Hypervariable ultra-long telomeres in mice

  title={Hypervariable ultra-long telomeres in mice},
  author={David Kipling and Howard J. Cooke},
TELOMERE structure and behaviour is less well understood in vertebrates than it is in ciliates and yeasts (reviewed in ref. 1). Like all other eukaryotic chromosomes, those of vertebrates terminate in an array of a short repeated sequence. In vertebrates this sequence is (TTAGGG)n, as shown by in situ hybridization2,3. In humans, these terminal repeats are heterogeneous in length, averaging about 10 kilobases in blood cells4–6. Here we report the structure and inheritance of the terminal… 

Telomere Variation in Xenopus laevis

The sequence organization of Xenopus laevis telomeres is investigated by use of the vertebrate telomeric repeat (TTAGGG) n and blot hybridization analysis and data are consistent with a model for chromosome behavior that involves a significant amount of DNA rearrangement at telomerres.

Telomeres in the chicken: genome stability and chromosome ends.

The overall research objectives are to understand the organization of the telomere arrays in chicken in the context of the unusual organization and specialized features of this higher vertebrate genome and to elucidate the role telomeres play in genome stability impacting cell function and life span.

Genomic organization of the Drosophila telomere retrotransposable elements.

The emerging sequence of the heterochromatic portion of the Drosophila melanogaster genome gives the first genome-wide view of the chromosomal distribution of the telomeric retrotransposons, HeT-A, TART, and Tahre.

Mammalian meiotic telomeres: protein composition and redistribution in relation to nuclear pores.

It is demonstrated that telomere repositioning during meiotic prophase occurs in sectors of the nuclear envelope that are distinct from nuclear pore-dense areas and tankyrase, a poly-(ADP-ribose)polymerase at somatic telomeres and nuclear pores, forms small signals at ends of human meiotic chromosome cores.

Telomere length in reproduction

This review focuses on the function, structure and length dynamics of the telomere in the reproductive process, and finds that spermatozoa, are terminally differentiated cells, have longer telomeres than spermatogonia and pachytene sperMatocytes.

Telomeric repeats far from the ends: mechanisms of origin and role in evolution

Analysis of the flanking sequences suggested that s-ITSs were inserted during the repair of DNA double-strand breaks that occurred in the course of evolution, and an extensive comparative analysis of the s- ITS loci and their orthologous ‘empty’ loci confirmed this hypothesis.

The terminal DNA structure of mammalian chromosomes

It is shown here that an overhang of the strand forming the 3′ ends of the chromosomes, the G‐rich strand, is found at mammalian chromosome ends, and that these overhangs may be considerably larger than previously anticipated.

Regulation of Telomere Length in Mammalian Cells

The ends of linear mammalian chromosomes consist of a simple repeated sequence (T2AG3)n [reviewed in 1,2]. These terminal repeats play a role in prevention of end to end fusion and prot7ection from

Chromosome ends: different sequences may provide conserved functions

  • E. LouisA. Vershinin
  • Biology
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2005
The similarities and diversity that exist among the structural elements, DNA sequences and proteins, that make up terminal domains (telomeres and subtelomeres), and how organisms use these in different ways to fulfil the functions of end‐replication and end‐protection are focused on.

Mouse telocentric sequences reveal a high rate of homogenization and possible role in Robertsonian translocation.

This work has identified large-insert fosmid clones that span the telomere and centromere of several mouse chromosome ends and indicates a possible mechanism for occasional inverted mispairing and recombination between the oppositely oriented TLC and minor satellite repeats to result in Robertsonian translocations.



Structure and variability of human chromosome ends

A direct cloning strategy for telomere-associated DNA was developed based on the relative lack of restriction endonuclease cutting sites near the ends of human chromosomes, indicating that somatic telomeres are unstable and may continuously lose sequences from their termini.

Human telomeres contain at least three types of G-rich repeat distributed non-randomly.

It is demonstrated here that human telomeres do not contain a pure uniform 6 base pair repeat unit but that there are at least three types of repeat, which are present at the ends of most or all human chromosomes.

Cloning of human telomeres by complementation in yeast

A modified yeast artificial chromosome (YAC) vector with only one telomere is described which was used to clone human telomeres by complementation in yeast.

Telomeres shorten during ageing of human fibroblasts

The amount and length of telomeric DNA in human fibroblasts does in fact decrease as a function of serial passage during ageing in vitro and possibly in vivo.

Conservation of the human telomere sequence (TTAGGG)n among vertebrates.

The conservation of the (TTAGGG)n sequence and its telomeric location, in species thought to share a common ancestor over 400 million years ago, strongly suggest that this sequence is the functional vertebrate telomere.

A highly conserved repetitive DNA sequence, (TTAGGG)n, present at the telomeres of human chromosomes.

A highly conserved repetitive DNA sequence, (TTAGGG)n, has been isolated from a human recombinant repetitive DNA library and its similarity to functional telomeres isolated from lower eukaryotes suggest that this sequence is a functional human telomere.

Chromosome ends in Drosophila without telomeric DNA sequences.

Molecular cloning and sequencing of the terminal DNA fragments revealed that the broken ends of the deleted chromosomes do not carry any telomeric DNA sequences, yet the broken chromatids do not fuse to one another.

Construction of a small Mus musculus repetitive DNA library: identification of a new satellite sequence in Mus musculus.

Initial characterizations of this library by colony filter hybridizations have led to the identification of a previously undetected M. musculus minor satellite, which has a 29 base pair region with extensive homology to one of the major satellite repeating subunits.