Asunto(s)
Complejo IV de Transporte de Electrones/genética , Genes , Isoenzimas/genética , Saccharomyces cerevisiae/enzimología , Secuencia de Aminoácidos , Núcleo Celular/metabolismo , ADN/genética , ADN Mitocondrial/genética , Complejo IV de Transporte de Electrones/metabolismo , Genes Fúngicos , Isoenzimas/metabolismo , Sustancias Macromoleculares , Mitocondrias/enzimología , Datos de Secuencia Molecular , Mutación , Saccharomyces cerevisiae/genéticaRESUMEN
We studied the diets of four sympatric carnivores in the flooding savannas of western Venezuela by analysing predator DNA and prey remains in faeces. DNA was isolated and a portion of the cytochrome b gene of the mitochondrial genome amplified and sequenced from 20 of 34 scats. Species were diagnosed by comparing the resulting sequences to reference sequences generated from the blood of puma (Puma concolor), jaguar (Panthera onca), ocelot (Leopardus pardalus) and crab-eating fox (Cerdocyon thous). Scat size has previously been used to identify predators, but DNA data show that puma and jaguar scats overlap in size, as do those of puma, ocelot and fox. Prey-content analysis suggests minimal prey partitioning between pumas and jaguars. In field testing this technique for large carnivores, two potential limitations emerged: locating intact faecal samples and recovering DNA sequences from samples obtained in the wet season. Nonetheless, this study illustrates the tremendous potential of DNA faecal studies. The presence of domestic dog (Canis familiaris) in one puma scat and of wild pig (Sus scrofa), set as bait, in one jaguar sample exemplifies the forensic possibilities of this noninvasive analysis. In addition to defining the dietary habits of similar size sympatric mammals, DNA identifications from faeces allow wildlife managers to detect the presence of endangered taxa and manage prey for their conservation.
Asunto(s)
Carnívoros/fisiología , Heces , Reacción en Cadena de la Polimerasa/métodos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Cartilla de ADN/genética , ADN Mitocondrial , Cadena Alimentaria , Mamíferos , Especificidad de la EspecieRESUMEN
D-myo-Inositol 1,4,5-trisphosphate has been previously demonstrated to act as a second messenger for the hormonal mobilization of intracellular calcium in rat liver. In this study, the breakdown of D-myo-inositol 1,4,5-trisphosphate by a phosphatase activity was characterized. Using partially purified subcellular fractions, it was found that D-myo-inositol 1,4,5-trisphosphate phosphatase (I-P3ase) specific activity was highest in the plasma membrane fraction, while D-myo-inositol 1,4-bisphosphate phosphatase specific activity was highest in the cytosolic and microsomal fractions. The plasma membrane I-P3ase was Mg2+-dependent with optimal activity observed at 0.5-1.5 mM free Mg2+. The enzyme had a neutral pH optimum, suggesting that it was neither an acid nor alkaline phosphatase. Neither LiCl nor NaF inhibited the I-P3ase activity. However, both L-cysteine and dithiothreitol stimulated the activity 2-fold. Spermine (2.0 mM) inhibited the I-P3ase activity by 50%, while putrescine and spermidine had little or no effect.