A Lipidome Map of the Silkworm Bombyx mori: Influences of Viral Infection

Lipids have been recently proposed
as key molecules for virus entry
and egress, and lipid biosynthesis and signaling were reported necessary
for some viruses during replication and infection. The silkworm Bombyx mori is an important economic insect and a
model organism, but its lipid profiles have not been systematically
investigated. Most silkworm strains are susceptible to the B. mori nuclear polyhedrovirus (BmNPV), a baculovirus
that causes serious loss to the sericulture industry. Previously,
our lab has screened a natural mutant of B. mori that is highly resistant to BmNPV. In this study, a comprehensive
lipidomic analysis by ultrahigh pressure liquid chromatography-mass
spectrometry (UPLC-MS) was carried out on the BmNPV-susceptible strain
306 and resistant strain NB (data deposited in MetaboLight MTBLS2142).
Comparisons of the lipid profiles between the two strains reveal that
phosphosphingolipids, diacylglycerolipids, ceramides, and quinones
were present at notably higher levels in the susceptible strain, while
lysophosphocholines were found at a higher level in the resistant
strain. BmNPV administration changed the lipid profiles in both strains,
revealing key lipids involved in virus infection and immune response.
Some key enzymes in the lipid biosynthesis pathway were analyzed for
their activities in the two silkworm strains and their virus-administered
counterparts, underlining the relation among lipid biosynthesis, viral
resistance, and immune response in the host.