RESUMO
Spontaneous mutations are thought to have a stable rate for a given species. If non-adaptive, they appear at low frequencies and are governed by drift. However, environmental factors have been reported to cause spread of non-adaptive mutations in populations, governed by mechanisms, such as genetic assimilation. In the present study, we report a simultaneous appearance of a mutant and apparently non-adaptive C2 vein in Drosophila melanogaster at higher than expected frequencies in several distant populations, which excludes the role of drift or selection as the cause of the reported mutation frequencies. We discuss explanations of the phenomenon, including the role of externalfactors, such as temperature, in the possible genetic assimilation of the trait.
Assuntos
Drosophila melanogaster/anatomia & histologia , Drosophila melanogaster/genética , Deriva Genética , Mutação , Seleção Genética , Adaptação Fisiológica/genética , Animais , Drosophila melanogaster/crescimento & desenvolvimento , Ucrânia , Asas de Animais/anatomia & histologiaRESUMO
OBJECTIVE: To estimate frequencies of polymorphic variants of TP53 codon 72 in the Ukrainian population. MATERIALS AND METHODS: We determined the allele frequencies for 148 healthy people. Genotyping was performed by allele specific polymerase chain reaction. RESULTS: We identified 31 individuals (20.9 %) with Arg/Arg genotype, Arg/Pro genotype was identified for 116 indi viduals (78.4 %), whereas genotype Pro/Pro was rare and was found in one person only (0.7 %). Genotype distribu tions were not within Hardy Weinberg equilibrium (χ2 = 59,7, p < 0.0001). CONCLUSIONS: Arg and Pro allele frequencies in the population of Ukraine are 60 and 40 % respectively, which is sig nificantly differ from the frequencies described in the literature for Poland, the Czech Republic, the USA and Brazil.
RESUMO
During maturation Drosophila wing epithelial cells undergo number of changes due to processes, which take place in the wing of the newly emerged fly, among which epithelial-to-mesenchymal transition (EMT) and apoptosis are pivotal. It is considered that neurohormone bursicon is responsible for their triggering. In turn, extracellular matrix protein Miniature is also essential for proper progress of apoptosis and, presumably, EMT. In accordance with our previously proposed hypothesis, Miniature and bursicon form stabilizing/accumulative complexes, which are able to diffuse freely within Drosophila wing, in such a way constitutively promoting enough concentrations of the maturation triggering signal. Here we tried to come to confirmation of our hypothesis from the other side, using UAS/GAL4 system and RNAi-silencing techniques.
Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Transição Epitelial-Mesenquimal/genética , Regulação da Expressão Gênica , Proteínas de Membrana/genética , Asas de Animais/crescimento & desenvolvimento , Animais , Regulação para Baixo , Drosophila melanogaster/crescimento & desenvolvimento , Hormônios de Invertebrado/genética , Fenótipo , Interferência de RNA , Fatores de Transcrição/genética , Asas de Animais/metabolismoRESUMO
In the present review, an association between cancer and the activity of the non-LTR retroelements L1, Alu, and SVA, as well as endogenous retroviruses, in the human genome, is analyzed. Data suggesting that transposons have been involved in embryogenesis and malignization processes, are presented. Events that lead to the activation of mobile elements in mammalian somatic cells, as well as the use of mobile elements in genetic screening and cancer gene therapy, are reviewed.
