Background: Strict regulation of caste differentiation, at the molecular level, is thought to be important to maintain social structure in insect societies. Previously, a number of extrinsic and intrinsic factors have been shown to influence caste composition in termite colonies. One important factor is the influence of nestmates; in particular, soldier termites are known to inhibit hormone-dependent worker-to-soldier differentiation. However, soldier influences on nestmates at the molecular level are virtually unknown. Here, to test the hypothesis that soldiers can influence nestmate gene expression, we investigated the impact of four treatments on whole-body gene expression in totipotent Reticulitermes flavipes workers: (i) juvenile hormone III (JHIII; a morphogenetic hormone), (ii) soldier head extracts (SHE), (iii) JHIII+SHE, and (iv) live soldiers.Results: Using quantitative-real-time PCR we determined the expression patterns of 49 previously identified candidate genes in response to the four treatments at assay days 1, 5, and 10. Thirty-eight total genes from three categories (chemical production/degradation, hemolymph protein, and developmental) showed significant differential expression among treatments. Most importantly, SHE and live soldier treatments had a significant impact on a number of genes from families known to play roles in insect development, supporting previous findings and hypotheses that soldiers regulate nestmate caste differentiation via terpene primer pheromones contained in their heads.Conclusions: This research provides new insights into the impacts that socio-environmental factors (JH, soldiers, primer pheromones) can have on termite gene expression and caste differentiation, and reveals a number of socially-relevant genes for investigation in subsequent caste differentiation research.
|Journal||BMC Molecular Biology|
|State||Published - Apr 23 2010|
Bibliographical noteFunding Information:
We thank Aurélien Tartar for assistance with gut gene bioinformatics, Daniel Hahn for valuable discussions on expression analysis, and Alan Lax and Dunhua Zhang for critical reading of manuscript drafts. This work was supported by CSREES-USDA-NRI grant No. 2007-35607-17777 to MES and XZ, by The Consortium for Plant Biotechnology Research, Inc. and DOE Prime Agreement No. DE-FG36-02GO12026 to MES, and a University of Florida IFAS Innovation Grant to MES.
ASJC Scopus subject areas
- Molecular Biology