State Key Laboratory of Resource Insects, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing, China.
Elife. 2024 Apr 8;12:RP90795. doi: 10.7554/eLife.90795.
The color pattern of insects is one of the most diverse adaptive evolutionary phenotypes. However, the molecular regulation of this color pattern is not fully understood. In this study, we found that the transcription factor Bm-mamo is responsible for () allele mutations in the silkworm. Bm-mamo belongs to the BTB zinc finger family and is orthologous to mamo in . This gene has a conserved function in gamete production in and silkworms and has evolved a pleiotropic function in the regulation of color patterns in caterpillars. Using RNAi and clustered regularly interspaced short palindromic repeats (CRISPR) technology, we showed that Bm-mamo is a repressor of dark melanin patterns in the larval epidermis. Using in vitro binding assays and gene expression profiling in wild-type and mutant larvae, we also showed that Bm-mamo likely regulates the expression of related pigment synthesis and cuticular protein genes in a coordinated manner to mediate its role in color pattern formation. This mechanism is consistent with the dual role of this transcription factor in regulating both the structure and shape of the cuticle and the pigments that are embedded within it. This study provides new insight into the regulation of color patterns as well as into the construction of more complex epidermal features in some insects.
昆虫的颜色模式是最具多样性的适应性进化表型之一。然而，这种颜色模式的分子调控机制尚不完全清楚。在本研究中，我们发现转录因子 Bm-mamo 负责家蚕 () 等位基因突变。Bm-mamo 属于 BTB 锌指家族，在家蚕中与 mamo 同源。该基因在 和家蚕的配子生成中具有保守功能，并在幼虫体色模式的调控中进化出了多效性功能。我们利用 RNAi 和成簇规律间隔短回文重复序列 (CRISPR) 技术，证明 Bm-mamo 是幼虫表皮深色黑色素模式的抑制因子。通过体外结合实验和野生型及突变型幼虫的基因表达谱分析，我们还表明 Bm-mamo 可能通过协调调节相关色素合成和表皮蛋白基因的表达来发挥其在体色形成中的作用。这种机制与该转录因子在调节表皮结构和形状以及嵌入其中的色素方面的双重作用一致。本研究为颜色模式的调控以及一些昆虫中更复杂的表皮特征的构建提供了新的见解。
