind, werden durch elektronenmikroskopische Untersuchungen ihrer Schuppen beschrieben. Zwei Formen, Synura petersenii f. macracantha Petersen & Hansen und Synura petersenii f. curtispina Petersen & Hansen, werden zur Rangstufe der Arten erhoben. Zwei neue Formen, Synura petersenii f. praefracta and Synura curtispina f. reticulata, werden beschrieben.Elektronen-mikroscopische Abbildungen einiger Schuppen, die von unbeschriebenen Formen herrühren, werden gegeben.Einige Anmerkungen über die Ökologie der Synura-Arten werden gemacht.相似文献
4.
A. O. SEGUN 《The Journal of eukaryotic microbiology》1971,18(2):313-317
SYNOPSIS. 30 acephaline gregarines, including 4 new species, were identified and described from the perivisceral coelom and vesiculae seminales of 13 British earthworm species. The newly described monocystids were Apolocystis megagranulata n. sp. and Nematocystis dendrobaenae n. sp. from Dendrobaena rubida f. subrubicunda and D. mammalis, Monocystis mammaliae n. sp. from D. mammalis, and Zygocystis ictericae n. sp. from Allolobophora icterica f. typica. These 3 earthworm hosts have not been previously examined for monocystids in Britain. 相似文献
5.
S. -J. Yin W. F. Bosron T. -K. Li K. Ohnishi K. Okuda H. Ishii M. Tsuchiya 《Biochemical genetics》1984,22(1-2):169-180
Liver homogenate-supernatants from most Japanese exhibit an atypical pH optimum for ethanol oxidation at pH 8.8 instead of 10.5, the typical pH-activity optimum. It has been proposed that atypical livers contain alcohol dehydrogenase isozymes with 2 subunits while typical livers contain isozymes with 1 subunits, both produced by the ADH
2 gene. Because it is difficult to differentiate the atypical ADH2 2-2 phenotype from the ADH2 2-1 phenotype by starch gel electrophoresis, an agarose isoelectric focusing procedure was developed that clearly separated the atypical Japanese livers into two groups, A1 and A2. The isozymes in A1 and A2 livers were purified. Type A1 livers contained a single isozyme with an atypical pH-rate profile; it was designated 22. Three isozymes were isolated from A2 livers, two of which corresponded to 11 and 22. A third, absent from the typical and the atypical A1 livers, had an intermediate mobility; it was designated 21. Type A1 livers are, therefore, the homozygous ADH2 2-2 phenotype, and type A2 livers, the heterozygous ADH2 2-1 phenotype. The ADH2 2-2 phenotype was found in 53% of 194 Japanese livers, and the ADH2 2-1 phenotype, in 31%. Accordingly, the frequency of ADH
2
2
was 0.68.This study was supported by U.S. Public Health Service Grant AA 02342. 相似文献
6.
A. V. Voylokov F. T. Fuong V. G. Smirnov 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,87(5):616-618
Segregation for self-fertility has been studied in progenies from the crosses of self-sterile (SS) plants with interline hybrids obtained by a diallel scheme of pollinations between seven self-fertile (SF) lines (nos. 2–8) and with F1 (SS plant x SF line) hybrids. All the offspring families from the SS plant x F1 (SS plant x SF line) crosses demonstrated a 1SF1SS segregation. The crosses of SS plants with some interline hybrids gave only self-fertile plants, whereas the crosses with other interline hybrids gave a segregation of 3SF:1SS expected in the case of digenic segregation. The data obtained permitted us to identify three different S loci (S1, S2, S5) and to estimate the genotypes of self-fertile lines for their Sf alleles: lines 5, 6, 7 and 8 are S1f/S1f S2n/S2n S5m/S5m, line 4 is S1n/S1n S2f/S2f S5m/S5m, and lines 2 and 3 are S1n/S1n S2m/S2m S5f/S5f(Sn, Sm designate active alleles of the incompatibility genes). The identification of the particular S gene which is presented by the Sf allele in each line has been made on the basis of our data concerning the linkage of the Sf mutation with isozyme markers of particular rye chromosomes, which is reported in an accompanying paper. 相似文献
7.
