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91.
It was shown that the 250-fold screening of the geomagnetic field (GMF) (“zero” magnetic field with an induction of 0.2?μT) affects early embryogenesis and the reproduction capacity of mice in vivo. Pregnant NMRI mice at the zygote stage placed in this “zero” magnetic field (MF) lost the ability to bear offspring babies although their embryos developed up to the blastocyst stage without any visible deviations from the norm. The abortion of development in the “zero” MF occurred after the exit of the blastocysts from the zona pellicida and invasion into the uterus during implantation. Histological analysis indicates that possible reasons of the abnormalities of postimplantation development are a decrease in the proliferative activity of embryonic cells and the impairment of the interaction between the trophoblast and endometrium, which finally results in the resorption of embryos in the uterus.  相似文献   
92.
Embryogenesis in cotton is a difficult task due its genome dependency. We used 3 cotton cultivars (Khandwa-2, G. Cot. 10, and BC-68–2) and Coker-312 as control for regeneration. Efficient somatic embryogenesis was induced in agronomically important Indian cotton cultivars, Khandwa-2 and G. Cot. 10. For callusing in all the cultivars, different media combinations were tried. Embryogenesis was initiated on a hormone-free MS medium (MSB). For embryo maturation and recovery excess of L-glutamine and l-asparagine were used. Khandwa-2 somatic embryos were successfully regenerated into plants. However, no plantlet was obtained in case of G. Cot. 10. Callus induction was also observed in BC-68–2 but there was no embryogenesis observed. The study indicated that the medium and genotype significantly effects embryogenesis. An efficient protocol is described here for regenerating plants via somatic embryogenesis in an elite Indian cotton cultivar Khandwa-2.  相似文献   
93.
In eukaryotic cells short-lived proteins are degraded in a specific process by the ubiquitin-proteasome system (UPS), whereas long-lived proteins and damaged organelles are degraded by macroautophagy (hereafter referred to as autophagy). A growing body of evidence now suggests that autophagy is important for clearance of protein aggregates that form in cells as a consequence of ageing, oxidative stress, alterations that elevate the amounts of certain aggregation-prone proteins or expression of aggregating mutant variants of specific proteins. Autophagy is generally considered to be a non-specific, bulk degradation process. However, a recent study suggests that p62/SQSTM1 may link the recognition of polyubiquitinated protein aggregates to the autophagy machinery.1 This protein is able to polymerize via its N-terminal PB1 domain and to recognize polyubiquitin via its C-terminal UBA domain. It can also recruit the autophagosomal protein LC3 and co-localizes with many types of polyubiquitinated protein aggregates.1 Here we discuss possible implications of these findings and raise some questions for further investigation.  相似文献   
94.
The use of medicinal plants for different therapeutic values is well documented in African continent. African diverse biodiversity hotspots provide a wide range of endemic species, which ensures a potential medicinal value. The feasible conservation approach and sustainable harvesting for the medicinal species remains a huge challenge. However, conservation approach through different biotechnological tools such as micropropagation, somatic embryogenesis, synthetic seed production, hairy root culture, molecular markers based study and cryopreservation of endemic African medicinal species is much crucial. In this review, an attempt has been made to provide different in vitro biotechnological approaches for the conservation of African medicinal species. The present review will be helpful in further technology development and deciding the priorities at decision-making levels for in vitro conservation and sustainable use of African medicinal species.  相似文献   
95.
Late Embryogenesis Abundant (LEA) proteins are commonly found in plants and other organisms capable of undergoing severe and reversible dehydration, a phenomenon termed “anhydrobiosis”. Here, we have produced a tagged version for three different LEA proteins: pTag-RAB17-GFP-N, Zea mays dehydrin-1dhn, expressed in the nucleo-cytoplasm; pTag-WCOR410-RFP, Tricum aestivum cold acclimation protein WCOR410, binds to cellular membranes, and pTag-LEA-BFP, Artemia franciscana LEA protein group 3 that targets the mitochondria. Sheep fibroblasts transfected with single or all three LEA proteins were subjected to air drying under controlled conditions. After rehydration, cell viability and functionality of the membrane/mitochondria were assessed. After 4 h of air drying, cells from the un-transfected control group were almost completely nonviable (1% cell alive), while cells expressing LEA proteins showed high viability (more than 30%), with the highest viability (58%) observed in fibroblasts expressing all three LEA proteins. Growth rate was markedly compromised in control cells, while LEA-expressing cells proliferated at a rate comparable to non-air-dried cells. Plasmalemma, cytoskeleton and mitochondria appeared unaffected in LEA-expressing cells, confirming the protection conferred by LEA proteins on these organelles during dehydration stress. This is likely to be an effective strategy when aiming to confer desiccation tolerance to mammalian cells.  相似文献   
96.
