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Mezzasalma M, Odierna G, Macirella R, Brunelli E. Comparative Cytogenetics of the Malagasy Ground Geckos of the Paroedura bastardi and Paroedura picta Species Groups. Animals (Basel) 2024; 14:1708. [PMID: 38891755 PMCID: PMC11171197 DOI: 10.3390/ani14111708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 05/27/2024] [Accepted: 06/03/2024] [Indexed: 06/21/2024] Open
Abstract
We present a comparative chromosome study of several taxa of the Malagasy ground geckos of the Paroedura bastardi and P. picta species groups. We employed a preliminary molecular analysis using a trait of the mitochondrial 16S rRNA gene (of about 570 bp) to assess the taxonomic status of the samples studied and a cytogenetic analysis with standard karyotyping (5% Giemsa solution), silver staining (Ag-NOR staining) and sequential C-banding (C-banding + Giemsa and + fluorochromes). Our results show that all the taxa studied of the P. bastardi group (P. ibityensis, P. rennerae and P. cf. guibeae) have a similar karyotype composed of 2n = 34 chromosomes, with two metacentric pairs (1 and 3) and all other pairs being acrocentric. Chromosome diversification in the P. bastardi group was mainly linked to the diversification of heteromorphic sex chromosome systems (ZZ/ZW) in P. ibityensis and P. rennerae, while no heteromorphic sex chromosome pair was found in P. cf. guibeae. The two taxa investigated of the P. picta species group (here named P. picta and P. cf. picta based on molecular data) showed the same chromosome number of 2n = 36, mostly acrocentric elements, but differed in the number of metacentric elements, probably as a result of an inversion at chromosome pair 2. We highlight that the genus Paroedura is characterized by the independent diversification of heterogametic sex chromosomes in different evolutionary lineages and, similarly to other phylogenetically related gecko genera, by a progressive formation of a biarmed element by means of tandem fusions and inversions of distinct pairs.
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Affiliation(s)
- Marcello Mezzasalma
- Department of Biology, Ecology and Earth Science, University of Calabria, Via P. Bucci 4/B, 87036 Rende, Italy; (R.M.); (E.B.)
| | - Gaetano Odierna
- Independent Researcher, Via Michelangelo 123, 81031 Aversa, Italy
| | - Rachele Macirella
- Department of Biology, Ecology and Earth Science, University of Calabria, Via P. Bucci 4/B, 87036 Rende, Italy; (R.M.); (E.B.)
| | - Elvira Brunelli
- Department of Biology, Ecology and Earth Science, University of Calabria, Via P. Bucci 4/B, 87036 Rende, Italy; (R.M.); (E.B.)
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Yurchenko A, Pšenička T, Mora P, Ortega JAM, Baca AS, Rovatsos M. Cytogenetic Analysis of Satellitome of Madagascar Leaf-Tailed Geckos. Genes (Basel) 2024; 15:429. [PMID: 38674364 PMCID: PMC11049218 DOI: 10.3390/genes15040429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Satellite DNA (satDNA) consists of sequences of DNA that form tandem repetitions across the genome, and it is notorious for its diversity and fast evolutionary rate. Despite its importance, satDNA has been only sporadically studied in reptile lineages. Here, we sequenced genomic DNA and PCR-amplified microdissected W chromosomes on the Illumina platform in order to characterize the monomers of satDNA from the Henkel's leaf-tailed gecko U. henkeli and to compare their topology by in situ hybridization in the karyotypes of the closely related Günther's flat-tail gecko U. guentheri and gold dust day gecko P. laticauda. We identified seventeen different satDNAs; twelve of them seem to accumulate in centromeres, telomeres and/or the W chromosome. Notably, centromeric and telomeric regions seem to share similar types of satDNAs, and we found two that seem to accumulate at both edges of all chromosomes in all three species. We speculate that the long-term stability of all-acrocentric karyotypes in geckos might be explained from the presence of specific satDNAs at the centromeric regions that are strong meiotic drivers, a hypothesis that should be further tested.
