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PD Dr. G. F. Jirikowski J. F. Ramalho-Ortigao K. W. Kesse F. E. Bloom 《Histochemistry and cell biology》1990,94(2):187-190
Summary We recently described a nonradioactive method for in situ hybridization with 5-bromo-2-deoxyuridine (BrdU) labelled oligonucleotide
probes. An antibody to BrdU and immunocytochemistry were used in order to detect the hybridization signal. We have now applied
this method to semithin Epon sections, in order to hybridize consecutive sections through single cells with different probes
and to stain them with antibodies to neuropeptides. It could be shown that Epon embedding preserves mRNA well. In the present
study we used a BrdU labelled synthetic oligonucleotide probe complementary to a fragment of the vasopressin precursor and
an antibody to Arg-vasopressin. Vasopressin mRNA was demonstrable in a fraction of the vasopressin immunoreactive neurons
in the magnocellular nuclei. In addition some of the magnocellular neurons showed either hybridization or vasopressin immunostaining
only, perhaps indicating different stages of synthetic and secretory activity.
The method described seems to be a valuable tool for studying synthetic activity in peptidergic neurons on a single cell level.
The method might also have potential for in situ hybridization on the electronmicroscopical level. 相似文献
4.
Influence of Seismic Stress on Photosynthetic Productivity, Gas Exchange, and Leaf Diffusive Resistance of Glycine max (L.) Merrill cv Wells II
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Relative growth rate (RGR), leaf water potential (Ψw), transpiration rate (Tr), photosynthetic rate (Pn), and stomatal and mesophyll resistances to CO2 exchange were measured or calculated to determine how periodic seismic (shaking) stress decreased dry weight accumulation by soybean (Glycine max [L.] Merrill cv Wells II). Seismic stress was applied with a gyratory shaker at 240 to 280 revolutions per minute for 5 minutes three times daily at 0930, 1430, and 1930 hours. Fifteen days of treatment decreased stem length 21%, leaf area 17%, and plant dry weight 18% relative to undisturbed plants. Seismic stress also decreased RGR 4%, which was due entirely to decreased net assimilation rate. Transpiration decreased 17% and leaf Ψw increased 39% 30 minutes after treatment. A reduction in Pn began within seconds after the onset of treatment and had declined 16% after 20 minutes, at which time gradual recovery began. Assimilation rate recovered fully before the next seismic treatment 5 hours later. Resistance analysis and calculation of leaf internal CO2 levels indicated that the transitory decrease in Pn caused by periodic seismic stress was due to increased stomatal resistance on the abaxial leaf surface. 相似文献
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Five species of helminths were monitored in a population of snowshoe hares (Lepus americanus) near Rochester, Alberta, during 1961-1977. Prevalence of both Obeliscoides cuniculi and Protostrongylus boughtoni among young hares averaged about 50% by age 2 mo, then tended to level off. Prevalence of Taenia pisiformis (cysticerci) and Dirofilaria scapiceps rose more slowly, but continued to increase steadily beyond their mean levels of 8% and 1% at age 2 mo. There were well defined seasonal (within-year) cycles in prevalence of O. cuniculi and P. boughtoni that were generated evidently to a major degree by arrested development of larvae in fall and renewed development in late winter. It was hypothesized that renewed larval development was triggered (in February) in O. cuniculi by the seasonal rise of circulating pituitary gonadotrophins, and (in April) in P. boughtoni by the seasonal rise of gonadal androgens and estrogens. Indices to gonadal hormone levels in hares indicated that these increased most rapidly among males, and may have accounted for the higher prevalences of P. boughtoni in males during April-May. Neither T. pisiformis nor D. scapiceps exhibited conspicuous seasonal changes in prevalence. Maximum prevalence of T. pisiformis was attained at about 1 yr of age, whereas D. scapiceps increased among adult snowshoes through age 2 yr before stabilizing. Long-term (between-year) changes in prevalence of O. cuniculi, T. pisiformis, and D. scapiceps were correlated significantly with the cyclic hare population which declined from a peak in fall 1961 to a low in 1965-1966, rose to another peak by fall 1970, and declined again to a low in 1975. There was no detectable time lage between this "10-yr" cycle in hare density and the cycles of parasite prevalence among juveniles (less than 1 yr of age). Among adult hares, the cycle of O. cuniculi prevalence was likewise synchronous with that of the hare population, but the cycles of D. scapiceps and T. pisiformis lagged by approximately 1 and 2 yr, respectively. This lag in T. pisiformis prevalence was largely inexplicable to us. Our data on P. boughtoni were not suitable for analyses of between-year trends; nor were those for the fifth helminth, Taenia serialis (coenuri), because mean prevalence was less than 1% among both juveniles and adults. An apparent decline in T. serialis after the early 1950's, and its continued scarcity thereafter, paralleled a major change in numbers of one important definitive host--the red fox (Vulpes vulpes).(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
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Transposon mutagenesis of baculoviruses: analysis of TFP3 lepidopteran transposon insertions at the FP locus of nuclear polyhedrosis viruses 总被引:3,自引:0,他引:3
We report the complete sequences of two representatives of the TFP3 transposable element family of the lepidopteran, Trichoplusia ni. These elements were isolated as insertions mobilized from the Lepidopteran host genome into two closely related nuclear polyhedrosis viruses (NPV) during infection. Both elements inserted within the 500-bp FP locus of the respective viral genomes (map units 36.0 to 37.0), causing a distinctive plaque morphology phenotype and the loss of a 25-kDa viral-specific protein. Both insertions occurred at the identical TTAA target site in the respective genomes, in the same relative orientation, and are flanked by 15-bp imperfect inverted repeats. The inserted elements interrupt the 25K open reading frame (ORF). One of these FP mutants undergoes spontaneous reversion. Sequence analysis at the excision site of a spontaneous revertant demonstrates that the TFP3 elements are capable of precise excision, restoring the expression of the 25-kDa protein. We also compare the sequences of the 25K genes of the Autographa californica and Galleria mellonella viruses (AcMNPV and GmMNPV, respectively). The 25K gene sequences diverge in five areas, resulting in an additional EcoRV and TaqI site within the GmMNPV 25K gene, and extension of the ORF for an additional 2 amino acids at the C-terminus of the predicted GmMNPV 25 kDa protein. The phenomenon of transposon mutagenesis of Baculovirus genomes provides a unique opportunity for analysis of transposon mobility. 相似文献
8.
