dysmorphology screen

http://www.helmholtz-muenchen.de/en/ieg/group-functional-genetics/bonecartilage/index.html

The Dysmorphology, Bone and Cartilage Screen of the GMC contributes the phenotyping for bone and cartilage related phenotypes as well as for morphological abnormalities. The aim of the screen is to establish mouse models for human skeletal diseases like osteoporosis, scoliosis, limb defects, osteogenesis imperfecta or osteoarthritis.

For the primary screen, we cover a broad spectrum of parameters of bone development, bone metabolism and homeostasis. We have implemented an experimental set up, which enables us to perform high throughput non-invasive first-line phenotyping for bone and cartilage abnormalities. In addition, we developed a protocol (54 parameters) for a quick anatomical observation of animals, which is able to detect and evaluate malformations and malfunctions of the different organ systems.

1. Dysmorphological Analysis:

• Quick and easy whole body check up for anatomical abnormalities and malfunctions in different organ systems (e.g. assessment of hearing by clickbox-test).
  

2. X-ray Analysis:

• Within a few minutes the whole mouse skeleton can be visualised, X-rays of special parts can be obtained in higher magnification.
• Judgments of the appearance and presence of all bones and joints can be made.
• Information about developmental disorders and to a minor extent bone metabolic disorders.

3. Bone densitometry:

• Measurement of bone density and body composition rapidly and quantitatively.
• Information about bone mineralization and homeostasis defects (e.g. osteoporosis, osteogenesis imperfecta).

In secondary tests, we evaluate mutants with altered parameters in the primary screen for the use as model systems for human bone related diseases like scoliosis, limb defects, osteoporosis, osteogenesis imperfecta or osteoarthritis by more detailed phenotypic characterisation.

1. pQCT (peripheral quantitative computed tomography):

• Enables volumetric bone density measurements in g/cm3 of the appendicular skeleton and tail vertebra (in vivo).
• Separates cortical and trabecular bone compartements (BMD, BMC).

2. µCT (micro computed tomography):

• Helps to obtain a better view of the abnormality (in vivo and in vitro).
• In vivo imaging with a resolution between 30 and 60 microns.
• In vitro resolution down to 12 microns.
• 2D sectional analysis of the organ of choice.
• Digital processing creates a 3-D picture.

3. Markers of bone turnover/metabolism and hormonal regulation:

• The purpose is to identify mutants of systemic metabolic bone diseases quickly and non-invasively.
• Bone formation and hormonal markers are usually measured in serum, markers of bone resorption are typically measured in urine.
  

4. Mechanical bending: three-point bend test:

• Measurement of plastic and elastic stability or fracture parameters of bones.

5. Skeleton preparation:

• Staining with alcian blue (cartilage) and alizarin red (bone)

We are using standardised and validated protocols established by the EUMORPHIAConsortium (http://www.eumorphia.org/). With our work, we contributed to the development of bone phenotyping protocols. Individual standard operating procedures (SOPs) for phenotyping are available on the European Mouse Phenotyping Resource of Standardised Screens (EMPReSS): http://www.empress.har.mrc.ac.uk/

1. Fuchs H, Schughart K, Wolf E, Balling R, Hrabé de Angelis M.
   Screening for dysmorphological abnormalities - a powerful tool to isolate new mouse mutants. Mamm Genome. 2000 Jul;11(7):528-30.
2. Helmut Fuchs, Thomas Lisse, Koichiro Abe and Martin Hrabé de Angelis 2006: Screening for bone and cartilage phenotypes in mice. In Phenotyping of the Laboratory Mouse. Eds.: Hrabé de Angelis M., Chambon P. and Browns S. Wiley-VCH, Weinheim, in Press.
3. Vreugde S, Erven A, Kros CJ, Marcotti W, Fuchs H, Kurima K, Wilcox ER, Friedman TB, Griffith AJ, Balling R, Hrabé de Angelis M, Avraham KB, Steel KP.
   Beethoven, a mouse model for dominant, progressive hearing loss DFNA36. Nat Genet. 2002 Mar;30(3):257-8. Epub 2002 Feb 19.
4. Hafezparast M, Klocke R, Ruhrberg C, Marquardt A, Ahmad-Annuar A, Bowen S, Lalli G, Witherden AS, Hummerich H, Nicholson S, Morgan PJ, Oozageer R, Priestley JV, Averill S, King VR, Ball S, Peters J, Toda T, Yamamoto A, Hiraoka Y, Augustin M, Korthaus D, Wattler S, Wabnitz P, Dickneite C, Lampel S, Boehme F, Peraus G, Popp A, Rudelius M, Schlegel J, Fuchs H, Hrabé de Angelis M, Schiavo G, Shima DT, Russ AP, Stumm G, Martin JE, Fisher EM.
   Mutations in dynein link motor neuron degeneration to defects in retrograde transport. Science. 2003 May 2;300(5620):808-12.