The FRT>HcRed1>FRT cassette has been excised, allowing the UASt regulatory sequences to drive expression of an inverted repeat of a 607bp apolpp fragment (corresponds to a 607bp sequence ending 47bp from the stop codon, which encodes part of the ApoLI protein produced by cleavage of the pro-Apolipophorin precursor).
Expression of RfabgdsRNA.ApoLI.Scer\UAS in the fat body under the control of Scer\GAL4Adh.PF (initiated by heat shock during the early larval stages) results in dramatic enlargement of the neutral fat droplets in the third instar larval posterior midgut.
Expression of RfabgdsRNA.ApoLI.Scer\UAS in the fat body under the control of Scer\GAL4Rfabg.PB (initiated by heat shock during the early larval stages) reduces the amount of all hemolymph lipid species in third instar larvae by over 10-fold.
In third instar larval guts expressing RfabgdsRNA.ApoLI.Scer\UAS in the fat body under the control of Scer\GAL4Adh.PF (initiated by heat shock during the early larval stages) the levels of medium-chain diacylglycerol (DAG) increase 5-8 fold with respect to polar lipids. Long chain DAG increases moderately, and contributes less to the total elevation in gut (DAG). Loss of Rfabg also leads to a strong increase in triacylglycerol (TAG) in the gut, with medium-chain TAG most strongly elevated. An increase in TAG and DAG is seen in both lipid-fed and lipid-starved animals.
Expression of RfabgdsRNA.ApoLI.Scer\UAS under the control of Scer\GAL4Adh.PF (initiated by heat shock during the early larval stages) has no effect on fat body triacylglycerol (TAG) levels. The level of fat body phosphatidylethanolamine (PE) 32:1 increases around 1.5 fold.
Expression of RfabgdsRNA.ApoLI.Scer\UAS under the control of Scer\GAL4Adh.PF (initiated by heat shock during the early larval stages) specifically depletes levels of medium chain diacylglycerol (DAG) in the third instar larval wing disc. Long-chain DAG levels are unaffected. Total triacylglycerol (TAG) levels are reduced by 60% and the size and number of neutral lipid droplets are strongly reduced. Both medium-chain and long-chain TAG levels are significantly affected. The levels of phospholipids, including phosphatidylethanolamine (PE) 32:1 and 34:1 , are also reduced.
Expression of RfabgdsRNA.ApoLI.Scer\UAS in the fat body under the control of Scer\GAL4Adh.PF (initiated by heat shock during the early larval stages) reduces the levels of medium-chain diacylglycerol (DAG) in the third instar larval brain, but has no effect on the long-chain species. Total brain triacylglycerol (TAG) is reduced by 60%. The levels of phospholipids, including phosphatidylethanolamine (PE) 32:1 and 34:1 , are unaffected.
Expression of RfabgdsRNA.ApoLI.Scer\UAS in the fat body under the control of Scer\GAL4Adh.PF (initiated by heat shock during the early larval stages) results in a 20% reduction in the levels of phosphatidylethanolamine (PE) 32:1 and 34:1 in the third instar larval wing disc and gut. No reduction in the levels of PC are seen.
