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1.
Phys Rev Lett ; 127(15): 156601, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34678000

RESUMEN

Magnetoresistance of the correlated narrow-gap semiconductor FeSi was investigated by the radio frequency self-resonant spiral coil technique in magnetic fields up to 500 T, which is supplied by an electromagnetic flux compression megagauss generator. Semiconductor-to-metal transition accomplishes around 270 T observed as a sharp kink in the magnetoresistance, which implies the closing of the hybridization gap by the Zeeman shift of band edges. In the temperature-magnetic field phase diagram, the semiconductor-metal transition field is found to be almost independent of temperature, which is in contrast to a characteristic magnetic field associated with the hopping magnetoconduction in the in-gap localized states, exhibiting a notable temperature dependence.

2.
Phys Rev Lett ; 122(22): 226601, 2019 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-31283289

RESUMEN

The Lifshitz transition, a change in Fermi surface topology, is likely to greatly influence exotic correlated phenomena in solids, such as high-temperature superconductivity and complex magnetism. However, since the observation of Fermi surfaces is generally difficult in the strongly correlated systems, a direct link between the Lifshitz transition and quantum phenomena has been elusive so far. Here, we report a marked impact of the pressure-induced Lifshitz transition on thermoelectric performance for SnSe, a promising thermoelectric material without a strong electron correlation. By applying pressure up to 1.6 GPa, we have observed a large enhancement of the thermoelectric power factor by more than 100% over a wide temperature range (10-300 K). Furthermore, the high carrier mobility enables the detection of quantum oscillations of resistivity, revealing the emergence of new Fermi pockets at ∼0.86 GPa. The observed thermoelectric properties linked to the multivalley band structure are quantitatively reproduced by first-principles calculations, providing novel insight into designing the SnSe-related materials for potential valleytronic as well as thermoelectric applications.

3.
Spinal Cord ; 54(9): 656-61, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26620877

RESUMEN

STUDY DESIGN: A cross-sectional study. OBJECTIVES: Neuropathic pain (NP) after spinal cord injury (SCI) tends to be hard to treat, and its heterogeneous properties make it difficult to identify and characterize. This study was conducted to assess the characteristics of SCI-related NP in detail. SETTING: A single hospital for SCI rehabilitation. METHODS: This study included 72 patients who were seen at our hospital in 2012 and 2013 and who had sustained SCI at least 3 months before enrollment. The patients completed the Neuropathic Pain Symptom Inventory (NPSI) and the Short Form (SF)-36 Health Inventory. The NPSI score was analyzed for correlations with clinical presentations of SCI and SF-36 subitems. RESULTS: Paresthesia/dysesthesia was the most common subtype of NP after SCI. With regard to location, below-level superficial NP was significantly more intense than at-level pain. Patients who underwent surgery showed significantly less evoked pain compared with patients with non-surgery. Patients reported significantly more severe pain if >1 year had elapsed after the SCI. Patients with an American Spinal Injury Association Impairment Scale grade of B for completeness of injury reported more intense NP than those with other grades. Among the SF-36 subitems, NP correlated significantly with bodily pain, general health and mental health. CONCLUSION: NP in SCI patients was significantly associated with the location of pain, the time period since the injury, surgery and quality-of-life factors. A more detailed understanding of the characteristics of NP may contribute to better strategies for relieving the pain associated with SCI.


Asunto(s)
Neuralgia/etiología , Calidad de Vida/psicología , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/psicología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Traumatismos de la Médula Espinal/cirugía , Estadística como Asunto , Estadísticas no Paramétricas
4.
Phys Rev Lett ; 114(22): 227202, 2015 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-26196641

RESUMEN

We have synthesized high-quality single crystals of volborthite, a seemingly distorted kagome antiferromagnet, and carried out high-field magnetization measurements up to 74 T and ^{51}V NMR measurements up to 30 T. An extremely wide 1/3 magnetization plateau appears above 28 T and continues over 74 T at 1.4 K, which has not been observed in previous studies using polycrystalline samples. NMR spectra reveal an incommensurate order (most likely a spin-density wave order) below 22 T and a simple spin structure in the plateau phase. Moreover, a novel intermediate phase is found between 23 and 26 T, where the magnetization varies linearly with magnetic field and the NMR spectra indicate an inhomogeneous distribution of the internal magnetic field. This sequence of phases in volborthite bears a striking similarity to those of frustrated spin chains with a ferromagnetic nearest-neighbor coupling J_{1} competing with an antiferromagnetic next-nearest-neighbor coupling J_{2}.