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Affiliation(s)
- Alona Yurchenko
- Department of Ecology, Faculty of Science, Charles University, 128 44 Prague, Czech Republic; (A.Y.); (T.P.)
| | - Tomáš Pšenička
- Department of Ecology, Faculty of Science, Charles University, 128 44 Prague, Czech Republic; (A.Y.); (T.P.)
| | - Pablo Mora
- Department of Experimental Biology, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas s/n, E-23071 Jaen, Spain; (P.M.); (J.A.M.O.); (A.S.B.)
| | - Juan Alberto Marchal Ortega
- Department of Experimental Biology, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas s/n, E-23071 Jaen, Spain; (P.M.); (J.A.M.O.); (A.S.B.)
| | - Antonio Sánchez Baca
- Department of Experimental Biology, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas s/n, E-23071 Jaen, Spain; (P.M.); (J.A.M.O.); (A.S.B.)
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, 128 44 Prague, Czech Republic; (A.Y.); (T.P.)
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Rico-Porras JM, Mora P, Palomeque T, Montiel EE, Cabral-de-Mello DC, Lorite P. Heterochromatin Is Not the Only Place for satDNAs: The High Diversity of satDNAs in the Euchromatin of the Beetle Chrysolina americana (Coleoptera, Chrysomelidae). Genes (Basel) 2024; 15:395. [PMID: 38674330 PMCID: PMC11049206 DOI: 10.3390/genes15040395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/16/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024] Open
Abstract
The satellitome of the beetle Chrysolina americana Linneo, 1758 has been characterized through chromosomal analysis, genomic sequencing, and bioinformatics tools. C-banding reveals the presence of constitutive heterochromatin blocks enriched in A+T content, primarily located in pericentromeric regions. Furthermore, a comprehensive satellitome analysis unveils the extensive diversity of satellite DNA families within the genome of C. americana. Using fluorescence in situ hybridization techniques and the innovative CHRISMAPP approach, we precisely map the localization of satDNA families on assembled chromosomes, providing insights into their organization and distribution patterns. Among the 165 identified satDNA families, only three of them exhibit a remarkable amplification and accumulation, forming large blocks predominantly in pericentromeric regions. In contrast, the remaining, less abundant satDNA families are dispersed throughout euchromatic regions, challenging the traditional association of satDNA with heterochromatin. Overall, our findings underscore the complexity of repetitive DNA elements in the genome of C. americana and emphasize the need for further exploration to elucidate their functional significance and evolutionary implications.
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Affiliation(s)
- José M. Rico-Porras
- Department of Experimental Biology, Genetics Area, University of Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain; (J.M.R.-P.); (P.M.); (T.P.)
| | - Pablo Mora
- Department of Experimental Biology, Genetics Area, University of Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain; (J.M.R.-P.); (P.M.); (T.P.)
| | - Teresa Palomeque
- Department of Experimental Biology, Genetics Area, University of Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain; (J.M.R.-P.); (P.M.); (T.P.)
| | - Eugenia E. Montiel
- Department of Biology, Genetics, Faculty of Sciences, Autonomous University of Madrid, 28049 Madrid, Spain;
- Center for Research in Biodiversity and Global Change, Autonomous University of Madrid, 28049 Madrid, Spain
| | - Diogo C. Cabral-de-Mello
- Department of General and Applied Biology, Institute of Biosciences/IB, UNESP—São Paulo State University, Rio Claro 13506-900, SP, Brazil;
| | - Pedro Lorite
- Department of Experimental Biology, Genetics Area, University of Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain; (J.M.R.-P.); (P.M.); (T.P.)
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Vidal JAD, Sassi FDMC, de Moraes RLR, Artoni RF, Liehr T, Cioffi MB, de Almeida MC. Giant Sex Chromosomes in Omophoita Species (Coleoptera, Chrysomelidae): Structural and Evolutionary Relationships Revealed by Zoo-FISH and Comparative Genomic Hybridization (CGH). INSECTS 2023; 14:insects14050440. [PMID: 37233068 DOI: 10.3390/insects14050440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023]
Abstract
The beetles of the subtribe Oedionychina (Chrysomelidae, Alticinae) are the only ones that have the atypical giant and achiasmatic sex chromosomes, which are substantially larger than the autosomes. Previous cytogenetic analyses suggest a large accumulation of repetitive DNA in the sex chromosomes. In this study, we examined the similarity of X and Y chromosomes in four Omophoita species and compared genomic differentiation to better understand the evolutionary process and the giant sex chromosomes origin. Intraspecific genomic comparation using male and female genomes of O. octoguttata and interespecific analyses using genomic DNA of O. octoguttata, O. sexnotata, O. magniguttis, and O. personata were performed. In addition, whole chromosome painting (WCP) experiments were performed with X and Y chromosome probes of O. octogutatta. CGH analysis revealed great genomic similarity between the sexes and a sex-specific region on the Y chromosome, and interspecific analysis revealed a genomic divergence between species. In contrast, WCP results revealed that the sex chromosomes of O. octoguttata have high intra- and interspecific similarity with the studied species. Our data support a common origin under the canonical evolution of the sex chromosomes in this group, as they have high genomic similarity between them.
