The aim of our study was to determine the extent to
which, if any, marine zooplankton are able to undertake
this conversion. Linolenic acid is a precursor to the
longer chain n-3 PUFA, and a commercially available,
deuterated (D5) form of this fatty acid was used as a
tracer to quantify elongation and desaturation activity
in four different species of zooplankton. This tracer has
the label on carbons 17 and 18 at the methyl end of the
acyl chain and thus has the advantage over a label on
C1 at the carboxyl end, which can be removed by
b-oxidation and reincorporated by elongation.
Liposomes were used as a tracer delivery system and
gas chromatography-mass spectrometry (GC-MS) used
to detect the products of fatty acid elongation and desaturation.
Liposomes have previously been used to introduce
compounds of interest to a variety of aquatic
organisms