5.
J Cell Biol ; 135(6 Pt 2): 1741-7, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8991087

RESUMEN

Rabphilin-3A is a putative target protein for Rab3A, a member of the small GTP-binding protein superfamily that has been suggested to play a role in regulated exocytosis in presynapses. In this study we determined the expression and the function of Rabphilin-3A in mouse eggs at fertilization. Rabphilin-3A mRNA and protein were detected by reverse transcriptase-PCR and immunoblot analysis, respectively, in metaphase II mouse eggs. Immunofluorescence analysis showed that Rabphilin-3A protein was distributed in the cortical region in eggs. Sperm induces cortical granule (CG) exocytosis via an increase in cytosolic Ca2+ at fertilization. We microinjected the NH2- or COOH-terminal fragment of recombinant Rabphilin-3A into metaphase II eggs. Neither treatments altered the sperm-induced cytosolic Ca2+ increase, but both inhibited CG exocytosis in a dose-dependent manner. The NH2-terminal fragment was more effective than the COOH-terminal fragment. Full-length Rabphilin-3A did not affect CG exocytosis, but it attenuated the inhibition of CG exocytosis by the NH2-terminal fragment. These results show that Rabphilin-3A is involved in Ca(2+)-dependent CG exocytosis at fertilization in mouse eggs.


Asunto(s)
Gránulos Citoplasmáticos/fisiología , Exocitosis/fisiología , Proteínas de Unión al GTP/genética , Proteínas del Tejido Nervioso/genética , Óvulo/química , Proteínas de Unión al GTP rab , Proteínas Adaptadoras Transductoras de Señales , Animales , Calcio/metabolismo , Exocitosis/efectos de los fármacos , Femenino , Fertilización/fisiología , Proteínas de Unión al GTP/análisis , Expresión Génica/fisiología , Glutatión Transferasa/farmacología , Hemaglutininas/farmacología , Masculino , Metafase/fisiología , Ratones , Ratones Endogámicos , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/análisis , Óvulo/citología , Óvulo/fisiología , Fragmentos de Péptidos/farmacología , ARN Mensajero/metabolismo , Transducción de Señal/fisiología , Proteínas de Transporte Vesicular , Rabfilina-3A
6.
Science ; 189(4196): 53-5, 1975 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-806114

RESUMEN

Multicellular complexes of Blepharisma intermedium are regularly produced by treating doublet cells with the gamone of complementary mating type. Cells remain united without undergoing nuclear cycles of conjugation. However, if a cell of complementary mating type unites, nuclear cycles begin at the site of this union and propagate all through the multicellular complex.


Asunto(s)
Cilióforos/fisiología , Reproducción , Animales , División Celular , Núcleo Celular/fisiología , Células Cultivadas , Cilióforos/citología , Cilióforos/ultraestructura , Citoplasma/fisiología , Meiosis , Fenotipo
7.
Science ; 185(4151): 621-3, 1974 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-4210354

RESUMEN

Gamone 1 of Blepharisma intermedium was isolated, identified as a slightly basic glycoprotein (mizoleclular weight, 2 x 10(5)), and designated as blepharmnone. At the concentration of 6 x 10(-8) milligram per milliliter, it specifically transforms matinig type 2 cells, so that they can conjugate in about 2 hours.


