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Spatial expression patterns of skin‐type antifreeze protein in winter flounder ( Pseudopleuronectes americanus ) epidermis following metamorphosis
Author(s) -
Murray Harry M.,
Hew Choy L.,
Fletcher Garth L.
Publication year - 2003
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.10109
Subject(s) - winter flounder , epidermis (zoology) , biology , metamorphosis , dermis , flounder , antifreeze protein , in situ hybridization , immunohistochemistry , anatomy , microbiology and biotechnology , messenger rna , biochemistry , fish <actinopterygii> , immunology , ecology , larva , fishery , gene
Two isotypes of Type I antifreeze protein (AFP), the liver‐type and the skin‐type, have been described from adult winter flounder ( Pseudopleuronectes americanus ). Although the liver‐type AFP has been well studied, the skin‐type has just begun to be characterized. It appears to have a wide tissue distribution, be expressed constitutively, and the absence of a signal sequence suggests it is active intracellularly. The current study was designed to examine the onset of skin‐type AFP expression during the thickening of the epidermis at metamorphosis from both the nucleic acid and protein levels. The epidermis appeared as a thin layer overlying a thickened dermis at metamorphosis and showed a gradual increase in thickness through the first fall and winter. The onset of skin‐type antifreeze expression occurred in conjunction with this epidermal thickening. In situ hybridization and immunohistochemistry showed a distribution of mRNA and skin‐type AFP specific for the epidermis and epidermal pavement cells. The AFP immunoproduct showed a distribution intimate with the pavement cell membrane and through the interstitial spaces. This distribution suggests that the AFP may be important in slowing ice crystal formation in these interstitial regions and thus reducing cellular damage due to osmotic imbalance. J. Morphol. 257:78–86, 2003. © 2003 Wiley‐Liss, Inc.