title: Identification of the silkworm quail gene reveals a crucial role of a receptor guanylyl cyclase in larval pigmentation.
abstract: Diverse color patterns on the integument of lepidopteran larvae play important roles in their survival through camouflage, mimicry, sexual signaling, and aposematism. In the silkworm Bombyx mori, many color pattern variations have been preserved in inbred strains making them a good model for elucidating the molecular mechanisms that underlie color pattern formation. In this study, we focused on the silkworm quail (q) mutant, which exhibits abnormalities in multiple pigment biosynthesis pathways. Positional cloning of the q gene revealed that disruption of a guanylyl cyclase gene, BmGC-I, is responsible for its abnormal pigmentation. In q mutants, we identified a 16-bp deletion in the BmGC-I transcript, resulting in the production of a premature stop codon. Knockout of the BmGC-I gene resulted in the q-like abnormal pigmentation, thereby demonstrating that the BmGC-I gene is involved in the pigment biosynthesis pathway in the integument. Moreover, quantitative reverse transcription polymerase chain reaction showed that BmGC-I was strongly expressed in the fourth instar on day 2. Our results suggest that BmGC-I deficiency affects the pigment biosynthesis pathway, which supports the involvement of guanylyl cyclase in larval coloration.
authors.affiliation: Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yuasa
authors.affiliation: Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kiuchi
authors.affiliation: Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Banno
authors.affiliation: Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Katsuma
authors.affiliation: Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan. Electronic address: shimada@ss.ab.a.u-tokyo.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Shimada
mesh_terms: D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D003001:Cloning, Molecular; D004247:DNA; D005260:Female; D055786:Gene Knockout Techniques; D017344:Genes, Insect; D007814:Larva / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics; D011784:Quail; D050705:Receptors, Guanylate Cyclase-Coupled / Q000502:physiology*; D059467:Transcriptome
chemical_list: D004247:DNA; D050705:Receptors, Guanylate Cyclase-Coupled
keywords: Bombyx mori; Guanylyl cyclase; Integument; Melanin; Pigmentation