Wyniki wyszukiwania

Filtruj wyniki

  • Czasopisma
  • Autorzy
  • Słowa kluczowe
  • Data
  • Typ

Wyniki wyszukiwania

Wyników: 2
Wyników na stronie: 25 50 75
Sortuj wg:

Abstrakt

Until recently, Festuca arietina was practically an unknown species in the flora of Eastern Europe. Such a situation can be treated as a consequence of insufficient studying of Festuca valesiaca group species in Eastern Europe and misinterpretation of the volume of some taxa. As a result of a complex study of F arietina populations from the territory of Ukraine (including the material from locus classicus), Belarus and Lithuania, original anatomy, morphology and molecular data were obtained. These data confirmed the taxonomical status of F arietina as a separate species. Eleven morphological and 12 anatomical characters, ITS1-5.8S-ITS2 cluster of nuclear ribosomal genes, as well as the models of secondary structure of ITS1 and ITS2 transcripts were studied in this approach. It was found for the first time that F arietina is hexaploid (6x = 42), which is distinguished from all the other narrow-leaved fescues by specific leaf anatomy as well as in ITS1-5.8S-ITS2 sequences. Molecular data indicating possible hybridogenous origin of F arietina, fall in line with the anatomical-morphological data and explain the tendency toward sclerenchyma strands fusion with formation of a continuous ring in F arietina, as well as E arietina ecological confinement to psammophyte biotopes.
Przejdź do artykułu

Abstrakt

The current study is the first phylogenetic and secondary RNA structure analysis of Dactylogyrus species parasitising gill filaments of Iraqi cyprinid fishes. Most previous phylogenetic studies have targeted on primary DNA sequence data. Nevertheless, RNA secondary configuration is principally helpful in systematics since they comprise features that do not appear in the primary sequence and provide morphological information. The primary objective was molecular-based identification of Dactylogyrids species using evolutionary tree and secondary RNA structure prediction. A total of 681 fish were collected from the Lesser Zab River in the northeast of Iraq in the sub-district of Altun-Kopru from August 2016 to September 2017 and brought to the Zoology Research Laboratory, Salahaddin University-Erbil, Iraq. All fish were classified as 18 cyprinid species. The species of Dactylogyrus were identified by the 28S rDNA subunit using PCR and sequencing methods, and the obtained nucleotide sequences were then compared with the available GenBank sequences. Phylogenetic relationships were concluded using Neighbour-Joining (NJ), Maximum Likelihood (ML), and Minimum Evolution (ME) methods. The results justify the validation of 11 Dactylogyrus species (three of them were newly recorded in Iraq). Additionally, out of nine infected fish species, seven of them were regarded as a new host for Dactylogyrus species. Secondary RNA configuration prediction using minimum free energy was considered as a hopeful tool for species identification. This was considered the first comprehensive phylogenetic study in the area. It was concluded that PCR sequencing, phylogenetic and secondary RNA analysis were proper molecular methods for identifying Dactylogyrids species on the gills of fishes.
Przejdź do artykułu

Ta strona wykorzystuje pliki 'cookies'. Więcej informacji