共查询到20条相似文献,搜索用时 15 毫秒
1.
Wolfgang von de Wall 《Journal of Ornithology》1963,104(1):1-15
Zusammenfassung Vorliegende Arbeit ist eine Weiterführung derLorenz'schen Bewegungsstudien an Anatinen aus dem Jahre 1941, fortgesetzt an Mischlingen zwischen den dort beschriebenen Arten. Die sich dabei ergebenden Befunde machten eine erneute Untersuchung der Elternarten notwendig. Außerdem wurden einige Arten beobachtet, deren Verhalten noch nicht untersucht worden war. Fragestellung und Begründung werden in der Einleitung gegeben.Im zweiten Abschnitt werden einige der vonLorenz gemachten Beobachtungen berichtigt. So zeigten einige der Kreuzungen mitbahamensis, daß die vonLorenz bei eben dieser Art als Kurzhoch-werden bezeichnete Bewegungsweise dem Ab-auf anderer Schwimmenten homolog ist. Ebenso ist die eine der beiden vonLorenz als Kurzhoch-werden bezeichneten Verhaltensweisen des Krickerpels als Ab-auf zu deuten. Der Gruß desflavirostre-Erpels wurde auch bei weiblichen Tieren gesehen. BeiAnas acuta wurde ein Kinnheben festgestellt, das sich in der Form stark vom Kinnheben beiplatyrhynchos unterscheidet. Als neue Verhaltensweisen wurden u. a. das Haltungannehmen und das Tendieren beimflavirostre-Erpel beschrieben.Im dritten Abschnitt werden einige Verhaltensweisen und ihre Funktion diskutiert und der Versuch gemacht, eine Motivationsanalyse zu geben.(Zeichnungen vonHermann Kacher) 相似文献
2.
N Nakada K Yoshinaga A Ishihama H Nagasawa-Fujimori 《Molecular & general genetics : MGG》1982,188(2):173-178
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
3.
Summary Ribosomal RNA (rRNA) genes of Saccharomyces cerevisiae are clustered in a DNA repeat unit of 5.9 megadaltons with the gene order 5S-18S-5.8S-25S rRNA (Nath and Bollon, 1977). By using two restriction endonucleases, EcoRII and HindII, which generate DNA fragments that span contiguous portions of two repeat units, we report that the rRNA gene clusters are tandemly repeated without the intervention of additional spacer DNA.The treatment of yeast DNA with the restriction endonucleases EcoRII and HindII result in the generation of 4 different DNA fragments that are of varying sizes and which hybridize with rRNA. The largest DNA fragments, 3.30 megadaltons in the case of HindII and 3.67 megadaltons in the case of EcoRII, encompass regions that code for the two opposite end regions of the 35S precuursor-rRNA. These two end regions are joined by a constant DNA segment of about 0.9 megadaltons in size of which a 0.08 megadalton segment codes for 5S rRNA. Since the 35S precursor-rRNA includes the 5.8S, 18S and 25S rRNA most of the repeat units containing the 4 rRNA coding genes in yeast are linked to each other contiguously without any intervening spacer DNA.A composite map of the DNA restriction fragments obtained by the action of the restriction endonucleases EcoRI, EcoRII, HindII and HindIII on the 5.9 megadalton repeat unit is presented. Some striking features concerning the location of the restriction sites are noted. Of the total 17 DNA restriction sites present on each repeat unit, 9 are located at or near the 3 transcribed spacer regions contained in the 5 megadalton DNA segment that codes for the 35S precursor-rRNA. The 3 transcribed spacer regions in the 35S precursor-rRNA include the two external transcribed spacer regions and an internal transcribed spacer region, the latter representing the 5.8S rRNA. 相似文献
4.
