As expected all 4 genes were expressed in tick salivary glands and significantly induced upon feeding.
It is interesting to note that while Tat proteins are not synthesized during HL-60 cell infection [ 37], tatA is expressed in tick salivary glands, suggesting that A. phagocytophilum may utilize the Tat pathway during tick infection [ 58].
To identify proteins that interact with subolesin in yeast two-hybrid experiments, we used a cDNA library obtained from tick eggs because subolesin is expressed in tick embryos and gene knockdown affects egg development [ 8, 12].
Another arthropod borne pathogen Borrellia burgdorferi also regulates genes involved in pathogenesis in response to temperature shifts, including the surface protein OspC, which is expressed in mammals, and OspA, which is expressed in ticks [26], [28].
It is possible that the genes analyzed here could be expressed in multiple tick organs besides the SG and MG.
The tr promoter is one of the few characterized in Anaplasma and we have demonstrated it to be expressed in bacteria grown in both mammalian and tick cells.
bba64 has been shown to be expressed in culture during stationary phase, during infection of the mammalian host, and within the tick after 72 hours of tick feeding; however, bba64 is not expressed in flat (unfed) and 24 hour post-drop off replete ticks [15], [19], [27], [30], [31], [32].
Even if the scope of this technique should turn out to be more restricted in ticks than in Drosophila, our results suggest that a number of important genes being expressed in the tick synganglia can be targeted this way.
Expression analysis by RT-PCR showed that RAS-1 to -4 are expressed in other tick organs in addition to salivary glands and midguts.
Expression analysis by RT PCR showed that both HLSG-1 and -2 are expressed in other tick organs in addition to salivary glands and midguts.