Asunto(s)
Cilióforos/análisis , Conjugación Genética , Glicoproteínas/aislamiento & purificación , Bioensayo , Cromatografía por Intercambio Iónico , Cilióforos/efectos de los fármacos , Conjugación Genética/efectos de los fármacos , Electroforesis en Gel de Poliacrilamida , Glicoproteínas/farmacología , Focalización Isoeléctrica , Peso Molecular
8.
Science ; 179(4071): 400-2, 1973 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-17843768

RESUMEN

One of the gamones (gamone II) which are effective for the induction of conjugation in Blepharisma intermedium has been isolated in a crystalline form and designated as blepharismin. From the result of chemical and spectroscopic investigations, in which x-ray crystallographic analysis was used as a definitive tool, blepharismin has been found to have the structure of calcium 3-(2'-formylamino-5'-hydroxybenzoyl)lactate.

9.
Science ; 214(4521): 669-71, 1981 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-7027442

RESUMEN

Partially purified thymosin fraction 5 and one of its synthetic peptide components, thymosin beta 4, but not thymosin alpha 1, stimulated secretion of luteinizing hormone--releasing factor from superfused medial basal hypothalami from random cycling female rats. In addition, luteinizing hormone was released from pituitary glands superfused in sequence with hypothalami. No release of luteinizing hormone in response to thymosin was observed from pituitaries superfused alone. These data provide the first evidence of a direct effect of the endocrine thymus on the hypothalamus and suggest a potentially important role for thymic peptides in reproductive function.


Asunto(s)
Hormona Liberadora de Gonadotropina/metabolismo , Hipotálamo/efectos de los fármacos , Timosina/farmacología , Hormonas del Timo/farmacología , Animales , Hormonas/farmacología , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Ratas , Relación Estructura-Actividad
10.
Science ; 293(5533): 1327-30, 2001 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-11509734

RESUMEN

We characterized an activation mechanism of the human LTRPC2 protein, a member of the transient receptor potential family of ion channels, and demonstrated that LTRPC2 mediates Ca2+ influx into immunocytes. Intracellular pyrimidine nucleotides, adenosine 5'-diphosphoribose (ADPR), and nicotinamide adenine dinucleotide (NAD), directly activated LTRPC2, which functioned as a Ca2+-permeable nonselective cation channel and enabled Ca2+ influx into cells. This activation was suppressed by intracellular adenosine triphosphate. These results reveal that ADPR and NAD act as intracellular messengers and may have an important role in Ca2+ influx by activating LTRPC2 in immunocytes.


Asunto(s)
Antígenos CD , Canales de Calcio/metabolismo , Calcio/metabolismo , Eosinófilos/metabolismo , Canales Iónicos , Proteínas de la Membrana , Monocitos/metabolismo , Linfocitos T/metabolismo , ADP-Ribosil Ciclasa , ADP-Ribosil Ciclasa 1 , Adenosina Difosfato Ribosa/metabolismo , Adenosina Difosfato Ribosa/farmacología , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Antígenos de Diferenciación/metabolismo , Apoptosis , Línea Celular , Humanos , Células Jurkat , Glicoproteínas de Membrana , Potenciales de la Membrana , NAD/metabolismo , NAD/farmacología , NAD+ Nucleosidasa/metabolismo , Técnicas de Placa-Clamp , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Canales Catiónicos TRPM
11.
Clin Exp Dermatol ; 34(7): 830-3, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19438532

RESUMEN

An evaluation was made of a fully automated index of psoriasis, termed Computer-assisted Area and Severity Index (CASI). This method requires taking digital photographs of the target skin area(s) with a colour reference marker, Casmatch. The CASI evaluates the severity of the psoriasis from the size and redness of the lesion(s). In five patients with mild psoriasis vulgaris mainly observed on their trunk, 18 photographs of the trunk were taken every 2 weeks. Three of the five patients [Psoriasis Area and Severity Index (PASI) of 3.0, 3.6 and 10.1, respectively] were treated with oral cyclosporin 3 mg/kg/day for 4 weeks. The mean +/- SD area of lesion selected by a dermatologist was 2.3 +/- 1.3% of the total skin area. This method achieved extraction performance for psoriasis of 72.1 +/- 19.4% for sensitivity and 97.4 +/- 2.0% for specificity. CASI correlated strongly with PASI (r = 0.92), but not with Skindex16 (r = 0.35). Although only erythema was evaluated, our preliminary results indicate that this method is capable of quantifying psoriasis lesions.


