A single master regulatory gene optix underlies both color and iridescence in butterflies

It is debated to what extent individual regulatory genes might underlie non-gradualistic evolution of complex morphological traits. We have shown that a single regulatory gene, optix, is required for development of all color and iridescence in nymphalid butterfly wings by CRISPR/Cas9 genome editing. To investigate how wing features are controlled by optix, we used mRNA-seq to compare transcript abundance in wild type and optix knockout wings of V. cardui and J. coenia. We generated an average of 269 million reads 36 bp paired-end Nexseq 500 reads from 16 libraries and identified numerous candidate genes including known genes involved in the insect melanin and ommochrome biosynthetic pathways and suspected components potential involved in scale structure. Overall design: Butterfly forewings and hindwings were sampled separately at a late stage of pupal development when ommochrome and melanin pigments are both becoming visible, with two biological replicates each of both wild type and knockout phenotypes, using Illumina Nextseq 500 for 36 bp paired end sequencing.

单个调控基因在多大程度上可作为复杂形态性状非渐进式演化的基础，这一问题尚存争议。我们通过CRISPR/Cas9基因组编辑（CRISPR/Cas9 genome editing）技术证实，单个调控基因optix对于蛱蝶科蝴蝶翅膀的全部色彩与虹彩发育均为必需。为探究optix对翅膀性状的调控机制，我们采用mRNA测序（mRNA-seq）技术，对比分析了赤蛱蝶（Vanessa cardui）与孔雀蛱蝶（Junonia coenia）的野生型（wild type）和optix敲除（knockout）翅膀的转录本丰度。我们从16个文库中平均获得2.69亿条36 bp双端（paired-end）测序读段，依托Illumina Nexseq 500测序平台完成测序，并筛选出大量候选基因，其中涵盖参与昆虫黑色素与眼黄素生物合成通路的已知基因，以及潜在参与鳞片结构形成的疑似功能组分。实验整体设计：在蛹发育后期（此时眼黄素与黑色素色素均已开始显现），分别采集蛱蝶科蝴蝶的前翅与后翅样本；野生型与optix敲除表型各设置两组生物学重复，采用Illumina Nexseq 500平台进行36 bp双端测序。