Regulation of ribosomal RNA gene multiplicity in Drosophila melanogaster.

The synthesis of 5S RNA and its relationship to 18S and 28S ribosomal RNA in the bobbed mutants of Drosophila melanogaster.

Ribosomes contain one molecule each of 5S, 18S and 28S RNA. In Drosophila melanogaster although the genes for 18S + 28S are physically separated from the 5S RNA genes, the multiplicity of various ribosomal RNA genes is roughly the same. Thus a coordinate synthesis of these three molecules might seem feasible. This problem has been approached by determining the molar ratios of various RNA's in o...

Genetic analysis of the 5S RNA genes in Drosophila melanogaster.

The 5S RNA genes of Drosophila melanogaster in either an isogenic wildtype or a multiply inverted (SM1) chromosome 2 increase their multiplicity when opposite a deficiency for the 5S gene site. This is analogous to the compensation phenomenon previously described for the 18S and 28S ribosomal RNA genes of the X chromosome nucleolus organizer region. Molecular hybridization of 5S RNA to DNA cont...

Regulation of ribosomal RNA synthesis of Drosophila melanogaster

Regulation of ribosomal RNA and 5s RNA synthesis in Drosophila melanogaster. I. Bobbed mutants.

Analysis of the rates and amounts of rRNA and 5s RNA synthesized in Drosophila melanogaster bobbed mutants was done by using acrylamide-gel electrophoresis. The results show that the amounts of rRNA synthesized are constant, although the rates of rRNA synthesis in bb's are reduced to 30% of the wild-type level. The rates of synthesis of 5s RNA were constant. The rate of synthesis of the two kin...

Reciprocal recombination and the evolution of the ribosomal gene family of Drosophila melanogaster.

The role of reciprocal recombination in the coevolution of the ribosomal RNA gene family on the X and Y chromosomes of Drosophila melanogaster was assessed by determining the frequency and nature of such exchange. In order to detect exchange events within the ribosomal RNA gene family, both flanking markers and restriction fragment length polymorphisms within the tandemly repeated gene family w...