A limiting rule for the variability of coding sequence length in microbial genomes

TL;DR

This study identifies a limiting rule governing the relationship between the mean length and variability of coding sequences in microbial genomes, revealing bounds and a potential primordial origin point.

Contribution

It introduces a novel angular area model describing the variability limits of microbial genomes based on mean coding sequence length.

Findings

Variability increases with mean length in microbial genomes

Upper and lower bounds constrain variability for given mean lengths

Extrapolation suggests a primordial cell origin point

Abstract

The mean length and the variability of coding sequences for 48 genomes of bacteria and archaea were analyzed. It was found that the plotted data can be described by an angular area. This suggests the followings: a) The variability of a genome increases as the mean length increases; b) There is an upper and a lower limit for variability for a given mean length; c) Extrapolation of the upper and lower limits to lower mean values converges to a single point which might be assimilated to a primordial cell. The whole picture is reminding of a process which starts from a single cell and evolves into more and more species which, in turn, show more and more variability.