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Affiliation(s)
- Jhon A D Vidal
- Laboratório de Citogenética de Peixes, Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luiz Km. 235, C.P. 676, São Carlos 13565-905, Brazil
- Laboratório de Genética e Evolução, Departamento de Biologia Estrutural Molecular e Genética, Universidade Estadual de Ponta Grossa (UEPG), Av. Carlos Cavalcanti, 4748, Ponta Grossa 84030-900, Brazil
| | - Francisco de M C Sassi
- Laboratório de Citogenética de Peixes, Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luiz Km. 235, C.P. 676, São Carlos 13565-905, Brazil
| | - Renata L R de Moraes
- Laboratório de Citogenética de Peixes, Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luiz Km. 235, C.P. 676, São Carlos 13565-905, Brazil
| | - Roberto F Artoni
- Laboratório de Genética e Evolução, Departamento de Biologia Estrutural Molecular e Genética, Universidade Estadual de Ponta Grossa (UEPG), Av. Carlos Cavalcanti, 4748, Ponta Grossa 84030-900, Brazil
| | - Thomas Liehr
- Institute of Human Genetics, University Hospital Jena, 07747 Jena, Germany
| | - Marcelo B Cioffi
- Laboratório de Citogenética de Peixes, Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luiz Km. 235, C.P. 676, São Carlos 13565-905, Brazil
- Institute of Human Genetics, University Hospital Jena, 07747 Jena, Germany
| | - Mara C de Almeida
- Laboratório de Genética e Evolução, Departamento de Biologia Estrutural Molecular e Genética, Universidade Estadual de Ponta Grossa (UEPG), Av. Carlos Cavalcanti, 4748, Ponta Grossa 84030-900, Brazil
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Pensabene E, Yurchenko A, Kratochvíl L, Rovatsos M. Madagascar Leaf-Tail Geckos ( Uroplatus spp.) Share Independently Evolved Differentiated ZZ/ZW Sex Chromosomes. Cells 2023; 12:cells12020260. [PMID: 36672195 PMCID: PMC9856856 DOI: 10.3390/cells12020260] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/10/2023] Open
Abstract
Geckos are an excellent group to study the evolution of sex determination, as they possess a remarkable variability ranging from a complete absence of sex chromosomes to highly differentiated sex chromosomes. We explored sex determination in the Madagascar leaf-tail geckos of the genus Uroplatus. The cytogenetic analyses revealed highly heterochromatic W chromosomes in all three examined species (Uroplatus henkeli, U. alluaudi, U. sikorae). The comparative gene coverage analysis between sexes in U. henkeli uncovered an extensive Z-specific region, with a gene content shared with the chicken chromosomes 8, 20, 26 and 28. The genomic region homologous to chicken chromosome 28 has been independently co-opted for the role of sex chromosomes in several vertebrate lineages, including monitors, beaded lizards and monotremes, perhaps because it contains the amh gene, whose homologs were repeatedly recruited as a sex-determining locus. We demonstrate that all tested species of leaf-tail geckos share homologous sex chromosomes despite the differences in shape and size of their W chromosomes, which are not homologous to the sex chromosomes of other closely related genera. The rather old (at least 40 million years), highly differentiated sex chromosomes of Uroplatus geckos can serve as a great system to study the convergence of sex chromosomes evolved from the same genomic region.
