{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,8]],"date-time":"2025-12-08T10:49:43Z","timestamp":1765190983254,"version":"3.46.0"},"reference-count":57,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,12,8]],"date-time":"2025-12-08T00:00:00Z","timestamp":1765152000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genes"],"abstract":"<jats:p>Madagascar is one of the world\u2019s most prominent biodiversity hotspots and is characterized by exceptionally high amphibian diversity, with 429 currently described, mostly endemic species. However, cytogenetic research on Malagasy amphibians has been conducted only intermittently over the years. Previous studies, mostly using conventional staining and banding methods and often confined to single taxa or isolated families, have provided only partial insights into the karyotype evolution and genome organization of the major Malagasy clades. In this contribution, we present the first comprehensive synthesis of all available cytogenetic data on Malagasy anurans, including chromosome number and morphology, heterochromatin distribution, and chromosomal markers across the major endemic Malagasy families. By integrating and comparing results from decades of scattered studies, this review reveals consistent patterns of chromosomal diversification and identifies evolutionary trends associated with speciation and adaptive radiation in Malagasy amphibians. Overall, native Malagasy amphibian species can be subdivided into two main karyotype groups: the first includes karyotypes with only biarmed chromosomes (Heterixalus, Ptychadena, Boophis, Mantella, and Guibemantis), while the second comprises karyotypes with one or more uniarmed elements (Gephyromantis, Mantidactylus, and Microhylidae). The localization of NORs follows a diverse pattern, often varying even among closely related species. Heterochromatin distribution and composition also appear to be species-specific and thus taxonomically informative. Beyond summarizing existing knowledge, this work establishes a unified framework for interpreting chromosome evolution within the unique biogeography and evolutionary history of Madagascar. Our synthesis provides essential baseline data for future molecular, genomic, and conservation studies, thereby enhancing our understanding of the mechanisms that have generated and maintained the island\u2019s extraordinary amphibian diversity.<\/jats:p>","DOI":"10.3390\/genes16121464","type":"journal-article","created":{"date-parts":[[2025,12,8]],"date-time":"2025-12-08T10:35:51Z","timestamp":1765190151000},"page":"1464","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Chromosome Data and Karyotype Diversity of Anurans from Madagascar: Half a Century After the First Broad Cytosystematic Approach"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7246-9831","authenticated-orcid":false,"given":"Marcello","family":"Mezzasalma","sequence":"first","affiliation":[{"name":"Department of Biology, Ecology and Earth Science, University of Calabria, Via P. Bucci 4\/B, 87036 Rende, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1579-7126","authenticated-orcid":false,"given":"Gaetano","family":"Odierna","sequence":"additional","affiliation":[{"name":"Department of Biology, University of Naples Federico II, Via Cinthia 26, 80126 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3669-1395","authenticated-orcid":false,"given":"Elvira","family":"Brunelli","sequence":"additional","affiliation":[{"name":"Department of Biology, Ecology and Earth Science, University of Calabria, Via P. Bucci 4\/B, 87036 Rende, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1511-7792","authenticated-orcid":false,"given":"Fabio M.","family":"Guarino","sequence":"additional","affiliation":[{"name":"Department of Biology, University of Naples Federico II, Via Cinthia 26, 80126 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/BF02240252","article-title":"Threatened biotas: \u201cHot spots\u201d in tropical forests","volume":"8","author":"Myers","year":"1988","journal-title":"Environmentalist"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"853","DOI":"10.1038\/35002501","article-title":"Biodiversity hotspots for conservation priorities","volume":"403","author":"Myers","year":"2000","journal-title":"Nature"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Zachos, F., and Habel, J. (2011). The Kingdom of the Frogs: Anuran Radiations in Madagascar. Biodiversity Hotspots, Springer.","DOI":"10.1007\/978-3-642-20992-5"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1080\/11250000109356414","article-title":"Patterns of amphibian and reptile diversity at Berara Forest (Sahamalaza Peninsula), NW Madagascar","volume":"68","author":"Andreone","year":"2001","journal-title":"Ital. J. Zool."