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Precisely detecting oestrus is important for artificial insemination. The aims of this study were to identify oestrus‐specific sow mucus proteins to determine the optimal time for artificial insemination. The proestrous‐ and oestrous‐stage mucus proteins were purified and analysed with proteomic tools such as two‐dimensional gel electrophoresis and matrix‐assisted laser desorption/ionization–time‐of‐flight analyses. Among the differentially expressed proteins, the dimethylarginine dimethylaminohydrolase 2 (DDAH2) protein showed a 3.6‐fold increase during the proestrous stage compared to that during the oestrous stage. A western immunoblot study revealed that two of three sow mucus samples clearly showed negative anti‐DDAH2 antibody activity during the oestrous stage. This study demonstrated that the pig DDAH2 mucus protein exists during the proestrous stage, but not during the oestrous stage, suggesting that mucus DDAH2 could be useful as an oestrus detection marker.  相似文献   
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AIM: To examine the infective dose, incubation period and disease progression of an isolate of Salmonella enterica serotype Typhimurium definitive type 160 (DT160) originating from a naturally-infected house sparrow (Passer domesticus) during an outbreak of the disease in New Zealand.

METHODS: Thirty-six house sparrows captured from the wild and free of Salmonella spp were divided into six groups of six birds, housed individually, and inoculated orally with phosphate buffered saline (PBS) or 101, 102, 103, 105, 2 × 108 colony forming units (cfu) of the outbreak strain of S. Typhimurium DT160. The birds were observed for 10 days for clinical signs and/or mortality, and faecal samples were collected to determine excretion of S. Typhimurium. The birds were eutha- nised 11 days post-inoculation (p.i.) and a wide range of tissue samples were collected for histopathological examination, and culture and typing of Salmonella spp. Macro-restriction profiling by pulsed-field gel electrophoresis (PFGE) using XbaI was performed for the epidemiological typing of S. Typhimurium DT160 isolates.

RESULTS: Mortality in house sparrows inoculated with S. Typhimurium DT160 was dose-dependent, and 2/6 birds inoculated with 105 cfu and all six birds inoculated with 2 × 108 cfu died during the study. Infected sparrows displayed few clinical signs, apart from diarrhoea and/or polyuria, fluffed plumage, and sitting on the floor of the cage. Faecal excretion of DT160 occurred briefly in two birds inoculated with 102 cfu and four birds inoculated with 103 cfu, on most days in five birds inoculated with 105 cfu, and continuously in six birds inoculated with 2 × 108 cfu. DT160 was isolated from the livers of three birds which received 103 cfu, five birds dosed with 105 cfu, and all six birds given 2 × 108 cfu. Following necropsy, histopathological lesions similar to those seen in the natural disease were observed in the liver or spleen of three birds which received 103 cfu, and all birds dosed with ≥105 cfu.

