FIG. 4.

(A) In vitro inhibition using antiserum against Mo7 or R1A rMSA-1. B. bovis strain Mo7 merozoites were exposed to the indicated control (cont) or anti-rMSA-1 immune bovine or murine serum in vitro and incubated with bovine erythrocytes as described in Materials and Methods. The data show the mean ± standard deviation of the percentage of infected erythrocytes in three independent assays. ∗, P < 0.02; ∗∗, P < 0.001. (B) Cross-reactivity of immune sera against Mo7 and R1A rMSA-1. Murine anti-Mo7 rMSA-1 or murine anti-R1A rMSA-1 serum was reacted in immunoblots with URBC (n-RBC) or erythrocytes infected with the Mo7 or R1A strain of B. bovis. The position of the 45-kDa R1A MSA-1 molecule is indicated on the right and left.