Differential transcription of the major antigenic protein 1 multigene family of Ehrlichia ruminantium in Amblyomma variegatum ticks

• Published in: Veterinary microbiology 2007-06, Vol.122 (3), p.298-305
• Main Authors: Postigo, M., Taoufik, A., Bell-Sakyi, L., de Vries, E., Morrison, W.I., Jongejan, F.
• Format: Article
• Language: English
• Subjects: Amblyomma; Amblyomma variegatum; animal diseases; Animals; Antigens, Bacterial - genetics; bacterial antigens; Bacterial Outer Membrane Proteins - genetics; bacterial proteins; Bacteriology; Base Sequence; biochemical mechanisms; Biological and medical sciences; Cells, Cultured; DNA Primers; DNA, Bacterial - isolation & purification; Ehrlichia ruminantium; Ehrlichia ruminantium - genetics; Female; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Bacterial; heartwater; Heartwater Disease - transmission; host-pathogen relationships; in vivo studies; Ixodidae; life cycle (organisms); map 1 gene; MAP1; microbial genetics; Microbiology; midgut; Miscellaneous; Molecular Sequence Data; Multigene families; Multigene Family; outer membrane proteins; pathogenesis; reverse transcriptase polymerase chain reaction; Reverse Transcriptase Polymerase Chain Reaction - veterinary; RNA, Bacterial - isolation & purification; Ruminantia; salivary glands; Salivary Glands - microbiology; Sheep; Sheep Diseases - transmission; tick-borne diseases; ticks; Ticks - microbiology; transcription (genetics); Transcription, Genetic
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2007.01.019

The rickettsial pathogen Ehrlichia ruminantium causes heartwater in ruminants and is transmitted by ticks of the genus Amblyomma. The map1 gene, encoding the major surface protein MAP1, is a member of a multigene family containing 16 paralogs. In order to investigate differential transcription of genes of the map1 multigene family in vivo in unfed and feeding ticks, RNA was extracted from midguts and salivary glands of E. ruminantium-infected adult female Amblyomma variegatum ticks and analysed by RT-PCR using MAP1 paralog-specific primers. In unfed ticks, only transcripts from the map1-1 gene were observed in midguts and no transcripts were detected in salivary glands. In feeding ticks, map1-1 transcripts were more abundant in midguts whereas high levels of map1 transcripts were observed in salivary glands. Our results show that differential transcription of genes of the E. ruminantium map1 cluster occurs in vivo in different tissues of infected ticks before and during transmission feeding, indicating that this multigene family may be involved in functions of biological relevance in different stages of the life cycle of E. ruminantium.