The insulin-like growth factor 2 receptor gene ( ) encodes a transmembrane receptor that binds and regulates bioavailability of insulin-like growth factor 2, a potent growth promoting hormone. Mouse gene knockout experiments have demonstrated the essential role of in prenatal growth and development. The gene is subject to genomic imprinting and expressed from the maternal allele in mouse and bovine, but is not imprinted in human. Imprinted expression is regulated by expression of a partially overlapping, reciprocally imprinted noncoding antisense RNA, AIRN. We analyzed expression of and AIRN in brain, cotyledon, heart kidney, liver, lung and skeletal muscle of bovine Day153 fetuses with Bos taurus (Angus), Bos indicus (Brahman) and B. taurus × B. indicus reciprocal cross genetics (n = 74) by real time quantitative PCR to determine effects of fetal genetics and sex. Statistical analysis of qPCR data in general linear models (PASW Statistics 19) showed that AIRN expression in brain, and expression in cotyledon, was affected by fetal genetics (ANOVA, both P < 0.001). Expression of Angus (dam) fetuses compared with all 3 other groups of fetuses (t-tests P < 0.01). In addition, expression of in skeletal muscle was affected by an interaction between fetal sex and genetics (P < 0.05) where female fetuses with Brahman maternal genetics showed sigof expression for and AIRN which is controlled by the interplay between genetics, epigenetics and fetal sex.

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