Effect of linoleic acid-albumin in the culture medium on freezing sensitivity of in vitro-produced bovine morulae.
The objective of this study was to improve the survival of in vitro-produced bovine morulae after cry opreservation. In Experiment 1, presumptive zygotes at 20 h post-insemination (hpi) were cultured in a mixture of modified synthetic oviduct fluid (m-SOF)/0.3% BSA and m-SOF/0.3% linoleic acid-albumin from bovine serum (LAA) at 39.0 degrees C in 5% O2, 5% CO2 and 90% N2 (final LAA concentration: 0, 0.01, 0.03, 0.1 or 0.3%). Morulae harvested at 138 hpi were frozen and thawed in m-PBS/0.3% BSA containing 1.5 M ethylene glycol and were cultured for 96 h in m-SOF/10% FBS to assess further development. The post-thaw survival of morulae derived from culture in 0.1% LAA (60%, P < 0.01) and in 0.03% LAA (55%, P < 0.05) was higher than that in 0% LAA (32%). Lowering the LAA concentration below 0.1% resulted in similar rates of morula development as in m-SOF/0.3% BSA. In Experiment 2, zygotes were cultured in m-SOF/0.1% LAA from 20 to 90 hpi and/or from 90 to 138 hpi. Post-thaw survival of morulae that had been exposed to LAA from 20 to 90 hpi (39%) or from 90 to 138 hpi (56%) was higher than that of morulae cultured without LAA from 20 to 138 hpi (12%, P < 0.02). These survival rates were lower than that of morulae cultured with LAA over a period of 20 to 138 hpi (76%, P < 0.001). The results indicate that cell-free culture of IVM/IVF bovine zygotes in m-SOF supplemented with LAA produces morula-stage embryos relatively tolerant to the process of freezing and thawing.
Hochi
S
S
Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Nagano, Japan.
Kimura
K
K
Hanada
A
A
D000818:Animals; D002417:Cattle; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003470:Culture Media; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D019787:Linoleic Acid / Q000494:pharmacology; D008297:Male; D009028:Morula / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009865:Oocytes / Q000502:physiology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013094:Spermatozoa / Q000502:physiology
D003470:Culture Media; D012710:Serum Albumin, Bovine; D019787:Linoleic Acid