Independent regulation of skeletal growth by Ihh and IGF signaling

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2006.06.042 Byline: Fanxin Long (a)(b)(c), Kyu-Sang Joeng (a)(c), Shouhong Xuan (d), Argiris Efstratiadis (d), Andrew P. McMahon (e) Keywords: Ihh; Smo; IGF; IGF1R; Growth; Skeleton; Mouse Abstract: The insulin-like growth factors (IGFs) play a major role in regulating the systemic growth of mammals. However, it is unclear to what extent their systemic and/or local functions act in concert with other local growth factors controlling the sizes of individual organs. We have specifically addressed whether growth control of the skeleton by IGFs interacts genetically with that by Indian hedgehog (Ihh), a locally produced growth signal for the endochondral skeleton. Here, we report that disruption of both IGF and Ihh signaling resulted in additive reduction in the size of the embryonic skeleton. Thus, IGF and Ihh signaling appear to control the growth of the skeleton in parallel pathways. Author Affiliation: (a) Department of Medicine, Washington University Medical School, St. Louis, MO 63110, USA (b) Department of Molecular Biology and Pharmacology, Washington University Medical School, St. Louis, MO 63110, USA (c) Division of Biology and Biomedical Sciences, Washington University Medical School, St. Louis, MO 63110, USA (d) Department of Genetics and Development, Columbia University, New York, NY 10032, USA (e) Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA Article History: Received 23 January 2006; Revised 20 June 2006; Accepted 26 June 2006