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Romanenko SA, Prokopov DY, Proskuryakova AA, Davletshina GI, Tupikin AE, Kasai F, Ferguson-Smith MA, Trifonov VA. The Cytogenetic Map of the Nile Crocodile ( Crocodylus niloticus, Crocodylidae, Reptilia) with Fluorescence In Situ Localization of Major Repetitive DNAs. Int J Mol Sci 2022; 23:13063. [PMID: 36361851 PMCID: PMC9656864 DOI: 10.3390/ijms232113063] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 01/16/2024] Open
Abstract
Tandemly arranged and dispersed repetitive DNA sequences are important structural and functional elements that make up a significant portion of vertebrate genomes. Using high throughput, low coverage whole genome sequencing followed by bioinformatics analysis, we have identified seven major tandem repetitive DNAs and two fragments of LTR retrotransposons in the genome of the Nile crocodile (Crocodylus niloticus, 2n = 32). The repeats showed great variability in structure, genomic organization, and chromosomal distribution as revealed by fluorescence in situ hybridization (FISH). We found that centromeric and pericentromeric heterochromatin of C. niloticus is composed of previously described in Crocodylus siamensis CSI-HindIII and CSI-DraI repetitive sequence families, a satellite revealed in Crocodylus porosus, and additionally contains at least three previously unannotated tandem repeats. Both LTR sequences identified here belong to the ERV1 family of endogenous retroviruses. Each pericentromeric region was characterized by a diverse set of repeats, with the exception of chromosome pair 4, in which we found only one type of satellite. Only a few repeats showed non-centromeric signals in addition to their centromeric localization. Mapping of 18S-28S ribosomal RNA genes and telomeric sequences (TTAGGG)n did not demonstrate any co-localization of these sequences with revealed centromeric and pericentromeric heterochromatic blocks.
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Affiliation(s)
- Svetlana A. Romanenko
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Russia
| | - Dmitry Yu. Prokopov
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Russia
| | - Anastasia A. Proskuryakova
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Russia
| | - Guzel I. Davletshina
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Russia
- Institute of Cytology and Genetics, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Russia
| | - Alexey E. Tupikin
- Institute of Chemical Biology and Fundamental Medicine, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Russia
| | - Fumio Kasai
- Japanese Collection of Research Bioresources (JCRB) Cell Bank, Laboratory of Cell Cultures, The National Institute of Biomedical Innovation, Health and Nutrition, Saito-Asagi, Ibaraki 567-0085, Osaka, Japan
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | | | - Vladimir A. Trifonov
- Institute of Molecular and Cellular Biology, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Russia
- Department of Natural Science, Novosibirsk State University, 630090 Novosibirsk, Russia
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Guzmán-Markevich K, Roco ÁS, Ruiz-García A, Bullejos M. Cytogenetic Analysis in the Toad Species Bufo spinosus, Bufotes viridis and Epidalea calamita (Anura, Bufonidae) from the Mediterranean Area. Genes (Basel) 2022; 13:genes13081475. [PMID: 36011385 PMCID: PMC9408106 DOI: 10.3390/genes13081475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/13/2022] [Accepted: 08/14/2022] [Indexed: 11/06/2022] Open
Abstract
Taxonomy in Bufonidae witnessed notable transformations. Bufotes viridis and Epidalea calamita, previously included in genus Bufo, were relocated in other genera, while the genus Bufo was restricted to members of the earlier Bufo bufo group. On the other hand, Bufo bufo sensu lato now includes four species: Bufo bufo, Bufo spinosus, Bufo verrucosissimus and Bufo eichwaldi. In this study, we examined three species of three Bufonidae genera (B. spinosus, B. viridis and E. calamita) by conventional (C-banding and Ag-NOR staining) and molecular (in situ hybridization with probes for telomeric repeats and rDNA loci, and genomic in situ hybridization (GISH)) cytogenetic methods. C-banding patterns are reported for the first time for B. spinosus and E. calamita populations from Iberian Peninsula and for B. viridis from Greece, and reveal several differences with the reported C-banded karyotypes described for other European populations of these species. Silver staining shows size heteromorphisms of the signals at the Nucleolar Organizing Region (NOR). By contrast, FISH with ribosomal probes only reveal size heteromorphism of rDNA sequences in E. calamita, suggesting that the differences observed after silver staining in B. spinosus and B. viridis should be attributed to differences in chromosomal condensation and/or gene activity rather than to differences in the copy number for ribosomal genes. Regarding telomeric repeats, E. calamita is the only species with interstitial telomeric sequences (ITS) located on centromeric regions, probably originated by accumulation of telomeric sequences in the centromeric heterochromatin. Finally, we analyzed the composition and distribution of repetitive sequences by genome in situ hybridization. These experiments reveal the accumulation of repetitive sequences in centromeric regions of the three species, although these sequences are not conserved when species from different genera are compared.
