| We developed a chemically defined medium (porcine zygote medium: PZM).
Our novel PZM based on the composition of pig oviduct fluid is efficient
for in vitro culture (IVC) of porcine zygotes. Moreover, we also attempted
to establish a chemically defined system for in vitro fertilization (IVF)
of porcine in vitro-matured oocytes using PZM as a basal medium. The presence
of specific doses of theophylline, adenosine and cysteine during IVF improved
the fertilizing ability of porcine oocytes and frozen-thawed spermatozoa
or the subsequent embryo development under the chemically defined conditions
of culture. Normal piglets were obtained from in vitro-produced blastocysts
by embryo transfer into recipients. The results clearly demonstrate that
porcine blastocysts can be produced by IVF and IVC in chemically defined
media and that they have full-term developmental potential. (Theriogenology
Section, Department of Production Diseases TEL +81-29-838-7784) |