Y. K. Jo

Species-specific challenges in dog cloning.

Somatic cell nuclear transfer (SCNT) is now an established procedure used in cloning of several species. SCNT in dogs involves multiple steps including the removal of the nuclear material, injection of a donor cell, fusion, activation of the reconstructed oocytes and finally transfer to a synchronized female recipient. There are therefore many factors that contribute to cloning efficiency. By performing a retrospective analysis of 2005-2012 published papers regarding dog cloning, we define the optimum procedure and summarize the specific feature for dog cloning.

Timing of fertile period for successful pregnancy in American Bully dogs

Determination of the timing of the estrus cycle is essential for fertile mating. There are physiological variations among breeds, between bitches, and between cycles of the same bitch. If serial monitoring and many tools are applied, the exact moment of ovulation could be pin-pointed. However, it leads to time and costly difficulties. Progesterone concentrations during estrus cycles follow a specific pattern, and it is largely used in timing of fertile period. Although it has similar pattern in general, it is likely that breed-specific differences exist. The aim of this study was to investigate the way of timing the fertile period for successful pregnancy in American Bully dogs based on vaginal cytology and progesterone assay with minimized cost. To identify the empirical relations among reproductive characteristics, we performed statistical analyses on data from proestrus-to-estrus 27 American Bully dogs referred for 7 months. We found the significant correlations between the cyclic changes of vaginal cytology and progesterone assay. The relationship of serum progesterone concentrations with the days from vaginal discharge onset was analyzed through linear regression assay. In conclusion, we addressed two standards in the timing of fertile period with a minimal number of progesterone assays in the breeding management of American Bully dogs.