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A Amos

Publications and source records attributed to A Amos.

47 records · Page 3Linked to original sources
PubMed1983

Measurement of DNA length by gel electrophoresis. I. Improved accuracy of mobility measurements using a digital microdensitometer and computer processing.

The electrophoretic mobilities of DNA polymer fragments in an agarose gel have been measured from a photograph of the gel by different methods and converted to lengths by the reciprocal method. The method of measurement can introduce large errors in the length estimates. The use of a digital microdensitometer to obtain optical density profiles of gel tracks with subsequent computer processing to find peak positions was found to give the most accurate DNA lengths.

Bacteriophage lambda↗
PubMed1981

The distribution of repetitive DNAs between regular and supernumerary chromosomes in species of Glossina (Tsetse): a two-step process in the origin of supernumeraries.

Several species of tsetse fly within the Morsitans and Fusca subgenera of Glossina contain supernumerary (B) chromosomes. Previous studies on the meiotic behaviour of chromosomes (Southern and Pell, 1973) and the C-band patterns (Jordan et al., 1977) have indicated a close similarity between the Y chromosome and the supernumeraries. The distributions of the highly abundant families of DNA (satellite DNAs) between the autosomes, sex chromosomes and B chromosomes of G.m. morsitans, G. austeni and G. pallidipes have been examined by in situ hybridisation. In addition, the organisation and sequence homologies of satellite DNAs have been examined by restriction enzymes and heterologous hybridisations in in situ and "Southern" transfer conditions. The majority of satellite sequences that are homologous between species are distributed in several different arrangements between A and B chromosome telomeres with minority sequences at some centromeric and intercalary locations. There is no extensive satellite DNA similarity between the Y and B chromosomes. We suggest that the Y and B chromosome associations and synchronous allocycly during meiosis are the result of extensive heterochromatinisation of these two chromosome types, that is probably a reflection of two separate stages involved in the generation of the B chromosomes in the genus. The independent evolution of satellites and supernumeraries is discussed.

Animals↗
PubMed1980

Interaction of DNA with cytosolic 3-methylcholanthrene binding proteins from either rat or mouse liver.

The ability of cytosolic 3-methylcholanthrene binding proteins from rat liver to interact with DNA was studied using DNA-cellulose chromatography. Two DNA binding fractions, eluting in 0.15 M KCl (peak 1) and 0.33 M KCl (peak 2), were observed on salt elution from a denatured DNA-cellulose column which had been incubated with rat liver cytosol containing radiolabelled 3-methylcholanthrene. No detectable DNA binding fractions were found when columns containing cellulose alone or native DNA-cellulose were used. Temperature activation of the cytosolic proteins containing 3-methylcholanthrene did not result in a significant difference in DNA binding characteristics when compared with a non-treated sample. The pretreatment of rats with Aroclor 1254 induced peak 1 3.7 fold over control values. An analysis of the proteins present in peaks 1 and 2 from control and induced rats was carried out using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Comparative DNA-cellulose chromatography of cytosolic liver proteins from a cytochrome P-448 inducible mouse strain (DBA/6J) and non-inducible mouse strain (DBA/2J) showed much higher levels of DNA binding by protein bound 3-methylcholanthrene from C57BL/6J hepatic cytosol.

Animals↗