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Biomedical subjects

T Tokunaga

Publications and source records attributed to T Tokunaga.

At least 325 records · Page 18Linked to original sources

Transplantable sarcomas induced by 3-methylcholanthrene in inbred guinea pigs of JY-1 and Hartley/F strains.

Inbred strains of guinea pigs, JY-1 and Hartley/F, established in this Institute, were injected subcutaneously with 3-methylcholanthrene. During 1972 to 1974, 15 solid tumors (7 fibrosarcomas, 6 liposarcomas, and 2 atheroma-like tumors) have been induced in 12 animals out of 30 employed. Among the 15 tumors, 1 fibrosarcoma induced in JY-1 and 2 liposarcomas and 1 fibrosarcoma induced in Hartley/F were transplantable and established as the syngeneic lines named J4, H10, H12, and H9A, respectively. In addition, a transplant of J4 into the Hartley/F strain animal was established as an allogeneic subline and named JH4. Pathological and biological characteristics of these tumors are described and differences between these tumors and line 10 hepatoma, established by Rapp et al. in strain-2 guinea pig, are discussed.

Animals↗

Genetic recombination in mycobacteria.

Evidence for genetic recombination between Mycobacterium smegmatis strain Rabinowitchi (Rab) and strain Jucho or PM5 is presented. Backcrosses of recombinants by either parental strain indicated four different types of mating behavior, suggesting that the mycobacterial compatibilities are controlled by at least two different factors. No sex factor that transfers at a high frequency or that is sensitive to acridine dyes was detected. Analysis of segregation of unselected markers revealed that strain Jucho, or PM5, contributes the majority of alleles in almost all recombinants obtained from different selective media. Efforts to construct linkage maps for the markers employed failed because of ordering ambiguities. Mating medium containing streptomycin prevented genetic recombination when strain Rab was resistant to the antibiotic and Jucho, or PM5, was sensitive, but it did not prevent recombination when Rab was sensitive to streptomycin and Jucho, or PM5, was resistant. Very low frequency of recombinant formation was observed when Jucho, or PM5, had been treated with streptomycin, whereas recombinants were formed at fairly high frequencies when Rab had been treated with the antibiotic, suggesting that the roles of parental strains in zygote formation were not identical. The results suggest a polar transfer of genetic material from Rab to Jucho, or PM5, although an alternative possibility of cell fusion followed by exclusion could not be excluded.

Acridines↗