Article
Cell Biology
Barbora Augstenova, Eleonora Pensabene, Lukas Kratochvil, Michail Rovatsos
Summary: Anguimorphan lizards are a group of squamate reptiles with wide geographical distribution and morphological variability. Their karyotypes show significant variation across different lineages, with Anguids exhibiting the most variability. The study documented differentiated sex chromosomes in monitors and helodermatids, as well as in some anguids, and also revealed a rare case of spontaneous triploidy in Varanus primordius.
Article
Biochemistry & Molecular Biology
Alexander Kostmann, Barbora Augstenova, Daniel Frynta, Lukas Kratochvil, Michail Rovatsos
Summary: Lizards of the Scincoidea clade, including cordylids, gerrhosaurids, skinks, and xantusiids, exhibit almost worldwide distribution and significant ecological and morphological diversity. Despite limited variability in cytogenetic traits, different species show conservation in diploid chromosome numbers but significant variation in chromosome morphology and the presence of interstitial telomeric sequences. Sex chromosomes, identified as XX/XY, are only found in Tiliqua scincoides within this clade, indicating a generally poor stage of differentiation in sex chromosomes among these lizards.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Genetics & Heredity
Tomas Charvat, Barbora Augstenova, Daniel Frynta, Lukas Kratochvil, Michail Rovatsos
Summary: The recent discovery of independently evolved XX/XY sex determination systems in Python and Boa snakes has prompted further research into poorly studied snake lineages to understand the evolution of sex chromosomes. In this study, seven species from different genera were examined, revealing variability in the distribution of heterochromatin, telomeric repeats, and rDNA loci. The results suggest that these species likely have homomorphic, poorly differentiated sex chromosomes, as no sex-specific differences were detected.
Article
Genetics & Heredity
Alexander Kostmann, Lukas Kratochvil, Michail Rovatsos
Summary: Scincoidea is a reptilian clade with diversity in sex-determining systems. It has been debated whether skinks have sex chromosomes variations or even lack of sex chromosomes. While ZZ/ZW sex chromosomes have been identified in some scincoidean lizards, they are poorly differentiated and often undetectable by cytogenetic methods. However, this study reports the presence of ZZ/ZW sex chromosomes in the plated lizard Zonosaurus madagascariensis, suggesting a different pattern of sex chromosome evolution in this species.
Article
Genetics & Heredity
Gabriela Chrostek, Aleksandra Domaradzka, Alona Yurchenko, Lukas Kratochvil, Sofia Mazzoleni, Michail Rovatsos
Summary: This study applied both conventional and molecular cytogenetic analyses in seven species of geckos, revealing the presence of interstitial telomeric repeats in four species. However, the origin of these repeats remains unclear. Additionally, sex chromosomes were not detected in any examined species, suggesting the presence of poorly differentiated sex chromosomes or environmental sex determination. Future studies should investigate the impact of temperature and conduct genome-wide analyses to determine the mode of sex determination in these species.
Article
Genetics & Heredity
Lorenzo Clemente, Sofia Mazzoleni, Eleonora Pensabene, Tomas Protiva, Philipp Wagner, Uwe Fritz, Lukas Kratochvil, Michail Rovatsos
Summary: The Asian box turtle genus Cuora consists of 13 species distributed in Southeast Asia. The populations of these species are rapidly declining due to human activities. Research shows that all species have a diploid chromosome number of 2n = 52, with similar karyotypes and poorly differentiated sex chromosomes.
Article
Developmental Biology
Alexander Kostmann, Lukas Kratochvil, Michail Rovatsos
Summary: This study applied both conventional and molecular cytogenetic methods to investigate the sex chromosomes of the Peters' keeled plated lizard (Tracheloptychus petersi) and found accumulations of rDNA loci in a pair of microchromosomes in males, but only in a single microchromosome in females. The restriction of observed heterozygosity to females suggests a putative ZZ/ZW system of sex chromosomes in this species, which is the first report of sex chromosomes in a gerrhosaurid lizard. All other cytogenetic methods did not show sex-specific signals, indicating that the sex chromosomes of T. petersi are poorly differentiated in sequence content.
SEXUAL DEVELOPMENT
(2021)
Article
Genetics & Heredity
Kevin Santos da Silva, Larissa Glugoski, Marcelo Ricardo Vicari, Augusto Cesar Paes de Souza, Renata Coelho Rodrigues Noronha, Julio Cesar Pieczarka, Cleusa Yoshiko Nagamachi
Summary: The Ancistrus genus demonstrates extensive chromosomal diversity, including the occurrence of heteromorphic sex chromosomes and unstable repetitive sequences. These findings provide important insights into the evolution and genetic mechanisms of the Ancistrus genus.
