Electron tomography of mouse LINC complexes at meiotic telomere attachment sites with and without microtubules

Commun Biol. 2019 Oct 14:2:376. doi: 10.1038/s42003-019-0621-1. eCollection 2019.

Abstract

Telomere movements during meiotic prophase I facilitate synapsis and recombination of homologous chromosomes. Hereby, chromosome movements depend on the dynamic attachment of meiotic telomeres to the nuclear envelope and generation of forces that actively move the telomeres. In most eukaryotes, forces that move telomeres are generated in the cytoplasm by microtubule-associated motor proteins and transduced into the nucleus through the LINC complexes of the nuclear envelope. Meiotic LINC complexes, in mouse comprised of SUN1/2 and KASH5, selectively localize to the attachment sites of meiotic telomeres. For a better understanding of meiotic telomere dynamics, here we provide quantitative information of telomere attachment sites that we have generated with the aid of electron microscope tomography (EM tomography). Our data on the number, length, width, distribution and relation with microtubules of the reconstructed structures indicate that an average number of 76 LINC complexes would be required to move a telomere attachment site.

Keywords: Electron microscopy; Nuclear envelope; Spermatogenesis; Telomeres.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Cell Cycle Proteins / metabolism
  • Chromosome Pairing
  • Cytoskeletal Proteins / metabolism
  • Electron Microscope Tomography
  • Male
  • Meiosis
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / metabolism
  • Microtubules / ultrastructure*
  • Multiprotein Complexes / metabolism
  • Multiprotein Complexes / ultrastructure
  • Nuclear Envelope / metabolism
  • Nuclear Envelope / ultrastructure
  • Nuclear Proteins / metabolism
  • Telomere / metabolism
  • Telomere / ultrastructure*
  • Telomere-Binding Proteins / metabolism
  • Testis / metabolism
  • Testis / ultrastructure

Substances

  • Cell Cycle Proteins
  • Cytoskeletal Proteins
  • KASH5 protein, mouse
  • Membrane Proteins
  • Microtubule-Associated Proteins
  • Multiprotein Complexes
  • Nuclear Proteins
  • SUN1 protein, mouse
  • Sun2 protein, mouse
  • Telomere-Binding Proteins