IMMUNOHISTOCHEMICAL ANALYSIS OF RAT MUC1 EPITHELIAL MUCIN DURING DEVELOPMENT: TEMPORAL EXPRESSION AND TISSUE SPECIFIC LOCALIZATION

V FERRETTI; E LACUNZA; BARBEITO C; SEGAL-EIRAS A; CROCE MV

Buenos Aires

Jornada; Sociedad Argentina de Biología; 2008

SAB

Introduction: The MUC1/Muc1 mucin (MUC1 in humans andMuc1 in others species) is a high molecular weight transmembraneglycoprotein expressed at the apical surface of most epithelia. Ithas been established that MUC1 expression coincides with the onsetof epithelial sheet and glandular formation during embryonicdevelopment. Objective: To analyze Muc1 expression and tissuespecific localization in different embryonic stages of the rat. Methodology:a total of 8 embryos of each gestational stage (13 to 20days of gestation), 8 neonates and 8 adults were included. By Immunohistochemistry,employing the anti-MUC1 CT33 antibody, thefollowing tissues were analyzed: esophagus, stomach, small intestine,salivary gland, liver, pancreas, trachea, lung and kidney.. Results:Muc1 expression was observed in the stomach, lung and kidneyat the gestational age of 13 days (D13). In embryonic pancreas,Muc1 expression appeared at D14 stage. In small intestine, a strongreaction was observed from D15 while esophagus and tracheashowed expression from D18. In all cases, the reaction was restrictedto epithelial cells with a predominantly apical pattern. Inthe liver, a positive reaction was detected from D16, being the onlyorgan analyzed which showed a cytoplasmic pattern. The ducts ofthe salivary glands showed reaction from D18 with an apical pattern;at D20, mucous and serous acini were distinguished and Muc1expression was detected. Discussion: In several of the organsanalysed, rat Muc1 mucin was expressed in coincidence with epithelialdifferentiation which may suggest a possible role of thismucin during epithelia formation.