Poly(A)-containing 9S RNA from chick reticulocytes was electrophoresed on formamide-polyacrylamide gels. The molecular weight was determined to be 211 000±10 000 daltons. The RNA was separated into three different fractions with respect to molecular weight. These RNAs were translated in a wheat germ cell-free system. The lower molecular weight RNA directed up to 95% -chain synthesis, compared to 60% for the higher molecular weight RNA. This was accompanied by a relative increase for -chain synthesis with increasing molecular weight. It could also be shown by hybridization with labelled poly(U) that the average poly(A) length decreased from about 83 nucleotides for fraction I to 36 nucleotides for fraction III. Our results suggest that fractionation of avian 9 S globin mRNA by electrophoresis on formamide-polyacrylamide gels is dependent upon two parameters, namely differences in the lengths of the non-poly(A)-containing portion of the and mRNAs and differences in the poly(A) lengths. 相似文献
5.
Gerhard Haider 《Hydrobiologia》1973,41(1):57-76
180 rainbow trouts (Salmo gairdneriRich.), aged from 1 to 3 years, were examined for fluctuations, caused by age and season, by means of colour index (CI), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC).CI and MCH behave similarly. Both are increasing until the 2nd year and stay relatively constant thereafter. If the gender is not considered — there are no significant differences in the values of males and females — the CI increases from 1,4 in the first year over 1,6 to 1,7 in the age of 3 years, and the MCH increases from 44,4 over 52,6 , 56,8 , 58,1 to 55,5 .A seasonal periodicity of both indices could not be indicated on not-matured animals (F2) which were two summers of age. Only, the january values appeared increased — CI: 2, MCH: 68,3 — otherwise the CI varies between 1,8 and 1,7 and the MCH between 53,3 and 59,1 .The MCHC-values of the age groups examined vary between 24,4% and 27,3%. The values of the yearlings form an exception (19,8%). These values certainly are inexact and too low because of the small number of individuals checked (3).
Mit finanzieller Unterstützung durch die DFG.Institut für Siedlungswasserbau und Wassergütewirtschaft der Universitat Stuttgart Fischtoxikologische Arbeitsgruppe 相似文献
Mit finanzieller Unterstützung durch die DFG.Institut für Siedlungswasserbau und Wassergütewirtschaft der Universitat Stuttgart Fischtoxikologische Arbeitsgruppe 相似文献
6.
Dr. Franz Müller 《Planta》1961,57(4):463-477
Zusammenfassung Aus Blumenkohl (Brassica oleracea var.botrytis L.) wurden die darin enthaltenen Indolverbindungen nach vier verschiedenen Methoden extrahiert.Nach der papierchromatographischen und papierelektrophoretischen Aufgliederung der Extrakte aus Blumenkohlrosengewebe konnten insgesamt 13 mit Sprühreagentien färbbare Zonen nachgewiesen werden, bei denen es sich zum größten Teil um Indolderivate handeln dürfte. Hiervon wurden Tryptophan, -Indolylcarbonsäure, -Indolylessigsäure, -Indolylpropionsäure, -Indolylaldehyd und -Indolylacetonitril identifiziert.In den Blättern des Blumenkohls kommen im wesentlichen die gleichen Indolverbindungen wie in den Blumenkohlrosen vor.Die in den verschiedenen Entwicklungsstadien und Pflanzenteilen des Blumenkohls vorliegenden Mengen an -Indolylcarboxylsäure, -Indolylessigsäure und -Indolylpropionsäure wurden quantitativ bestimmt und untereinander verglichen; die Menge des jeweils vorhandenen -Indolylacetonitrils konnte aus methodischen Gründen nur relativ bestimmt werden.Bei der quantitativen Bestimmung konnte — bezogen auf das Frischgewicht — in den Blättern im Laufe der Ontogenie eine Zunahme im Gehalt an -Indolylcarboxylsäure, -Indolylessigsäure und -Indolylpropionsäure festgestellt werden. Beim -Indolylacetonitril-Gehalt der Blätter zeigte sich gleichfalls eine Zunahme während der Entwicklung; ausgewachsene Blätter von Pflanzen mit Rosen (Tabelle 3, Stadium 4) wiesen aber einen geringeren Gehalt an -Indolylacetonitril auf als die Blätter jüngerer Pflanzen (Stadium 1–3).Der Gehalt an -Indolylcarboxylsäure, -Indolylessigsäure, -Indolylpropionsäure und -Indolylacetonitril ist im Gewebe von Blumenkohlrosen wesentlich höher als in den anderen extrahierten Pflanzenteilen (Blätter, Blütensprosse und Blüten, unreife Früchte).Mit 1 TextabbildungErster Teil einer Dissertation der Naturwissenschaftlich-Philosophischen Fakultät der Justus Liebig-Universität, Gießen.Die Abkürzungen der Indolverbindungen sind auf S. 467 und in Tabelle 1 zusammengestellt. 相似文献
7.
