larvi 2013

ghent university, belgium, 2-5 september 2013

6th fish & shellfish larviculture symposium

Lipid digestion in first feeding larvae -visualization in vivo

Øystein Saele

Lipid digestion in first feeding larvae,an in vivo study

Øystein Sæle, Kari Elin Rød & Steven Farber

How to study lipid digestion in a 4 mm fish larvae?

Homogenate of whole animal• Enzyme activity• Protein (western blot/ELISA)• Gene expression (qPCR)

Liver Brain Kidney Gill MuscleTissue

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

Act

ivity

n.d.

Sæle et al., 2011

Absorbed

Gut Retained

Evacuated

Catabolised (CO2)

4.5 mm SL

Ingested

Radiolabeled lipids

18:1 – C11TopFluo – C11TopFluo

Fluorescent lipids

0.06% 99.94%

Emulsions

Lipid digestion

BAL

HPLC fluorescent detector

Rinse Extract

Digested and re-synthesized

Undigested

Ingested

Absorbed

Gut

Retained

EvacuatedCatabolised (CO2)

Fluorecent lipids

Visualization

Orlistat TG

TG

Orlistat TG+PC

TG+PC

Quantification

Phospholipid digestion

Feeding trials

TG

PC

TG

PCTGPCTGPC

a a

ba

a a

b

a

Atlantic cod larvae

a

b c

d

TG

PC

TG

PCTGPCTGPC

Atlantic cod larvae

Chemicals that affect lipid digestionGenes that affect lipid digestionconclusionsWe have developed a tool for screening:

Conclusions

Chemicals that affect lipiddigestion

Genes that affect lipid digestion

How nutrient composition affectlipid metabolism

Thank youThis work has been financed by the Norwegian Research Council project: CODE.

We would like to thank Avanti Polar Lipids, Inc (USA) for donating the TopFluor lipids