• Proceedings of the Korean Society of Developmental Biology Conference
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• 2009.02a
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• pp.49-57
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• 2009

The cloning of canids was succeeded in 2005, several years after the birth of Dolly the sheep and also after the cloning of numerous other laboratory and farm animal species. The delay of successful somatic cell nuclear transfer (SCNT)was due to the unique reproductive characteristics of the female dogin comparison to other domestic mammals, such as ovulation of immature canine oocyte and a requirement of 25 days for the completion of meiosis within the oviduct (Holst & Phemister, 1971). When the technology for the recovery of in vivo matured oocyte was established, the application of cloning also became possible and cloned dog offspring were obtained. This report summarizes the progress of technical procedures that are required for cloning canids and the application of this technique. The first cloned dog, Snuppy, was achieved using an in vivo-matured oocyte which was enucleated and transferred with an adult skin cell of male Afghan hound. After establishment of a criterion of well-matured oocyte for the improvement of SCNT efficiency, we obtained three cloned female Afghan hound and a toy poodle cloned from 14 year-old aged Poodle using SCNT through this factor. To date, cloned dogs appeared to be normal and those that have reached puberty have been confirmed to be fertile. Through application of canine SCNT technique, first, we demonstrated that SNCT is useful for conserving the breed of endangered animal from extinction through cloning of endangered gray wolves using inter-species SCNT and keeping the pure pedigree through the cloning of Sapsaree, a Korean natural monument. Secondly, we showed possibility of human disease model cloned dog and transgenic cloned dog production through cloning of red fluorescent protein expressing dog. Finally, SCNT can be used for the propagation of valuable genotypes for making elite seed stock and pet dog. In summary, dog cloning is a reproducible technique that offers the opportunity to preserve valuable genetics and a potential step towards the production of gene targeted transgenic cloned dogs for the study of human diseases.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.122-122
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• 2003

This study examined the viability of canine oocytes following storage at 4 or $38{\circ}C$ for 5 hrs. The ovaries were collected from domestic dog following ovariohysterectomy at a local veterinary clinics and transported to laboratory In two different transport temperature at 4 or $38{\circ}C$ within 5 hrs. The cumulus oocyte complexes (COCs) were recovered after slicing with blade. In Exp. 1, the oocytes collected were matured in DMEM supplemented with l0% FBS, 0.6 mM/mlcysteine, 0.2 mM Pyruvic acid, 20 ng/ml $E_2$ and 1 $\mu g/ml$ rbST at humidified atmosphere containing 5% $CO_2 38{\circ}C$ for 24 or 48 hrs to analysis of survivability. In Exp 2, to assess nuclear development at 38{\circ}C$ group, the oocytes were matured in maturation medium for 24, 48 or 96 hrs. Survivability was judged by a morphological appearance and PI staining. Survivability rates were analyzed by General Linear Models procedure in SAS. The survival rates at 4{\circ}C$ ovary transport group showed significantly lower than at 38{\circ}C$ group (0 vs 72.9% in 48 hrs and 13.2 vs 77 8% in 24 hrs; P<0.05). The nuclear development of oocytes to MI to MII stages at 24, 48 and 96 hrs was 8.3% (6/72), 8.9% (9/101), and 9.5% (8/84). These results showed that the canine oocytes were remarkably sensitive to a low temperature and did not increase nuclear development rate depend on maturation time to 96 hrs.

• Journal of Embryo Transfer
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• v.18 no.2
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• pp.85-90
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• 2003

This study examined the viability of canine oocytes following storage at 4 or 38$^{\circ}C$ for 5 h. Cumulus intact oocytes were collected from domestic dog following ovariohysterectomy at local veterinary clinics. In Exp I, the oocytes that collected from ovary transport different temperatures (4 or 38$^{\circ}C$) for 5 h, were cultured for (24 or 48 h). Survivability of oocytes judged by morphological appearance and PI (propidium iodide) staining. The survival rates at 4$^{\circ}C$ ovary transport group showed significantly lower than control group (0%; 0/129 vs. 72.9%; 129/177) 48 h after culture (P<0.05). In Exp II, to assess nuclear maturation of control group oocytes (ovary transported at 38$^{\circ}C$) after in vitro cultured for 24, 48 or 96 h. After 24 h and 48 h of culture, the metaphase I to metaphase II stages (MI to MII) was 8.3% (6/72) and 8.9% (9/101), and which was not increased at 96h (9.5%; 8/84). These results show that canine oocytes remarkably sensitive to low temperature and the percentage of oocytes reaching MI to MII did not increase 96 h after culture.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.145-151
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• 2002

