A meiotic time-course for Arabidopsis thaliana

Abstract

A meiotic time-course for Arabidopsis pollen mother cells has been established based on BrdU pulselabelling of nuclear DNA in the meiotic S-phase. Labelled flower buds were sampled at intervals and the progress of labelled cells through meiosis assessed by anti-BrdU antibody detection. The overall duration of meiosis from the end of meiotic S-phase to the tetrad stage, at 18.5C, was 33 h, which is about three times longer than the mitotic cell cycle in seedlings. The onset of leptotene was defined by reference to the loading of the axis-associated protein Asy1, and this permitted the detection of a definite G2 stage, having a maximum duration of 9 h. It is likely, from two independent sources of evidence, that the meiotic S-phase has a duration similar to that of G2. The durations of leptotene and zygotene/pachytene are 6 h and 15.3 h, respectively, but the remaining meiotic division stages are completed very rapidly, within 3 h. The establishment of a meiotic time-course provides a framework for determining the relative timing and durations of key molecular events of meiosis in Arabidopsis in relation to cytologically defined landmarks. In addition, it will be important in a broader developmental context for determining the timing of epigenetic mechanisms that are known or suspected to occur during meiosis.

Ahp2 (Hop2) function in Arabidopsis thaliana (Ler) is required for stabilization of close alignment and synaptonemal complex formation except for the two short arms that contain nucleolus organizer regions

“…We wished to determine whether the severe reduction in stabilized pairing observed in the ahp2 mutant would be correlated with a disruption of normal meiotic progression. For this, we employed BrdU pulse labeling of S-phase male meiocytes (Armstrong et al 2003) to determine the duration of meiosis, in wild type and the ahp2 mutant. The data from these six experiments (three for wild type and three for ahp2) can be found in Supplemental Fig.…”

“…We followed the procedure according to Armstrong et al (2003) except that we examined chromosome squashes (instead of spreads) for the presence of labeled tetrads as the endpoint of meiosis. The samples were dried down, then incubated with 30 µl of fixative (70% ethanol, 50 mM glycine pH 2.0) at −20°C for 20 min.…”

Spatiotemporal Asymmetry of the Meiotic Program Underlies the Predominantly Distal Distribution of Meiotic Crossovers in Barley

“…Initially, progression through meiosis was monitored using a variation of the method developed for Arabidopsis (Armstrong et al, 2003). 59-Bromo-29-deoxyuridine (BrdU) was injected into barley stems before fixing inflorescences at set times and then detecting the appearance of labeled meiotic stages with an antiBrdU Ab.…”

Arabidopsis Cell Division Cycle 20.1 Is Required for Normal Meiotic Spindle Assembly and Chromosome Segregation

“…Persistent incorrect attachment between spindles and kinetochores results in meiotic arrest at metaphase I in animals and delayed meiotic progression in plants (Riehs et al, 2008;Cromer et al, 2012). Studies in multiple organisms estimate that meiotic prophase I occupies ;85% of the meiotic time course (Armstrong et al, 2003;Hamant et al, 2006). In Arabidopsis, meiocytes in an individual anther show a distribution of meiotic stages depending on the time of the day (Wang et al, 2004).…”