Cloned horse pregnancies produced using adult cumulus cells.

The research indicates an attempt to clone horses using adult cumulus cells. The experiment studied if the origin of these cells from different mares had an impact on the cloning success. Despite some early pregnancy detections, all cloned embryos were lost, pointing at challenges that need further research on this subject.

Research Method and Objectives

• The study aimed at verifying the potential of cloning horses using adult cumulus cells, the clustering cells surrounding oocytes or female sex cells.
• The study also strived to examine the influence of the cell donor on the cloning process.

Data Collection

• The researchers extracted in-vivo matured cumulus-oocyte complexes from mares using a transvaginal ultrasound-guided follicle aspiration process.
• They used the extracted oocytes as cytoplasts and the cumulus cells from different mares as donor cells.
• Following the procedure of nuclear transfer and activation, they transferred the cloned embryos to the oviduct of recipient mares that had ovulated within the past 24 hours.

Study Outcome

• Out of 136 follicles aspirated from 96 mares, they managed to recover 72 oocytes.
• After the transfer of 62 cloned embryos to recipients, seven early pregnancies were detected using ultrasound between Day 14 and 16, indicating an 11.3% success rate.
• Disappointingly, all these pregnancies were later spontaneously lost between Days 16 and 80, indicating a setback in the cloning experiment.
• As observed, cumulus cells derived from Mare 160 appeared to result in a higher embryo survival rate than cells drived from Mare 221, though the difference was not statistically significant.
• This research, according to the researchers, is the first to document the establishment of cloned horse pregnancies derived from adult cumulus cells.