The aim of these experiments was to investigate in vitro nuclear maturation of canine oocyte collected from various stages of estrus cycles, Ovaries were obtained from 1 to 4 year-old mongrel bitch and minced for oocyte collection in phosphate buffered saline with 100 iu penicillin-G $m\ell$／sup -1／, 50 $\mu\textrm{g}$ streptomycin sulphate $m\ell$／sup -1／ and 0.1％ (w／v) polyvinyl alcohol. Cumulus-oocyte-complexes (COCs) were washed in HEPES buffered tissue culture medium (TCM)199 and in vitro matured in TCM-199 culture medium supplemented with sodium pyruvate 0.028mg/$m\ell$, L-glutamine 0.146mg／$m\ell$, penicillin G 10,000 IU／$m\ell$, streptomycin 0.031mg／$m\ell$ and 10％ (v／v) fatal calf serum. COCs were in vitro matured for 48～72 hrs at 39$^{\circ}C$ in humidified 5％ $CO_2$ in air atmosphere. In vitro matured oocytes were remove the cumulus cells using 0.2％ (v／v) hyaluronidase. After denuding, oocyte were placed in acetic acid : methanol : chlorform solusion (3:6 : 1.5 v／v) for 30 sec and acetic acid: ethanol(1:3 v／v) for 48hrs fixation. Nuclear maturation was classified to GV, GVBD, MI, MII and degenerate oocyte under microscopy after 1％ aceto-orcein stain. In vitro maturation rates at 48hrs were not significantly difference among the oocytes collected from different stage of estrus at 15.9％, 16.3％, 23.7％ and 18.2％ for anestrus, proestrus, estrus and diestrus. However, the oocytes maturation(36.6％) of collected from estrus ovaries were significantly different from oocytes derived from proesturs, diestrus and anestrus ovaries(30.8％, 17.5％ and 22.1％; p＜0.05). The overall in vitro maturation rates were significantly higher (p＜0.05) in 72hrs culture than 48hrs culture system. In summary, there was a tendency for higher in vitro maturation rates with the oocyte collected from estrus ovary than other stages of estrus. Also, for nuclear maturation, in vitro culture of oocyte for 72hrs was better than 48hrs culture.

• Journal of Veterinary Science
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• v.19 no.6
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• pp.725-734
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• 2018

Ovaries of 21 bitches presented with gynecopathies were surgically removed and histologically examined. Standard histological, as well as immunohistochemical, classification of 193 cystic structures resulted in the classification of 72 cysts of subsurface epithelial structures (SES), 61 follicular cysts (FCs), 38 cystic rete ovarii (CRO), 13 lutein cysts (LCs), and 9 non-classifiable cysts (NCCs). In addition to the histological classification, results were interpreted according to subject medical history, clinical examination outcome, and macroscopic observations during ovariohysterectomy. Dogs with ovarian cysts (OCs) and associated reproductive perturbations were mostly nulliparous, of large breed, and had an average of $9.5{\pm}3$ years. Prolonged or shortened inter-estrus intervals of past heats, however, seemed to be relatively low-risk factors for the development of OCs in dogs. Furthermore, we provide histological observations of a rarely seen canine LC including a degenerated oocyte in the central cavity.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.7-13
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• 2007

