Daily Spermatozoal Production, Epididymal Spermatozoal Reserves and Transit Time of Spermatozoa Through the Epididymis of the Rhesus Monkey

Autoradiographic investigation of sperm transit through the male mouse genital tract after tritiated thymidine incorporation

“…As concerns the period between tracer injection and the appearance of the labeled spermatozoa in each segment of the epididymis, the duration of transit for labeled spermatozoa in the caput and the epididymal corpus is 3 days, precisely the figure reported for mice (Meistrich, 1975) and Wistar rats (Amann et al, 1976). Thus the time required for sperm maturation in the mouse epididymis is within the same range as that of several other mammals (2 to 5.5 days) which was calculated by dividing the number of spermatozoa present in each segment by the number of spermatozoa produced daily in the testis attached to that epididymis (Amann et al, 1976).…”

“…This transit has been calculated in humans, monkeys and in several species of domestic animals (for references see Courot, 1981) as well as in such rodents as rabbits (Amann et al, 1976 ;Orgebin-Crist, 1965), hamsters (Amann et al, 1976), rats (Robb et al, 1978) and guinea-pigs (Frenkel et al, 1973 (Oakberg, 1971) (Oakberg, 1956 ;Clermont and Trott, 1969). Consequently, the recrudescence of the number of labeled sperm cells in the epididymal caput between the 32nd and 33rd day after injection of tritiated thymidine (i. e. 7 to 8 days after the first labeled spermatozoa appear) seems to be attributable to the introduction of A1 spermatogonia (originating in the reserve stem cells labeled previously) into the next seminal epithelial cycle.…”

“…Thus the time required for sperm maturation in the mouse epididymis is within the same range as that of several other mammals (2 to 5.5 days) which was calculated by dividing the number of spermatozoa present in each segment by the number of spermatozoa produced daily in the testis attached to that epididymis (Amann et al, 1976).…”

“…Therefore, it is likely that ejaculation leads to a reduction in the storage time of spermatozoa in the epididymal cauda. On the other hand, it should be noted that a wide range of epididymal transit times has been observed in rodents : 8 days for rats (Robb et al, 1978), 10 to 15 days for hamsters (Amann et al, 1976) and guinea-pigs (Frenkel et al, 1973) and 9 to 10 days for rabbits (Orgebin-Crist, 1965 (Sirlin, 1958 …”

Testicular descent, sperm maturation and capacitation. Lessons from our most distant relatives, the monotremes

“…Spermatozoa take 8 to 17 days to pass through the epididymal ducts of marsupial (Setchell and Carrick 1973) and eutherian (Amann et al 1976) mammals and it is well established that the epididymis plays an essential role in sperm maturation and storage (Jones 1999). The maturation processes that are unique to mammals involve distal migration of the cytoplasmic droplet along the middle piece, condensation of the acrosome in some species, development of the capacity for motility and modification of the plasmalemma, which enables binding to the ovum and possibly other functions.…”