Asunto(s)
Interpretación de Imagen Asistida por Computador/métodos , Psoriasis/patología , Índice de Severidad de la Enfermedad , Calibración , Color , Ciclosporina/uso terapéutico , Fármacos Dermatológicos/uso terapéutico , Humanos , Fotograbar/métodos , Psoriasis/tratamiento farmacológico , Sensibilidad y Especificidad
12.
Nat Commun ; 10(1): 1229, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30874548

RESUMEN

Geometrical frustration and a high magnetic field are two key factors for realizing unconventional quantum states in magnetic materials. Specifically, conventional magnetic order can potentially be destroyed by competing interactions and may be replaced by an exotic state that is characterized in terms of quasiparticles called magnons, the density and chemical potential of which are controlled by the magnetic field. Here we show that a synthetic copper mineral, Cd-kapellasite, which comprises a kagomé lattice consisting of corner-sharing triangles of spin-1/2 Cu2+ ions, exhibits an unprecedented series of fractional magnetization plateaus in ultrahigh magnetic fields of up to 160 T. We propose that these quantum states can be interpreted as crystallizations of emergent magnons localized on the hexagon of the kagomé lattice.

13.
Nat Commun ; 10(1): 1059, 2019 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-30837479

RESUMEN

Manipulating topological spin textures is a key for exploring unprecedented emergent electromagnetic phenomena. Whereas switching control of magnetic skyrmions, e.g., the transitions between a skyrmion-lattice phase and conventional magnetic orders, is intensively studied towards development of future memory device concepts, transitions among spin textures with different topological orders remain largely unexplored. Here we develop a series of chiral magnets MnSi1-xGex, serving as a platform for transitions among skyrmion- and hedgehog-lattice states. By neutron scattering, Lorentz transmission electron microscopy and high-field transport measurements, we observe three different topological spin textures with variation of the lattice constant controlled by Si/Ge substitution: two-dimensional skyrmion lattice in x = 0-0.25 and two distinct three-dimensional hedgehog lattices in x = 0.3-0.6 and x = 0.7-1. The emergence of various topological spin states in the chemical-pressure-controlled materials suggests a new route for direct manipulation of the spin-texture topology by facile mechanical methods.

14.
Nat Commun ; 9(1): 408, 2018 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-29379016

RESUMEN

Quantum states characterized by nontrivial topology produce interesting electrodynamics and versatile electronic functionalities. One source for such remarkable phenomena is emergent electromagnetic field, which is the outcome of interplay between topological spin structures with scalar spin chirality and conduction electrons. However, it has scarcely been exploited for emergent function related to heat-electricity conversion. Here we report an unusually enhanced thermopower by application of magnetic field in MnGe hosting topological spin textures. By considering all conceivable origins through quantitative investigations of electronic structures and properties, a possible origin of large magneto-thermopower is assigned to the strong energy dependence of charge-transport lifetime caused by unconventional carrier scattering via the dynamics of emergent magnetic field. Furthermore, high-magnetic-field measurements corroborate the presence of residual magnetic fluctuations even in the nominally ferromagnetic region, leading to a subsisting behavior of field-enhanced thermopower. The present finding may pave a way for thermoelectric function of topological magnets.

