Comparative microarray analysis of Rhipicephalus (Boophilus) microplus expression profiles of larvae pre-attachment and feeding adult female stages on Bos indicus and Bos taurus cattle.
BACKGROUND
Rhipicephalus (Boophilus) microplus is an obligate blood feeder which is host specific to cattle. Existing knowledge pertaining to the host or host breed effects on tick transcript expression profiles during the tick - host interaction is poor.


RESULTS
Global analysis of gene expression changes in whole R. microplus ticks during larval, pre-attachment and early adult stages feeding on Bos indicus and Bos taurus cattle were compared using gene expression microarray analysis. Among the 13,601 R. microplus transcripts from BmiGI Version 2 we identified 297 high and 17 low expressed transcripts that were significantly differentially expressed between R. microplus feeding on tick resistant cattle [Bos indicus (Brahman)] compared to R. microplus feeding on tick susceptible cattle [Bos taurus (Holstein-Friesian)] (p <or= 0.001). These include genes encoding enzymes involved in primary metabolism, and genes related to stress, defence, cell wall modification, cellular signaling, receptor, and cuticle formation. Microarrays were validated by qRT-PCR analysis of selected transcripts using three housekeeping genes as normalization controls.


CONCLUSIONS
The analysis of all tick stages under survey suggested a coordinated regulation of defence proteins, proteases and protease inhibitors to achieve successful attachment and survival of R. microplus on different host breeds, particularly Bos indicus cattle. R. microplus ticks demonstrate different transcript expression patterns when they encounter tick resistant and susceptible breeds of cattle. In this study we provide the first transcriptome evidence demonstrating the influence of tick resistant and susceptible cattle breeds on transcript expression patterns and the molecular physiology of ticks during host attachment and feeding.
Rodriguez-Valle
Manuel
M
Cooperative Research Centre for Beef Genetic Technologies, Armidale, NSW, Australia. manuel.rodriguezvalle@deedi.qld.gov.au
Lew-Tabor
Ala
A
Gondro
Cedric
C
Moolhuijzen
Paula
P
Vance
Megan
M
Guerrero
Felix D
FD
Bellgard
Matthew
M
Jorgensen
Wayne
W
D000821:Animal Feed; D000818:Animals; D002417:Cattle; D004198:Disease Susceptibility; D020224:Expressed Sequence Tags / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D023281:Genomics; D007113:Immunity, Innate; D007814:Larva / Q000235:genetics; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048494:Rhipicephalus / Q000235:genetics*