mTAIL-seq reveals dynamic poly(A) tail regulation in oocyte-to-embryo development

Area of Science:

• Molecular Biology
• Developmental Biology
• Genomics

Background:

• Eukaryotic messenger RNA (mRNA) stability and translation are regulated by tailing processes.
• Previous TAIL-seq lacked sensitivity for analyzing small biological samples.
• Investigating poly(A) tail dynamics is crucial for understanding gene expression control.

Purpose of the Study:

• To develop a highly sensitive method for analyzing mRNA poly(A) tails at a genomic scale.
• To investigate the regulation and function of poly(A) tails in Drosophila oocytes and embryos.
• To correlate poly(A) tail length with translational efficiency during early development.

Main Methods:

• Developed mRNA TAIL-seq (mTAIL-seq), a high-depth sequencing technique for mRNA poly(A) tails.
• Applied mTAIL-seq to analyze poly(A) tail dynamics in Drosophila oocytes and embryos.
• Integrated mTAIL-seq data with ribosome profiling data.

Main Results:

• mTAIL-seq offers a ~1000-fold increase in sequencing depth compared to the previous version.
• Maternal mRNA polyadenylation primarily occurs during late oogenesis, with subsequent modifications after egg activation.
• Wispy, a noncanonical poly(A) polymerase, is responsible for adenylating most maternal mRNAs.
• A strong correlation exists between poly(A) tail length and translational efficiency during egg activation.
• Poly(A) tail regulation in oocytes shapes the embryonic translatome, guiding development.

Conclusions:

• mTAIL-seq is a sensitive, cost-effective, and robust tool for studying mRNA tailing.
• Poly(A) tail regulation in oocytes is a key determinant of developmental trajectories.
• This method advances the understanding of mRNA processing in various biological systems.