Fig. 4.

Flow chart of identification and categorization of the 207 sperm-related proteins from 745 initially identified tissue and fluid proteins. The number of proteins examined was reduced by ignoring 117 structural proteins (unlikely to be secreted) and antibodies were raised to the remaining 628 proteins with 98% success. With the 619 usable antibodies, Western blots revealed that 408 proteins were present in epididymal fluid and 211 not. Two hundred and seven proteins were sperm-located (174 proteins found in epididymal fluid, 33 not) and the remaining proteins (412) were not associated with spermatozoa, whether found in fluid (234) or not (178). Filled sperm head, sperm-located proteins; clear sperm head, non sperm-located proteins; IHC: immunohistochemistry; WB: western blots of epididymal luminal fluid; +65306 positive staining 65307 −65306 negative staining.