17.
Cancer Res ; 51(21): 5956-9, 1991 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-1933859

RESUMEN

We have elucidated the importance of a transforming growth factor (TGF) alpha and epidermal growth factor receptor autocrine mechanism on the growth of a human ovarian serous cystadenocarcinoma-derived cell line (SHIN-3) in vitro. In this study, we studied the biological significance of this autocrine mechanism in vivo using female athymic nude (nu/nu) mice. We measured the mouse plasma epidermal growth factor and TGF alpha levels by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Plasma epidermal growth factor concentrations were remarkably decreased by sialoadenectomy (Sx): 410 +/- 65 (SE) pg/ml (n = 10) in intact animals; and undetectable in Sx mice (n = 5). Plasma TGF alpha levels were 90 and 40 pg/ml in intact and in Sx animals, respectively. Ten million SHIN-3 cells inoculated into nu/nu mice formed tumors in 100% of mice, and tumors grew progressively. Implantabilities and tumor growth rates of inoculated cells were not affected by Sx and even by Sx and anti-mouse epidermal growth factor antibody treatment. However, anti-TGF alpha monoclonal antibody (mAb) administered to SHIN-3 cell-inoculated Sx animals drastically reduced the tumor growth. Although 10(7) SHIN-3 cells formed tumors in this group, tumor growth was significantly inhibited by 10 micrograms of anti-TGF alpha mAb given 3 times a week, and growth inhibitions were more by 20 micrograms of anti-TGF alpha mAb. Moreover, as aggressive tumor growth as that in Sx animals was resumed by the cessation of anti-TGF alpha mAb treatments. All these data suggested the biological importance of a TGF alpha/epidermal growth factor receptor autocrine mechanism on the growth of this cell line in vivo.


Asunto(s)
Cistoadenoma/patología , Receptores ErbB/fisiología , Neoplasias Ováricas/patología , Factor de Crecimiento Transformador alfa/fisiología , Animales , Anticuerpos Monoclonales/administración & dosificación , División Celular , Línea Celular , Cistoadenoma/fisiopatología , Ensayo de Inmunoadsorción Enzimática , Factor de Crecimiento Epidérmico/análisis , Femenino , Humanos , Cinética , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Neoplasias Ováricas/fisiopatología , Radioinmunoensayo , Factor de Crecimiento Transformador alfa/análisis , Factor de Crecimiento Transformador alfa/inmunología , Trasplante Heterólogo
18.
Cancer Res ; 51(21): 5951-5, 1991 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-1718591

RESUMEN

Although transforming growth factor (TGF) alpha and epidermal growth factor (EGF) receptor (EGFR) autocrine mechanism is widely demonstrated in many kinds of cancers, its biological significances still remain circumstantial. We critically assessed the significance of this mechanism on the growth of an ovarian cancer cell line. Northern blot analysis in polyadenylated RNA isolated from cells by using 32P-labeled pre-TGF alpha, EGRF, and prepro-EGF complementary DNAs as probes revealed that pre-TGF alpha and EGFR but not prepro-EGF gene transcripts were expressed in the cell. TGF alpha and EGFR but not EGF proteins were observed by immunocytochemical stainings, using monoclonal antibodies against human TGF alpha, EGFR, and EGF, respectively. This cell line possessed a class of high affinity EGF receptor by 125I-EGF binding studies; Kd being 2.9 x 10(-10) M and Bmax to be 7.7 x 10(4) sites/cell. As much as 1.12 +/- 0.14 ng (SD; n = 3)/10(7) cells/24 h of TGF alpha was secreted in the conditioned media. These results suggested the expression of a TGF alpha/EGFR autocrine mechanism in this cell line. We, therefore, assessed the biological significance of this mechanism on the growth of this cell line in serum-free monolayer cell cultures. Although 0.1, 1.0, and 10 nM concentrations of TGF alpha did not show significant growth promotion, monoclonal antibodies against TGF alpha and EGFR but not EGF significantly inhibited cell growth. All these data suggested the biological importance of a TGF alpha/EGFR autocrine mechanism on the growth of this cell line in vitro.


Asunto(s)
División Celular/fisiología , Receptores ErbB/fisiología , Factor de Crecimiento Transformador alfa/fisiología , Anticuerpos Monoclonales , Antígenos de Carbohidratos Asociados a Tumores/análisis , Biomarcadores de Tumor/análisis , Northern Blotting , División Celular/efectos de los fármacos , Línea Celular , Medio de Cultivo Libre de Suero , Cistoadenoma , Factor de Crecimiento Epidérmico/genética , Factor de Crecimiento Epidérmico/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Receptores ErbB/genética , Femenino , Humanos , Cinética , Neoplasias Ováricas , Poli A/genética , Poli A/aislamiento & purificación , Precursores de Proteínas/genética , ARN/genética , ARN/aislamiento & purificación , ARN Mensajero , Factor de Crecimiento Transformador alfa/genética , Factor de Crecimiento Transformador alfa/farmacología , Factor de Crecimiento Transformador beta/genética
19.
Cancer Res ; 51(19): 5322-8, 1991 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-1717146

