GENE EXPRESSION AND LIPID PROFILE OF RED DRUM, Sciaenops ocellatus, EGGS THAT DEMONSTRATE METABOLIC PROGRAMMING

Previous work in our lab has shown that when the diet of red drum (Sciaenops ocellatus) broodstock is manipulated to produce varying levels of docosahexaenoic acid (DHA) in the egg, resulting larvae demonstrate altered abilities to acquire and/or retain DHA in body tissues despite being provided high levels in their diet.  This difference is exacerbated when egg DHA levels are < 30 mg/g as dry weight and reach a steady state at approximately 40 mg/g DHA.  This pattern is similar to a condition seen in terrestrial vertebrates and referred to in humans as the Metabolic Syndrome.  

In order to better understand the mechanisms behind this difference, we reared larvae from two different egg sources (Texas Parks and Wildlife Department Marine Development Center and the University of Texas Fisheries and Mariculture Lab) and egg DHA concentrations ranging from 25 to 55 mg/g DHA.  DHA concentration gradients were obtained by changing the diet of spawning fish and collecting eggs over a single spawning season to obtain samples as DHA concentrations were altered.  Collected eggs were then hatched and reared under common garden conditions with periodic sampling of resulting larvae through day 21 post-hatch.  Eggs were analyzed via tag-based RNA-Seq (TagSeq) and by Gas Chromatography - Mass Spectrometry analysis to determine gene expression and lipid profile, respectively.