},{"key":"ref_5","unstructured":"IUCN 2025 (2025, September 09). The IUCN Red List of Threatened Species. Version 2025-2, Available online: https:\/\/www.iucnredlist.org."},{"key":"ref_6","unstructured":"(2025, September 09). AmphibiaWeb. 2025. University of California, Berkeley, CA, USA. Available online: https:\/\/amphibiaweb.org."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1163\/15685381-00003104","article-title":"Tracing a toad invasion: Lack of mitochondrial DNA variation, haplotype origins, and potential distribution of introduced Duttaphrynus melanostictus in Madagascar","volume":"38","author":"Vences","year":"2017","journal-title":"Amphibia-Reptilia"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Guarino, F.M., Andreone, F., Mezzasalma, M., Licata, F., Puoti, S., Santos, B., Cocca, W., Solofoniaina Fidy, J.F., Ndriantsoa, S.H., and Noel, J. (2023). Life History Traits and Longevity of the Invasive Asian Common Toad Duttaphrynus melanostictus (Schneider, 1799) in Madagascar. Animals, 13.","DOI":"10.3390\/ani13132099"},{"key":"ref_9","first-page":"1","article-title":"Amphibiens (premie\u2019re partie)","volume":"75","author":"Blanc","year":"1991","journal-title":"Faune Madag."},{"key":"ref_10","unstructured":"Heatwole, H.H., and Tyler, M. (2007). Speciation, species boundaries and phylogeography of amphibians. Amphibian Biology, Surrey Beatty and Sons."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"133","DOI":"10.3897\/zookeys.951.51129","article-title":"Resolving a taxonomic and nomenclatural puzzle in mantellid frogs: Synonymization of Gephyromantis azzurrae with G. corvus, and description of Gephyromantis kintana sp. nov. from the Isalo Massif, western Madagascar","volume":"951","author":"Cocca","year":"2020","journal-title":"ZooKeys"},{"key":"ref_12","first-page":"3","article-title":"A review of the genus Mantella (Anura, Ranidae, Mantellinae): Taxonomy, distribution and conservation of Malagasy poison frogs","volume":"17","author":"Vences","year":"1999","journal-title":"Alytes"},{"key":"ref_13","unstructured":"Louren\u00e7o, W.R., and Goodman, S.M. (2000). Current counts of species diversity and endemism of Malagasy amphibians and reptiles. Diversit\u00e9 et End\u00e9misme a Madagascar, M\u00e9moires de la Soci\u00e9t\u00e9 de Biog\u00e9ographie."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1016\/S0169-5347(01)02187-5","article-title":"Chromosomal rearrangements and speciation","volume":"16","author":"Rieseberg","year":"2001","journal-title":"Trends Ecol. Evol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.jcz.2017.04.006","article-title":"When can chromosomes drive speciation? The peculiar case of the Malagasy tomato frogs (genus Dyscophus)","volume":"268","author":"Mezzasalma","year":"2017","journal-title":"Zool. Anz."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3897\/compcytogen.v16.i1.76260","article-title":"Comparative cytogenetics on eight Malagasy Mantellinae (Anura, Mantellidae) and a synthesis of the karyological data on the subfamily","volume":"16","author":"Mezzasalma","year":"2022","journal-title":"Comp. Cytogenet."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Mezzasalma, M., Brunelli, E., Odierna, G., and Guarino, F.M. (2023). Evolutionary and Genomic Diversity of True Polyploidy in Tetrapods. Animals, 13.","DOI":"10.3390\/ani13061033"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1080\/00087114.1967.10796248","article-title":"Le relazioni tra il cariotipo di anuri diplasioceli","volume":"20","author":"Morescalchi","year":"1967","journal-title":"Caryologia"},{"key":"ref_19","first-page":"261","article-title":"Karyotype de Anodonthyla montana Angel (Anura, Microhylidae) du massif de l\u2019Andringitra (Madagascar)","volume":"10","author":"Blommers","year":"1971","journal-title":"Terre Malg."},{"key":"ref_20","first-page":"21","article-title":"Existence d\u2019une variability chromosomique intrasp6cifique chez Pseudohemisus madagascariensis Blgr. (Batraciens, Ranid6s)","volume":"97","author":"Blommers","year":"1972","journal-title":"Bull. Soc. Zool. Ft."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/BF00121036","article-title":"Chromosomal analysis of twelve species of Microhylidae (Anura) from Madagascar","volume":"46","year":"1976","journal-title":"Genetica"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1007\/BF00125283","article-title":"Cytotaxonomy of the Ranidae, Rhacophoridae, Hyperoliidae (Anura) from Madagascar with a note on the Karyotype of two amphibians of the Seychelles","volume":"48","year":"1978","journal-title":"Genetica"},{"key":"ref_23","first-page":"197","article-title":"Comparative chromosome morphology of Malagasy poison frogs (Amphibia: Ranidae: Mantella)","volume":"47","author":"Pintak","year":"1998","journal-title":"Folia Zool."