Relationship between dead cells and DNA fragmentation in bovine embryos produced in vitro and stored at 4°C

Abstract

DNA fragmentation and its relationship with dead cells were examined in bovine blastocysts produced in vitro and stored at 4 degrees C for 1-5 days. Survival and development to the hatching and hatched blastocyst stage decreased with increasing storage time. Both were significantly lower at 72 hr than at 48 hr. None of the embryos stored for 120 hr developed to the hatching or hatched blastocyst stage. The proportion of dead cells per embryo increased progressively as the time of storage increased, until 69% of embryonic cells were dead after 120 hr of storage. There was no significant difference between the proportions of DNA fragmentation per embryo stored for 0 and 24 hr (12% vs 16%). However, the proportion of DNA fragmentation in embryos stored for longer than 48 hr was significantly greater than that in embryos stored for less than 24 hr. There were no significant differences among those stored for longer than 48 hr (28-33%). These results suggest that the reduced developmental competence of bovine embryos stored at 4 degrees C is characterized by necrotic change rather than apoptotic change.

The in vitro culture supplements and selected aspects of canine oocytes maturation

“…There are several reports indicating the role of media in vitro supplements on the meiotic maturation competence of canine oocytes (Otoi T et al 1999, Rodrigues and Rodrigues 2003, Cui et al 2006). However, the in vitro maturation procedures still bring low efficiency and only 15-20% of bitch oocytes reach the MII stage.…”

Effects of Exposure to Zearalenone on Porcine Oocytes and Sperm During Maturation and Fertilization In Vitro

“…The denuded oocytes in each group were analyzed in terms of DNA damage and nuclear status by using a combination of nuclear staining and TUNEL by a modified version of procedures described previously [20]. Briefly, the oocytes were fixed overnight at 4 C in 3.7% (w/ v) paraformaldehyde diluted in PBS.…”

Early transcription from the maternal genome controlling blastomere integrity in mouse two-cell-stage embryos

“…Among the cellular and molecular indicators of early cell death are nuclear fragmentation, blastomere cytofragmentation, DNA fragmentation, caspase activation, and annexin V exteriorization, all of which are classical hallmarks of the well-regulated process known as apoptosis (3,7,20,26,27,30,33,39,50). In contrast to somatic cells, however, early embryos may not display all of these hallmarks concurrently (21,60).…”

“…Oocyte or blastomere fragmentation is seen in a number of different mammalian species, including cow, mouse, and human (2,3,7,20,33,39,57). Clinically, this reduces the number of high-quality embryos available for establishing pregnancy.…”