Related Experiment Video
Updated: Feb 13, 2026
Simulating the Mechanics of Lens Accommodation via a Manual Lens Stretcher
Published on: February 23, 2018
Type VII Collagen in the Human Accommodation System: Expression in Ciliary Body, Zonules, and Lens Capsule
Bart Wullink1,2, Hendri H Pas3, Roelofje J Van der Worp1,2
1Department of Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Purpose:
To investigate intraocular expression of COL7A1 and its protein product type VII collagen, particularly at the accommodation system.
Methods:
Eyes from 26 human adult donors were used. COL7A1 expression was analyzed in ex vivo ciliary epithelium by microarray. Type VII collagen distribution was examined by Western blot analysis, immunohistochemistry. and immuno-electron microscopy.
Results:
COL7A1 is expressed by pigmented and nonpigmented ciliary epithelia. Type VII collagen is distributed particularly at the strained parts of the accommodation system. Type VII collagen was associated with various basement membranes and with ciliary zonules. Anchoring fibrils were not visualized.
Conclusions:
Type VII collagen distribution at strained areas suggests a supporting role in tissue integrity.
Related Concept Videos
01:05Type IV Collagen of Basal Lamina
A type IV collagen molecule has six alpha chains which can...
01:28Role of Proteins in the Human Body
01:25Dysrhythmias VII: Nursing Management of Dysrhythmias
01:05Mechanism of Ciliary Motion
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
01:18Structural Organization of the Human Body: An Overview
To study the chemical level of organization, scientists consider the simplest building blocks of matter: subatomic particles, atoms, and molecules. All matter in the universe is composed of one or more unique pure substances called elements, familiar examples of...
01:31Lipid-derived Compounds in the Human Body
Fat-soluble Vitamins
Fat-soluble vitamins, including vitamins A, D, E, and K, are required in minimal quantities, but their deficiencies can lead to severely abnormal physiological conditions. For example, vitamin A deficiency can cause night blindness, dry skin,...