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71.
Wollenhaupt K Reinke K Brüssow KP Kanitz W Tomek W 《Molecular reproduction and development》2011,78(12):895-905
The implantation of the blastocyst into the endometrium is an indispensable premise for successful embryonic development. This process is regulated by maternal and embryonic signals that influence gene expression at the translational level, among other processes. Recently, we have shown that proteolytical cleavage of the prototypical 25‐kDa, mRNA cap‐binding protein eIF4E produces a stable variant with a molecular mass of approximately 23 kDa exclusively in the porcine endometrium during implantation. This is accompanied by dephosphorylation and reduction of the abundant repressor 4E‐BP1. Here, we investigate the distribution of the truncated eIF4E and of 4E‐BP1 in the porcine uterine tissue, their binding in native samples, and we analyzed eIF4E‐, eIF4G‐, and 4E‐BP1‐specific proteolytic activities. Our results show that in pigs, the truncated eIF4E is located in the endometrial luminal epithelium during implantation. Neither glandulary tissue nor stroma expressed any truncated eIF4E. The reduced abundance of 4E‐BP1 during implantation is mainly the result of decay in the glandular epithelia. Moreover, steroid replacements, in vitro protease assays, and cell lysate fractionation showed that eIF4E cleavage and 4E‐BP1 decay both depended on the ovarian steroid hormones estradiol and progestrone, but these effects are the result of different proteolytic activities. Although eIF4G cleavage also depends on calcium, stimulation by these steroids could not be established. We propose that the translation initiation process in the endometrium is differently regulated by the truncated eIF4E, utilizing different abundances of 4E‐BP1 and binding dynamic of eIF4E/4E‐BP1 in distinct forms of implantation. Mol. Reprod. Dev. 78:895–905, 2011. © 2011 Wiley Periodicals, Inc. 相似文献
72.
Cryopreservation of Digitalis lanata Ehrh. cell cultures: Preculture and freeze tolerance 总被引:4,自引:0,他引:4
Cryopreservation experiments were performed with Digitalis lanata cell cultures. The main stress was laid on the behaviour of the cells during the preculture period and the capacity of various preculture additives to induce freeze tolerance. The following compounds were used as preculture additives: trehalose, mannitol, sucrose, melibiose, proline, and sorbitol. They are listed in the order of their respective efficiency. Using trehalose, high post-thaw viability rates were achieved and the cells resumed growth after a short lag period. Melibiose was used as a preculture additive for the first time. Its suitability was in the range of that of sucrose. Proline and sorbitol were not able to induce freeze tolerance in Digitalis cells. Cell viability showed a considerable decrease at the beginning of the preculture period. This reduction was found to be transient in the presence of trehalose, mannitol, sucrose, and melibiose. The damaging effects of proline and sorbitol were too severe to be compensated for by the cells. The PAL activity increased markedly in the presence of proline, whereas the trehalose-treated and the control cells behaved nearly identical to one another. 相似文献
73.
Stimulation by 6-N,2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate and glucocorticoids of phosphoenolpyruvate carboxykinase in the isolated perfused rat liver (Short Communication) 下载免费PDF全文
Wieland B. Huttner Wilhelm Krone Hans J. Seitz Wolfgang Tarnowski 《The Biochemical journal》1974,142(3):691-693
Dibutyryl cyclic AMP stimulated the activity of phosphoenolpyruvate carboxykinase in perfused livers of rats, fed on a low-protein diet, linearly over a 6h period. The enzyme activity was also significantly elevated by dexamethasone, the effect being considerably lower than that of the cyclic nucleotide. Since the time-course of phosphoenolpyruvate carboxykinase activity in response to dibutyryl cyclic AMP resembled that observed after dibutyryl cyclic AMP injection into intact animals, it is suggested that induction of the enzyme in vivo is due to a direct action of the cyclic nucleotide on the liver. Combined administration of dibutyryl cyclic AMP and glucocorticoids did not lead to an additive increase of liver phosphoenolpyruvate carboxykinase activity, either in vivo or in the perfused organ. 相似文献
74.
