TY - JOUR
T1 - Cross-species chromosome painting and repetitive DNA mapping illuminate the karyotype evolution in true crocodiles (Crocodylidae)
AU - Sales-Oliveira, Vanessa
AU - Altmanová, Marie
AU - Gvoždík, Václav
AU - Kretschmer, Rafael
AU - Ezaz, Tariq
AU - Liehr, Thomas
AU - Padutsch, Niklas
AU - Badjedjea, Gabriel
AU - Utsunomia, Ricardo
AU - Tanomtong, Alongklod
AU - Cioffi, Marcelo
N1 - Funding Information:
V.C.S.O. was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasil (CAPES) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (200401/2022–0). M.A. was supported by the Charles University Research Centre program 204069 and by the Czech Science Foundation Project No. 20-27236 J. V.G. was supported by the Czech Science Foundation (23-07331S), and the Ministry of Culture of the Czech Republic (DKRVO 2019–2023/6.VII.e, National Museum, 00023272). M.d.B.C. was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (302928/2021–9), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (2020/11772–8). MBC and TL were supported by Alexander von Humboldt-Stiftung. We acknowledge support by the German Research Foundation Projekt-Nr. 512648189 and the Open Access Publication Fund of the Thueringer Universitaets- und Landesbibliothek Jena. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasil (CAPES), Finance Code 001.
Publisher Copyright:
© 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2023/7
Y1 - 2023/7
N2 - Crocodilians have maintained very similar karyotype structures and diploid chromosome numbers for around 100 million years, with only minor variations in collinearity. Why this karyotype structure has largely stayed unaltered for so long is unclear. In this study, we analyzed the karyotypes of six species belonging to the genera Crocodylus and Osteolaemus (Crocodylidae, true crocodiles), among which the Congolian endemic O. osborni was included and investigated. We utilized various techniques (differential staining, fluorescence in situ hybridization with repetitive DNA and rDNA probes, whole chromosome painting, and comparative genomic hybridization) to better understand how crocodile chromosomes evolved. We studied representatives of three of the four main diploid chromosome numbers found in crocodiles (2n = 30/32/38). Our data provided new information about the species studied, including the identification of four major chromosomal rearrangements that occurred during the karyotype diversification process in crocodiles. These changes led to the current diploid chromosome numbers of 2n = 30 (fusion) and 2n = 38 (fissions), derived from the ancestral state of 2n = 32. The conserved cytogenetic tendency in crocodilians, where extant species keep near-ancestral state, contrasts with the more dynamic karyotype evolution seen in other major reptile groups.
AB - Crocodilians have maintained very similar karyotype structures and diploid chromosome numbers for around 100 million years, with only minor variations in collinearity. Why this karyotype structure has largely stayed unaltered for so long is unclear. In this study, we analyzed the karyotypes of six species belonging to the genera Crocodylus and Osteolaemus (Crocodylidae, true crocodiles), among which the Congolian endemic O. osborni was included and investigated. We utilized various techniques (differential staining, fluorescence in situ hybridization with repetitive DNA and rDNA probes, whole chromosome painting, and comparative genomic hybridization) to better understand how crocodile chromosomes evolved. We studied representatives of three of the four main diploid chromosome numbers found in crocodiles (2n = 30/32/38). Our data provided new information about the species studied, including the identification of four major chromosomal rearrangements that occurred during the karyotype diversification process in crocodiles. These changes led to the current diploid chromosome numbers of 2n = 30 (fusion) and 2n = 38 (fissions), derived from the ancestral state of 2n = 32. The conserved cytogenetic tendency in crocodilians, where extant species keep near-ancestral state, contrasts with the more dynamic karyotype evolution seen in other major reptile groups.
KW - Chromosome
KW - Crocodylia
KW - Cytogenomics
KW - FISH
KW - Molecular cytogenetics
KW - WCP
UR - http://www.scopus.com/inward/record.url?scp=85165694088&partnerID=8YFLogxK
U2 - 10.1007/s00412-023-00806-6
DO - 10.1007/s00412-023-00806-6
M3 - Article
C2 - 37493806
AN - SCOPUS:85165694088
SN - 0009-5915
VL - 132
SP - 289
EP - 303
JO - Chromosoma
JF - Chromosoma
IS - 4
ER -