title: The stratified syncytium of the vertebrate lens.
abstract: The fusion of cells to generate syncytial tissues is a crucial event in the development of many organisms. In the lens of the vertebrate eye, proteins and other macromolecules diffuse from cell to cell via the large molecule diffusion pathway (LMDP). We used the tamoxifen-induced expression of GFP to investigate the nature and role of the LMDP in living, intact lenses. Our data indicate that the LMPD preferentially connects cells lying within a stratum of the lens cortex and that formation of the LMPD depends on the expression of Lim2, a claudin-like molecule. The conduits for intercellular protein exchange are most likely regions of partial cellular fusion, which are commonly observed in wild-type lenses but rare or absent in Lim2-deficient lenses. The observation that lens tissue constitutes a stratified syncytium has implications for the transparency, refractive function and pathophysiology of the tissue.
authors.affiliation: Department of Ophthalmology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA.
authors.forename: Yanrong
authors.initials: Y
authors.lastname: Shi
authors.forename: Kelly
authors.initials: K
authors.lastname: Barton
authors.forename: Alicia
authors.initials: A
authors.lastname: De Maria
authors.forename: J Mark
authors.initials: JM
authors.lastname: Petrash
authors.forename: Alan
authors.initials: A
authors.lastname: Shiels
authors.forename: Steven
authors.initials: S
authors.lastname: Bassnett
mesh_terms: D000818:Animals; D002450:Cell Communication; D002454:Cell Differentiation; D002459:Cell Fusion; D049109:Cell Proliferation; D016922:Cellular Senescence; D004058:Diffusion; D020847:Estrogen Receptor Modulators / Q000494:pharmacology; D005136:Eye Proteins / Q000378:metabolism; D015726:Giant Cells / Q000166:cytology / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D019426:Integrases / Q000235:genetics; D007908:Lens, Crystalline / Q000166:cytology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D011960:Receptors, Estrogen / Q000187:drug effects / Q000235:genetics; D013050:Spectrometry, Fluorescence; D013629:Tamoxifen / Q000494:pharmacology; D046888:Tissue Array Analysis; D014054:Tomography
chemical_list: D020847:Estrogen Receptor Modulators; D005136:Eye Proteins; C489025:Lim2 protein, mouse; D008562:Membrane Glycoproteins; D011960:Receptors, Estrogen; D013629:Tamoxifen; D049452:Green Fluorescent Proteins; C045073:Cre recombinase; D019426:Integrases