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S C Roy

Publications and source records attributed to S C Roy.

At least 19 recordsLinked to original sources
PubMed1977

Orientation of interphase chromosomes as detected by Giemsa C-bands.

The orientation of Giemsa C-bands has been studied in mitotic and interphase cells of Allium cepa. A sativum and of Aloe vera. The C-bands in these three species are located at the telomeres, secondary constriction region of the nucleolar chromosomes and the centromeric regions, respectively. Observations in A. cepa and Aloe indicate clearly that the interphase chromosomes are non-random in their orientation and possibly maintain their telophase configuration through the attachment of telomeres and perhaps of kinetochores with the nuclear membrane. Electron micrographs of onion cells also reveal that certain heterochromatic segments are associated with the nuclear membrane.--The nucleolar interstitial C-bands in A. sativum remain free in the nucleoplasm and may come close to each other due to heterochromatic attraction. Such a heterochromatic attraction is also evident between telomeric regions and between centromeres. However, a two by two attachment could not be noticed. A diagrammatic representation of the orientation of interphase chromosomes has been presented.

Azure Stains↗
PubMed1977

Orientation of Giemsa C-bands in interphase cells of Allium cepa L.

Orientation of Giemsa C-bands in Allium cepa was studied in both mitotic and interphase cells. It has been shown that telophase orientation of the chromosome is maintained throughout the interphase and early phophase. It has been assumed that this non-random orientation is due to anchorage of the telomeres with the nuclear membrane. Contrary to earlier observations, 2 by 2 pairing of the telomers could not be traced to this species.

Chromosomes↗
PubMed1975

An inducible riboflavin synthetase from a pseudomonad.

Riboflavin synthetase activity is induced in a strain of Pseudomonas fluorescens-putida intermediate only under conditions permitting an accumulation of compound P, a 2,4-dioxopteridine, in the medium. The effect of different amino acids and sugars on the production of compound P and riboflavin synthetase was determined. The enzyme was partially destroyed by ammonium sulphate fractionation. It is inhibited by heavy metal ions and PCMB. PCMB inhibition can be almost completely reversed by GSH.

Amino Acids↗
PubMed1973

Protein synthesis in vitro in a system from plant mitochondria.

A mitochondrial system from 48h-germinating seeds of Vigna sinensis (Linn.) Savi is capable of incorporating l-[U-(14)C]valine into proteins and is practically insensitve to cycloheximide, but highly sensitive to chloramphenicol and fusidic acid, a potent inhibitor of peptide-chain elongation factor. A system consisting of mitochondrial S-100 fraction and ribosomes from the same source and other cofactors is capable of polyphenylalanine synthesis and behaves similarly with respect to these inhibitors.

Carbon Radioisotopes↗