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1.
Zusammenfassung Beim ThermometerhuhnLeipoa ocellata tragen die Partner eine Paares ein Rufduett vor. Der Anteil des besteht aus einer Rufreihe, die sich aus einer Folge von 2–7 identischen, zweisilbigen Rufen zusammensetzt. Das trägt einen einzelnen, obertonreichen und langgezogenen Ruf vor. Sowohl der Ruf des als auch die Rufreihe des wird in Serien vorgetragen. Innerhalb einer solcher Ruf- bzw. Rufreihenserie können mehrere Duette auftreten. Die Rufe sind jedoch nicht ausschließlich an das Duett gebunden. Die Variabilität im Aufbau des Duetts äußert sich im Zeitpunkt des Einsatzes des antwortenden Vogels, in der Anzahl der -Rufe während des Duetts und in der Anzahl der Einheiten, aus denen sich der Duettanteil des zusammensetzt. Das beginnt signifikant häufiger als das eine Serie, in der ein oder mehrere Duette vorkommen. Ebenso ist es häufiger der Initiator des ersten in dieser Serie liegenden Duetts. Das Duett dient wohl hauptsächlich zur Festigung des Zusammenhalts zwischen den Paarpartnern. Es erfüllt jedoch von seinen physikalischen Eigenschaften her auch die Bedingungen, die für ein territorial wirksames Signal gelten.
Structure, variability and possible functions of duetting in the Mallee FowlLeipoa ocellata
Summary In the Australian Mallee Fowl,Leipoa ocellata, both and of a pair are involved in a call duet. The part of the consists of a sequence of 2–7 identical two-syllable calls. The contributes a single long-drawn-out call rich in harmonics. The call of the as well as the call sequence of the are presented in series. Within a series of calls () or call sequences () several duets can occur. The respective vocalizations, however, do not exclusively occur during the duet.The variability in the details of the duet expresses itself in the lag period after which the mate responds, in the number of -calls during the duet, and in the number of calls within the call sequence of the . The begins a series during which one or several duets occur significantly more frequently than the . The circumstances under which duetting occurs indicate that duet calling mainly serves to maintain the pair bond. Moreover, due to its physical characteristics the duet also seems to be suited to serve as a territorial signal.
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2.
Summary During the third leg of the European Polarstern Study (EPOS leg 3) in the austral summer season 1989, benthic macrofaunal communities were sampled from the Elephant Island area (61° southern latitude) and from Kapp Norvegia (71° southern latitude) to Halley Bay (75°30 southern latitude) using a commercial bottom trawl and an Agassiz trawl. Thirty-six trawl samples from a depth range of about 200–2,000 m were considered, with most of the samples being from the shelf and upper slope. Multivariate analysis techniques (clustering and TWIN-SPAN) discriminated between an eastern and a southern community in which parallel subgroups can be distinguished at increasing distance from the ice shelf.Data presented here were collected during the European Polarstern Study (EPOS) sponsored by the European Science Foundation  相似文献   

3.
Chloroplast DNA restriction fragment length polymorphisms have been used to reconstruct the maternal phylogeny of all the known taxa in the small neotropical legume genusLeucaena. Three major plastome clades were recognized, but these did not conform with relationships between the taxa proposed on other characters from morphology, cytology or hybridization. The maternal parentage of tetraploids within the genus has been proposed. Evidence for introgression was found between diploidL. diversifolia and tetraploidL. diversifolia. The implications of these results for the origin of the cultivated taxa are discussed.  相似文献   

4.
Summary The micropylar apparatus (MA) inDrosophila melanogaster (Diptera: Drosophilidae) is a 25 m long protrusion on the anterior pole of the eggshell, and it contains the 0.8 m wide micropylar canal through which the spermatozoon penetrates the eggshell. The canal terminates in the paracrystalline structure thus forming the pocket. The MA is secreted during oogenesis by the micropylar follicle cells (border cells and peripheral cells). Morphogenesis of the micropylar canal starts before stage 11A, when two of the border cells form two thin extensions containing microfilaments and penetrate the paracrystalline structure. Microtubules found at the base of the extensions participate in the formation of two projections. Adjacent follicle cells secrete the chorionic part of the MA, whilst the two projections elongate and twist during stages 12 and 13. Microtubules run parallel to the long axis of the projections and probably are related to cellular elongation during the formation of the projections. The paracrystalline structure is composed of lamellae having a periodicity of about 50 nm, which is maintained possibly due to the lateral fibrils connecting the lamellae. These lamellae consist of small fragments secreted during stages 10–11 by the border cells. The paracrystalline structure and the spongy vitelline membrane are condensed after egg maturation.  相似文献   

