Figure 11.

Abnormal sporulation in spo20-KC104. (A) The morphological change in SPBs from dot to crescent forms during meiosis II is normal in spo20-KC104. A wild-type strain (SI53) and a spo20 mutant strain (YN11) were cultured in SSL-N sporulation medium and doubly stained with the anti-Sad1 antibody and DAPI. (B) Forespore membrane formation is abnormal in spo20-KC104. Wild-type (C766–1A) and spo20 mutant (YN11) cells transformed with pAL(spo3-GFP) were cultured in SSL-N to induce meiosis. Fixed cells were examined using DAPI and GFP, as well as anti-Sad1 antibodies. (C) Assembly of forespore membranes and their enclosure of nuclei in spo20-KC104 cells. spo20 mutant (YN11) cells transformed with pAL(spo3-GFP) were cultured in SSL-N to induce meiosis. Forespore membranes and chromatin regions were visualized by GFP and DAPI, respectively. Stained cells were categorized into the following six classes: all four prespores enclose the nucleus (a); four prespores were formed but some of them do not enclose the nucleus (b); three prespores (c), two prespores (d), more than five prespores (e) were formed; forespore membranes were fragmented (f). Bars, 10 μm.