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1.
SUMMARY: Behavioral experiments concerning a releaser pheromone in the urine of female rainbow trout were performed using immature fish administered orally with 17α-methyltestosterone (MT) during the non-spawning season. The urine was collected by catheter. The frequency of entries of test fish was recorded in each channel scented by test and control solutions in a Y-maze trough. The behavior of both MT-treated and control fish demonstrated that they could not discriminate the differences between distilled and environmental water as control solutions. There was also no difference between MT-treated and control fish when distilled and environmental water were introduced. The MT-treated immature fish were attracted to the channel scented by ovulated female urine. Neither coelomic fluid nor the immature female urine had any effect on the behavioral responses of MT-treated fish, while immature control fish had no preference for the urine of ovulated females. These results suggest in rainbow trout that ovulated female urine contains a releaser pheromone to attract mature males, and that androgens are involved in the sensory mechanisms detecting the releaser pheromone in fish.  相似文献   
2.
The seasonal change in petal color and pigmentation of 29 commercial Eustoma cultivars was studied. The flowers are basically divided into four groups according to the major anthocyanidin phenotype in association with petal coloration, i.e., delphinidin (Dp)-based (purple flower), cyanidin (Cy)-based (reddish purple flower), pelargonidin (Pg)-based (pink flower), and none (white flower) groups. The constitution of petal anthocyanidins was not changed by forcing treatment in most of the flowers. Lightness (L*) and chroma (C*, color saturation) showed a change along with the increase/decrease of hue angle difference (ΔH*), thus simultaneously the chromatic tonalities tended to move to redder and bluer, respectively. Floral pigment clustering described two flower groups in a dendrogram, based on anthocyanidin constitutions as phenetic markers, which are apparently the Dp- and Pg-based phenotypes of anthocyanidin syntheses. The Cy-based flowers made a subcluster with the Pg-based flowers, indicating a close relationship in the biosynthesis of the two anthocyanidins, and suggesting the Dp- and Pg-syntheses complement one another.  相似文献   
3.
Mycoplasma pneumonia of swine (MPS) lung lesions and immunogenic properties were compared between a Landrace line that was genetically selected for reduced incidence of pulmonary MPS lesions, and a non‐selected Landrace line. The MPS‐selected Landrace line showed significantly lower degrees of pulmonary MPS lesions compared with the non‐selected Landrace line. When changes in immunity before and after vaccination were compared, the percentage of B cells in the peripheral blood of the MPS‐selected Landrace line was significantly lower than that of the non‐selected line. Furthermore, the concentration of growth hormone and the mitogen activity of peripheral blood mononuclear cells in the MPS‐selected Landrace line showed significantly (P < 0.05) lower increases after vaccination than the non‐selected line. Conversely, the concentration of peripheral blood interferon (IFN)‐γ and salivary immunoglobulin A (IgA) after Mycoplasma hyopneumoniae vaccination was significantly higher in the MPS‐selected Landrace line than in the non‐selected line. Gene expression of toll‐like receptor (TLR)2 and TLR4 was significantly higher in the MPS‐selected Landrace line in immune tissues, with the exception of the hilar lymph nodes. The present results suggest that peripheral blood IFN‐γ, salivary IgA TLR2, and TLR4 are important immunological factors influencing the development of MPS lesions.  相似文献   
4.
Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions were compared between the immunity‐selected Large White line and the non‐selected Large White line. The selected Large White line showed a higher level of pulmonary MPS lesions compared with the non‐selected Large White line. Subsequent to vaccination, the percentage of natural killer cells and T cells (CD3+CD4+CD8 and CD3+CD4?CD8+ T cells) were significantly increased in the non‐selected line but remained unchanged in the immunity‐selected Large White line. Secretion of Mycoplasma hyopneumoniae vaccine‐specific immunoblogulin G and phagocyte activity in peripheral blood were significantly higher in the immunity‐selected Large White line than in the non‐selected line. Expression of interleukin (IL)‐4 and IL‐6 messenger RNA in hilar lymph nodes was significantly lower in the immunity‐selected Large White line than in the non‐selected line. However, expression of IL‐10 in all immune tissues was significantly higher in the immunity‐selected Large White line. These results suggest that the selection for high immunity was not effective in increasing resistance to MPS lung lesions.  相似文献   
5.
To understand the influence of crossbreeding on Mycoplasma pneumonia of swine (MPS) resistance and immune characteristics, two crossbred lines were characterized. One crossbred line, LaWa, was generated by crossing the MPS pulmonary lesion selected Landrace line (La) and the highly immune‐selected Large White line (Wa). The second crossbred line, LaWb, was generated by crossing the La line and the nonselected Large White line (Wb). The crossbred LbWb line (nonselected Landrace line × nonselected Large White line) and the La line were used as controls. The LaWa and LaWb lines had an intermediate level of MPS lung lesions between La and LbWb lines, although the difference was not statistically significant. After stimulation with sheep red blood cells (SRBCs), the LaWb and LaWa lines showed immune characteristics similar to that of the La line; the number of monocytes in peripheral blood increased, while B cells, T cells, secretion of SRBC‐specific immunoglobulin G, and interleukin (IL)‐13 decreased. Additionally, the number of natural killer (NK) cells and the expression of IL‐4 and IL‐17 were significantly higher in the LaWb and LaWa lines, respectively. These data suggested that crossbreeding of La and Wa lines resulted in the inheritance of some of the selected immune responses.  相似文献   
6.
