Size and distribution of polyadenylic acid sequences in Drosophila polytene DNA and RNA.
[3H]Poly(U) hybridizes very rapidly to polytene DNA from Drosophila hydei. When hybridization is performed at 30 degrees C in 2 X SSC to a large excess of DNA, 95% of the poly(U) becomes ribonuclease resistant. Also, complementary RNA transcribed in vitro from polytene DNA hybridizes to poly(U). 023--0.25% of the DNA is composed of (dA)-rich sequences and 0.23--0.31% of cRNA hybridizes to [3H]poly(U). The length of the (dA)-rich sequences on the DNA and cRNA is 40 nucleotides. The Tm values of these hybrids formed between DNA or cRNA-poly(U) is 45 degrees C. The poly(A) fragments from cytoplasmic RNA ranged from 80 to 170 nucleotides in lenght, and migrated in polyacrilamide gels as a broad peak. The average sizes of the poly(A) fragments from the poly(A)-containing RNA transcribed by nuclei isolated from salivary glands in vivo or in vitro were 40, 70, 170 and 70 nucleotides, respectively. Hybridization in situ of [3H]-poly(U) to chromosome squashes indicated that the (dA)-rich sequences are randomly distributed over the whole genome.
D000818:Animals; D004247:DNA / Q000378:metabolism*; D004330:Drosophila; D066298:In Vitro Techniques; D009693:Nucleic Acid Hybridization; D011061:Poly A / Q000032:analysis / Q000378:metabolism*; D011072:Poly U; D012313:RNA / Q000378:metabolism*; D012260:Ribonucleases
D011061:Poly A; D011072:Poly U; D012313:RNA; D004247:DNA; D012260:Ribonucleases