Open AccessIGF-I is required for normal embryonic growth in mice.
Author(s) -
Lyn Powell-Braxton,
P G Hollingshead,
Corinna Warburton,
Mary Dowd,
Sharon Pitts-Meek,
Dyana K. Dalton,
Nancy A. Gillett,
Timothy A. Stewart
Publication year - 1993
Publication title -
genes and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.136
H-Index - 438
eISSN - 1549-5477
pISSN - 0890-9369
DOI - 10.1101/gad.7.12b.2609
Subject(s) - biology , embryonic stem cell , environmental ethics , microbiology and biotechnology , genetics , gene , philosophy
IGF-I is a pleiotropic hormone reported to affect linear growth, glucose metabolism, organ homeostasis, and the immune and neurologic systems. In contrast to IGF-II, IGF-I is expressed at low levels embryonically and has been thought to be more important for postnatal growth and development. To investigate the role of IGF-I in normal development we generated mice with an inactive IGF-I gene by homologous recombination in ES cells. Heterozygous mice are healthy and fertile, but they are 10-20% smaller than wild-type littermates and have lower than normal levels of IGF-I. The size reduction is attributable to a decrease in organs and muscle and bone mass. However, all tissues appear histologically normal. At birth homozygous mutant mice (IGF-I-/-) are < 60% body weight of wild type. Greater than 95% of IGF-I-/- pups die perinatally. Histopathology is characterized by underdevelopment of muscle tissue. Lungs of late embryonic and neonates also appeared less organized with ill-defined alveolae. IGF-I appears to be essential for correct embryonic development in mice.