Dorota Lachowska-Cierlik

Conservation genetics of endangered leaf-beetle Cheilotoma musciformis populations in Poland

Steppe-like habitats in Europe are seriously threatened as a result of fragmentation and anthropogenic degradation, at least in western and central parts. Considering the dramatic loss of steppe-like habitats, the evaluation of genetic variation in populations of steppe species is of immediate importance if appropriate conservation measures are to be undertaken. In this paper, we examine the genetic diversity of the highly endangered populations of the leaf-beetle Cheilotomamusciformis, which inhabits only a limited area in south-central Poland, which is geographically isolated from the continuous range of this species. Both mitochondrial and nuclear markers show that the Polish populations are distinct from Slovakian and Ukrainian ones. These regional populations should be considered independent conservation units. On the other hand, very little (mtDNA) or no (nuclear DNA) diversity has been found among the Polish subpopulations. This leads to the conclusion that this species has gone through a strong bottleneck leading to a drastic reduction in its genetic diversity prior to the establishment of present-day populations. Host plants have been identified for this species using barcodes, and the only hosts for the Polish and Ukrainian samples are sainfoins Onobrychis spp. while for the Slovakian sample it is either Dorycniumpentaphyllum or Lotus spp. (all Fabaceae). All of these data can be very valuable for the conservation of C.musciformis populations (e.g. for reintroductions).

Genetic distinctness of parthenogenetic forms of European Polydrusus weevils of the subgenus Scythodrusus

Abstract  Among eight species of Polydrusus weevils which belong to subgenus Scythodrusus, at least two possess parthenogenetic forms: P. (S.) inustus and P. (S.) pilifer. Both of these species consist of dioecious populations in the Caspian area and of parthenogenetic populations in Eastern Europe (P. (S.) inustus), the Caucasus region (both species) and Middle Asia (P. (S.) pilifer). The origin of parthenogenesis in this subgenus is unresolved; however some data suggest that the parthenogenetic forms are of hybrid ancestry. The genetic distinctness of parthenogenetic Scythodrusus was assessed on the basis of COII, ITS2, EF1‐α and Wolbachiawsp, 16S ribosomal DNA, ftsZ and hcpA sequence comparisons. Both taxa turned out to be monophyletic for all markers, which is an evidence against hybridization of their dioecious ancestors. On the other hand, a high frequency of heterozygous P. (S.) inustus females suggests an origin resulting from hybridization between genetically distinct dioecious representatives of this species. Very similar strains of Wolbachia supergroup A were found in both species, indicating that they have been either inherited from a common ancestor or were transmitted between parthenogenetic Scythodrusus weevils and probably spread randomly across their ranges.

An integrative revision of Mesocrista Pilato, 1987 (Tardigrada: Eutardigrada: Hypsibiidae)

ABSTRACT Mesocrista is a Holarctic tardigrade genus currently classified within the subfamily Itaquasconinae (Eutardigrada: Parachela: Hypsibiidae). The position of the genus has been so far inferred solely on the basis of light microscopy observations. Here, we present the first-ever scanning electron microscopy images of a dissected bucco-pharyngeal apparatus and DNA sequences for Mesocrista from Spitsbergen, mainland Norway and Poland. The new data allowed an integrative redescription of the nominal M. spitzbergensis from the locus typicus and uncovered a new species, M. revelata, from the European localities. The two species differ phenotypically by the oral cavity armature and claw morphology as well as by a number of morphometric traits, and they are also distinct genetically in all sequenced DNA markers, three nuclear (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial (COI). Both molecular and morphometric data presented in this paper suggest that previous records of M. spitzbergensis should be treated with caution, since most probably some of them signify different Mesocrista species. Our phylogenetic analysis confirmed that Mesocrista is indeed a member of the Itaquasconinae. We also found that the most closely related, among genera for which there are molecular data available, is Adropion, from which Mesocrista differs by the shape of the apophyses for insertion of stylet muscles and the width of the bucco-pharyngeal tube. Finally, we advocate that Diphascon marcusi, a rare species hypothesised to represent either Mesocrista or Adropion, should be transferred to the latter genus and that the species should be redescribed to confirm its validity and systematic position. http://zoobank.org/urn:lsid:zoobank.org:pub:6515D58D-8469-4854-8687-177232112BDA