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Kartavtseva IV, Sheremetyeva IN, Pavlenko MV. Intraspecies multiple chromosomal variations including rare tandem fusion in the Russian Far Eastern endemic evoron vole Alexandromysevoronensis (Rodentia, Arvicolinae). COMPARATIVE CYTOGENETICS 2021; 15:393-411. [PMID: 34900116 PMCID: PMC8629904 DOI: 10.3897/compcytogen.v15.i4.67112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/23/2021] [Indexed: 06/01/2023]
Abstract
The vole Alexandromysevoronensis (Kovalskaya et Sokolov, 1980) with its two chromosomal races, "Evoron" (2n = 38-41, NF = 54-59) and "Argi" (2n = 34, 36, 37, NF = 51-56) is the endemic vole found in the Russian Far East. For the "Argi" chromosomal race, individuals from two isolated populations in mountain regions were investigated here for the first time using GTG-, GTC-, NOR methods. In the area under study, 8 new karyotype variants have been registered. The karyotype with 2n = 34 has a rare tandem fusion of three autosomes: two biarmed (Mev6 and Mev7) and one acrocentric (Mev14) to form a large biarmed chromosome (Mev6/7/14), all of which reveal a heterozygous state. For A.evoronensis, the variation in the number of chromosomes exceeded the known estimate of 2n = 34, 36 and amounted to 2n = 34, 36, 38-41. The combination of all the variations of chromosomes for the species made it possible to describe 20 variants of the A.evoronensis karyotype, with 11 chromosomes being involved in multiple structural rearrangements. In the "Evoron" chromosomal race 4 chromosomes (Mev1, Mev4, Mev17, and Mev18) and in the "Argi" chromosomal race 9 chromosomes (Mev6, Mev7, Mev14, Mev13, Mev11, Mev15, Mev17, Mev18, and Mev19) were observed. Tandem and Robertsonian rearrangements (Mev17/18 and Mev17.18) were revealed in both chromosomal races "Evoron" and "Argi".
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Affiliation(s)
- Irina V. Kartavtseva
- Federal Scientific Center of the East Asia Terrestrial Biodiversity Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - Irina N. Sheremetyeva
- Federal Scientific Center of the East Asia Terrestrial Biodiversity Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
| | - Marina V. Pavlenko
- Federal Scientific Center of the East Asia Terrestrial Biodiversity Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690022, Russia
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Crepaldi C, Martí E, Gonçalves ÉM, Martí DA, Parise-Maltempi PP. Genomic Differences Between the Sexes in a Fish Species Seen Through Satellite DNAs. Front Genet 2021; 12:728670. [PMID: 34659353 PMCID: PMC8514694 DOI: 10.3389/fgene.2021.728670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/13/2021] [Indexed: 11/14/2022] Open
Abstract
Neotropical fishes have highly diversified karyotypic and genomic characteristics and present many diverse sex chromosome systems, with various degrees of sex chromosome differentiation. Knowledge on their sex-specific composition and evolution, however, is still limited. Satellite DNAs (satDNAs) are tandemly repeated sequences with pervasive genomic distribution and distinctive evolutionary pathways, and investigating satDNA content might shed light into how genome architecture is organized in fishes and in their sex chromosomes. The present study investigated the satellitome of Megaleporinus elongatus, a freshwater fish with a proposed Z1Z1Z2Z2/Z1W1Z2W2 multiple sex chromosome system that encompasses a highly heterochromatic and differentiated W1 chromosome. The species satellitome comprises of 140 different satDNA families, including previously isolated sequences and new families found in this study. This diversity is remarkable considering the relatively low proportion that satDNAs generally account for the M. elongatus genome (around only 5%). Differences between the sexes in regards of satDNA content were also evidenced, as these sequences are 14% more abundant in the female genome. The occurrence of sex-biased signatures of satDNA evolution in the species is tightly linked to satellite enrichment associated with W1 in females. Although both sexes share practically all satDNAs, the overall massive amplification of only a few of them accompanied the W1 differentiation. We also investigated the expansion and diversification of the two most abundant satDNAs of M. elongatus, MelSat01-36 and MelSat02-26, both highly amplified sequences in W1 and, in MelSat02-26’s case, also harbored by Z2 and W2 chromosomes. We compared their occurrences in M. elongatus and the sister species M. macrocephalus (with a standard ZW sex chromosome system) and concluded that both satDNAs have led to the formation of highly amplified arrays in both species; however, they formed species-specific organization on female-restricted sex chromosomes. Our results show how satDNA composition is highly diversified in M. elongatus, in which their accumulation is significantly contributing to W1 differentiation and not satDNA diversity per se. Also, the evolutionary behavior of these repeats may be associated with genome plasticity and satDNA variability between the sexes and between closely related species, influencing how seemingly homeologous heteromorphic sex chromosomes undergo independent satDNA evolution.
