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991.
R. Timothy Mulcahy Wayne A. Rosenkrans Jr. David P. Penney Robert A. Cooper 《In vitro cellular & developmental biology. Plant》1985,21(9):513-520
Summary FRTL-5 cells, a diploid line of differentiated rat thyroid epithelial cells, have been grown as multicellular spheroids in
spinner culture. Spheroids were initiated by seeding FRTL-5 cells either into Lab-Tek dishes or culture flasks with a 0.5%
agar base. Thyroid stimulating hormone (TSH, >1.0 mU/ml) was required for initial cell aggregation and spheroid growth. After
1 wk cellular aggregates were transferred to suspension culture in spinner flasks. As with FRTL-5 monolayer cultures, continued
spheroid growth required the addition of TSH to the culture medium. The most unique characteristic of the FRTL-5 spheroids
was the development of central lumina similar to thyroid follicles in vivo. Follicular structures were absent from spheroids
not stimulated with TSH. In the presence of TSH epithelial cells seem metabolically active with morphological evidence of
biosynthesis of thyroglobulin-like material and basal laminar-like components. In contrast, all evidence of cellular metabolic
activity is absent from cells in spheroids maintained in the absence of TSH. Thus, nontransformed FRTL-5 cells grown as three-dimensional
multicellular spheroids responded to hormonal manipulation in a manner comparable to follicular epithelial cells in vivo.
This spheroid model might therefore prove to be a very effective tool for investigating aspects of thyroid physiology and
pathology in vitro.
This work was supported by Grant CA-11198 and CA-20329 awarded by the National Institutes of Health, and a Biomedical Research
Support Grant awarded to R. T. Mulcahy. 相似文献
992.
Burks Christian; Fickett James W.; Goad Walter B.; Kanehisa Minoru; Lewitter Frances I.; Rindone Wayne P.; Swindell C. David; Tung Chang-Shung; Bilofsky Howard S. 《Bioinformatics (Oxford, England)》1985,1(4):225-233
The GenBank* nucleic acid sequence database isa computer-based collection of all published DNA and RNA sequences;it contains over five million bases in close to six thousandsequence entries drawn from four thousand five hundred publishedarticles. Each sequence is accompanied by relevant biologicalannotation. The database is available either on magnetic tape,on floppy diskettes, on-line or in hardcopy form. We discussthe structure of the database, the extent of the data and theimplications of the database for research on nucleic acids. 相似文献
993.
Checinska Sielaff Aleksandra Upton Racheal N. Hofmockel Kirsten S. Xu Xia Polley H. Wayne Wilsey Brian J. 《Plant and Soil》2018,432(1-2):359-372
Plant and Soil - Grasslands dominated by non-native (exotic) species have replaced purely native-dominated areas in many parts of the world forming ‘novel’ ecosystems. Altered... 相似文献
994.
995.
Local and cross‐seasonal associations of climate and land use with abundance of monarch butterflies Danaus plexippus 下载免费PDF全文
Sarah P. Saunders Leslie Ries Karen S. Oberhauser Wayne E. Thogmartin Elise F. Zipkin 《Ecography》2018,41(2):278-290
Quantifying how climate and land use factors drive population dynamics at regional scales is complex because it depends on the extent of spatial and temporal synchrony among local populations, and the integration of population processes throughout a species’ annual cycle. We modeled weekly, site‐specific summer abundance (1994–2013) of monarch butterflies Danaus plexippus at sites across Illinois, USA to assess relative associations of monarch abundance with climate and land use variables during the winter, spring, and summer stages of their annual cycle. We developed negative binomial regression models to estimate monarch abundance during recruitment in Illinois as a function of local climate, site‐specific crop cover, and county‐level herbicide (glyphosate) application. We also incorporated cross‐seasonal covariates, including annual abundance of wintering monarchs in Mexico and climate conditions during spring migration and breeding in Texas, USA. We provide the first empirical evidence of a negative association between county‐level glyphosate application and local abundance of adult monarchs, particularly in areas of concentrated agriculture. However, this association was only evident during the initial years of the adoption of herbicide‐resistant crops (1994–2003). We also found that wetter and, to a lesser degree, cooler springs in Texas were associated with higher summer abundances in Illinois, as were relatively cool local summer temperatures in Illinois. Site‐specific abundance of monarchs averaged approximately one fewer per site from 2004–2013 than during the previous decade, suggesting a recent decline in local abundance of monarch butterflies on their summer breeding grounds in Illinois. Our results demonstrate that seasonal climate and land use are associated with trends in adult monarch abundance, and our approach highlights the value of considering fine‐resolution temporal fluctuations in population‐level responses to environmental conditions when inferring the dynamics of migratory species. 相似文献
996.
