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Skorinov D. ., Rakitskaya T. ., Askenderov A. D., Mazanaeva L. ., Litvinchuk S. N. Hybridization and distribution of cryptic species of green toads (Bufotes) (Bufonidae, Amphibia) in Republic of Dagestan (Russia). Current Studies in Herpetology, 2024, vol. 24, iss. 1, pp. 20-29. DOI: https://doi.org/10.18500/1814-6090-2024-24-1-2-20-29
Hybridization and distribution of cryptic species of green toads (Bufotes) (Bufonidae, Amphibia) in Republic of Dagestan (Russia)
Distribution of cryptic species of green toads (Bufotes viridis and B. sitibundus) in Dagestan still understudied. We used the nuclear (microsatellite BM224) and mitochondrial (fragment of the CytB gene) markers characterized by species-specific alleles and haplotypes, respectively. Alleles of B. viridis predominated in toad populations in the plains in the north of the republic, while B. sitibundus alleles were more numerous in more southern mountainous and coastal (the coast of the Caspian Sea southeast of Makhachkala) regions. Most samples contained both homozygous and heterozygous genotypes. The distribution of haplotypes for the CytB gene in the republic differed markedly from that for the BM224 microsatellite. If we compare the occurrence of BM224 alleles and CytB haplotypes in studied populations, the relationship between them turned out to be very weak. In many individuals, the nuclear marker belonged to one species, while the mitochondrial marker belonged to another species, indicating the widespread asymmetric introgression of mitochondrial genomes here. We found a significant correlation between the altitude of location and the occurrence of BM224 alleles. In mountainous regions of the republic, populations of B. sitibundus were predominantly distributed, while in lowland regions hybrid populations were revealed, in which the predominance of B. viridis alleles was typical for the most northern populations inhabiting dry steppe and semi-desert landscapes.
Askenderov A. D. Amphibians of Dagestan: Distribution, Ecology, Conservation. Diss. Cand. Sci. (Biol.). Togliatti, 2017. 223 p. (in Russian).
Bannikov A. G., Darevsky I. S., Ishchenko V. G., Rustamov A. K., Shcherbak N. N. Opredelitel' zemnovodnykh i presmykayushchikhsya fauny SSSR [A Guide of Amphibians and Reptiles of Fauna of USSR]. Moscow, Prosveshchenie, 1977. 415 p. (in Russian).
Borkin L. J., Litvinchuk S. N. Animal Hybridization, Speciation and Systematics. Proceedings of the Zoological Institute RAS, 2013, vol. 317, suppl. 2, pp. 83–139 (in Russian).
Borkin L. J., Litvinchuk S. N., Rosanov J. M., Skorinov D. V. On cryptic species (from the example of amphibians). Zoologicheskii zhurnal, 2004, vol. 83, iss. 8, pp. 936–960 (in Russian).
Kuzmin S. L. Amphibians of the Former USSR. Moscow, KMK Scientific Press Ltd, 2012. 370 p. (in Russian).
Litvinchuk S. N., Rosanov Yu. M., Usmanova N. M., Borkin L. Ja., Mazanaeva L. F., Kazakov V. I. Variation of microsatellites BM224 and BCAL7 in populations of green toads (Bufo viridis complex) with various nuclear DNA content and ploidy. Tsitologiya, 2006, vol. 48, iss. 4, pp. 306–319 (in Russian).
Litvinchuk S. N., Rosanov J. M., Borkin L. J., Skorinov D. V. Molecular, biochemical and cytogenetic aspects of microevolution in anurans of Russia and adjacent countries. Proceedings of the 3th Meeting of the Nikolsky Herpetological Society “The Problems of Herpetology”. Saint Petersburg, Zoological Institute of the Russian Academy of Sciences Publ., 2008, pp. 247–257 (in Russian).
Faizulin A. I., Svinin A. O., Ruchin A. B., Skorinov D. V., Borkin L. J., Rosanov Yu. M., Kuzovenko A. E., Litvichuk S. N. Distribution and contact zone of two forms of the green toad from the Bufotes viridis complex (Anura, Amphibia), differing in genome size, in the Volga Region. Current Studies in Herpetology, 2018, vol. 18, iss. 1–2, pp. 35–45 (in Russian). https://doi.org/10.18500/ 1814-6090-2018-18-1-2-35-45
Formozow N. A. Introgression of alien mitotypes as a consequence of Godfrey Hewitt's leading edge hypo-thesis: Influence of male or female heterogamety and sex ratio in dispersing populations. In: Modern Problems of Biological Evolution: Conference materials for the 100th anniversary of the State Darwin Museum. Moscow, State Darwin Museum Publ., 2007. pp. 155–157 (in Russian).
