Figure 1.

A. Schematic representation of the Pvcs gene, which consists of a conserved region (blank box) flanking a repeated region (grey box) which is itself flanked by pre- and post-repeat specific sequences (cross-hatched boxes). The bold horizontal line represents the PCR-amplified fragment used for further analysis. B. Example of the fragments (denoted A to G) of distinct size observed in different isolates, as single or as mixed infections (some lanes were not labelled because of lack of space). C. Fragments digested (D) or undigested (U) with Alu I or BstN I, two restriction enzymes with multiples sites in VK 210 type or VK247 type repeat sequences, respectively. Digestion cuts the fragment in small fragments of less than 150 bp in size. D. PCR-RFLP using specific restriction enzymes analysis for the presence/absence (yes/no) of specific pre- and post-repeat sequences in fragments carrying the VK210 or VK247 type repeats. Undigested fragments are denoted by (U) and P^r and P^o denote digests to determine the presence of pre- and post-repeat sequence types, respectively. A 100 bp ladder, where the 600 bp band stains most intensely, was used a molecular weight marker (M) for all the gels.