Quantitative chromatin immunoprecipitation (Q-ChIP) applied to Schistosoma mansoni

The life-cycle of the platyhelminth parasite Schistosoma mansoni is characterized by marked morphological changes between the various stages that are the result of a complex developmental program. In order to study the role of epigenetic mechanisms in regulating this program, and more particularly the role of changes in histone modifications in the control of the transcription of key genes, we have adapted the technique of quantitative chromatin immunoprecipitation (Q-ChIP) to larval stages and adult worms. We have used the classical method involving formaldehyde-induced cross-linking of DNA-associated proteins, followed by ultrasonication to fragment the DNA before immunoprecipitation and have established a protocol for use with schistosomes. We show, using antibodies directed against acetylated histone H4, that the technique is applicable to the parasite and allows the quantification and comparison of the levels of modified histone at gene promoters at different life-cycle stages. (C) 2009 Elsevier B.V. All rights reserved.