Two formerly geographically separated lineages of the zebra mussel Dreissena polymorpha had been given the opportunity to mix extensively across the newly built German Main–Danube canal. We had monitored this admixture of mussel lineages and had described spatial patterns in different genetic measures [Müller et al. 2001 (Heredity, 86: 103); 2002 (Proc. R. Soc. Lond., 269: 1139)]. Here, we present an individual-based model to assess the potential of spatial genetic patterns of detecting and quantifying admixture of mussel lineages. Genetic measures studied are (1) allele frequencies, (2) deviations from Hardy–Weinberg expectations of loci (deficit of heterozygotes, HWD) and (3) linkage disequilibria between unlinked loci (LD). For allele frequencies, we observed a cline over the zone of admixture in all simulations of mixing mussel lineages suggesting that these are appropriate for verification of their mixture. The point of the first contact between lineages was always detectable from their intermediate allele frequencies. LD and HWD were only spatially informative for diagnostic loci or loci with very strong differences in allele frequencies of lineages. For such loci, the probability of disequilibria was highest where lineages had met and decreased towards both sources of lineages Main and Danube. The overall probability of detecting any disequilibrium was higher for LD than for HWD and increased with an increasing rate of genetic interchange. Our simulation results are corroborated by our zebra mussel data and studies from literature. They are applicable to any case of two known linearly mixing genetic lineages. 相似文献
75.
Ras-independent activation of the Raf/MEK/ERK pathway upon calcium-induced differentiation of keratinocytes 总被引:4,自引:0,他引:4
Schmidt M Goebeler M Posern G Feller SM Seitz CS Brocker EB Rapp UR Ludwig S 《The Journal of biological chemistry》2000,275(52):41011-41017
MAPKs are crucially involved in the regulation of growth and differentiation of a variety of cells. To elucidate the role of MAPKs in keratinocyte differentiation, activation of ERK, JNK, and p38 in response to stimulation with extracellular calcium was analyzed. We provide evidence that calcium-induced differentiation of keratinocytes is associated with rapid and transient activation of the Raf/MEK/ERK pathway. Stimulation of keratinocytes with extracellular calcium resulted in activation of Raf isozymes and their downstream effector ERK within 10-15 min, but did not increase JNK or p38 activity. Calcium-induced ERK activation differed in kinetics from mitogenic ERK activation by epidermal growth factor and could be modulated by alterations of intracellular calcium levels. Interestingly, calcium stimulation led to down-regulation of Ras activity at the same time that ERK activation was initiated. Expression of a dominant-negative mutant of Ras also did not significantly impair calcium-induced ERK activation, indicating that calcium-mediated ERK activation does not require active Ras. Despite the transient nature of ERK activation, calcium-induced expression of the cyclin-dependent kinase inhibitor p21/Cip1 and the differentiation marker involucrin was sensitive to MEK inhibition, which suggests a role for the Raf/MEK/ERK pathway in early stages of keratinocyte differentiation. 相似文献
76.
Andreja Radović Vassiliki Kati Melita Perčec Tadić Damijan Denac Dražen Kotrošan 《Bird Study》2013,60(1):106-114
Capsule Spatial environmental modelling well predicted nesting distribution of the White stork in Southeast Europe and can be used in conservation planning with respect to climate change.Aims To create spatial models for predicting White Stork presence and densities in the Southeast Europe to identify areas of suitable habitat for White Storks.Methods We quantified the habitat used by nesting White storks in Southeast Europe. Using spatial modelling, we defined a set of free and available online environmental variables that predict the breeding localities of the species. We employed pseudo-absences and the kriging of the residuals in order to create predictive models of nest presence and density.Results The presence–absence model was found to be precise in predicting the presence of nests. Both density and presence of breeding pairs were best explained negatively by elevation, slope, minimum temperature during May, and distance to the nearest human settlement and positively by topographic wetness index, total area of human settlement and spring precipitation.Conclusion Our robust and easily repeatable models offer a conservation tool to reveal suitable but unoccupied localities for breeding White Storks pairs which may inform our understanding of how climate change might affect the species' distribution in the future. For example, protecting White Storks on the Dalmatian coast may become even more significant in the future, because the Dalmatian coast is predicted as the only suitable breeding area in Croatia later this century. 相似文献
77.
