Linked Life Data

15051472

Source:http://linkedlifedata.com/resource/pubmed/id/15051472

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2004-3-30
pubmed:abstractText
In the latter stages of development, the embryonic avian cornea undergoes significant changes in structure, composition and transparency. The rearrangement of stromal collagen fibrils at this time is important because it is believed to play a key role in the acquisition of corneal transparency. Here, we investigate spatial alterations in the internal fine structure of the avian cornea during development. Chicken corneas at developmental days 14, 16 and 18 were examined by transmission electron microscopy and quantitative image analysis. For anterior and posterior regions we determined fibril number densities, two-dimensional distribution functions, and, where appropriate, radial distribution functions. Stromal collagen fibrils became more closely spaced over the developmental range studied here. Changes in fibril number density indicated that fibrils became compacted first in the anterior stroma, and later (i.e. after day 16) in the posterior stroma. By day 18 collagen fibril number densities were essentially the same in superficial and deep tissue regions. At day 14, two-dimensional distribution functions of collagen fibrils in the posterior stroma pointed to a fibrillar array that was unlike that in the anterior stroma because there was no clear radial symmetry. Rather, in the deep stroma at day 14 there was evidence of different nearest neighbour spacings in two orthogonal directions. By day 18, fibril distributions in the anterior and posterior stroma were spatially homogeneous and radially symmetric, with radial distribution functions typical of those ordinarily found in mature cornea. Corneal transparency requires the stromal matrix to have some degree of regularity in the arrangement of its uniformly thin collagen fibrils. The chicken cornea becomes progressively transparent between days 14 and 18 of development as the stroma dehydrates and thins. We show that over this time period collagen fibrils in the anterior stroma become configured in advance of fibrils in deeper stromal regions, leading to questions over the potential roles of sulphated proteoglycans in different regions of the corneal stroma during morphogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-4835
pubmed:author
pubmed:issnType
Print
pubmed:volume
78
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
909-15
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Spatial and temporal alterations in the collagen fibrillar array during the onset of transparency in the avian cornea.
pubmed:affiliation
Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't