Spr1-GFP is a marker for spore wall permeability.

<p>AN120 (wild-type), AN262 (<i>chs3Δ</i>), and AN264 (<i>dit1Δ</i>) harboring high copy plasmids expressing <i>SPR1-GFP</i> or <i>ssGFP</i> (pRS424-SPR1-GFP or pRS424-ssGFP) were examined by fluorescence microscopy 8 hours or 20 hours after transfer to sporulation medium. Arrows indicate asci displaying fluorescence in the ascal cytoplasm. Bar = 5 µm.