Dataset Information

Intragenomic variations of multicopy ITS2 marker in Agrodiaetus blue butterflies (Lepidoptera, Lycaenidae).

ABSTRACT: The eukaryotic ribosomal DNA cluster consists of multiple copies of three genes, 18S, 5. 8S and 28S rRNAs, separated by multiple copies of two internal transcribed spacers, ITS1 and ITS2. It is an important, frequently used marker in both molecular cytogenetic and molecular phylogenetic studies. Despite this, little is known about intragenomic variations within the copies of eukaryotic ribosomal DNA genes and spacers. Here we present data on intraindividual variations of ITS2 spacer in three species of Agrodiaetus Hübner, 1822 blue butterflies revealed by cloning technique. We demonstrate that a distinctly different intragenomic ITS2 pattern exists for every individual analysed. ITS2 sequences of these species show significant intragenomic variation (up to 3.68% divergence), setting them apart from each other on inferred phylogenetic tree. This variation is enough to obscure phylogenetic relationships at the species level.

SUBMITTER: Shapoval NA

PROVIDER: S-EPMC4698565 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Intragenomic variations of multicopy ITS2 marker in Agrodiaetus blue butterflies (Lepidoptera, Lycaenidae).

Shapoval Nazar A NA Lukhtanov Vladimir A VA

Comparative cytogenetics 20150807 4

The eukaryotic ribosomal DNA cluster consists of multiple copies of three genes, 18S, 5. 8S and 28S rRNAs, separated by multiple copies of two internal transcribed spacers, ITS1 and ITS2. It is an important, frequently used marker in both molecular cytogenetic and molecular phylogenetic studies. Despite this, little is known about intragenomic variations within the copies of eukaryotic ribosomal DNA genes and spacers. Here we present data on intraindividual variations of ITS2 spacer in three spe ...[more]

PMID: 26753069

Similar Datasets

Project description:BACKGROUND: Current molecular phylogenetic studies of Lepidoptera and most other arthropods are predominantly based on mitochondrial genes and a limited number of nuclear genes. The nuclear genes, however, generally do not provide sufficient information for young radiations. ITS2 , which has proven to be an excellent nuclear marker for similarly aged radiations in other organisms like fungi and plants, is only rarely used for phylogeny estimation in arthropods, although universal primers exist. This is partly due to difficulties in the alignment of ITS2 sequences in more distant taxa. The present study uses ITS2 secondary structure information to elucidate the phylogeny of a species-rich young radiation of arthropods, the butterfly subgenus Agrodiaetus. One aim is to evaluate the efficiency of ITS2 to resolve the phylogeny of the subgenus in comparison with COI , the most important mitochondrial marker in arthropods. Furthermore, we assess the use of compensatory base changes in ITS2 for the delimitation of species and discuss the prospects of ITS2 as a nuclear marker for barcoding studies. RESULTS: In the butterfly family Lycaenidae, ITS2 secondary structure enabled us to successfully align sequences of different subtribes in Polyommatini and produce a Profile Neighbour Joining tree of this tribe, the resolution of which is comparable to phylogenetic trees obtained with COI+COII . The subgenus Agrodiaetus comprises 6 major clades which are in agreement with COI analyses. A dispersal-vicariance analysis (DIVA) traced the origin of most Agrodiaetus clades to separate biogeographical areas in the region encompassing Eastern Anatolia, Transcaucasia and Iran. CONCLUSIONS: With the inclusion of secondary structure information, ITS2 appears to be a suitable nuclear marker to infer the phylogeny of young radiations, as well as more distantly related genera within a diverse arthropod family. Its phylogenetic signal is comparable to the mitochondrial marker COI . Compensatory base changes are very rare within Polyommatini and cannot be used for species delimitation. The implementation of secondary structure information into character-based phylogenetic methods is suggested to further improve the versatility of this marker in phylogenetic studies.

