Capacitation and fertilizing ability of BALB/c mouse spermatozoa collected from different regions of the cauda epididymis.

摘要

The capacitation rates of spermatozoa collected from 3 regions of the cauda epididymis were studied by chlortetracycline fluorescence assay. In addition, fertilizing ability was examined by in vitro fertilization with cumulus-intact and cumulus-freemouse eggs. Immediately after collection, spermatozoa showed no significant differences in capacitation rates. However, the capacitation rates in the proximal region were significantly higher than in distal region 60 min of incubation, and the mid region at 120 min of incubation. Non-preincubated spermatozoa regardless of the collection region in the cauda epididymis showed signs of low fertilizing ability in cumulus-intact (9-10%) and cumulus-free (0-4%) mouse eggs at 6 h after insemination. After 2 hof sperm preincubation, fertilization rates of spermatozoa collected from the proximal and distal regions were only slightly increased (26-44%) but those of the mid region were greatly increased in both cumulus-intact (68%) and cumulus-free (61%) mouseeggs. These results suggest that the fertilizing ability of BALB/c mouse spermatozoa is changed during transit in the cauda epididymidis, and that spermatozoa from the mid region of the cauda could be utilized efficiently for in vitro fertilization in BALB/c mice.