Epigenetic change in IGF2R is associated with fetal overgrowth after sheep embryo culture.

Manipulation or non-physiological embryo culture environments can lead to defective fetal programming in livestock. Our demonstration of reduced fetal methylation and expression of ovine IGF2R suggests pre-implantation embryo procedures may be vulnerable to epigenetic alterations in imprinted genes. This highlights the potential benefits of epigenetic diagnostic screening in developing embryo procedures.

Regulators of adipocyte precursor cells.

Lean and adipose tissue growth are two of the most important targets for manipulation in commercial livestock. Adipose tissue growth occurs by both hyperplasia and hypertrophy. The processes involved in adipocyte hypertrophy are relatively well understood but much less is known about adipocyte hyperplasia.

Decreased muscle cell proliferation in chicks with a deletion in the GH receptor gene.

The increase in muscle weight in neonatal animals is a consequence of increased protein accretion and DNA content. GH increases protein accretion but direct effects of GH on myogenic cell proliferation have not been demonstrated. Sex-linked dwarfism in the chick is caused by mutation or deletion in the GH receptor gene and has provided a useful model to study the physiological consequences of GH insensitivity.