Influence of oocyte donor and embryo recipient conditions on cloning efficiency in dogs

Species‐specific Challenges in Dog Cloning

“…In previous work, the day of ovulation was considered to be when serum progesterone concentration reached 4.0–9.9 ng/ml and the optimal time for oocyte recovery was planned as 70–76 h after ovulation (Kim et al. ).…”

“…Synchrony (same day ovulation) and advanced synchrony (oocyte donor ovulated 1 day earlier than recipient) showed higher pregnancy and delivery rates than retarded asynchrony (oocyte donor ovulated 1 day later than recipient) (Kim et al. ). The parity of recipient can affect cloning efficiency, with nulliparous recipients associated with higher delivery rate (3.0% vs 1.7%, p < 0.05) than multiparous recipients (Kim et al.…”

“…The parity of recipient can affect cloning efficiency, with nulliparous recipients associated with higher delivery rate (3.0% vs 1.7%, p < 0.05) than multiparous recipients (Kim et al. ). Therefore, we recommend the use of naturally synchronous, nulliparous dogs as recipients.…”

Ectopic liver and gallbladder in a cloned dog: Possible nonheritable anomaly

“…Recovery of in vivo-matured oocytes, SCNT, and embryo transfer were done on the basis of a previous report [30,35]. In brief, surgical oviduct flushing was performed 72 hours after serum progesterone reached 5 to 10 mg/mL [36], and cumulus cells of matured oocytes were removed by repeated pipetting in 0.1% (wt/vol) hyaluronidase in TCM-199.…”

Production of offspring from cloned transgenic RFP female dogs and stable generational transmission of the RFP gene

“…While many previous studies attempted to optimize this technique in canids (Jang et al, 2008;Kim et al, 2010;Lee et al, 2005;Oh et al, 2009), SCNT efficiency in dogs remains very low as the underlying mechanisms of reprogramming somatic cells are still unclear . This low efficiency is in line with other species (around 1-5%) (Yang et al, 2007).…”