Fig. 10. Confocal imaging reveals close apposition of mitochondria and ER in a mature egg. (A) General view of a mature egg stained for mitochondria (green) and ER (red) showing mitochondrial aggregates and an ER network dispersed in the whole cytoplasm except in the region of the meiotic spindle (MS) marking the animal pole of the egg. (B,C) Higher magnification view of a mitochondrial aggregate and its relationship with the ER network. It can be clearly seen that strands of ER are intermingled in the aggregate of mitochondria (two of them are indicated by white arrowheads).