Genome‐wide expression reveals multiple systemic effects associated with detection of anticoagulant poisons in bobcats (Lynx rufus) 下载免费PDF全文
Devaughn Fraser Laurel E. K. Serieys Steve Cole Scott Carver Sue Vandewoude Michael Lappin Seth P.D. Riley Robert Wayne 《Molecular ecology》2018,27(5):1170-1187
Anticoagulant rodenticides (ARs) are indiscriminate toxicants that threaten nontarget predatory and scavenger species through secondary poisoning. Accumulating evidence suggests that AR exposure may have disruptive sublethal consequences on individuals that can affect fitness. We evaluated AR‐related effects on genome‐wide expression patterns in a population of bobcats in southern California. We identify differential expression of genes involved in xenobiotic metabolism, endoplasmic reticulum stress response, epithelial integrity and both adaptive and innate immune function. Further, we find that differential expression of immune‐related genes may be attributable to AR‐related effects on leucocyte differentiation. Collectively, our results provide an unprecedented understanding of the sublethal effects of AR exposure on a wild carnivore. These findings highlight potential detrimental effects of ARs on a wide variety of species worldwide that may consume poisoned rodents and indicate the need to investigate gene expression effects of other toxicants added to natural environments by humans. 相似文献
997.
Kai Gerlach Scott Hobson Christian Eickmeier Ulrike Groß Clemens Braun Peter Sieger Michel Garneau Stefan Hoerer Niklas Heine 《Bioorganic & medicinal chemistry》2018,26(12):3227-3241
The identification and optimization of a novel series of centrally efficacious gamma secretase modulators (GSMs) offering an alternative to the privileged aryl imidazole motif is described. Chiral bicyclic tetrahydroindazolyl amine substituted triazolopyridines were identified as structurally distinct novel series of GSMs. Representative compound BI-1408 ((R)-42) was demonstrated to be centrally efficacious in rats at a 30?mg/kg oral dose. 相似文献
998.
999.
Susan C. Fitzer Sergio Torres Gabarda Luke Daly Brian Hughes Michael Dove Wayne O'Connor Jaimie Potts Peter Scanes Maria Byrne 《Ecology and evolution》2018,8(17):8973-8984
Ocean acidification is occurring globally through increasing CO2 absorption into the oceans creating particular concern for calcifying species. In addition to ocean acidification, near shore marine habitats are exposed to the deleterious effects of runoff from acid sulfate soils which also decreases environmental pH. This coastal acidification is being exacerbated by climate change‐driven sea‐level rise and catchment‐driven flooding. In response to reduction in habitat pH by ocean and coastal acidification, mollusks are predicted to produce thinner shells of lower structural integrity and reduced mechanical properties threatening mollusk aquaculture. Here, we present the first study to examine oyster biomineralization under acid sulfate soil acidification in a region where growth of commercial bivalve species has declined in recent decades. Examination of the crystallography of the shells of the Sydney rock oyster, Saccostrea glomerata, by electron back scatter diffraction analyses revealed that the signal of environmental acidification is evident in the structure of the biomineral. Saccostrea glomerata, shows phenotypic plasticity, as evident in the disruption of crystallographic control over biomineralization in populations living in coastal acidification sites. Our results indicate that reduced sizes of these oysters for commercial sale may be due to the limited capacity of oysters to biomineralize under acidification conditions. As the impact of this catchment source acidification will continue to be exacerbated by climate change with likely effects on coastal aquaculture in many places across the globe, management strategies will be required to maintain the sustainable culture of these key resources. 相似文献
1000.
The activation of ribulose1, 5-bisphosphate carb-oxylase/oxygenase(Rubisco, EC 4.1.1.39
[EC]
) from the floating angiosperm Spirodelapolyrhiza (L.) Schleid. (giant duckweed) grown at a photon irradianceof 200 or 400 mol photons m2 s1 was consistentlylow, in the range of 5662%. Similarly low values wereobserved with four other emergent aquatic species growing underfull sun irradiance. Transference of Spirodela plants for short(minutes) or long (days) periods to the higher or lower irradianceincreased or decreased, respectively, the activation by onlyabout 15%. Activation was not greatly altered by exposure ofthe plants to full sun irradiance of >2000 mol photons m2s1 or CO2 concentrations in air of 0 and 1170 mol mor1but darkness caused a slow decline to 20% activation. Transientoscillations were observed following a change in irradianceor CO2 concentration indicating that Rubisco was responsiveto environmental perturbations. The low Rubisco activation wasnot due to the tight binding of inhibitors such as carboxyarabinitol-1-phosphate.It is concluded that a substantial proportion of the Rubiscoprotein in these naturally-occurring species may not be usedfor CO2-fixation at any given moment. Key words: Rubisco 相似文献