Search results for "Vertebra"
showing 10 items of 1220 documents
Los mamíferos del Mioceno Inferior de la Cuenca de Ribesalbes-Alcora (Castelló, España)
2017
Objetivos El propósito principal de esta tesis es el estudio taxonómico, paleoecológico y bioestratigráfico de los mamíferos fósiles del Neógeno continental de Araia d’Alcora, en la Cuenca de Ribesalbes-Alcora (Castelló, España), a partir de la prospección de diversas secciones y del muestreo de los yacimientos de mayor interés. Los principales objetivos planteados en esta tesis han sido: • La obtención de un registro lo más completo posible de las faunas de mamíferos del área de estudio, mediante la identificación de niveles fosilíferos y la toma de muestras suficientemente grandes para obtener colecciones de fósiles representativas. • Determinación taxonómica de los grupos de mamíferos ha…
Preliminary palaeontological data from the Loma Negra section (Bardenas Reales de Navarra, Lower-Middle Miocene)
2013
En este trabajo se da a conocer una nueva localidad fosilífera de la Formación Tudela (Navarra). Esta formación está compuesta por facies palustres, lacustres y aluviales distales, que representan el relleno del sector occidental- central de la Cuenca del Ebro durante el Rambliense y el Aragoniense (Mioceno inferior-medio). Basado en el estudio de los restos fósiles de micromamíferos, la nueva localidad fosilífera se sitúa bioestratigráficamente en la zona D del Aragoniense. Los datos paleoecológicos obtenidos de los micromamíferos indican que el ambiente debió ser húmedo y la temperatura templada. En lo que respecta a la zona palustre, los ostrácodos, carofitas y gasterópodos definirían un…
Influence of Temperature, Hypercapnia, and Development on the Relative Expression of Different Hemocyanin Isoforms in the Common CuttlefishSepia offi…
2012
The cuttlefish Sepia officinalis expresses several hemocyanin isoforms with potentially different pH optima, indicating their reliance on efficient pH regulation in the blood. Ongoing ocean warming and acidification could influence the oxygen-binding properties of respiratory pigments in ectothermic marine invertebrates. This study examined whether S. officinalis differentially expresses individual hemocyanin isoforms to maintain optimal oxygen transport during development and acclimation to elevated seawater pCO2 and temperature. Using quantitative PCR, we measured relative mRNA expression levels of three different hemocyanin isoforms in several ontogenetic stages (embryos, hatchlings, juv…
Rhodopsin's carboxy-terminal cytoplasmic tail acts as a membrane receptor for cytoplasmic dynein by binding to the dynein light chain Tctex-1.
1999
AbstractThe interaction of cytoplasmic dynein with its cargoes is thought to be indirectly mediated by dynactin, a complex that binds to the dynein intermediate chain. However, the roles of other dynein subunits in cargo binding have been unknown. Here we demonstrate that dynein translocates rhodopsin-bearing vesicles along microtubules. This interaction occurs directly between the C-terminal cytoplasmic tail of rhodopsin and Tctex-1, a dynein light chain. C-terminal rhodopsin mutations responsible for retinitis pigmentosa inhibit this interaction. Our results point to an alternative docking mechanism for cytoplasmic dynein, provide novel insights into the role of motor proteins in the pola…
Cytotoxic activity of Ciona intestinalis (Tunicata) hemocytes: Properties of the in vitro reaction against erythrocyte targets
1993
Hemocytes (effectors) of Ciona intestinalis showed a natural cytotoxic capacity (HCA) when assayed in vitro against erythrocytes (targets). Cytotoxic cells lysed, to a variable extent, rabbit (RE), human (A, B, O), guinea pig, and sheep (SE) erythrocytes. Hemocyte cytotoxic activity (HCA) assayed against SE is a calcium-dependent reaction, occurs rapidly (15-30 min), at 25-37 degrees C over a wide range of pH (5.4-8.0). Assays were carried out using: 1) the medium in which hemocytes were maintained, 2) the soluble portion of hemocyte lysates, and 3) debris prepared from hemocyte lysates. Results suggest that HCA is a cell-mediated process that requires effector-target cell contacts. Anti-SE…
Vip3C, a novel class of vegetative insectidal proteins from Bacillus thuringiensis
2012
Three vip3 genes were identified in two Bacillus thuringiensis Spanish collections. Sequence analysis revealed a novel Vip3 protein class (Vip3C). Preliminary bioassays of larvae from 10 different lepidopteran species indicated that Vip3Ca3 caused more than 70% mortality in four species after 10 days at 4 οg/cm 2. © 2012, American Society for Microbiology.
