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Pax genes are crucial for eye development in various organisms including Drosophila melanogaster. Eye gone (eyg) is one of the Pax genes and is involved in head and eye development in Drosophila. Eye missing (eym) is known as a recessive mutation that shows an eye-loss phenotype. Although the responsible gene was mapped as 3-67.9 on the recombination map, the gene and the molecular mechanism inducing its phenotype have not been clarified. Here we show that eym¹ has a nucleotide replacement in the eyg intron and that much of the CD enhancer required for the eyg expression in the second instar larvae is deleted. The eyg mRNA expression is drastically reduced in the second instar eym¹ mutants and eyg overexpression compensates for the eym eye-loss phenotype. In eym eye discs, cell proliferation and neural cell differentiation is inhibited. The wg protein is misexpressed in the dorsoventral compartment boundary in eym¹ eye discs. Taking these data together, we demonstrate that eym is a new allele of eyg, thus eygeym, and the reduction of eyg transcription in the second instar larvae causes an eye-loss phenotype via the deletion of its enhancer. [ABSTRACT FROM AUTHOR]

Current populations of the wild mulberry silkworm, Bombyx mandarina Moore (Lepidoptera: Bombycidae), inhabiting Japan were previously shown to be divided in four groups by a genetic variation in the mitochondrial cytochrome c oxidase subunit I (COI) gene. According to the geographic divisions, their phylogeographic natures were suggested to be involved in those of the mulberry trees. This hypothesis was based on a data set of many samples collected from 2008 to 2016, although it is not obvious whether such a compilation is appropriate to depict a snapshot of genetic variation of B. mandarina populations in a wide range. For understanding spatial and temporal stability of the mitochondrial DNA (mtDNA) haplotypes in those populations, we examined the frequencies of COI haplotypes in current populations. The geographic boundary between the genetic groups 1 and 2 was similarly detected in Kansai as previously found. In addition, the frequency of COI haplotypes were shown to be inherited stably for at least seven generations in a population, despite of neighbor populations carrying quite different haplotypes. These results support the previous picture of the geographic distribution pattern of COI haplotypes in B. mandarina in Japan. [ABSTRACT FROM AUTHOR]