Karyotypes of european species of radix (Gastropoda: Pulmonata: Lymnaeidae) and their relevance to species distinction in the genus

Karyotypes of Radix auricularia (Linnaeus, 1758) and three disputable taxa considered by different authors as distinct species or assigned as forms of Radix peregra (Muller, 1774), sensu lato - R. labiata (Rossmassler, 1835), R. balthica (Linnaeus, 1758), and R. ampla (Hartmann, 1821) - were studied with preparations obtained from gonad tissues by the airdrying method. The studied taxa have the same diploid number (2n = 34), but are characterized by different morphology of some chromosome pairs. In particular, R. labiata (traditionally identified as R. peregra, s. s.) and R. balthica (= R. ovata in traditional understanding) differ in the number of subtelocentric chromosomes (1 and 5, respectively), species status of these taxa being also supported by pronounced differences in centomeric indexes of chromosome pairs 4 and 16. Species distinctness of R. ampla is supported by differences in three chromosome pairs, and karyological similarity between this taxon and R. balthica is also noted. FN values varied among the studied taxa from 56 in R. ampla to 66 in R. labiata. The known karyological characters are traced on phylogenetic trees suggested by recent molecular reconstructions. This study demonstrates that karyology can be an effective tool for aiding taxonomic distinctions of historically problematic groups of molluscs

Karyotypes of two European species of the genus Lymnaea with disputable taxonomic status (Gastropoda: Pulmonata: Lymnaeidae)

Karyotypes of Lymnaea corvus and L. occulta are studied for the first time and compared to the original data on Ukrainian populations of L. palustris and L. stagnalis. While all the studied species have the same diploid chromosome number (2n = 36), they differ in chromosome morphology. Karyotypes of L. occulta and L. palustris include only biarmed chromosomes (number of arms = 72). In contrast, L. corvus and L. stagnalis have also uniarmed (acrocentric) chromosomes (number of arms = 60 and 62, respectively). Karyological data confirm specific distinctness of L. occulta and L. corvus; however, similarity in the chromosome morphology of the latter species to L. stagnalis is probably based on symplesiomorphies and, thus, cannot support phylogenetic relationship suggested earlier on the basis of anatomical characters. Kurzfassung. Karyotypen von zwei europдischen Arten der Gattung Lymnaea mit umstrittenem taxonomischen Status (Gastropoda: Pulmonata: Lymnaeidae). - Karyotypen von Lymnaea corvus und L. occulta wurden erstmalig untersucht und mit den originalen Daten fьr ukrainische Populationen von L. stagnalis und L. palustris verglichen. Alle untersuchten vier Arten weisen dieselbe Anzahl diploider Chromosomen auf (2n = 36), kцnnen aber durch die Morphologie der Chromosomen unterschieden werden. Die Karyotypen von L. occulta enthalten nur zweiarmige Chromosomen (Anzahl der Arme = 72). Im Gegensatz hierzu weisen L. corvus und L. stagnalis auch einarmige (akrozentrische) Chromosomen auf (Anzahl der Arme = 60 beziehungsweise 62). Die karyologischen Befunde bestдtigen die spezifische Verschiedenheit von L. occulta und L. corvus; jedoch ist die Дhnlichkeit in der Chromosomenmorphologie der letzteren Art gegenьber L. stagnalis wahrscheinlich auf Symplesiomorphien zurьckzufьhren, deshalb kann die frьher auf der Basis anatomischer Merkmale behauptete phylogenetische Verwandtschaft von L. corvus und L. stagnalis nicht unterstьtzt werden

Karyological Features of the Genus Planorbarius (Gastropoda, Pulmonata, Bulinidae) of the Ukranian Fauna

The absence of significant distinctions between the species of the genus Planorbarius in the narrow sense (P. corneus, P. banaticus, P. purpura, and P. grandis) has been established. All investigated species had identical chromosomal formulas (2n= 30 m + 6 sm = 36) and fundamental numbers (FN = 72). Reproducible distinctions between them were not found by total complement length (TCL), relative length of chromosomes (RL), and centromeric indexes. The species selected on the basis of genetic marking differed clearly by centromeric index of chromosome 12, which confirms the allospecies frame of P.corneus s. lato

Stochastic differential equations for limiting description of UCB rule for Gaussian multi-armed bandits

We consider the upper confidence bound strategy for Gaussian multi-armed bandits with known control horizon sizes $N$ and build its limiting description with a system of stochastic differential equations and ordinary differential equations. Rewards for the arms are assumed to have unknown expected values and known variances. A set of Monte-Carlo simulations was performed for the case of close distributions of rewards, when mean rewards differ by the magnitude of order $N^{-1/2}$, as it yields the highest normalized regret, to verify the validity of the obtained description. The minimal size of the control horizon when the normalized regret is not noticeably larger than maximum possible was estimated.Comment: 9 pages, 2 figure

Features of the Genetic Structure of the Earthworms Aporrectodea (Superspecies) Caliginosa (Oligochaeta: Lumbricidae) Complex in Ukraine

