4235 PAX6-gene expression during human embryonic development at the cellular level

Srreesr; To analyze cytoskeletal development in neuroectodermally derived epithelial and muscle cells of the human eye during the 2nd and 3rd trimesters of pregnancy. M&c& Nine formalin-fured and paraffin-embedded autopsy eyes representing the 13th to 49th week of gestation were studied with 10 monoclonal antibodies (MAbs) to intermediate filaments and ,x-smooth muscle actin (&MA) using the avidin-biotinylated pcroxidasc complex (ABC) method. &&.tg The q&he&s of rhe iris reacted with MAbs Vim 384 and V9 to vimentin in all specimens. Reactivity with MAb CAM 5.2 to CK 8 and MAbs CY-90 and KS-B17.2 to CK 18 disappeared from its anterior and posterior layer by the 18th and 28th gestational week, respectively. The whole anterior layer reacted with MAb lA4 to c&MA from the 28th week onward. MAbs DEU-10 and D33 to desmin lab&d its dilarorfibcrs by the 37th week, and focal reactivity for CK 8 and 18 concurrently appeared in them. The future iris sphincrer reacted for oSMA in all eyes. In the earliest specimens, this reactivity was still confined to cells of the rilag sinus. The initial reactivity of tbe sphincter for vimentin gradually disappeared after the 22nd week, whereas MAbs to desmin increasingly labeled it from the 18th week onward. MAbs to vimentin, CK 8 and CK 18 labelled tbe ciliary epithdium in all specimens. The ciky mr&e reacted for vimentin and uSMA in all eyes studied, and from the 16th week onward increasingly strong immunoreactivity for desmin’ was present in it. The ret&l pigmeM epithelium reacted with MAbs to vimentin, CK 8 and CK 18 throughout the fetal period studied. ~&B&&B The results highlight the highly individual cytoskeletal development of tbe derivatives of the optic vcsiclc, and offer a framework for detccting pathological changes in the neuroectcdermal cytoskeleton of the fetal, human eye after the fmt trimester of pregnancy. NADPH DIAPHORASE REACTIVITY OF THE RABBIT