The transcription factor Apontic-like controls diverse colouration pattern in caterpillars

Abstract

Genetic polymorphisms underlie the convergent and divergent evolution of various phenotypes. Diverse colour patterns on caterpillars, which are ecologically important, are good models for understanding the molecular backgrounds of phenotypic diversity. Here we show that a single evolutionarily conserved gene apontic-like (apt-like) encoding for a putative transcription factor accounts for the silkworm p locus, which causes at least 15 different larval markings involved in branch-like markings and eye-spot formation. The expression of apt-like and melanin synthesis genes are upregulated in association with pigmented areas of marking mutants Striped (p S ) and normal ( þ p ) but not in the non-marking allele plain (p). Functional analyses, ectopic expression, RNAi and TALEN, demonstrate that apt-like causes melanin pigmentation in a cell-autonomous manner. These results suggest that variation in p alleles is caused by the differential expression of the gene apt-like which induces targeted elevation of gene expressions in the melanin synthesis pathway.

Melanism patches up the defective cuticular morphological traits through promoting the up-regulation of cuticular protein-coding genes in Bombyx mori

“…Wild-type strains Dazao ( + p ) and melanic mutant strains p M , p S and p B (Xiang 1995; Banno et al 2005; Yoda et al 2014) were analyzed in this study. The darkness of pigment was measured as mean OD value using Image J (https://imagej.nih.gov/ij/).…”

“…Besides this, there are also multiple alleles with different melanism degrees at the p locus, including p B , p M , etc (Xiang 1995; Banno et al . 2005; Yoda et al . 2014).…”

“…In the Lepidoptera model, Bombyx mori , an intriguing phenomenon has been reported that a larval melanic mutant, Striped ( p S , 2-0.0) is able to rehabilitate the malformed body shape, as well as the adaptability defects of the stony mutant ( st , 8-0.0) (Xiang 1995; Banno et al 2005). A recent study clarified that a transcription factor, Apontic-like , which boosts the expression of melanin synthesis genes in epidermal cells, is responsible for the p S mutant (Yoda et al 2014). Besides this, there are also multiple alleles with different melanism degrees at the p locus, including p B , p M , etc (Xiang 1995; Banno et al 2005; Yoda et al 2014).…”

Genome editing in Bombyx mori: New opportunities for silkworm functional genomics and the sericulture industry

“…Liu et al (2018Liu et al ( , 2019 showed that the disruption of BmTCTP led to developmental arrest and subsequent lethality in 3rd instar larvae, indicating a key role of BmTCTP in controlling larval growth and development. Several candidate genes found by positional cloning of B. mori mutants were verified by TALENs or CRISPR/Cas9 (Yoda et al, 2014;Osanai-Futahashi et al, 2016;Xiong et al, 2017).…”

CRISPR/Cas9‐based mutation reveals Argonaute 1 is essential for pigmentation in Ostrinia furnacalis

“…In addition, our result also proved the conserved role of Ago1 among insect species. To explain the phenotype caused by disruption of OfAgo1, we also examined the transcription of four pigment patterning-related genes including the Abdominal-A (Abd-A), wingless 1 (Wnt1), Distal-less (Dll) and Apt-like in the epidermis (Beldade et al, 2002;Yamaguchi et al, 2013;Rogers et al, 2014;Yoda et al, 2014; Fig. 5B).…”