CHROMOSOME ASSIGNMENT OF A MURINE GLUCOCORTICOID RECEPTOR GENE (GRL-1) USING INTRASPECIES SOMATIC-CELL HYBRIDS
CHROMOSOME ASSIGNMENT OF A MURINE GLUCOCORTICOID RECEPTOR GENE (GRL-1) USING INTRASPECIES SOMATIC-CELL HYBRIDS
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DOI:
10.1016/0092-8674(80)90541-3
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发表时间:
1980-01-01
期刊:
影响因子:
64.5
通讯作者:
GEHRING, U
中科院分区:
文献类型:
--
作者:
FRANCKE, U;GEHRING, U
Hybrids between 2 mouse lymphoma cell lines, the glucocorticoid sensitive S49.1 and the resistant EL4 line, are sensitive to the cytolytic steroid effect as long as they retain the S49.1 specific glucocorticoid receptor and the complete chromosome complements contributed by both parental lines. With the use of the semisynthetic glucocorticoid dexamethasone, resistant segregants (dexR) were isolated which have lost the S49.1 specific receptor but retain the EL4 type of receptor. On the average, these segregants have also lost 1 chromosome. A detailed karyotype analysis of both parental cell lines and their hybrids hybrids was carried out using trypsin-Giemsa banding for chromosome identification. S49.1 cells contain 40 apparently normal chromosomes with monosomy X and trisomy 1. EL4 cells have 39 chromosomes, half of which are structurally abnormal. In addition to low levels of random karyotypic variability in S49.1 .times. EL4 hybrids, 1 consistent difference was observed between sensitive (dexS) and dexR sublines: sensitive hybrids contained 3 chromosomes 18 while resistant segregants only had 2. The chromosome 18 contributed by the S49.1 parent was distinguishable from the one contributed by the EL4 cell line by structural variations involving the centromeric heterochromatin and the nucleolar organizer regions. A specific chromosome 18 derived from S49.1 was consistently absent in 3 dexR segregant lines derived from different dexS hybrid clones. Since the dexR segregant hybrids have lost the S49.1 specific glucocorticoid receptor, the gene for the receptor is apparently located on that chromosome 18 which is consistently lost. The other S49.1 derived 18 presumably carries a mutant or silent receptor gene, as S49/1 has previously been shown to have hemizygous levels of the receptor. The usefulness of intraspecies somatic cell hybrids for mapping purposes is emphasized. The overall karyotypic stability of such hybrids allows the identification of specific chromosomes eliminated by selection pressure.