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Restoration of normal bone development by human homologue of collagen type II (COL2A1) gene in Col2a1 null mice
Author(s) -
Rani Pyapalli U.,
Stringa Emanuela,
Dharmavaram Rita,
Chatterjee Devjani,
Tuan Rocky S.,
Khillan Jaspal S.
Publication year - 1999
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/(sici)1097-0177(199901)214:1<26::aid-dvdy3>3.0.co;2-v
Subject(s) - endochondral ossification , biology , cartilage , type ii collagen , transgene , phenotype , microbiology and biotechnology , gene , genetically modified mouse , gene targeting , mutant , type i collagen , collagen, type i, alpha 1 , genetics , extracellular matrix , anatomy , endocrinology
Development of the vertebrate skeleton is a highly complex process in which collagen type II plays a vital role in the formation of long bones via endochondral ossification. Collagen type II, which is encoded by a single COL2A1/Col2a1 gene, is the most abundant structural protein in the cartilage matrix, where it undergoes complex interactions with several other proteins. The sequence of mature collagen type II chains, each with about 1,100 amino acids, is conserved between different mammalian species. There are 37 amino acid positions that are different between mouse and human collagen type II. Previously, we have demonstrated that transgenic mice, in which Col2a1 gene is knocked out, exhibit a lethal phenotype due to the absence of endochondral bone formation. To investigate whether the biological role of collagen type II is conserved between the species, human COL2A1 gene was expressed in Col2a1 null mice by crossing with transgenic mice in which human COL2A1 gene was integrated. The collagen type II from human gene rescued the lethal phenotype in null mice, indicating that the biological function of collagen type II is conserved between human and mouse. The animals exhibited normal endochondral bone formation and a normal growth plate in tibio‐tarsal joint. Chondrocytes isolated from the cartilage of these mice secreted human protein, suggesting that the animals incorporated heterologous protein to form cartilage which is essentially “humanized.” The animals reached puberty and produced normal progeny. A completely normal phenotype in newborns indicates that human COL2A1 gene is expressed properly both temporally and spatially. These animals may be useful to generate models to study the effect of COL2A1 mutations on skeletal development in humans by introducing mutated gene constructs either into embryos or by crossing with transgenic animals with COL2A1 mutations. Dev Dyn 1999;214:26–33 . © 1999 Wiley‐Liss, Inc.