},{"key":"ref_24","unstructured":"Aprea, G., Andreone, F., Capriglione, T., and Odierna, G. (1998, January 25\u201329). Chromosome banding in several Malagasy anuran species belonging to the genera Aglyptodactylus, Boophis and Mantidactylus. Proceedings of the 9th Ordinary General Meeting of the Societas Herpetologica Europaea, Chamb\u00e9ry, France."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1080\/11250000409356641","article-title":"Evidence for a remarkable stasis of chromosome evolution in Malagasy treefrogs (Boophis, Mantellidae)","volume":"71","author":"Aprea","year":"2004","journal-title":"Ital. J. Zool."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.jcz.2006.10.001","article-title":"Karyological evolution and systematics of Malagasy microhylid frogs","volume":"246","author":"Aprea","year":"2007","journal-title":"Zool. Anz."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1080\/11250000601088564","article-title":"Cytosystematics of hyperoliid frogs: Phylogeny of Heterixalus, low karyotypic variability in hyperoliines and separate phylogenetic position of Leptopelis","volume":"74","author":"Odierna","year":"2007","journal-title":"Ital. J. Zool."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"505","DOI":"10.2108\/zsj.18.505","article-title":"Chromosome data for Malagasy poison frogs (Amphibia: Ranidae: Mantella) and their bearing on taxonomy and phylogeny","volume":"18","author":"Odierna","year":"2001","journal-title":"Zool. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1023\/A:1014949001810","article-title":"Ancient tetraploidy and slow molecular evolution in Scaphiophryne: Ecological correlates of speciation mode in Malagasy relict amphibians","volume":"10","author":"Vences","year":"2002","journal-title":"Chrom. Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1163\/156853803322440763","article-title":"A new frog of the genus Mantidactylus from the rainforests of north-eastern Madagascar, and its karyological affinities","volume":"24","author":"Andreone","year":"2003","journal-title":"Amphibia-Reptilia"},{"key":"ref_31","first-page":"61","article-title":"Karyotypic study of the common Indian toad, Duttaphrynus melanostictus, from Jammu And Kashmir, India","volume":"5","author":"Saba","year":"2014","journal-title":"RW-IRSSJ"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1007\/s13237-014-0101-4","article-title":"Tripathi. Preliminary cytogenetic study and report of ZZ\/ZW sex chromosomes in the bullfrog, Hoplobatrachus tigerinus (Anura, Amphibia) from high altitude area of Jammu and Kashmir, India","volume":"57","author":"Saba","year":"2014","journal-title":"Nucleus"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1163\/15685381-00002942","article-title":"DNA barcoding Madagascar\u2019s amphibian fauna","volume":"35","author":"Perl","year":"2014","journal-title":"Amphibia-Reptilia"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1111\/j.1601-5223.1939.tb02679.x","article-title":"The effect of colchicine on meiosis in Allium","volume":"25","author":"Levan","year":"1939","journal-title":"Hereditas"},{"key":"ref_35","unstructured":"Blair, W.F. (1972). Karyotypes. Evolution of Genus Bufo, University of Texas Press."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1007\/BF00328536","article-title":"Chromosome banding in Amphibia, I. Constitutive heterochromatin and nucleolus organizer regions in Bufo and Hyla","volume":"66","author":"Schmid","year":"1978","journal-title":"Chromosoma"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1007\/BF00287145","article-title":"Chromosome banding in Amphibia, II. Constitutive heterochromatin and nucleolus organizer regions in Ranidae, Microhylidae and Rhacophoridae","volume":"68","author":"Schmid","year":"1978","journal-title":"Chromosoma"},{"key":"ref_38","first-page":"41","article-title":"Karyology of the main groups of African frogs","volume":"15","author":"Morescalchi","year":"1981","journal-title":"Monit. Zool. Ital. Suppl."},{"key":"ref_39","first-page":"55","article-title":"Chromosome lineages in African ranoid frogs","volume":"15","author":"Bogart","year":"1981","journal-title":"Monit. Zool. Ital."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1016\/j.ajhg.2007.11.009","article-title":"Neocentromeres: New insights into centromere structure, disease development, and karyotype evolution","volume":"82","author":"Marshall","year":"2008","journal-title":"Am. J. Hum. Genet."