Abstract:The purpose of this study was to develop a strain of canine X-linked muscular dystrophy (CXMD), a model of Duchenne muscular dystrophy, in Japan. A female beagle was artificially inseminated with frozen-thawed spermatozoa derived from an affected golden retriever. Subsequently, two carrier female dogs (G1 carriers) and four normal male littermates were produced. Thereafter, the two G1 carriers were mated with beagle sires. As a result, each bitch whelped three times, and out of 54 pups, 17 affected male descendants, and 11 carrier female descendants (G2 carriers) were detected. One G2 carrier was then mated with a beagle sire and 15 pups in two whelpings were produced, including five affected males and four carrier females (G3 carriers). A total of 10 female beagles were artificially inseminated to evaluate the fertility of the frozen-thawed spermatozoa from the two affected dogs. The whelping rates of the two affected dogs were 4/5 and the litter sizes were 5.0 ± 1.41 and 6.0 ± 0.82, respectively. These results indicate that a canine X-linked muscular dystrophy colony has been established in Japan. We called them CXMD J .

Abstract. The purpose of this study was to examine fertilities from mating and artificial insemination (AI) with frozen-thawed spermatozoa by indexing the luteinizing hormone (LH) surge with the Canine Ovulation Timing Test (ICG Status-LH TM ) in beagle bitches. Eleven 2-8-year-old multiparous dogs were used for this experiment and blood was collected daily at 6-15 days after the onset of proestrus. Each serum sample was then used for detection of the LH surge. Five dogs were mated at 5 days after the LH surge. Whelping was successful in all dogs and litter size was 5.8 ± 1.9 (Mean ± SD). The remaining 6 dogs were artificially inseminated with frozen-thawed spermatozoa at 4, 5 and 6 days after the LH surge. Sperm motility after thawing was 49.6 ± 3.6%. All dogs whelped and litter size was 4.0 ± 3.0. These results suggest that fertilities from mating and AI with frozen-thawed spermatozoa are satisfactory by indexing the LH surge with the Canine Ovulation Timing Test in dogs and further demonstrate that the optimal period for insemination is around 5 days after the LH surge.