An easy protocol for studying chromatin and recombination protein dynamics during Arabidopsis thaliana meiosis: immunodetection of cohesins, histones and MLH1

Cytogenet Genome Res. 2010 Jul;129(1-3):143-53. doi: 10.1159/000314096. Epub 2010 Jul 13.


Plant meiosis studies have enjoyed a fantastic boom in recent years with the use of Arabidopsis thaliana as a model not only for molecular genetics and genomics but also for cytogenetics. In this article we describe a new protocol for immunolabelling meiotic proteins that allows the detection of a large range of proteins on strongly spread chromosomes throughout the entire meiotic process. We used this method to immunodetect MLH1, a crucial component of the meiotic recombination machinery, and found that it can be visualised as foci from pachytene to diakinesis, where it co-localises with chiasmata. The mean MLH1 foci number per meiotic cell at diakinesis was 8.4 for WS-4 and 9.95 for Col-0, with the number of foci per bivalent ranging from 1 to 5. We also analysed MLH1 distribution within bivalents and found that they were not restricted to specific chromosomal regions. The analysis of MLH1 foci formation in the Atzip4 mutant, where class I crossover (CO) formation is prevented, revealed that residual chiasmata were not labelled by MLH1, strongly suggesting that MLH1 antibodies only label class I COs in Arabidopsis. It thus appears that the 'obligatory CO' is systematically labeled by MLH1 and is generated through the class I pathway.

MeSH terms

  • Adenosine Triphosphatases / immunology
  • Adenosine Triphosphatases / metabolism
  • Animals
  • Antibodies
  • Arabidopsis / cytology*
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / immunology
  • Arabidopsis Proteins / metabolism*
  • Cell Cycle Proteins / metabolism
  • Chromatin / genetics
  • Chromatin / metabolism
  • Chromosomal Proteins, Non-Histone / metabolism
  • Chromosomes, Plant / genetics
  • Chromosomes, Plant / metabolism
  • Cohesins
  • Crossing Over, Genetic
  • Cytogenetic Analysis / methods*
  • Histones / metabolism
  • Immunohistochemistry / methods*
  • Meiosis / genetics*
  • Meiosis / physiology
  • MutL Protein Homolog 1
  • Rats
  • Recombination, Genetic


  • Antibodies
  • Arabidopsis Proteins
  • Cell Cycle Proteins
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • Histones
  • Adenosine Triphosphatases
  • MLH1 protein, Arabidopsis
  • MutL Protein Homolog 1