Asci from h90 meiosis.
Cells of an h90 strain were washed and spotted on a supplemented SPA plate, which was incubated for 3 d at 25°. A sample of the cell-ascus mixture was observed under a differential interference contrast microscope and photographed. (Left) The linear ascus (A) has the appearance of an azygotic ascus, whereas the curved ascus (B) has that of a zygotic ascus. A zygote (Z), an unmated cell (C), and a spore (S) from spontaneous lysis of an ascus are also visible in this rare field. (Right) A more typical field of asci, one of which (Z) is immature.