RESUMEN
Squids of the family Ommastrephidae are distributed worldwide, and the family includes many species of commercial importance. To investigate phylogenetic relationships among squid species of the family Ommastrephidae, partial nucleotide sequences of two mitochondrial gene loci (cytochrome c oxidase subunit I [1277bp] and 16S rRNA [443bp]) of 15 ommastrephid species and two outgroup species from the families Loliginidae and Enoploteuthidae were determined and used to construct parsimony and distance based phylogenetic trees. The molecular data provided several new phylogenetic inferences. The monophyletic status of three subfamilies (Illicinae, Todarodinae and Ommastrephinae) was well supported, although phylogenetic relationships between the subfamilies were not resolved. Inclusion of a problematic species, Ornithoteuthis volatilis, to Todarodinae was indicated. Within Todarodinae, the Japanese common squid Todarodes pacificus was observed to have much closer relationship to the species of the genus Nototodarus than to its congener (Todarodes filippovae). These results indicate that re-evaluation of several morphological key characters for ommastrephid taxonomy may be necessary.
Asunto(s)
Cefalópodos/genética , ADN Mitocondrial/genética , Filogenia , Animales , Secuencia de Bases , Cartilla de ADN/genética , Complejo IV de Transporte de Electrones/genética , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN/veterinaria , Especificidad de la EspecieRESUMEN
In order to improve lead-barium exchangeability of barium hydroxyapatite (BaHAp), the effects of the recycle employment of BaHAp and the introduction of HCl into the exchange solution have been investigated at 293 K. The ion exchange capacity of BaHAp was evidently improved by use of the recycle experiments to reach levels approximately twice that obtained via the batch experiment. XPS analyses revealed that the ion exchange appears to proceed from the surface to the bulk of the apatite. The addition of HCl to the exchange solution also resulted in the enhancement of the ion exchangeability of BaHAp. Based on the apparent solubility of BaHAp, which was estimated from the dissolution of BaHAp for 4 h, together with the results of that experiment, it is suggested that the dissolution-precipitation mechanism appears to be possible for ion exchange. Copyright 2001 Academic Press.
RESUMEN
Proliferation and alpha(v)beta(3) integrin-dependent migration of vascular smooth muscle cells are suppressed on polymerized type I collagen. To identify genes specifically regulated in human smooth muscle cells by polymerized collagen, we used the suppressive subtraction hybridization technique. Compared with smooth muscle cells cultured on monomer collagen, polymerized collagen suppresses the following: (1) a number of other extracellular matrix proteins, including fibronectin, thrombospondin-1, tenascin-C, and cysteine-rich protein 61; (2) actin binding proteins including alpha-actinin; (3) signaling molecules; (4) protein synthesis-associated proteins; and (5) genes with unknown functions. Some of the identified genes, including cysteine-rich protein 61, show unique kinetics of mRNA regulation by monomer or polymerized collagen distinct from growth factors, suggesting extracellular matrix-specific gene modulation. Moreover, in vivo balloon catheter-mediated injury to the rat carotid artery induces many of the genes that are suppressed by polymerized collagen. Protein levels of thrombospondin-1 and fibronectin are also suppressed by polymerized collagen. Thrombospondin-1-mediated smooth muscle cell migration on vitronectin is significantly inhibited after culture on polymerized collagen for 24 hours, which is associated with decreased alpha-actinin accumulation at focal adhesions. Thus, polymerized type I collagen dynamically regulates gene expression, pericellular accumulation of extracellular matrix molecules, and the response to a given matrix molecule.
Asunto(s)
Colágeno/farmacología , Proteínas de la Matriz Extracelular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Actinina/efectos de los fármacos , Actinina/metabolismo , Animales , Northern Blotting , Arterias Carótidas/efectos de los fármacos , Arterias Carótidas/metabolismo , Arterias Carótidas/patología , Traumatismos de las Arterias Carótidas/etiología , Traumatismos de las Arterias Carótidas/genética , Cateterismo , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Quimiotaxis/efectos de los fármacos , Colágeno/química , ADN Complementario/genética , Modelos Animales de Enfermedad , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Sustancias de Crecimiento/farmacología , Humanos , Integrinas/fisiología , Cinética , Masculino , Microscopía Confocal , Músculo Liso Vascular/citología , Músculo Liso Vascular/metabolismo , Hibridación de Ácido Nucleico/métodos , Polímeros , ARN Mensajero/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Trombospondina 1/genética , Trombospondina 1/metabolismo , Trombospondina 1/farmacología , Vitronectina/farmacologíaRESUMEN
1. Young goldfish, Carassius auratus, were fed a calcium-deficient diet for 8 or 56 days and then their net uptake of calcium from the aquatic environment was examined using 45Ca. 2. They showed normal growth and the normal level of plasma calcium in both experiments. 3. In the short-term experiment, no dietary effect was found in the uptake of environmental calcium. In the long-term experiment, however, the rate of uptake was significantly stimulated by 18%. 4. The results indicate the presence of a compensatory action in calcium uptake between dietary and aquatic sources.