Females of the Indian meal moth, Plodia interpunctella, and females of the Mediterranean flour month, Ephestia kuehniella (both Lepidoptera: Pyralidae), exhibit daily rhythms in calling behavior. The peak in P. interpunctella calling occurs at dusk, whereas E. kuehniella calls preferentially at dawn. This behavior turned arrhythmic in P. interpunctella females in constant darkness (DD) and remained arrhythmic in constant light (LL), whereas E. kuehniella females showed a persistent rhythm in DD and suppression of the behavior in LL, indicating regulation by a circadian clock mechanism. The rhythm of male locomotor activity corresponded well with the sexual activity of females, reaching the peak at dusk in P. interpunctella and at dawn in E. kuehniella. An immunohistochemical study of the pheromone biosynthesis activating neuropeptide, corazonin, and pigment dispersing factor revealed distinct sets of neurons in the brain-subesophageal complex and in the neurohemal organs of the 2 species.

• MeSH
• biologické modely MeSH
• cirkadiánní rytmus MeSH
• druhová specificita MeSH
• feromony metabolismus   MeSH
• hmyz MeSH
• hormony metabolismus   MeSH
• imunohistochemie metody   MeSH
• komunikace zvířat MeSH
• můry fyziologie   MeSH
• neuropeptidy chemie   MeSH
• pigmentace MeSH
• sexuální chování zvířat MeSH
• sexuální faktory MeSH
• sexuální lákadla MeSH
• světlo MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Sex determination in the silkworm, Bombyx mori, is based on Feminizer (Fem), a W-linked Fem piRNA that triggers female development in WZ individuals, and the Z-linked Masculinizer (Masc), which initiates male development and dosage compensation in ZZ individuals. While Fem piRNA is missing in a close relative of B. mori, Masc determines sex in several representatives of distant lepidopteran lineages. We studied the molecular mechanisms of sex determination in the Mediterranean flour moth, Ephestia kuehniella (Pyralidae). We identified an E. kuehniella Masc ortholog, EkMasc, and its paralog resulting from a recent duplication, EkMascB. Both genes are located on the Z chromosome and encode a similar Masc protein that contains two conserved domains but has lost the conserved double zinc finger domain. We developed PCR-based genetic sexing and demonstrated a peak in the expression of EkMasc and EkMascB genes only in early male embryos. Simultaneous knock-down experiments of both EkMasc and EkMascB using RNAi during early embryogenesis led to a shift from male- to female-specific splicing of the E. kuehniella doublesex gene (Ekdsx), their downstream effector, in ZZ embryos and resulted in a strong female-biased sex-ratio. Our results thus confirmed the conserved role of EkMasc and/or EkMascB in masculinization. We suggest that the C-terminal proline-rich domain, we have identified in all functionally confirmed Masc proteins, in conjunction with the masculinizing domain, is important for transcriptional regulation of sex determination in Lepidoptera. The function of the Masc double zinc finger domain is still unknown, but appears to have been lost in E. kuehniella.

• MeSH
• alternativní sestřih MeSH
• duplikace genu * MeSH
• hmyzí proteiny chemie   genetika   MeSH
• kompenzace dávky (genetika) MeSH
• můry embryologie   genetika   MeSH
• orgánová specificita MeSH
• pohlavní chromozomy genetika   MeSH
• procesy určující pohlaví MeSH
• proteinové domény MeSH
• stanovení celkové genové exprese MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Homologous circadian genes are found in all insect clocks, but their contribution to species-specific circadian timing systems differs. The aim of this study was to extend research within Lepidoptera to gain a better understanding of the molecular mechanism underlying circadian clock plasticity and evolution. The Mediterranean flour moth, Ephestia kuehniella (Pyralidae), represents a phylogenetically ancestral lepidopteran species. We have identified circadian rhythms in egg hatching, adult emergence, and adult locomotor activity. Cloning full-length complementary DNAs and further characterization confirmed one copy of period and timeless genes in both sexes. Both per and tim transcripts oscillate in their abundance in E. kuehniella heads under light-dark conditions. PER-like immunoreactivity (PER-lir) was observed in nuclei and cytoplasm of most neurons in the central brain, the ventral part of subesophageal complex, the neurohemal organs, the optic lobes, and eyes. PER-lir in photoreceptor nuclei oscillated during the day with maximal intensity in the light phase of the photoperiodic regime and lack of a signal in the middle of the dark phase. Expression patterns of per and tim messenger RNAs (mRNAs) were revealed in the identical location as the PER-lir was detected. In the photoreceptors, a daily rhythm in the intensity of expression of both per mRNA and tim mRNA was found. These findings suggest E. kuehniella as a potential lepidopteran model for circadian studies.

• MeSH
• biologické hodiny genetika   MeSH
• cirkadiánní hodiny genetika   MeSH
• cirkadiánní proteiny Period genetika   metabolismus   MeSH
• cirkadiánní rytmus genetika   fyziologie   MeSH
• fenotyp MeSH
• fotoperioda MeSH
• hmyzí proteiny genetika   MeSH
• hybridizace in situ MeSH
• imunohistochemie MeSH
• jaderné proteiny metabolismus   MeSH
• klonování organismů MeSH
• komplementární DNA MeSH
• messenger RNA genetika   metabolismus   MeSH
• mozek metabolismus   MeSH
• můry genetika   růst a vývoj   fyziologie   MeSH
• regulace genové exprese MeSH
• sekvenční analýza DNA MeSH
• světlo MeSH
• zrakový lalok nesavčí fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• chromozomální aberace MeSH
• infertilita genetika   MeSH
• Lepidoptera genetika   MeSH
• pohlavní dimorfismus MeSH
• radiační účinky MeSH

• MeSH
• fenotyp MeSH
• můry genetika   MeSH
• mutace MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

• MeSH
• genetické markery MeSH
• meióza fyziologie   MeSH
• můry fyziologie   genetika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH

Moths and butterflies (Lepidoptera) are the most species-rich group of animals with female heterogamety, females mostly having a WZ, males a ZZ sex chromosome constitution. We studied chromatin conformation, activity, and inactivity of the sex chromosomes in the flour moth Ephestia kuehniella and the silkworm Bombyx mori, using immunostaining with anti-H3K9me2/3, anti-RNA polymerase II, and fluoro-uridine (FU) labelling of nascent transcripts, with conventional widefield fluorescence microscopy and 'spatial structured illumination microscopy' (3D-SIM). The Z chromosome is euchromatic in somatic cells and throughout meiosis. It is transcriptionally active in somatic cells and in the postpachaytene stage of meiosis. The W chromosome in contrast is heterochromatic in somatic cells as well as in meiotic cells at pachytene, but euchromatic and transcriptionally active like all other chromosomes at postpachytene. As the W chromosomes are apparently devoid of protein-coding genes, their transcripts must be non-coding. We found no indication of 'meiotic sex chromosome inactivation' (MSCI) in the two species.

• MeSH
• bourec genetika   metabolismus   MeSH
• chromatin metabolismus   MeSH
• chromozomy hmyzu metabolismus   MeSH
• meióza MeSH
• můry genetika   metabolismus   MeSH
• pohlavní chromozomy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH