Chromosomal Abnormalities and Developmental Kinetics in In Vivo-Developed Cattle Embryos at Days 2 to 5 after Ovulation

• Published in: Biology of reproduction Vol. 65; no. 1; pp. 204 - 208
• Main Authors: VIUFF, Dorthe, HENDRIKSEN, Peter J. M, VOS, Peter L. A. M, DIELEMAN, Steph J, BIBBY, Bo M, GREVE, Torben, HYTTEL, Poul, THOMSEN, Preben D
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01.07.2001
• Subjects: Animals; Biological and medical sciences; Cattle; Chromosome aberrations; Chromosome Aberrations - pathology; Chromosome Disorders; Embryonic and Fetal Development - physiology; Estradiol - metabolism; Female; Fertilization in Vitro; Kinetics; Luteinizing Hormone - metabolism; Medical genetics; Medical sciences; Ovulation - physiology; Ploidies; Progesterone - metabolism; Chromosomal aberration; Embryonic development; Embryo; Ox; Fecundation; Ovulation; In vivo; Vertebrata; Mammalia; Animal; Frequency; Early; Artiodactyla; Ungulata
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod65.1.204

The frequency of chromosome abnormalities was investigated in cattle embryos (n = 256) derived from superovulated heifers (n = 35) on Days 2, 3, 4, and 5 postovulation (PO). Interphase nuclei (n = 4358) were analyzed for chromosome abnormalities using fluorescent in situ hybridization with chromosome 6- and chromosome 7-specific probes and the developmental rate was described by scoring cell numbers. We found that 93%, 85%, 84%, and 69% of the embryos from Days 2, 3, 4, and 5 PO, respectively, displayed a normal diploid chromosome number in all cells. Of the embryos containing abnormal cells, mixoploidy was significantly more frequent than polyploidy. The percentage of mixoploidy at Days 2, 3, 4, and 5 PO was 5%, 13%, 16%, and 31%, respectively, whereas the percentages of polyploidy were 2%, 2%, 0%, and 0%, respectively. The mean number of cells per embryo was 4.7, 8, 11.5, and 48.3, respectively, at Days 2, 3, 4, and 5 PO. Thus, in vivo-developed embryos were significantly more advanced than the in vitro-produced (IVP) embryos except for Day 2. In conclusion, a significantly lower frequency of chromosomally abnormal embryos, in particular displaying polyploidy early after fertilization, was seen in in vivo versus IVP embryos, and these chromosomal abnormalities may be inherent to the process of IVP in cattle.