Latest Articles from Comparative Cytogenetics Latest 18 Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Thu, 28 Mar 2024 20:56:38 +0200 Pensoft FeedCreator https://compcytogen.pensoft.net/i/logo.jpg Latest Articles from Comparative Cytogenetics https://compcytogen.pensoft.net/ Cell culture and karyotypic description of Pseudophryne coriacea (Keferstein, 1868) (Amphibia, Anura) from the New South Wales Central Coast https://compcytogen.pensoft.net/article/113526/ Comparative Cytogenetics 17: 263-272

DOI: 10.3897/compcytogen.17.113526

Authors: Richard Mollard, Michael Mahony

Abstract: The karyotype of the IUCN least concern red-backed toadlet Pseudophryne (P.) coriacea (Keferstein, 1868) from the New South Wales Central Coast is described following tissue culture of toe clipping macerates and conventional DAPI staining. The diploid number is 2n = 24. The karyotype is represented by six large and five small chromosomal pairs and one very small chromosomal pair. The very small chromosome 12 is 12% the size of chromosome 1. One of the large chromosomes is subtelocentric, two of the large chromosomes are submetacentric and the remaining chromosomes are metacentric. The putative nucleolus organiser region (NOR) is observed on chromosome 4. The diploid number and location of the putative NOR correlates to that of the previously published IUCN critically endangered P. corroboree (Moore 1953) and unpublished descriptions of the P. coriacea karyotype. This is the first described cell culture of a species from the genus Pseudophryne Fitzinger, 1843, first published analysis of the P. coriacea karyotype and the first published analysis of centromeric allocation of this genus. Globally there exists a large inventory of tissue samples in cryobanks that are not associated with known recovery mechanisms such as basic cell culture techniques. Detailed cytogenetic analyses of these cryobanked samples are therefore not possible. This work therefore enables: (i) a comparison of the P. coriacea karyotype with that of the critically endangered P. corroboree and (ii) a benchmark for repeat and future cytogenetic and genomic analyses of cryostored samples of this genus.

HTML

XML

PDF

]]>
Short Communication Fri, 10 Nov 2023 10:41:07 +0200
First karyotype description of the species of Adenomera Steindachner, 1867 (Anura, Leptodactylidae) in the “ thomei” clade https://compcytogen.pensoft.net/article/82641/ Comparative Cytogenetics 16(3): 151-159

DOI: 10.3897/compcytogen.v16.i3.82641

Authors: Ramon Costa Dominato, Guilherme Costa de Oliveira, Carla Santana Cassini, Victor Goyannes Dill Orrico, Cléa dos Santos Ferreira Mariano, Janisete Gomes Silva

Abstract: The genus Adenomera Steindachner, 1867 currently comprises 29 nominal species, some of which are suggested to be cryptic species complexes. The present study was carried out with specimens of the “thomei” clade that encompasses three taxa distributed in the Atlantic Forest biome: Adenomera thomei Almeida et Angulo, 2006, Adenomera sp. L., and Adenomera sp. M. We used classical cytogenetics to describe the diploid number and karyomorphology of these three species collected in two different locations in the state of Bahia, Brazil. Our results revealed the diploid number 2n = 24 (FN = 34) with two pairs of metacentric chromosomes (pairs 1 and 5), three pairs of submetacentric chromosomes (pairs 2, 3, and 4), and seven pairs of telocentric chromosomes (pairs 6, 7, 8, 9, 10, 11, and 12). Further morphological, bioacoustic, and cytogenetic data (C-banding and AgNor) are needed to better delineate the lineages within the “thomei” clade.

