Identifying gene expression from single cells to single genes.

Area of Science:

• Developmental Biology
• Genomics
• Molecular Biology

Background:

• Gene regulatory networks (GRNs) orchestrate complex cellular functions through transcription factors.
• Technological advancements have improved the ability to study GRN mechanisms and connections.
• Echinoderms offer a valuable model system for studying fundamental biological processes.

Purpose of the Study:

• To present a logical experimental protocol for interrogating transcriptional mechanisms in echinoderms.
• To highlight the utility of single-cell mRNA sequencing, nascent RNA detection, and chromatin immunoprecipitation (ChIP).
• To provide a framework for applying these technologies to echinoderm embryos, larvae, and adult tissues.

Main Methods:

• Single-cell mRNA sequencing (e.g., drop-seq) to identify cell-specific gene expression.
• Nascent RNA detection using Click-iT chemistry to determine RNA transcription timing.
• Chromatin immunoprecipitation (ChIP) to investigate direct interactions between transcription factors and gene promoters.

Main Results:

• Differential gene expression studies (DE-seq) combined with single-cell sequencing can define cell-specific gene roles.
• Nascent RNA analysis provides temporal information on gene transcription.
• ChIP assays reveal direct regulatory interactions critical for gene expression control.

Conclusions:

• A combined approach using single-cell sequencing, nascent RNA detection, and ChIP offers a powerful strategy for dissecting GRNs in echinoderms.
• These methods, adapted for echinoderms, advance the understanding of transcriptional regulation in development and cellular processes.
• The presented workflow is broadly applicable to diverse organisms and cell types, with specific considerations for echinoderm models.