Cytogenetic analysis of bovine parthenotes after spontaneous activation in vitro.
We conducted a cytogenetic study of bovine parthenotes derived from oocytes matured and cultured in vitro. In vitro maturation was carried out by culturing follicular oocytes for 24 h in TCM199 supplemented with estrous cow serum (ECS) and hormones at 39 degrees C in 5% CO2. Matured oocytes were incubated for 20 h in sperm TALP without the addition of spermatozoa, after which they were cultured in maturation droplets for 48 to 72 h. Spontaneous activation occurred in 9.5% of the matured oocytes. Cytogenetic analysis of 24 parthenotes revealed that 62.5% exhibited a normal, diploid chromosome complement. The remaining 37.5% had various ploidy anomalies: haploidy (25%), triploidy (4.2%) and tetraploidy (8.3%). Parthenotes exhibited different developmental stages. The number of blastomeres ranged from 2 to 8 within a parthenote. Only 1 parthenote was comprised 9 to 16 cells. The results showed that spontaneous parthenogenetic activation which occurs in an IVM/IVF system may interfere with embryo production efficiency.
Lechniak
D
D
Agricultural University of Poznań, Department of Genetics and Animal Breeding, Poland.
Cieślak
D
D
Sosnowski
J
J
D000818:Animals; D001757:Blastomeres / Q000502:physiology*; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D004171:Diploidy; D005260:Female; D008297:Male; D009865:Oocytes / Q000166:cytology* / Q000502:physiology; D009866:Oogenesis / Q000502:physiology*; D010312:Parthenogenesis / Q000235:genetics; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology