CYTOGENETIC ANALYSIS OF BOVINE PARTHENOTES AFTER SPONTANEOUS ACTIVATION IN-VITRO

We conducted a cytogenetic study of bovine parthenotes derived from oo cytes matured and cultured in vitro. In vitro maturation was carried o ut by culturing follicular oocytes for 24 h in TCM199 supplemented wit h estrous cow serum (ECS) and hormones at 39 degrees C in 5% CO2. Matu red 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 mature d 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 te traploidy (8.3%). Parthenotes exhibited different developmental stages . The number of blastomeres ranged from 2 to 8 within a parthenote. On ly 1 parthenote was comprised 9 to 16 cells. The results showed that s pontaneous parthenogenetic activation which occurs in an IVM/IVF syste m may interfere with embryo production efficiency. (C) 1998 by Elsevie r Science Inc.