Ontogeny of alpha-amylase gene expression in sea bass larvae (Lates calcarifer)

The enzymatic activities of alpha -amylase and its corresponding messenger RNA levels in developing sea bass (Lates calcarifer) larvae were studied fr om hatching until 27 days post hatching (dph). An increasing activity of am ylase enzyme was measured until 5 dph, and the activity gradually decreased thereafter and reached a constant level by 12 dph. To achieve a better und erstanding of the molecular mechanisms underlying amylase expression, we ha ve cloned and sequenced a 318-bp fragment of alpha -amylase complementary D NA. Based on this sequence, a real-time reverse transcriptase polymerase ch ain reaction technique to monitor the changes in the mRNA levels in the lar vae was developed. A correlation between enzymatic activity and mRNA level of alpha -amylase could be demonstrated during the early development of sea bass larvae. This suggests that the changes in alpha -amylase are controll ed at least at the transcriptional level during early larval development of sea bass.