PAN-GENOME ANALYSIS OF STRUCTURAL VARIATION AND ITS ROLE IN ADAPTIVE EVOLUTION ACROSS POPULATIONS

Abstract

Genomic diversity is largely caused by structural variations (SVs) and is an important factor in the evolution in individuals. Yet their role in adaptive evolution in a pan-genomic system is not clearly studied. The purpose of this study was to examine structural variations among populations and their distribution as well as functional effects and adaptive value in the context of pan-genome analysis. Entire genome data sets of various populations were used to build an extensive pan-genome after which more sophisticated bioinformatics methods were used to identify SVs (insertions, deletions, duplications, and inversions). A total of 12,846 structural variations were found, with about 38 being not present in all populations, and 62 shared among populations. Functional annotation found that about 27 percent of the SVs were linked to genes that carry out metabolic processes and mechanisms of responding to the environment. The result of population differentiation analysis showed that there was a great degree of genetic structuring (FST = 0.21, p < 0.05) which implied adaptive divergence. Also, some of the SVs were enriched at locations associated with ecological adaptation and stress tolerance. These results reveal the great importance of structural differences in genomic variation and adaptive evolution. The combination of pan-genome analysis and population genomics offers further understanding about evolutionary processes and also challenges the significance of trying to include SVs in subsequent evolutionary and functional genomics investigations.