the antagonistic effects of rhizobium spp. isolates against rhizoctonia solani (ag-4), the causal agent of bean damping-off were compared with each other in either of the in vitro and in vivo conditions. also their potential to produce such secondary antifungal metabolites as hcn, siderophore and protease were evaluated. the results indicated that, isolate rh3 reduced mycelial growth of r. sola...

The ommatidia that constitute the compound eyes of flies contain eight photoreceptor cells, which are divided into two classes: the peripheral photoreceptors, R1-6, and the central photoreceptors, R7 and R8. In the fruit fly, Drosophila, R1-6 express the same rhodopsin (Rh1), whilst the R7 and R8 of a given ommatidium express either Rh3 and Rh5, or Rh4 and Rh6, respectively. We have studied whe...

PURPOSE To take advantage of specialized microscopic methods and transgenic stocks, to understand the properties of each rhodopsin now that Drosophila's six rhodopsins (Rh1-Rh6) have been isolated. METHODS The visual pigment containing organelles, the rhabdomeres, were imaged in live flies with the pseudopupil in standard and confocal microscopes. Five transgenic Drosophila strains in which R...

Opsin gene expression in the R7 and R8 photoreceptor cells of the Drosophila compound eye is highly coordinated. We have found that the R8 cell specific Rh5 and Rh6 opsins are expressed in non-overlapping sets of R8 cells, in a precise pairwise fashion with Rh3 and Rh4 in the R7 cells of individual ommatidia. Removal of the R7 cells in sevenless, boss or sina mutants, disrupts Rh5 expression an...

The compound eye of Drosophila melanogaster is composed of about 800 ommatidial units, each containing eight photoreceptor cells (R1–R8). Based on their spectral sensitivities, three subtypes can be distinguished [1]: The ‘pale’ (p) and ‘yellow’ (y) ommatidia [2] are distributed randomly throughout the main part of the eye (Figure 1A). They show different spectral sensitivity, at shorter and lo...

Comparison between the inputs of photoreceptors with different spectral sensitivities is required for color vision. In Drosophila, this is achieved in each ommatidium by the inner photoreceptors R7 and R8. Two classes of ommatidia are distributed stochastically in the retina: 30% contain UV-Rh3 in R7 and blue-Rh5 in R8, while the remaining 70% contain UV-Rh4 in R7 and green-Rh6 in R8. We show h...