Abstract
Advances in sequencing technologies have enabled the determination of genome sequences of multiple lines within a single species. Comparative analysis of multiple genome sequences reveals all genes present within a species, providing insight into the genetic mechanisms that lead to the establishment of species. Highly accurate pan-genome analysis requires telomere-to-telomere gapless genome assembly, providing an ultimate genome sequence that covers all chromosomal regions without any undetermined nucleotide sequences. This review describes the genome sequencing technologies and sophisticated bioinformatics required for telomere-to-telomere gapless genome assembly, as well as a genetic mapping that can evaluate the accuracy of telomere-to-telomere genome assembly. Pan-genome analyses may contribute to the understanding of genetic mechanisms not only within a single species but also across species.