30 GROWTH AND REPRODUCTIVE SUCCESS OF CLONED MALE CATS DERIVED FROM ADULT SOMATIC CELL NUCLEAR TRANSFER

Abstract

There have been very few published reports on the normal growth and fertility of cloned cats derived from adult somatic cell nuclear transfer (SCNT). Here, we report studies investigating the growth and fertility of cloned male cats produced by SCNT. This study was designed to investigate the reproductive success by natural breeding of cloned male cats with domestic female cats and to measure endocrine hormone profiles related to male reproduction such as testosterone, LH, and FSH. Clones A, B, and C produced 3, 2, and 4 kittens, respectively, after natural mating with 4 domestic female cats, and clone D produced 5 kittens, in spite of being further into puberty than the other cloned male cats. All of the females delivered at 64 to 66 days after natural mating. The results obtained are presented as the mean ± SEM. Sexual hormones were analyzed by ANOVA. All statistical analysis was conducted with SAS (SAS Institute Inc., Cary, NC, USA), and P < 0.05 was considered significant. Three of the 14 kittens expressed an odd eye color, which was produced from 1 clone A and 2 clone B cats. The eye color of other F1 kittens varied from brown to blue. Body weight at birth ranged from 72.9 to 134 g. Although clone D had a lower libido and entered puberty later than the other cloned males, it produced gonadal hormones within the average range. Four cloned male cats had normal fertility and were free from any reproductive problems. All of the cloned male cats were similar to two control and donor cats with respect to concentration of gonadal hormones. However, the concentration of testosterone in a castrated donor cat was significantly lower than that from clones A, B, C, D, and control cats (0.4 ± 0.1 vs. 5.99 ± 5.68; 3.46 ± 2.81; 6.41 ± 2.17; 3.75 ± 0.34; 4.0 ± 3.63 ng mL^-1; P < 0.05). The concentrations of LH and FSH were not significantly different among any of the cats. A total of 14 kittens, 7 male and 7 female, were produced by the natural breeding of cloned male cats with 4 domestic female cats. These results indicate that cloned male cats have normal reproductive success and lie within the normal range of gonadal hormone production. All of the F1 kittens were produced by natural breeding, delivery, demonstrated normal growth, and are still alive and healthy.

This work was supported by KOSEF (grant M10525010001-05N2501-00110).