An Easy Protocol for Studying Chromatin and Recombination Protein Dynamics during Arabidopsis thaliana Meiosis: Immunodetection of Cohesins, Histones and MLH1

作者：Chelysheva L^*; Grandont L; Vrielynck N; le Guin S; Mercier R; Grelon M

来源：Cytogenetic and Genome Research, 2010, 129(1-3): 143-153.

DOI：10.1159/000314096

• Arabidopsis
• Chiasmata
• Meiosis
• MLH1
• Mutants
• Recombination

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.

• 出版日期2010