Optimization of Volumetric Computed Tomography for Skeletal Analysis of Model Genetic Organisms

Vasquez, Sergio X.; Hansen, Mark; Bahadur, Ali; Hockin, Matthew F.; Kindlmann, Gordon; Nevell, Lisa; Wu, Isabel Q.; Grunwald, David J.; Weinstein, David M.; Jones, Greg; Johnson, Christopher R.; VandeBerg, John L.; Capecchi, Mario R.; Keller, Charles

doi:10.1002/ar.20670

Cited by 25 publications

(15 citation statements)

References 66 publications

(52 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…X-ray microtomography (microCT) is already widely used in studies of mineralized tissues (e.g., Neues et al, 2007;Stauber and Mü ller, 2008;Vasquez et al, 2008), and it has been effectively used in quantitative studies of variation (Hallgrimsson et al, 2007) and of development (Parsons et al, 2008). The applications of other tomographic methods, particularly micro-MRI (Jacobs et al, 2003;Ruffins et al, 2007) and optical projection tomography (Kerwin et al, 2004;Sharpe, 2004), have been demonstrated convincingly, but the use of X-ray-based tomographic imaging has been constrained by the low intrinsic X-ray absorption of unmineralized tissue and the lack of established contrast agents.…”

Section: Introductionmentioning

confidence: 99%

MicroCT for developmental biology: A versatile tool for high‐contrast 3D imaging at histological resolutions

Metscher

2009

Developmental Dynamics

533

624

View full text Add to dashboard Cite

Understanding developmental processes requires accurate visualization and parameterization of threedimensional embryos. Tomographic imaging methods offer automatically aligned and calibrated volumetric images, but the usefulness of X-ray CT imaging for developmental biology has been limited by the low inherent contrast of embryonic tissues. Here, I demonstrate simple staining methods that allow high-contrast imaging of embryonic tissues at histological resolutions using a commercial microCT system. Quantitative comparisons of images of chick embryos treated with different contrast agents show that three very simple methods using inorganic iodine and phosphotungstic acid produce overall contrast and differential tissue contrast for X-ray imaging at least as high as that obtained with osmium. The stains can be used after any common fixation and after storage in aqueous or alcoholic media, and on a wide variety of species. These methods establish microCT imaging as a useful tool for comparative developmental studies, embryo phenotyping, and quantitative modeling of development. Developmental Dynamics 238: 632-640, 2009.

show abstract

Section: Introductionmentioning

confidence: 99%

MicroCT for developmental biology: A versatile tool for high‐contrast 3D imaging at histological resolutions

Metscher

2009

Developmental Dynamics

533

624

View full text Add to dashboard Cite

show abstract

“…Such systems have been used to investigate the anatomy of embryonic and newborn mice (Ahrens et al, 2006;Johnson et al, 2006;Kulandavelu et al, 2006;Oest et al, 2008). Specifically, high-resolution micro-CT systems have been utilized to study embryonic and fetal development (Guldberg et al, 2004) and fetuses of multiple species (Vasquez et al, 2008). Recently, highthroughput micro-CT has been used to evaluate fetal skeletal morphology in rats and rabbits (Winkelmann and Wise, 2009;Wise and Winkelmann, 2009a,b).…”

Section: The Future Of Developmental Toxicity Studiesmentioning

confidence: 98%

Embryo‐fetal developmental toxicity study design for pharmaceuticals

Wise

Buschmann

Feuston

et al. 2009

Birth Defects Research Pt B

View full text Add to dashboard Cite

Assessment of potential developmental and reproductive toxicity of human pharmaceuticals is currently guided by the International Conference on Harmonization (ICH) S5(R2) document (available at http://www.ich.org). The studies that assess developmental hazard are generally conducted in rodents and rabbits. Based on the authors' collective experience, adequate designs (including range-finding studies) and the presentation of data for these studies are described in detail. In addition, the suggested initiation and then total duration of these studies in relation to clinical studies that enroll women of childbearing potential are described. Optional parameters that may be included in the studies are discussed, as are study designs that combine assessments of fertility and developmental toxicity. New methods that may replace or enhance current procedures are outlined. The details described herein will assist all laboratories performing these studies, individuals who need to plan for the studies, and regulatory agencies that ultimately review these studies.

show abstract

“…The data that was obtained was analyzed using MicroView (open source software from GE). Using this software the femurs were first separated from the total scans and the volumetric bone mineral density (BMD) of whole femurs from the Pten conditional knockouts were compared with the wild-type controls from postnatal day one (Vasquez et al, 2008).…”

Section: Microctmentioning

confidence: 99%

Conditional ablation of Pten in osteoprogenitors stimulates FGF signaling

et al. 2011

View full text Add to dashboard Cite

SUMMARYPhosphatase and tensin homolog deleted on chromosome ten (PTEN) is a direct antagonist of phosphatidylinositol 3 kinase. Pten is a well recognized tumor suppressor and is one of the most commonly mutated genes in human malignancies. More recent studies of development and stem cell behavior have shown that PTEN regulates the growth and differentiation of progenitor cells. Significantly, PTEN is found in osteoprogenitor cells that give rise to bone-forming osteoblasts; however, the role of PTEN in bone development is incompletely understood. To define how PTEN functions in osteoprogenitors during bone development, we conditionally deleted Pten in mice using the cre-deleter strain Dermo1cre, which targets undifferentiated mesenchyme destined to form bone. Deletion of Pten in osteoprogenitor cells led to increased numbers of osteoblasts and expanded bone matrix. Significantly, osteoblast development and synthesis of osteoid in the nascent bone collar was uncoupled from the usual tight linkage to chondrocyte differentiation in the epiphyseal growth plate. The expansion of osteoblasts and osteoprogenitors was found to be due to augmented FGF signaling as evidenced by (1) increased expression of FGF18, a potent osteoblast mitogen, and (2) decreased expression of SPRY2, a repressor of FGF signaling. The differentiation of osteoblasts was autonomous from the growth plate chondrocytes and was correlated with an increase in the protein levels of GLI2, a transcription factor that is a major mediator of hedgehog signaling. We provide evidence that increased GLI2 activity is also a consequence of increased FGF signaling through downstream events requiring mitogen-activated protein kinases. To test whether FGF signaling is required for the effects of Pten deletion, we deleted one allele of fibroblast growth factor receptor 2 (FGFR2). Significantly, deletion of FGFR2 caused a partial rescue of the Pten-null phenotype. This study identifies activated FGF signaling as the major mediator of Pten deletion in osteoprogenitors.

show abstract

Optimization of Volumetric Computed Tomography for Skeletal Analysis of Model Genetic Organisms

Cited by 25 publications

References 66 publications

MicroCT for developmental biology: A versatile tool for high‐contrast 3D imaging at histological resolutions

MicroCT for developmental biology: A versatile tool for high‐contrast 3D imaging at histological resolutions

Embryo‐fetal developmental toxicity study design for pharmaceuticals

Conditional ablation of Pten in osteoprogenitors stimulates FGF signaling

Contact Info

Product

Resources

About