Reprod. Nutr. Dev. 43 (2003) 487-496
DOI: 10.1051/rnd:2004007

Macromolecular source as dependent on osmotic pressure and water source: effects on bovine in vitro embryo development and quality

Paloma Duque^{a, b}, Carlos O. Hidalgo^a, Enrique Gómez^a, Belén Pintado^c, Nieves Facal^a and Carmen Díez<sup>a

a</sup>  Área de Genética y Reproducción, SERIDA, Camino de los Claveles 604, Somió, 33203 Gijón, Asturias, Spain
^b  Centro de Fertilización in vitro de Asturias, C/ Alvarez Garaya 12, 33206, Gijón, Spain
^c  Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, INIA, Ctra. de la Coruña, Km 5,9, 28040, Madrid, Spain

Received 22 April 2003; accepted 11 September 2003

Abstract - This study evaluated the protective effect of protein, as dependent on osmolarity, and the quality of water sources used to prepare embryo culture media. In Experiment 1, two concentrations of NaCl were used to obtain culture media with normal (280 mOSM) and low (245 mOSM) osmolarity, each supplemented with either bovine serum albumin (BSA) or polyvinyl alcohol (PVA). Low osmolarity improved blastocyst rates in the presence of BSA ( P < 0.01) and tended to do it in medium containing PVA ( P < 0.07). Furthermore, low osmolarity allowed PVA to increase inner cell mass (ICM) numbers and ICM/total cell rate ( P < 0.05), while trophectoderm (TE) and total cell counts tended to decrease ( P < 0.08). In Experiment 2, culture media were prepared with two water sources (Milli-Q and Sigma-W3500-) in combination with BSA or PVA. Both water sources yielded similar embryo development rates, but in the presence of BSA, Milli-Q water produced embryos with increased ICM/total cells rates ( P < 0.05). On the contrary, Sigma water tended to increase trophectoderm cell counts ( P < 0.08). In conclusion, the present study showed that low osmolarity is beneficial to embryo development and combinations of macromolecule and osmolarity influence trophectoderm differentiation. Both Milli-Q and Sigma supported embryo development at comparable rates, although in the presence of BSA, blastocysts obtained in the medium prepared with Milli-Q water had superior quality in terms of ICM/total cells rates.

Key words: in vitro produced bovine embryo / osmolarity / water quality / protein / cell number

Corresponding author: Carmen Díez mcdiez@serida.org

© INRA, EDP Sciences 2003