RESUMEN

We examined 35 primary human ovarian adenocarcinomas for the presence of epidermal growth factor (EGF) receptor (EGFR) in plasma membranes from cancer tissues by using 125I-EGF as a ligand. Specific 125I-EGF bindings were observed in 20 (57%) of these 35 cases. Scatchard analysis showed a class of high affinity EGF receptor: Kd 5.0 +/- 1.0 x 10(-10) M; Bmax, 83.3 +/- 12.1 fmol/mg protein (mean +/- SE, n = 20). Northern analysis in polyadenylated RNA from 15 EGFR(+) cancers using pretransforming growth factor alpha (pre-TGF alpha), prepro-EGF complementary DNA, and pE7, a complementary DNA clone of human EGFR, as probes revealed that pre-TGF alpha and EGFR mRNAs but not prepro-EGF mRNA were expressed in all cases examined. Immunocytochemical studies using monoclonal antibodies (mAbs) against TGF alpha, EGF, and EGFR showed that TGF alpha and EGFR but not EGF proteins were present on ovarian cancer cells in all cases. These data suggested a possible TGF alpha/EGFR autocrine mechanism in EGFR(+) ovarian cancers. We, therefore, examined the biological significance of this autocrine mechanism by using primary monolayer cell cultures. In primary cultures from EGFR (+) cancers, TGF alpha added to the culture medium stimulated the [3H]thymidine incorporation dose dependently. Moreover, the addition of mAbs against TGF alpha and EGFR but not EGF inhibited [3H]thymidine incorporation dose dependently in EGFR(+) cancer cells. On the other hand, in primary cultures from EGFR(-) cancers, TGF alpha and anti-TGF alpha, -EGFR, and -EGF mAbs did not show any effects on [3H]thymidine incorporation. All these results suggested the possible crucial role of a TGF alpha/EGFR autocrine growth mechanism in primary human ovarian cancers which express EGFR.


Asunto(s)
Adenocarcinoma/metabolismo , Receptores ErbB/biosíntesis , Neoplasias Ováricas/metabolismo , Factor de Crecimiento Transformador alfa/biosíntesis , Northern Blotting , ADN/biosíntesis , Relación Dosis-Respuesta a Droga , Factor de Crecimiento Epidérmico/metabolismo , Femenino , Expresión Génica , Humanos , Neoplasias Ováricas/patología , ARN/análisis , Transcripción Genética , Células Tumorales Cultivadas
20.
Int J Dev Biol ; 45(4): 661-8, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11461002

RESUMEN

Isolation of cleavage-stage blastomeres and the study of their developmental potential has been used extensively for analyzing the mechanisms of embryogenesis in vertebrates, including amphibians and echinoderms. We devised a method to isolate 8-cell stage blastomeres in the teleost, shiro-uo, by utilizing its unique cleavage pattern of the horizontal 3rd cleavage plane. Removal of all the upper blastomeres at the 8-cell stage allowed almost normal embryogenesis from the remaining lower blastomeres and yolk cell mass. Isolated upper or lower blastomeres formed vesicles and spherical bodies, which later showed morphological changes during cultivation. Mesoderm formation was detected not only in the cultivated lower blastomeres or whole blastomeres but also in the upper blastomeres isolated from the yolk cell mass at the 8-cell stage, although at a lower frequency than the lower blastomeres. These results indicated the presence of very early signaling for mesoderm induction, which is independent from the currently postulated signals from the yolk syncytial layer at later stages. This also indicated non-equivalence or differentiation of the blastomeres from the very early cleavage stage in teleost embryos.


Asunto(s)
Blastocisto/fisiología , Mesodermo/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Células Cultivadas , ADN Complementario/metabolismo , Proteínas Fetales , Hibridación in Situ , Mesodermo/metabolismo , Modelos Biológicos , Datos de Secuencia Molecular , Perciformes , Reacción en Cadena de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Proteínas de Dominio T Box/genética , Factores de Tiempo , Xenopus , Proteínas de Pez Cebra/genética
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