title: The timing of the S phase and other nuclear events in yeast meiosis.
abstract: The length of the premeiotic S phase in individual cells of a homothallic strain of Saccharomyces cerevisiae was determined by pulse-labelling synchronously sporulating cultures with [3H]adenine and following changes in the frequency of cells in S by DNA-specific whole cell autoradiography. The average S phase was found to be at least 2-3 times as long as in mitotic diploids, and it was concluded that activation of replication origins in meiosis is considerably staggered. The timing of S in relation to other meiotic milestones was established by counting different nuclear morphologies visualised by DAPI-fluorescent staining. This allowed tentative identification of pachytene nuclei as well as first and second nuclear divisions.
mesh_terms: D001345:Autoradiography; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D004271:DNA, Fungal / Q000096:biosynthesis; D007399:Interphase; D007700:Kinetics; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000502:physiology; D013172:Spores, Fungal / Q000502:physiology
chemical_list: D004271:DNA, Fungal