GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00002667
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Bombyx mori - wild-type allele - black eyes and dark eggs
Trait State in Taxon B
Bombyx mori - pink-eyed white egg (pe) allele - red eyes and white or pale pink eggs
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Latin Name
Common Name
domestic silkworm
Synonyms
domestic silkworm; silk moth; silkworm; Bombyx mori Linnaeus, 1758
Rank
species
Lineage
Show more ... xapoda; Insecta; Dicondylia; Pterygota; Neoptera; Holometabola; Amphiesmenoptera; Lepidoptera; Glossata; Neolepidoptera; Heteroneura; Ditrysia; Obtectomera; Bombycoidea; Bombycidae; Bombycinae; Bombyx
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Latin Name
Common Name
domestic silkworm
Synonyms
domestic silkworm; silk moth; silkworm; Bombyx mori Linnaeus, 1758
Rank
species
Lineage
Show more ... xapoda; Insecta; Dicondylia; Pterygota; Neoptera; Holometabola; Amphiesmenoptera; Lepidoptera; Glossata; Neolepidoptera; Heteroneura; Ditrysia; Obtectomera; Bombycoidea; Bombycidae; Bombycinae; Bombyx
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Presumptive Null
Yes
Molecular Type
Aberration Type
SNP
SNP Coding Change
-
Molecular Details of the Mutation
Missense mutation in a conserved motif in exon 9. The tryptophan residue which is converted to arginine in the two pe strains is widely conserved in holometabolous insects.
Experimental Evidence
Taxon A Taxon B Position
Codon TGG CGG -
Amino-acid Trp Arg -
Authors
Osanai-Futahashi M; Tatematsu KI; Futahashi R; Narukawa J; Takasu Y; Kayukawa T; Shinoda T; Ishige T; et al. ... show more
Abstract
Ommochromes are major insect pigments involved in coloration of compound eyes, eggs, epidermis and wings. In the silkworm Bombyx mori, adult compound eyes and eggs contain a mixture of the ommochrome pigments such as ommin and xanthommatin. Here, we identified the gene involved in ommochrome biosynthesis by positional cloning of B. mori egg and eye color mutant pink-eyed white egg (pe). The recessive homozygote of pe has bright red eyes and white or pale pink eggs instead of a normal dark coloration due to the decrease of dark ommochrome pigments. By genetic linkage analysis, we narrowed down the pe-linked region to ~258 kb, containing 17 predicted genes. RNA sequencing analyses showed that the expression of one candidate gene, the ortholog of Drosophila haem peroxidase cardinal, coincided with egg pigmentation timing, similar to other ommochrome-related genes such as Bm-scarlet and Bm-re. In two pe strains, a common missense mutation was found within a conserved motif of B. mori cardinal homolog (Bm-cardinal). RNA interference-mediated knockdown and transcription activator-like effector nuclease (TALEN)-mediated knockout of the Bm-cardinal gene produced the same phenotype as pe in terms of egg, adult eye and larval epidermis coloration. A complementation test of the pe mutant with the TALEN-mediated Bm-cardinal-deficient strain showed that the mutant phenotype could not be rescued, indicating that Bm-cardinal is responsible for pe. Moreover, knockdown of the cardinal homolog in Tribolium castaneum also induced red compound eyes. Our results indicate that cardinal plays a major role in ommochrome synthesis of holometabolous insects.
Additional References
EXTERNAL LINKS
COMMENTS
The enzyme cardinal appears to catalyze the last step of ommin formation by using either 3-hydroxykynurenine or xanthommatin as substrates. Spontaneous mutation.
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