02822naa a2200157 a 450000100080000000500110000800800410001910000110006024500700007126000090014152022940015065300230244465300220246765300250248977301500251410812172011-10-11       2011    bl uuuu     u00u1 u    #d1 aEpagri  aPrenancy of cloned embryos a freemartin cow and endangered breed.  c2011  aThe Rouge Flamand (Flemish) cattle were introduced into Brazil in 1945. As a dual-purpose breed, it had easily adapted to the regional climate conditions and several herds of Rouge Flamand cattle were established. However, during the last years the number of herds has been considerably reduced due to specialized breeds import. There are about fifty remaining animals at the experimental station Epagri (Empresa de Pesquisa Agropecuária e Extensão Rural do Estado de Santa Catarina) located in Lages, Santa Catarina, but they are threatened with extinction due to imminent lack of genetic variability. One of these remaining animals is a freemartin cow, which is about 17 years old and extremely well-conformed, though infertile. Over the last years, a number of animals of different species have been produced by somatic cell nuclear transfer (SCNT) for different purposes. The main objective in this work is to use SCNT to rescue the genotype of a Rouge Flamand freemartin cow and produce a fertile animal. Somatic cells were obtained from an ear skin biopsy through the explantation technique. Up to the third passage and after obtaining at least 90% confluence, cells were cryopreserved in 0.25mL straws in DMEM + 10% fetal calf serum and 10% DMSO. The handmade cloning steps were performed according to Mezzalira et al. (2011, Cell. Reprog, 13, 65-76). Cleavage and blastocyst rates were respectively 87% (204/233) and 34% (80/233). Recipient cows of tricross European breeds were used as recipient females at day seven after estrus and D8 blastocysts were transferred. Part of the SCNT blastocysts were vitrified/thawed according to Mezzalira et al. (2010, Reprod. Fert. Dev, 22, 210). The remaining blastocysts were maintained fresh and were transferred in pairs to each recipient. From the six recipient cows that received fresh embryos, 6 (100%) established pregnancy; 3 (50%) were pregnant up to 60 days and 2 (33%) are still pregnant at 80 and 180 days. Vitrified/thawed embryos were transferred to two recipient cows, which were both confirmed pregnant but embryos died by day 45 after transfer. For the first time, this study shows that SCNT embryos derived from a freemartin animal can develop into blastocyst and establish pregnancies after it transfer to recipient cows.  aCell reprogramming  aFreemartin cattle  aGenetic biodiversity  tIn: REUNIÃO ANUAL DA SOCIEDADE BRASILEIRA DE TECNOLOGIA DE EMBRIÕES, 25., 2011, Cumbuco, CE. [Anais...]. Porto Alegre, RS: UFRGS, 2011. p. 444.