Date of Award
Doctor of Philosophy
Nuclei from Drosophila melanogaster embryos contain two major nonhistone chromosomal proteins which are extracted by 0.35 M NaCl and by 2% perchloric acid. A63 (M(,r) about 63,000) and A13 (M(,r) about 10,000) both contain high levels of basic and acidic amino acids, a property characteristic of high mobility group (HMG) proteins isolated from vertebrate tissues. Polytene chromosomes were stained by immunofluorescent techniques with anti-A13 polyclonal antibodies. The staining pattern indicates that A13 does not specifically react with puffs, nor is the protein preferentially associated with heterochromatin or nucleoli;There appears to be multiple binding sites for A13 throughout nuclei. A13 is rapidly released from nuclei by micrococcal nuclease. A13 cannot be completely released from nuclei by this nuclease, however, since even at very high digestion levels, the protein is also detected associated with nucleosomal fractions. At these high digestion levels, only histone Hl-depleted mononucleosomes are solubilized in 5 mM EDTA. Some of these mononucleosomes also contain A13. The results indicate that A13 closely resembles the properties possessed by vertebrate HMGs 1 and 2.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
James Andrew Bassuk
Bassuk, James Andrew, "Chromosomal distribution of Drosophila HMG-like proteins " (1983). Retrospective Theses and Dissertations. 8452.