Segmental Variation in a Duplicated msp2Pseudogene Generates Anaplasma marginaleAntigenic Variants

Anaplasma marginaleis a prototypical highly antigenically variant bacterial pathogen dependent on the sequential generation of major surface protein 2 (Msp2) outer membrane variants to establish persistent infection. Msp2 is encoded by a single expression site, and diversity is achieved by gene conversion of chromosomally encoded msp2pseudogenes.