Sexual Plant Reproduction

, Volume 23, Issue 1, pp 29–37

Chromosome and DNA methylation dynamics during meiosis in the autotetraploid Arabidopsis arenosa

  • Ana Carvalho
  • Margarida Delgado
  • Augusta Barão
  • Márcia Frescatada
  • Edna Ribeiro
  • Craig S. Pikaard
  • Wanda Viegas
  • Nuno Neves
Original Article

DOI: 10.1007/s00497-009-0115-2

Cite this article as:
Carvalho, A., Delgado, M., Barão, A. et al. Sex Plant Reprod (2010) 23: 29. doi:10.1007/s00497-009-0115-2

Abstract

Variation in chromosome number due to polyploidy can seriously compromise meiotic stability. In autopolyploids, the presence of more than two homologous chromosomes may result in complex pairing patterns and subsequent anomalous chromosome segregation. In this context, chromocenter, centromeric, telomeric and ribosomal DNA locus topology and DNA methylation patterns were investigated in the natural autotetraploid, Arabidopsis arenosa. The data show that homologous chromosome recognition and association initiates at telomeric domains in premeiotic interphase, followed by quadrivalent pairing of ribosomal 45S RNA gene loci (known as NORs) at leptotene. On the other hand, centromeric regions at early leptotene show pairwise associations rather than associations in fours. These pairwise associations are maintained throughout prophase I, and therefore likely to be related to the diploid-like behavior of A. arenosa chromosomes at metaphase I, where only bivalents are observed. In anthers, both cells at somatic interphase as well as at premeiotic interphase show 5-methylcytosine (5-mC) dispersed throughout the nucleus, contrasting with a preferential co-localization with chromocenters observed in vegetative nuclei. These results show for the first time that nuclear distribution patterns of 5-mC are simultaneously reshuffled in meiocytes and anther somatic cells. During prophase I, 5-mC is detected in extended chromatin fibers and chromocenters but interestingly is excluded from the NORs what correlates with the pairing pattern.

Keywords

MeiosisAutopolyploidDNA methylationArabidopsis arenosa

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Ana Carvalho
    • 1
  • Margarida Delgado
    • 1
    • 2
  • Augusta Barão
    • 1
  • Márcia Frescatada
    • 1
  • Edna Ribeiro
    • 1
  • Craig S. Pikaard
    • 3
  • Wanda Viegas
    • 1
  • Nuno Neves
    • 1
    • 4
  1. 1.Centro de Botânica Aplicada à Agricultura, Instituto Superior de AgronomiaTechnical University of LisbonLisbonPortugal
  2. 2.Faculdade de Engenharias e Ciências NaturaisUniversidade Lusófona de Humanidades e TecnologiasLisbonPortugal
  3. 3.Biology DepartmentWashington UniversitySt. LouisUSA
  4. 4.Departamento de Ciências da Vida, Faculdade de Ciências e TecnologiaUniversidade Nova de LisboaCaparicaPortugal