Isolated C. elegans germ nuclei exhibit distinct genomic profiles of histone modification and gene expression

The wide variety of specialized permissive and repressive mechanisms by which germ cells regulate developmental gene expression are not well understood genome-wide. Isolation of germ cells with high integrity and purity from living animals is necessary to address these open questions, but no straightforward methods are currently available.

Here we present an experimental paradigm that permits the isolation of nuclei from C. elegans germ cells at quantities sufficient for genomic analyses. We demonstrate that these nuclei represent a very pure population and are suitable for both transcriptome analysis (RNA-seq) and chromatin immunoprecipitation (ChIP-seq) of histone modifications. From these data, we find unexpected germline- and soma-specific patterns of gene regulation.

This new capacity removes a major barrier in the field to dissect gene expression mechanisms in the germ line of C. elegans. Consequent discoveries using this technology will be relevant to conserved regulatory mechanisms across species.