TRYPANOSOMA-CRUZI GENOME PROJECT - BIOLOGICAL CHARACTERISTICS AND MOLECULAR TYPING OF CLONE CL BRENER

Clone CL Brener is the reference organism used in the Trypanosoma cruz i Genome Project. CL Brener was obtained by cloning procedures from bl oodstream trypomastigotes isolated from mice infected with the CL stra in. The doubling time of CL Brener epimastigotes cultured at 28 degree s C in liver infusion-tryptose (LIT) medium is 58 +/- 13 h. Differenti ation to metacyclic forms is induced by incubation of epimastigotes in LIT-20% Grace's medium. Metacyclics give very low parasitemia in mice , contrary to what is observed for blood forms which promote 100% mort ality of the animals with inocula of 5 x 10(3) parasites. CL Brener bl ood forms are highly susceptible to nifurtimox, benznidazole and ketoc onazole. Allopurinol is inefficient in the treatment of mice experimen tal infection. The clone infects mammalian cultured cells and performs the complete intracellular cycle at 33 and 37 degrees C. The molecula r typing of CL Brener has been done by isoenzymatic profiles; sequenci ng of a 24S alpha ribosomal RNA gene domain and by schizodeme, randoml y amplified polymorphic DNA and DNA fingerprinting analyses. For each typing approach the patterns obtained do not change after prolonged pa rasite subcultivation in LIT medium (up to 100 generations). The stabi lity of the molecular karyotype of the clone was also confirmed. (C) 1 997 Elsevier Science B.V.