DNA dependent RNA polymerase from Drosophila melanogaster embryonic cells from a cell line
Chatterjee, R.N.
Indian Journal of Experimental Biology 23(1): 1-7
1985
ISSN/ISBN: 0019-5189 PMID: 3926638 Document Number: 256745
DNA dependent RNA polymerase(s) from Echalier LK 213 embryonic cells line of D. melanogaster was/were isolated and purified to homogeneity. The enzyme(S) has/nave no preference for the homologous template. The 2 isolated forms of the enzyme complex were similar to analogous polymerases (A and B or I and II) of other eukaryotes in their enzymatic and structural properties and were stimulated by Mn2+. The optimum ionic strength could be considered as 1 of the invariant characteristics of the 2 enzymes. In particular, the RNA polymerase II was highly sensitive to low concentration of .alpha.-amanitin. In situ transcription by Drosophila RNA Polymerase II on D. hydei polytene nuclei reveal more or less localized template activity on the chromosomes. When Escherichia coli RNA polymerase (holoenzyme) was assayed on the fixed salivary gland chromosomes of the D. hydei, a considerable number of Ag grains were observed on both the nucleolus and chromosomes. The pattern of distribution of Ag grains on the chromosomes formed as a consequence of incorporation of 3H-RNA precursor upon the use of Drosophila RNA polymerase II did not show a strictly homologous pattern comparable to that produced by E. coli polymerase. Analysis of autoradiograms further reveals that transcription patterns under in situ were not strictly comparable with patterns obtained in vivo.