ORIGINAL ARTICLE Evolution of the parthenogenetic rock lizard hybrid karyotype: Robertsonian translocation between two maternal chromosomes in Darevskia rostombekowi Victor Spangenberg 1 & Oxana Kolomiets 1 & Ilona Stepanyan 2 & Eduard Galoyan 3 & Marcelo de Bello Cioffi 4,5 & Elena Martynova 6 & Irena Martirosyan 7 & Tatiana Grishaeva 1 & Felix Danielyan 8 & Ahmed Al-Rikabi 5 & Thomas Liehr 5 & Marine Arakelyan 8 Received: 18 May 2020 /Revised: 26 June 2020 /Accepted: 26 October 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Darevskia rostombekowi, the most outstanding of the seven known parthenogenetic species in the genus Darevskia, is the result of an ancestral cross between two bisexual species Darevskia raddei and Darevskia portschinskii. The chromosomal set of this species includes a unique submetacentric autosomal chromosome; the origin of this chromosome was unresolved as only acrocentric chromosomes are described in the karyotypes of Darevskia genus normally. Here, we applied a suite of molecular cytogenetic techniques, including the mapping of telomeric (TTAGGG) n repeats using fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), and whole-chromosome painting (WCP) in both D. rostombekowi and parental (D. portschinskii and D. raddei) species. The obtained results in total suggest that a de novo chromosomal rearrangement via Robertsonian translocation (centric fusion) between two maternal (D. raddei) acrocentric chromosomes of different size was involved in the formation of this unique submetacentric chromosome present in the parthenogenetic species D. rostombekowi. Our findings provide new data in specific and rapid evolutional processes of a unisexual reptile species karyotype. Keywords Fluorescence in situ hybridization . Robertsonian translocation . Parthenogenesis . Reticulate evolution . Whole-chromosome painting . Comparative genomic hybridization . Pericentromeric DNA . Interstitial telomeric sites Introduction The species of the Lacertidae family display the unifor- mity of karyotypes and chromosome numbers. Most of the studied species show the same diploid number 2n = 38 consisting of 36 acrocentric macro- and 2 microchromosomes (Nascetti et al. 1982). However, sev- eral taxa have the basic diploid number 2n = 36; similar karyotypic macrostructure, with all chromosomes being acrocentric; and no microchromosomes (Rojo Oróns 2015). The absence of microchromosomes could be a con- sequence of fusion of the micro- and macrochromosomes (Olmo et al. 1984; Olmo et al. 1986). Weak interstitial telomeric sites were detected in macrochromosomes of two species in the genus Timon having 2n = 36; this was considered the markers of chromosomal rearrangements (Suwala et al. 2020). As exceptions in Lacertidae have to be mentioned three Iberian rock lizard species with 2n = 26 or 2n = 24. They have a mix of biarmed (probably Victor Spangenberg, Oxana Kolomiets, Ilona Stepanyan, Ahmed Al- Rikabi, Thomas Liehr and Marine Arakelyan contributed equally to this work. * Victor Spangenberg v.spangenberg@gmail.com 1 Vavilov Institute of General Genetics, RAS, Gubkin 3, Moscow 119991, Russia 2 Scientific Center of Zoology and Hydroecology, Yerevan, Armenia 3 Severtsov Institute of Ecology and Evolution, RAS, Moscow, Russia 4 Laboratório de Citogenética de Peixes, Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil 5 Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany 6 Skolkovo Institute of Science and Technology, Moscow, Russia 7 Institute of Gene Biology, RAS, Moscow, Russia 8 Department of Zoology, Yerevan State University, Yerevan, Armenia Chromosoma https://doi.org/10.1007/s00412-020-00744-7