DNase I sensitivity ofMicrotus agrestisactive, inactive and reactivated X chromosomes in mouse-Microtuscell hybrids

✍ Scribed by Bat-Sheva Kerem; Veronika Kottusch-Geiseler; Vera Kalscheuer; Ruth Goitein; Karl Sperling; Menashe Marcus

• Book ID: 104713719
• Publisher: Springer
• Year: 1988
• Tongue: English
• Weight: 727 KB
• Volume: 96
• Category: Article
• ISSN: 0009-5915
• DOI: 10.1007/bf00302362

✦ Synopsis

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.