Research Article

Post-thaw culture in presence of insulin-like growth factor I improves the quality of cattle cryopreserved embryos

Alexander V. Makarevich^a1 c1, Elena Kubovičová^a2, Zdena Hegedušová^a2a3, Juraj Pivko^a2 and František Louda^a2

^a1 Institute for Cattle Breeding Ltd Rapotin, Vyzkumniku 267, 788 13 Vikyrovice, Czech Republic

^a2 Institute for Cattle Breeding Ltd Rapotin, Vyzkumniku 267, 788 13 Vikyrovice, Czech Republic

^a3 AgriResearch Rapotin Ltd, Vyzkumniku 267, 788 13 Vikyrovice, Czech Republic

Summary

The goal of this study was to examine the effect of insulin-like growth factor I (IGF-I; added during post-thaw culture (48 h)) on the preimplantation viability and quality of cryopreserved bovine in vivo recovered embryos. The morula stage embryos, non-surgically recovered from superovulated dairy cows of Czech Fleckvieh cattle breed, had previously been cryopreserved by a slow freezing technique and stored in liquid nitrogen since 1989–1990. Following thawing, the embryos were cultured for 48 h either alone (no IGF-I) or in the presence of IGF-I (10 or 100 ng/ml); non-cultured embryos served as a control. Thereafter, the embryos were analyzed for cleavage to the blastocyst stage, apoptosis (TUNEL), embryo cell number and quality of actin cytoskeleton. Following post-thaw culture 41% of embryos developed to advanced blastocysts. IGF-I increased this per cent and, at a higher dose, essentially reduced the per cent of degenerated embryos. In cultured embryos, IGF-I at both doses elevated the cell number compared with non-cultured embryos. However, in comparison with embryos cultured without IGF-I, only the higher IGF-I dose resulted in elevating the embryo cell number. The TUNEL index was significantly lowered by IGF-I treatment. Thawed embryos were mostly of the grade III actin type and fewer (12%) had grade II actin, whilst no grade I actin embryos were noted. The addition of IGF-I resulted in the appearance of grade I actin embryos (8.33 and 6.9% for 10 and 100 ng/ml, respectively). These observations indicate that the addition of IGF-I during post-thaw culture can improve the quality of bovine cryopreserved embryos.

(Received July 05 2010)

(Accepted September 29 2010)

(Online publication February 08 2011)

Keywords:

• Cattle;
• Embryo;
• IGF-I;
• Post-thaw quality

Correspondence:

^c1 All correspondence to: Alexander V. Makarevich. Institute for Cattle Breeding Ltd Rapotin, Vyzkumniku 267, 788 13 Vikyrovice, Czech Republic. Tel.: +421 37 6546 334. Fax: +421 37 6546 480. e-mail: makarevic@cvzv.sk