TY  - JOUR
TI  - Nuclear remodelling and early development in cryopreserved, porcine primordial germ cells following nuclear transfer into in vitro-matured oocytes.
AU  - Liu, L
AU  - Moor, R M
AU  - Laurie, S
AU  - Notarianni, E
T2  - The International Journal of Developmental Biology
AB  - Nuclear transfer was conducted in the pig using, as karyoplasts, primordial germ cells which had been cryopreserved. The cytoplasts were presumptive S- or MII-phase, in vitro-matured oocytes, which had been enucleated mechanically. Enucleation was effective in 94.3% of cases. Karyoplasts were introduced into the perivitelline space, in close contact with the cytoplasts, and the complexes fused by electrical stimulation and activation. Activation was successful in 82-88% of nonmanipulated, pulsed oocytes, and in 55% of germ cell-oocyte complexes. The reconstituted embryos were examined for nuclear remodelling and cleavage in vitro. Nuclear swelling was more prominent when MII-phase cytoplasts, rather than S-phase, cytoplasts, were used. After 24 h in culture, the cleavage rate was not significantly different whether blastomeres or primordial germ cells were used as karyoplasts, and whether MII-phase or S-phase cytoplasts were used. However, after 72 h in culture, the developmental rate was higher when MII-phase cytoplasts (75%) were used for the recipients of blastomeres compared with S-phase cytoplasts (38.5%, p < 0.05). Similar tendencies were observed with germ-cell nuclear transfer when inositol was used as medium for electrofusion (60% vs 27.8%, p < 0.05). Furthermore, when MII-phase cytoplasts were used, the nuclear transferred embryos derived from blastomeres developed at a significantly higher rate than from primordial germ cells (37.5%, p < 0.05). We conclude that cryopreserved primordial germ cells are competent to undergo nuclear remodelling and cleavage during 72 h or incubation in vitro to the 4-cell stage, following nuclear transfer to enucleated, activated (S-) or MII-phase oocytes. This experimental system may help to elucidate events in the early development of pig embryo following nuclear transfer using germ cells as karyoplasts.
PY  - 1995
VL  - 39
IS  - 4
SP  - 639
EP  - 644
J2  - Int. J. Dev. Biol.
LA  - en
SN  - 0214-6282
SN  - 1696-3547
UR  - https://ijdb.ehu.eus/article/8619962
Y2  - 2024/12/22/17:46:01
ER  -