Project description:The Balkan Peninsula represents one of the hottest biodiversity spots in Europe. However, the invertebrate fauna of this region is still insufficiently investigated, even in respect of such well-studied organisms as Lepidoptera. Here we use a combination of chromosomal, molecular and morphological markers to rearrange the group of so-called anomalous blue butterflies (also known as 'brown complex' of the subgenus Agrodiaetus Hübner, [1822] and as the Polyommatus (Agrodiaetus) admetus (Esper, 1783) species group) and to reveal its cryptic taxonomic structure. We demonstrate that Polyommatus aroaniensis (Brown, 1976) is not as widespread in the Balkans as was previously thought. In fact, it has a dot-like distribution range restricted to the Peloponnese Peninsula in South Greece. Polyommatus orphicus Kolev, 2005 is not as closely related to the Turkish species Polyommatus dantchenkoi (Lukhtanov & Wiemers, 2003) as was supposed earlier. Instead, it is a Balkan endemic represented by two subspecies: Polyommatus orphicus orphicus (Bulgaria) and Polyommatus orphicus eleniae Coutsis & De Prins, 2005 (Northern Greece). Polyommatus ripartii (Freyer, 1830) is represented in the Balkans by an endemic subspecies Polyommatus ripartii pelopi. The traditionally recognized Polyommatus admetus (Esper, 1783) is shown to be a heterogeneous complex and is divided into Polyommatus admetus sensu stricto (the Balkans and west Turkey) and Polyommatus yeranyani (Dantchenko & Lukhtanov, 2005) (east Turkey, Armenia, Azerbaijan and Iran). Polyommatus nephohiptamenos (Brown & Coutsis, 1978) is confirmed to be a species with a dot-like distribution range in Northern Greece. Finally, from Central Greece (Timfristos and Parnassos mountains) we describe Polyommatus timfristos Lukhtanov, Vishnevskaya & Shapoval, sp. n. which differs by its haploid chromosome number (n=38) from the closely related and morphologically similar Polyommatus aroaniensis (n=47-48) and Polyommatus orphicus (n=41-42). We provide chromosomal evidence for three separate south Balkan Pleistocene refugia (Peloponnesse, Central Greece and Northern Greece/South Bulgaria) and stress the biogeographic importance of Central Greece as a place of diversification. Then we argue that the data obtained have direct implications for butterfly karyology, taxonomy, biogeography and conservation.

Project description:BACKGROUND:Non-long terminal repeat (non-LTR) retrotransposons are mobile genetic elements that propagate themselves by reverse transcription of an RNA intermediate. Non-LTR retrotransposons are known to evolve mainly via vertical transmission and random loss. Horizontal transmission is believed to be a very rare event in non-LTR retrotransposons. Our knowledge of distribution and diversity of insect non-LTR retrotransposons is limited to a few species - mainly model organisms such as dipteran genera Drosophila, Anopheles, and Aedes. However, diversity of non-LTR retroelements in arthropods seems to be much richer. The present study extends the analysis of non-LTR retroelements to CR1 clade from four butterfly species of genus Maculinea (Lepidoptera: Lycaenidae).The lycaenid genus Maculinea, the object of interest for evolutionary biologists and also a model group for European biodiversity studies, possesses a unique, specialized myrmecophilous lifestyle at larval stage. Their caterpillars, after three weeks of phytophagous life on specific food plants drop to the ground where they are adopted to the ant nest by Myrmica foraging workers. RESULTS:We found that the genome of Maculinea butterflies contains multiple CR1 lineages of non-LTR retrotransposons, including those from MacCR1A, MacCR1B and T1Q families. A comparative analysis of RT nucleotide sequences demonstrated an extremely high similarity among elements both in interspecific and intraspecific comparisons. CR1A-like elements were found only in family Lycaenidae. In contrast, MacCR1B lineage clones were extremely similar to CR1B non-LTR retrotransposons from Bombycidae moths: silkworm Bombyx mori and Oberthueria caeca. CONCLUSION:The degree of coding sequence similarity of the studied elements, their discontinuous distribution, and results of divergence-versus-age analysis make it highly unlikely that these sequences diverged at the same time as their host taxa. The only reasonable alternative explanation is horizontal transfer. In addition, phylogenetic markers for population analysis of Maculinea could be developed based on the described non-LTR retrotransposons.

Dataset Information

Intragenomic variations of multicopy ITS2 marker in Agrodiaetus blue butterflies (Lepidoptera, Lycaenidae).

Publications

Intragenomic variations of multicopy ITS2 marker in Agrodiaetus blue butterflies (Lepidoptera, Lycaenidae).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure