Molecular cloning and genetic polymorphism of Babesia capreoli gene Bcp37/41, an ortholog of Babesia divergens merozoite surface antigen Bd37.
Babesia divergens and Babesia capreoli are closely related species with distinct host ranges, a zoonotic feature being described only for B. divergens. The two species are 99.8% similar in the 18S rDNA gene sequence and indistinguishable by morphological or serological means, leading to confusion as to their species status. The phylogenetic relatedness between the two species, and the frequent involvement of surface components in serological cross-reactions led us to postulate that an ortholog of Bd37, the merozoite surface antigen described for B. divergens, could also exist in B. capreoli. We were able to amplify a single partial PCR product from B. capreoli genomic DNA using primers specific for the B. divergens merozoite surface protein coding gene Bd37, and sequencing confirmed the presence of a Bd37 ortholog in B. capreoli, named Bcp37/41. The full sequences of the Bcp37/41 genes and their intron-exon structures were obtained for two cloned lines of B. capreoli. They suggest functional homologies between Bd37 and Bcp37/41 such as their surface localization, their role in immune escape mechanism and in the initial non-specific attachment to the erythrocyte. Restriction fragment length polymorphism (RFLP) analysis of the amplicons and partial sequencing revealed an extreme polymorphism within B. capreoli, greater than the one observed for its ortholog Bd37. Such a marker could thus be useful in epidemiological as well as phylogenetic studies.
INRA, UMR1300, F-44307 Nantes, France.
Yi
Y
Sun
Maggy
M
Jouglin
Suzanne
S
Bastian
Alain
A
Chauvin
Laurence
L
Malandrin
D000595:Amino Acid Sequence; D000953:Antigens, Protozoan / Q000235:genetics / Q000378:metabolism*; D001403:Babesia / Q000145:classification / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000235:genetics; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*
D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D015800:Protozoan Proteins