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Biomedical subjects

D C Wallace

Publications and source records attributed to D C Wallace.

At least 235 records · Page 13Linked to original sources
PubMed1974

Cytoplasmic inheritance of chloramphenicol resistance in mouse tissue culture cells.

A chloramphenicol-resistant mutant, isolated from mouse A9 cells, was enucleated and fused with a nucleated chloramphenicol-sensitive mouse cell line. Resultant fusion products, cytoplasmic hybrids (or "cybrids"), were selected as resistant to chloramphenicol, and had the nuclear markers and chromosome complement of the chloramphenicol-sensitive parent. These cybrids appeared at the high frequency of 2-8 per 10(4) cells plated. Neither parent produced any colonies when plated under identical selective conditions. Fusion between enucleated chloramphenicol-sensitive cell fragments and the chloramphenicol-sensitive cell produced no resistant colonies, suggesting that chloramphenicol resistance is not due to an increase in the ratio of cytoplasm to nucleus. Furthermore, fusions between resistant and sensitive nucleated cells produced resistant hybrids at a frequency 100 times less than that of resistant cybrids. Thus, these stable chloramphenicol-resistant cybrids result from the fusion of a chloramphenicol-resistant cytoplasm with a chloramphenicol-sensitive cell. It is proposed, therefore, that chloramphenicol resistance is a cytoplasmically inherited characteristic in this mouse cell line.

Animals↗
PubMed1972

Evidence of genetic heterogeneity in Huntington's chorea.

In an extensive study of Huntington's chorea in Queensland evidence was found to support an old observation that the magnitude of the variation in the symptom complex of the disease between different families is sufficient to suggest that there may be more than one form of Huntington's chorea allele present in the community. Analysis of data concerning age at onset indicates that at least two separate forms of the disorder may exist.

Adolescent↗