Chemotactic behavior of egg mitochondria in response to sperm fusion in mice.

Mitochondria are the powerhouses of eukaryotic cells and their positioning contributes to fertilization and early developmental processes. We report that sperm fusion triggers Ca oscillations and mitochondrial movement toward fused sperm (mitochondrial chemotaxis) in mouse eggs. Mitochondria functioned in Ca storage and were colocalized with endoplasmic reticulum (ER) during Ca oscillations.