How healthy are clones and their progeny: 5 years of field experience

Panarace, M.; Agüero, Jaume; Garrote, M. Rodriguez; Jaúregui, G.; Segovia, A.; Cané, L.; Gutiérrez, Jessica; Marfil, M.; Rigali, F.; Pugliese, M; Young, Stacy; Lagioia, J.; Garnil, C.; Pontes, J.E. Forte; Junio, J.C. Ereno; Mower, S.A.; Medina, María

doi:10.1016/j.theriogenology.2006.09.036

Cited by 133 publications

(114 citation statements)

References 30 publications

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“…In our conditions, the 3-year observation period did not reveal differences between a large number of clones and controls with regard to growth rate, food intake and clinical evaluation up to adulthood, confirming previous observations (Lanza et al, 2001;Heyman et al, 2004;Panarace et al, 2007). The data on lactation of clones are in agreement with previously published data on milk produced by a limited number of animals (Walsh et al, 2003;Tian et al, 2005).…”

Section: Discussionsupporting

confidence: 92%

Quality and safety of bovine clones and their products

Heyman

Chavatte‐Palmer

Fromentin³

et al. 2007

Animal

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A multidisciplinary research programme was developed to get a scientific expertise for the quality assessment of products obtained from cloned livestock. Thirty-seven bovine Holstein female clones of five different genotypes and their products were analysed in comparison with 38 control animals obtained by conventional artificial insemination and raised under the same conditions at the same experimental farm. Animal evaluation included over 150 criteria and more than 10 000 measurements to check the physiological status and health over a 3-year period. All the parameters studied were in the normal range for age and breed, but some significant differences were detected between clone and control groups in terms of delayed onset of puberty in clones, higher neutrophil counts in haematology or lower biochemical plasma concentrations of gamma glutamyl transferase. Milk and meat analyses were conformable to expected values. We, however, found some differences in fatty acid (FA) composition of milk and muscle suggesting a possible deviation in lipid metabolism as assessed by higher delta-9 desaturase activity indexes in both milk and muscles from clones compared with controls. Repeated muscle biopsies in the semitendinosus muscle of the same animals demonstrated a higher oxidative activity in muscle of young clones (8 months of age) compared with controls, suggesting a delayed muscle maturation in clones. Nutritional evaluation of milk and meat using the rat feeding trials did not show any difference between clone and control products for food intake, growth rate, body composition of the rats, nor for possible allergenicity. Possible reactivation of bovine endogenous retroviruses (BERVs) was analysed and compared between normal and cloned cattle. As expected, these BERV sequences are not transcribed and no RNA was detected in the blood of clones, donor animals or controls; therefore, it may be assumed that the sanitary risk associated with BERV sequences is not higher in cattle derived from somatic nuclear transfer than in cattle born from conventional reproduction. Our results confirm that the quality and safety of products (milk and meat) from adult and clinically healthy cloned cattle is globally similar to normal animals. However, from a strictly biological point of view, the slightly delayed maturation we observed in the muscle of clones together with some marginal differences identified in FA composition of both muscle and milk, point to the need for more refined analysis to totally exclude any risks from the consumption of those products.

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Section: Discussionsupporting

confidence: 92%

Quality and safety of bovine clones and their products

Heyman

Chavatte‐Palmer

Fromentin³

et al. 2007

Animal

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“…Although SCNT is more efficient in cattle than in any other species tested so far, a recent survey covering the results of bovine cloning in Brazil, Argentina, and the United States over a 5-year period revealed that only 9% of the SCNT embryos transferred to recipients resulted in the birth of a live calf (317 calves from 3374 embryos transferred to 293 surrogate dams). The proportion of live calves per transferred embryos is only 8% and 7% at 1 and 150 days after birth, respectively (4). In general, the failures of cloning are attributed to problems with the reprogramming of a nucleus derived from a differentiated cell.…”

