Observations on the fertilization and development of preimplantation bovine embryos in vitro in the presence of Tritrichomonas foetus
- 作者：Bielanski ; A. ; Ghazi ; D.F. ; Phipps-Toodd ; B.
- 关键词：Tritrichomonas foetus ; Embryo ; Semen ; Fertilization ; Zona pellucida
- 刊名：Theriogenology
- 出版年：2004
- 期刊代码：98_0093691x
- 类别：abs
- 出版时间：April 1, 2004
- 卷：61
- 期：5
- 页码：821-829
- 文件大小：277 K
摘要
Tritrichomonas foetus, a world-wide distributed parasitic protozoan is a cause of infertility and abortion. There is no documented information on the susceptibility of bovine embryos to the parasite. To determine the effect of T. foetus on fertilization and embryonic development of preimplantation bovine embryos, we added approximately 104/ml or 106/ml T. foetus (Belfast strain) to sperm cells and oocytes prior to in vitro fertilization (IVF) or to presumptive zygotes 24h post-fertilization. Light and scanning electron microscopy (SEM) revealed that exposure of oocytes or embryos at any stage of development to T. foetus caused rapid adhesion of the trichomonads to the embryonic intact zona pellucida (ZP) and to trophoblastic cells of hatched blastocysts. Treatment of contaminated embryos with 0.25%trypsin for 3min did not render them free from T. foetus. Motile parasites were not observed after 18h incubation in IVF medium, or after 72h in synthetic oviductal fluid (SOF) embryo culture medium. The percentages of cleaved zygotes, blastocysts and hatched embryos resulting from culture of experimental and uninfected control groups of embryos were not different (P>0.05). Tritrichomonas foetus was not detected in embryonic cells of ZP-intact or hatched embryos when examined by transmission electron microscopy (TEM). In conclusion, T. foetus has no detrimental effect on the fertilization and development of IVF embryos and the potential risk of transmission of trichomonosis is unlikely, due to the limited survival of the parasite in IVF culture conditions.