Summary

In insects, the regulation of embryonic development has been intensively studied in model species like Drosophila melanogaster. Previous comparative studies have suggested that the developmental processes documented in Drosophila well describe embryogenesis of holometabolous insects generally. However, there have been few attempts to take into account how life history has influenced insect embryogenesis or to characterize early development of species with life histories fundamentally different from flies. Our studies of advanced insects in the order Hymenoptera suggest that punctuated shifts in life history can profoundly influence these events. In particular, alterations associated with the evolution of endoparasitism argue that departures from the fly paradigm may occur commonly among insects that develop under conditions different from typical terrestrial species.  相似文献   
97.
Nowadays heat-sensitive protein medicines are increasingly showing their importance in the treatment of various diseases. Their popularisation and application are meeting a great challenge because of their heat lability. In this study, human insulin as a heat-sensitive protein medicine and 66 amino acids derived from a Group 3 late embryogenesis abundant protein fragment as a complex bioactive protectant, were chosen to be investigated to determine whether these amino acids can be used to protect the insulin from denaturation due to drying. The experiments were carried out by using a replica exchange molecular dynamics (REMD) simulation and GROMACS software with Gromos96 (53a6) force field. The REMD results indicate that those amino acids can effectively prevent the reversal between hydrophilic and hydrophobic surface. Both the configurations and secondary structures of the protected insulin were preserved very well. The H-bonding and electrostatic interactions between the insulin and the protectant play key roles in the bioactive protection of insulin. These results agree well with the water replacement hypothesis. All the results prove that these amino acids are a perfect bioactive protectant for heat-sensitive protein medicines.  相似文献   
98.
99.
Tabernaemontana alba and Tabernaemontana arborea are Apocynaceae species used in Mexican traditional medicine for which little phytochemical information exists. In this study, preliminary gas chromatography/mass spectrometry analyses of different organs obtained from wild plants of both species identified a total of 10 monoterpenoid indole alkaloids (MIAs) and one simple indole alkaloid, nine of which were reported for the first time in these species. Furthermore, callus cultures were established from T. alba leaf explants and regeneration of whole plants was accomplished via somatic embryogenesis. The anti‐addictive MIAs ibogaine and voacangine were then quantified by gas chromatography with flame ionization detection in wild plants of both species, as well as greenhouse‐grown plants, in vitro‐grown plantlets and embryogenic callus of T. alba. Ibogaine and voacangine were present in most samples taken from the whole plants of both species, with stem and root barks showing the highest concentrations. No alkaloids were detected in callus samples. It was concluded that T. alba and T. arborea are potentially viable sources of ibogaine and voacangine, and that these MIAs can be produced through somatic embryogenesis and whole plant regeneration of T. alba. Approaches to increase MIA yields in whole plants and to achieve alkaloid production directly in cell cultures are discussed.  相似文献   
100.
Eukaryotes have evolved an array of membrane compartments constituting secretory and endocytic pathways that allow the flow of materials. Both pathways perform important regulatory roles. The secretory pathway is essential for the production of extracellular, secreted signal molecules, but its function is not restricted to a mere route connecting intra‐ and extracellular compartments. Post‐translational modifications also play an integral function in the secretory pathway and are implicated in developmental regulation. The endocytic pathway serves as a platform for relaying signals from the extracellular stimuli to intracellular mediators, and then ultimately inducing signal termination. Here, we discuss recent studies showing that dysfunction in membrane dynamics causes patterning defects in embryogenesis and tissue morphogenesis in mammals. Birth Defects Research (Part C) 108:33–44, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   
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