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Barbara D. Abbott Robert M. Pratt 《In vitro cellular & developmental biology. Plant》1988,24(4):343-352
Summary Retinoids and growth factors seem to be important for normal mammalian reproduction and development. High levels of retinoic
acid are teratogenic and induce cleft palate in the mouse. Little is known concerning the mechanisms through which retinoids
induce cleft palate. Palatal epithelia from CD-1 embryonic mice on Day 12 of gestation were isolated from the mesenchyme and
cultured in serum-free media, with all-trans retinoic acid or 13-cis retinoic acid, with or without epidermal growth factor
(EGF). The epithelia attached and grew, and the cells differentiated over a 72-h culture period. Binding of [125I]EGF was observed in all cultures in a pattern that correlated with thymidine (TdR) uptake by the epithelia. EGF enhanced
growth and [3H]TdR incorporation of the oral cells, but nasal cells generally did not proliferate. In this culture system, both retinoids
suppressed [3H]TdR incorporation in a concentration-dependent manner for epithelia cultured with or without EGF. Medial cells are important
to normal palatogenesis as they play a role in fusion of opposing shelves and subsequently many of these cells undergo programmed
cell death. Death of medial cells in vitro is prevented by EGF and by the retinoids, either with or without EGF. This response
occurs in the absence of a mesenchymal interaction, suggesting that the medial cell response to EGF and retinoids is not mediated
by or dependent on the mesenchymal tissues. The survival of medial cells may be responsible for the failure of opposing shelves
to fuse. 相似文献
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Piotr Politański Elźbieta Rajkowska Marcin Brodecki Andrzej Bednarek Marek Zmyślony 《Bioelectromagnetics》2013,34(4):333-336
The aim of this study was to investigate the effect of static magnetic fields (SMF) on reactive oxygen species induced by X‐ray radiation. The experiments were performed on lymphocytes from male albino Wistar rats. After exposure to 3 Gy X‐ray radiation (with a dose rate of 560 mGy/min) the measurement of intracellular reactive oxygen species in lymphocytes, using a fluorescent probe, was done before exposure to the SMF, and after 15 min, 1 and 2 h of exposure to the SMF or a corresponding incubation time. For SMF exposure, 0 mT (50 µT magnetic field induction opposite to the geomagnetic field) and 5 mT fields were chosen. The trend of SMF effects for 0 mT was always opposite that of 5 mT. The first one decreased the rate of fluorescence change, while the latter one increased it. Bioelectromagnetics 34:333–336, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
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Marta Bassitta Joana M. Buades Ana Pérez-Cembranos Valentín Pérez-Mellado Barbara Terrasa Richard P. Brown Pilar Navarro Javier Lluch Jesús Ortega Jose A. Castro Antònia Picornell Cori Ramon 《Zoologica scripta》2020,49(6):668-683
The phylogenetic relationships among the wall lizards of the Podarcis hispanicus complex that inhabit the south-east (SE) of the Iberian Peninsula and other lineages of the complex remain unclear. In this study, four mitochondrial and two nuclear markers were used to study genetic relationships within this complex. The phylogenetic analyses based on mtDNA gene trees constructed with ML and BI, and a species tree using *BEAST support three divergent clades in this region: the Valencia, Galera and Albacete/Murcia lineages. These three lineages were also corroborated in species delimitation analyses based on mtDNA using bPTP, mPTP, GMYC, ABGD and BAPS. Bayesian inference species delimitation method (BPP) based on both nuclear data and a combined data set (mtDNA + nuclear) showed high posterior probabilities for these three SE lineages (≥0.94) and another Bayesian analysis (STACEY) based on combined data set recovered the same three groups in this region. Divergence time dating of the species tree provided an estimated divergence of the Galera lineage from the other SE group (Podarcis vaucheri, (Albacete/Murcia, Valencia)) at 12.48 Ma. During this period, the Betic–Rifian arc was isolated, which could have caused the isolation of the Galera form distributed to the south of the Betic Corridor. Although lizards from the Albacete/Murcia and Galera lineage are morphologically similar, they clearly represent distinct genetic lineages. The noteworthy separation of the Galera lineage enables us to conclude that this lineage must be considered as a new full species. 相似文献