Spirochaeta coccoides sp. nov., a novel coccoid spirochete from the hindgut of the termite Neotermes castaneus.
2006
ABSTRACT A novel spirochete strain, SPN1, was isolated from the hindgut contents of the termite Neotermes castaneus . The highest similarities (about 90%) of the strain SPN1 16S rRNA gene sequence are with spirochetes belonging to the genus Spirochaeta , and thus, the isolate could not be assigned to the so-called termite clusters of the treponemes or to a known species of the genus Spirochaeta . Therefore, it represents a novel species, which was named Spirochaeta coccoides . In contrast to all other known validly described spirochete species, strain SPN1 shows a coccoid morphology and is immotile. The isolated strain is obligately anaerobic and ferments different mono-, di-, and oligosacc…
Molecular characterization of the leucine cluster in Buchnera PSY, primary endosymbiont of the aphid Pemphigus spyrothecae
2002
ABSTRACT Buchnera strains from most aphid subfamilies studied to date have been found to carry the leucine gene cluster ( leuA , - B , - C , and - D ) on a plasmid, an organization unique among bacteria. Here, however, we demonstrate a classical chromosomal location of the cluster in Buchnera sp. strain PSY from the aphid Pemphigus spyrothecae (subfamily Pemphiginae). The genes that flank leuABCD in Buchnera sp. strain PSY appear to be adjacent in the genome of Buchnera sp. strain APS, a strain carrying a leucine plasmid. We propose that the presence of a leucine plasmid predates the diversification of symbiotic Buchnera and that the chromosomal location observed in Buchnera sp. strain PSY …
Identification and Expression of the SOS Response, aidB-Like, Gene in the Marine Sponge Geodia cydonium: Implication for the Phylogenetic Relationshi…
1998
Sponges (Porifera) are the phylogenetically oldest metazoan organisms. From one member of the siliceous sponges, Geodia cydonium, the cDNA encoding a putative SOS protein, the AidB-like protein of the Ada system from bacteria, was isolated and characterized. The cDNA, GCaidB, comprises an open reading frame of 446 amino acid (aa) residues encoding a polypeptide with a calculated Mr of 49,335. This molecule shows high similarity to the bacterial AidB proteins from Mycobacterium tuberculosis and Escherichia coli and somewhat lower similarities to acyl-CoA dehydrogenases (ADHs) and acyl-CoA oxidases (AOXs). Northern blot analysis confirmed the presence of the complete transcript. The deduced s…
Manipulating mtDNA in vivo reprograms metabolism via novel response mechanisms.
2019
Mitochondria have been increasingly recognized as a central regulatory nexus for multiple metabolic pathways, in addition to ATP production via oxidative phosphorylation (OXPHOS). Here we show that inducing mitochondrial DNA (mtDNA) stress in Drosophila using a mitochondrially-targeted Type I restriction endonuclease (mtEcoBI) results in unexpected metabolic reprogramming in adult flies, distinct from effects on OXPHOS. Carbohydrate utilization was repressed, with catabolism shifted towards lipid oxidation, accompanied by elevated serine synthesis. Cleavage and translocation, the two modes of mtEcoBI action, repressed carbohydrate rmetabolism via two different mechanisms. DNA cleavage activ…