Temporal and Spatial Expression of Mucins MUC1 and MUC5AC during Rat Development

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

Santa Cruz, Chile

Congreso; V International Meeting of the Latin American Society for Developmental Biology; 2010

The transmembrane gycoprotein Muc1 is expressed at the apical surface of most adult epithelia while the Muc5AC is a secreted mucin which polymerizes on the epithelia cell surfaces forming a mucus gel. In adult tissues , Muc5AC is synthesized mainly by gastric and respiratory tissues. The objective of this research was to compare the pattern  expression and tissue specific localization of Muc1 and Muc5AC during rat embryonic development. A total of 8 fetuses of each gestational stage from 13 to 20 Days of Gestation (D13-D20), 8 neonates and 8 adults were included. Muc1 expression was found in several embryonic epithelia tissues being stomach, lung and kidney the first to show reaction on the 13 day of gestation (D13). The pattern of reaction was predominantly linear in the apical part of the cells. While Muc5AC expression was observed in lung and gastric epithelia; the intensity of reaction varied from low to strong; the expression was detected from D14 in lung tissue and from D17 in gastric epithelium. Interestingly, Muc5ac was detected in the epidermis from D13 to D20. Immunohistochemical results were validated by WB; by this technique, an increased expression of the mucin was observed which correlates with the development progress. Our results showed that Muc1 and Muc5AC expression depends on the time of development and also the tissue considered.