Borkin L. J., Rosanov J. M., Litvinchuk S. N. Nuclear DNA content in some green toads (Bufo viridis complex) of Turkey and Iran. Russian Journal of Herpetology, 2000, vol. 8, no. 3, pp. 171–180.
Dufresnes C., Litvinchuk S. N. Diversity, distribution and molecular species delimitation in frogs and toads from the Eastern Palaearctic. Zoological Journal of the Linnean Society, 2022, vol. 195, iss. 3, pp. 695–760. https://doi.org/10.1093/zoolinnean/zlab083
Dufresnes C., Mazepa G., Jablonski D., Olivei-ra R. C., Wenseleers T., Shabanov D. A., Auer M., Ernst R., Koch C., Ramírez-Chaves H. E., Mulder K. P., Simonov E., Tiutenko A., Kryvokhyzha D., Wennekes P. L., Zinenko O. I., Korshunov O. V., Al-Johany A. M., Peregontsev E.A., Masroor R., Betto-Colliard C., Denoël M., Borkin L. J., Skorinov D. V., Pasynkova R. A., Mazanaeva L. F., Rosanov J. M., Dubey S., Litvinchuk S. Fifteen shades of green: The evolution of Bufotes toads revisited. Molecular Phylogenetics and Evolution, 2019, vol. 141, article no. 106615. https://doi.org/10.1016/j.ympev.2019. 106615
Dufresnes C., Brelsford A., Jeffries D. L., Mazepa G., Suchan T., Canestrelli D., Nicieza A., Fumagalli L., Dubey S., Martínez-Solano I., Litvinchuk S. N., Vences M., Perrin N., Crochet P.-A. Mass of genes rather than master genes underlie the genomic architecture of amphibian speciation. Proceedings of the National Academy of Sciences USA, 2021a, vol. 118, no. 36, article no. e2103963118. https://doi.org/10.1073/ pnas.2103963118.
Dufresnes C., Probonas N. M., Strachinis I. A reassessment of the diversity of green toads (Bufotes) in the circum-Aegean region. Integrative Zoology, 2021b, vol. 16, iss. 3, pp. 420–428. https://doi.org/10.1111/1749-4877.12494
Frost D. R. Amphibian Species of the World: An Online Reference. Version 6.2. New York, American Museum of Natural History, 2023. Available at: http:// research.amnh.org/herpetology/amphibia/index.html (accessed 30 June, 2023).
Höglund J., Bolender L., Cortazar‑Chinarro M., Meurling S., Laurila A., Hermaniuk A., Dufresnes C. Low neutral and immunogenetic diversity in northern fringe populations of the green toad Bufotes viridis: Implications for conservation. Conservation Genetics, 2022, vol. 23, iss. 1, pp. 139–149. https://doi.org/10.1007/ s10592-021-01407-5
Speybroeck J., Beukema W., Dufresnes C., Fritz U., Jablonski D., Lymberakis P., Martínez-Solano Í., Razzetti E., Vamberger M., Vences M., Vörös J., Crochet P.-A. Species list of the European herpetofauna – 2020 update by the Taxonomic Committee of the Societas Europaea Herpetologica. Amphibia – Reptilia, 2020, vol. 41, iss. 2, pp. 139–189. https://doi.org/10.1163/15685381-bja10010
Stöck M., Moritz C., Hickerson M., Frynta D., Dujsbayeva T., Eremchenko V., Macey J. R., Papen-fuss T. J., Wake D. B. Evolution of mitochondrial relationships and biogeography of Palearctic green toads (Bufo viridis subgroup) with insights in their genome plasticity. Molecular Phylogenetics and Evolution, 2006, vol. 41, iss. 3, pp. 663–689. https://doi.org/10.1016/ j.ympev.2006.05.026
Stöck M., Roth P., Podloucky R., Grossenbacher K. Wechselkröten – unter Berücksichtigung von Bufo viridis virdis Laurenti, 1768; Bufo variabilis Pallas, 1769; Bufo boulengeri Lataste, 1879; Bufo balearicus Böttger, 1880 und Bufo siculus Stöck, Sicilia, Belfiore, Lo Brutto, Lo Valvo und Arculeo, 2008. In: Handbuch der Amphibien und Reptilien Europas. Froschlurche II. Bd. 5. Wiesbaden, AULA-Verlag, 2008, S. 413–498.
Tikel D., Paetkau D., Cortinas M. N., Leblois R., Moritz C., Estoup A. Polymerase chain reaction primers for polymorphic microsatellite loci in the invasive toad species Bufo marinus. Molecular Ecology, 2000, vol. 9, iss. 11, pp. 1927–1929. https://doi.org/10.1046/ j.1365-294x.2000.01074-6.x