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Affiliation(s)
- Carolina Crepaldi
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências (IB), Universidade Estadual Paulista (UNESP), Rio Claro, Brazil
| | - Emiliano Martí
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências (IB), Universidade Estadual Paulista (UNESP), Rio Claro, Brazil
| | - Évelin Mariani Gonçalves
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências (IB), Universidade Estadual Paulista (UNESP), Rio Claro, Brazil
| | - Dardo Andrea Martí
- Laboratorio de Genética Evolutiva, Instituto de Biología Subtropical (IBS), Universidad Nacional de Misiones (UNaM), CONICET, Posadas, Argentina
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Kostmann A, Augstenová B, Frynta D, Kratochvíl L, Rovatsos M. Cytogenetically Elusive Sex Chromosomes in Scincoidean Lizards. Int J Mol Sci 2021; 22:ijms22168670. [PMID: 34445371 PMCID: PMC8395508 DOI: 10.3390/ijms22168670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 01/11/2023] Open
Abstract
The lizards of the species-rich clade Scincoidea including cordylids, gerrhosaurids, skinks, and xantusiids, show an almost cosmopolitan geographical distribution and a remarkable ecological and morphological divergence. However, previous studies revealed limited variability in cytogenetic traits. The sex determination mode was revealed only in a handful of gerrhosaurid, skink, and xantusiid species, which demonstrated either ZZ/ZW or XX/XY sex chromosomes. In this study, we explored the karyotypes of six species of skinks, two species of cordylids, and one gerrhosaurid. We applied conventional and molecular cytogenetic methods, including C-banding, fluorescence in situ hybridization with probes specific for telomeric motifs and rDNA loci, and comparative genomic hybridization. The diploid chromosome numbers are rather conserved among these species, but the chromosome morphology, the presence of interstitial telomeric sequences, and the topology of rDNA loci vary significantly. Notably, XX/XY sex chromosomes were identified only in Tiliqua scincoides, where, in contrast to the X chromosome, the Y chromosome lacks accumulations of rDNA loci. We confirm that within the lizards of the scincoidean clade, sex chromosomes remained in a generally poor stage of differentiation.
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Affiliation(s)
- Alexander Kostmann
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
| | - Barbora Augstenová
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
| | - Daniel Frynta
- Department of Zoology, Faculty of Science, Charles University, 12844 Prague, Czech Republic;
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, 12844 Prague, Czech Republic; (A.K.); (B.A.); (L.K.)
- Correspondence:
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Augstenová B, Pensabene E, Kratochvíl L, Rovatsos M. Cytogenetic Evidence for Sex Chromosomes and Karyotype Evolution in Anguimorphan Lizards. Cells 2021; 10:cells10071612. [PMID: 34203198 PMCID: PMC8304200 DOI: 10.3390/cells10071612] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/27/2022] Open
Abstract
Anguimorphan lizards are a morphologically variable group of squamate reptiles with a wide geographical distribution. In spite of their importance, they have been cytogenetically understudied. Here, we present the results of the cytogenetic examination of 23 species from five anguimorphan families (Anguidae, Helodermatidae, Shinisauridae, Varanidae and Xenosauridae). We applied both conventional (Giemsa staining and C-banding) and molecular cytogenetic methods (fluorescence in situ hybridization with probes for the telomeric motifs and rDNA loci, comparative genome hybridization), intending to describe the karyotypes of previously unstudied species, to uncover the sex determination mode, and to reveal the distribution of variability in cytogenetic characteristics among anguimorphan lizards. We documented that karyotypes are generally quite variable across anguimorphan lineages, with anguids being the most varying. However, the derived chromosome number of 2n = 40 exhibits a notable long-term evolutionary stasis in monitors. Differentiated ZZ/ZW sex chromosomes were documented in monitors and helodermatids, as well as in the anguids Abronia lythrochila, and preliminary also in Celestus warreni and Gerrhonotus liocephalus. Several other anguimorphan species have likely poorly differentiated sex chromosomes, which cannot be detected by the applied cytogenetic methods, although the presence of environmental sex determination cannot be excluded. In addition, we uncovered a rare case of spontaneous triploidy in a fully grown Varanus primordius.
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