REGIONAL GLYCOPROTEIN EXPRESSION IN THE CHICKEN LENS

Purpose. Several previous studies have shown that glycoconjugates of e xtracellular matrix, cell membrane and nucleus play an important role in the mediation of cell proliferation, migration and differentiation. Lens epithelial cells and lens fiber cells show regional differences with regard to these parameters. If glycoconjugates participate in the regulation of these patterns in the lens, there should be regional di fferences in the expression of glycoconjugates. The investigation was focused on the anterior pole, equator and nuclear bow regions, which d iffer extensively in lens cell proliferation and differentiation. Meth ods. To check this hypothesis, the regional binding pat tern of twelve different FITC-conjugated lectins was studied glycohistochemically, u sing paraffin embedded material. The investigation was focused on the anterior pole, equator and nuclear bow regions. Results. Regional diff erences in lectin binding patterns were identified in the lens capsule , epithelium and the nuclear bow regions. The lens capsule was fluores cently labeled with GS-I, UEA-I, LPA, MAA, SNA only at the anterior po le and with CON-A, WGA, DBA, SEA only at the equator. Staining of the entire anterior surface of the lens capsule was observed with LFA. Cel l membranes of the lens epithelium showed binding of MAA and LFA only at the equator. LFA, LPA, MAA and SNA only stained the nuclei of fiber cells at the nuclear bow region but not of lens epithelial cells. WGA strongly labeled the nuclei of equatorial epithelial cells and fiber cells at the bow region. Conclusions. It is assumed that the observed regional variations in glycoprotein expression in the extracellular ma trix and lens cells contribute to the regulation of cell behavior in d ifferent areas of the lens.