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31.
Optimized somatic embryogenesis in Pinus strobus L. 总被引:5,自引:0,他引:5
Krystyna Klimaszewska Yill-Sung Park Cathy Overton Ian Maceacheron Jan M. Bonga 《In vitro cellular & developmental biology. Plant》2001,37(3):392-399
Summary Somatic embryogenesis (SE) initiation in Pinus strobus was optimized by the manipulation of plant growth regulator (PGR) concentrations in the culture medium. Modified Litvay medium
(MLV) of Litvay et al. (1985) supplemented with lower than routinely used PGR concentration increased initiation of established
embryogenic cultures from approximately 20 to 53%. The original developmental stage of zygotic embryos had a pronounced effect
on the SE response. The optimum stage was the pre- to shortly post-cleavage stage. A substantial genetic influence on initiation
of SE was indicated by a significant variance component due to families. Genotype X collection date and genotype X media interactions
had large effects on initiation of SE. The PGR levels in the culture medium prior to maturation had a significant effect on
subsequent production of mature somatic embryos. Embryogenic tissue initiated and proliferated on medium with a low level
of PGR consistently produced a high number of somatic embryos, indicating that optimized initiation protocol also enhanced
somatic embryo production. Somatic embryos of 93 embryogenic lines (representing five families) that were initiated on media
with different PGR concentrations were converted to plants at an overall frequency of 76%, and grown in the greenhouse. With
these improved protocols, application of P. strobus SE in commercial clonal forestry is feasible as an alternative to traditional breeding and reforestation. 相似文献
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A cell-free system from Andrographis paniculata tissue cultures catalysed the transesterification of administered cis, trans-farnesol-[1-3H2] with (glyceryl) oleate and palmitate present in the coconut water that forms part of the culture medium. 相似文献
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35.
EpoDB: a prototype database for the analysis of genes expressed during vertebrate erythropoiesis. 下载免费PDF全文
EpoDB is a database of genes expressed in vertebrate red blood cells. It is also a prototype for the creation of cell and tissue-specific databases from multiple external sources. The information in EpoDB obtained from GenBank, SWISS-PROT, Transfac, TRRD and GERD is curated to provide high quality data for sequence analysis aimed at understanding gene regulation during erythropoiesis. New protocols have been developed for data integration and updating entries. Using a BLAST-based algorithm, we have grouped GenBank entries representing the same gene together. This sequence similarity protocol was also used to identify new entries to be included in EpoDB. We have recently implemented our database in Sybase (relational tables) in addition to SICStus Prolog to provide us with greater flexibility in asking complex queries that utilize information from multiple sources. New additions to the public web site (http://www.cbil.upenn.edu/epodb) for accessing EpoDB are the ability to retrieve groups of entries representing different variants of the same gene and to retrieve gene expression data. The BLAST query has been enhanced by incorporating BLASTView, an interactive and graphical display of BLAST results. We have also enhanced the queries for retrieving sequence from specified genes by the addition of MEME, a motif discovery tool, to the integrated analysis tools which include CLUSTALW and TESS. 相似文献
36.
Matthew?J.?ColloffEmail authorView authors OrcID profile Ian?C.?Overton Brent?L.?Henderson Jane?Roberts Julian?R.?W.?Reid Roderick?L.?Oliver Anthony?D.?Arthur Tanya?M.?Doody Neil?C.?Sims Qifeng?Ye Susan?M.?Cuddy 《Aquatic Ecology》2018,52(1):133-153
Determination of ecological responses to river flows is fundamental to understanding how flow-dependent ecosystems have been altered by regulation, water diversions and climate change, and how to effect river restoration. Knowledge of ecohydrological relationships can support water management and policy, but this is not always the case. Management rules have tended to be developed ahead of scientific knowledge. The lag between practice and knowledge could be addressed by using historical monitoring data on ecological responses to changes in flows to determine significant empirical ecohydrological relationships, as an adjunct to investigating responses prospectively. This possibility was explored in the Murray–Darling Basin, Australia. We assessed 359 data sets collected during monitoring programs across the basin. Of these, only 32 (9%) were considered useful, based on a match between the scale at which sampling was done and ecological responses are likely to occur, and used to test flow–ecology predictions for phytoplankton, macroinvertebrates, fishes, waterbirds, floodplain trees, basin-scale vegetation and estuarine biota. We found relationships between flow and ecological responses were likely to be more strongly supported for large, long-lived, widespread biota (waterbirds, basin-scale vegetation, native fishes), than for more narrowly distributed (e.g. estuarine fishes) or smaller, short-lived organisms (e.g. phytoplankton, macroinvertebrates). This pattern is attributed to a mismatch between the design of monitoring programs and the response time frames of individual biota and processes, and to the use of local river discharge as a primary predictor variable when, for many biotic groups, other predictors need to be considered. 相似文献
37.
S.P. NG Z.G. LI B.W. CHEN Z.K. QIN M.M. GARCIA S.W.K. IM M.H. NG 《Journal of Rapid Methods and Automation in Microbiology》1997,5(4):285-294
We previously described an enrichment-immunoassay utilizing a T6 monoclonal antibody capture enzyme-linked immunosorbent assay. Here we evaluated it for the rapid screening for Salmonella in fishmeal obtained from the national Animal and Plant Quarantine service in the People's Republic of China. In this method, the number of Salmonella present is first expanded by appropriate enrichment cultures, and the pathogens are then directly detected by the T6 immunoassay. In a total of 94 enrichment cultures of fishmeal, we obtained an overall concordance of 98% between the results obtained in parallel by this method and by conventional test method. The positive prediction by this method was 92% and the negative prediction was 100%. The turn around time for the new test was 27 h which is a significant improvement from the turn around time exceeding 96 h required for the conventional test method. This test proved to be compatible with the routine work flow in the practical setting of a quarantine laboratory. 相似文献
38.
