UNLABELLED: Some mucin genes have been detected during human embryonic and fetal organ development; however, little is known about mucin expression in epidermal development, neither in humans nor in other species. The present research was developed to explore Muc5ac skin expression during prenatal and postnatal rat development. Immunohistochemistry (IHC), Western blotting (WB) and RT-PCR were employed. By IHC, Muc5ac protein was found early in embryonic epidermis from day 13 of gestation until seven days after birth when the surface epidermis became negative and the reaction was restricted to secreting sebum cells. In coincidence with IHC findings, WB analysis showed a band at approximately 200KDa at the same periods of development. Results were also confirmed by RT-PCR. Muc5ac expression in rat embryonic epidermis suggests that Muc5ac may play a protective role in embryonic skin previous to birth which may be replaced by pile covering. To our knowledge, this is the first report which confirmed Muc5ac expression during skin development.CONCLUSION:   Muc5ac expression in rat embryonic epidermis suggests that Muc5ac may play a protective role in embryonic skin previous to birth which may be replaced by pile covering. To our knowledge, this is the first report which confirmed Muc5ac expression during skin development.
Animals Electrophoresis, Polyacrylamide Gel