5.
O. Kiermayer  U. B. Sleytr 《Protoplasma》1979,101(1-2):133-138
Summary Cells ofMicrasterias denticulata Bréb. at the stage of secondary wall formation have been studied by freeze-etching. It was found that the plasma membrane exhibits oval areas in which arrays of membrane particles occur. These particles form rosettes which are arranged in a hexagonally ordered lattice with a center to center spacing of 25 nm. Nearly the same periodicities can be found between microfibrils. It is concluded that the rosettes probably together with the thickened area of the plasma membrane below them represent the apparatus for the production and orientation of microfibrils. The hypothesis suggesting the incorporation of membrane templates functional in microfibril formation, originally advanced byKiermayer andDobberstein (1973) has received further support.  相似文献   

6.
Summary The distribution and ultrastructure of serotonin- and dopamine-immunoreactive (5-HTi and DAi) neurones have been investigated in the terminal ganglion of the cricket, Acheta domestica, using a pre-embedding chopper technique. Special attention has been paid to the immunoreactive structures in the neuropil. 5-HTi structures are extensively distributed and densely packed throughout the 5 neuromeres of the terminal ganglion and originate from several interneurones and efferent neurones. In contrast, DAi fibres are distributed sparsely although they extend to all neuromeres of the ganglion and originate from 6 interneurons only. For both 5-HTi and DAi neurones characteristic axonal projections and branching patterns can be distinguished. The 5-HTi axons exhibit rich varicose arborizations, whereas DAi neurones possess fewer varicosities in the neuropil. Electron microscopy shows that 5-HTi varicosities contain small ( 60 nm) and large ( 100 nm) agranular vesicles, and large ( 100 nm) granular vesicles, whereas in DAi varicosities small ( 60 nm) agranular and large ( 100 nm) granular vesicles are seen. Both 5-HTi and DAi varicosities form synaptic contacts. We conclude that both serotonin and dopamine may be used as neurotransmitters in the terminal ganglion of the cricket.Fellow of the Alexander von Humboldt-Stiftung  相似文献   

7.
Transformation ofEscherichia coli strains with the recombinant plasmid, prepared by shot gun cloning with pBR322 and containing the geneasd, the structural gene of aspartate--semialdehyde dehydrogenase, results in an increase in specific activity of 65-fold of the enzyme in crude extracts. Approximately 60 mg of pure enzyme may be obtained from 10 g of transformed cells (wet weight) in a simplified purification procedure. The molecular weight, amino acid composition, and kinetic properties of the enzyme appear to be the same as previously reported, and the first 36 amino acids of the N-terminal sequence have been determined.  相似文献   

8.
Zusammenfassung Langerhanssche Inseln des Frosches Rana ridibunda wurden nach Osmiumtetroxyd-, Glutaraldehyd- und Acroleinfixierung elektronenmikroskopisch untersucht. Nach ausschließlich Aldehydfixierung und Nichtanwendung einer Kontrastierungsmethode fehlt den Sekretgranula der Inselzellen ihr bekannter positiver Kontrast; sie können sogar im negativen Kontrast erscheinen. B-Zellen besitzen runde und nadeiförmige Sekretgranula neben anderen Zelleinschlüssen (Lipidtropfen, lysosomenartige Einschlüsse, Vakuolen, glykogenartiges Material) und zeigen meist eine bipolare Zytoplasmaorganisation. Golgiapparat und Ergastoplasma sind relativ spärlich entwickelt. Während die B-Zellmorphologie keine starke Abhängigkeit von der Art der Fixierung zeigte, erwies sich das Bild der Typ IIundTyp HI-Zellen als stark fixationsabhängig. So scheinen chromophobe Zellen, d.h. Zellen, die leere Bläschen an Stelle der Sekretgranula enthalten, bei Osmiumfixierung aus Typ IIZellen und bei Acroleinfixierung aus Typ III-Zellen zu entstehen. Chromophobe Zellen wurden nach Glutaraldehydfixierung niemals beobachtet. Die bläschenreichen Zellen erscheinen den D-Zellen verschiedener Autoren verwandt zu sein. Das Bild dieser Elemente wird als Fixationsartefakt betrachtet. Ein eigentlicher chromophober Zelltyp scheint demnach in den Langerhansschen Inseln des Frosches nicht zu existieren. Die hellen Zellen der Lichtmikroskopie rekrutieren sich demnach aus verschiedenen Quellen, zu denen granulaarme Formen aller 3 Zelltypen und schlecht erhaltene granulareiche Formen der Typen II und III gehören.
Summary In a study on the fine structure of the endocrine pancreas in Rana ridibunda, osmium tetroxide, glutaraldehyde, and acrolein have been used as fixatives. After aldehyde fixation alone, without application of any further contrasting procedure, the secretory granules of the islet cells lack their known positive contrast and may show up even in negative contrast. B cells possess round and needle-like secretory granules together with other inclusions (lipid, lysosome-like, vesicular, glycogen-like) and mostly display a bipolar organisation. B cell Golgi apparatus and ergastoplasm are relatively sparse. Whilst B cell structures do not show much variation with the fixative employed, those of type II and type III cells do. Thus, chromophobe cells, i.e. cells containing empty vacuoles instead of secretory granules, seem to arise from type II cells with osmium tetroxide fixation and from type III cells with acrolein fixation. Chromophobe cells were never observed after glutaraldehyde fixation. They are likened to D cells of authors employing osmium fixation and are considered to be artifacts due to fixation. No chromophobe cell proper, therefore, seems to exist in the frog pancreatic islet and the clear cells of light microscopy should stem from several sources including agranular stages of the types B, II, and III and badly preserved granular stages of types II and III.


