RESUMEN

Two kinds of small extrachromosomal nucleic acid elements were found in the bovine babesias, Babesia bovis and B. bigemina. One element with an apparent size of 5.5 kilobase pairs (kbp) is a double stranded RNA related to virus like particles. Another molecule is a double stranded DNA with a molecular size of about 6.2 kbp. Southern blot comparison of restriction DNA fragments of the latter molecule, which is present in both B. bovis and B. bigemina is described.

Asunto(s)

Babesia/genética , ADN/genética , Herencia Extracromosómica , ARN Bicatenario/genética , Animales , Babesia bovis/genética , ADN Protozoario/genética , Virus ARN , Homología de Secuencia de Ácido Nucleico , Especificidad de la Especie

RESUMEN

Babesia bovis is an intraerythrocytic protozoan that causes bovine babesiosis. Agarose gel electrophoresis of nucleic acids extracted from two isolates of B. bovis reveals, besides bulk DNA, an ethidium bromide-stainable band at about 5.5 kb. Further characterization of the latter with DNase I, RNase and mung bean nuclease suggested it to be a double-stranded RNA. Sonicated parasites were fractionated in a CsCl buoyant density gradient. A sample containing the 5.5-kb RNA was analysed under an electron microscope and a virus-like particle was observed.

Asunto(s)

Babesia/microbiología , ARN Viral/análisis , Animales , Babesia/genética , Babesiosis/genética , Bovinos , Centrifugación por Gradiente de Densidad , Desoxirribonucleasa I , ARN Bicatenario/análisis , Ribonucleasa Pancreática