Chromosome Research

, Volume 10, Issue 7, pp 549–560

Differential association of SMC1α and SMC3 proteins with meiotic chromosomes in wild-type and SPO11-deficient male mice

  • Rosalina D. James
  • John A. Schmiesing
  • Antoine H. F. M. Peters
  • Kyoko Yokomori
  • Christine M. Disteche
Article

DOI: 10.1023/A:1020910601858

Cite this article as:
James, R.D., Schmiesing, J.A., Peters, A.H.F.M. et al. Chromosome Res (2002) 10: 549. doi:10.1023/A:1020910601858

Abstract

SMC proteins are components of cohesin complexes that function in chromosome cohesion. We determined that SMC1α and SMC3 localized to wild-type mouse meiotic chromosomes, but with distinct differences in their patterns. Anti-SMC3 coincided with axial elements of the synaptonemal complex, while SMC1α was observed mainly in regions where homologues were synapsed. This pattern was especially visible in pachytene sex vesicles where SMC1α localized only weakly to the asynapsed regions. At diplotene, SMC3, but not SMC1α, remained bound along axial elements of desynapsed chromosomes. SMC1α and SMC3 were also found to localize along meiotic chromosome cores of Spo11 null spermatocytes, in which double-strand break formation required for DNA recombination and homologous pairing were disrupted. In Spo11−/− cells, SMC1α localization differed from SMC3 again, confirming that SMC1α is mainly associated with homologous or non-homologous synapsed regions, whereas SMC3 localized throughout the chromosomes. Our results suggest that the two cohesin proteins may not always be associated in a dimer and may function as separate complexes in mammalian meiosis, with SMC1α playing a more specific role in synapsis. In addition, our results indicate that cohesin cores can form independently of double-strand break formation and homologous pairing.

meiotic chromosomesSMC1αSMC3SPO11

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Rosalina D. James
    • 1
  • John A. Schmiesing
    • 2
  • Antoine H. F. M. Peters
    • 3
    • 4
  • Kyoko Yokomori
    • 2
  • Christine M. Disteche
    • 1
  1. 1.Department of PathologyUniversity of WashingtonSeattle
  2. 2.Department of Biological ChemistryUniversity of CaliforniaIrvineUSA
  3. 3.Department of GeneticsUniversity of WashingtonSeattle
  4. 4.Research Institute of Molecular PathologyViennaAustria