Transposons and non-coding regions drive the intrafamily differences of genome size in insects

Yuyang Cong; Xinhai Ye; Yang Mei; Kang He; Fei Li

doi:10.1016/j.isci.2022.104873

Transposons and non-coding regions drive the intrafamily differences of genome size in insects

iScience. 2022 Aug 4;25(9):104873. doi: 10.1016/j.isci.2022.104873. eCollection 2022 Sep 16.

Authors

Yuyang Cong¹, Xinhai Ye¹, Yang Mei¹, Kang He¹, Fei Li¹

Affiliation

¹ State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.

Abstract

Genome size (GS) can vary considerably between phylogenetically close species, but the landscape of GS changes in insects remain largely unclear. To better understand the specific evolutionary factors that determine GS in insects, we examined flow cytometry-based published GS data from 1,326 insect species, spanning 700 genera, 155 families, and 21 orders. Model fitting showed that GS generally followed an Ornstein-Uhlenbeck adaptive evolutionary model in Insecta overall. Ancestral reconstruction indicated a likely GS of 1,069 Mb, suggesting that most insect clades appeared to undergo massive genome expansions or contractions. Quantification of genomic components in 56 species from nine families in four insect orders revealed that the proliferation of transposable elements contributed to high variation in GS between close species, such as within Coleoptera. This study sheds lights on the pattern of GS variation in insects and provides a better understanding of insect GS evolution.

Keywords: Evolutionary biology; Genomics; Phylogenetics.