Normal skeletal development of mice lacking matrilin 1: redundant function of matrilins in cartilage?
Matrilin 1, or cartilage matrix protein, is a member of a novel family of extracellular matrix proteins. To date, four members of the family have been identified, but their biological role is unknown. Matrilin 1 and matrilin 3 are expressed in cartilage, while matrilin 2 and matrilin 4 are present in many tissues. Here we describe the generation and analysis of mice carrying a null mutation in the Crtm gene encoding matrilin 1. Anatomical and histological studies demonstrated normal development of homozygous mutant mice. Northern blot and biochemical analyses show no compensatory up-regulation of matrilin 2 or 3 in the cartilage of knockout mice. Although matrilin 1 interacts with the collagen II and aggrecan networks of cartilage, suggesting that it may play a role in cartilage tissue organization, studies of collagen extractability indicated that collagen fibril maturation and covalent cross-linking were unaffected by the absence of matrilin 1. Ultrastructural analysis did not reveal any abnormalities of matrix organization. These data suggest that matrilin 1 is not critically required for cartilage structure and function and that matrilin 1 and matrilin 3 may have functionally redundant roles.
Aszódi
A
A
Department of Experimental Pathology, Lund University, 221 85 Lund, Sweden. attila.aszodi@pat.lu.se
Bateman
J F
JF
Hirsch
E
E
Baranyi
M
M
Hunziker
E B
EB
Hauser
N
N
Bösze
Z
Z
Fässler
R
R
D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology*; D002356:Cartilage / Q000737:chemistry / Q000254:growth & development*; D004838:Epiphyses / Q000737:chemistry; D016326:Extracellular Matrix Proteins / Q000172:deficiency* / Q000302:isolation & purification; D006023:Glycoproteins / Q000172:deficiency* / Q000302:isolation & purification; D006720:Homozygote; D007150:Immunohistochemistry; D064235:Matrilin Proteins; D051379:Mice; D008817:Mice, Mutant Strains; D013977:Tibia / Q000033:anatomy & histology; D014018:Tissue Distribution; D014132:Trachea / Q000737:chemistry
D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; C577540:Matn1 protein, mouse; C577542:Matn2 protein, mouse; C577546:Matn3 protein, mouse; D064235:Matrilin Proteins