HTML

XML

PDF

]]>
Short Communication Tue, 30 Aug 2022 12:58:41 +0300
Comparative cytogenetics on eight Malagasy Mantellinae (Anura, Mantellidae) and a synthesis of the karyological data on the subfamily https://compcytogen.pensoft.net/article/76260/ Comparative Cytogenetics 16(1): 1-17

DOI: 10.3897/compcytogen.v16.i1.76260

Authors: Marcello Mezzasalma, Franco Andreone, Gaetano Odierna, Fabio Maria Guarino, Angelica Crottini

Abstract: We performed a molecular and cytogenetic analysis on different Mantellinae species and revised the available chromosomal data on this group to provide an updated assessment of its karyological diversity and evolution. Using a fragment of the mitochondrial 16S rRNA, we performed a molecular taxonomic identification of the samples that were used for cytogenetic analyses. A comparative cytogenetic analysis, with Giemsa’s staining, Ag-NOR staining and sequential C-banding + Giemsa + CMA + DAPI was performed on eight species: Gephyromantis sp. Ca19, G. striatus (Vences, Glaw, Andreone, Jesu et Schimmenti, 2002), Mantidactylus (Chonomantis) sp. Ca11, M. (Brygoomantis) alutus (Peracca, 1893), M. (Hylobatrachus) cowanii (Boulenger, 1882), Spinomantis prope aglavei “North” (Methuen et Hewitt, 1913), S. phantasticus (Glaw et Vences, 1997) and S. sp. Ca3. Gephyromantis striatus, M. (Brygoomantis) alutus and Spinomantis prope aglavei “North” have a karyotype of 2n = 24 chromosomes while the other species show 2n = 26 chromosomes. Among the analysed species we detected differences in the number and position of telocentric elements, location of NOR loci (alternatively on the 6th, 7th or 10th pair) and in the distribution of heterochromatin, which shows species-specific patterns. Merging our data with those previously available, we propose a karyotype of 2n = 26 with all biarmed elements and loci of NORs on the 6th chromosome pair as the ancestral state in the whole family Mantellidae. From this putative ancestral condition, a reduction of chromosome number through similar tandem fusions (from 2n = 26 to 2n = 24) occurred independently in Mantidactylus Boulenger, 1895 (subgenus Brygoomantis Dubois, 1992), Spinomantis Dubois, 1992 and Gephyromantis Methuen, 1920. Similarly, a relocation of NORs, from the putative primitive configuration on the 6th chromosome, occurred independently in Gephyromantis, Blommersia Dubois, 1992, Guibemantis Dubois, 1992, Mantella Boulenger, 1882 and Spinomantis. Chromosome inversions of primitive biarmed elements likely generated a variable number of telocentric elements in Mantella nigricans Guibé, 1978 and a different number of taxa of Gephyromantis (subgenera Duboimantis Glaw et Vences, 2006 and Laurentomantis Dubois, 1980) and Mantidactylus (subgenera Brygoomantis, Chonomantis Glaw et Vences, 1994, Hylobatrachus Laurent, 1943 and Ochthomantis Glaw et Vences, 1994).

HTML

XML

PDF

]]>
Research Article Fri, 11 Feb 2022 16:28:42 +0200
Comparative cytogenetics of the ground frogs Eupsophus emiliopugini Formas, 1989 and E. vertebralis Grandison, 1961 (Alsodidae) with comments on their inter- and intraspecific chromosome differentiation https://compcytogen.pensoft.net/article/46852/ Comparative Cytogenetics 14(1): 61-74

DOI: 10.3897/CompCytogen.v14i1.46852

Authors: Camila A. Quercia, Elkin Y. Suárez-Villota, Fausto Foresti, José J. Nuñez

Abstract: South American frogs of the genus Eupsophus Fitzinger, 1843 comprise 10 species. Two of them, Eupsophus vertebralis Grandison, 1961 and E. emiliopugini Formas, 1989 belong to the Eupsophus vertebralis group, exhibiting 2n = 28. Fundamental number differences between these species have been described using conventional chromosome staining of few specimens from only two localities. Here, classical techniques (Giemsa, C-banding, CMA3/DAPI banding, and Ag-NOR staining), and fluorescence in situ hybridization (FISH, with telomeric and 28S ribosomal probes), were applied on individuals of both species collected from 15 localities. We corroborate differences in fundamental numbers (FN) between E. vertebralis and E. emiliopugini through Giemsa staining and C-banding (FN = 54 and 56, respectively). No interstitial fluorescent signals, but clearly stained telomeric regions were detected by FISH using telomeric probe over spreads from both species. FISH with 28S rDNA probes and Ag-NOR staining confirmed the active nucleolus organizer regions signal on pair 5 for both species. Nevertheless, one E. emiliopugini individual from the Puyehue locality exhibited 28S ribosomal signals on pairs 4 and 5. Interestingly, only one chromosome of each pair showed Ag-NOR positive signals, showing a nucleolar dominance pattern. Chromosomal rearrangements, rRNA gene dosage control, mobile NORs elements, and/or species hybridization process could be involved in this interpopulation chromosomal variation.