An investigation of the genetic structure of the Aporrectodea caliginosa – A. trapezoids diploidpolyploid complex of earthworms found in the Ukraine is performed by means of biochemical genetic marking with respect to six loci (Aat, Es-1, -2, -3, and -4, and Mdh) and karyotyping. All 646 individuals from 21 samples are analyzed at the biochemical gene level and karyotype samples are obtained from 70 specimens. As a result, diploid amphimictic A. caliginosa individuals (2n = 36), which form panmictic populations, and triploid (2n = 54) A. trapezoides individuals, represented by 19 hypothetical clones discovered in the course of an analysis of 157 specimens, are clearly differentiated. A clear trend towards dominance of the triploid forms in the steppe zone of Ukraine is discovered. Here they represent roughly 70% as against 12% of all A. (superspecies) caliginosa individuals in the northern forest regions. Based on the stated nature of the heterozygosity of the loci studied and the behavior of the chromosomes in meiosis, it may be claimed that the cloned forms are allotriploids, formed as a result of hybridization of a series of related forms, which, judging from the allelic pools, does not include amphimictic species that now inhabit the territory of Ukraine. That is, either the apomictic clones of A. trapezoides lack a local origin and their appearance among the fauna of Ukraine is a consequence of settlement in arid steppe regions that are unfavorable for earthworms or, on the other hand, amphimictic A. caliginosa is an invasive species

Polyploid races, genetic structure and morphological features of the earthworm Octodrіlus transpadanus (Rosa, 1884) (Oligohaeta: Lumbricidae) in the Ukraine

Kariological investigation of the earthworm Octodrilus transpada-nus (Rosa, 1884) in the Ukraine showed that this species is represented by at least three races of different ploidy with the basic chromosome number n=15. Strict geographic heterogeneity of electrophoretic spectra of different populations was registered: south-eastern populations (7n=105) are characterized by a clonal structure, whereas western (from 3n = 45 to 4n = 60) and south-western (2n=30) ones have a high level of polymorphism. The Crimea sample (4n=60) is well isolated, has no clonal structure and is characterized by a series of specifi c alleles , which are absent in forms from continental Ukraine. All the forms turned out to be wel

Polyploid races, genetic structure and morphological features of earthworm Aporrectodea rosea (Savigny, 1826) (Oligohaeta: Lumbricidae) in Ukraine

Four chromosomal races (2n=36, 3n=54, 6n=108, 8n=144) and 96 clones have been revealed among 224 specimens of the earthworm A. rosea over the territory of Ukraine by means of karyological analysis and biochemical genetic marking. Each population has been showed by several clones at least; moreover the clones from different places have never been identical. The clones in the range of one population can be identified with the set of quantitative and qualitative parameters

On Sexual Dimorphism of Karyotypes of Viviparus Viviparus and V. Contectus (Gastropoda, Viviparidae)

On Sexual Dimorphism of Karyotypes of Viviparus viviparus and V. contectus (Gastropoda, Viviparidae). Andriichuk, T. V., Garbar, A. V. — Karyotype analysis of males and females of two Viviparid species Viviparus viviparus Linnaeus, 1758 and V. contectus (Millet, 1813), shows diff erences in their karyotypes in the absence of heteromorphic pairs of chromosomes. Th is indicates an epigamous mechanism of sex determination

Efficiency of an inexpensive liquid-based cytology performed by cytocentrifugations: a comparative study using the histology as reference standard

BACKGROUND: Although liquid-based cytology (LBC) is now recommended for cervical cancer screening, it requires expensive automated devices and materials. To evaluate the efficiency of inexpensive LBC methods relying on an inexpensive fixative liquid, Easyfix(®), we compared the results obtained by the liquid-based cytology (LBC) diagnoses performed by cytocentrifugations (Papspin(® )and Turbitec(®)) with those obtained by histology. Furthermore, we evaluated the efficiency of the fixative liquid, Easyfix(®), to preserve HPV DNA in the collected samples. METHOD: 266 LBC were compared with 174 colposcopies and 91 Loop Electrosurgical Excision Procedure (LEEP). Among the LBC, 51 were performed using the Papspin(® )system and 215 were performed using the Turbitec(® )system. To control the quality of the preservation liquid, Easyfix(®), we correlated the results of HCII assays with those of HPV PCR. RESULTS: For Papspin(® )and Turbitec(® )systems, the sensitivities were respectively 82.6% (95% CI: 61.2–95.0%, p < 0.001) and 75.0% (95% CI: 64.4–89.8%, p < 0.001) and the specificities were 92.6% (95%CI: 76.5–99.1%, p < 0.001) and 96.2% (95% CI: 91.3–98.7%, p < 0.001). We find no statistical difference between the results of the both systems (p = ns). The sensitivity of the HCII was 86.4% (95% IC: 77.4–92.8%, p < 0.001) and the specificity was 39.4% (95% CI: 31.2–48.1%, p < 0.001). The comparison between HCII and HPV-PCR shows a good correlation: the kappa was 0.89. CONCLUSION: LBC performed by cytocentrifugations are inexpensive, reduce inadequate smears, show excellent efficiency and allow HPV detection by molecular biology