RESUMEN
We report a molecular epidemiological study of rabies virus (RABV) strains circulating in animal populations in Bhutan, and investigate potential origins of these viruses. Twenty-three RABV isolates originating from dogs and other domestic animals were characterized by sequencing the partial nucleoprotein (N) gene (395 bp). Phylogenetic analysis was conducted and the Bhutanese isolates were compared with rabies viruses originating from other parts of the world. Phylogenetic analysis showed that Bhutanese isolates were highly similar and were closely related to Indian strains and South Asian Arctic-like-1 viruses. Our study suggests that the rabies viruses spreading in southern parts of Bhutan have originated from a common ancestor, perhaps from the Indian virus strain.
Asunto(s)
Enfermedades de los Bovinos/epidemiología , Enfermedades de los Perros/epidemiología , Virus de la Rabia/clasificación , Virus de la Rabia/aislamiento & purificación , Rabia/veterinaria , Enfermedades de los Porcinos/epidemiología , Animales , Bután/epidemiología , Bovinos , Enfermedades de los Bovinos/virología , Análisis por Conglomerados , Enfermedades de los Perros/virología , Perros , Genotipo , Epidemiología Molecular , Datos de Secuencia Molecular , Proteínas de la Nucleocápside/genética , Filogenia , Rabia/epidemiología , Rabia/virología , Virus de la Rabia/genética , Análisis de Secuencia de ADN , Porcinos , Enfermedades de los Porcinos/virologíaRESUMEN
Glutathione-S-transferases (GSTs) from chloroquine-resistant (CQR, K1) and -sensitive (CQS, T9/94) strains of Plasmodiumfalciparum were studied. The enzymes from both strains exhibited the optimal pH for enzyme catalysis, at pH 7.5, and were stable at temperatures below 60 degrees C. They also showed the highest specific activities toward CDNB and moderate activities to ethacrynic acid (40% of the activity to CDNB) but little or no activity for other substrates. Km and Vmax values for CDNB and GSH, calculated by Lineweaver-Burk plot from both CQR- and CQS-GSTs, were not statistically different (p<0.05). However, the GSTs activity from CQR appeared to be significantly higher than that from CQS. Therefore, we proposed that GSTs from both malarial strains are identical in their functional domain but different in level of gene expression. Furthermore, protein sequence alignment between P. falciparum GST and GSTs from other organisms suggested that the malarial enzyme is closely similar to other GSTs in Sigma, Alpha, Mu and Pi subclasses, probably most to the Alpha group. Characterization of the purified malarial GST in detail would reveal more precise classification and better understanding of its role in malarial detoxification.
Asunto(s)
Antimaláricos/farmacología , Cloroquina/farmacología , Resistencia a Medicamentos/genética , Glutatión Transferasa/biosíntesis , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/enzimología , Animales , Antimaláricos/metabolismo , Cloroquina/metabolismo , Glutatión Transferasa/metabolismo , Isoenzimas/biosíntesis , Isoenzimas/metabolismo , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/parasitología , Pruebas de Sensibilidad ParasitariaRESUMEN
Comparative ITS2 sequencing in the plant genus Aeschynanthus(Gesneriaceae) reveals an insertion/deletion (indel) hot spot in the ITS2 sequences that is difficult to align. Examination of other Gesneriaceae sequences shows that this is a widespread phenomenon in this plant family. Minimum free-energy secondary structure analyses localize the hot spot to the terminal part of arm 1. Arm 1 is twice as long in Gesneriaceae than in other asterids. In addition, the pattern of indels is consistent with this secondary structure model. The high variability of the extended terminal part of arm 1 in Gesneriaceae and the fact that it can be deleted altogether imply that it is functionally superfluous. In contrast, the base of arm 1 is relatively conserved and may function as an exonuclease recognition site. This study illustrates how comparative secondary structure analyses can be helpful in fine-scale alignment. Alignment based on secondary structure conflicts with our initial manual alignment and, to a lesser extent, with a CLUSTAL X alignment with default parameters.
Asunto(s)
ADN Espaciador Ribosómico/genética , ADN Ribosómico/genética , Evolución Molecular , Plantas/genética , Secuencia de Bases , Núcleo Celular/genética , ADN de Plantas/química , ADN de Plantas/genética , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , ARN Ribosómico/química , ARN Ribosómico/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido NucleicoRESUMEN
Aeschynanthus (Gesneriaceae) is a large genus of tropical epiphytes that is widely distributed from the Himalayas and China throughout South-East Asia to New Guinea and the Solomon Islands. Polymerase chain reaction (PCR) consensus sequences of the internal transcribed spacers (ITS) of Aeschynanthus nuclear ribosomal DNA showed sequence polymorphism that was difficult to interpret. Cloning individual sequences from the PCR product generated a phylogenetic tree of 23 Aeschynanthus species (two clones per species). The intraindividual clone pairs varied from 0 to 5.01%. We suggest that the high intraindividual sequence variation results from low molecular drive in the ITS of Aeschynanthus. However, this study shows that, despite the variation found within some individuals, it is still possible to use these data to reconstruct phylogenetic relationships of the species, suggesting that clone variation, although persistent, does not pre-date the divergence of Aeschynanthus species. The Aeschynanthus analysis revealed two major clades with different but overlapping geographic distributions and reflected classification based on morphology (particularly seed hair type).