[Duplication in the region of the phoA and lacZ genes on the Escherichia coli K-12 chromosome].

Transduction of genetic markers phoA1::Tn5 and lacZ::Tn10 was used to show the high frequency of occurrence of duplication (5-8%) carrying the above mentioned genes without application of selection for the increase of their function. Genetic tests were used to show that duplicated segments vary in size and in some cases comprise the whole lacZ-phoA region of Escherichia coli K-12 chromosome.

[Reiterated genes scattered among the chromosomes of Drosophila melangoaster with varying locations. V. Nature of self-complementary RNA sequences transcribed from chromosomal DNA].

Double-stranded RNA (dsRNA) sequences were isolated from either total RNA or cytoplasmic poly(A)+RNA of Drosophila melanogaster culture cells. Virtually all dsRNA was found to be of high molecular weight (> 200 base pairs) and unable to snap back after RNA melting. Thus, it corresponds to one of dsRNA classes found in mouse cells, namely, to dsRNA-A.