Regulation of skeletal muscle growth and gene expression by insulin-like growth factors and myostatin
type: CreativeWork
description: Insulin-like growth factor 2 (IGF2) is a maternally imprinted growth factor that is thought to primarily promote prenatal skeletal muscle growth. A SNP within intron 3 of IGF2 identified as IGF2-intron3-G3072A has a considerable impact on lean yield as a result of increased postnatal IGF2 expression. Our first objective was to characterize carcass cutting yields of pigs with paternal A alleles (APat) and paternal G alleles (GPat) and determine how the mutation affects fresh meat quality and bacon processing. A single heterozygote (AG) boar was bred to homozygous (AA) commercial Yorkshire-cross sows producing F1 barrows and gilts with either GPat or APat alleles. Loin eye area was 10% greater (P = 0.01) and back fat was reduced (P = 0.01) 15% in APat pigs compared with GPat pigs. Consequently, boneless carcass cutting yield was increased (P < 0.01) 2.34 percentage units in APat pigs compared with GPat pigs. Mutations that improve carcass lean yield are often associated with reduced meat quality; however, fresh LM quality was minimally affected by the genotype, as 24-hour pH, drip loss and shear force was not different (P ≥ 0.27) between APat pigs and GPat pigs. Despite the reduced subcutaneous fat accumulation, LM intramuscular extractable lipid was 0.64 percentage units greater (P = 0.02) in APat pigs compared with GPat pigs. While not statistically different (P = 0.30), the magnitude of difference in slicing yield as a percentage of green weight was 1.57 percentage units between bellies from APat pigs (85.83%) and bellies from GPat pigs (87.40%). Therefore, while APat pigs yielded a greater amount of lean product, this may have been at the expense of reduced bacon slicing yields. Our next objectives were to determine the contributions of hyperplasia and hypertrophy to increased muscle mass and delineate the effect of the IGF2 mutation on the expression of myogenic genes during prenatal and postnatal growth. While postnatal IGF2 expression is known to be greater in …
abstract: Insulin-like growth factor 2 (IGF2) is a maternally imprinted growth factor that is thought to primarily promote prenatal skeletal muscle growth. A SNP within intron 3 of IGF2 identified as IGF2-intron3-G3072A has a considerable impact on lean yield as a result of increased postnatal IGF2 expression. Our first objective was to characterize carcass cutting yields of pigs with paternal A alleles (APat) and paternal G alleles (GPat) and determine how the mutation affects fresh meat quality and bacon processing. A single heterozygote (AG) boar was bred to homozygous (AA) commercial Yorkshire-cross sows producing F1 barrows and gilts with either GPat or APat alleles. Loin eye area was 10% greater (P = 0.01) and back fat was reduced (P = 0.01) 15% in APat pigs compared with GPat pigs. Consequently, boneless carcass cutting yield was increased (P < 0.01) 2.34 percentage units in APat pigs compared with GPat pigs. Mutations that improve carcass lean yield are often associated with reduced meat quality; however, fresh LM quality was minimally affected by the genotype, as 24-hour pH, drip loss and shear force was not different (P ≥ 0.27) between APat pigs and GPat pigs. Despite the reduced subcutaneous fat accumulation, LM intramuscular extractable lipid was 0.64 percentage units greater (P = 0.02) in APat pigs compared with GPat pigs. While not statistically different (P = 0.30), the magnitude of difference in slicing yield as a percentage of green weight was 1.57 percentage units between bellies from APat pigs (85.83%) and bellies from GPat pigs (87.40%). Therefore, while APat pigs yielded a greater amount of lean product, this may have been at the expense of reduced bacon slicing yields. Our next objectives were to determine the contributions of hyperplasia and hypertrophy to increased muscle mass and delineate the effect of the IGF2 mutation on the expression of myogenic genes during prenatal and postnatal growth. While postnatal IGF2 expression is known to be greater in …
author: Clark, Daniel
language: eng
keywords: Porcine, Insulin-like growth factor, Mice, Myostatin, Quantitative trait loci, Single nucleotide polymorphism
date published: 2015-01-21T19:47:51Z
date modified: 2026-07-22T22:26:07Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/72764