Amphibian Research Group, Univ of Newcastle
3 hr 45 min PI: 4 hr PI: blastula 4 hr 30 min PI:
early blastula                          late blastula
Embryonic development in Lim. tasmaniensis IVF controls.
Time = 1-4 hr 30 min PI.
In normal embryonic development cleavage furrows form perpendicular to the original cleavage furrow and produce symmetrical cells.  As cellular divisions occur, cells increase in number and decrease in size.  From 16 cells, divisions at the animal pole occur ahead of divisions at the vegetal pole (blastula).
1 hr PI: Zygote              1 hr 45 min PI: 2 cell         2 hr 15 min PI: 4 cell
(polar body pit, circle)
    2 hr 45 min PI: 8 cell       3 hr 15 min PI: 16 cell         3 hr 30 min PI: 32 cell
Spotted Grass Frog
Embryos:
Danielle Herbert
(Univ Newc.)