Expression and location of IGF binding proteins-2, -4, and -5 in developing fetal tissues

• Published in: Journal of animal science Vol. 77; no. 6; pp. 1431 - 1441
• Main Authors: Gerrard, D. E, Okamura, C. S, Grant, A. L
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01.06.1999; American Society of Animal Science; Oxford University Press
• Subjects: Animals; Biological and medical sciences; Blotting, Northern - veterinary; Embryology: invertebrates and vertebrates. Teratology; Embryos; Female; Fundamental and applied biological sciences. Psychology; Hogs; Humans; Immunohistochemistry; In Situ Hybridization - veterinary; Insulin-Like Growth Factor Binding Protein 2 - analysis; Insulin-Like Growth Factor Binding Protein 2 - biosynthesis; Insulin-Like Growth Factor Binding Protein 4 - analysis; Insulin-Like Growth Factor Binding Protein 4 - biosynthesis; Insulin-Like Growth Factor Binding Protein 5 - analysis; Insulin-Like Growth Factor Binding Protein 5 - biosynthesis; Muscles - embryology; Muscular system; Organogenesis. Fetal development; Organogenesis. Physiological fonctions; Pregnancy; Proteins; RNA Probes - metabolism; RNA, Complementary - metabolism; Swine - embryology; Tissues; Insulin like growth factor binding protein; Embryonic development; Vertebrata; Mammalia; Animal; Fetus; Artiodactyla; Gene expression; Localization; Striated muscle; Ungulata; Pig
• ISSN: 0021-8812; 1525-3163; 0021-8812
• DOI: 10.2527/1999.7761431x

Insulin-like growth factors are associated with myogenesis in vivo, and their actions are mediated by IGF binding proteins (IGFBP). Sites of IGFBP production and their location during early development are not clear. The objective of this research was to examine the developmental expression and location of IGFBP-2, -4, and -5 mRNA and peptides in developing porcine skeletal muscle and liver. Pregnant pigs were euthanatized at various times postconception (pc). Developmental expression of IGFBP was evaluated using total RNA extracted from skeletal muscle and liver of 30-, 44-, 59-, 68-, 75-, 89-, and 109-d pc fetuses and from adult and neonatal pigs. Localization of IGFBP-2, -4, and -5 mRNA and peptides was examined by in situ hybridization and immunocytochemistry of muscle samples from contralateral pelvic limbs of each pig. Overall muscle IGFBP gene expression decreased (P < .05) with increasing age. Moreover, expression of liver IGFBP-2 and -5, but not of IGFBP-4, was greater (P < .05) during prenatal than during postnatal periods. The majority of immunoreactive IGFBP was located in developing muscle cells, with little localized to connective tissue, except at later stages of development. These data show that IGFBP-2, -4, and -5 expression is time- and tissue-dependent in fetal liver and muscle.