Conformation of proflavine-bound DNA molecules

Proflavine, DNA, Electron Microscopic Study The conformational changes suffered by full-length double-stranded DNA molecules from bac­ teriophage T7, due to their binding with the mutagenic dye proflavine (PF), has been studied by electron microscopy. The dye-bound DNA showed a smoother contour and a more compact con­ figuration in comparison with the dye-free native DNA. These changes resulted from the stretching, extension and charge-neutralization accompanying the incorporation of PF.

Skeletal polymorphism and genetic drift in a Delhi frog, Rana cyanophlictis

Nineteen axial skeletal variants are described in the frog Rana cyanophlictis, collected from five isolated populations of Delhi. Four of these populations came from large perennial ponds and one, a transitory population, was entrapped from a temporary rain pool. The populations were found to diverge significantly from each other in the incidence of these skeletal variants. We have attributed this divergence to genetic drift, but the effects of unknown selective forces cannot be ruled out.