The present study investigated the effects of follicle stimulating hormone (FSH) and human chorionic gona-dotrophin (hCG) on the nuclear maturation of canine oocytes. Oocytes were recovered from mongrel female ovaries in various reproductive states; follicular, luteal or anestrous stage. Oocytes were cultured in sserum-free tissue culture medium (TCM)-199 supplemented with various concentrations of FSH (Exp. 1: 0, 0.5, 1.0 or 10 IU) or hCG (Exp.2:0, 0.5, 1.0 or 10 IU) or both (Exp. 3:1 IU FSH +1 IU hCG) for 72 hr to determine the effective concentration of these hormones, and to examine their combined effect. After maturation culture, oocytes were denuded in PBS containing 0.1% (w/v) hyaluronidase by gentle pipetting. The denuded oocytes were stained with $1.9\;{\mu}M$. Hoechst 33342 in glycerol and the nuclear state of oocytes was evaluated under UV light. More (p<0.05) oocytes matured to MII stage when follicular stage oocytes were supplemented with 1 IU FSH (6.2%) compared with the control, 0.1 or 10.0 IU FSH (0 to 1.2%). Significantly higher (p<0.05) maturation rate to MII stage was observed in follicular stage oocytes supplemented with 1.0 IU hCG (7.2%) compared with the control or other hCG supplemented groups (0 to 1.5%). However, the combination of FSH and hCG did not improve the nuclear maturation rate of canine oocyte (2.4 %) compared with FSH (6.2%) and hCG alone (7.2%). In conclusion, FSH or hCG alone significantly increased the maturation of canine oocytes to MII stage.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.123-123
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• 2003

This study was conducted to determine the ability of nuclear development of canine oocytes depend on the kind of maturation media and addition of serum sources. Ovaries were collected from a bitches at various stages of estrus cycle by an ovariohysterectomy. Oocytes were collected of cumulus oocytes complexes after slicing of ovaries with blade. The maturation medium was containing 0.6 mM/ml cysteine, 0.2 mM pyruvic acid, 20 ng/ml $E_2$ and 1 $\mu g/ml$ rbST Exp. 1, the oocytes were matured in four different maturation medium as follows: 1) TCM-199, 2) DMEM, 3) NCSU37 and 4) modified-NCSU37 with 10% FBS. Exp. 2: the oocytes were matured in mNCSU37 supplemented with different protein sources (10% FBS, 10% EDS, 0.3% BSA and 0.1% PVA) to select the optimal one. Oocytes were matured in a humidified atmosphere containing 5% $CO_2$ at $39{\circ}C$ for 72 hrs. The maturation rate were analyzed by Duncan's multiple range test using General Linear Models procedure in SAS. The rates of meiotic resumption to MI-MII depend on different culture media were achieved with TCM-199 (5.2%), DMEM (5.0%), NCSU37 (7.2%) and m-NCSU37 (5.9%), respectively. The rates of meiotic resumption to MI-MII according to addition of protein source were 10% FBS (13.3%), 10% EDS (25.0%), 0.3% BSA (25.0%) and 0.1% PVA (15.4%), respectively. In conclusion, the results obtained showed that in vitro maturation media and protein supplement to m-NCSU37 culture medium tested did not promote the final steps of IVM in canine oocytes.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.147-153
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• 2004

본 실험에서는 수술적 방법을 이용하여 난관 절제술을 실시한 성숙 난자의 회수율과 카데터를 이용한 난자 회수율 그리고 새롭게 고안된 개 난자 회수용 니들을 이용한 회수율을 비교하였으며, 각각의 회수 방법이 성숙난자의 외형에 미치는 영향을 조사한 결과는 12두에서 난관절제술로 채취한 성숙난자의 회수율은 89.7% 이었다. 수술적 회수방법에서는 본 연구실에서 개발한 난자 회수용 니들을 난관내에 삽입-결찰한 후 난관-자궁 접합부에서 난자 회수용 배지를 관류하는 방법으로 평균 83.0%의 회수율을 얻었다. 이 같은 결과는 TomCat 카테터를 이용한 회수율 (68.9%)과 난자 회수용 니들을 결찰하지 않고 관류한 방법 (73.5%) 보다 유의적으로 높은 회수율을 나타내었다 (p<0.05). 또한 난관 절제술과 각각의 수술적 방법으로 회수한 난자의 형태학적 차이는 관찰할 수 없었으나 난관 절제술과 난자회수용 니들을 결찰하여 회수한 난자의 형태와 난질이 Tom Cat 카테터나 결찰하지 않은 니들을 이용하였을 때보다 영향을 덜 받는 경향을 나타내었다 (각각 72.0%, 73.8%와 62.8%, 69.6%).

