RESUMO
RAPD-analysis was used to estimate intraspecies-specific variability in malaria mosquitoes, the major vectors of malaria in Central Asia. The high heterogeneity of RAPD-loci was found in 7 populations of An. superpictus and 2 populations of An. pulcherrimus. Genetic distances between the populations were determined on the basis of analysis of the frequencies of 15 RAPD-loci. There was a genetic similarity of An. superpictus populations in the malaria foci of Tadjikistan with those in the neighboring Surkhandariya Region of Uzbekistan.
Assuntos
Anopheles/classificação , Insetos Vetores/classificação , Malária/parasitologia , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Animais , Anopheles/genética , Anopheles/crescimento & desenvolvimento , Primers do DNA , Genes de Insetos/genética , Insetos Vetores/genética , Insetos Vetores/crescimento & desenvolvimento , Larva/genética , Malária/prevenção & controle , Especificidade da Espécie , Tadjiquistão , UzbequistãoRESUMO
Diploid gynogenetic progenies were obtained in the stellate sturgeon Acipenser stellatus, Russian sturgeon A. gueldenstaedtii, and sterlet A. ruthenus by means of insemination of the eggs with UV-irradiated spermatozoa and suppression of the second meiotic division by heat shock. The gynogenetic nature of experimental fish was confirmed by RAPD-PCR analysis of DNA. Effective photoreactivation of UV-induced lesions of spermatozoa was shown in the case of illumination of the fertilized eggs with visible light. This phenomenon should be taken into account when determining the doses of irradiation that allow inactivation of the male chromosomes and incubating gynogenetic embryos. Gynogenetic stellate and Russian sturgeons are viable and can be reared in order to study the mechanism of sex determination in sturgeons.
Assuntos
Peixes/genética , Meiose , Partenogênese/genética , Animais , Cromossomos/efeitos da radiação , Diploide , Relação Dose-Resposta à Radiação , Embrião não Mamífero , Feminino , Peixes/embriologia , Resposta ao Choque Térmico , Inseminação Artificial/métodos , Masculino , Técnica de Amplificação ao Acaso de DNA Polimórfico , Processos de Determinação Sexual , Espermatozoides/efeitos da radiação , Raios UltravioletaRESUMO
Intra- and interspecific variability of total DNA isolated from haploid megagametophytes of coniferous species was examined using polymerase chain reaction with random primers. Based on this technique, one can with certainty detect heterozygosity at gene loci carrying null alleles and thus reveal cryptic intraspecific genetic variation. Large population samples were used. Along with random amplified polymorphic DNA, i.e., widely known fragments (amplicons) polymorphic within a species, we found invariant loci lacking individual or geographic variability but differentiating species within genera and other taxa. This DNA was termed RAMD (random amplified monomorphic DNA) to distinguish it from polymorphic DNA. Our findings suggest that genetic monomorphism of species and the dual structure of the eukaryotic genome can be detected at the DNA level as was previously shown for protein gene markers.
