Location of Repository

Do LINEs Have a Role in X-Chromosome Inactivation?

By Mary F. Lyon

Abstract

There is longstanding evidence that X-chromosome inactivation (XCI) travels less successfully in autosomal than in X-chromosomal chromatin. The interspersed repeat elements LINE1s (L1s) have been suggested as candidates for “boosters” which promote the spread of XCI in the X-chromosome. The present paper reviews the current evidence concerning the possible role of L1s in XCI. Recent evidence, accruing from the human genome sequencing project and other sources, confirms that mammalian X-chromosomes are indeed rich in L1s, except in regions where there are many genes escaping XCI. The density of L1s is the highest in the evolutionarily oldest regions. Recent work on X; autosome translocations in human and mouse suggested failure of stabilization of XCI in autosomal material, so that genes are reactivated, but resistance of autosomal genes to the original silencing is not excluded. The accumulation of L1s on the X-chromosome may have resulted from reduced recombination or late replication. Whether L1s are part of the mechanism of XCI or a result of it remains enigmatic

Topics: Review Article
Publisher: Hindawi Publishing Corporation
OAI identifier: oai:pubmedcentral.nih.gov:1510946
Provided by: PubMed Central
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://www.pubmedcentral.nih.g... (external link)
  • Suggested articles

    Preview

    Citations

    1. A chicken transferrin gene in transgenic mice escapes X-chromosome inactivation.
    2. (2000). A shiftfrom reversible to irreversible Xinactivation is triggered during ES cell differentiation. Molecular Cell.
    3. An ectopic human XIST gene can induce chromosome inactivation in postdifferentiation human HT-1080 cells.
    4. (2000). Ashift fromreversible to irreversible Xinactivation is triggered during ES cell differentiation. Molecular Cell.
    5. ClemsonCM,McNeilJA,WillardHF,LawrenceJB.XISTRNA paints the inactive X chromosome at interphase: evidence for a novel RNA involved in nuclear/chromosome structure.
    6. (1998). Comparative methylation analysis of murine transgenes that undergo or escape X-chromosome inactivation. Chromosome Research.
    7. Comparative sequence and X-inactivation analyses of a domain of escape in human Xp11.2 and the conserved segment in mouse.
    8. Comparative studies on Xautosome translocations in the mouse. II. Inactivation of autosomal loci, segregation, and mapping of autosomal breakpoints in five T(X;1)’S.
    9. (2003). CpG islands in human X-inactivation. Annals of Human Genetics.
    10. (1963). Cytogenetics, discussion. In:
    11. (1990). Differential distribution of long and short interspersed element sequences in the mouse genome: chromosome karyotyping by fluorescence in situ hybridization.
    12. (2002). DistributionofLINEsandotherrepetitiveelementsinthekaryotypeof the bat Carollia: implications for X-chromosome inactivation. Cytogenetic and Genome Research.
    13. (1998). Enigma of Y chromosome degeneration: neo-Y and neo-X chromosomes of Drosophila miranda a model for sex chromosome evolution.
    14. (1993). Epigenetic inheritance in mammals. Trends in Genetics.
    15. Four evolutionary strata on the human X chromosome.
    16. Gene action in the X-chromosome of the mouse (Mus musculus L.).
    17. (2003). HansenRS.Xinactivation-specificmethylationofLINE-1elements by DNMT3B: implications for the Lyon repeat hypothesis. Human Molecular Genetics.
    18. High concentrations of long interspersed nuclear element sequence distinguish monoallelically expressed genes.
    19. Human genome organization: Alu, lines, and the molecular structure of metaphase chromosome bands.
    20. Inheritance of a pre-inactivated paternal X chromosome in early mouse embryos.
    21. Initial sequencing and comparative analysis of the mouse genome.
    22. (1999). K e o h a n eA M ,B a r l o wA L ,W a t e r sJ ,B o u r nD ,T u r n e rB
    23. Long-range cis effects of ectopic Xinactivation centres on a mouse autosome.
    24. (1991). Mammalian sex chromosomes: evolution of organization and function. Chromosoma.
    25. Mammalian X-chromosome action: inactivation limited in spread and region of origin.
    26. (1983). Mammalian X-chromosome inactivation. Annual Review of Genetics.
    27. Marsupials and mechanisms of X-chromosome inactivation.
    28. (2002). Molecular and cytogenetic analysis of the spreading of X inactivation in X;autosome translocations. Human Molecular Genetics.
    29. Molecular evidenceforarelationshipbetweenLINE-1elementsandXchromosome inactivation: the Lyon repeat hypothesis.
    30. On the role of unequal exchange in the containment of transposable element copy number.
    31. Position effect variegation in the mouse.
    32. Recent advances in X-chromosome inactivation.
    33. Requirement for Xist in X chromosome inactivation.
    34. Retrotransposon Mys is concentrated on the sex chromosomes: implications for copy number containment.
    35. The DNA sequence of the human X chromosome.
    36. The origin and function of the mammalian Y chromosomeandY-bornegenes—anevolvingunderstanding.
    37. (1998). The spreading of X inactivation into autosomal material of an X;autosome translocation: evidence for a difference between autosomal and X-chromosomal DNA. The American journal of Human Genetics.
    38. (1992). Transposable elements and the evolution of genome organization in mammals.
    39. (2002). Unbalanced X;autosome translocations provide evidence for sequence specificity in the association of XIST RNA with chromatin. Human Molecular Genetics.
    40. Variegated-type position effects in the mouse.
    41. (2005). X chromosome imprinting and inactivation in preimplantation mammalian embryos. Trends in Genetics.
    42. X chromosome inactivation, differentiation, and DNA methylation revisited, with a tribute to Susumu Ohno. Cytogenetic and Genome Research.
    43. (1998). X-chromosome inactivation: a repeat hypothesis. Cytogenetics and Cell Genetics.
    44. X-inactivation profile reveals extensive variability in X-linked gene expression in females.
    45. (1999). Xist RNA exhibits a banded localization on the inactive X chromosome and is excluded from autosomal material in cis. Human Molecular Genetics.

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.