Seminiferous Tubules (human)
Ovary (cat)
Ovum (squirrel)
Primordial Follicle (human)
Secondary Follicle (human)
Addition of Yolk to Oocyte by Follicle Cells
Maturing Secondary Follicle (monkey)
Secondary Ooocyte in Antral Follicle (human)
Oogenesis – formation of polar bodies (rat, human, and mouse, respectively)
Meiosis (Click on the link to run the animation) (Close the movie window to return to this presentation)
Frog (Xenopus) Oogenesis
Fertilization - Acrosome Reaction and Cortical Reaction
Sea Urchin rhodamine phalloidin staining of fertilization cone (explosive actin polymerization)
Inositol triphosphate (IP3) is a second messenger released from phosphatidyl inositol bisphosphate (PIP) by phospholipase C, and binds to and activates a calcium channel in the endoplasmic reticulum, releasing a wave of Ca ++ that spreads across the ovum. Calcium ion stimlates the release of cortical granules to the perivitelline space, which widens as a slow block to polyspermy and deactivates bindin receptors.
Sea Urchin Cortical Reaction phase contrast left intracellular Ca ++ right
Sea Urchin fusion of egg and sperm pronuclei Fusioneggspermpronuclei.mov
Ascidean Cortical Rotation
frog (Xenopus) cortical rotation (follows gravitational rotation) corticalrotation.mov
frog (Xenopus) gravitational rotation, Cleavage fert2.mov
Branchiostoma Cleavage and Blastulation
Xenopus Blastulation
frog (Xenopus) Blastulation xenopus embryo.mov
Branchiostoma Gastrulation
Xenopus Zygote Cytoplasmic Fate Map
Xenopus median section blastulation – bottle cells
Xenopus Vegetal and Median Gastrulation
Frog (Xenopus) Gastrulation, formation of yolk plug, Neurulation RKellergastrulation.mov
Xenopus Median and Parasagittal Gastrulation
Frog (Xenopus) Gastrulation – median optical section froggastmedianopticalsection.mov
Keller sandwich Cutout (frog) sandwich_cutout.mov
Keller sandwich explant (chordaneural elongation) Kellersandwichdorsallipexplant.mov
Branchiostoma Neurulation
Xenopus Neurulation