Fig 1: BAG family molecular chaperone regulator 5 was detected in ejaculated spermatozoa via WB (A; predicted mass = 54 kDa) and immunocytochemistry (B), where it was detected to localize in the acrosome.After priming, BAG5 still remained localized to what remained of the acrosome (C). After 4 and 24 hr of cell-free system exposure, BAG5 was detected in the mitochondrial sheath of the treated spermatozoa (D and E). BAG5 was detected in the cytoplasm in zygotes 15 hr post structures (F) and 25 hr post fertilization, with no obvious association with the fertilizing sperm structures or their remnants (G).