Summary A ribosomal protein (L2) which binds to 23S rRNA was isolated from 70S ribosomes of several Bacillacease. It was shown by two-dimensional gel electrophoresis, molecular weight determination, amino acid analysis and immunological methods that this protein is homologous to the E. coli ribosomal protein L2 which also binds to 23S rRNA. In all Bacillaceae this protein L2 remains bound to 23S rRNA after extraction of ribosomal proteins with 4 M urea and 2 M LiCl, in contrast to E. coli. Immunological experiments demonstrated that the protein L2 of B. stearothermophilus undergoes a conformational change when it binds to 23S RNA.Paper No. 69 on Ribosomal proteins. Preceding paper is by Geisser et al., Molec. gen. Genet. 127, 129–145 (173) 相似文献
8.
Streptococci of serological groups N and D were found to belong to three different 23S ribosomal RNA (rRNA) homology clusters which are not closely related to each other. One cluster includes the group N streptococci:Streptococcus lactis, S. cremoris, S. diacetylactis, and, in addition, two lactobacilli, Lactobacillus hordniae andL. xylosus. The second one is composed ofStreptococcus faecium, S. durans, andS. faecalis with its subspecies. All are members of serological group D. The third group includes the group D streptococciStreptococcus bovis andS. equinus together withS. thermophilus andS. salivarius. DNA-DNA hybridization studies confirm the close genetic relationship within each of the rRNA homology clusters. 相似文献
9.
Summary In spite of the generally well-coordinated synthesis of RNA polymerase core enzyme subunits (, and ) in Escherichia coli, a situation was found during the growth transition from exponential to stationary phase in which this coordination was broken (the order of differential repression being ; Kawakami et al. (1979)). The present study indicates that, during a certain period of the growth transition, twice as much subunit is synthesized as subunit and the overproduced subunit accumulates as the assembly intermediate 2 complex, which is rapidly and preferentially degraded.Two independent factors, i.e., carbon source down-shift and oxygen depletion, were examined separately for their influence on the coordinated regulation of the synthesis of RNA polymerase subunits. The depletion of glucose added as a sole carbon source was accompanied by repression of the synthesis of all core enzyme subunits, while under the same conditions the differential rate of subunit synthesis increased. In contrast, the sudden ending of the oxygen supply resulted in specific repression of the synthesis of only and subunits but not of and subunits. The latter result may be explained by the autogenous repression of the rpoBC genes by a temporal increase in the amount of unused cytoplasmic RNA polymerase.Paper XI in this series is Kawakami and Ishihama (1980) 相似文献
10.
Leslie C. Eaton Jack S. Sevall Joe A. Fralick 《Molecular & general genetics : MGG》1979,175(2):121-127
Summary DNA-dependent RNA polymerase has been found to be preferentially released at 43° C from the folded nucleoids of an E. coli dnaA
ts mutant when compared with the same nucleoids at 30° C or with nucleoids of a dnaA
+ strain at either 30° or 43° C. The polypeptides released are identical in molecular weight with those of the and constituent polypeptides of the core enzyme of a known E. coli RNA polymerase. In addition, these polypeptides are precipitated by specific anti-RNA polymerase rabbit IgG. The implications of the interactions of RNA polymerase with the dnaA gene product are discussed. 相似文献
11.
Summary Intracellular bacteria belonging to two phylogenetically different groups of eubacteria were found in cultures of the freshwater dinoflagellatePeridinium cinctum (O. F. Müller) Ehrenberg isolated from the eutrophic lake Plußsee (Federal Republic of Germany). The phylogenetic relationships of the bacteria were studied with fluorochrome-conjugated oligonucleotides specific for archaebacteria, eubacteria, -, - and -proteobacteria, complementary to 16S rRNA and 23S rRNA sequences, respectively. The bacteria are members of the eubacterial - and -subgroups of proteobacteria. 相似文献
12.
