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61.
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In cultured rat anterior pituitary cells, the agonist [Asu1,6, Arg8]vasopressin (AVP-A) increased by 1.5-fold 32Pi incorporation into phosphatidic acid (PA), as early as 15 s after its addition. Increased phosphatidylinositol (PI) labeling became significant 4 min after AVP-A addition. Dose-response measurements with AVP-A showed ED50 values of 76 and 62 nM for PA and PI labeling, respectively. Peptide corticotropin-releasing factor (CRF) (0.1 microM) did not affect the stimulatory effect of AVP-A on PA and PI labeling. These data suggest that stimulation of PI metabolism in corticotrophs may be one of the early events involved in the stimulation of ACTH release induced by vasopressin.  相似文献   
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Monoploid potato (2n=1×=12) can be derived either paternally through anther or microspore culture (androgenesis) or maternally through crossing with a haploid-inducing pollinator (gynogenesis). Androgenic and gynogenic monoploid populations, derived from each of two Solanum phureja clones, were compared in both greenhouse and field studies, and their frequency of cells at the 1x, 2x and 4x DNA contents was estimated by flow cytometry of in vitro plantlets. In 15 of 17 comparisons of morphological data (plant height, number of main stems, vigor, leaf length and width, internode length, tuber number and tuber weight) where a significant difference was found due to derivation, the androgenic monoploids were agronomically superior to their gynogenic counterparts (13–18% greater leaf size, double to triple the total tuber yield). Only plant height was significantly greater (26–27%) in the gynogenic monoploids. Flow cytometry revealed that the gynogenic monoploids retained 5% more cells at the monoploid level, whereas androgenic monoploids exhibited 27% more endopolyploid cells at the tetraploid level. Received: 19 April 2000 / Accepted: 17 November 2000  相似文献   
65.
Objective: The fat mass and obesity associated (FTO) gene is related to obesity, but the regulation of FTO expression in adipose tissue is not fully understood. We investigated FTO expression in paired subcutaneous and omental adipose tissues (SAT and OAT) from healthy women undergoing gynecological surgeries, and its relation with adiposity and insulin sensitivity. Design and Methods: FTO expression in SAT of type 2 diabetic patients treated or not with Rosiglitazone was also compared. Results: Both the mRNA and protein levels of FTO were higher in OAT from women than in SAT. Only OAT FTO protein levels negatively correlated with BMI and body fat mass, whereas SAT FTO mRNA levels were negatively correlated with subcutaneous fat deposition. In addition, SAT FTO mRNA and protein levels were increased in insulin resistant women (high HOMA) compared to insulin sensitive women (low HOMA), whereas OAT FTO expression was not different between these two subgroups. Interestingly, FTO mRNA levels were increased in SAT of type 2 diabetic patients, and treatment of diabetics with Rosiglitazone improved insulin sensitivity and reduced SAT FTO mRNA levels. Lastly, FTO expression was transiently increased in the early phase of 3T3‐L1 cell differentiation, which coincides with the induction of PPARγ2 expression. However, partial reduction of FTO did not impact PPARγ2 expression and adipocyte differentiation. Conclusion: Therefore, FTO gene expression is higher in OAT than in SAT in lean to moderately obese women. OAT FTO expression is associated with adiposity, whereas SAT FTO expression is associated with insulin sensitivity. These associations are independent of an effect of FTO on adipocyte differentiation.  相似文献   
66.
Segregation patterns of polymorphic simple sequence repeat (SSR) primer pairs were investigated in monoploid potato families derived from anther culture. A total of 14 primers developed from the sequences in the database, as well as from a genomic library of potato, was used. Distorted segregation was observed for seven (50%) polymorphic loci among monoploids derived from an interspecific hybrid. Similar distortion was observed for only one of five loci that could be contrasted between the two monoploid families. Segregation distortion was less common in the sexually derived backcross population between the interspecific hybrid and either of its parents. One locus could be putatively linked to a lethal allele because it showed distorted segregation in both monoploid families, a group of 70 heterozygous diploids derived from unreduced gametes through anther culture, and a backcross population. These diploids were used to map the polymorphic SSR markers with respect to the centromeres using half-tetrad analysis. The majority of the SSR loci mapped more than 33 cM from the centromere, suggesting the occurrence of a single crossover per chromosome arm.  相似文献   
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In the highly competitive market of commercial bakers' yeast, fermentations are operated for maximum efficiency and minimum production cost. In order to maintain competitiveness, the fermentations must be highly consistent with minimum variation in yeast performance, maximum yield on raw materials, and minimum production of undesirable side products. The use of advanced instrumentation is of critical importance to achieving these goals by the production engineer. An in situ optical density probe was used to determine the yeast cell density in full-scale commercial bakers' yeast fermentations. The optical density probe results were compared with oxygen uptake rate analyses, packed cell volume, and off-line measured cell dry weights. The most accurate measurement of cell density was found to be the optical density probe. This instrument allowed the on-line determination of cell density with highly consistent results from fermentation batch to batch and with out the need for intermittent recalibration. (c) 1995 John Wiley & Sons, Inc.  相似文献   
69.
Summary The basic fluorochrome dye acridine orange was applied to different tissues of the rat for staining mast cells. This was performed under different fixation conditions in order to assess the effects of fixative fluids on the resulting fluorescent staining. Under the conditions described, acridine orange has constantly revealed mast cells in bright fluorescence in tissues where they are known to be present normally. The results are discussed in reference to each fixative used. But the method failed to show the mucosal mast cells in the stomach and duodenum. This is proposed as a new element for the further characterization of these cells.This work was supported by the Medical Research Council of Canada (Grant No. 2,236).The author is indebted to Mrs. H. Gonzalez for her skillful technical assistance.  相似文献   
70.
The activity and longevity of Soybean mosaic virus (SMV) in soybean callus culture were investigated with 11 SMV strains which are distinguished by differential reactions on soybean cultivars [Glycine max (L.) Merr.]. Dual cultures (soybean callus and SMV) were initiated by direct culture of SMV-infected leaves from susceptible soybean plants on Msoy and MS agar medium. Established SMV-callus cultures were maintained at 25 °C under light, subcultured to fresh MS medium at 2-month intervals or as necessary, and assayed periodically for virus infectivity. The infected calluses on MS medium grew better and stayed active longer than those on Msoy medium. At 10–15 °C, calluses and SMV were viable and active for 13–15 weeks or longer without subculture. The infectivity of SMV from callus cultures was comparable with that of SMV from infected plants, and remained stable for more than a year through five successive subcultures. Callus tissues of dual cultures were uniformly infected by SMV, thus ensuring infectious subcultures by random transfers. Production of in vitro inoculum can be significantly increased by multiple subcultures. Biological integrity of the SMV cultures was maintained with no change of viral virulence and pathotype. The method is of value for preserving a collection of SMV strains in a highly infectious and readily available form and reduces the chance of contamination or loss in viability.  相似文献   
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