Cloning dogs is not an easy task. Researchers in dog cloning face great challenges because of unique conditions that dogs present. For most mammals, oocytes (eggs) are ovulated after maturation is completed in the ovary. However, dogs' oocytes are ovulated when they are immature. Also, in vitro oocyte maturation conditions are very well established in many other animals such as pigs, cows, etc. However, no study has yet been able to successfully mature dog oocytes in vitrowith high efficiency. Therefore, Sooam has established its own protocols for both prediction of ovulation time through measurement of progesterone levels and in vivo oocyte collection.

 

 

Research Topics

 

- Donor Status

Determination of cloning potential and efficiency according to donor breed, size, sex, existence of disease/disease type, living/dead condition at the time of biopsy, etc.

 

- Donor Cell Status

Determination of cloning potential and efficiency according to status of donor cells including: original tissue (e.g. abdominal, oral mucosa, ear fibroblast, reproductive tract, etc.), cryopreservation period, passage number, and morphology and size.

 

- Experiment Procedure

Determination of cloning potential and efficiency according to variables involved in experimental procedures during cloning research including: oocyte collection time depending on progesterone level of oocyte donor, squeezing vs. aspiration method during enucleation, nucleus staining and cytochalasin B treatment, conditions involved in fusion of oocytes and donor cells, in vitro maturation period after fusion, maturation medium components, number of clone embryos used during embryo transfer, oviduct region for embryo transfer, and embryo transfer speed.

 

- Characterization of Cloned Puppy

Examination of traits displayed by cloned puppy including: inheritability of physical (e.g. eye color, fur spot location, etc.) and behavioral traits from donor, causes for possible sex reversal and large offspring syndrome, and reproductive capability.

 

 

Achievements

 

Back in 2005, when the world's first cloned dog Snuppy was born, the pregnancy rate was below 2%. In the last 5 years, through restless efforts of Sooam's researchers, average pregnancy rate during dog cloning has approached nearly 30%. In that period, Sooam has been able to deliver more than 200 cloned puppies. This achievement was possible only through constant optimization efforts by Sooam's researchers and their 24/7 working endeavors. However, we are still not satisfied. We thrive to achieve the pregnancy rate of natural breeding through further optimization of all experimental methods, and we are very optimistic that this goal can be reached very soon.

 

 

Nature: B.C. Lee, M.K. Kim, G. Jang, H.J. Oh, F. Yuda, H.J. Kim, M.H. Shamim, J.J. Kim, S.K. Kang, G. Schattent, W.S. Hwang. Dogs cloned from adult somatic cells. Nature Vol.436 (2005)

 

MRD: S.Kim, S.W. Park, M.S. Hossein, Y.W. Jeong, J.J. Kim, E. Lee, Y.W. Kim, S.H. Hyun, T. Shin, and W.S. Hwang. Production of Cloned Dogs by Decreasing the Interval Between Fusion and Activation During Somatic Cell Nuclear Transfer. Molecular Reproduction & Development 76 (2009): 483-489

 

ARS: M.Sh. Hossein, Y.W. Jeong, S.W. Park, J.J. Kim, E. Lee, K.H. Ko, P. Hyuk, S.S. Hoon, Y.W. Kim, S.H. Hyun, T. Shin, and W.S. Hwang. Birth of Beagle dogs by somatic nuclear transfer. Animal Reproduction Science 114 (2009): 404-414

 

Cellular Reprogramming: M.S. Hossein, Y.W. Jeong, S.W. Park, J.J. Kim, E. Lee, K.H. Ko, H.S. Kim, Y. W. Kim, S.H. Hyun, T. Shin, L. Hawthorne, and W.S. Hwang. Cloning Missy: Obtaining Multiple Offspring of a Specific Canine Genotype by Somatic Cell Nuclear Transfer. Cloning and Stem Cells 11(2009):123-30