Developmental effector gene regulation: Multiplexed strategies for functional analysis.

Area of Science:

• Developmental Biology
• Genomics
• Molecular Biology

Background:

• Understanding genome complexity in development requires analyzing cis-regulatory elements.
• New high-throughput methods enable precise perturbation and readout of gene regulation.
• Sea urchin embryos provide a tractable model for studying gene regulatory networks (GRNs).

Purpose of the Study:

• To investigate the necessity and sufficiency of cis-regulatory modules (CRMs) in their native genomic context.
• To develop and apply high-throughput, multiplexed methods for cis-regulatory analysis.
• To characterize the regulatory inputs controlling skeletogenic effector genes in sea urchins.

Main Methods:

• Utilized recombineered bacterial artificial chromosomes (BACs) for cis-regulatory analyses.
• Employed Nanostring experiments with barcoded vectors for high-throughput screening of CRMs.
• Performed computational analysis of DNA sequences to identify functional target sites.
• Used deletion and site-mutation analyses in multiplex formats to test CRM necessity and sufficiency.

Main Results:

• Identified positively active CRMs for previously unstudied sea urchin skeletogenic effector genes.
• Computational analysis pinpointed functional target site clusters within CRMs.
• Deletion and mutation studies confirmed the necessity and sufficiency of identified regulatory elements.
• Demonstrated that each effector gene utilizes a small subset of inputs from the skeletogenic GRN.

Conclusions:

• Sea urchin effector genes are controlled by a limited set of specific regulatory inputs.
• These inputs modulate expression levels or are critical for gene activation.
• The study provides insights into the wiring of effector gene sub-circuits within the broader GRN architecture.