Neonatal development of the corneal stroma in wild-type and lumican-null mice.
OBJECTIVE
Between days 8 and 14 of neonatal development, the corneal stroma of the mouse undergoes critical changes in tissue thickness, cell density, and light scattering. The authors investigate the stromal matrix structure in wild-type and lumican-deficient corneas in this developmental phase.


METHODS
Wild-type (n = 44) and lumican-deficient (n = 42) mouse corneas at neonatal days 8, 10, 12, and 14 were investigated by synchrotron x-ray diffraction to establish the average collagen fibril spacing, average collagen fibril diameter, and level of fibrillar organization in the stromal matrix.


RESULTS
Collagen interfibrillar spacing in the normal mouse cornea became more closely packed between days 8 and 14, though not significantly so. In lumican-null mice, interfibrillar spacing was significantly elevated at days 8, 10, and 12, but not day 14, compared with that in wild-type mice. At all stages investigated, collagen fibrils were, on average, marginally thinner than normal in lumican-null mutants, and the spatial distribution of the fibrils was less well organized.


CONCLUSIONS
Transient thickening of the corneal stroma of the normal mouse at eye opening is probably not caused by widespread, homogeneous rearrangement of collagen fibrils but more likely by a temporary increase in cell or stromal "lake" volume. Lumican, structurally influential in adult mouse corneas, is also a key molecule in the neonatal development of the stromal matrix.
Beecher
Nicola
N
Structural Biophysics Group, Cardiff School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom.
Chakravarti
Shukti
S
Joyce
Sarah
S
Meek
Keith M
KM
Quantock
Andrew J
AJ
D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D011508:Chondroitin Sulfate Proteoglycans / Q000172:deficiency / Q000502:physiology*; D003319:Corneal Stroma / Q000254:growth & development* / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D024022:Fibrillar Collagens / Q000378:metabolism; D007632:Keratan Sulfate / Q000172:deficiency / Q000502:physiology*; D000071234:Lumican; D051379:Mice; D014961:X-Ray Diffraction
D011508:Chondroitin Sulfate Proteoglycans; D024022:Fibrillar Collagens; C000604307:Lum protein, mouse; D000071234:Lumican; D007632:Keratan Sulfate