FRONTIERS IN GENETICS
(2022)
Article
Biochemistry & Molecular Biology
Analiza Fernanda Cavenagh, Matheus Pires Rincao, Felipe Cordeiro Dias, Antonio Domingos Brescovit, Ana Lucia Dias
Summary: The study reveals intra and interspecific chromosomal variability in the genus Lycosa, suggesting that chromosomal rearrangements are associated with the diversification of diploid number and sexual chromosome systems in this group of spiders.
GENETICS AND MOLECULAR BIOLOGY
(2022)
Article
Entomology
Natalia Golub, Viktor B. Golub, Boris A. Anokhin, Valentina G. Kuznetsova
Summary: Tingidae, or lace bugs, is a family of herbivorous true bugs with approximately 2600 identified species. This study examined the karyotypes of 16 lace bug species and analyzed the information available on lace bug karyotypes. The study found that lace bugs have conservative karyotypes, different sex chromosome systems, and different patterns of 18S rDNA chromosomal localization. The search for chromosomal landmarks is important for further understanding lace bug cytogenetics.
Article
Biology
Francisco de M. C. Sassi, Orlando Moreira-Filho, Geize A. Deon, Alexandr Sember, Luiz A. C. Bertollo, Thomas Liehr, Vanessa C. S. Oliveira, Patrik F. Viana, Eliana Feldberg, Marcelo R. Vicari, Marcelo de B. Cioffi
Summary: Fishes from the genus Harttia in the Amazon region exhibit karyotype variability, with some species possessing different chromosome numbers and showing signs of sex chromosome differentiation. This study provides new evidence supporting Harttia as a valuable model for investigating teleost karyotype and sex chromosome dynamics.
Article
Genetics & Heredity
Natalia V. Golub, Anna Maryanska-Nadachowska, Boris A. Anokhin, Valentina G. Kuznetsova
Summary: The study investigated the male karyotypes and meiosis in 10 species of Lygaeoidea. The results showed a range of chromosome numbers and the presence of an XY system and m-chromosomes. The study also found that the Lygaeoidea lack the canonical insect telomere motif (TTAGG)(n) and speculated on the presence of other telomere repeat motifs.
Article
Biochemistry & Molecular Biology
Magdalena Senderowicz, Teresa Nowak, Hanna Weiss-Schneeweiss, Laszlo Papp, Bozena Kolano
Summary: This study investigated the chromosome evolution of Crepis plants by analyzing the chromosome base number and organization of rDNA loci in 39 species. The results showed that despite variations in rDNA loci organization, most species had rDNA loci on the same chromosome arm. Comparative analysis revealed multiple independent gains of rDNA loci and repositioning during diversification and speciation. These findings provide important insights into the evolutionary mechanisms and speciation of Crepis plants.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Marine & Freshwater Biology
Simiao Alefe Soares da Silva, Paulo Augusto de Lima-Filho, Clovis Coutinho da Motta-Neto, Gideao Wagner Werneck Felix da Costa, Marcelo de Bello Cioffi, Luiz Antonio Carlos Bertollo, Wagner Franco Molina
Summary: The order Gobiiformes consists of over 2200 species and is considered one of the most diverse groups among teleost fishes. This study expanded cytogenetic data for four neotropical species in the Eleotridae family and used a meta-analytical approach to explore the karyotype diversification in relation to biological aspects.
MARINE LIFE SCIENCE & TECHNOLOGY
(2021)
Article
Zoology
Marcello Mezzasalma, Gaetano Odierna
Summary: The molecular and karyological analysis of Coronella austriaca revealed distinct genetic and chromosomal differences in different geographical areas of the species distribution, indicating the presence of diverse evolutionary clades within the species. Additionally, the study identified a ZZ/ZW sex chromosome system with female heterogamety in C. austriaca, highlighting chromosomal diversification among distinct geographical areas.
ACTA HERPETOLOGICA
(2021)
Letter
Biochemistry & Molecular Biology
Lukas Kratochvil, Michail Rovatsos
Article
Developmental Biology
Dmitrij Dedukh, Marie Altmanova, Jiri Klima, Lukas Kratochvil
Summary: Obligate parthenogenesis has evolved multiple times in reptiles through interspecific hybridization, resulting in the formation of diploid and triploid lineages. This study shows that oocytes in several widespread parthenogenetic complexes of geckos undergo meiosis and produce unreduced eggs through premeiotic endoreplication, allowing for the emergence of fertile polyploid lineages within parthenogenetic complexes.
