Effects of serum starvation and re-cloning on the efficiency of nuclear transfer using bovine fetal fibroblasts.
The developmental potential of bovine fetal fibroblasts was evaluated using nuclear transfer. Fibroblasts from a 37-day-old fetus were fused to enucleated oocytes before activation. Nuclei of starved (cultured for 8 days in medium containing 0.5% serum) fibroblasts supported the development of reconstructed embryos to the blastocyst stage significantly better than those of non-starved fibroblasts (39% versus 20%; P < 0.05). When nuclear transfer morulae derived from starved or non-starved fibroblasts were used for re-cloning, the proportion of blastocysts (52 and 55%, respectively) obtained with these embryonic nuclei was significantly higher than it was with fibroblast nuclei used in the first round of nuclear transfer (P < 0.05 and P < 0.001, respectively). After transfer of blastocysts derived from non-starved and starved fibroblasts, respectively, 33% (1/3) and 78% (7/9) of recipients were pregnant on day 30 as assessed by ultrasonography. On day 90, the corresponding pregnancy rates were 33% (1/3) and 63% (5/8). Two live male twin calves, derived from non-starved fibroblasts, were delivered by Caesarean section at day 281 of gestation. This study demonstrates a positive effect of serum starvation on the efficiency of nuclear transfer using bovine fetal fibroblasts. The efficiency of nuclear transfer could be further increased by recloning.
Zakhartchenko
V
V
Bavarian Research Centre for Biology of Reproduction (BFZF), Ludwig-Maximilian University, Oberschleissheim, Germany.
Durcova-Hills
G
G
Stojkovic
M
M
Schernthaner
W
W
Prelle
K
K
Steinborn
R
R
Müller
M
M
Brem
G
G
Wolf
E
E
D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002417:Cattle; D002478:Cells, Cultured; D016009:Chi-Square Distribution; D002999:Clone Cells; D005333:Fetus / Q000166:cytology*; D005347:Fibroblasts; D008297:Male; D008856:Microscopy, Fluorescence; D053652:Nuclear Transfer Techniques