Biased intrachromosomal gene conversion in a chromosome lineage

Area of Science:

• Population genetics
• Molecular evolution
• Genomics

Background:

• Tandemly repeated genes evolve under various forces, including gene conversion.
• Intrachromosomal gene conversion plays a role in maintaining sequence homogeneity within gene families.

Purpose of the Study:

• To further analyze and extend a model for tandemly repeated gene evolution under intrachromosomal gene conversion.
• To derive approximations for key evolutionary parameters and investigate sequence homogeneity dynamics.

Main Methods:

• Analysis of an existing model for gene family evolution.
• Derivation of direct and diffusion approximations for fixation probabilities and fixation times.
• Investigation of the distribution of variant repeats under gene conversion and mutation.

Main Results:

• Exact and approximate expressions for stationary distributions were derived.
• Conversional bias was shown to significantly increase sequence homogeneity at equilibrium.
• The diffusion processes are applicable to selection and mutation in finite populations, yielding new results.

Conclusions:

• Gene conversion bias is a critical factor in maintaining sequence homogeneity in tandemly repeated genes.
• The developed diffusion approximations provide valuable tools for studying genetic variation.
• The study contributes to understanding fundamental evolutionary processes in genetics.