Differences in injection of X. laevis and X. tropicalis. Includes: X. tropicalis lays eggs about 4 hours after a boost of hCG; In vitro fertilization is not nearly as efficient in trops compared to laevis; X. tropicalis embryos are much softer than X. laevis embryos; X. tropicalis embryos whose jelly coats are removed by cysteine have a loose sticky vitelline membrane; X. tropicalis do not have a "summer slump". - [Read Differences in Injection of X. laevis and X. tropicalis]
Mature Tetrahymena cells of opposite mating types are starved under appropriate salt conditions. The mating types are then combined to costimulate through cell-cell interaction. Loose pairs and then firm, irreversible pairs of cells of opposite mating types form. This method consistently results in a high percentage of pairing (usually greater than 80%) and good synchrony. - [Read Induction of Conjugation in Tetrahymena Protocol]