Conservation of IGF2-H19 and IGF2R imprinting in sheep: effects of somatic cell nuclear transfer

Young, Lorraine; Schnieke, Angelika; McCreath, Kenneth J.; Wieckowski, Sébastien; Konfortova, Galia; Fernandes, Kenneth; Ptak, Grazyna; Kind, Alex J.; Wilmut, Ian; Loi, Pasqualino; Feil, Robert

doi:10.1016/j.mod.2003.09.006

Cited by 112 publications

(78 citation statements)

References 61 publications

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“…This loss of imprinting arose as a consequence of loss of DNA methylation in the second intron differentially methylated region (DMR) of that gene. Loss of methylation at this DMR, and a conserved DMR located upstream of the ovine H19 gene (H19, imprinted maternally expressed transcript (non-protein coding)), was prevalent among SCNT cloned lambs (Young et al 2003) and SCNT cloned calves , leading to biallelic expression of these imprinted genes.…”

Section: Epigenetic Programming Of Long-term Developmentmentioning

confidence: 99%

Epigenetics and developmental programming of welfare and production traits in farm animals

Sinclair

Rutherford

Wallace

et al. 2016

Reprod. Fertil. Dev.

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Abstract. The concept that postnatal health and development can be influenced by events that occur in utero originated from epidemiological studies in humans supported by numerous mechanistic (including epigenetic) studies in a variety of model species. Referred to as the 'developmental origins of health and disease' or 'DOHaD' hypothesis, the primary focus of large-animal studies until quite recently had been biomedical. Attention has since turned towards traits of commercial importance in farm animals. Herein we review the evidence that prenatal risk factors, including suboptimal parental nutrition, gestational stress, exposure to environmental chemicals and advanced breeding technologies, can determine traits such as postnatal growth, feed efficiency, milk yield, carcass composition, animal welfare and reproductive potential. We consider the role of epigenetic and cytoplasmic mechanisms of inheritance, and discuss implications for livestock production and future research endeavours. We conclude that although the concept is proven for several traits, issues relating to effect size, and hence commercial importance, remain. Studies have also invariably been conducted under controlled experimental conditions, frequently assessing single risk factors, thereby limiting their translational value for livestock production. We propose concerted international research efforts that consider multiple, concurrent stressors to better represent effects of contemporary animal production systems.

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Section: Epigenetic Programming Of Long-term Developmentmentioning

confidence: 99%

Epigenetics and developmental programming of welfare and production traits in farm animals

Sinclair

Rutherford

Wallace

et al. 2016

Reprod. Fertil. Dev.

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“…However, the existence of several growth-regulating imprinted genes in the fetal sheep and cow (36)(37)(38)(39)(40), asymmetric pronuclear demethylation in the monotocous human, and lack of demethylation in the polytocous rabbit zygote (12) provide no substantiation for an imprintmodifying role of paternal pronuclear demethylation. Another suggested function for paternal demethylation is to allow more rapid remodeling͞activation of the paternal genome in species where zygotic genome activation occurs relatively early (41).…”