CONCLUSION: The results indicate that an isolate of S. Typhimurium DT60 originating from house sparrows in New Zealand is pathogenic to these birds and that the response is dose- dependent. The persistence and excretion of the pathogen may last for at least 10 days. This confirms that sparrows infected with DT160 could be a source of infection to humans and other in-contact animals.  相似文献   
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The objective of this study was to determine the effects of gonadotropins on in vitro maturation (IVM) and electrical stimulation on the parthenogenesis of canine oocytes. In experiment I, cumulus oocyte complexes were collected from ovaries at a random phase of the oestrus cycle and cultured on maturation medium treated with hCG or eCG for 48 or 72 h. There were no significant differences in the effects on the metaphase II (MII) rate between the hCG and eCG treatment groups over 48 h (5.4% vs 5.5%). The MII rate in the co-treatment group of hCG and eCG for 48 h was higher than in each hormone treated group (15.5%, p < 0.05). In experiment 2, the parthenogenetic effect on oocyte development, at various electrical field strengths (1.0, 1.5, 2.0 kV/cm DC) for 60 or 80 μs with a single DC pulse after IVM on the co-treatment of hCG and eCG, was examined. The rate of pronuclear formation (37.1%) in electrical activation at 1.5 kV/60 μs without cytochalasin B (CB) was higher than that of oocytes activated in the other groups (p < 0.05). However, we did not observe the cleavage stages. Also, CB did not influence parthenogenesis of canine oocytes. The results showed that the pronucleus formation rate, indicative of the parthenogenesis start point, could be increased by electrical stimulation. Therefore, these results can provide important data for the parthenogenesis of canine oocytes and suggest the probability of parthenogenesis in canines.  相似文献   
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马铃薯晚疫病广谱抗性基因Rpi-blb1(克隆于Solanum bulbocastanum)及其两个同源抗病基因Rpi-sto1(克隆于Solanum stoloniferum)和Rpi-pta1(克隆于Solanum papita)的抗性可能已被高度进化的晚疫病菌株所克服。为证实此观点,将从荷兰田间和墨西哥野外S.bulbocastanum和S.stoloniferum病株上采集的晚疫病菌株重新接种于具有共同遗传背景(感病栽培品种Desiree)的Rpi-blb1及其同源基因转化体和3个野生种植株上,测试Rpi-blb1及其同源基因的抗性是否已被克服。结果表明,采自墨西哥野外S.stoloniferum的两个菌株Pic99189和Pic99192已经克服了Rpi-blb1及其同源基因的抗性;在野生种植株的测试中,只有S.papita的抗性明显地被菌株Pic99192所克服。同时发现在转基因植株离体叶片接种试验中,高抗晚疫病菌的转化体需要在多个转化体间进行选择。从采自中国4个不同地区晚疫病菌株接种sto1.Desiree转化体的小规模测试中可推断,Rpi-blb1及其同源抗性基因在中国仍具有潜在的应用价值。  相似文献   
57.
Microbial environment is one of the important factors that affect the quality of preserved semen. Iodine methionine (IM), participating in the production and activation of metabolic enzymes, is a new type of amino acid chelate. To date, there has been no report to evaluate the effects of IM on boar semen preservation at 17°C. This study was designed to investigate the effects of IM on boar sperm quality and reproductive performance during liquid storage at 17°C and its antibacterial effect. Semen samples collected from six Yorkshire boars were diluted with basic liquid containing different concentrations of IM (0, 20, 40, 80, 160 and 320 μM). Subsequently, sperm motility, plasma membrane integrity and acrosome integrity were determined. After 6 days of preservation, the difference in microbial composition between control group and 80 μM IM group was compared using 16S rDNA sequencing, and the effects of IM on reproductive performance were also compared and analysed between the two groups. The results demonstrated that 20, 40 and 80 μM IM improved boar sperm motility, plasma membrane integrity and acrosome integrity. 80 μM IM was the optimum concentration. Conversely, 160 and 320 μM IM resulted in deleterious consequences to boar sperm quality compared to the control group and other treatment groups (< .05). After 6 days of preservation, sperm motility, plasma membrane integrity and acrosome integrity were 56.0%, 51.8% and 59.4%, respectively. There was no significant difference in non‐return rate between the two groups (> .05). But the litter size of 80 μM IM group was significantly higher than that of control group (< .05). 80 μM IM inhibited proliferation of the phylum Proteobacteria and the genus Staphylococcus as well as Pseudomonas (< .05). Further studies are required to understand the antibacterial mechanism of IM in liquid‐preserved boar semen.  相似文献   
58.
The pregnancy rates obtained after the transfer of cryopreserved in vitro‐produced (IVP) embryos are usually low and/or inconsistent. The objective of this study was to evaluate the pregnancy rates of Holstein, Gyr and Holstein × Gyr cattle after the transfer of vitrified IVP embryos produced with X‐sorted sperm. Seventy‐two Gyr and 703 Holstein females were subjected to ovum pickup (OPU) sessions, followed by in vitro embryo production using semen from sires of the same breeds. Embryos (1636 Holstein, 241 Gyr and 1515 Holstein × Gyr) were exposed to forskolin for 48 h prior to vitrification. The pregnancy rate achieved with Gyr dam and sire was 46.1%, which was similar (p = 0.11) to that of Holstein dam and Gyr sire (40.3%). Crossing Gyr dams with Holstein sires resulted in a pregnancy rate of 38.9% and did not differ (p = 0.58) from the pregnancy rate obtained with the cross between Holstein dams and Gyr sires. The rate obtained with Holstein dam and sire was 32.5%. The average pregnancy rate was 36.6%, and no difference was found in the proportion of female foetuses (88.8%, in average) among breeds (p > 0.05). In conclusion, transfer of cryopreserved X‐sorted embryos represents an interesting choice for dairy cattle. Despite the small differences between pregnancy rates, we highlight the efficiency of this strategy for all of the racial groups studied.  相似文献   
59.
In model terrestrial ecosystems maintained for three plant generations at elevated concentrations of atmospheric carbon dioxide, increases in photosynthetically fixed carbon were allocated below ground, raising concentrations of dissolved organic carbon in soil. These effects were then transmitted up the decomposer food chain. Soil microbial biomass was unaffected, but the composition of soil fungal species changed, with increases in rates of cellulose decomposition. There were also changes in the abundance and species composition of Collembola, fungal-feeding arthropods. These results have implications for long-term feedback processes in soil ecosystems that are subject to rising global atmospheric carbon dioxide concentrations.  相似文献   
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