TABLE 2.

Demonstration that only opaque-phase cells of opposite mating types undergo fusiona

Mating typesStrainsCell typesFusionb
MTLα × MTLaWO-1 × L26Opaque × opaque+
MTLα × MTLaWO-1 × 12COpaque × opaque+
MTLα × MTLaWO-1 × P37005Opaque × opaque+
MTLα × MTLaWO-1 × P75063Opaque × opaque+
MTLα × MTLa19F × L26Opaque × opaque+
MTLα × MTLa19F × 12COpaque × opaque+
MTLα × MTLa19F × P37005Opaque × opaque+
MTLα × MTLa19F × P75063Opaque × opaque+
MTLα × MTLaP78048 × L26Opaque × opaque+
MTLα × MTLaP78048 × 12COpaque × opaque+
MTLα × MTLaP78048 × P37005Opaque × opaque+
MTLα × MTLaP78048 × P75063Opaque × opaque+
MTLα × MTLαWO-1 × 19FOpaque × opaque
MTLα × MTLαWO-1 × P78048Opaque × opaque
MTLα × MTLα19F × P78048Opaque × opaque
MTL a × MTLaL26 × 12COpaque × opaque
MTL a × MTLaL26 × P37005Opaque × opaque
MTL a × MTLaL26 × P75063Opaque × opaque
MTL a × MTLa12C × P37005Opaque × opaque
MTL a × MTLa12C × P75063Opaque × opaque
MTL a × MTLaL26 × 3153AOpaque × white
MTL a × MTLaP37005 × 3153AOpaque × white
MTL a × MTLa12C × 3153AOpaque × white
MTLα × MTLaWO-1 × 3153AOpaque × white
MTLα × MTLa19F × 3153AOpaque × white
MTLα × MTLaP78048 × 3153AOpaque × white
MTLα × MTLaWO-1 × L26Opaque × white
MTLα × MTLa19F × L26White × opaque
MTLα × MTLa19F × 12CWhite × opaque
MTLα × MTLα19F × WO-1White × opaque
  • a In this case, fusion in cultures was assessed microscopically 24 and 96 h after cells were mixed.

  • b Mixed cultures were grown for at least 4 days and then analyzed microscopically for fusions. For each culture, 20 fields of cells comparable to those in Fig. 1A through D were scrutinized. +, fusion occurred; −, no fusion occurred.