Progeny of somatic cell nuclear transfer (SCNT) pig clones are phenotypically similar to non-cloned pigs

Abstract

Systematic studies of cloned animals generated from adult somatic cell nuclei are critical in assessing the utility of somatic cell cloning in various applications, including the safety of food products from cloned animals and their offspring. Previously, we compared somatic cell derived cloned pigs with naturally bred control pigs on a series of physiological and genetic parameters. We have extended our studies to the F1 progeny of these clones to see whether these phenotypic differences are transmitted to the next generation. There were no differences in the average litter size between litters from cloned gilts and naturally bred controls (7.78 +/- 2.6 and 7.40 +/- 3.0, respectively; mean +/- SD) or in the degree of litter size variation (coefficients of variation of 33.4% and 40.5% for litters of clones and controls, respectively). Similarly there were no statistical differences between sex ratios of cloned litters (51-49%, M:F) and control litters (59-41%, M:F). Blood profiles between cloned pigs, control pigs, and their progeny were compared at two time points (i.e., 15 and 27 weeks) to quantify the effect of cloning on various blood parameters and their transmission to the next generation. Although the range of values for all traits overlapped between different classes, the variability between all the traits in F1 progeny of clones and the control pigs was similar at 15 and 27 weeks, with one exception. Combined, our data and previous results in mice strongly support the hypothesis that offspring of clones are similar to offspring of naturally bred animals, and as such there should not be any increased risks associated with consumption of products from these animals.