Influence of the mucin coat on the survival of rabbit and mouse embryos stored at 0 degrees C.
To examine the factors affecting the survival of refrigerated embryos, rabbit and mouse morulae were stored at 0 degrees C in modified phosphate-buffered saline (PB1) or in PB1 containing 0.75 M sucrose. Survival was defined as the ability to develop into an expanded blastocyst in culture. The data was analyzed with special reference to the presence of a mucin coat around the embryos. When rabbit morulae were stored in isotonic PB1 for 2, 4, 6, and 8 days, survival rates were 98%, 88%, 85%, and 50%, respectively. However, if the mucin coat had been removed before storage, the rates were lower (95%, 75%, 36%, and 3%, respectively). Sucrose impaired the survival of rabbit morulae irrespective of the presence of the mucin coat. Only 11% of mouse morulae survived 2 days of storage in PB1 medium, but if the medium contained sucrose, survival rates after storage for 2, 3, 4, and 5 days were higher (83%, 55%, 31%, and 7%, respectively). To provide them with a mucin coat around the zona pellucida, mouse embryos were incubated in a rabbit oviduct. Survival rates of these embryos after storage in the presence of sucrose did not decrease over 4 days of refrigeration (98-92%), and the rates after storage for 5, 6, and 7 days were 65%, 40%, and 30%, respectively; embryos that had been stored for 5 days were transferred to recipient mice, and live young were born. Agar embedding of mouse morulae did not have the same effect as the mucin coat.(ABSTRACT TRUNCATED AT 250 WORDS)
Kasai
M
M
Laboratory of Animal Science, College of Agriculture, Kochi University, Japan.
Hiraishi
M
M
Nureki
I
I
Zhu
S E
SE
Sakurai
T
T
Machida
T
T
D000818:Animals; D046508:Culture Techniques; D004622:Embryo, Mammalian / Q000502:physiology; D005260:Female; D006982:Hypertonic Solutions; D007552:Isotonic Solutions; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009077:Mucins / Q000502:physiology*; D011817:Rabbits; D012034:Refrigeration; D013395:Sucrose; D015044:Zona Pellucida / Q000502:physiology
D006982:Hypertonic Solutions; D007552:Isotonic Solutions; D009077:Mucins; D013395:Sucrose