Related Experiment Video
Updated: Jul 20, 2026
09:16
Analyzing Craniofacial Morphogenesis in Zebrafish Using 4D Confocal Microscopy
Published on: January 30, 2014
Twisted gastrulation, a bone morphogenetic protein agonist/antagonist, is not required for post-natal skeletal
Elisabetta Gazzerro1, Valerie Deregowski, Lisa Stadmeyer
1Department of Research, Saint Francis Hospital and Medical Center, Hartford, CT 06105-1299, USA.
Bone
|August 29, 2006
Summary
Twisted gastrulation (Tsg) enhances bone morphogenetic protein (BMP) activity in osteoblasts. However, Tsg plays a minimal role in maintaining adult bone homeostasis in vivo.
Area of Science:
- Skeletal Biology
- Molecular Endocrinology
- Bone Physiology
Background:
- Twisted gastrulation (Tsg) is a secreted glycoprotein modulating bone morphogenetic protein (BMP) signaling.
- Tsg's role in adult bone homeostasis and osteoblast function remains largely unknown.
- Tsg exhibits context-dependent BMP agonist and antagonist activities.
Purpose of the Study:
- To investigate the in vivo and in vitro functions of Tsg in adult bone.
- To determine the consequences of Tsg deletion on skeletal development and osteoblast activity.
- To elucidate Tsg's role in BMP-mediated signaling within the bone microenvironment.
Main Methods:
- Generation and analysis of tsg null mice.
- Assessment of skeletal phenotypes, including bone volume and cellularity.
- In vitro studies using primary osteoblasts from tsg null and wild-type mice.
- RNA interference to down-regulate Tsg expression in osteoblasts.
Main Results:
- Tsg null mice exhibited a transient 40% decrease in trabecular bone volume at 4 weeks.
- Osteoblast and osteoclast numbers, bone formation, and resorption rates were unaffected.
- Tsg deficiency impaired BMP-2-stimulated osteocalcin expression and alkaline phosphatase activity in osteoblasts.
- Tsg null osteoblasts showed reduced BMP signaling, confirming Tsg's role in enhancing BMP activity.
Conclusions:
- Endogenous Tsg is essential for optimal BMP activity in osteoblastic cells in vitro.
- Tsg plays a minor role in the regulation of adult bone homeostasis in vivo.
- The transient skeletal phenotype suggests compensatory mechanisms in adult bone.
More Related Videos
12:59Three and Four-Dimensional Visualization and Analysis Approaches to Study Vertebrate Axial Elongation and Segmentation
Published on: February 28, 2021
06:49Analysis of Cell Differentiation, Morphogenesis, and Patterning During Chicken Embryogenesis Using the Soaked-Bead Assay
Published on: January 12, 2022
Related Concept Videos
01:31Bone Remodeling and Repair
Osteoclasts are cells responsible for bone resorption and remodeling. They originate from hematopoietic progenitor cells present in the bone marrow. Numerous progenitor cells fuse to form multinucleated cells, each with 10-20 nuclei. A single osteoclast has a diameter of 150 to 200 µM. These cells have ruffled borders that break down the underlying bone tissue and release minerals such as calcium into the blood in bone resorption. Osteoclasts cling to bones with their ruffled edges during bone...
01:56Gastrulation
Gastrulation establishes the three primary tissues of an embryo: the ectoderm, mesoderm, and endoderm. This developmental process relies on a series of intricate cellular movements, which in humans transforms a flat, “bilaminar disc” composed of two cell sheets into a three-tiered structure. In the resulting embryo, the endoderm serves as the bottom layer, and stacked directly above it is the intermediate mesoderm, and then the uppermost ectoderm. Respectively, these tissue strata will form...
01:29Bone Formation by Intramembranous Ossification
Intramembranous ossification is one of the two processes involved in the development of bones within an embryo. The flat bones of the face, most of the cranial bones, and the clavicles are formed via this process. During intramembranous ossification, the bones develop directly from sheets of undifferentiated mesenchymal connective tissue.
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...
01:40Bone Remodeling
Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.
01:24Bone Formation by Endochondral Ossification
Bone formation, or ossification, begins around the sixth to seventh week of embryonic development. Most bones develop from a cartilaginous template through the process of endochondral ossification. Cartilage formation begins when clusters of mesenchymal cells differentiate into chondrocytes. These chondrocytes proliferate rapidly and secrete an extracellular matrix that becomes encased in a membrane called the perichondrium. The resulting cartilage model provides a template that resembles the...
01:16TGF - β Signaling Pathway
The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...