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A possible active segment on the inactive human X chromosome.

E Therman·G E Sarto·C Distèche·C Denniston
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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.

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FemaleHumansSex ChromatinSex Chromosome AberrationsSex ChromosomesJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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E Therman, G E Sarto, C Distèche, C Denniston. 1976-12-16. A possible active segment on the inactive human X chromosome.. https://doi.org/10.1007/bf00328482

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