Representative 2-D gels of proteins extracted from the plasma membrane head isolated from fresh (A), cryopreserved with DMSO (B), with DMSO plus AFPI (C) and with DMSO plus AFPIII (D) gilthead sea bream spermatozoa.

Extracted flagellar proteins (60 µg) were loaded onto non-linear IPG strips pH 3–10, and following isoelectric focusing were separated by 12.5% SDS–PAGE. Gels were silver stained as described in Materials and Methods. Spots that changed their expression after cryopreservation procedure are highlighted with a circle.