Fol. Biol. 2009, 55, 98-106
Gene Expression Responses in Larvae of the Fleshfly Sarcophaga bullata after Immune Stimulation
Insect larvae develop in decaying organic matter and their defence against various microorganisms must therefore be highly efficient. In the present study, we explored the transcriptional kinetics and induction levels of eight genes in Sarcophaga bullata larvae after infection or aseptic injury. Using real-time PCR, we studied the time-dependent immune response of larvae of the fleshfly S. bullata. We compared the mRNA levels of eight selected genes in induced and non-induced larvae. The third-instar larvae of S. bullata were induced by injecting a bacterial suspension of Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa, or by simple aseptic injury with an entomological pin. We used intact larvae as a control for basal mRNA expression. Total RNA was isolated from the whole body, fat body and haemocytes. We determined the mRNA levels of genes encoding sapecin, transferrin, prophenoloxidase 1 and 2, storage-binding protein, cathe psin L, sarcocystatin, and 26/29 kDa protease. We found that there was massive up-regulation of genes encoding the fleshfly peptide sapecin, as well as the protein transferrin. We also detected down-regulation of, or no change in, the expression of genes that encode prophenoloxidase 1 and 2, storage-binding protein, cathepsin L, sarcocystatin, and 26/29 kDa protease.
Keywords
gene expression, immune stimulation, larvae, fleshfly, Sarcophaga bullata, sapecin, transferrin, bacteria, injury.
Funding
The project was supported by Grant 203/05/0832 (to J.J.) from the Grant Agency of the Czech Republic, by the Chemical Genetics Consortium No. LC060777 of the Ministry of Education, Youth and Sports of the Czech Republic (to J.J.) and by Research Project Z4 055 0506 of the Academy of Sciences of the Czech Republic. R.Š. and M.K. were supported by grant B500520601 and project AV0Z50520701 awarded by the Grant Agency of the Academy of Sciences of the Czech Republic.
References
Copyright
This is an open-access article distributed under the terms of the Creative Commons Attribution License.
