The fact that it is exclusively active during the day further suggests its eyesight should be strong, to aid in hunting and predator avoidance.
We have functionally analyzed a novel promoter region of the rodent parasite Plasmodium berghei that is exclusively active during the liver stage of the parasite.
In Arabidopsis, the At α-dox1 promoter is exclusively active in roots whereas the At α-dox2 promoter is exclusively active in shoots [ 19, 28, 34].
Of these, ~3,000 were exclusively active before differentiation, and ~5,000 were only active after differentiation (whereas the remaining enhancers were constitutively marked in both conditions).
In this context it is interesting to note that the lycophyte Selaginella moellendorffii possesses also only a single RpoT polymerase, which likely is exclusively active in mitochondria [ 26].
Since vincristine was the only tested drug that is exclusively active in metaphase, these results point to a cell cycle phase specificity of IGFBP7-induced drug resistance.
The gene is exclusively active in the mesophyll cells of leaves but inactive in the directly adjacent bundle sheath cells or in other tissues, such as roots [ 9].
However, the 5′ enhancer has been shown to be exclusively active in endothelial cells, thus allowing specific and permanent genetic labeling of endothelial cells and their progeny (Sinclair et al., 1999; Göthert et al., 2004).
Alternatively, kinesin-2 and dynein-1b motors may be exclusively active on anterograde and retrograde cargos, respectively, and pausing of anterograde trains could produce forces that oppose the gliding forces of paused retrograde trains.
We engineered a targeting vector to express the beta subunit of photo activated adenylyl cyclase from the soil bacterium Beggiatoa (bPAC) under the control of the protamine 1 promoter (Prm1, Figure 1A) that is exclusively active in post-meiotic spermatids (Zambrowicz et al., 1993).
