RESUMEN
To improve the efficiency of the production of transgenic cloned goats by somatic cell nuclear transfer (SCNT), the development of reconstructed embryos of first-generation (G1) and second-generation (G2) cloned transgenic goats was compared and analysed. Primary transgenic foetal fibroblasts were used as donor cells for G1 somatic cell nuclear transfer (SCNT). When the G1 transgenic embryos developed to 35 days in the recipient goats, transgenic foetal fibroblasts were isolated from them and used as donor cells for the G2 clone. In the G1 clones, the average fusion rate of reconstructed embryos was 73.62 ± 2.9%, the average development rate (2-4 cells) was 33.96 ± 2.36%, and the pregnancy rate of transplant recipients was 31.91%. In the G2 clones, the average fusion rate of the reconstructed embryos was 90.29 ± 2.03%, the average development rate was 66.46 ± 3.30%, and the pregnancy rate was 58.14%. These results indicate that in the G2 clones, the fusion rate of eggs, the development rate of reconstructed embryos and the pregnancy rate of transplant recipients were significantly higher than those of G1 clones. We believe these results will lay a solid foundation for the efficient production of transgenic cloned animals in the future.
Asunto(s)
Clonación de Organismos , Cabras , Animales , Animales Modificados Genéticamente , Clonación de Organismos/métodos , Clonación de Organismos/veterinaria , Femenino , Fibroblastos , Cabras/genética , Técnicas de Transferencia Nuclear/veterinaria , Óvulo , EmbarazoRESUMEN
Considerable advancements have recently been achieved in porcine somatic cell nuclear transfer (SCNT), but the efficiency remains low. Donor cell size might play an important role in SCNT, but its effects in pigs remain unclear. This study aimed to evaluate the efficiency of porcine SCNT by selecting donor cells of suitable size. Porcine fetal fibroblasts (PFFs) were divided into three groups, group S (small, d ≤ 13 µm), group M (medium, 13 µm
Asunto(s)
Blastocisto , Técnicas de Transferencia Nuclear , Animales , Blastocisto/metabolismo , Tamaño de la Célula , Clonación de Organismos , Embrión de Mamíferos , Desarrollo Embrionario , Femenino , Feto , Fibroblastos/metabolismo , Embarazo , PorcinosRESUMEN
Natural resistance-associated macrophage protein 1 (Nramp1) plays an important role in restraining the growth of intracellular pathogens within macrophages. In this study, Nramp1 cDNA was cloned from Qinchuan cattle and its anti-bacterial activity was demonstrated as being able to significantly inhibit the growth of Salmonella abortusovis and Brucella abortus in macrophages. Calf fibroblasts stably transfected with pSP-NRAMP1-HA vector were used to reconstruct bovine embryos by somatic cell nuclear transfer (SCNT). Reconstructed embryos were maturated in vitro and the blastocyst formation rate (14.0%) was similar to that of control embryos (14.5%). Transgenic blastocysts were transplanted into 43 recipient cattle, of which 14 recipients became pregnant as evidenced by non-return estrus and by rectal palpation. One fetus was aborted after 6½ months of pregnancy and transgene integration was confirmed by semi-quantitative polymerase chain reaction. Together, this study showed that bovine Nramp1 retains biological function against the growth of intracellular bacteria and can be used to reconstruct embryos and produce Nramp1 transgenic cattle, which may benefit the animal and enhance their ability to prevent attack by intracellular pathogens.