The comparison of two embryo donor breeds for the generation of transgenic goats by DNA pronuclear microinjection Vicente J. F. Freitas A,E , Irina A. Serova B , Lyudmila E. Andreeva C , Luciana M. Melo A , Dárcio I. A. Teixeira A , Alexsandra F. Pereira A , Raylene R. Moura A , Edílson S. Lopes-Jr D , Joanna M. G. Souza-Fabjan A , Ribrio I. T. P. Batista A and Oleg L. Serov B A Laboratory of Physiology and Control of Reproduction, Faculty of Veterinary, State University of Ceará, Fortaleza-CE, Brazil. B Institute of Cytology and Genetics, Russian Academy of Sciences, Novosibirsk, Russia. C Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia. D Laboratory of Physiology and Animal Reproduction Biotechnology, Federal University of São Francisco Valley, Petrolina-PE, Brazil. E Corresponding author. Email: vicente.freitas@uece.br Abstract. The aim of the present study was to compare two breeds as embryo donors to produce transgenic goats for the production of human granulocyte colony-stimulating factor. Ten Canindé and 11 Saanen goats were used as donors and received a hormonal treatment for oestrus synchronisation. The superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH-FSH-P1, given in decreasing doses over 3 days. Donors also received 100 mg of GnRH and they were hand-mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after progestagen removal and the pronuclear embryos were microinjected. Fifty-two recipients of undefined breed were prepared by receiving the same oestrus synchronisation treatment; however, only 32 were used due to the availability of embryos. Embryos were surgically transferred into the oviduct. A significant (P < 0.05) difference was observed in the total number of ovulations when Canindé (12.6  6.9) and Saanen (22.5  10.0) donors were compared. Concerning the microinjectable embryos, Canindé goats produced a greater number when compared with Saanen females (P < 0.05). Twenty recipients received 61 Canindé embryos and, of those, 12 kidded, whereas just 12 recipients received 30 Saanen embryos but just three kidded. In total, three transgenic goats were obtained, of which two were healthy Canindé and one stillborn Saanen. It was possible to develop an efficient protocol to obtain transgenic goats for Canindé but not for Saanen breed, for which some variables such as superovulatory regime and time of breeding should be further studied. Additional keywords: Canindé, Saanen, superovulation, transgenesis. Received 22 February 2013, accepted 20 June 2013, published online 20 August 2013 Introduction Portuguese settlers introduced goats to Brazil soon after the discovery in 1500. For over 500 years, European breeds have been naturally selected in semiarid or tropical environments and today present certain attractive characteristics of adaptability such as rusticity and prolificacy (Mariante and Cavalcante 2006). These breeds that have developed in Brazil are known as ‘local’ or ‘naturalised’. From the beginning of the 20th century, commercial breeds (Saanen, Alpine and Toggenburg) have been imported and were used for crossbreeding so as to improve milk production. Even so, they gradually replaced the naturalised breeds in such a way that today some of them are in danger of extinction, as, for example, the Canindé breed (Mariante et al. 2009). One way to increase the interest of breeders by a determined breed, and consequently prevent its extinction, is through the aggregation of economic value to this breed. This can be achieved by the use of the modern biotechnology industry. Many papers have demonstrated that transgenic animals can be used as bioreactors in the production of high-value recombinant proteins in milk, and goats stand out among the several studied species (Ebert et al. 1991; Ko et al. 2000; Huang et al. 2007). The use of goats in biotechnology industry is a reality, especially since the recombinant human antithrombin III (Atryn, GTC Biotherapeutics, Framingham, MA, USA) received marketing approval from the Food and Drug Administration in early 2009 (Lavine 2009). Among the various recombinant proteins that can be produced in the milk of goats, human granulocyte colony-stimulating factor (hG-CSF) is a haematopoietic growth factor that stimulates proliferation and the differentiation of neutrophil precursor cells, and enhances some of the functional properties of CSIRO PUBLISHING Animal Production Science, 2014, 54, 564–568 http://dx.doi.org/10.1071/AN13069 Journal compilation Ó CSIRO 2014 www.publish.csiro.au/journals/an