Analyzing Intact Meiocytes of Wild-type Arabidopsis thaliana and Meiotic Mutants, ahp2 and spo11-2-2, using Confocal Microscopy

The purpose of this study was to assess the utility of confocal microscopy to examine nuclear organization and chromosome pairing for intact Arabidopsis male meiocytes. The efficiency of the confocal technique was evaluated by analyzing wild-type nuclei throughout meiosis. Early-mid leptotene meiocytes demonstrated the presence of several propidium iodide stained signals within the nucleolus prior to the onset of chromosome pairing in zygotene. Pachytene chromosomes were completely paired and were traced to confirm the Arabidopsis karyotype. Additionally, the confocal technique was employed on meiotic mutants, ahp2 and spo11-2-2, to characterize their meiotic defects. Leptotene ahp2 meiocytes and zygotene meiocytes in both meiotic mutants appeared normal. In contrast, pachytene meiocytes in ahp2 and spo11-2-2 mutants demonstrated a wide-spread lack of paired chromosomes. Despite this general lack of pairing, a small amount of chromosome pairing was detected on the short arms of NOR-bearing chromosomes 2 and 4 in ahp2 and spo11-2-2 mutants.MAS