Pablo Cerme?o Gemma Quílez-Badia Andrés Ospina-Alvarez Susana Sainz-Trápaga Andre M. Boustany Andy C. Seitz Sergi Tudela Barbara A. Block 《PloS one》2015,10(2)
We analyzed the movements of Atlantic tuna (Thunnus thynnus L.) in the Mediterranean Sea using data from 2 archival tags and 37 pop-up satellite archival tags (PAT). Bluefin tuna ranging in size from 12 to 248 kg were tagged on board recreational boats in the western Mediterranean and the Adriatic Sea between May and September during two different periods (2000 to 2001 and 2008 to 2012). Although tuna migrations between the Mediterranean Sea and the Atlantic Ocean have been well reported, our results indicate that part of the bluefin tuna population remains in the Mediterranean basin for much of the year, revealing a more complex population structure. In this study we demonstrate links between the western Mediterranean, the Adriatic and the Gulf of Sidra (Libya) using over 4336 recorded days of location and behavior data from tagged bluefin tuna with a maximum track length of 394 days. We described the oceanographic preferences and horizontal behaviors during the spawning season for 4 adult bluefin tuna. We also analyzed the time series data that reveals the vertical behavior of one pop-up satellite tag recovered, which was attached to a 43.9 kg tuna. This fish displayed a unique diving pattern within 16 days of the spawning season, suggesting a use of the thermocline as a thermoregulatory mechanism compatible with spawning. The results obtained hereby confirm that the Mediterranean is clearly an important habitat for this species, not only as spawning ground, but also as an overwintering foraging ground. 相似文献
78.
Heli Elovaara Teija Huusko Mikael Maksimow Kati Elima Gennady G. Yegutkin Mikael Skurnik Ulrich Dobrindt Anja Siitonen Michael J. McPherson Marko Salmi Sirpa Jalkanen 《PloS one》2015,10(11)
Escherichia coli amine oxidase (ECAO), encoded by the tynA gene, catalyzes the oxidative deamination of aromatic amines into aldehydes through a well-established mechanism, but its exact biological role is unknown. We investigated the role of ECAO by screening environmental and human isolates for tynA and characterizing a tynA-deletion strain using microarray analysis and biochemical studies. The presence of tynA did not correlate with pathogenicity. In tynA+ Escherichia coli strains, ECAO enabled bacterial growth in phenylethylamine, and the resultant H2O2 was released into the growth medium. Some aminoglycoside antibiotics inhibited the enzymatic activity of ECAO, which could affect the growth of tynA+ bacteria. Our results suggest that tynA is a reserve gene used under stringent environmental conditions in which ECAO may, due to its production of H2O2, provide a growth advantage over other bacteria that are unable to manage high levels of this oxidant. In addition, ECAO, which resembles the human homolog hAOC3, is able to process an unknown substrate on human leukocytes. 相似文献
79.
Sara Sammallahti Marius Lahti Riikka Pyh?l? Jari Lahti Anu-Katriina Pesonen Kati Heinonen Petteri Hovi Johan G. Eriksson Sonja Strang-Karlsson Anna-Liisa J?rvenp?? Sture Andersson Eero Kajantie Katri R?ikk?nen 《PloS one》2015,10(9)
Objectives
Faster growth after preterm birth benefits long-term cognitive functioning. Whether these benefits extend to mental health remains largely unknown. We examined if faster growth in infancy is associated with better self-reported mental health in young adults born preterm at very low birth weight (VLBW) (<1500g).Study Design
As young adults, participants of the Helsinki Study of Very Low Birth Weight Adults self-reported symptoms of depression and attention deficit/hyperactivity disorder (ADHD) (n = 157) and other psychiatric problems (n = 104). As main predictors of mental health outcomes in linear regression models, we used infant weight, length, and head circumference at birth, term, and 12 months of corrected age, and growth between these time points. Growth data were collected from records and measures at term and at 12 months of corrected age were interpolated. Additionally, we examined the moderating effects of intrauterine growth restriction.Results
Size at birth, term, or 12 months of corrected age, or growth between these time points were not associated with mental health outcomes (p-values >0.05). Intrauterine growth restriction did not systematically moderate any associations.Conclusions
Despite the high variability in early growth of VLBW infants, the previously described association between slow growth in infancy and poorer cognitive functioning in later life is not reflected in symptoms of depression, ADHD, and other psychiatric problems. This suggests that the development of cognitive and psychiatric problems may have dissimilar critical periods in VLBW infants. 相似文献80.
Maria A. Lankinen Kati Hanhineva Marjukka Kolehmainen Marko Lehtonen Seppo Auriola Hannu Mykk?nen Kaisa Poutanen Ursula Schwab Matti Uusitupa 《PloS one》2015,10(4)