Gene family expansion analysis and identification of the histone family in Spodoptera frugiperda

Spodoptera frugiperda, a major invasive pest, causes severe damage to various economically important crops. Previous comparative genomics studies have revealed a close association between the invasiveness of S. frugiperda and its genome. In recent years, a vast amount of genome from lepidopteran species has become available, offering an opportunity for a more detailed and comprehensive understanding of the biological characteristics of S. frugiperda. In this study, we conducted a comprehensive comparative genomics analysis of S. frugiperda using genome from 46 lepidopteran species. We found the highest number of gene family expansion events in S. frugiperda, indicating that gene family expansion is a crucial mechanism in its adaptive evolution. The expanded gene families are enriched in various biological processes, including nutrient metabolism, development, stress response, reproduction, and immune processes, suggesting that the expansion of these gene families likely contributes to the strong environmental adaptability of S. frugiperda. Furthermore, we identified the expansion of histone gene families in S. frugiperda which resulted from chromosome segmental duplications after the divergence from closely related species. Expression analysis of histone genes indicated that certain members might exert an influence on the growth and reproduction processes of S. frugiperda. Overall, our study deepens our understanding of the biological characteristics of S. frugiperda, providing a theoretical basis for the comprehensive management and sustained control of S. frugiperda and other lepidopteran pests in the future.