Data for: Butterfly eyespots exhibit unique patterns of open chromatin

How the precise spatial regulation of genes is correlated with spatial variation in chromatin accessibilities is not yet clear. Previous studies that analysed chromatin from homogenates of whole-body parts of insects found little variation in chromatin accessibility across those parts, but single-cell studies of Drosophila brains showed extensive spatial variation in chromatin accessibility across that organ. In this work we studied the chromatin accessibility of butterfly wing tissue fated to differentiate distinct colors and patterns in pupal wings of Bicyclus anynana. We observed that three dissected wing regions showed unique chromatin accessibilities. Open chromatin regions specific to eyespot color patterns were highly enriched for binding motifs recognized by Suppressor of Hairless (Su(H)), Krüppel (Kr), Buttonhead (Btd) and Nubbin (Nub) transcription factors. Genes in the vicinity of the eyespot-specific open chromatin regions included those involved in wound healing and SMAD signal transduction pathways, previously proposed to be involved in eyespot development. We conclude that eyespot and non-eyespot bits of tissue taken from the same wing have distinct patterns of chromatin accessibility, possibly driven by the eyespot-restricted expression of potential pioneer factors, such as Kr.

Methods
We dissected small eyespot and adjacent control tissues from 3hr pupae and performed ATAC-Seq to identify the chromatin accessibility differences between different sections of the wings.

基因的精准空间调控与染色质可及性的空间变异之间存在何种关联，目前尚未明确。此前针对昆虫全身组织匀浆的染色质分析研究，未观测到这些组织间存在显著的染色质可及性差异，但针对果蝇（Drosophila）大脑的单细胞研究则显示该器官内染色质可及性存在广泛的空间变异。
本研究以斑蝶Bicyclus anynana的蛹翅为研究对象，针对其体内注定分化为不同颜色与图案的翅组织开展染色质可及性分析。我们发现三个经解剖分离的翅区域具有独特的染色质可及性特征。眼斑颜色图案特异性的开放染色质区域，高度富集了抑毛素（Suppressor of Hairless, Su(H)）、Krüppel（Kr）、Buttonhead（Btd）以及Nubbin（Nub）等转录因子的结合基序。眼斑特异性开放染色质区域邻近的基因，涵盖了此前被认为参与眼斑发育的、与伤口愈合及SMAD信号转导通路相关的基因。综上，从同一翅组织中分离得到的眼斑与非眼斑区域，其染色质可及性模式存在显著差异，这一差异可能由Krüppel（Kr）等潜在先锋因子在眼斑区域的特异性表达所驱动。
方法
我们从3小时龄的蛹体中解剖分离小型眼斑组织及其邻近的对照组织，并通过ATAC测序（ATAC-Seq）鉴定不同翅区域间的染色质可及性差异。