The present experiment was conducted to
clone swamp buffalo and cattle embryos using in
vitro matured swamp buffalo oocytes as recipient
cytoplasts and swamp buffalo and cattle ear fibroblast
cells (BEFC and CEFC) as donor nuclei and
examine the use of mouse fetal fibroblast cell as
co-culture cell during embryos development. Swamp
buffalo ovaries were collected from slaughterhouse
and cumulus oocyte complexes (COCs) were
harvested by aspiration and then in vitro matured
for 19-20 h. Matured oocytes were enucleated by
micromanipulation under an inverted microscope.
Enucleation was confirmed by staining the removed
portion with Hoechst 33342. Individual donor cells
of swamp buffalo or cattle ear fibroblast cells
(diameter 14-16 μm) were inserted into perivitelline
space of recipient cytoplasts by micromanipulation.
The couplets were fused with two DC pulses of 30
V/couplet for 15 μsec each time in fusion medium.
After fusion, reconstructed embryos were immediately
activated with A23187 followed by culturing in
SOFaa-10 which containing cycloheximide and
cytochalasin D for 5 h, then cultured in SOFaa
supplemented with 1% FCS (SOFaa-1) for 2 days.
The embryos at 8-cell stage were harvested and
assigned to co-cultured with frozen-thawed buffalo
oviductal epithelial cell (BOEC) or mouse embryonic
fibroblast cell(MEFC) for another 2 days then
replaced twice with SOFaa-10 every 2 days. The
result from the experiment demonstrated that the
embryos reconstructed by both BEFC and CEFC
could developed nearly the same rate to 8 cell (53.1
vs 51.0 %), morula(19.8 vs 17.0 %), and blastocyst
stage(15.6 vs 13.9 %) when co-culture with BOEC.
While MEFC could support the reconstructed
embryos developed to morula at the same rate (10.8
%) and very low rate to blastocyst stage (2.8 vs 1.3
%). The cloned cattle embryos could be produced
using swamp buffalo oocytes as recipient cytoplasts
and co-culture with MEFC could support the
development but not as good as BOEC. The
development of the cloned cattle embryos in the
recipient cows will be further studied.