Tissue-specific and minor inter-individual variation in imprinting of IGF2R is a common feature of Bos taurus Concepti and not correlated with fetal weight

• Published in: PloS one 2013-04, Vol.8 (4), p.e59564-e59564
• Main Authors: Bebbere, Daniela, Bauersachs, Stefan, Fürst, Rainer W, Reichenbach, Horst-Dieter, Reichenbach, Myriam, Medugorac, Ivica, Ulbrich, Susanne E, Wolf, Eckhard, Ledda, Sergio, Hiendleder, Stefan
• Format: Article
• Language: English
• Subjects: Abnormalities; Alleles; Animals; Base Sequence; Bias; Biological evolution; Biology; Biotechnology; Bos taurus; Brain; Brain research; Breeding of animals; Cattle; Cattle - embryology; Cattle - genetics; Correlation; Deoxyribonucleic acid; DNA; DNA methylation; Female; Fertilization in Vitro; Fetal Weight - genetics; Fetus - metabolism; Fetuses; Gene dosage; Gene expression; Gene Expression Regulation, Developmental; Genes; Genomes; Genomic Imprinting; Genomics; Gestation; Humans; Imprinting; In vitro fertilization; Insulin; Insulin-like growth factor II receptors; Insulin-like growth factors; Kidneys; Laboratories; Liver; Lungs; Methylation; Mice; Molecular Sequence Data; Muscles; Organ Specificity; Physiology; Placenta; Placenta - metabolism; Pregnancy; Pregnant women; Receptor, IGF Type 2 - genetics; Reproductive strategy; Skeletal muscle; Species Specificity; Tissues; Variation; Veterinary medicine; Veterinary Science
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0059564

The insulin-like growth factor 2 receptor (IGF2R) is essential for prenatal growth regulation and shows gene dosage effects on fetal weight that can be affected by in-vitro embryo culture. Imprinted maternal expression of murine Igf2r is well documented for all fetal tissues excluding brain, but polymorphic imprinting and biallelic expression were reported for IGF2R in human. These differences have been attributed to evolutionary changes correlated with specific reproductive strategies. However, data from species suitable for testing this hypothesis are lacking. The domestic cow (Bos taurus) carries a single conceptus with a similar gestation length as human. We identified 12 heterozygous concepti informative for imprinting studies among 68 Bos taurus fetuses at Day 80 of gestation (28% term) and found predominantly maternal IGF2R expression in all fetal tissues but brain, which escapes imprinting. Inter-individual variation in allelic expression bias, i.e. expression of the repressed paternal allele relative to the maternal allele, ranged from 4.6-8.9% in heart, 4.3-10.2% in kidney, 6.1-11.2% in liver, 4.6-15.8% in lung and 3.2-12.2% in skeletal muscle. Allelic bias for mesodermal tissues (heart, skeletal muscle) differed significantly (P