Phenotype Image Detail

Image

Caption

Ossification of medial collateral ligament in Bmal1^tm1Bra/Bmal1^tm1Bra mice is progressive. a,b: Lateral radiograph of stifle joint femur extending to the top and tibia towards the bottom. a: Wild-type mouse at 35-weeks of age. b: Bmal1^tm1Bra/Bmal1^tm1Bra mouse at 35-weeks of age. Note mineralized tissue extending from patella and the medial collateral ligament insertion sites (b, white arrows). Safranin O and Fast green stained 10 um sections (c-k). c: Normal stifle anatomy in 26-week old wild-type mouse oriented with medial collateral ligament (MCL) to the left and the distal femur on top. d: Stifle anatomy in 26-week old mutant noting the increase in glycosaminoglycan staining within the MCL (arrow) and cruciate ligaments (asterisk), magnification 2x. e: Stifle anatomy of a 35-week old mutant noting increased glycosaminoglycan staining in ligaments (asterisk) and large osteophyte formation centering on the MCL insertion site (arrow), magnification 2x. Ossification extends along the length of the MCL and large areas of chondrification are present in cruciate ligaments. f: Enlargement of the MCL insertion in 26-week old wild-type mouse clearly showing the transition of fibrous ligament (lavender color stain), to fibrocartilage (chondrocytes in red-colored lacunae), to woven bone (blue stain). g: Enlargement of MCL insertion of 26-week mutant mice, noting the development and proliferation of a perichondrium (open arrowhead), increased red glycosaminoglycan staining in fibrous ligament tissue, and strong tidemark delineating bone formation (filled arrowhead). h: Large osteophyte containing areas of chondrification (red stain) and ossification (blue stain with purple marrow) located at the MCL insertion of 35-week old mutant mice, 10x magnification. i: 20x magnification of the MCL insertion site in 35-week old mutant mice noting amorphous calcium deposits (open arrowhead), strong tidemark delineating bone from heterotopic cartilage formation (closed arrowhead), and the appearance of chondrocytes within distinct lacunae where there was formerly dense regular connective tissue (arrow). j,k: Articular cartilage depth and morphology are indistinct between wild-type (j) and mutant mice (k).

Copyright

This image is from Bunger MK, Genesis 2005 Mar;41(3):122-32, and is displayed with the permission of Wiley-Blackwell, who owns the Copyright. J:97108

Associated Alleles

Symbol	Name
Bmal1^tm1Bra	basic helix-loop-helix ARNT like 1; targeted mutation 1, Christopher A Bradfield

Associated Genotypes

Allelic Composition	Genetic Background
Bmal1^tm1Bra/Bmal1^tm1Bra	B6.129-Bmal1^tm1Bra