scholarly journals Small nuclear ribonucleoproteins and heterogeneous nuclear ribonucleoproteins in the amphibian germinal vesicle: loops, spheres, and snurposomes.

1991 ◽  
Vol 113 (3) ◽  
pp. 465-483 ◽  
Author(s):  
Z A Wu ◽  
C Murphy ◽  
H G Callan ◽  
J G Gall
Keyword(s):  
Germinal Vesicle ◽  
Spherical Shape ◽  
Nucleic Acid Hybridization ◽  
Immunofluorescent Staining ◽  
U1 Snrna ◽  
Heterogeneous Nuclear Ribonucleoproteins ◽  
Specific Antigens ◽  
Nascent Transcripts ◽  
Relationship Of

We have examined the distribution of snRNPs in the germinal vesicle (GV) of frogs and salamanders by immunofluorescent staining and in situ nucleic acid hybridization. The major snRNAs involved in pre-mRNA splicing (U1, U2, U4, U5, and U6) occur together in nearly all loops of the lampbrush chromosomes, and in hundreds to thousands of small granules (1-4 microns diameter) suspended in the nucleoplasm. The loops and granules also contain several antigens that are regularly associated with snRNAs or spliceosomes (the Sm antigen, U1- and U2-specific antigens, and the splicing factor SC35). A second type of granule, often distinguishable by morphology, contains only U1 snRNA and associated antigens. We propose the term "snurposome" to describe the granules that contain snRNPs ("snurps"). Those that contain only U1 snRNA are A snurposomes, whereas those that contain all the splicing snRNAs are B snurposomes. GVs contain a third type of snRNP granule, which we call the C snurposome. C snurposomes range in size from less than 1 micron to giant structures greater than 20 microns in diameter. Usually, although not invariably, they have B snurposomes on their surface. They may also contain from one to hundreds of inclusions. Because of their remarkably spherical shape, C snurposomes with their associated B snurposomes have long been referred to as spheres or sphere organelles. Most spheres are free in the nucleoplasm, but a few are attached to chromosomes at specific chromosome loci, the sphere organizers (SOs). The relationship of sphere organelles to other snRNP-containing structures in the GV is obscure. We show by immunofluorescent staining that the lampbrush loops and B snurposomes also react with antibodies against heterogeneous nuclear ribonucleoproteins (hnRNPs). Transcription units on the loops are uniformly stained by anti-hnRNP and anti-snRNP antibodies, suggesting that nascent transcripts are associated with hnRNPs and snRNPs along their entire length, perhaps in the form of a unitary hnRNP/snRNP particle. That B snurposomes contain so many components involved in pre-mRNA packaging and processing suggests that they may serve as sites for assembly and storage of hnRNP/snRNP complexes destined for transport to the nascent transcripts on the lampbrush chromosome loops.

Tumor Microenvironment-Triggered In-Situ Cancer Vaccines with Dual Immunogenic Cell Death Inductions for Elevated Antitumor and Antimetastatic Therapy

Nanoscale ◽  
2021 ◽  
Author(s):  
Jun Lin ◽  
Binbin Ding ◽  
Pan Zheng ◽  
Dong Li ◽  
Meifang Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Microenvironment ◽  
Immune Responses ◽  
Cancer Immunotherapy ◽  
Cancer Vaccines ◽  
High Specificity ◽  
The Body ◽  
Immunogenic Cell Death ◽  
Specific Antigens

Cancer vaccine is to make tumor-specific antigens into vaccines, which then are injected back into the body to activate immune responses for cancer immunotherapy. Despite the high specificity and therapeutic...

Differentiation of allantoic endoderm implanted into the presumptive digestive area in avian embryos. A study with organ-specific antigens

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 137-153
Author(s):  
Sadao Yasugi
Keyword(s):  
Digestive Tract ◽  
Intestinal Epithelium ◽  
Digestive Organ ◽  
Chick Embryos ◽  
Avian Embryos ◽  
Digestive Organs ◽  
Organ Specific ◽  
Specific Antigens

Quail allantoic endoderm was implanted into the presumptive digestive-tract area of chick embryos, and the differentiation of the endoderm was examined morphologically and immunocytochemically with antisera against pepsinogens and sucrase. The allantoic endoderm was incorporated into the host digestive organs. It often became continuous with the host endoderm and formed a chimaeric digestive-tract epithelium. It differentiated morphologically into the epithelium of the digestive organ into which it was incorporated, showing the morphological inductive ability in situ of the digestive-tract mesenchyme against the allantoic endoderm. However, the allantoic endoderm did not produce pepsinogens even when it was incorporated into the host proventricular mesenchyme and formed well-developed proventricular glands. This result indicates that the heterotypic morphogenesis of the allantoic endoderm is not necessarily accompanied by the heterotypic cytodifferentiation. In contrast, the anti-sucrase antiserum-reactive cells often differentiated in the allantoic endoderm incorporated into not only the intestine but also other organs. This confirmed our previous observation that the allantoic endoderm has a tendency to differentiate into the intestinal epithelium in the heterologous environment.

scholarly journals Microstructure and mechanical properties of slowly cooled Cu47.5Zr47.5Al5

2007 ◽  
Vol 22 (2) ◽  
pp. 326-333 ◽  
Author(s):  
J. Das ◽  
S. Pauly ◽  
C. Duhamel ◽  
B.C. Wei ◽  
J. Eckert
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Volume Fraction ◽  
Spherical Shape ◽  
High Yield ◽  
High Yield Strength ◽  
Scanning Calorimetry ◽  
Arc Melting ◽  
Martensite Matrix

Cu47.5Zr47.5Al5 was prepared by arc melting and solidified in situ by suction casting into 2–5-mm-diameter rods under various cooling rates (200–2000 K/s). The microstructure was investigated along the length of the rods by electron microscopy, differential scanning calorimetry and mechanical properties were investigated under compression. The microstructure of differently prepared specimens consists of macroscopic spherical shape chemically inhomogeneous regions together with a low volume fraction of randomly distributed CuZr B2 phase embedded in a 2–7 nm size clustered “glassy-martensite” matrix. The as-cast specimens show high yield strength (1721 MPa), pronounced work-hardening behavior up to 2116 MPa and large fracture strain up to 12.1–15.1%. The fracture strain decreases with increasing casting diameter. The presence of chemical inhomogenities and nanoscale “glassy-martensite” features are beneficial for improving the inherent ductility of the metallic glass.

Relationship of corneal asphericity to intraocular lens power calculations after myopic laser in situ keratomileusis

2016 ◽  
Vol 42 (5) ◽  
pp. 703-709 ◽  
Author(s):  
Yosai Mori ◽  
Kimiya Shimizu ◽  
Keiichiro Minami ◽  
Kazutaka Kamiya ◽  
Nobuyuki Shoji ◽  
...  
Keyword(s):  
Intraocular Lens ◽  
Laser In Situ Keratomileusis ◽  
Power Calculations ◽  
Intraocular Lens Power ◽  
Corneal Asphericity ◽  
Lens Power ◽  
Relationship Of

scholarly journals OLA1 is responsible for normal spindle assembly and SAC activation in mouse oocytes

2019 ◽  
Author(s):  
Di Xie ◽  
Juan Zhang ◽  
JinLi Ding ◽  
Jing Yang ◽  
Yan Zhang
Keyword(s):  
Spindle Assembly Checkpoint ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Spindle Assembly ◽  
Mouse Oocyte ◽  
Immunofluorescent Staining ◽  
Germinal Vesicle Breakdown ◽  
Oocyte Meiosis ◽  
Polar Body Extrusion ◽  
Spread Analysis

