Selective forces for the origin of the eukaryotic nucleus

Area of Science:

• Cell Biology
• Evolutionary Biology
• Genomics

Background:

• The origin of the eukaryotic cell nucleus and endoplasmic reticulum (ER) is controversial, with existing autogenous and endosymbiotic models lacking comprehensive explanations.
• Autogenous models suggest plasma membrane invagination but lack clear selective forces, while endosymbiotic models struggle with cell biology compatibility.

Purpose of the Study:

• To propose a reconciled evolutionary scenario for the eukaryotic nucleus and ER.
• To identify sequential selective forces driving their evolution.

Main Methods:

• Integration of existing knowledge on cell biology and evolutionary pathways.
• Development of a hypothetical evolutionary model based on endosymbiosis and autogenous processes.

Main Results:

• A proposed scenario involving the endosymbiosis of a methanogenic archaeon within a fermentative myxobacterium.
• Identification of two key selective forces: metabolic compartmentation and avoidance of aberrant protein synthesis.

Conclusions:

• The proposed model reconciles endosymbiotic and autogenous origins for the eukaryotic nucleus and ER.
• Metabolic compartmentation and prevention of aberrant protein synthesis were critical selective pressures in eukaryotic evolution.