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.117-121
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• 2002

This study was carried out to investigate the in vitro fertilization rate of canine immature oocytes cryopreserved by vitrification freezing. The vitrification solutions of EPS and EDS were consisted of 40％ ethylene glycol 18％ Ficoll and 0.3M sucrose, and 20％ ethylene glycol, 16.5％ DMSO and 0.5M sucrose in TCM-199 medium supplemented with 10％ FCS, respectively. The oocytes were exposed The developmental rate of in vitro cultured oocytes recovered from ovaries collected at different stages of the reproductive cycle were 3.8％, 10.7％, 46％, respectively. to EFS or EDS at $25^{\circ}C$ and loaded into straw fer 30 sec. The straws was slowly immersed into L$N_2$. Fertilization and survival rate was defined as development rate on in vitro culture or FDA-test. 1. The fertilization rate after vitrification freezing of immature oocytes at 1, 6, 12 and 24 hrs after collection from ovaries was very low(5.3％～31.4％) than the unfrozen oocyte(60.0％). And the fertilization rate after vitrification freezing of immature oocytes was very higher than that of mature oocytes. 2. The survival rate after vitrification freezing of immature oocytes at 1, 6, 12 and 24 hrs after collection from ovaries was 55.0％, 40.0％, 28.6％ and 17.1％, respectively. And the survival rate after vitrification freezing of immature oocytes was slightly higher than that of mature oocytes.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.93-100
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• 2001

This study was conducted to evaluate the nuclear development of preantral follicle oocytes in dog following collecting from different estrus ovaries and oocyte diameter. To do this, ovaries were collected from Sunchon livestock station by ovarioectomy and then transported to laboratory in 3$0^{\circ}C$ saline within 2 h. All of the ovaries were washed three times with saline supplemented with 100 IU Penicillin and 100 $\mu\textrm{g}$/$m\ell$ Streptomycin and then sliced with blade in 100 mm dish. All of the oocytes collected were classified the oocyte size such as over 110 ${\mu}{\textrm}{m}$ or under 110 ${\mu}{\textrm}{m}$ and the estrus status. To induce the nuclear development, oocytes were cultured in TCM199 $\alpha$-MEM supplemented with 10% FCS, 0.1 $\mu\textrm{g}$/$m\ell$ sodium pyruvate, 100 ng/$m\ell$ FSH, 100 ng/$m\ell$ EGF, 1% ITS, 100 IU/$m\ell$ penicillin, 100 $\mu\textrm{g}$/$m\ell$ streptomycin at 38.5$^{\circ}C$, 5% $CO_2$ incubator for 72 h. After culture, all of the oocytes were stained in 1% orcein following fixed in 45% Acetic acid for 48 h. The oocyte recovery rates of over 110 ${\mu}{\textrm}{m}$ from estrus ovary (63.6%) were significantly higher rather than that in anestrus status (51.5%). Oocyte recovery rate per ovary of over 110 ${\mu}{\textrm}{m}$ in estrus status ovary (22.6/63.8%) was also significantly higher rather than that in anestrus status ovary (8.2/51.6%). Nuclear development to MI of over 110 ${\mu}{\textrm}{m}$ in estrus ovary (24.3%) was significantly higher rather than those in under 110 ${\mu}{\textrm}{m}$ or over and under 110 ${\mu}{\textrm}{m}$ in anestrus (2.5, 6.8 and 0.0%), respectively (P ＜ 0.05). Nuclear development to AT and MII of over 110 ${\mu}{\textrm}{m}$ in estrus was more developed in other groups. Nuclear development to MI in TCM199 (21.8%) was significantly higher than in $\alpha$-MEM (10.0%). Altho $\mu\textrm{g}$h the development rate to AT was significantly different between TCM199 (7.3%) and $\alpha$-MEM (1.1%), but to MII was not different between TCM199 (0.9%) and $\alpha$-MEM (1.1%). The results indicated that over 110 ${\mu}{\textrm}{m}$ oocytes was could be recovery from estrus status ovary, bigger oocytes were more developed to MI, AT or MII in TCM199.