Effect of cell-free synchronous uterine flushings and microsurgery on the development of porcine embryos in vitro.
Experiment I was designed to determine if cell-free synchronous uterine flushings contain an embryotoxic substance that is normally screened by the intact zona pellucida. Sixty 4-cell embryos were allocated to three treatment groups: 1) control embryos (n = 20) were cultured in Modified Kreb's Ringer Bicarbonate medium + 10% bovine calf serum (mKRB-BCS), 2) UF embryos (n = 20) were cultured in 80% mKRB-BCS + 20% sterile dialyzed uterine flushings (UF), 3) MicroUF embryos (n = 20) received a microsurgical incision in the zona pellucida and were cultured in 80% mKRB-BCS + 20% UF. Following 72 h in culture at 37 degrees C under a 90% N2, 5% CO2, and 5% O2 atmosphere, the number of nuclei/embryo and the incidence of protrusion of the trophoblast through the zona pellucida (PTZ) were recorded. Addition of UF had no effect on embryo development. A greater (P less than .005) proportion of MicroUF embryos exhibited PTZ as compared to UF and control embryos. Experiment II was devised to further characterize the occurrence of PTZ in Micro porcine embryos. Thirty-three 4- to 10-cell embryos and 14 morulae were distributed across two treatments: 1) control embryos (n = 16 and 6, respectively) were cultured as described in Experiment I; and 2) micro embryos were treated similarly to MicroUF embryos in Experiment I but were cultured in mKRB-BCS only. At the onset of PTZ, embryos were immediately fixed and examined. The proportion of embryos exhibiting PTZ was greater (P less than .007) for Micro versus control embryos.(ABSTRACT TRUNCATED AT 250 WORDS)
Martin
M J
MJ
Department of Animal Sciences, University of Missouri, Columbia 65211.
Cantley
T C
TC
Flowers
W L
WL
Day
B N
BN
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002478:Cells, Cultured; D005314:Embryonic and Fetal Development; D005260:Female; D009028:Morula / Q000502:physiology; D013552:Swine / Q000196:embryology*; D014327:Trophoblasts / Q000502:physiology*; D014599:Uterus / Q000737:chemistry*; D015044:Zona Pellucida / Q000502:physiology*