Distribution of Bufotes latastii (Boulenger, 1882), endemic to the Western Himalaya.

The distribution of Bufotes latastii, a diploid green toad species, is analyzed based on field observations and literature data. 74 localities are known, although 7 ones should be confirmed. The range of B. latastii is confined to northern Pakistan, Kashmir Valley and western Ladakh in India. All records of “green toads” (“Bufo viridis”) beyond this region belong to other species, both to green toads of the genus Bufotes or to toads of the genus Duttaphrynus. B. latastii is endemic to the Western Himalaya. Its allopatric range lies between those of bisexual triploid green toads in the west and in the east. B. latastii was found at altitudes from 780 to 3200 m above sea level. Environmental niche modelling was applied to predict the potential distribution range of the species. Altitude was the variable with the highest percent contribution for the explanation of the species distribution (36 %)

Розширення функціональних можливостей РНР для перевірки отриманих від користувача даних

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

Genomic Evidence for Cryptic Speciation in Tree Frogs From the Apennine Peninsula, With Description of Hyla perrini sp. nov

Despite increasing appreciation of the speciation continuum, delimiting and describing new species is a major yet necessary challenge of modern phylogeography to help optimize conservation efforts. In amphibians, the lack of phenotypic differences between closely-related taxa, their complex, sometimes unresolved phylogenetic relationships, and their potential to hybridize all act to blur taxonomic boundaries. Here we implement a multi-disciplinary approach to evaluate the nature of two deeply-diverged mitochondrial lineages previously documented in Italian tree frogs (Hyla intermedia s. l.), distributed north and south of the Northern Apennine Mountains. Based on evidence from mitochondrial phylogenetics, nuclear phylogenomics, hybrid zone population genomics, niche modeling analyses, and biometric assessments, we propose that these lineages be considered distinct, cryptic species. Both mitochondrial and nuclear data affirm that they belong to two monophyletic clades of Pliocene divergence (~3.5 My), only admixing over a relatively narrow contact zone restricted to the southeast of the Po Plain (50–100 km). These characteristics are comparable to similarly-studied parapatric amphibians bearing a specific status. Inferred from their current geographic distribution, the two Italian tree frogs feature distinct ecological niches (<15% of niche overlap), raising questions regarding potential adaptive components contributing to their incipient speciation. However, we found no diagnostic morphological and bioacoustic differences between them. This system illustrates the speciation continuum of Western-Palearctic tree frogs and identifies additional cryptic lineages of similar divergence to be treated as separate species (H. cf. meridionalis). We recommend combined approaches using genomic data as applied here for the future taxonomic assessment of cryptic diversity in alloparapatric radiations of terrestrial vertebrates, especially in controversial taxa. Finally, we formally described the northern Italian tree frogs as a new species, Hyla perrini sp. nov

The genus Pelophylax (Amphibia, Ranidae) in Pakistan: museum collections and possible distribution

We provide the first comprehensive data on the questionable distribution of the genus Pelophylax and the family Ranidae from Pakistan. Based on a literature review and two specimens of the genus from Tasp, Panjgur District in Pakistani Balochistan (USNM 26194–95), stored in the Smithsonian National Museum of Natural History, Washington, DC, USA, we discuss the possible occurrence and affiliation of these frogs in the context of Central Asia. Our comparison shows that the nearest records of Pelophylax in relation to the Tasp specimens are reported from more than 280 km (air-line) away in Iran and Afghanistan, which are currently separated by hot and mostly desert environments. We suggest that possible surviving populations of this genus may still be present in Balochistan (Rakhshan River) or Khyber Pakhtunkhwa (Kabul River) Provinces of Pakistan. This would, however, need further field investigations

Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine

Background: 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. Results: 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. Conclusions: The constructed cytological maps of lampbrush chromosomes of P. ridibundus and P. lessonae provide basis to define the type of genome transmitted within individual oocytes of P. esculentus females with different ploidy and from various population systems

Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine

Background: 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. Results: 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. Conclusions: The constructed cytological maps of lampbrush chromosomes of P. ridibundus and P. lessonae provide basis to define the type of genome transmitted within individual oocytes of P. esculentus females with different ploidy and from various population systems

Interstitial (TTAGGG)_n repeat sites mapping allows to identify parental chromosomes in oocytes of hybrid frogs.

<p>(a-c) FISH mapping of (TTAGGG)_n repeat on metaphase chromosomes of <i>P</i>. <i>lessonae</i> (a, a`), <i>P</i>. <i>ridibundus</i> (b), and diploid <i>P</i>. <i>esculentus</i> (c). One or two interstitial (TTAGGG)<sub>n</sub> repeat sites distinguish parental NOR-bearing chromosomes H (arrows). Asterisks indicate enlarged fragment with two NOR-bearing chromosomes of <i>P</i>. <i>lessonae</i>. Arrows indicate interstitial (TTAGGG)<sub>n</sub> repeat sites. (d1–f1`) Lampbrush chromosomes from oocytes of triploid hybrid frogs with RRL (d1–d6`) and LLR (e1–f1`) genotypes. FISH mapping of (TTAGGG)_n repeat revealed lampbrush chromosome H corresponding to <i>P</i>. <i>ridibundus</i> (d6) or <i>P</i>. <i>lessonae</i> (e1) LBC H. Interstitial (TTAGGG)_n repeat sites are shown by square brackets. Lampbrush chromosomes corresponding to <i>P</i>. <i>ridibundus</i> LBC F (d1,d1`), G (d2,d2`), D (d3,d3`), I (d4,d4`), B (d5,d5`), and <i>P</i>. <i>lessonae</i> LBC B (e2,b2`), F (e3,b3`), L (f1,f1`) are shown. Chromosomes on micrographs (d1–d6`) were taken from the full lampbrush chromosome set represented on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123304#pone.0123304.g001" target="_blank">Fig 1a,a`</a>. Chromosomes on micrographs (e1–e3`) were taken from the from the full lampbrush chromosome set represented on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123304#pone.0123304.g001" target="_blank">Fig 1c,c`</a>. Various marker structures are shown by arrows. Chromosomes were counterstained with DAPI. Corresponding phase-contrast micrographs are shown (d1`,d2`,d3`,d4`,d5`,d6`,e1`,e2`,e3`,f1`). Arrowheads indicate centromeres. Scale bars = 10 μm for all panels except a`, where scale bar = 2 μm.</p

Suggested additional mechanisms of oogenesis in two triploid frogs with RRL genotype and one diploid hybrid frog.

<p>(a) During oogenesis of one triploid frog with RRL genotype neither elimination nor endoreplication occurred to form oocytes with 39 univalents (at the top), endoreplication of all genomes took place to form oocytes with 39 bivalents (in the middle), individual chromosomes from L genome (blue) were lost to form oocytes with aneuploid chromosomal sets (at the bottom). (b) During oogenesis of another triploid frog with RRL genotype elimination of L genome (blue) occurred to form oocytes with 13 bivalents (at the top), premeiotic elimination and endoreplication were absent to form oocytes with 39 univalents (in the middle), endoreplication of all genomes took place to form oocytes with 39 bivalents (at the bottom). (c) During oogenesis of one diploid hybrid frog L genome (blue) was eliminated in all observed oocytes. One round of R genome (orange) endoreplication occurred but bivalents formation was incomplete to form oocytes with both univalents and bivalents (at the top). Two rounds of endoreplication of R genome took place to form oocytes 26 bivalents (in the middle). One round of R genome endoreplication occurred but bivalents could not form that led to formation of oocytes with 26 univalents (at the bottom).</p