Ontogenetic studies of the digestive capability of haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua) larvae

In chapter 2 I report on the digestive enzymes present in larvae of haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua) through development. I used biochemical techniques to determine the activity of general proteases (GP), trypsin-like enzymes (TLE), pepsin-like enzymes (PLE), general lipase (GL), bile salt-activated lipase (BAL), alkaline phosphatase (AP) and α-amylase in larvae of both species. In chapter 3 I report a partial sequence of 1250 bp and characterization of a BAL cDNA from haddock. The sequence contains the bile salt-binding site characteristic of all BAL enzymes at positions 139–152, and the lipid-binding site exclusive of fish BAL's starting at position 450. The active site serine motif is present starting at position 214, a catalytic triad formed by the residues S217, D344 and H463, and an N-glycosylation site at position 210. The relative levels of BAL gene expression were determined in haddock larvae during ontogeny using the housekeeping gene glyceraldehyde 3-phosphate dehydrogenase. (Abstract shortened by UMI.)...