title: Expression of Babesia equi EMA-1 and EMA-2 during merozoite developmental stages in erythrocyte and their interaction with erythrocytic membrane skeleton.
abstract: In the present study, we investigated the cellular localizations and expression patterns of equi merozoite antigens (EMA) -1 and -2 of Babesia equi during its asexual erythrocytic-developmental cycle using anti-EMA-1t or -2t mono-specific mouse serum. Indirect fluorescent antibody tests demonstrated that EMA-1 and EMA-2 were not expressed in all the erythrocytic-developmental stages of the merozoites and that these two antigens were co-expressed during the early developmental stages. Additionally, it was shown that EMA-1 and EMA-2 were mutually expressed on the surface of extra-erythrocytic merozoites and also that the intra-erythrocytic merozoites shed only EMA-2 antigen in the infected erythrocytic cytoplasm or inside the membrane surface. The specific binding of EMA-2 to a Triton X-100-insoluble horse erythrocyte membrane fraction was also demonstrated. These findings facilitate our understanding of the biological roles of merozoite surface proteins of B. equi and our investigation for new drug targets.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kumar
authors.forename: Naoaki
authors.initials: N
authors.lastname: Yokoyama
authors.forename: Jung-Yeon
authors.initials: JY
authors.lastname: Kim
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Huang
authors.forename: Noboru
authors.initials: N
authors.lastname: Inoue
authors.forename: Xuenan
authors.initials: X
authors.lastname: Xuan
authors.forename: Ikuo
authors.initials: I
authors.lastname: Igarashi
authors.forename: Chihiro
authors.initials: C
authors.lastname: Sugimoto
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000378:metabolism; D000953:Antigens, Protozoan / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D001403:Babesia / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000469:parasitology*; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D017125:Genes, Protozoan / Q000235:genetics / Q000502:physiology; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D018613:Microscopy, Confocal; D015800:Protozoan Proteins / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C085964:EMA-1 protein, Babesia equi; C111468:EMA-2 protein, Babesia equi; D008565:Membrane Proteins; D015800:Protozoan Proteins