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The objective of this study was to examine the effect of donor breed on pronuclear‐stage embryo yield to be used for DNA microinjection in a transgenesis goat program. Twelve Canindé and twelve Saanen goats were heat synchronized using a progestagen‐cloprostenol treatment. Forty‐eight hours before the sponge removal, superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH‐FSH‐P1, given twice daily in decreasing doses over 3 days. In addition, goats received 100 μg of GnRH and they were hand‐mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after sponge removal. Embryos were microinjected with a DNA construct and noticeable swelling of the nuclei was the criterion for successful microinjection. The total diameter, cytoplasm diameter, zona pellucida thickness and pronuclei diameter were measured for each microinjected embryo. A higher (p < 0.05) percentage of fertilized ova was observed in Canindé (89.9%) than Saanen (36.2%) goats. In addition, Canindé donors produced a higher percentage of pronuclear embryos when compared with Saanen: 72.5% vs 20.6% (p < 0.05), respectively. Successful microinjection was verified in 96.7% and 73.3% of times in Canindé and Saanen embryos, respectively (p < 0.05). Significant differences were observed for all morphometric parameters except for cytoplasm diameter. In conclusion, under our study experimental conditions, Canindé were more efficient than Saanen goats concerning the pronuclear embryo yield and manipulation. The use of Canindé goats in transgenesis programs could be increase the interest in their breeding and could be contribute to saving them from extinction.  相似文献   
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This study examined germination and dormancy in Galeopsis speciosa (Lamiaceae), a common summer annual weed in cold‐temperate areas. Seeds collected in southern Sweden were subjected to several experiments. The seeds were dormant at maturity. Seeds sown outdoors after collection produced a small number of seedlings that emerged early in the spring. After long cold stratification or stratification outdoors over two winters, the maximum germination was 40–50%; germination occurring over a wide range of temperatures. Warm stratification preceding cold stratification had no effect on germination, but repeated warm and cold periods seemed to promote germination. Gibberellic acid (GA) stimulated germination, but full germination was only achieved after more than 2 months of incubation at the most suitable temperature regime tested. Excised embryos grew and developed into normal seedlings. With these results, the species does not fit into the currently used system for seed dormancy classifications. The response to GA and the growth of excised embryos indicate non‐deep or intermediate physiological dormancy, but dormancy alleviation by stratification was not in line with the guiding principles for these classifications. Galeopsis speciosa has a strong dormancy that is sufficiently alleviated during the winter to allow germination of only part of a seed batch each year; hence a stepwise germination pattern occurs over a period of several years.  相似文献   
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Effects of a 20-h fermentation on cell wall polysaccharides from the mucilage of pulped coffee beans were examined and compared to those of unfermented beans, on alcohol insoluble residues (AIRs), their hot-water-soluble crude pectic substances (PECTs), and their hot-water-insoluble residues (RESs). Yields and compositions were very similar: AIRs, which consisted of approximately 30% highly methylated pectic substances, approximately 9% cellulose, and approximately 15% neutral noncellulosic polysaccharides, exhibited no apparent degradation. However, PECTs from fermented beans were shown to have undergone a slight reduction of their intrinsic viscosity and weight-average molecular weight by capillary viscosimetry and high-performance size-exclusion chromatography. After fermentation, hot-water-insoluble pectic substances of RES exhibited partial de-esterification. Removal of coffee bean mucilage by natural fermentation seems to result from a restricted pectolysis, the mechanism of which remains to be elucidated.  相似文献   
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Objectives To assess a method for monitoring depth of anaesthesia using components of middle latency auditory evoked potential (AEP) waveforms during anaesthesia with fentanyl/fluanisone and midazolam. Study design Prospective observational study. Animals Five female Wistar rats weighing between 210 and 250 g. Methods Implanted electrodes were used to record AEPs in animals receiving five doses of anaesthetic. Recordings were made at 5 minutes post‐injection (deep anaesthesia; no pedal withdrawal response, PWR) and then at 25 minutes (light anaesthesia; strong PWR). Responses showed five characteristic peaks occurring at 11, 14, 23, 42 and 68 ms that were measured for latency of occurrence and peak amplitude. Results Auditory evoked potential peaks P14, N23 and P42 were increased significantly in latency with successive anaesthetic injections [avg. F(1,4) = 12.53, p < 0.001; avg. F(1,4) = 10.6, p < 0.001; avg. F(1,4) = 3.9, p = 0.02, respectively]. Peak N23 showed a significant reduction in latency during the 20 minute recovery period following both the first and second anaesthetic injections (t(3) = 7.52, p = 0.005; t(4) = 5.17, p = 0.007, respectively). Peak P42 occurred significantly earlier 20 minutes following the second anaesthetic injection (t(4) = 4.75, p = 0.009). The mean overall depth of anaesthesia assessed using PWR scores was significantly correlated with the mean latency of peak N23, such that as the strength of PWR increased, N23 occurred significantly earlier (r = ?0.99, p = 0.01). The amplitude difference between peaks N23 and P42 increased after the second and third drug administrations [avg. F(1,4) = 10.65, p = 0.031 and avg. F(1,4) = 11.24, p = 0.028, respectively]. Conclusion The characteristics of these peaks, and in particular latency of peak N23, may provide a useful tool for assessing depth of anaesthesia produced by this, and possibly other anaesthetic agents.  相似文献   
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