Anales de biología Vol. 5 (1985) Biología general, 1
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- PublicationOpen AccessMetabolismo de AIA-14C por secciones de plántulas de altramuz: influencia de diversos factores(Universidad de Murcia, Servicio de Publicaciones, 1985) Sánchez Bravo, José; Montalbán, A.; Acosta Echevarría, Manuel; Sabater, F.; Facultad de BiologíaThe auxinic metabolism in etiolated hypocotyls of Lupine is studied by incubation of sections in solutions of lAA-14C,. The prnduct:s are sequentially extracted with 95•/r ethanoL water and I M NaOH. Thé radiactivity in each fraction depends on different factors such as: time of incubation. hormone concentration. order of use of the solvents. permanence of auxin in the tissue and localization of the section in the hypocotyls. This suggests that conjugation or degradatíon of auxin can be affected and so the suspected equilibrium between the ditferent forms of auxins is altered.
- PublicationOpen AccessDeterminación fluorimétrica de ácido indolil-3-acético en altramuz(Universidad de Murcia, Servicio de Publicaciones, 1985) Sánchez Bravo, José; Ortuño Tomás, Ana María; Acosta Echevarría, Manuel; Sabater, F.; Facultad de BiologíaThe quantification of the phytohormone, indolil-3-acetic acid l]AAJ. in me.thanolic extracts of etiolated hypocotyls of Lupíne by a fluorimetric method, has been investigated. The applícation of the established criteria for the use of thís method shows that the observed fluorescence corresponds to the fluorescent lAA derivative. and that the other components of the methanolic extracts do not interfere in the measure. So, it is possible to quantify directly the !AA in the methanolic extracts without previous purification.
- PublicationOpen AccessCaracterización de la inulinasa e invertasa en Candida utilis(Universidad de Murcia, Servicio de Publicaciones, 1985) Argüelles Ordóñez, Juan Carlos; Gacto Fernández, Mariano José; Ros Espín, Rosa María; Facultad de Biologíalnvertase (E.C. 3.2.1.26) and inulinase (E.C. 3.2.1. 7) were analyzed in Candida utilis CECT 1061 to determine whether one single enzyme with both activities or two enzymes with different substrate specificities were present in this yeast. The synthesis of both fructofuranosidase activities was under control of catabolite repression by glucose and they were present in whole cell extracts as well as in the extracellular culture fluids. The cell-associated activities appear mostly located in the periplasmic space. The two activities exhíbited an identical optimum pH and similar profiles of thermal denaturation. In addition, a constan! ratio was found between the inulinase and the invertase activities in a variety of culture condítions when extracellular media or cell extracts were assayed. From the results obtained it was concluded that both activities reside in a same protein of molecular weight close to 450,000 dalton which shows a different affiníty for sucrose and inuline, Km values were 14 and 0,62mM. respectively.
- PublicationOpen AccessMolecular virology.:Reseña blbliográfica(Universidad de Murcia, Servicio de Publicaciones, 1985) Gacto Fernández, Mariano José; Vicente Soler, Jerónima; Facultad de Biología
- PublicationOpen AccessParámetros hematológicos de Rana perezi (Amphibia: Salientia)(Universidad de Murcia, Servicio de Publicaciones, 1985) Martínez López, Francisco Javier; Mendiola López, Pilar; Costa Ruiz, Jorge de; Facultad de BiologíaAs part of a wider research on respiratory properties of Rana perezi blood, the hematological parameters of this species have been measured. The study of blood O ,-transporting proteins (hemoglobin, Hb) and plasmatic proteins has also been initiated. Using fifteen females weighting 235 g (15.3-31.8), !he following results have been obtaíned: hematocrit (He(): 25. 7 :+:3.2 (ne, 15): Red blood cell count (RBC): 482:+: f 54x 1()3/mm1 (n=I4); Hb concentration: 5. 19:+:0.99 g/100 mi (n=9); mean corpuscYlar volume (MCV): 533.29 μ3; mean corpuscular Hb concentration (MCHC): 20.15% and mean corpuscular Hb (MCH): 107.5 pg. The electrophoresis of the Hb in 5% polyacrylamide gels showed two bands. Their quantification gave 72.38:+: ±20.19% (n=ll) for the anodic band and 27.62:t20.19 (n=ll) for the catodic one. Electrophoresis of plasma was performed in different kinds of polyacrylamide gels. the best obtained being in 7.5 and 8.5% gel. Electrophoretic behavíour of plasma proteins seems to be similar to that described in terrestrial vertebrates. These results are discussed and compared with data from other species belonging to Bufo. Hy/a and Rana genera.