Article
Biodiversity Conservation
Ivan Rehak, David Fischer, Lukas Kratochvil, Michail Rovatsos
Summary: The northernmost population of the Balkan wall lizards was recently discovered in the Czech Republic. Genetic analysis revealed three unique haplotypes closely related to those found in populations from the central/north Balkans and Hungary. These findings suggest that the Czech population either originated locally or was recently introduced and expanded.
BIODIVERSITY DATA JOURNAL
(2022)
Article
Evolutionary Biology
Jiri Smid, Marek Uvizl, Mohammed Shobrak, Salem Busais, Al Faqih Ali Salim, Raed Hamoud M. AlGethami, Abdulaziz Raqi AlGethami, Abdulkarim Saleh K. Alanazi, Saad Dasman Alsubaie, Michail Rovatsos, Lucie Novakova, Tomas Mazuch, Salvador Carranza
Summary: This study investigates the genetic, morphological, and ecological diversification of a Hemidactylus clade in the Arabian Peninsula and Africa. The researchers discovered four undescribed species within the clade, two from Arabia and two from Ethiopia. The study also highlights the underestimated role of the southern Arabian coastal desert as a local biodiversity hotspot.
ORGANISMS DIVERSITY & EVOLUTION
(2023)
Article
Genetics & Heredity
Tomas Charvat, Barbora Augstenova, Daniel Frynta, Lukas Kratochvil, Michail Rovatsos
Summary: The recent discovery of independently evolved XX/XY sex determination systems in Python and Boa snakes has prompted further research into poorly studied snake lineages to understand the evolution of sex chromosomes. In this study, seven species from different genera were examined, revealing variability in the distribution of heterochromatin, telomeric repeats, and rDNA loci. The results suggest that these species likely have homomorphic, poorly differentiated sex chromosomes, as no sex-specific differences were detected.
Article
Biochemistry & Molecular Biology
Jana Stundlova, Monika Hospodarska, Karolina Luksikova, Anna Volenikova, Tomas Pavlica, Marie Altmanova, Annekatrin Richter, Martin Reichard, Martina Dalikova, Sarka Pelikanova, Anatolie Marta, Sergey A. Simanovsky, Matyas Hirman, Marek Jankasek, Tomas Dvorak, Joerg Bohlen, Petr Rab, Christoph Englert, Petr Nguyen, Alexandr Sember
Summary: This study investigated the evolution of sex chromosomes in two sister species of African annual killifishes and found that both species shared homomorphic sex chromosomes that evolved prior to their divergence. The study also revealed differences in repetitive DNA sequences between the sex chromosomes, which may result from high turnover of repeat sequences and may not closely relate to the divergence inferred from earlier SNP analyses.
CHROMOSOME RESEARCH
(2022)
Article
Genetics & Heredity
Gabriela Chrostek, Aleksandra Domaradzka, Alona Yurchenko, Lukas Kratochvil, Sofia Mazzoleni, Michail Rovatsos
Summary: This study applied both conventional and molecular cytogenetic analyses in seven species of geckos, revealing the presence of interstitial telomeric repeats in four species. However, the origin of these repeats remains unclear. Additionally, sex chromosomes were not detected in any examined species, suggesting the presence of poorly differentiated sex chromosomes or environmental sex determination. Future studies should investigate the impact of temperature and conduct genome-wide analyses to determine the mode of sex determination in these species.
Article
Genetics & Heredity
Alexander Kostmann, Lukas Kratochvil, Michail Rovatsos
Summary: Scincoidea is a reptilian clade with diversity in sex-determining systems. It has been debated whether skinks have sex chromosomes variations or even lack of sex chromosomes. While ZZ/ZW sex chromosomes have been identified in some scincoidean lizards, they are poorly differentiated and often undetectable by cytogenetic methods. However, this study reports the presence of ZZ/ZW sex chromosomes in the plated lizard Zonosaurus madagascariensis, suggesting a different pattern of sex chromosome evolution in this species.
Article
Cell Biology
Eleonora Pensabene, Alona Yurchenko, Lukas Kratochvil, Michail Rovatsos
Summary: Geckos, especially the Madagascar leaf-tail geckos of the Uroplatus genus, provide a great model for studying the evolution of sex determination. Our research reveals the presence of highly heterochromatic W chromosomes in these geckos, with a specific region on the Z chromosome shared with chicken chromosomes. Despite differences in their W chromosomes, all tested species of leaf-tail geckos share homologous sex chromosomes. This finding highlights the importance of studying the convergence of sex chromosomes from the same genomic region.
