RESUMO
Phylogenetic analysis of large subunit ribosomal RNA (LSU rRNA or 28S rRNA) gene sequences from free-living predatory flagellates Colpodella angusta, Voromonas pontica, and Alphamonas edax (Apicomplexa) confirms their close relationship with chromerids Chromera velia and Vitrella brassicaformis, which possess a functional photosynthetic plastid. Together these organisms form a sister group to parasitic apicomplexans (coccidians and gregarines, or sporozoans sensu lato). This result agrees with the previous conclusion on monophyly of colpodellids and chromerids (chrompodellids) based on phylogenomic data. The revealed relationships demonstrate a complex pattern of acquisition, loss, or modification of plastids and transition to parasitism during alveolate evolution.
Assuntos
Alveolados/classificação , Alveolados/genética , Filogenia , RNA Ribossômico/genética , Sequência de Bases , Teorema de Bayes , Plastídeos/genética , RNA Ribossômico/classificação , Análise de Sequência de DNARESUMO
The genetic consequences of irradiation were studied in a Scots pine population from a region contaminated as a result of the Chernobyl meltdown. Mutations of isozyme loci were not detected in seeds collected from trees of the first post-meltdown generation in 2004. The frequency of cells with chromosome aberrations in the root meristem of seedlings grown from the seeds did not differ from the control level. A deviation from the expected ratio 1:1 was observed for some isozyme alleles in endosperms of seeds obtained from heterozygous trees.
Assuntos
Acidente Nuclear de Chernobyl , Aberrações Cromossômicas/efeitos da radiação , Pinus sylvestris/genética , Locos de Características Quantitativas/efeitos da radiação , Poluentes Radioativos , Meristema/citologia , Meristema/metabolismo , Pinus sylvestris/citologia , Pinus sylvestris/metabolismo , Locos de Características Quantitativas/genéticaRESUMO
Correlation between body length and characteristics of genetic polymorphism for loci Me-2, IDHP-3, ESTD-1, and AAT-2 were studied in the Atlantic salmon Salmo salar. The study was based on data on genetic variation in more than 4000 fish grown at the Kandalaksha Hatchery. Of four loci studied, loci ESTD-1 and IDHP-3 were distinguished by the fact that they can be confidently considered body-length markers in the Atlantic salmon. Analysis of mean locus heterozygosity indicates a disturbance of the mechanism of negative heterosis that is characteristic of natural populations. This presumably reflects a change in the genetic diversity of the Atlantic salmon under the influence of breeding.