Батрахологія

Постійне посилання колекціїhttps://ekhnuir.karazin.ua/handle/123456789/752

Переглянути

Результати пошуку

Зараз показуємо 1 - 5 з 5
  • Ескіз
    Документ
    Distinct fate of the asexual genomes in two convergently evolved Pelophylax hybridogenetic systems
    (Sex uncovered: the evolutionary biology of reproductive systems. – Roscoff (Brittany), France., 2018) Mazepa, G.; Doležálková, M.; Choleva, L.; Ploetner, J.; Biriuk, O.; Drohvalenko, M.; Korshunov, O.; Shabanov, D.; Wolf, J.; Perrin, N.
  • Ескіз
    Документ
    Pecularities of oogenesis in hybridogenetic european water frog complex (Pelophylax esculentus com-plex)
    (Bologna: Dipartimento BiGeA Complesso Belmeloro, 2013) Dedukh, D.; Mazepa, G.; Shabanov, D.; Rosanov, J.; Litvinchuk, S.; Saifitdinova, A.; Krasikova, A.
  • Ескіз
    Документ
    Influence of environmental conditions on the distribution of Central Asian green toads with three ploidy levels
    (Journal of Zoological Systematics and Evolutionary Research, 2011) Litvinchuk, S.N.; Mazepa, G.; Pasynkova, R.A.; Saidov, A.; Satorov, T.; Chikin, Yu.; Shabanov, D.A.; Crottini, A.; Borkin, L.J.; Rosanov, J.M.; Stock, M.
    We studied the distribution of Palearctic green toads (Bufo viridis subgroup), an anuran species group with three ploidy levels, inhabiting the Central Asian Amudarya River drainage. Various approaches (one-way, multivariate, components variance analyses and maximum entropy modelling) were used to estimate the effect of altitude, precipitation, temperature and land vegetation covers on the distribution of toads. It is usually assumed that polyploid species occur in regions with harsher climatic conditions (higher latitudes, elevations, etc.), but for the green toads complex, we revealed a more intricate situation. The diploid species (Bufo shaartusiensis and Bufo turanensis) inhabit the arid lowlands (from 44 to 789 m a.s.l.), while tetraploid Bufo pewzowi were recorded in mountainous regions (340–3492 m a.s.l.) with usually lower temperatures and higher precipitation rates than in the region inhabited by diploid species. The triploid species Bufo baturae was found in the Pamirs (Tajikistan) at the highest altitudes (2503–3859 m a.s.l.) under the harshest climatic conditions.
  • Ескіз
    Документ
    Optional endoreplication and selective elimination of parental genomes during oogenesis in diploid and triploid hybrid european water frogs
    (PLoS ONE, 2015) Dedukh, D.; Litvinchuk, S.; Rosanov, Ju.; Mazepa, G.; Saifitdinova, A.; Shabanov, D.; Krasikova, A.
    Incompatibilities between parental genomes decrease viability of interspecific hybrids; however, deviations from canonical gametogenesis such as genome endoreplication and elimination can rescue hybrid organisms. To evaluate frequency and regularity of genome elimination and endoreplication during gametogenesis in hybrid animals with different ploidy, we examined genome composition in oocytes of di- and triploid hybrid frogs of the Pelophylax esculentus complex. Obtained results allowed us to suggest that during oogenesis the endoreplication involves all genomes occurring before the selective genome elimination. We accepted the hypothesis that only elimination of one copied genome occurs premeiotically in most of triploid hybrid females. At the same time, we rejected the hypothesis stating that the genome of parental species hybrid frogs co-exist with is always eliminated during oogenesis in diploid hybrids. Diploid hybrid frogs demonstrate an enlarged frequency of deviations in oogenesis comparatively to triploid hybrids. Typical for hybrid frogs deviations in gametogenesis increase variability of produced gametes and provide a mechanism for appearance of different forms of hybrids.
  • Ескіз
    Документ
    Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine
    (BMC Genetics, 2013) Dedukh, D.; Mazepa, G.; Shabanov, D.; Rosanov, Ju.; Litvinchuk, S.; Borkin, L.; Saifitdinova, A.; Krasikova, A.
    Hybridogenesis (hemiclonal inheritance) is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species. European water frogs (Pelophylax esculentus complex) represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance and polyploidization. P. esculentus complex consists of two parental species, P. ridibundus (the lake frog) and P. lessonae (the pool frog), and their hybridogenetic hybrid – P. esculentus (the edible frog). Parental and hybrid frogs can reproduce syntopically and form hemiclonal population systems. For studying mechanisms underlying the maintenance of water frog population systems it is required to characterize the karyotypes transmitted in gametes of parental and different hybrid animals of both sexes. In order to obtain an instrument for characterization of oocyte karyotypes in hybrid female frogs, we constructed cytological maps of lampbrush chromosomes from oocytes of both parental species originating in Eastern Ukraine. We further identified certain molecular components of chromosomal marker structures and mapped coilin-rich spheres and granules, chromosome associated nucleoli and special loops accumulating splicing factors. We recorded the dissimilarities between P. ridibundus and P. lessonae lampbrush chromosomes in the length of orthologous chromosomes, number and location of marker structures and interstitial (TTAGGG) n–repeat sites as well as activity of nucleolus organizer. Satellite repeat RrS1 was mapped in centromere regions of lampbrush chromosomes of the both species. Additionally, we discovered transcripts of RrS1 repeat in oocytes of P. ridibundus and P. lessonae. Moreover, G-rich transcripts of telomere repeat were revealed in association with terminal regions of P. ridibundus and P. lessonae lampbrush chromosomes.