Background. OLA1 is a member of the GTPase protein family, unlike other members, it can bind and hydrolyze ATP more efficiently than GTP. OLA1 participates in cell proliferation, oxidative response and tumorigenesis. However, whether OLA1 is also required for oocyte meiosis is still unknown. Methods. In this study, the localization, expression, and functions of OLA1 in the mouse oocyte meiosis were examined. Immunofluorescent and confocal microscopy were used to explore the location pattern of OLA1 in the mouse oocyte. Moreover, nocodazole treatment was used to confirm the spindle-like location of OLA1 during mouse meiosis. Western blot was used to explore the expression pattern of OLA1 in the mouse oocyte. Microinjection of siRNA was used to explore the OLA1 functions in the mouse oocyte meiosis. In addition, chromosome spreading was used to investigate the spindle assembly checkpoint (SAC) activity. Results. Immunofluorescent staining showed that OLA1 evenly distributed in the cytoplasm at germinal vesicle (GV) stage. After meiosis resumption (GVBD), OLA1 co-localized with spindles, which was further identified by nocodazole treatment experiments. Knockdown of OLA1 impaired the germinal vesicle breakdown progression and finally resulted in a lower polar body extrusion rate. Immunofluorescence analysis indicated that knockdown of OLA1 led to abnormal spindle assembly, which was evidenced by multipolar spindles in OLA1-RNAi-oocytes. After 6 h post-GVBD in culture, an increased proportion of oocyte which has precociously entered into anaphase/telephase I (A/TI) was observed in OLA1-knockdown oocytes, suggesting that loss of OLA1 resulted in the premature segregation of homologous chromosomes. In addition, the chromosome spread analysis suggested that OLA1 knockdown induced premature anaphase onset was due to the precocious inactivation of SAC. Taken together, we concluded that OLA1 plays important role in GVBD, spindle assembly and SAC activation maintenance in oocyte meiosis.

In situstudy of the kinetics of growth of Pb nanoparticles embedded in a PbO–B2O3glass

2018 ◽  
Vol 51 (2) ◽  
pp. 395-405
Author(s):  
Andreia Gorgeski ◽  
Aldo Felix Craievich ◽  
Leonardo Marcon Corrêa ◽  
Luciano Andrei Montoro ◽  
Guinther Kellermann
Keyword(s):  
Isothermal Annealing ◽  
Equilibrium Concentration ◽  
Spherical Shape ◽  
Distribution Functions ◽  
Relative Dispersion ◽  
Droplet Growth ◽  
Temperature Dependences ◽  
Different Temperatures ◽  
Size Dispersion

The process of growth of liquid Pb nanoparticles embedded in a lead borate glass was investigated by transmission electron microscopy (TEM) and byin situsmall-angle X-ray scattering (SAXS) during isothermal annealing at different temperatures within the 649–679 K range. A TEM study at room temperature of the glass–Pb nanoparticle composite, previously subjected to isothermal annealing, showed the presence of a number of nearly spherical Pb nanocrystals with some size dispersion. The analysis of several series of experimental SAXS curves recordedin situ, for increasing periods of time of isothermal annealing at different temperatures, allowed the authors to determine time and temperature dependences of the radius distribution functions of the growing spherical Pb nanoparticles. Since all selected annealing temperatures were higher than the melting temperature of bulk Pb, the Pb nanoparticles were in all cases in the liquid state during the whole growth process. A fast increase in the total volume of Pb droplets was observed during the initial stages of annealing, which indicated that the Pb droplets grow because of the incorporation of Pb atoms dispersed in the glass matrix. For more advanced stages of droplet growth, when the concentration of Pb atoms becomes close to its equilibrium concentration, the time dependences of the average radius, number density and total volume of Pb droplets are those predicted by the classical theory of coarsening proposed by Lifshitz–Slyosov–Wagner. Furthermore, it has been established that the Pb nanodroplets preserve their spherical shape and their relative dispersion in size through the whole coarsening process and that the activation energy for diffusion of Pb atoms and growth of Pb droplets embedded in the studied glass isEa= 2.65 ± 0.09 eV per atom.

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