The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Molecular evidence for a relationship between LINE-1 elements and X chromosome inactivation: the Lyon repeat hypothesis.

X inactivation is a chromosome-specific form of genetic regulation in which thousands of genes on one homologue become silenced early in female embryogenesis. Although many aspects of X inactivation are now understood, the spread of the X inactivation signal along the entire length of the chromosome remains enigmatic. Extending the Gartler-Riggs model [Gartler, S. M. & Riggs, A. D. (1983) Annu. Rev. Genet. 17, 155-190], Lyon recently proposed [Lyon, M. F. (1998) Cytogenet. Cell Genet. 80, 133-137] that a nonrandom organization of long interspersed element (LINE) repetitive sequences on the X chromosome might be responsible for its facultative heterochromatization. In this paper, we present data indicating that the LINE-1 ( L1) composition of the human X chromosome is fundamentally distinct from that of human autosomes. The X chromosome is enriched 2-fold for L1 repetitive elements, with the greatest enrichment observed for a restricted subset of LINE-1 elements that were active <100 million years ago. Regional analysis of the X chromosome reveals that the most significant clustering of these elements is in Xq13-Xq21 (the center of X inactivation). Genomic segments harboring genes that escape inactivation are significantly reduced in L1 content compared with X chromosome segments containing genes subject to X inactivation, providing further support for the association between X inactivation and L1 content. These nonrandom properties of L1 distribution on the X chromosome provide strong evidence that L1 elements may serve as DNA signals to propagate X inactivation along the chromosome.[1]


  1. Molecular evidence for a relationship between LINE-1 elements and X chromosome inactivation: the Lyon repeat hypothesis. Bailey, J.A., Carrel, L., Chakravarti, A., Eichler, E.E. Proc. Natl. Acad. Sci. U.S.A. (2000) [Pubmed]
WikiGenes - Universities