HTML

XML

PDF

]]>
Research Article Mon, 27 Jan 2020 21:32:00 +0200
Recurrent variation in the active NOR sites in the monkey frogs of the genus Pithecopus Cope, 1866 (Phyllomedusidae, Anura) https://compcytogen.pensoft.net/article/37687/ Comparative Cytogenetics 13(4): 325-338

DOI: 10.3897/CompCytogen.v13i4.37687

Authors: Joana Moura Gama, Camilla Borges Gazolla, Deborah Yasmin de Souza, Shirlei Maria Recco-Pimentel, Daniel Pacheco Bruschi

Abstract: Treefrogs of the genus Pithecopus Cope, 1866 exhibit expressive chromosomal homogeneity which contrasts with a high variation frequency of the nucleolus organizer region (NOR) related to the group. Currently, the genus contains eleven species and no chromosomal data are available on P. palliatus Peters, 1873, P. ayeaye Lutz, 1966 and P. megacephalus Miranda-Ribeiro, 1926. Here, we describe the karyotypes of these three species based on Giemsa staining, C-banding, silver impregnation and in situ hybridization (FISH). We were also analyze the evolutionary dynamic of the NOR-bearing chromosome in species of genus under a phylogenetic view. The results indicate that P. palliatus, P. ayeaye, and P. megacephalus have similar karyotypes, which are typical of the genus Pithecopus. In P. palliatus the NOR was detected in the pericentromeric region of pair 9p whereas in P. ayeaye and P. megacephalus we report cases of the multiple NOR sites in karyotypes. In P. ayeaye the NOR was detected in the pericentromeric region of pair 9p in both homologues and additional sites was detected in pairs 3q, 4p, and 8q, all confirmed by FISH experiments. Already in P. megacephalus the NOR sites were detected in pericentromeric region homologues of pair 8q and additionally in one chromosome of pair 13q. A comparative overview of all the Pithecopus karyotypes analyzed up to now indicates the recurrence of the NOR-bearing chromosome pairs and the position of the NORs sites on these chromosomes. We hypothesized that this feature is a result of a polymorphic condition present in the common ancestor of Pithecopus. In such case, the lineages derived from polymorphic ancestor have reached fixation independently after divergence of lineages, resulting in a high level of homoplasy observed in this marker. Our findings help to fill the gaps in the understanding of the karyotype of the genus Pithecopus and reinforce the role of the evolutionary dynamics of the rDNA genes in karyotype diversification in this group.

HTML

XML

PDF

]]>
Research Article Mon, 21 Oct 2019 16:04:42 +0300
Chromosome spreading of the (TTAGGG)n repeats in the Pipa carvalhoi Miranda-Ribeiro, 1937 (Pipidae, Anura) karyotype https://compcytogen.pensoft.net/article/35524/ Comparative Cytogenetics 13(3): 297-309

DOI: 10.3897/CompCytogen.v13i3.35524

Authors: Michelle Louise Zattera, Luana Lima, Iraine Duarte, Deborah Yasmin de Sousa, Olívia Gabriela dos Santos Araújo, Thiago Gazoni, Tamí Mott, Shirlei Maria Recco-Pimentel, Daniel Pacheco Bruschi