Section: Function Of Pronuclear Demethylation?mentioning

confidence: 99%

The effect of interspecific oocytes on demethylation of sperm DNA

Beaujean

Taylor

McGarry

et al. 2004

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

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114

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In contrast to mice, in sheep no genome-wide demethylation of the paternal genome occurs within the first postfertilization cell cycle. This difference could be due either to an absence of a sheep demethylase activity that is present in mouse ooplasm or to an increased protection of methylated cytosine residues in sheep sperm. Here, we use interspecies intracytoplasmic sperm injection to demonstrate that sheep sperm DNA can be demethylated in mouse oocytes. Surprisingly, mouse sperm can also be demethylated to a limited extent in sheep oocytes. Our results suggest that the murine demethylation process is facilitated either by a spermderived factor or by male pronuclear chromatin composition.M ethylation of the DNA cytosine residues in CpG dinucleotides is part of the complex epigenetic mechanism that has evolved to silence genomic sequences where their transcription either is not required for development or may be detrimental to genomic stability (reviewed in refs. 1-3). DNA methylation also plays an important role in allele-specific repression at imprinted gene loci, regulating such processes as fetal growth and development as well as X inactivation (reviewed in refs. 4-6). Whereas the genome-wide methylation patterns and levels of differentiated somatic lineages remain largely constant, very dynamic changes have been reported to occur in the preimplantation embryo in association with the formation of pluripotent embryonic nuclei.After fertilization, the sperm and egg genomes are remodeled into pronuclei, which appose within the oocyte cytoplasm before the first embryonic mitosis. However, the highly condensed sperm chromatin requires extensive nuclear remodeling and protamine-histone exchange, unlike nucleosomal maternal chromatin. By using an antibody against 5-methylcytosine (5mC), the presumptive male pronucleus of mouse, rat, pig, human, and, to a lesser extent, cow embryos have been shown to actively demethylate before syngamy, whereas the female pronucleus retains genome-wide methylation (7-12). In contrast, active demethylation of the paternal genome is not observed in early sheep or rabbit embryos (with an intermediate state in the cow) (12), which suggests that it is not an obligate requirement for mammalian development. The discovery that the dramatic changes in DNA methylation associated with early formative events in the mouse embryo are not conserved in the sheep allows a unique opportunity to investigate the regulatory mechanisms involved. Mouse ooplasm can fully demethylate multiple male pronuclei in polyspermic embryos, which raises the question of whether the demethylating activity resides in the fertilized oocyte or is intimately associated with the sperm (10). We have now used interspecies intracytoplasmic sperm injection (ICSI) to mimic the events of normal fertilization and investigate whether species differences in the oocyte environment or sperm composition determines the extent of male pronuclear demethylation. Materials and MethodsAll animal procedures were under strict accordance with...

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“…About 112 genes or non-coding RNAs are known to be imprinted in humans and mice, and some of these are conserved in ruminants (Reik and Walter, 2001;Young et al, 2003;Morison et al, 2005). Dozens of them are involved in fetal growth and development, and are particularly important to normal placenta development and nutrient transport from placenta to fetus, especially amino acids and glucose (Tilghman, 1999;Constância et al, 2002).…”

Section: Discussionmentioning

confidence: 99%

Imprinted gene expression in in vivo- and in vitro-produced bovine embryos and chorio-allantoic membranes

Perecin

Méo²,

Yamazaki³

et al. 2009

Genet. Mol. Res.

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AbStRACt. Cloning by nuclear transfer is often associated with poor results due to abnormal nuclear reprogramming of somatic donor cells and altered gene expression patterns. We investigated the expression patterns of imprinted genes IGF2 and IGF2R in 33-to 36-day bovine embryos and chorio-allantoic membranes derived from in vivo-and in vitro-produced embryos by somatic cell nuclear transfer (SCNT), parthenogenetic activation, and in vitro fertilization (IVF). There was a lower IGF2 expression rate in the SCNT (0.19) and parthenogenetic (0.02) groups when compared to in vivo and IVF embryos (2.01; P < 0.05). In the chorio-allantoic membranes, IGF2 showed a baseline expression pattern (P < 0.05) in parthenotes (0.001) when compared to in vivo, IVF (3.13), and SCNT (0.98) groups. IGF2R was less expressed (P < 0.05) in SCNT chorio-allantoic membranes (0.25) when compared to the in vivo group. The low expression of IGF2 in parthenogenetic embryos and Alterations in the relative frequency of IGF2 and IGF2R transcripts were observed in SCNT-derived bovine embryos and chorioallantoic membranes, respectively, supporting the hypothesis that abnormalities in the expression of imprinted genes are causes of the low efficiency of SCNT procedures in this species.

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Conservation of IGF2-H19 and IGF2R imprinting in sheep: effects of somatic cell nuclear transfer

Cited by 112 publications

References 61 publications

Epigenetics and developmental programming of welfare and production traits in farm animals

Epigenetics and developmental programming of welfare and production traits in farm animals

The effect of interspecific oocytes on demethylation of sperm DNA

Imprinted gene expression in in vivo- and in vitro-produced bovine embryos and chorio-allantoic membranes

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