Immunocytochemical study on the triple origin of the sphincter iris in the chick embryo

Abstract

The ontogenic development of the sphincter iris has been studied by immunocytochemistry and standard staining on chick embryos from stage 25 HH to the time of hatching. We have used the monoclonal antibody 13F4, a highly specific marker of muscular cells. We have observed three different regions in the iris. In the pupillary region, immunoreactive cells are in continuous contact with the inner epithelium of the pupillary margin. In the intermediate region, the outer epithelium forms buds of pigmented cells that emigrate toward the stroma. In this epithelium cells that are totally or partially unpigmented exist, and they are 13F4 positive. In the sphincter we have observed 13F4 positive cells with melanin granules. In the ciliary region, the immunoreactivity appears in dispersed mesenchymal cells. The present findings are consistent with a triple origin of the sphincter iris in the chick embryo. This muscle is derived from the inner epithelium of the pupillary margin, the intermediate region of the outer epithelium, and from the mesenchymal cells. The cells of the inner epithelium of the pupillary margin are differentiated into smooth muscle cells, and the remaining cells form striated muscle cells.

Neural crest derivatives in ocular and periocular structures

“…5 A-C). These cells therefore were not derived from the pigmented OV epithelium, as previously proposed by Barrio-Asensio and coworkers (Barrio-Asensio et al, 1999;Barrio-Asensio et al, 2002). …”

The Homeobox Gene Six3 Is a Potential Regulator of Anterior Segment Formation in the Chick Eye

“…7E and 7F), even though the similar staining intensity remained in the residual Pax6-positive iris stromal cells. Furthermore, a muscle-specific marker (monoclonal antibody 13F4) (Rong et al, 1987;Barrio-Asensio et al, 1999) also revealed abnormal iris muscle organization in Six3 virus-infected eyes compared with the control virus-infected eye (Figs. 7G and 7H).…”

“…2E and 2F). The anti-Pax6 (Ericson et al, 1997), anti-type IX collagen (2C2; Irwin et al, 1985;Fitch et al, 1988), anti-keratan sulfate (I22;Funderbergh et al, 1982Funderbergh et al, , 1986, anti-muscle cell specific antigen (13F4; Rong et al, 1987;Barrio-Asensio et al, 1999), and the anti-viral GAG protein (3C2; Stoker and Bissell, 1987) monoclonal antibodies were obtained from the Developmental Studies Hybrid-oma Bank (DSHB, Iowa City). The polyclonal antibodies p27 against the viral GAG protein were purchased from SPAFAS.…”

The pupillary light responses of animals; a review of their distribution, dynamics, mechanisms and functions

“…Classically, the iris muscles are described as unstriated in mammals, fish, and amphibia, but striated in birds and reptiles. However, both pharmacological and histological work suggests the irises of some reptiles (Iske, 1929;Reger, 1966) and many birds in fact contain both striated and non-striated muscle components (Gabella & Clarke, 1983;Yamashita & Sohal, 1986;Scapolo et al, 1988;Barrio-Asensio et al, 1999;Loerzel et al, 2002). Although the non-striated tissue can be located throughout the iris in smooth muscle cells within the stroma, it often forms a distinct myoepithelial dilator muscle (Walls 1942 for review of earlier literature; van Oehme, 1969;Nishida & Sears, 1970;Oliphant et al, 1983;Dieterich et al, 1988).…”