Abstract: Pipidae is a clade of Anura that diverged relatively early from other frogs in the phylogeny of the group. Pipids have a unique combination of morphological features, some of which appear to represent a mix of adaptations to aquatic life and plesiomorphic characters of Anura. The present study describes the karyotype of Pipa carvalhoi Miranda-Ribeiro, 1937, including morphology, heterochromatin distribution, and location of the NOR site. The diploid number of P. carvalhoi is 2n=20, including three metacentric pairs (1, 4, 8), two submetacentric (2 and 7), three subtelocentric (3, 5, 6), and two telocentric pairs (9 and 10). C-banding detected centromeric blocks of heterochromatin in all chromosome pairs and the NOR detected in chromosome pair 9, as confirmed by FISH using the rDNA 28S probe. The telomeric probes indicated the presence of interstitial telomeric sequences (ITSs), primarily in the centromeric region of the chromosomes, frequently associated with heterochromatin, suggesting that these repeats are a significant component of this region. The findings of the present study provide important insights for the understanding of the mechanisms of chromosomal evolution in the genus Pipa, and the diversification of the Pipidae as a whole.

HTML

XML

PDF

]]>
Research Article Mon, 14 Oct 2019 17:57:14 +0300
Variability of NOR patterns in European water frogs of different genome composition and ploidy level https://compcytogen.pensoft.net/article/10804/ Comparative Cytogenetics 11(2): 249-266

DOI: 10.3897/CompCytogen.v11i2.10804

Authors: Anna Zaleśna, Maria Florek, Mariusz Rybacki, Maria Ogielska

Abstract: We studied water frogs from a complex composed of two species: Pelophylax lessonae (Camerano, 1882) (genome LL, 2n = 26) and P. ridibundus (Pallas, 1771) (RR, 2 = 26), and their natural hybrid P. esculentus (Fitzinger, 1843) of various ploidy and genome composition (RL, 2n = 26, and RRL or RLL, 3n = 39). Tetraploids RRLL were found (4n = 52) in juveniles. We applied cytogenetic techniques: AgNO3, chromomycin A3, PI and fluorescent in situ hybridization with a 28S rDNA probe. Results obtained by silver staining corresponded well with those stained with CMA3, PI and FISH. As a rule, NORs are situated on chromosomes 10. The number of Ag-NORs visible on metaphase plates was the same as the number of Ag-nucleoli present in interphase nuclei of the same individual. In all analyzed metaphases, NORs exhibited variations in size after AgNO3 and CMA3 stainings. Sixty-six individuals (out of 407 analyzed) were polymorphic for the localization and number of NORs. Fifty-one diploids had NORs only on one chromosome of pair 10. Three triploids (LLR and RRL) displayed two NORs, and two other triploid RRL individuals displayed one, instead of expected three NORs. In ten individuals extra NORs were detected on chromosomes other than 10 (chromosomes 2 and 9).

HTML

XML

PDF

]]>
Research Article Tue, 18 Apr 2017 14:22:30 +0300
Comparative analysis based on replication banding reveals the mechanism responsible for the difference in the karyotype constitution of treefrogs Ololygon and Scinax (Arboranae, Hylidae, Scinaxinae) https://compcytogen.pensoft.net/article/11254/ Comparative Cytogenetics 11(2): 267-283

DOI: 10.3897/CompCytogen.v11i2.11254

Authors: Simone Lilian Gruber, Gabriela Isabela Gomes de Oliveira, Ana Paula Zampieri Silva, Hideki Narimatsu, Célio Fernando Baptista Haddad, Sanae Kasahara

Abstract: According to the recent taxonomic and phylogenetic revision of the family Hylidae, species of the former Scinax catharinae (Boulenger, 1888) clade were included in the resurrected genus Ololygon Fitzinger, 1843, while species of the Scinax ruber (Laurenti, 1768) clade were mostly included in the genus Scinax Wagler, 1830, and two were allocated to the newly created genus Julianus Duellman et al., 2016. Although all the species of the former Scinax genus shared a diploid number of 2n = 24 and the same fundamental number of chromosome arms of FN = 48, two karyotypic constitutions were unequivocally recognized, related mainly to the distinct size and morphology of the first two chromosome pairs. Some possible mechanisms for these differences had been suggested, but without any experimental evidence. In this paper, a comparison was carried out based on replication chromosome banding, obtained after DNA incorporation of 5-bromodeoxiuridine in chromosomes of Ololygon and Scinax. The obtained results revealed that the loss of repetitive segments in chromosome pairs 1 and 2 was the mechanism responsible for karyotype difference. The distinct localization of the nucleolus organizer regions in the species of both genera also differentiates the two karyotypic constitutions.