Anna Dyduch-falniowska 《Aquatic Ecology》1982,16(2-3):123-132
Summary From September 1979 to October 1980 in two types of biotopes (in the stream at Kali and in the Biaa Przemsza River near Jaroszowiec, southern Poland)P.amnicum, P.milium, P.subtruncatum, P.nitidum, P.personatum, P.casertanum andP. sp.non det. were found.P.amnicum was accepted as an indicator species for the river community, andP.milium for the stream. The irregular changes of species composition of the sphaeriid community in the stream at Kali are rather accidental and the only temporary occurrence ofP.nitidum, P.personatum andP. sp.non det. in the Biaa Przemsza River might be connected with seasonal migration.The dominance structure of thePisidium community in the stream agrees with the model described by CONNELL (1977) for the communities of large sedentary animals and plants. The dominance relations in the river community are similar to the situation described by CONNELL (1977) as characteristic for small lakes and islands.The density of the Sphaeriidae on the chosen habitat in the Biaa Przemsza River oscillated between 300 and 3.300 ind./m2 and it reached almost 130.000 ind./m2 in the stream at Kali.The SHANNON-WIENER's diversity index (H) and that of equitability or evenness of species abundances (J) had low values during the whole period of investigation.This study was performed as part of the Problem MRII/15 of the Polish Academy of Sciences. 相似文献
8.
Phialophora gregata nuclear (n) DNA was characterized by physical methods. The nDNA of f.sp.adzukicola was shown to be larger than that of f.sp.sojae, 2.9 and 2.1 × 1010 Da, respectively. The amounts of repetitive sequence and AT-rich region in the nDNA were also larger in f.sp.adzukicola than f.sp.sojae. These results indicate that the nuclear genome organization of the two formae speciales is differentiated. 相似文献
9.
Probir Chatterjee 《Hydrobiologia》1976,49(2):171-174
The paper deals with cytotaxonomic studies of three forms ofChara braunii-f.coromandelina (n = 14), f.schweinitzii (n = 14) and f.kurzii (n = 28) from West Bengal (India). An improved technique involving the use of a pretreating agent permitted a detailed analysis of the karyotypes of the three taxa studied. It has been concluded that structural alterations of chromosomes and polyploidy are associated with evolution of phenotypic differences in theChara braunii complex. The phylogenetic status ofChara braunii in the light of the present investigation is discussed. 相似文献
10.
Eulechriops argyrosoman. sp. (Curculionidae: Conoderinae: Lechropini) and Geratozygops platysoman. sp., Geratozygops stenosoman. sp. and Geratozygops arsinotusn. sp. (Curculionidae: Conoderinae: Zygopini) are described from Dominican amber. The small size, nearly parallel sides of the pronotum and silvery sheen distinguish Eulechriops argyrosoma from extant members of the genus, which have not been recorded from Hispaniola. Size and rostral and pronotal characters separate the three Geratozygops species from the single species (Geratozygops atropos) previously described from Dominican amber.http://www.zoobank.org/urn:lsid:zoobank.org:pub:89BC7F43-6C1A-4A6A-839B-CE94C7F6F140 相似文献
11.
P. R. Baverstock C. H. S. Watts Jane T. Hogarth A. C. Robinson Julia F. Robinson 《Chromosoma》1977,61(3):227-241
A total of 219 wild caught specimens representing 12 of the currently recognised 13 species and subspecies of Australian Rattus have been karyotyped. No two species possessed karyotypes in common, most species and several subspecies differing markedly in chromosome number. While the diploid number varied from 2n=32 to 2n=50, the fundamental number (FN) varied only from 60 to 62, suggesting that Robertsonian rearrangements have played a major role in karyotypic evolution in the group. — Karyotypically the Australian species of Rattus fall into two groups. — the R. lutreolus group and the R. sordidus group. Of the karyotypic forms encountered in the former group, that of R. lutreolus is probably most ancestral because it is identical to that of many Asian species of Rattus. Other karyotypic forms in the R. lutreolus group can be derived as follows: That of (1) R. tunneyi tunneyi and R. t. culmorum by a single fixed pericentric inversion; (2) R. fuscipes fuscipes, R. f. greyi, R. f. assimilis and R. f. coracius by two fixed fusions; (3) R. leucopus cooktownensis by three fixed fusions; and (4) R. leucopus leucopus by four fixed fusions. Of the R. sordidus group, R. s. villosissimus may possess the most ancestral karyotype with 2n=50 (FN=60), from which R. s. colletti (2n=42; FN=60) is derived by four fusions and R. s. sordidus (2n=32; FN=60) by nine fusions, four of which appear to be homologous with those R. s. colletti. — The karyotypic data are in accord with Taylor and Horner's (1973) suggestions that (1) R. t. tunneyi and R. t. culmorum belong to one species; (2) R. lut. lutreolus and R. lut. velutinus belong to one species; (3) R. leu. leucopus and R. leu. cooktownensis belong to one species and (4) R. f. fuscipes, R. f. greyi, R. f. assimilis and R. f. coracius belong to one species. However, the large karyotypic difference between R. s. sordidus and R. s. colletti and R. s. villosissimus may indicate that these groups belong to different biological species. — Supernumerary or B-chromosomes were found in R. f. assimilis and R. t. tunneyi. A single R. t. culmorum was heterozygous for a centric fusion. 相似文献
12.