Summary Human -galactosidase-deficient skin fibroblasts from a patient with generalized gangliosidosis (GM1-gangliosidosis type I) were treated with phage plac DNA, coding for Escherichia coli -galactosidase (-D-galactoside galactohydrolase, EC 3.2.1.23). New -galactosidase activity detected in cell extracts of phage DNA-treated GM1-gangliosidosis fibroblasts continued to vary considerably from one experiment to another. It behaved like the E. coli
z-gene product upon immunochemical and physicochemical investigation. In some experiments the antigenic behavior of resultant -galactosidase activity in plac DNA-treated cells resembled that of mutant E. coli -galactosidase. Among the factors and variables that may be responsible for the variation in the results obtained here and elsewhere, low physical binding between prokaryotic mRNA sequences and fibroblast ribosomal RNA could play a part connected with effective translation. This hypothesis is discussed under the aspect of a comparison of the ribosomal binding site of lac z mRNA with the 3-terminus of the eukaryotic 18s ribosomal RNA, which shows limited possibilities for base-pairing interactions.More extensive possibilities for forming Watson-Crick base pairs between their initiation site and the eukaryotic ribosomal binding site exist for other prokaryotic messengers, such as those of Q-replicase, f 1-coat protein, or UDPG-4-epimerase. 相似文献
13.
Metabolic fate of initiation factors after inhibition of protein synthesis in Escherichia coli 总被引:2,自引:0,他引:2
Lucienne Legault-Demare Claude Jeantet François Gros 《Molecular & general genetics : MGG》1973,125(4):301-318
Summary The metabolic fate of translation initiation factor after inhibition of protein synthesis by different means has been investigated. We have found a decay in initiation factor activity when protein synthesis is blocked by chloramphenicol but not during arginine starvation of PA1 (Rel–) or PA2 (Rel+) strains or during puromycin incubation. These results suggest that inactivation of certain initiation factors occurs when the regeneration of ribosomal subunits from polysomes is inhibited in the cells.Complementation experiments indicate that IF3 factor activity is preferentially affected during chloramphenicol treatment.Same preferential inhibition of IF3 activity seems to occur during in vitro incubation of crude IF. 70S ribosomes or 30S subunits protect this factor against the inactivation. Preliminary results seem tosuggest that ATP is implicated in this in vitro inactivation process. 相似文献
14.
In this paper we analyse a stochastic model for invertebrate predation taking account of the predator's satiation. This model approximates Holling's hungry mantid model when handling time is negligible (see Part I). For this model we derive equations from which we can calculate the functional response and the variance of the total catch. Moreover we study a number of approximations which can be used to calculate these quantities in practical cases in a relatively simple manner.List of Notation
a
rate constant of digestion
-
b
maximum of rate constant of prey encounter in the mantid
-
c
satiation threshold for search
-
c
satiation threshold for pursuit in the mantid
-
c
i
(w1/2(N- N)i)
-
expectation operator
-
f
rate of change of satiation during search
-
F
functional response: mean number of prey eaten per unit of time
-
g
rate constant of prey capture
-
h
probability generating function of N conditional on S = s times p
- H
probability generating function of N
- mi
1
-
n, N
number of prey caught
-
p
probability density of S
- pn
simultaneous probability (density) of N and S
-
q
probability of strike success
-
r
dummy variable in generating function
-
s, S
satiation
-
T
s
search time
-
T
d
digestion time
-
v
asymptotic rate of increase of var v
-
V
asymptotic rate of increase of var N
-
w
weight of edible part of prey
-
W
standard Wiener process
-
x
prey density
- z
(N{S = s}-N)p
-
rate constant of prey escape time maximum pursuit time
-
(v{S = + w
1/2}-v)
-
present time as a fraction of the time from the start to the end of the experiment
-
hazard rate of T
s
-
mean time between (downward) passages of S through c
-
v
w–1/2(N-)
-
edible prey biomass density
-
probability density of , number pi
-
parameter of Weibull distribution of T
s = (1/2acx(-g(c)))1/2
-
w–1/2(S -)
-
satiation in the guzzler approximation: solution to d/dt = f() + g(), (0)=S(0).
