US Food and Drug Agency

“ From a breeder’s perspective, phenotypes resulting from sexual reproduction cannot be predicted—that is, the characteristics of the offspring from a mating may be estimated, but not predicted with certainty. Nuclear transfer, the most advanced of these technologies, does not require fertilization and allows for the propagation of known genotypes and phenotypes without the risk of genetic reshuffling. ”

“ Following an overview of the available data on animal clones, the report indicated that the most likely mechanism for generating hazards to clones would stem from reprogramming of the donor cell genome, and that any harms that might result from that reprogramming would be observed early in a clone’s development. ”

“ Assessing the safety of food products from animal clones and their progeny6 is best accomplished by using both approaches: prospectively drawing on our knowledge of biological systems in development and maturation, and in retrograde, from an analysis of food products. Subtle hazards and potential risks that may be posed by animal clones must, however, be considered in the context of other mutations and epigenetic changes that occur in all food animal populations. ”

“ Unpublished data were provided to us in raw, unanalyzed form, which we subsequently analyzed. CVM determined whether a particular publication or dataset was relevant to the analysis. These judgments were framed by the two overarching objectives of the Risk Assessment: determining whether cloning poses any health risks to the animals involved in the cloning process, and whether any hazards arise during the development of clones or their progeny that may pose food consumption risks. ”

“ Sexually derived progeny of animal clones appear to be normal and healthy. As described in Chapter IV, any residual epigenetic reprogramming errors in clones are expected to be reset during gametogenesis, resulting in production of normal offspring by sexual reproduction. Consistent with these predictions, the data on the health status of clone progeny indicate that there is no increased risk of health problems in these animals compared with conventional animals. ”

“ Sheep Clones Except by relying on underlying biological assumptions, and by inference from other species, there is insufficient information on the health status of sheep clones to draw conclusions with respect to potential risks that could be posed from the consumption of food products. ”

“ Data on reproductive function in cows or bulls of this age cohort indicates that healthy bovine clones surviving to reproductive maturity function normally and produce healthy offspring. These observations are consistent across studies. Given that reproduction is the most difficult "biological hurdle" placed on an organism, the observation of normal reproductive function provides an additional degree of confidence in the conclusion regarding the appropriate development of these animals. ”

“ D. The Implications of Epigenetic Reprogramming for Clones and their Progeny (Chapter IV) Epigenetics has been defined as the study of stable alterations in gene expression potentials that arise during development and cell proliferation. In sexual reproduction, a new diploid genome is created by the fusion of two haploid genomes. The subsequent expression of that genome into a functional organism is governed by a "program." There are several examples of epigenetic control of gene expression, of which DNA methylation is likely the best characterized. ”

“ These comparisons formed the basis of our determination of whether meat or milk from clones differs materially from meat or milk from conventional animals, and thus contributed to the overall conclusions regarding food consumption risks.
Weight of evidence: Weight of evidence evaluations do not rely on a single study or even a subset of studies. Instead, they are based on expert judgments on all of the information gathered in the course of a risk assessment. ”

“ It is important to note that this Risk Assessment is a scientific document that provides a framework by which science-based questions regarding animal health and food consumption risks are evaluated. CVM recognizes that cloning raises many ethical and economic concerns. ”

“ Goat Clones Edible products from goat clones pose no additional food consumption risk (s) relative to corresponding products from contemporary conventional comparators.
This conclusion is based on the same underlying biological assumption cited for the other livestock species, and a relatively small but compelling dataset. Once clone embryos are transferred to surrogate dams and pregnancies are confirmed, the "success rate" for live births is quite high. ”

“ Relative to clones, it is more likely the progeny of clones will be used to produce meat and milk for human consumption. 7 Empirical refers to that which can be seen or observed alone, often without reliance on theory. In the context of this risk assessment, conclusions drawn on empirical evidence are those that are drawn strictly based on the data. ”

“ Swine and goat clones, as well as clone calves that are not adversely affected by congenital abnormalities, appear healthy throughout the juvenile period and exhibit normal patterns of growth and development. ”

“ Many of these are lethal, as demonstrated by the low success rate of IVF and the even lower success rate of SCNT. In the small number of successful cases that ultimately result in clones that appear normal and healthy, reprogramming in SCNT-derived embryos appears to be as successful as reprogramming in fertilization-derived embryos. Live and apparently healthy clones may exhibit some level of epigenetic differences relative to fertilization-derived animals, but these differences do not appear to have adverse effects on their well-being or ability to grow and develop normally. ”

“ E. Risks to Animals Involved in Cloning (Chapter V) To identify the potential hazards and assess any resulting risks to animals associated with cloning, Chapter V focuses on the health of clones at all five developmental nodes (pregnancy and parturition, perinatal, juvenile, reproductive, post-pubertal) . Health risks to surrogate dams carrying clone fetuses are also considered, and the health outcomes of SCNT are compared with the outcomes of other ARTs. ”

“ These technologies form a continuum that ranges from the fairly minimal assistance provided to animals engaged in natural service through the more recent development of SCNT. ARTs have aided in the genetic improvement of domestic livestock species by the selection and propagation of desirable phenotypes, and accelerating the rate at which those characteristics have been incorporated into national herds. ”

“ Most commonly used ARTs rely on fertilization as a first step. This joining of egg and sperm is accompanied by the recombination of the genetic material from the sire and dam, and is often referred to as "shuffling the genetic deck." ”

“ Artificial insemination, for example, permitted the propagation of valuable genomes without the sire being physically present, thereby allowing superior genetics to be spread beyond relatively small geographical areas. ”

“ Currently, it is not possible to draw any conclusions regarding the longevity of livestock clones or possible long-term health consequences associated with cloning due to the relatively short time that the technology has existed. ”