K. H. Rechinger 《Plant Systematics and Evolution》1982,141(1):81-84
Saponaria stenopetala sp.n. in Eastern Afghanistan is close toS. pachyphylla
Rech. f. andS. subrosularis
Rech. f.—The nearest allies ofS. makranica sp.n. from Western Pakistan and Southeastern Iran areS. kermanensis
Bornm. andS. floribunda (Kar. & Kir.)Boiss.
Flora Iranicae praecursores 36–37. — Praecursores praecurrentes in Pl. Syst. Evol.139, 313–317 (1982). 相似文献
13.
Hirosumi Fujishima 《Journal of plant research》1984,97(2):137-150
The karyotypes of four taxa in theIxeris dentata complex collected from Mt. Ishizuchi were investigated.I. dentata subsp.dentata var.dentata f.dentata had 2n=21 in all the examined individuals and its karyotypes were classified into four different types. Var.dentata f.amplifolia showed 2n=21 in all individuals and had three different karyotypes.I. dentata subsp.dentata var.albiflora showed 2n=21 and two different karyotypes.I. dentata subsp.alpicola showed three different karyotypes with 2n=21 and four different ones with 2n=28.
Judging from the results of the karyotype analyses, the morphological variation of chromosomes in theI. dentata complex is assumed to be in the process of increasing asymmetry in the shape of chromosomes. Following Levitzky's principle,
it can be said that the a-, b-, and c-chromosomes exist in different advanced stages in the process of chromosome variation.
The c-group chromosomes are at the most advanced stage in morphological variation, the b-group in the second and the a-group
in the least advanced stage.
The above-mentioned structural diversity of chromosomes may be related to apomictic reproduction of theI. dentata complex. 相似文献
14.
We compared plerocercoids of Schistocephalus Creplin, 1829 from Cottus gobio (n = 57) and Gasterosteus aculeatus f. semiarmatus (n = 45) from the River Utsjoki, Finland, taken only from single worm infections. Segment numbers in the two populations were distinct (G. aculeatus range 55–107, average 74 (SE 1.66), median 73; C. gobio range 122–189, average 146 (SE 1.78); median 144). The mean difference between populations, 71.47, t = 28.76 with 100 degrees of freedom, two-tailed p value <0.001, was considered extremely significant. Amplification of microsatellite loci that were originally designed for Schistocephalus from G. aculeatus was positive for all larvae from G.␣aculeatus (n = 20), whereas in no plerocercoids from C. gobio (n = 20) were any of the six microsatellites amplified, indicating that plerocercoids from G. aculeatus and C. gobio were two distinct genetic populations of Schistocephalus. The material from C. gobio is described as S. cotti n. sp. Plerocercoids of the Palaearctic species of Schistocephalus are identified as follows: S. nemachili Dubinina, 1959 with 228–235 or more segments, specific to Barbatula spp. (Balitoridae); S. pungitii Dubinina, 1959 with 62–92 (usually 70–80) segments, specific to Pungitius pungitius; S. solidus (Müller, 1776) in two forms, one in G. aculeatus f. leiurus and f.␣semiarmatus, with 48–100 (usually 65–75) segments, and the other in G. aculeatus f. trachurus, with 99–138 (usually 112–122) segments; and S. cotti n. sp. with 103–189 (usually 130–159) segments, probably specific to cottids. Nearctic Schistocephalus were not considered owing to the uncertain status of some North American records. Some other species of Schistocephalus of highly doubtful status were briefly noted. Cross-infection experiments and molecular studies are recommended to further elucidate the interrelationships between the various species of Schistocephalus. 相似文献
15.
Małgorzata Łochyńska 《New Zealand journal of zoology.》2013,40(1):29-51
Abstract The juvenile stages and adults of two new Tasm anian crotoniid m ites Holonothrus minus‐culus sp. n. and H. glaesarius sp. n. are described and illustrated. Holonothrus minusculus sp. n. is similar to H. mitis Olszanowski, 1991 in body dimensions and because the openings of the opisthosomal gland are situated close to setae f2. It is similar to H. robus‐tus Olszanowski, 1991 in the length and structure of notogastral setae. H. glaesarius sp. n. is absolutely different from other known species of this genus and that is why it cannot be compared. 相似文献
16.
