Maternal Ribosomes Are Sufficient for Tissue Diversification during Embryonic Development in C. elegans

Area of Science:

• Molecular Biology
• Developmental Biology
• Genetics

Background:

• Ribosomes are essential for protein synthesis and cellular function.
• Ribosome biogenesis is a complex process involving ribosomal proteins (RPs) and ribosomal RNA (rRNA).
• The requirement for newly synthesized ribosomes during development is not fully understood.

Purpose of the Study:

• To investigate the necessity of newly composed ribosomes for developmental progression in Caenorhabditis elegans.
• To determine the role of ribosomal proteins (RPs) and ribosomal RNA (rRNA) in C. elegans embryogenesis and larval development.

Main Methods:

• Utilized Caenorhabditis elegans as a model organism.
• Generated null homozygotes lacking specific ribosomal proteins (RPs) and deleted the ribosomal RNA (rRNA) locus.
• Performed embryogenesis and larval development assays.
• Conducted mosaic analyses to assess cell-specific requirements.
• Evaluated postembryonic neuronal plasticity.

Main Results:

• Null homozygotes lacking any of five different RPs or with complete rRNA deletion completed embryogenesis, producing functional first-stage larvae.
• These larvae relied solely on maternal ribosomal components.
• Animals lacking new ribosomal components arrested before the first larval stage and showed impaired neuronal plasticity.
• Mosaic analyses indicated that ribosomal insufficiency in a subset of cells triggered organism-wide growth arrest.

Conclusions:

• Newly synthesized ribosomes are dispensable for C. elegans embryogenesis.
• Ribosomal protein and RNA synthesis are crucial for postembryonic development and neuronal plasticity.
• A global regulatory mechanism exists where partial ribosomal insufficiency can induce organism-wide growth arrest.