Figure S1. Genome-wide chromosomal heatmap of Yoshiicerus persimilis.;Figure S2. GO (a, b) and KEGG enrichment (c, d) for genes located in duplicated regions within ElChr in Y. persimilis and T. qinae, respectively. from Genomic insights into the chromosomal elongation in a family of Collembola

Collembola is a highly diverse and abundant group of soil arthropods with chromosome numbers ranging from 5 to 11. Previous karyotype studies indicated that the Tomoceridae family possesses an exceptionally long chromosome. To better understand chromosome size evolution in Collembola, we obtained a chromosome-level genome of Yoshiicerus persimilis with a size of 334.44 Mb and BUSCO completeness of 97.0% (n = 1013). Both genomes of Y. persimilis and Tomocerus qinae (recently published) have an exceptionally large chromosome (ElChr greater than 100 Mb), accounting for nearly one-third of the genome. Comparative genomic analyses suggest that chromosomal elongation occurred independently in two species approximately 10 million years ago, rather than in the ancestor of the Tomoceridae family. The ElChr elongation was caused by large tandem and segmental duplications, as well as transposon proliferation, with genes in these regions experiencing weaker purifying selection (higher dN/dS) than conserved regions. Moreover, inter-genomic synteny analyses indicated that chromosomal fission/fusion events played a crucial role in the evolution of chromosome numbers (ranging from 5 to 7) within Entomobryomorpha. This study provides a valuable resource for investigating the chromosome evolution of Collembola

Table S1:;Table S2. from Genomic insights into the chromosomal elongation in a family of Collembola

Comparison of the largest chromosome of the Yoshiicerus persimilis genome with that of other published collembolan chromosome-level genomes.;Statistics of the sequencing data used for genome assembly