WHAT IS lens fiber differentiation?
Lens fiber cell differentiation is characterized by cell elongation, and temporally and spatially controlled expression of crystallins and other lens-specific proteins (Piatigorsky, 1981 ; Graw, 2003 ; Cvekl and Duncan, 2007 ).
Where do the lens epithelial cells differentiate into lens fibers?
Cells in the anterior segment of the lens vesicle differentiate to form the lens epithelium, while those in the posterior segment of the lens vesicle elongate towards the anterior, filling the lens vesicle lumen and are called primary lens fiber cells (Figure 2F).
WHAT IS lens differentiation?
Thus, all the lens epithelial cells are competent to undergo differentiation into lens fibre cells (including nuclear degradation) in response to diffusible factors produced by the retina acting on the posterior of the developing lens.
Do lens cells have nuclei?
lens fiber cells lose their nuclei, mitochondria, and other membrane-bound organelles. In the present study, a slice preparation of the embryonic chicken lens was used with laser scanning confo- cal microscopy to study the spatial and temporal patterns of organelle breakdown during embry- onic development.
What is the lens nucleus?
The lens nucleus contains proteins that are present from birth. Moreover, the outer fibrous cells no longer make proteins after the lens has been fully shaped (Zhang et al., 2008 and references therein). Formation of a dehydroalanyl (DHA) residue in proteins and peptides followed by irreversible glutathionylation.
How are lens fibers formed?
New lens fibers are generated from the equatorial cells of the lens epithelium, in a region referred to as the germinative zone. The lens epithelial cells elongate, lose contact with the capsule and epithelium, synthesize crystallin, and then finally lose their nuclei (enucleate) as they become mature lens fibers.
What structure gives rise to the lens fibers?
Surface ectoderm forms the lens, corneal epithelium and eyelid. The extracellular mesenchyme forms the sclera, the corneal endothelium and stroma, blood vessels, muscles, and vitreous.
What is a lens cell?
Abstract. Lens cells originate from the head ectoderm and differentiate into an avascular organ constituted from two contiguous cell subpopulations of very different morphology. Lens cells, together with corneal cells, are responsible for the transmission and focusing of light onto the retina.
Do lens cells have mitochondria?
Mitochondria are abundant in the lens, but only within the epithelium and differentiating fibers, as mature fibers in the core of the lens lack mitochondria.
