RESUMO
The Notch signaling pathway is an evolutionary conserved mechanism that plays an important role in cell-cell communication and cell fate in a wide range of tissues. The mammalian family of Notch receptors consists of 4 members: Notch1/2/3/4. The Notch ligand family consists of 5 members: Delta1/3/4 and Jagged1/2. Math1 encodes a murine Basic helix-loop-helix (bHLH) transcription factor that acts as positive regulator of cell differentiation. Recently, links between Notch and Math1 pathways were demonstrated in various tissues. Expression of Notch1, Jagged2 and Math1 were analyzed in the mouse molar tooth germ during embryonic stage (E) 13 and E15 and during postnatal stage (PN) 1, PN3, PN5, PN10 and PN14 by using in situ hybridization. Positive Notch1 expression was found at the tooth bud during embryonic stages, but its expression was absent from the basal cells in contact with the dental mesenchyme. Jagged2 and Math1 were strongly expressed in differentiated ameloblasts and odontoblasts and Math1 strong expression was even maintained until PN14 stage. Math1 showed the strongest expression. Our results suggest that the Notch1 signaling pathway through Jagged2 could be importantly related to Math1, directing the process of odontogenesis toward cell differentiation.(AU)
Assuntos
Animais , Ratos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Transdução de Sinais/fisiologia , Germe de Dente/citologia , Germe de Dente/fisiologia , Camundongos Endogâmicos BALB C , Dente Molar/anatomia & histologia , Dente Molar/fisiologia , Odontogênese/fisiologia , Receptor Notch1/genética , Receptor Notch1/metabolismoRESUMO
The Notch signaling pathway is an evolutionary conserved mechanism that plays an important role in cell-cell communication and cell fate in a wide range of tissues. The mammalian family of Notch receptors consists of 4 members: Notch1/2/3/4. The Notch ligand family consists of 5 members: Delta1/3/4 and Jagged1/2. Math1 encodes a murine Basic helix-loop-helix (bHLH) transcription factor that acts as positive regulator of cell differentiation. Recently, links between Notch and Math1 pathways were demonstrated in various tissues. Expression of Notch1, Jagged2 and Math1 were analyzed in the mouse molar tooth germ during embryonic stage (E) 13 and E15 and during postnatal stage (PN) 1, PN3, PN5, PN10 and PN14 by using in situ hybridization. Positive Notch1 expression was found at the tooth bud during embryonic stages, but its expression was absent from the basal cells in contact with the dental mesenchyme. Jagged2 and Math1 were strongly expressed in differentiated ameloblasts and odontoblasts and Math1 strong expression was even maintained until PN14 stage. Math1 showed the strongest expression. Our results suggest that the Notch1 signaling pathway through Jagged2 could be importantly related to Math1, directing the process of odontogenesis toward cell differentiation.
Assuntos
Animais , Ratos , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Regulação da Expressão Gênica no Desenvolvimento , Germe de Dente/citologia , Germe de Dente/fisiologia , Camundongos Endogâmicos BALB C , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Transdução de Sinais/fisiologia , Dente Molar/anatomia & histologia , Dente Molar/fisiologia , Odontogênese/fisiologia , Receptor Notch1/genética , Receptor Notch1/metabolismoRESUMO
A series of experiments were conducted to evaluate the toxicity of lemon peel extracts incorporated into mediterranean fruit fly Ceratitis capitata diet. Extracts were obtained with different solvents: diethyl ether, ethyl acetate, and methanol. All three extracts were toxic to some extent; the diethyl ether extract was selected for further studies. Ether extracts of lemon peel were prepared weekly over a 2-month period, from fruits collected on the 1st d of the bioassay. Weekly GC-MS and UV analyses of the extracts demonstrated that the concentration of citral and coumarins decreased in the peel after harvest. We conducted a series of bioassays to evaluate the toxicity of the ether extract, and mixtures of this extract with citral, 5,7-dimethoxycoumarin. and linalool incorporated to C. capitata larvae's natural diet (lemon slices endocarp) at a concentration of 250 microg/g of diet. Significant larvicidal activity can be obtained from a fresh lemon peel extract; however, when the extract was obtained from stored lemons, toxicity decreased. Addition of small amounts of citral or 5,7-dimethoxycoumarin, and linalool to the stored lemon peel extract would bring back the toxicity to the rates of fresh lemons extracts. Finally, female adults of C. capitata fed on diets containing additional amounts of ether extract, 5,7-dimethoxycoumarin, and linalool, were exposed to different photoperiods to test for phototoxicity. The treatment was toxic and affected the oviposition capacity of females depending on photoperiod.