title: Transcriptional analysis of the major antigenic protein 1 multigene family of Cowdria ruminantium.
abstract: The major antigenic protein 1 (MAP1) of the tick-borne rickettsial pathogen Cowdria ruminantium is encoded by a multigene family containing conserved and variable genes. The part of a locus containing the map1 multigene family that was characterized contained three homologous, but non-identical map1 genes, designated map1-2, map1-1, and map1. Reverse transcriptase-polymerase chain reaction was used to study the transcriptional activity of these genes in isolates of C. ruminantium grown in bovine endothelial cells, in two different tick cell lines, and in Amblyomma variegatum ticks. The map1 gene was always transcribed, whereas transcription of map1-2 was not detected under any of the tested conditions. The map1-1 gene transcript was detected in A. variegatum ticks, but was not found in virulent C. ruminantium Senegal grown in bovine endothelial cells at 30 or 37 degrees C. Interestingly, transcripts of map1-1 were also found in different passages of the in vitro attenuated Senegal isolate grown in bovine endothelial cells, as well as in the Gardel isolate grown in two tick cell lines. When transcribed, map1-1 was present on a polycistronic messenger together with map1.
authors.affiliation: Division of Bacteriology, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Box 80165, 3508 TD, Utrecht, The Netherlands.
authors.forename: Cornelis P J
authors.initials: CP
authors.lastname: Bekker
authors.forename: Lesley
authors.initials: L
authors.lastname: Bell-Sakyi
authors.forename: Edith A
authors.initials: EA
authors.lastname: Paxton
authors.forename: Dominique
authors.initials: D
authors.lastname: Martinez
authors.forename: Albert
authors.initials: A
authors.lastname: Bensaid
authors.forename: Frans
authors.initials: F
authors.lastname: Jongejan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002417:Cattle; D002460:Cell Line; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016995:Ehrlichia ruminantium / Q000235:genetics*; D004730:Endothelium, Vascular / Q000166:cytology / Q000382:microbiology; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013987:Ticks / Q000166:cytology / Q000382:microbiology; D014158:Transcription, Genetic
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D012329:RNA, Bacterial; C086402:major antigenic protein 1, Cowdria ruminantium