Bijective codon transformations show genetic code symmetries centered on cytosine's coding properties.

Area of Science:

• Molecular Biology
• Genetics
• Evolutionary Biology

Background:

• RNA shares homology with DNA, necessitating systematic nucleotide exchanges.
• These exchanges, termed 'swinger' transformations, involve bijective mathematical operations.
• Understanding these transformations is key to deciphering genetic code origins.

Purpose of the Study:

• To analyze amino acid coding after swinger transformations.
• To define and characterize 'coding invariance' post-transformation.
• To explore the role of swinger transformations in genetic code genesis and evolution.

Main Methods:

• Comparison of amino acids coded by swinger-transformed codons versus untransformed codons.
• Clustering of swinger transformations based on coding invariance.
• Correlation analysis of coding invariance with biological factors like mitochondrial transcription and body temperature.

Main Results:

• Swinger transformations were grouped into four clusters based on coding invariance, primarily involving cytosine.
• Cytosine's central role in mutation highlights its influence on genetic code formation.
• Coding invariance showed correlations with mitochondrial swinger transcription and lepidosaurian body temperature.

Conclusions:

• Swinger transformations likely constrained the genesis of the genetic code.
• Temperature may influence swinger polymerization modes, affecting sequence length and mutation rates.
• Swinger transcription hypothetically enhanced the coding capacity of early RNA-based life systems.