Figure 1. Representative example of the evolution of Le expression diversity of H. pylori strain J166 in animal A (E6C). Le^x and Le^y expression was determined in single colony-derived cell populations preinoculation (A), and at week 14 (B), and week 40 postinoculation (C). The preinoculation cells showed predominant Le^y expression. Fourteen weeks after inoculation, the cells recovered from the stomach of monkey E6C were mixed in their Le expression, including colonies (3, 5, 7, 8) with Le^x predominance. By 40 wk, 7 of 8 colonies sampled showed Le^x predominance, and the other colony showed low expression of both Le^x and Le^y. The differences between the preinoculation isolates (n=7) and the week 40 isolates (n=8) are highly significant for both Le^x (247±76 vs. 1771±797) and Le^y (2113±257 vs. 203±112) expression (P <0.001).