39 FACTORS AFFECTING PREGNANCY RATE FOLLOWING TRANSFER OF SOMATIC CELL NUCLEAR TRANSFER EMBRYOS IN DOGS
M. J. Kim A , H. J. Oh A , J. E. Park A , J. T. Kang A , S. G. Hong A , O. J. Goo A , D. Y. Kim A and B. C. Lee ASeoul National University, Seoul, South Korea
Reproduction, Fertility and Development 21(1) 119-119 https://doi.org/10.1071/RDv21n1Ab39
Published: 9 December 2008
Abstract
There have been attempts to find out factors influencing pregnancy rate after transfer of somatic cell nuclear transferred (SCNT) couplets in several species. The purpose of this study was to investigate the effects of parity, surgical history, and synchronization state between oocytes donor and recipient on the pregnancy rate following transfer of SCNT embryos in dogs. A total of 25 mixed-breed female dogs, aged 1 to 5 years old, weighing 20 to 35 kg were used in this study. In vivo-matured oocytes, obtained by flushing uterine tubes of donor dogs approximately 72 h after ovulation, were used for SCNT. Ovulation was determined by daily serum progesterone concentration. Reconstructed embryos (range = 7–36, average = 18.0 embryos) with normal morphology were surgically transferred into the ampullary portion of the uterine tube of recipient dogs. Pregnancy was determined at least 26 days after transfer by untrasonography. In experiment 1, recipient females were divided into 2 groups: nulliparous (7 bitches) and multiparous (17 bitches) groups. In experiment 2, recipient females were divided into 2 groups by surgical history: operated (10 bitches) and non-operated (14 bitches) groups. Operated group included those with a history of 1 laparotomy, either flushing of uterine tubes or SCNT embryo transfer. Non-operated group included those without history of any surgery. In experiment 3, recipient females were divided into 2 groups: synchronous (13 bitches) and asynchronous (7 bitches) groups. Synchronous was defined that the oocyte donor dog and the recipient dog ovulate at the same day. Asynchronous was defined that the oocyte donor dog ovulates 1 day earlier than the recipient. Data were analyzed using the Statistical Analysis System program (SAS Institute, version 9.1, Cary, NC, USA). In experiment 1, pregnancy rate was significantly higher in the multiparous group than the nulliparous group (23.5 v. 14.2%, P < 0.05). In experiment 2, surgical history did not influence the pregnancy rate between operated and non-operated groups (20.0 and 21.4%, respectively). In experiment 3, pregnancy rate was significantly higher in the asynchronous group than the synchronous group (42.9 v. 15.4%, P < 0.05). In conclusion, multiparous bitches improved the efficiency of SCNT embryo transfer. A higher pregnancy rate resulted when the oocyte donor dog’s ovulation time was 1 day earlier than that of the recipient dog. Other factors should be investigated for further improvement of the SCNT embryo transfer efficiency.
This study was financially supported by the Korean MEST, through KOSEF (grant # M10625030005-08N250300510) and the BK21 program for Veterinary Science, and SNU foundation (Benefactor; RNL BIO).
