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Chromosoma

, Volume 103, Issue 9, pp 635–641 | Cite as

The chlorarachniophyte: a cell with two different nuclei and two different telomeres

  • Paul Gilson
  • Geoffrey I. McFadden
Article

Abstract

Chlorarachniophyte algae contain a complex chloroplast derived from the endosymbiosis of a eukaryotic alga. The reduced nucleus of the endosymbiont, the nucleomorph, is located between the inner and outer pair of membranes surrounding the chloroplast. The nucleomorph of chlorarachniophytes has previously been demonstrated to contain at least three small linear chromosomes. Here we describe cloning the end of the smallest nucleomorph chromosome which is shown to carry a telomere consisting of a tandemly repeated 7 bp sequence, TCTAGGG. Using the telomere repeat as a probe, we show that nucleomorph telomeres display typical hetero-disperse size distribution. The nucleomorph is shown to contain only three chromosomes with a haploid genome size of just 380kb. All six nucleomorph chromosome termini are identical with an rRNA cistron closely linked to the telomere. The nucleomorph chromosomes thus have relatively large inverted repeats at their ends. Chromosomes from the host nucleus are shown to have a different telomere repeat motif to that of the nucleomorph chromosomes.

Keywords

Developmental Biology Genome Size Invert Repeat Repeat Motif Telomere Repeat 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • Paul Gilson
    • 1
  • Geoffrey I. McFadden
    • 1
  1. 1.Plant Cell Biology Research Centre, School of BotanyUniversity of MelbourneParkvilleAustralia

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