- PublicationOpen AccessPapel de la Trehalasa en la levaduraschizosaccharomyces pombe: distribución durante el ciclo de desarrollo, caracterización y localización(Universidad de Murcia, Servicio de Publicaciones, 1985) Vicente Soler, Jerónima; Argüelles Ordóñez, Juan Carlos; Gacto Fernández, Mariano José; Facultad de BiologíaVegetative ceUs of Schizosaccharomyces pombe lack trehaiase activity but the enzyme activity is present at the ascospore stage and later disappears during germination. Cells of a yeast strain unable to sporulate are devoid of trehalase throughout the entire life cycle. The ascospore enzyme is not released to the culture medium and shows the properties of a nonregulatory trehaiase with acidic optimum pH and Km = 10'9x10-'M. On the basis of itsinvivo sensitivity to mild acid treatments and of its behaviour duringfractionation at low speed centrifugation of whole ascospore extracts, the enzyme appears to be externally located on the cells and covalently bound to the cell wall structure. In sifu inactivation of the trehalase enzyme partially blocks the initial morphological changes of germination. Germination of trehalase-less ascospores is further delayed when resynthesis of the enzyme is prevented by addition of cycloheximide. The results suggest that the trehalase enzyme plays a critica1 role in the early events of germination by mobilizing the endogenous trehalose stored in ascospores so that the process can take place even in the absence of externa1 carbon sources directly available provided other nutrients be present. Thus. the trehalose-trehalase system might represent in this yeast a significant mechanism that would allow to initiate germination under conditions in which the energy and carbon supplies in the surrounding medium are poor for the ascospores but could be used for the resulting vegetative cells.
- PublicationOpen AccessRespiración endócena de Ceriporla bresadolae (bdot. et galz.) bond. & sing. (Aphyllophorales: Basidiomycotina)(Universidad de Murcia, Servicio de Publicaciones, 1985) Martínez González, M. C.; Honrubia García, Mario; Facultad de BiologíaMeasures of Q02 have been made with Ceriporia bresadolae at different stages of growth and different temperatures. Values of respiratíon have been measured with suspensions of mycelium from C. bresadolae to which dífferent substrates such as piruvate, glucose, acetate and maltose were added exogenously. Strong activity has been obtained with piruvate and maltose. The respiratory quotient value was found to be 0.72.
- PublicationOpen AccessInterferón: mecanismos bioquímicos de formación y acción(Universidad de Murcia, Servicio de Publicaciones, 1985) Galindo Cascales, Jesús David; Solano Muñoz, Francisco; Iborra Pastor, José Luis; Facultad de BiologíaThe group of proteins known as interferons is now one of the most important fields of research in Biology. This review summarizes our present knowledge about the biochemical mechanisms of synthesis and action of interferons. Discovered by Isaacs and Lindenmann as agents of vira1 interference, today it is known that they are produced by most of vertebrates in response to a lot of appropiate stimuli. Here we discuss the ckssification of interferons, the human genes in which the information for their production and for the protein machinery involved in their response is contained, the biochemical mechanisms of the interferon production in ceUs treated by an inductor, and those developed in the surrounding cells when interferon is secreted. We conclude with the expression of therapeutic use of interferon and the existente of similar proteins in vegetal species.
- PublicationOpen AccessVariación de fase en Myxoccocus santhus: efecto de agentes mutagénicos(Universidad de Murcia, Servicio de Publicaciones, 1985) Elías Arnanz, Montserrat; Facultad de BiologíaThis paper includes quantitative data on a phase vanation phenomenon in the bactenum Myxococcus xanrhus which affects colonial pigmentation. The spontaneous or mutagen induced frequencies of phase vana- tion, both in wild type and colour mutant strains, can be explained by assuming that phase variation in M. xanrhus is geneticaily controlled and is also sensitive to physiological circumstances. The mutagen nitrosoguanidine induces a transitory unstability of the cellular phase, whereas UV light has not any effect on phase vanation.
- PublicationOpen AccessDegradación de celulosa y lignina en cultivo líquido de Ceriporia bresadolae (Bdot. et Galz.) Bond. & Sing. (Aphyllophorales: Basidiom ycotina)(Universidad de Murcia, Servicio de Publicaciones, 1985) Martínez González, M. C.; Honrubia García, Mario; Facultad de BiologíaThe celulose and lignin degradation potential of Cenpona bresadolae, a fungus causing brown rot in Pinus halepensis, has been measured as a percentage of weight loss of commercial celulose and lignin. It has been found that the degradation of celulose is dependent on the previous treatment of the substratum with chemical reagents. Besides, the presence of a carbohydrates such glucose. added exogenously, is necessary.