Resolution of the sperm motility-stimulating principle of fowl seminal plasma into Ca2+ and an unidentified low molecular weight factor

It was confirmed, using an objective assay of motility, that fowl seminal plasma restores and stimulates the motility of fowl spermatozoa at 40 degrees C in a dose-dependent manner. By separation of a 100,000 g supernatant of fowl seminal plasma with Sephadex G-15, two peaks of motility-stimulating activity were distinguished. One peak coincided with that of calcium and was absent when calcium was removed from the seminal plasma with Dowex 50. The other peak, which accounted for 44% of motility-stimulating activity, contained a low molecular weight, dialysable factor which remains to be identified.