J W Cary D J Petersen E T Papoutsakis G N Bennett 《Applied and environmental microbiology》1990,56(6):1576-1583
Coenzyme A (CoA)-transferase (acetoacetyl-CoA:acetate/butyrate:CoA-transferase [butyrate-acetoacetate CoA-transferase] [EC 2.8.3.9]) of Clostridium acetobutylicum ATCC 824 is an important enzyme in the metabolic shift between the acid-producing and solvent-forming states of this organism. The purification and properties of the enzyme have recently been described (D. P. Weisenborn, F. B. Rudolph, and E. T. Papoutsakis, Appl. Environ. Microbiol. 55:323-329, 1989). The genes encoding the two subunits of this enzyme have been cloned by using synthetic oligodeoxynucleotide probes designed from amino-terminal sequencing data from each subunit of the CoA-transferase. A bacteriophage lambda EMBL3 library of C. acetobutylicum DNA was prepared and screened by using these probes. Subsequent subcloning experiments established the position of the structural genes for CoA-transferase. Complementation of Escherichia coli ato mutants with the recombinant plasmid pCoAT4 (pUC19 carrying a 1.8-kilobase insert of C. acetobutylicum DNA encoding CoA-transferase activity) enabled the transformants to grow on butyrate as a sole carbon source. Despite the ability of CoA-transferase to complement the ato defect in E. coli mutants, Southern blot and Western blot (immunoblot) analyses showed that neither the C. acetobutylicum genes encoding CoA-transferase nor the enzyme itself shared any apparent homology with its E. coli counterpart. Polypeptides of Mr of the purified CoA-transferase subunits were observed by Western blot and maxicell analysis of whole-cell extracts of E. coli harboring pCoAT4. The proximity and orientation of the genes suggest that the genes encoding the two subunits of CoA-transferase may form an operon similar to that found in E. coli.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
Summary The microproblematicumPycnoporidium ? eomesozoicum
Flügel, 1972, from Upper Triassic reefs of the Alpine-Mediterranean region, Turkey Oman and Iran (originally interpreted as possible
alga) represents the type species of a new strophomenid brachiopod genus (Gosaukammerella n.g.). The genus is characterized by a very small, millimeter-sized plano-convex shell, whose ventral valve is attached to
the substratum (mainly sponges) by symmetrically arranged outgrowths developing from a pseudopunctate, lamellose foliated
shell wall and composed of densely spaced subparallel ‘tubes’ comparable with productide spines secreted by papillose extensions
of the mantle.Gosaukammerella seems to be the only reliable candidate for the existence of post-Paleozoic strophomenid (productid ?) brachiopods.
Gosaukammerella eomesozoica is restricted to possibly cryptic, shaded reef environments inhabited predominantly by sponges serving as substrates for
micromorphic brachiopods. 相似文献
10.
Perng-Kuang Chang Jeffrey W. Cary Jiujiang Yu Deepak Bhatnagar Thomas E. Cleveland 《Molecular genetics and genomics : MGG》1995,248(3):270-277
Aflatoxins comprise a group of polyketide-derived carcinogenic mycotoxins produced byAspergillus parasiticus andAspergillus flavus. By transformation with a disruption construct, pXX, we disrupted the aflatoxin pathway inA. parasiticus SRRC 2043, resulting in the inability of this strain to produce aflatoxin intermediates as well as a major yellow pigment in the transformants. The disruption was attributed to a single-crossover, homologous integration event between pXX and the recipientA. parasiticus genome at a specific locus, designatedpksA. Sequence analysis suggest thatpksA is a homolog of theAspergillus nidulans wA gene, a polyketide synthase gene involved in conidial wall pigment biosynthesis. The conservedβ-ketoacyl synthase, acyltransferase and acyl carrier-protein domains were present in the deduced amino acid sequence of thepksA product. Noβ-ketoacyl reductase and enoyl reductase domains were found, suggesting thatpksA does not encode catalytic activities for processingβ-carbon similar to those required for long chain fatty acid synthesis. ThepksA gene is located in the aflatoxin pathway gene cluster and is linked to thenor-1 gene, an aflatoxin pathway gene required for converting norsolorinic acid to averantin. These two genes are divergently transcribed from a 1.5 kb intergenic region. We propose thatpksA is a polyketide synthase gene required for the early steps of aflatoxin biosynthesis. 相似文献