Drugs, Reagents and Instruments

Dexamethasone (Dex; MP Biomedicals, Santa Ana, CA, USA) was dissolved in dimethyl sulfoxide (DMSO; Sigma-Aldrich, Japan) to obtain stock solution at a concentration of 10mM and stored at −20°C. Quercetin (QU; Tianjinshilang, Tianjin, China; quercetin content 90%) was identified and determined by HPLC with the standard reference (National Institutes for Food and Drug Control, Beijing, China), and dissolved and diluted to a final concentration of 16 μM in egg water before use. Alizarin red (MP Biomedicals, Santa Ana, CA, USA) was used for staining. Small embryo incubator IPP 400 (Memmert, Schwabach, Germany) and Laser confocal microscope TCS SP5II (LSCM; Leica, Hamburg, Germany) were also used in the experiments.