Tags

Type your tag names separated by a space and hit enter

IGF-I and insulin in the acquisition of limb-forming ability by the embryonic lateral plate.
Dev Biol. 1996 Jul 10; 177(1):291-9.DB

Abstract

Acquisition of limb-forming ability by discrete regions of the lateral plate of the chick embryo is dependent on a medial-lateral inductive signaling cascade moving sequentially from the area of Hensen's node to the somitic mesoderm, the intermediate mesoderm, and then to the prospective limb-forming regions of the lateral plate. IGF-I and insulin are expressed by medial tissues as they are influencing the prospective limb-forming regions of the lateral plate. Here we report that IGF-I and insulin, but not FGF-2 or FGF-4, induce the formation of limb bud-like structures in vitro from prospective limb regions before they have acquired the ability to form limbs independent of medial tissues, and also induce the formation of limb bud-like structures from the prospective flank. The limb bud-like structures induced by IGF-I and insulin possess a thickened cap of ectoderm along their distal tips that resembles the apical ectodermal ridge (AER) and this thickened distal apical ectoderm expresses the AER-characteristic homeobox-containing gene Msx-2. Like in normal limb buds, a population of highly proliferating cells which express the homeobox-containing gene Msx-1 are localized in the mesoderm directly subjacent to the thickened AER-like structures induced by IGF-I and insulin. However, the limb bud-like structures induced by IGF-I and insulin do not express sonic hedgehog, which encodes a secreted signaling molecule that has been implicated in regulating the anteroposterior patterning of the developing limb bud. IGF-I- and insulin-treated prospective limb explants give rise to rudimentary limbs containing identifiable skeletal elements when grafted into the coelom or to somites of host embryos. Overall, these results suggest that IGF-I and insulin may be endogenous signals produced by medial tissues that are involved in conferring limb-forming ability to the lateral plate and may promote the initial outgrowth of limb buds and possibly induce the AER. However, other signals are necessary to promote the expression of genes such as sonic hedgehog that regulate the patterning of the developing limb.

Authors+Show Affiliations

Department of Anatomy, University of Connecticut Health Center, Farmington, Connecticut, 06030, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8660895

Citation

Dealy, C N., and R A. Kosher. "IGF-I and Insulin in the Acquisition of Limb-forming Ability By the Embryonic Lateral Plate." Developmental Biology, vol. 177, no. 1, 1996, pp. 291-9.
Dealy CN, Kosher RA. IGF-I and insulin in the acquisition of limb-forming ability by the embryonic lateral plate. Dev Biol. 1996;177(1):291-9.
Dealy, C. N., & Kosher, R. A. (1996). IGF-I and insulin in the acquisition of limb-forming ability by the embryonic lateral plate. Developmental Biology, 177(1), 291-9.
Dealy CN, Kosher RA. IGF-I and Insulin in the Acquisition of Limb-forming Ability By the Embryonic Lateral Plate. Dev Biol. 1996 Jul 10;177(1):291-9. PubMed PMID: 8660895.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - IGF-I and insulin in the acquisition of limb-forming ability by the embryonic lateral plate. AU - Dealy,C N, AU - Kosher,R A, PY - 1996/7/10/pubmed PY - 1996/7/10/medline PY - 1996/7/10/entrez SP - 291 EP - 9 JF - Developmental biology JO - Dev Biol VL - 177 IS - 1 N2 - Acquisition of limb-forming ability by discrete regions of the lateral plate of the chick embryo is dependent on a medial-lateral inductive signaling cascade moving sequentially from the area of Hensen's node to the somitic mesoderm, the intermediate mesoderm, and then to the prospective limb-forming regions of the lateral plate. IGF-I and insulin are expressed by medial tissues as they are influencing the prospective limb-forming regions of the lateral plate. Here we report that IGF-I and insulin, but not FGF-2 or FGF-4, induce the formation of limb bud-like structures in vitro from prospective limb regions before they have acquired the ability to form limbs independent of medial tissues, and also induce the formation of limb bud-like structures from the prospective flank. The limb bud-like structures induced by IGF-I and insulin possess a thickened cap of ectoderm along their distal tips that resembles the apical ectodermal ridge (AER) and this thickened distal apical ectoderm expresses the AER-characteristic homeobox-containing gene Msx-2. Like in normal limb buds, a population of highly proliferating cells which express the homeobox-containing gene Msx-1 are localized in the mesoderm directly subjacent to the thickened AER-like structures induced by IGF-I and insulin. However, the limb bud-like structures induced by IGF-I and insulin do not express sonic hedgehog, which encodes a secreted signaling molecule that has been implicated in regulating the anteroposterior patterning of the developing limb bud. IGF-I- and insulin-treated prospective limb explants give rise to rudimentary limbs containing identifiable skeletal elements when grafted into the coelom or to somites of host embryos. Overall, these results suggest that IGF-I and insulin may be endogenous signals produced by medial tissues that are involved in conferring limb-forming ability to the lateral plate and may promote the initial outgrowth of limb buds and possibly induce the AER. However, other signals are necessary to promote the expression of genes such as sonic hedgehog that regulate the patterning of the developing limb. SN - 0012-1606 UR - https://www.unboundmedicine.com/medline/citation/8660895/IGF_I_and_insulin_in_the_acquisition_of_limb_forming_ability_by_the_embryonic_lateral_plate_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0012-1606(96)90163-3 DB - PRIME DP - Unbound Medicine ER -