A possible active segment on the inactive human X chromosome
- PMID: 1009814
- DOI: 10.1007/BF00328482
A possible active segment on the inactive human X chromosome
Abstract
An idic(Xp--) in which the two X chromosomes are attached short arm to short arm, and which thus has two b regions (the Q-dark segment next to the centromere on Xp) between the inactivation centers, assumed to be situated on the Q-dark region next to the centromere on Xq, showed 63.8% bipartite Barr bodies as compared with 22.2% formed by idic(Xq--). In addition, the mean distance of the two parts of the Barr bodies in the fibroblasts of a patient with idic(Xp--) is significantly greater than in the cases with one or no b region. Contrary to the other patients with abnormal X chromosomes, the buccal cells of a woman idic(Xp--) showed a number of bipartite Barr bodies. -- To explain these observations we have put forward the hypothesis that the b region on the Xp always remains active and thus, when the rest of the chromosome forms a Barr body, this segment is extended, allowing the two parts of the X chromatin to get farther apart and at the same time increasing the percentage of bipartite bodies.
Similar articles
-
The similarity of phenotypic effects caused by Xp and Xq deletions in the human female: a hypothesis.Hum Genet. 1990 Jul;85(2):175-83. doi: 10.1007/BF00193192. Hum Genet. 1990. PMID: 2370045
-
Structure and Barr body formation of an Xp + chromosome with two inactivation centers.Am J Hum Genet. 1977 Jan;29(1):83-93. Am J Hum Genet. 1977. PMID: 299980 Free PMC article.
-
Replication and inactivation of a dicentric X formed by telomeric fusion.Am J Obstet Gynecol. 1980 Apr 1;136(7):904-11. doi: 10.1016/0002-9378(80)91049-2. Am J Obstet Gynecol. 1980. PMID: 7361838
-
Structural anomalies of the X chromosome: personal observation and review of non-mosaic cases.Clin Genet. 1982 Feb;21(2):145-59. doi: 10.1111/j.1399-0004.1982.tb00752.x. Clin Genet. 1982. PMID: 7044622 Review.
-
Mosaicism 45,X/46,X, t dic(Xp:Xp) in a girl with short stature.Ann Genet. 1990;33(4):234-8. Ann Genet. 1990. PMID: 2095706 Review.
Cited by
-
X chromosome constitution and the human female phenotype.Hum Genet. 1980;54(2):133-43. doi: 10.1007/BF00278961. Hum Genet. 1980. PMID: 7390488
-
Position of the human X inactivation center on Xq.Hum Genet. 1979;50(1):59-64. doi: 10.1007/BF00295590. Hum Genet. 1979. PMID: 468261
-
DNA replication and inactivation patterns in structural abnormality of sex chromosomes. I.X-A translocations, rings, fragments, isochromosomes, and pseudo-isodicentrics.Hum Genet. 1984;67(1):37-47. doi: 10.1007/BF00270556. Hum Genet. 1984. PMID: 6745924
-
The similarity of phenotypic effects caused by Xp and Xq deletions in the human female: a hypothesis.Hum Genet. 1990 Jul;85(2):175-83. doi: 10.1007/BF00193192. Hum Genet. 1990. PMID: 2370045
-
Partial trisomy 14 (q23 leads to qter) via segregation of a 14/X translocation.Am J Hum Genet. 1983 Jul;35(4):635-44. Am J Hum Genet. 1983. PMID: 6881140 Free PMC article.