Jane Elith Catherine H. Graham Robert P. Anderson Miroslav Dudík Simon Ferrier Antoine Guisan Robert J. Hijmans Falk Huettmann John R. Leathwick Anthony Lehmann Jin Li Lucia G. Lohmann Bette A. Loiselle Glenn Manion Craig Moritz Miguel Nakamura Yoshinori Nakazawa Jacob McC. M. Overton A. Townsend Peterson Steven J. Phillips Karen Richardson Ricardo Scachetti-Pereira Robert E. Schapire Jorge Soberón Stephen Williams Mary S. Wisz Niklaus E. Zimmermann 《Ecography》2006,29(2):129-151
Prediction of species' distributions is central to diverse applications in ecology, evolution and conservation science. There is increasing electronic access to vast sets of occurrence records in museums and herbaria, yet little effective guidance on how best to use this information in the context of numerous approaches for modelling distributions. To meet this need, we compared 16 modelling methods over 226 species from 6 regions of the world, creating the most comprehensive set of model comparisons to date. We used presence-only data to fit models, and independent presence-absence data to evaluate the predictions. Along with well-established modelling methods such as generalised additive models and GARP and BIOCLIM, we explored methods that either have been developed recently or have rarely been applied to modelling species' distributions. These include machine-learning methods and community models, both of which have features that may make them particularly well suited to noisy or sparse information, as is typical of species' occurrence data. Presence-only data were effective for modelling species' distributions for many species and regions. The novel methods consistently outperformed more established methods. The results of our analysis are promising for the use of data from museums and herbaria, especially as methods suited to the noise inherent in such data improve. 相似文献
39.
The biological responses to caloric restriction (CR) are generally examined in rats with elevated metabolic rates due to being housed at ambient temperatures (T(a)) below the zone of thermoneutrality. We determined the physiological and behavioral responses to 2 wk of 30-40% CR in male FBNF1 rats housed in cool (T(a) = 12 degrees C) or thermoneutral (TMN; T(a) = 30 degrees C) conditions. Rats were instrumented with telemetry devices and housed continuously in home-cage calorimeters for the entire experiment. At baseline, rats housed in cool T(a) had reduced rate of weight gain; thus a mild CR (5%) group at thermoneutrality for weight maintenance was also studied. Rats housed in cool T(a) exhibited elevated caloric intake (cool = 77 +/- 1; TMN = 54 +/- 2 kcal), oxygen consumption (Vo(2); cool = 9.9 +/- 0.1; TMN = 5.5 +/- 0.1 ml/min), mean arterial pressure (cool = 103 +/- 1; TMN = 80 +/- 2 mmHg), and heart rate (cool = 374 +/- 3; TMN = 275 +/- 4 beats/min). Cool-CR rats exhibited greater CR-induced weight loss (cool = -62 +/- 3; TMN = -42 +/- 3 g) and reductions in Vo(2) (cool = -2.6 +/- 0.1; TMN = -1.5 +/- 0.1 ml/min) but similar CR-induced reductions in heart rate (cool = -59 +/- 1; TMN= -51 +/- 7 beats/min). CR had no effect on arterial blood pressure or locomotor activity in either group. Unexpectedly, weight maintenance produced significant reductions in Vo(2) and heart rate. At thermoneutrality, a single day of refeeding effectively abolished CR-induced reductions in Vo(2) and heart rate. The results reveal that rats with low or high baseline metabolic rate exhibit comparable compensatory reductions in Vo(2) and heart rate and suggest that T(a) can be used to modulate the metabolic background on which the more prolonged effects of CR can be studied. 相似文献
40.
Desmond A. Mackell Michael L. Casazza Cory T. Overton J. Patrick Donnelly David Olson Fiona McDuie Joshua T. Ackerman John M. Eadie 《Ecology and evolution》2021,11(20):14056
Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS‐GSM transmitters, we analyzed 61 fall migration tracks across western North America during our three‐year study (2017–2019). We marked Cinnamon Teal primarily during spring/summer in important breeding and molting regions across seven states (California, Oregon, Washington, Idaho, Utah, Colorado, and Nevada). We assessed fall migration routes and timing, detected 186 fall stopover sites, and identified specific North American ecoregions where sites were located. We classified underlying land cover for each stopover site and measured habitat selection for 12 land cover types within each ecoregion. Cinnamon Teal selected a variety of flooded habitats including natural, riparian, tidal, and managed wetlands; wet agriculture (including irrigation ditches, flooded fields, and stock ponds); wastewater sites; and golf and urban ponds. Wet agriculture was the most used habitat type (29.8% of stopover locations), and over 72% of stopover locations were on private land. Relatively scarce habitats such as wastewater ponds, tidal marsh, and golf and urban ponds were highly selected in specific ecoregions. In contrast, dry non‐habitat across all ecoregions, and dry agriculture in the Cold Deserts and Mediterranean California ecoregions, was consistently avoided. Resources used by Cinnamon Teal often reflected wetland availability across the west and emphasize their adaptability to dynamic resource conditions in arid landscapes. Our results provide much needed information on spatial and temporal resource use by Cinnamon Teal during migration and indicate important wetland habitats for migrating waterfowl in the western United States. 相似文献