Durchgeführt mit dankenswerter Unterstützung durch den Schweizerischen Nationalfonds.

Zusatz bei der Korrektur. Forssmann, W. G., G. Siegrist, L. Orci, L. Girardier, R. Pictet und Ch. Roullier berichteten [J. Microscopie 6, 279–304 (1967)] über elektronenmikroskopische Beobachtungen an verschiedenen Organen nach Perfusionsfixierung. Die in der vorliegenden Studie nach Immersionsfixierung erhobenen Befunde mit solchen nach Perfusionsfixierung zu erhebenden zu vergleichen, erscheint uns wesentlich.  相似文献   

9.
Summary Six juvenile and adult patients with progressive neurological diseases and -galactosidase deficiency were reported. Any diseases known to date were denied. These cases together with ten case reports in the literature were reviewed and were classified into three groups from clinical and biochemical points. Group 1 patients were characterized by progressive ataxia and myoclonus with gargoyle changes and macular cherry-red spots. In this syndrome -galactosidase activity seems to be secondarily affected by other biochemical defects. A group 2 patient showed similar neurological manifestations without gargoyle changes or macular cherry-red spots. Patients with these clinical features not associated with -galactosidase deficiency have also been described in the literature. Group 3 patients had progressive pyramidal and extrapyramidal disease without gargoyle changes or macular cherry-red spots. These cases may represent juvenile and adult type GM1-gangliosidosis. Accumulation of GM1 has not yet been demonstrated.  相似文献   

10.
A new fluorometric assay was developed for the measurement of -glutamyl transpeptidase (-GTP). The assay utilizes as a substrate the synthetic compound 7--glutamylamido-4-methyl coumarin which is cleaved by -GTP to yield the highly fluorescent product 7-amino-4-methyl coumarin. Optimal excitation and emission wavelengths for the assay are 345 nm and 470 nm, respectively, and the sensitivity of the assay is greatly enhanced by the high-pressure liquid chromatographic separation of the product from the substrate. The assay is minimally 25 times more sensitive than the conventional spectrophotometric assay and permits analysis of as little as 5000 cultured cells of neuronal and glial origin. Analysis of a variety of cultured cells of neuronal and glial origin with this assay suggests that -GTP is largely present in glia and to a lesser extent in neurons.  相似文献   

11.
Summary Ultrastructural analysis of the mature viable unhydrated pollen of maize,Zea mays from dehiscent anthers shows that the sperm cells are physically distant, each bounded by an envelope comprising their own plasma membrane and the inner plasma membrane of the vegetative cell. The chondriome is unusual in containing one or more filamentous complexes, up to 12m in length appressed to the side of the sperm nucleus. The extensions at each end of the elongate sperm cells contain longitudinally-oriented arrays of endoplasmic lamellae. In a three-dimensional reconstruction of serial thin sections, there is a long J-shaped sperm, c. 35 × 5m and up to 1m in thickness, sited within pointed evaginations of the vegetative nucleus and a second shorter sperm c. 20 × 5m and up to 3.5m in thickness.Abbreviations PA-TCH-SP periodic acid-thiocarbohydrazide-silver proteinate - DAPI 4,6-diamino-2-phenylindole - SC sperm cell - Sn sperm nucleus - Ua-Pb Uranyl acetate-lead citrate staining - ER endoplasmic reticulum  相似文献   