mentioning

confidence: 99%

The endometrium responds differently to cloned versus fertilized embryos

Bauersachs

Ulbrich

Zakhartchenko³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

187

144

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Although somatic cell nuclear transfer (SCNT) cloning is more efficient in cattle than in any other species tested so far, there is a high rate of pregnancy failure that has been linked to structural and functional abnormalities of the placenta. We tested the hypothesis that these changes may originate from disturbed embryo-maternal interactions in the peri-implantation period. Therefore, we evaluated the response of the endometrium to SCNT embryos (produced from 7 different fetal fibroblast cell lines) as compared with embryos derived from in vitro fertilization (IVF). SCNT embryos and IVF embryos were cultured under identical conditions to the blastocyst stage (day 7) and were transferred to corresponding recipients, which were slaughtered at day 18 of pregnancy. The mRNA profiles of endometrium samples were obtained using a custom cDNA microarray enriched for transcripts differentially expressed in the endometrium and/or oviduct epithelium during the estrous cycle and/or early pregnancy. Overall, the variation in mRNA profiles was greater in the SCNT group than in the IVF group. Furthermore, 58 transcripts were differentially abundant in endometria from SCNT and IVF pregnancies. Prominent examples are orphan nuclear receptor COUP-TFII and connexin 43, both known to play important roles in uterine receptivity and conceptus placentation. These findings suggest that placental failure in bovine clone pregnancies may originate from abnormal embryomaternal communication that develops during the peri-implantation period. Endometrium transcriptome profiles may serve as a tool to evaluate SCNT embryos for their ability to establish pregnancy and develop a functional placenta.Bos taurus ͉ cloning ͉ early pregnancy ͉ gene expression ͉ microarray C loning by somatic cell nuclear transfer (SCNT) (1) is an important strategic tool for animal breeding and biotechnology. For example, animals carrying rare desired alleles can be multiplied to introduce the desired allele into the breeding population. The life span and capacity of valuable breeding animals and the physiologically limited number of offspring of female animals can be increased, thus enhancing selection intensity. Moreover, cloning allows the propagation of desired genotypes without the risk of genetic recombination that is inherent to sexual reproduction. In animal biotechnology, SCNT using genetically modified donor cells is a powerful approach for the generation of transgenic animals (2) and so far is the only technique facilitating targeted mutagenesis in livestock species (3). Moreover, cloning can be used to multiply transgenic animals and to propagate multitransgenic individuals without segregation of the individual transgenes.Despite the plethora of important applications of cloning, the efficiency of this technology still is very low. Although SCNT is more efficient in cattle than in any other species tested so far, a recent survey covering the results of bovine cloning in Brazil, Argentina, and the United States over a 5-year period revealed that only 9...

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“…The success rates in terms of live offspring per transferred NT-embryo range from 10% to 25% for cattle, from 3% to 8% for goat and sheep and from 1% to 5% for pig cloning. It has been observed that certain cell cultures repetitively did not allow the generation of live offspring (Panarace et al, 2006). The reasons for this are unclear.…”

Section: Discussionmentioning

confidence: 99%

A protocol for the cryoconservation of breeds by low-cost emergency cell banks – a pilot study

Groeneveld¹,

Tinh

Kues³

et al. 2008

Animal

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A protocol was developed for collection and storage of somatic cell samples under adverse conditions with little infrastructure, for somatic-cell banks as a backup for endangered livestock breeds. The procedure, which is uniform across species, includes sample collection with ear taggers with an integrated tag/vial system, and recording of global positioning system (GPS) coordinates, digital images and breed information. In a pilot study, the procedures were tested on six local Vietnamese populations of pigs, sheep and goats. Initial investment was around h3000, while the total variable cost for sampling one breed with 25 females and 25 males was less than h1000. With support from local organisations, the sampling of six breeds with 300 animals was carried out in 2 months. The protocol and the complete workflow for setting up a somatic-cell bank, together with data collection, are described. The procedure has proved practicable and exceedingly cheap relative to the cryopreservation of semen or embryos.

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How healthy are clones and their progeny: 5 years of field experience

Cited by 133 publications

References 30 publications

Quality and safety of bovine clones and their products

Quality and safety of bovine clones and their products

The endometrium responds differently to cloned versus fertilized embryos

A protocol for the cryoconservation of breeds by low-cost emergency cell banks – a pilot study

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