Transició de proteïnes nuclears i condensació de la cromatina espermiogènica : proposta d'un model ancestral de l'espermiogènesi nuclear

Authors

  • Kathryn Kurtz
  • Núria Saperas Plana
  • Juan Ausió Casas
  • Manuel Chiva i Royo

Abstract

We study the correlation between: i) nuclear protein exchange in spermiogenic nuclei, ii) the chromatin condensation pattern, and iii) the acetylation of histones. The study is applied to four species which demonstrate an increasing complexity in nuclear protein transitions. In Sparus aurata histones remain in sperm nuclei. In Dicentrarchus labrax and Monodonta turbinata the histones are substituted by a much more basic molecules. In spermiogenesis of Sepia officinalis histones are replaced by a precursor protamine, which is transformed into the protamine in the last phases of spermiogenesis. The results indicate that in the first phase of spermiogenesis of all four species an identical process is involved, in which: i) the chromatin looses typical somatic structure and ends up organized into granules measuring 20 nm in diameter, and ii) the histones undergo a moderate acetylation.

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Published

2009-04-24