Buffalos (Bubalus bubalis) cloned by nuclear transfer of somatic cells

Abstract

Cloning of buffalos (Bubalus bubalis) through nuclear transfer is a potential alternative approach in genetic improvement of buffalos. However, to our knowledge, cloned offspring of buffalos derived from embryonic, fetal, or somatic cells have not yet been reported. Thus, factors affecting the nuclear transfer of buffalo somatic cells were examined, and the possibility of cloning buffalos was explored in the present study. Treatment of buffalo fibroblasts and granulosa cells with aphidicolin plus serum starvation resulted in more cells being arrested at the G0/G1 phase, the proportion of cells with DNA fragmentation being less, and the number of embryos derived from these cells that developed to blastocysts being greater. In addition, a difference was found in the development of embryos reconstructed with fetal fibroblasts from different individuals (P < 0.001). Forty-two blastocysts derived from granulosa cells and fetal fibroblasts were transferred into 21 recipient swamp buffalos, and 4 recipients were confirmed to be pregnant by rectal palpation on Day 60 of gestation. One recipient received two embryos from fetal fibroblasts aborted on Day 300 of gestation and delivered two female premature calves. Three recipients maintained pregnancy to term and delivered three female cloned calves after Days 338-349 of gestation. These results indicate that buffalo embryos derived from either fetal fibroblasts or granulosa cells can develop to the term of gestation and result in newborn calves.