ISSN:
1432-1211
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract When Thy-1− cell lines derived from different Thy-1+ murine thymic lymphomas are analyzed by complementation analysis, most fall into the “A” complementation class. A possible explanation for this result is that the Class A phenotype is due to a mutation in a gene on the X chromosome. To test this idea, selection for 6-thioguanine resistance was carried out on Thy-1+ hybrid cell lines between complementary Class A and Class C Thy-1− mutant cell lines. In some hybrid clones, there was complete concordance between 6-thioguanine resistance and a change of the phenotype of the hybrid from Thy-1+ to Thy-1−. Detailed study of one of these hybrid clones showed that 6-thioguanine resistance was accompanied by loss of hypoxanthine guanine phosphoribosyltransferase activity and that the Thy-1− phenotype was attributable to loss of the gene complementing the Class A Thy-1− mutation. Other hybrid clones, however, had some thioguanine resistant lines which remained Thy-1+. The degree of concordance was a characteristic of the particular hybrid clone examined and subclones which showed complete concordance could be derived from clones showing incomplete concordance. The variability in the degree of concordance between 6-thioguanine resistance and the Thy-1− phenotype in different hybrid cell lines was also seen among individual hybrid clones isolated from a fusion between a Class A mutant and normal spleen cell blasts. We conclude from these results that the basis of the Class A Thy-1− phenotype is genetic, but given the variability in the degree of linkage observed, we cannot determine whether the gene determining the Class A mutant phenotype is X-linked in the normal situation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01561574
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