DNAse I sensitivity of Microtus agrestis active, inactive and reactivated X chromosomes in mouse-Microtus cell hybrids

• Published in: Chromosoma 1988-01, Vol.96 (3), p.227-230
• Main Authors: KEREM, B.-S, KOTTUSCH-GEISELER, V, KALSCHEUER, V, GOITEIN, R, SPERLING, K, MARCUS, M
• Format: Article
• Language: English
• Subjects: Animals; Arvicolinae - genetics; Biological and medical sciences; Chromatin - drug effects; Chromatin - ultrastructure; Cytogenetics; Deoxyribonuclease I - pharmacology; Dosage Compensation, Genetic; Euchromatin; Female; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Hybrid Cells - ultrastructure; Hypoxanthine Phosphoribosyltransferase - genetics; Mice; microtus agrestis; Vertebrata; X Chromosome - drug effects
• ISSN: 0009-5915; 1432-0886
• DOI: 10.1007/BF00302362

We isolated Microtus agrestis-mouse somatic cell hybrid clones which had retained either the active or the inactive M. agrestis X chromosome. In both hybrid clones the X chromosomes retained their original chromatin conformation as studied by the in situ nick translation technique--the active X chromosome retained its high sensitivity to DNase I while the inactive one remained insensitive. A clone in which the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene had been spontaneously reactivated was isolated from the hybrid containing the inactive X chromosome. The in situ nick translation technique was used to study possible DNA conformation changes in the euchromatin of the inactive X chromosome with special reference to the reactivated HPRT locus. We found that the euchromatin in this X chromosome exhibited the same low sensitivity to DNase I as is characteristic of the inactive X chromosome.