Selective sweep of Wolbachia and parthenogenetic host genomes – the example of the weevil Eusomus ovulum

Most parthenogenetic weevil species are postulated to have originated via hybridization, but Wolbachia has also been speculated to play a role via the induction of parthenogenesis. Here, we examine the molecular diversity of Wolbachia and parthenogenetic host genomes. The host species studied here, Eusomus ovulum, is known to be exclusively parthenogenetic and triploid. The E. ovulum populations that we examined had a low genetic diversity of mitochondrial (cytochrome oxidase I gene) and nuclear markers (internal transcribed spacer 2 and elongation factor 1‐α gene), and they all were infected by only single bacteria strains (genotyped for five genes according to the multilocus sequence typing system). We found significant signs of linkage disequilibrium and a lack of recombination amongst all of the examined genomes (bacteria and host), which strongly indicates a selective sweep. The lack of heterozygosity in host nuclear genes, missing bisexual populations and selective sweep between the parthenogenetic host and bacteria genomes suggest that parthenogenesis in this species could have originated as a result of infection rather than hybridization. However, the finding that highly similar Wolbachia strains are also present in other parthenogenetic weevils from the same habitat suggests the opposite scenario: bacteria may have infected the already parthenogenetic lineage and taken advantage of the hosts unisexual reproduction.

The Secondary Contact Zone of Phylogenetic Lineages of the Philaenus spumarius (Hemiptera: Aphrophoridae): An Example of Incomplete Allopatric Speciation

Abstract Previous studies on the phylogeography of the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae) suggest the existence of a contact zone of its main phylogenetic lineages along mountain chains in Europe and western Asia. This study presents a detailed examination of the population genetics of P. spumarius within the Carpathian Mountains. The main objective was to determine whether the populations inhabiting that area consist of individuals belonging to different genetic units and whether the observed pattern could be an example of secondary contact zone which formed after incomplete allopatric speciation. Specimens from six transects across the Carpathian arc were examined. The mitochondrial phylogeography of the meadow spittlebug in the examined area clearly shows that individuals from both main clades meet and mix there. Representatives of all three main EF1-α clades were also found. The present distribution of the main clades with a zone of overlap along the mountain ranges may suggest that these phylogenetic lineages form a young hybrid zone. Moreover, a limited number of individuals were shown to possess heteroplasmic mitochondrial DNA, which gives additional support to intraspecific hybridization. P. spumarius could be used in future work as an excellent model species in investigating population genetics, intraspecific hybridization, and speciation in progress.Previous studies on the phylogeography of the meadow spittlebug Philaenus spumarius (L.) (Hemiptera: Aphrophoridae: Cercopidae) suggest the existence of a contact zone of its main phylogenetic lineages along mountain chains in Europe and western Asia. This study presents a detailed examination of the population genetics of P. spumarius within the Carpathian Mountains. The main objective was to determine whether the populations inhabiting that area consist of individuals belonging to different genetic units and whether the observed pattern could be an example of secondary contact zone which formed after incomplete allopatric speciation. Specimens from six transects across the Carpathian arc were examined. The mitochondrial phylogeography of the meadow spittlebug in the examined area clearly shows that individuals from both main clades meet and mix there. Representatives of all three main EF1-α clades were also found. The present distribution of the main clades with a zone of overlap along the mountain ranges may suggest that these phylogenetic lineages form a young hybrid zone. Moreover, a limited number of individuals were shown to possess heteroplasmic mitochondrial DNA, which gives additional support to intraspecific hybridization. P. spumarius could be used in future work as an excellent model species in investigating population genetics, intraspecific hybridization, and speciation in progress.

High Mitochondrial Diversity in a New Water Bear Species (Tardigrada: Eutardigrada) from Mountain Glaciers in Central Asia, with the Erection of a New Genus Cryoconicus