12.
Summary Freeze-fracture studies were conducted on the membranes of normal cockroach hemocytes. The plasmalemma is asymmetric with the A fracture face containing 80–100 Å membrane intercalated particles at a concentration of 2500/2. The B fracture face contains 120–150 Å particles with a relatively low density (800/2). The nuclear envelope displays an asymmetry with the A fracture face containing 1500 particles/2 and the B face containing 300/ 2. No significant particle size differences were observed in nuclear envelope fracture faces. Two types of symmetric membranes were also found in these cells. Both A and B fracture faces of the membrane surrounding the numerous cytoplasmic inclusion bodies contain particle sizes and concentrations similar to the B face of the plasmalemma. A second type of symmetry was observed in cells apparently engaged in exocytosis. Vesicles (0.1 D) from this process were completely particle free on both fracture faces. Such particle free vesicles could be found in the cytoplasm, attached to the plasmalemma, or completely separated from the cell.Supported by a Pharmaceutical Manufacturers Association Foundation Fellowship.The author wishes to thank Ms. Annalena K. Charla for assistance in plate preparation, Dr. Julius Schultz and the Papanicolaou Cancer Research Institute for use of the freeze-etch device, and Dr. David Smith for the electron microscope facilities.  相似文献   

13.
Summary On exposure to high temperature of a temperature-sensitive RNA polymerase subunit (rpoC92) mutant of Escherichia coli, selective reduction was observed in the rate of synthesis of a group of proteins including RNA polymerase subunit. The finding that the synthesis of subunit but not subunit was specifically repressed in this mutant grown at non-permissive temperature indicates that the functionally intact RNA polymerase is required for the synthesis of subunits be coordinated. In addition, the assembly of newly synthesized RNA polymerase subunits was inefficient in this mutant at the steps where altered subunit was involved, and the unassembled enzyme subunits were rapidly and preferentially degraded. During recovery to non-restricted growth, the synthesis of both and subunits was transiently enhanced in parallel leading to recovery of the intracellular concentration of functional RNA polymerase.  相似文献   

14.
Maria Bokern  Dieter Strack 《Planta》1988,174(1):101-105
Protein preparations from cell suspension cultures of Chenopodium rubrum L. and petals of Lampranthus sociorum (L.Bol.) N.E.Br. (Mes.C.L.Bol.) catalyzed the formation of acylated betacyanins, i.e. celosianin I and II (p-coumaroyl-and feruloylamaranthins) and lampranthin I and II (p-coumaroyl- and feruloylbetanins), from 1-O-(p-coumaroyl)-and 1-O-feruloyl--glucoses as acyldonors and the respective acceptor molecules amaranthin (betanidin 5-O-sophorobiuronic acid = betanidin 5-O--[12]-glucuronosyl--glucoside) and betanin (betanidin 5-O--glucoside). The enzymes involved could generally be classified as 1-O-hydroxycinnamoyl--glucose:betanidinglycoside O-hydroxycinnamoyltransferases (EC 2.3.1.-).Abbreviations HCA hydroxycinnamic acid - HCA hydroxycinnamoyl (=hydroxycinnamic acid-ester moiety) - HPLC high-performance liquid chromatography - TLC thin-layer chromatography  相似文献   

15.
A protocol for high frequency adventitious shoot regeneration adventitious shoot regeneration from leaf explants of Rhododendron spp. has been developed. The highest percentage of regeneration and the greatest number of shoots were obtained when leaf explants were cultured on Anderson's medium containing 4.9 M IBA and 73.8 M 2iP. Genotypic variation was observed for adventitious shoot regeneration potential among the seven cultivars tested. Regeneration frequencies ranged from 0 to 96%. Lodestar had the highest rate of regeneration after 3 months of culture with 96% shoot regeneration and an average of 14 shoots per explant. Regenerated shoots were rooted in soil in about 2 months. This protocol should be useful in applying gene transfer techniques to Rhododendron improvement.Abbreviations IAA 1-H-indole-3-acetic acid - NAA 1-naphthaleneacetic acid - IBA 1-H-indole-3-butyric acid - 2,4-d 2,4-dichlorophenoxyacetic acid - BA 6-benzyladenine - 2iP N-(3-methyl-2-butenyl)-1-H-purine-6-amine  相似文献   

16.
A method for rapid and highly effective plant micropropagation from vegetative meristems was established for Aloe barbadensis Mill. Plant micropropagation was achieved culturing apices on medium containing 1.1 M 2,4-dichlorophenoxyacetic acid and 2.3 M kinetin for 15–30 days. High morphogenetic ability was maintained by transferring explants (after 60 days) on media containing 0.11 M 2,4-dichlorophenoxyacetic acid and 2.2 M 6-benzylaminopurine.  相似文献   

17.
In questa Nota I sono compresi i capitoli relativi alla letteratura sull'argomento, al piano delle ricerche, al materiale e alla tecnica impiegata, ai mutamenti di peso e di forma delle ossa inerti. Nella Nota II saranno esposte le modificazioni di struttura di 2 e di 3 ordine delle ossa immobilizzate e le conclusioni generali.  相似文献   

18.
Corynebacterium glutamicum effectively secretes L-glutamate when growing under biotin limitation. The secretion of glutamate was studied with respect to kinetic and energetic parameters: rate of glutamate uptake and efflux, specificity of transport, dependence of efflux on the energy state of the cell, concentration gradient of glutamate and ions, and membrane potential. By comparing these parameters when measured in biotin-limited, i.e. producer cells, and biotin-supplemented, i.e. non-producer cells, respectively, the following conclusions could be drawn: 1. The efflux of L-glutamate in C. glutamicum cannot be explained by passive permeation of this amino acid through the plasma membrane, as it has been assumed in the generally accepted model of glutamate secretion in biotin-limited cells. 2. It is unlikely that the efflux of glutamate occurs via an inversion of the glutamate uptake system. 3. Based on our results concerning the specificity and the kinetics of glutamate transport as well as the observed regulation phenomena, we conclude that secretion of glutamate in C. glutamicum occurs by a special efflux carrier system.Abbreviations dw dry weight - OD optical density - TPP tetraphenyl phosphonium bromide  相似文献   

19.
1,3-Fucosyltransferase solubilized from human liver has been purified 40 000-fold to apparent homogeneity by a multistage process involving cation exchange chromatography on CM-Sephadex, hydrophobic interaction chromatography on Phenyl Sepharose, affinity chromatography on GDP-hexanolamine Sepharose and HPLC gel exclusion chromatography. The final step gave a major protein peak that co-chromatographed with 1,3-fucosyltransferase activity and had a specific activity of 5–6 µmol min–1 mg–1 and anM r 44 000 deduced from SDS-PAGE and HPLC analysis. The purified enzyme readily utilized Gal1-4GlcNAc, NeuAc2-3Gal1-4GlcNAc and Fuc1-2Gal1-4GlcNAc, with a preference for sialylated and fucosylated Type 2 acceptors. Fuc1-2Gal1-4Glc and the Type 1 compound Gal1-3GlcNAc were very poor acceptors and no incorporation was observed with NeuAc2-6Gal1-4GlcNAc. A polyclonal antibody raised against the liver preparation reacted with the homologous enzyme and also with the blood group Lewis gene-associated 1,3/1,4-fucosyltransferase purified from the human A431 epidermoid carcinoma cell line. No cross reactivity was found with 1,3-fucosyltransferase(s) isolated from myeloid cells. Examination by Northern blot analysis of mRNA from normal liver and from the HepG2 cell line, together with a comparison of the specificity pattern of the purified enzyme with that reported for the enzyme expressed in mammalian cells transfected with theFuc-TVI cDNA, suggests a provisional identification ofFuc-TVI as the major 1,3-fucosyltransferase gene expressed in human liver.Died June, 1991  相似文献   

20.
High frequency fusion of plant protoplasts by electric fields   总被引:5,自引:0,他引:5  
Mesophyll cell protoplasts of Vicia faba were collected by dielectrophoresis in a highly inhomogeneous alternating electric field (sine wave, 5 to 10 V peak-to-peak value, 500 kHz, electrode distance 200 m). Under these conditions, the cells formed aggregates of two or three on the electrodes or bridges consisting of 4 to 6 protoplasts between the electrodes. This pearl chain arrangement of the cells was only stable for the duration of the applied field. By the additional application of a high single field pulse (square wave, 15 V, 50 s), it was possible to induce cell fusion within the aggregates or bridges. This electrically stimulated fusion of cells proceeded at room temperature and under physiological pH-conditions, without the use of chemical reagents, and gave a high yield. Smaller fused aggregates formed spheres within a few minutes. During the dielectrophoretically induced adhesion of the protoplasts to one another, the field strength must be chosen such that dielectric breakdown of the membrane is avoided, but at the same time, the strength of the subsequently applied single field pulse must be high enough to induce dielectric breakdown at the sites of contact between the protoplast membranes. From these results, one can conclude that in addition to close contact between membranes, the prerequisite for electrically stimulated cell fusion is dielectric breakdown which leads to changes in the membrane conductance, permeability, and probably fluidity.Presented at II Congress FESPP, Santiago de Compostela, Spain, 27.7.–1.8.1980, and Gordon Research Conference of Bioelectrochemistry, Tilton, New Hampshire, USA, 4.8.–8.8.1980  相似文献   

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