TY - JOUR
T1 - Freeze-induced expression of a novel gene, fr47, in the liver of the freeze-tolerant wood frog, Rana sylvatica
AU - McNally, J. Dayre
AU - Sturgeon, Christopher M.
AU - Storey, Kenneth B.
N1 - Funding Information:
Thanks to J.M. Storey for critical commentary on the manuscript and to S. Eddy, D. McMullen, K. Larade and D. Hittel for help with animal experimentation and tissue collection. This work was supported by a postgraduate scholarship from the Natural Sciences and Engineering Research Council (NSERC) of Canada to J.D.M., a NSERC undergraduate student research award to C.M.S., and NSERC research grant OPG 6793 to K.B.S. K.B.S. holds the Canada Research Chair in Molecular Physiology (NSERC).
PY - 2003/1/27
Y1 - 2003/1/27
N2 - The ability to endure the freezing of body fluids is well developed as an adaptation for winter survival in several species of woodland frogs. Recently, the mechanisms supporting natural freeze tolerance have been shown to include the expression of novel genes. One such novel gene, fr47, codes for a 390-amino acid protein present in the livers of freeze-tolerant anurans (Rana sylvatica, Pseudacris crucifer, Hyla versicolor) but not in freeze-intolerant species (Rana pipiens, Scaphiopus couchii). Regulatory influences on gene and protein expression were investigated using R. sylvatica. Northern blot analysis showed that transcript levels were increased following 24 h of freezing (5.1-fold), 24 h of anoxia exposure (6.4-fold), or the loss of 20% of total body water (2.7-fold). Immunoblotting with anti-FR47 antibody indicated that protein levels increased during freezing and thawing, but decreased somewhat during anoxia or dehydration exposure, although rebounding during recovery. These results suggest that (i) FR47 function is important for freeze survival, and (ii) that control at the protein level may be exerted posttranscriptionally. Finally, assessment of putative signal transduction pathways regulating fr47 gene expression, via in vitro incubations of liver slices, indicated the involvement of a protein kinase C-mediated pathway.
AB - The ability to endure the freezing of body fluids is well developed as an adaptation for winter survival in several species of woodland frogs. Recently, the mechanisms supporting natural freeze tolerance have been shown to include the expression of novel genes. One such novel gene, fr47, codes for a 390-amino acid protein present in the livers of freeze-tolerant anurans (Rana sylvatica, Pseudacris crucifer, Hyla versicolor) but not in freeze-intolerant species (Rana pipiens, Scaphiopus couchii). Regulatory influences on gene and protein expression were investigated using R. sylvatica. Northern blot analysis showed that transcript levels were increased following 24 h of freezing (5.1-fold), 24 h of anoxia exposure (6.4-fold), or the loss of 20% of total body water (2.7-fold). Immunoblotting with anti-FR47 antibody indicated that protein levels increased during freezing and thawing, but decreased somewhat during anoxia or dehydration exposure, although rebounding during recovery. These results suggest that (i) FR47 function is important for freeze survival, and (ii) that control at the protein level may be exerted posttranscriptionally. Finally, assessment of putative signal transduction pathways regulating fr47 gene expression, via in vitro incubations of liver slices, indicated the involvement of a protein kinase C-mediated pathway.
KW - Cryobiology
KW - Freeze tolerance
KW - Gene expression
KW - Liver
KW - Protein expression
KW - Second messenger
UR - http://www.scopus.com/inward/record.url?scp=0037467669&partnerID=8YFLogxK
U2 - 10.1016/S0167-4781(02)00603-6
DO - 10.1016/S0167-4781(02)00603-6
M3 - Article
C2 - 12531477
AN - SCOPUS:0037467669
SN - 0167-4781
VL - 1625
SP - 183
EP - 191
JO - Biochimica et Biophysica Acta - Gene Structure and Expression
JF - Biochimica et Biophysica Acta - Gene Structure and Expression
IS - 2
ER -