The incidence of canine rabies has been widely reported in Brazil, and new rabies virus (RV) variants, genetically similar to canine RV, have recently been isolated from foxes. In order to derive the epidemiological characteristics of Brazilian Carnivora RV, Brazilian RVs isolated from dogs, cats, and foxes were genetically analyzed. Brazilian Carnivora RV isolates were divided into 2 main lineages. The predominant lineage was found in dogs and cats, which included the Argentinean and Bolivian Carnivora RV isolates, and was extensively distributed throughout Brazil and surrounding countries. The other lineage consisted of three sublineages containing Brazilian dog and fox RV isolates, with the dog sublineages located on an internal branch of 2 fox sublineages, suggesting that RV transmission events might have occurred between foxes and dogs in the past. These results suggest that contact between dogs and wildlife has the potential to generate new rabies variants and that it is important to control RV infection cycles in both dogs and wildlife to prevent spread of rabies infection.  相似文献   
7.
ManyDrechslera species that haveCochliobolus sp. as a perfect stage produce a related group of ophiobolins, sesterterpenoids (C-25’s), which are phytotoxic to a wide range of plants. One of the most toxic ophiobolins is 6-epiophiobolin A and it is produced by all of theDrechslera species thus far studied. On the other hand, some novel ophiobolins have been found inD. oryzae: ophiobolin J, 6-epiophiobolin I, and 8-deoxyophiobolin J. Potentially, genetic crosses made between these fungi could yield novel organisms, producing novel combinations of the ophiobolins, and thus new pathotypes. Ophiobolins are being used in tissue culture systems to screen plants for sensitivity to these toxins. Paper presented at the Bat-Sheva Seminar on Host - Fungus Interaction, Jerusalem, Israel (March 14–25,1988).  相似文献   
8.
Restriction enzyme-mediated integration (REMI) mutagenesis was used to isolate mutants of Fusarium oxysporum f. sp. melonis impaired in pathogenicity. The race 2 strain Mel02010 was transformed with linearized pSH75, conferring resistance to hygromycin B, with or without the enzyme used to linearize the plasmid. Addition of restriction enzymes did not affect the transformation frequency. A total of 2929 REMI transformants were tested for pathogenicity to three melon cultivars, Amus, Ogon 9 and Ohi. The race 2 strains are pathogenic to Amus and Ogon 9, but not to Ohi. Of 43 transformants with reduced pathogenicity on susceptible melon cultivars, 12 mutants were examined in detail for pathogenicity, vegetative growth and integrative mode of pSH75. The levels of pathogenicity varied among these mutants. Two mutants (B48 and B137) almost completely lost pathogenicity to both susceptible cultivars, and the others had reduced pathogenicity. Mutants B48, B241, B886 and X36 were also impaired in vegetative growth. Mutant B809 was a biotin auxotroph. By DNA gel blot analysis, nine mutants were found to contain a single copy of the transformation vector. These mutants may thus be useful in isolating genes involved in pathogenicity. Received 22 December 2000/ Accepted in revised form 16 April 2001  相似文献   
9.
Effects of deltamethrin, a powerful pyrethroid insecticide, on the protein phosphorylation and dephosphorylation processes during depolarization in rat brain synaptosomes were studied by using [32P]phosphoric acid as a starting radiotracer and high external concentration of potassium ions or veratridine (10?-5 M) as depolarizing agents. At the onset of depolarization there was a quick rise in phosphorylation in various synaptic proteins for about 15–30 s followed by a gradual decline in levels of phosphorylation. The effect of deltamethrin (10?-7 M) on this system was found to be dependent on the length of preincubation of the synaptosome with the pesticide prior to depolarization. At an early stage (0–3 min preincubation period) it caused a modest suppression of protein phosphorylation activities. When the period of deltamethrin preincubation was extended to 5–20 min, however, it caused a significant increase in protein phosphorylation throughout the depolarization period. At the later stage of the action of deltamethrin (e.g. preincubation period of 30–40 min), deltamethrin-treated synaptosomes no longer responded to the depolarization signal to raise the level of phosphorylation on many proteins. These results indicate that deltamethrin's actions on the synaptic process are complex. Depending on the length of exposure, its effects on protein phosphorylation responses in intact synaptosomes could be either stimulatory or inhibitory. To study the cause of deltamethrin-induced synaptic block at the later stage, effects of deltamethrin on protein kinases were studied by using lysed synaptic membranes with [gamma-32P]ATP. Deltamethrin was shown to inhibit calcium–calmodulin-dependent protein phosphorylation activities at 10?-7 M when given directly to the enzyme source 10 min prior to the addition of [32P]ATP. Such an observation helps to explain the inhibitory action of deltamethrin on protein phosphorylation which occurs at the late stage of its action (i.e. preincubation time > 20 min).  相似文献   
10.
Growth hormone secretion was evaluated in cattle. Clinically healthy bovine growth hormone (bGH) concentrations were 10.7 +/- 1.6 ng/ml in Holstein and 7.8 +/- 3.9 ng/ml in Japanese black cattle. The bGH concentration alternated at three-hour intervals, and tended to be higher at midnight and lower in the morning and before feeding. Insulin tolerance test (ITT) at an insulin dosage of 0.25 U/kg showed a significant increase of bGH concentration to 331 +/- 153% at 60 to 90 min after injection. In ITT applied to five under-growth calves of Japanese black cattle, the basal bGH concentrations were lower and peak values after insulin injection were shown to be significantly low. The ITT is useful for the clinical examination of bGH secretion in cattle.  相似文献   
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