1998 Volume 8 Issue 1 Pages 28-43
Trypanosoma evansi is morphologically indistinguishable from T. brucei. Close relationship between T. evansi and T. brucei was further documented by Gibson, Wilson and Moloo (1983), Masiga and Gibson (1990) and Stevens et al. (1992), suggesting that T. evansi is derived from T. brucei. However, T. evansi has been distinguished from T. brucei by their lack of maxicircle DNA, minicircle DNA homogeneity and lack of developmental stages in its insect vectors (Stuart 1983). Although several features of the minicircle DNA sequence have been reported to be specific for T. evansi (Masiga et al. 1990; Artama, Agey and Donelson 1992), we report here that two strains of T. brucei (T. b. gambiense Welcome and T. b. rhodesiense IL1501) also possess “the T. evansi specific” minicircle DNA sequence.
Furthermore, Artama et al. (1992) have reported a similarity of PCR amplification patterns of the procyclic acidic repetitive protein (PARP), which is known to be a major surface protein of procyclic forms of T. brucei (Mowatt and Clayton 1987; Richardson et al. 1988), between T. evansi and T. brucei. In this study, we confirmed the existence of the similarity and suggested the use of the PARP primer as a diagnostic tool for the T. evansi infection. Although the PCR detection using this primer will not still distinguish the T. evansi infection from the T. brucei infection, it will be specially useful outside of the tsetse belt in where both the kinetoplastic and akinetoplastic strains of T. evansi are widely prevalent but not T. brucei.
Moreover, the PARP A-α gene of T. evansi was sequenced, and the expression of the PARP gene in T. evansi was, for the first time, demonstrated by means of RT-PCR, although T. evansi is lacking the procyclic stage in its life cycle.