-
biomass functional response: wF
-
total biomass catch in the guzzler approximation: solution to d/dt = g(), (0) = 0 相似文献
15.
Robert E. Glass Michael Goman Laurence Errington John Scaife 《Molecular & general genetics : MGG》1975,143(1):79-83
Summary Studies on the rate of synthesis of the and subunits of RNA polymerase in haploid strains of Escherichia coli K12 containing poorly-suppressed rif
am
o
mutations provide conclusive evidence that synthesis of at least these two subunits is regulated. 相似文献
16.
Frank Wunderlich 《The Journal of membrane biology》1972,7(1):220-230
Summary A simple formula is derived to calculate the nucleocytoplasmic RNA-Efflux per nuclear Pore complex per min (REP-rate) which is generally applicable both for growing and stationary eukaryotic cells. In actively growing cells this REP-rate is mainly dependent on the cytoplasmic RNA-pool, the number of RNA-transporting pores, and the growth constant of RNA. These parameters are determined in logarithmicTetrahymena pyriformis GL. In this organism, 45 molecules both of the larger ribosomal RNA (25s rRNA) and of the smaller (17s rRNA) are transported per pore per min from nucleus to cytoplasm. Pulse-label experiments with3H-uridine indicate that the 25s rRNA is obviously transferred more slowly to the cytoplasm than the 17s rRNA. We postulate a gating hypothesis on the regulation of the nucleocytoplasmic RNA-efflux by nuclear pore complexes. This gating hypothesis suggests that nucleopores are controlling points of secondary importance in the sequence of gene expression, and do not directly control the cytoplasmic protein synthesis in eukaryotic cells. 相似文献
17.
18.
S. N. Moralev E. V. Rozengart 《Journal of Evolutionary Biochemistry and Physiology》2001,37(5):469-491
An analytical review is performed of the literature data on the hydrolysis rate, affinity of substrate to active center, and constants of the substrate inhibition (K
ss) at hydrolysis of the choline (acetyl-, propyonyl-, butyrylcholine, acetyl--methylcholine) and/or of corresponding thiocholine substrates by 59 cholinesterases from 49 different animals (chordate, insects, molluscs, nematodes). The characteristic peculiarities of enzymes from different groups of animals are revealed. The absence of regular changes of parameters of the cholinesterase substrate specificity in the course of evolutionary development is shown. 相似文献
19.
E. S. Kalyaeva I. S. Sever V. G. Nikiforov O. N. Danilevskaya 《Molecular & general genetics : MGG》1980,178(3):669-674
Summary As has been shown previously, RNA polymerase subunit ts-mutation rpoC1 results in an overproduction of RNA polymerase subunits at nonpermissive temperature. The mutant enzyme shows low activity in vitro and a sedimentation coefficient 9S which is characteristic of immature core polymerase. In this paper we describe a mutation designated opr1 which suppresses RNA polymerase subunit overproduction. The mutation was found among Ts+ revertants of the Ts double mutant carrying a rpoC1 mutation and a rif-r rpo B251 mutation. Opr1 is closely linked to the original rpo mutations and shows complete trans-dominance. Although opr1 seems to affect RNA polymerase, it does not suppress the accumulation of immature 9S RNA polymerase and does not restore the activity of the RpoC1 mutant enzyme. This and other results of a comparison of strains carrying different combinations of rpoC1, rpoB251 and opr1 mutations suggest that neither inhibition of total RNA and protein synthesis, nor the low RNA polymerase activity in vitro, nor the apparent defects in enzyme maturation, nor the enzyme degradation observed at 42°C are responsible for the overproduction in RpoC1 strains. 相似文献
20.
Summary The efficiency of ribosomal protein S20 to act as repressor of its own synthesis in an in vitro system was found to depend greatly on the procedures employed to purify this protein. Whilst conventionally purified r-protein S20 inhibited its own synthesis by some 30%, up to 90% inhibition was observed if milder purification conditions were used. Evidence is presented that the latter preparation shows also a higher binding affinity to 16S rRNA. 相似文献