Chromatin accessibility profiling provides insights into larval cuticle color and adult longevity in butterflies

• DOI: 10.24272/j.issn.2095-8137.2021.117
• Publication Date: 2021-08-17T01:26:49Z
• Authors: Wen-Ting Wan; ; ; Zhi-Wei Dong; Yan-Dong Ren; Jie Yang; Xiang-Yu Pan; Jin-Wu He; Zhou Chang; Wei Liu; Gui-Chun Liu; Ruo-Ping Zhao; Ping Hu; Chu-Yang Mao; Jun Li; Wen Wang; Xue-Yan Li
• Keywords: 0301 basic medicine; 0303 health sciences; 03 medical and health sciences; Pigmentation; Larva; Animals; Gene Expression Regulation, Developmental; Pigments, Biological; Integumentary System; Transcriptome; Letter to the Editor; Butterflies; Chromatin

Butterflies are diverse in virtually all aspects of their ontogeny, including morphology, life history, and behavior. However, the developmental regulatory mechanisms underlying the important phenotypic traits of butterflies at different developmental stages remain unknown. Here, we investigated the developmental regulatory profiles of butterflies based on transposase accessible chromatin sequencing (ATAC-seq) at three developmental stages in two representative species ( Papilio xuthus and Kallima inachus). Results indicated that 15%-47% of open chromatin peaks appeared in associated genes located 3 kb upstream (i.e., promoter region) of their transcription start site (TSS). Comparative analysis of the different developmental stages indicated that chromatin accessibility is a dynamic process and associated genes with differentially accessible (DA) peaks show functions corresponding to their phenotypic traits. Interestingly, the black color pattern in P. xuthus 4th instar larvae may be attributed to promoter peak-related genes involved in the melanogenesis pathway. Furthermore, many longevity genes in 5th instar larvae and pupae showed open peaks 3 kb upstream of their TSS, which may contribute to the overwintering diapause observed in K. inachus adults. Combined with RNA-seq analysis, our data demonstrated that several genes enriched in the melanogenesis and longevity pathways also exhibit higher expression, confirming that the expression of genes may be closely related to their phenotypic traits. This study offers new insights into larval cuticle color and adult longevity in butterflies and provides a resource for investigating the developmental regulatory mechanisms underlying butterfly ontogeny.