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"14937","DOI":"10.1073\/pnas.0904833106","article-title":"Centromere repositioning in cucurbit species. Implication of the genome impact from centromere activation and inactivation","volume":"106","author":"Han","year":"2007","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_42","unstructured":"John, B., and Gwent, C. (1990). Amphibia. Animal Cytogenetics, Borntraeger."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1093\/genetics\/134.2.487","article-title":"The fertility effects of pericentric inversions in Drosophila melanogaster","volume":"134","author":"Coyne","year":"1993","journal-title":"Genetics"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"129","DOI":"10.3389\/fgene.2014.00129","article-title":"Adaptation through chromosomal inversions in Anopheles","volume":"5","author":"Ayala","year":"2014","journal-title":"Front. Genet."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1038\/nrm.2017.119","article-title":"Ten principles of heterochromatin formation and function","volume":"19","author":"Allshire","year":"2018","journal-title":"Nat. Rev. Mol. Cell Biol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/j.tree.2018.12.005","article-title":"Evolving inversions","volume":"34","author":"Faria","year":"2018","journal-title":"Trends Ecol. Evol."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Guo, X., Su, H., Shi, Q., Fu, S., Wang, J., Zhang, X., Hu, Z., and Han, F. (2016). De Novo Centromere Formation and Centromeric Sequence Expansion in Wheat and its Wide Hybrids. PLoS Genet., 12.","DOI":"10.1371\/journal.pgen.1005997"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"325","DOI":"10.3897\/CompCytogen.v13i4.37687","article-title":"Recurrent variation in the active NOR sites in the monkey frogs of the genus Pithecopus Cope, 1866 (Phyllomedusidae, Anura)","volume":"13","author":"Gama","year":"2019","journal-title":"Comp. Cytogenet."},{"key":"ref_49","first-page":"1","article-title":"Counterstain enhanced chromosome banding","volume":"57","author":"Schweizer","year":"1981","journal-title":"Hum. Genet."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/BF00328469","article-title":"Energy transfer and binding competition between dyes used to enhance staining differentiation in metaphase chromosomes","volume":"79","author":"Sahar","year":"1980","journal-title":"Chromosoma"},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Thakur, J., Packiaraj, J., and Henikoff, S. (2021). Sequence, Chromatin and Evolution of Satellite DNA. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22094309"},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Liao, X., Zhu, W., Zhou, J., Li, H., Xu, X., Zhang, B., and Gao, X. (2023). Repetitive DNA sequence detection and its role in the human genome. Commun. Biol., 6.","DOI":"10.1038\/s42003-023-05322-y"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1159\/000133442","article-title":"Chromosome banding in Amphibia: XVIII. Karyotype evolution and genomic size variation in Pleurodema (Anura, Leptodactylidae)","volume":"62","author":"Schmid","year":"1993","journal-title":"Cytogenet. Cell Genet."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1007\/BF02100197","article-title":"Genome variations in the transition from amphibians to reptiles","volume":"33","author":"Olmo","year":"1991","journal-title":"J. Mol. Evol."},{"key":"ref_55","unstructured":"Verma, R.S. (1988). Heterochromatin: Molecular and Structural Aspects, Cambridge University Press."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1111\/j.1469-7998.2011.00829.x","article-title":"Genome duplication in amphibians and fish: An extended synthesis: Polyploidy in amphibians and fish","volume":"284","author":"Mable","year":"2011","journal-title":"J. Zool."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1038\/hdy.2012.79","article-title":"Polyploidy and its effect on evolutionary success: Old questions revisited with new tools","volume":"110","author":"Madlung","year":"2013","journal-title":"Heredity"}],"container-title":["Genes"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4425\/16\/12\/1464\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,8]],"date-time":"2025-12-08T10:45:25Z","timestamp":1765190725000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4425\/16\/12\/1464"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,8]]},"references-count":57,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["genes16121464"],"URL":"https:\/\/doi.org\/10.3390\/genes16121464","relation":{},"ISSN":["2073-4425"],"issn-type":[{"value":"2073-4425","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,8]]}}}