The Negev Desert is characterized by low soil-water availability and organic matter content, as well as important factors significantly influencing soil biological activity. In order to overcome the xeric environment, plant and soil biota have evolutionarily developed, over time, ecophysiological abilities that help them fulfill their biological role and function. Microorganisms are known as a major part of the ecosystem's total biomass and play an important role in decomposition processes and the nutrient cycle. Perennial shrubs have been found to play an important role as organic matter suppliers and as a physical barrier prolonging biological activity of microbial communities. Soil samples were collected monthly, from November 2006 to November 2007, from a 0 to 10-cm depth under the canopies of Reaumuria negevensis and from open areas (control) in order to evaluate abiotic components and microbial variables on a temporal basis. H' values, evenness, and β diversity (S?rensen's similarity) were determined by a molecular method based on sequencing. Water availability, organic matter content, and total soluble nitrogen were higher in soil samples collected in the vicinity of R. negevensis than in samples collected in open areas. Our study also indicated that, in spite of the similarity between H' values of soil samples collected in the vicinity of R. negevensis and the open area, a low percentage of similarity was found between the soil bacterial populations. These results support the hypothesis that distribution of resources in the environment under R. negevensis shrubs varies in space and time and also influences soil microbial diversity and the abiotic environmental role. 相似文献
17.
Summary The plasmids pSC138 and pML31 each contain the EcoRI-generated f5 replicator fragment of the conjugative plasmid F in addition to an EcoRI fragment encoding antibiotic resistance: ampicillin resistance derived from Staphylococcus aureus in pSC138 and kanamycin resistance from Escherichia coli in pML31. We have mapped one HindIII and two BamHI restriction sites in the f5 region of these plasmids and one HindIII site in the antibiotic resistance region of each plasmid. The HindIII site in the Km region of pML31 occurs in the kan gene whereas the HindIII site in the Ap region of pSC138 appears to occur in an area important for the regulation of -lactamase production.By means of in vitro recombinant DNA manipulation of plasmids pML31 and pSC138, we have shown that 1.9x106 daltons of the 6.0x106 dalton f5 fragment can be deleted without disrupting plasmid stability. In addition, we have used these same techniques to isolate a novel F-controlled Ap plasmid cloning vehicle which contains a single restriction site for each of the enzymes EcoRI, HindIII, and BamHI. This cloning vehicle has been linked via either its EcoRI or HindIII site to a ColE1 plasmid replicon to yield stable recombinants. 相似文献
18.
T. Koŀek J. Dmochowska-Gŀadysz A. Siewiński 《Applied microbiology and biotechnology》1992,37(6):762-764
Summary A culture of Aphanocladium album enantiospecifically reduces the carbonyl groups in (±)-8,14-seco-4,9(11)-androstadiene-3,14,17-trione only in the five-membered ring. In the 10S enantiomer only one of the two carbonyl groups at C-14 or C-17 is reduced, mainly to the corresponding alcohol, whereas in the 10R enantiomer both carbonyl groups are reduced. Chromatographic separation of optically active products and their chemical oxidation lead to the formation of enantiomers of the substrate: (-)-(10S)-trione [60% enantiomeric excess (ee)] and (+)-(10R)-trione (66% ee). The ,-unsaturated ketone in ring A remains unchanged.Part XXXII of the series Biotransformations
Correspondence to: A. Siewiski 相似文献
19.
Yamaguchi T Yamazaki T Inoue M Mashida C Kawagoe K Ogawa M Shiga S Nakagawa Y Kishimoto T Kurane I Ouchi K Ohzeki T 《FEMS immunology and medical microbiology》2005,43(1):21-27
Simkania negevensis has been associated with bronchiolitis in infants and community-acquired pneumonia in adults. Reports of exposure to this microorganism are only available from Israel, North America and Western Europe. Currently, no standard method for diagnosis of S. negevensis infection has been established nor have prevalence rates been shown in Japan. For the first time we demonstrated the ability of the microimmunofluorescence (MIF) test to detect S. negevensis-specific immunoglobulin G and exposure to S. negevensis in Japan. The positive rate in healthy volunteers was 4.3% (25/588), with rates increasing with age. Results indicate the usefulness of the MIF test as a serological method for detecting S. negevensis-specific antibodies. A standard serological test for infection with S. negevensis is needed. 相似文献
20.
M. Iranshahr 《Plant Systematics and Evolution》1979,132(1-2):149-152
Sclerorhachis rechingeri
Iranshahr, sp. n., from N. Khorasan is closely related to the Afghanistan speciesS. caulescens (Aitch. & Hemsl.)Rech. f. andS. polysphaera
Rech. f. It differs from both in the thicker and woolly collar and the much larger capitulum.Vorarbeiten zuK. H. Rechinger, Flora Iranica, Nr. 21. 相似文献