INVESTIGADORES
CUNNINGHAM Monica Liliana
congresos y reuniones científicas
Título:
First insight into the lipid uptake, storage and mobilization in arachnids. Role of midgut diverticula and lipoproteins
Autor/es:
LAINO ALDANA; GARCIA FERNANDO; HERAS HORACIO; CUNNINGHAM MONICA
Lugar:
Oviedo
Reunión:
Congreso; XXXII Congreso de la Sociedad Española de Bioquímica y Biología Molecular.; 2009
Resumen:
The importance of midgut diverticula (M-diverticula) and hemolymph lipoproteins
in the lipid homeostasis of Polybetes phythagoricus was
studied.Radioactivity distribution in tissues and hemolymph was analyzed
either after feeding or injecting [1-C 14 ]-palmitate. In both
experiments, radioactivity was mostly taken up by M-diverticula that synthesized
diacylglycerols, triacylglycerols and phospholipids in a ratio close to its
lipid class composition. M-diverticula total lipids represent 8.08% (by wt),
mostly triacylglycerols (74%) and phosphatidylcholine (13%). Major fatty acids
were (in decreasing order of abundance) 18:1n-9, 18:2n-6, 16:0, 16:1n-7, 18:0,
18:3n-3. Spider hemocyanin-containing lipoprotein (VHDL) transported 83 % of
the circulating label at short incubation times. After 24h, VHDL and HDL-1
(comparable to insect lipophorin), but not HDL-2 were found to be involved in
lipid uptake and release from M-diverticula. Lipoprotein labelled lipid class
changed with time, phospholipids becoming the main circulating lipid after
24h. These results indicate that arachnid M-diverticula play a central role
in lipid synthesis, storage and movilization, analogous to insect fat body or
crustacean midgut gland. The relative contribution of HDL-1 and VHDL to lipid
dynamics indicated that, unlike insects, spider VHDL contributes significantly
to the lipid exchange between M-diverticula and hemolymph.