Genome-wide analysis of mRNA regionalization in a giant single cell

Area of Science:

• Cell Biology
• Developmental Biology
• Molecular Biology

Background:

• Cellular structure formation mechanisms are not fully understood.
• The giant ciliate Stentor coeruleus offers a model for studying single-cell structure formation due to its size and regenerative capabilities.
• Regionalized mRNA is known to mark position in embryonic development.

Purpose of the Study:

• To investigate whether regionalized mRNAs mark positional information along the anterior-posterior axis in Stentor.
• To identify specific mRNAs enriched in anterior or posterior cell halves.
• To determine the role of microtubules in mRNA localization and cell regeneration.

Main Methods:

• Physical bisection of Stentor cells followed by bulk RNA sequencing.
• RNA interference (RNAi)-mediated knockdown of specific genes (MYB, β-tubulin, dynein).
• Half-cell RNA sequencing in control and experimentally manipulated cells.

Main Results:

• Identified sets of mRNA enriched in either the anterior or posterior halves of Stentor cells.
• Knockdown of posterior-enriched MYB gene transcripts impaired posterior regeneration.
• Disruption of microtubule cytoskeleton (via RNAi of β-tubulin or dynein) altered mRNA regionalization, with some anterior-enriched messages becoming posterior-enriched and vice versa.

Conclusions:

• mRNA is regionalized within the single giant cell Stentor.
• Microtubules may function as tracks for mRNA movement, influencing positional information.
• This localization is crucial for cell regeneration and the formation of cellular structure.