NeGA : Influence of effective population size on animal genome architecture

[2020-2024]

Eukaryotic organisms exhibit strikingly complex gene and genome architectures whose origin remains largely debated. In 2003, Michael Lynch proposed that this complexity emerged thanks to non-adaptive forces. Under this hypothesis, many genomic traits would be controlled by the balance between the emergence of slightly deleterious variants and their fixation rate, which ultimately depends on the effective population size (Ne). Although appealing because it is based on universal principles of population genetics, Lynch’s theory has rarely been tested empirically. Here, we will compare the genome architecture of closely related species with contrasted Ne in five different groups of animals. We will first evaluate the influence of Ne on the evolution of genome size and on the dynamics of transposable elements. Then, we will test if Ne has an influence on the gene structure (number and size of introns) and transcription complexity (number and frequency of alternative transcripts).