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Biomedical subjects

J Bonner

Publications and source records attributed to J Bonner.

At least 91 records · Page 5Linked to original sources
PubMed1974

Interspersion of repetitive and single-copy sequences in nuclear ribonucleic acid of high molecular weight.

Nuclear RNA of high molecular weight, approximately 15 to 30 x 10(3) nucleotides long, isolated from rat ascites cells, has been shown previously to contain both middle repetitive and single-copy sequences. However, it was not known whether these sequences were located on separate molecules or whether they were interspersed within the same molecule. The present communication distinguishes between these possibilities and shows that a large proportion of nuclear RNA of high molecular weight consists of interspersed middle repetitive and single-copy sequences.

Animals↗
PubMed1974

Partial purification of the template-active fraction of chromatin: a preliminary report.

A fraction of rat-liver chromatin that is transcriptionally active in vivo has been purified 6- to 7-fold over whole chromatin. This was accomplished by selectively shearing chromatin with DNase II followed by fractionating the released portion on the basis of its solubility properties in 2 mM MgCl(2). The resulting soluble material comprises 11% of the total chromatin DNA and is impoverished in histone and enriched in nonhistone protein. Compared with unsheared chromatin, this minor fraction exhibits marked differences in chromosomal protein species. DNA renaturation studies indicate that this fraction is composed of a specific subset of whole genomal DNA sequences. Furthermore, DNA.RNA hybridization experiments suggest that almost 60% of the nonrepetitious DNA sequences of this minor fraction could code for cellular RNA.

Animals↗
PubMed1973

A proposal for the structure of the Drosophila genome.

We propose a structure for the genome of Drosophila melanogaster in which each chromatid of each chromomere (band) consists on the average of about 30-35 different sequences of single-copy (unique) DNA, each on the average about 750 base pairs in length. These are separated from one another by stretches of the middle repetitive (reiterated) DNA, which in D. melanogaster makes up about 15% of the genome. These stretches are about 100-150 base pairs in length and are all of the same sequence or family in each individual chromomere and of a different family (sequence) in each different chromomere. Our proposed structure of the Drosophila genome is in accord with all of the known facts concerning the physical chemistry and molecular biology of Drosophila DNA.

Animals↗
PubMed1972

Chromosomal RNA: its properties.

We describe the properties of a special class of RNA associated with chromatin. We discuss why this RNA should be considered a distinct class of RNA and not an artifactual degradation product of either transfer or ribosomal RNA.

Acrylamides↗