Redundant mechanisms of calcium-induced calcium release underlying calcium waves during fertilization of sea urchin eggs.
In the present work we wanted to verify whether oocytes recovered from preantral follicles were able to acquire calcium activity during follicle culture.
It is uncertain, however, how a high concentration of calcium in the absence of lactate inhibits capacitation.
Our results suggest that these metabolites are involved in diverse signalling pathways such as calcium release and cell cycle signalling.
The calcium injection diminished the nonsaturating receptor potentials by about 70%, and in the ten cells tested, response amplitude was reduced 50 -80%.
These include a regenerative sodium current, the potassium inward rectifier, potassium delayed rectifier and transient outward potassium current, and several calcium currents.
In the present work we determined whether preantral follicle development in vitro also allows oocytes to acquire calcium signalling activity.
Local perinuclear calcium signals associated with mitosis entry in early sea urchin embryos.