Abstract. Glaciers and ice sheets are considered a biome with unique organism assemblages. Tardigrada (water bears) are micrometazoans that play the function of apex consumers on glaciers. Cryoconite samples with the dark-pigmented tardigrade Cryoconicus gen. nov. kaczmareki sp. nov. were collected from four locations on glaciers in China and Kyrgyzstan. The erection of the new genus is based on a unique combination of morphological traits as well as on phylogenetic analyses. The analysis of COI sequences in the new species revealed high genetic differentiation with 9 haplotypes shared among 13 sequenced individuals from three sequenced populations. There was no apparent geographic structure in COI haplotype diversity, which might indicate effective dispersal abilities of the new species. A recovery of numerous live individuals from a sample that was frozen for 11 years suggests high survival rates in the natural environment. The ability to withstand low temperatures, combined with dark pigmentation that is hypothesised to protect from intense UV radiation, could explain how the new taxon is able to dwell in an extreme glacial habitat. We also found that a rare mountain tardigrade Ramazzottius cataphractus (Maucci, 1974) is morphologically similar to the new species, therefore we propose to transfer it to the new genus. Our study indicates that glacier invertebrate fauna is still poorly known and requires intense research.

Untangling the Echiniscus Gordian knot: Stellariscus gen. nov. (Heterotardigrada : Echiniscidae) from Far East Asia

Abstract. Species constituting the family Echiniscidae are highly derived, armoured and inhabit terrestrial habitats, in contrast to other heterotardigrades that are predominantly marine. The genus Echiniscus C.A.S. Schultze, 1840, nominal for the family Echiniscidae, is currently the most speciose tardigrade genus. However, the great morphological variability, in comparison with other heterotardigrade genera, suggests the polyphyletic character of the genus. Here, we analyse new specimens of Echiniscus pseudelegans Séméria, 1994 collected in Japan and conclude that the species as well as two other related taxa, E. elegans Richters, 1907 and E. latifasciatus Dudichev and Biserov, 2000, represent a new genus, Stellariscus, gen. nov. The new genus is characterised by a mixture of peculiar morphological apomorphies: black eyes, star-like dorsal plate sculpturing, no trunk appendages (only cephalic cirri present), two types of ventral plates, and striking sexual dimorphism in both qualitative and quantitative traits. Morphological phylogeny of the family Echiniscidae suggests a close affinity between Stellariscus, Hypechiniscus Thulin, 1928 and Pseudechiniscus Thulin, 1911. The polyphyletic status of both Echiniscus and Testechiniscus Kristensen, 1987 is also inferred. The taxonomic significance of ventral armature in echiniscid phylogeny and taxonomy is discussed.

The relationships within the Chaitophorinae and Drepanosiphinae (Hemiptera, Aphididae) inferred from molecular-based phylogeny and comprehensive morphological data

The Chaitophorinae is a bionomically diverse Holarctic subfamily of Aphididae. The current classification includes two tribes: the Chaitophorini associated with deciduous trees and shrubs, and Siphini that feed on monocotyledonous plants. We present the first phylogenetic hypothesis for the subfamily, based on molecular and morphological datasets. Molecular analyses were based on the mitochondrial gene cytochrome oxidase subunit I (COI) and the nuclear gene elongation factor-1α (EF-1α). Phylogenetic inferences were obtained individually on each of genes and joined alignments using Bayesian inference (BI) and Maximum likelihood (ML). In phylogenetic trees reconstructed on the basis of nuclear and mitochondrial genes as well as a morphological dataset, the monophyly of Siphini and the genus Chaitophorus was supported. Periphyllus forms independent lineages from Chaitophorus and Siphini. Within this genus two clades comprising European and Asiatic species, respectively, were indicated. Concerning relationships within the subfamily, EF-1α and joined COI and EF-1α genes analysis strongly supports the hypothesis that Chaitophorini do not form a monophyletic clade. Periphyllus is a sister group to a clade containing Chaitophorus and Siphini. The Asiatic unit of Periphyllus also includes Trichaitophorus koyaensis. The analysis of morphological dataset under equally weighted parsimony also supports the view that Chaitophorini is an artificial taxon, as Lambersaphis pruinosae and Pseudopterocomma hughi, both traditionally included in the Chaitophorini, formed independent lineages. COI analyses support consistent groups within the subfamily, but relationships between groups are poorly resolved. These analyses were extended to include the species of closely related and phylogenetically unstudied subfamily Drepanosiphinae, which produced congruent results. Genera Drepanosiphum and Depanaphis are monophyletic and sister. The position of Yamatocallis tokyoensis differs in the molecular and morphological analyses, i.e. it is either an independent lineage (EF-1α, COI, joined COI and EF-1α genes) or is nested inside this unit (morphology). Our data also support separation of Chaitophorinae from Drepanosiphinae.