The frequency of heterologous synapsis increases with aging in Robertsonian heterozygous male mice

Chiara Vasco, Marcia Manterola, Jesus Page, Maurizio Zuccotti, Roberto De La Fuente, Carlo Alberto Redi, Raul Fernandez-Donoso, Silvia Garagna

Research output: Contribution to journalArticlepeer-review

Abstract

The house mouse is characterised by highly variable chromosome number due to the presence of Robertsonian (Rb) chromosomes. During meiosis in Rb heterozygotes, intricated chromosomal figures are produced, and many unsynapsed regions are present during the first prophase, triggering a meiotic silencing of unsynapsed chromatin (MSUC) in a similar mode to the sex chromosome inactivation. The presence of unsynapsed chromosome regions is associated with impaired spermatogenesis. Interestingly, in male mice carrying multiple Rb trivalents, the frequency of germ cell death, defective tubules, and altered sperm morphology decreases during aging. Here, we studied whether synapsis of trivalent chromosomes and MSUC are involved in this improvement. By immunocytochemistry, we analysed the frequency of unsynapsed chromosomes and of those positive to γH2AX (a marker of MSUC) labelling in spermatocytes of 3-, 5- and 7-month-old Rb heterozygotes. With aging, we observed a decrease of the frequency of unsynapsed chromosomes, of spermatocytes bearing them and of trivalents carrying γH2AX-negative unsynapsed regions. Our quantitative results show that both synapsis and MSUC processes are better accomplished during male aging, partially accounting for the improvement of spermatogenesis.

Original languageEnglish
Pages (from-to)269-278
Number of pages10
JournalChromosome Research
Volume20
Issue number2
DOIs
Publication statusPublished - Feb 2012

Keywords

  • Aging
  • Asynapsis
  • Meiosis
  • MSUC
  • Robertsonian translocation
  • Spermatogenesis

ASJC Scopus subject areas

  • Genetics

Fingerprint Dive into the research topics of 'The frequency of heterologous synapsis increases with aging in Robertsonian heterozygous male mice'. Together they form a unique fingerprint.

Cite this