The Wap65 gene expression of goldfish (Carassius auratus) in association with warm water temperature as well as bacterial lipopolysaccharide (LPS)

The expression of the Wap65 mRNA was compared between hepatopancreas, intestine, ovary, heart, gill, eye, skin, hemocytes, muscle, and brain from 30 degrees C-acclimated goldfish (Carassius auratus) by reverse transcription PCR, demonstrating the highest levels of expression of the gene in the hepatopancreas. Other tissues expressing the gene were ovary, gill, eye, and muscle, whereas Wap65 mRNA could not be detected in intestine, heart, skin, and brain. In Northern blot analysis, levels of Wap65 mRNA in the hepatopancreas increased after raising water temperature from 10 to 30 degrees C. The transcript levels reached a maximum of 40-fold on day 3 following temperature shift. On day 21 after raising water temperature, levels were 10-fold compared with those of the 10 degrees C-acclimated fish. Subsequently, in order to elucidate the transcriptional mechanisms of Wap65, a part of the Wap65 gene was cloned from a genomic library. The 5'-flanking region and introns of this gene contained enhancer motifs including cytokine responsive elements previously identified in mammals. The suggesting that some of these motifs are involved in the transcriptional regulation of Wap65, was tested by administering of lipopolysaccharide (LPS) to the 10 degrees C-acclimated goldfish. This resulted in the accumulation of Wap65 mRNA in the hepatopancreas, suggesting the involvement of immune associated factors in the regulation of transcription of Wap65.