HTML

XML

PDF

]]>
Research Article Tue, 18 Apr 2017 14:21:55 +0300
Comparative cytogenetics of tree frogs of the Dendropsophus marmoratus (Laurenti, 1768) group: conserved karyotypes and interstitial telomeric sequences https://compcytogen.pensoft.net/article/9972/ Comparative Cytogenetics 10(4): 753-767

DOI: 10.3897/CompCytogen.v10i4.9972

Authors: Lívia S.R. Teixeira, Karin Regina Seger, Cíntia Pelegrineti Targueta, Victor G. Dill Orrico, Luciana Bolsoni Lourenço

Abstract: The diploid number 2n = 30 is a presumed synapomorphy of Dendropsophus Fitzinger, 1843, although a noticeable variation in the number of biarmed/telocentric chromosomes is observed in this genus. Such a variation suggests that several chromosomal rearrangements took place after the evolutionary origin of the hypothetical ancestral 30-chromosome karyotype; however, the inferred rearrangements remain unknown. Distinct numbers of telocentric chromosomes are found in the two most cytogenetically studied species groups of Dendropsophus. In contrast, all three species of the Dendropsophus marmoratus (Laurenti, 1768) group that are already karyotyped presented five pairs of telocentric chromosomes. In this study, we analyzed cytogenetically three additional species of this group to investigate if the number of telocentric chromosomes in this group is not as variable as in other Dendropsophus groups. We described the karyotypes of Dendropsophus seniculus (Cope, 1868), D. soaresi (Caramaschi & Jim, 1983) and D. novaisi (Bokermann, 1968) based on Giemsa staining, C-banding, silver impregnation and in situ hybridization with telomeric probes. Dendropsophus seniculus, D. soaresi and D. novaisi presented five pairs of telocentric chromosomes, as did the remaining species of the group previously karyotyped. Though the species of this group show a high degree of karyotypic similarity, D. soaresi was unique in presenting large blocks of het-ITSs (heterochromatic internal telomeric sequences) in the majority of the centromeres. Although the ITSs have been interpreted as evidence of ancestral chromosomal fusions and inversions, the het-ITSs detected in the karyotype of D. soaresi could not be explained as direct remnants of ancestral chromosomal rearrangements because no evidence of chromosomal changes emerged from the comparison of the karyotypes of all of the species of the D. marmoratus group.

HTML

XML

PDF

]]>
Research Article Wed, 14 Dec 2016 18:56:43 +0200
Karyological study of Ololygon tripui (Lourenço, Nascimento and Pires, 2009), (Anura, Hylidae) with comments on chromosomal traits among populations https://compcytogen.pensoft.net/article/9176/ Comparative Cytogenetics 10(4): 505-516

DOI: 10.3897/CompCytogen.v10i4.9176

Authors: Marco Antônio A. Peixoto, Marina P.C. Oliveira, Renato N. Feio, Jorge A. Dergam

Abstract: To increase the number of cytogenetic characters used in Ololygon tripui systematics, we applied some cytogenetic techniques such as Giemsa, C- and NOR-banding, and fluorescence in situ hybridization (FISH) with 18S rDNA and repetitive microsatellite DNA probes to the study of four populations from Minas Gerais State (southeastern Brazil). All populations showed 2n = 24 and FN = 48, and chromosomal formula 8m + 10sm + 6st. Nucleolar organizing regions (NORs) were located on chromosome pair 6 in all populations, although in the Tripuí locality additional markings were observed on one homologue of chromosome pair 3. These patterns were partially congruent with results obtained using the 18S rDNA FISH probe. The microsatellites repetitive DNA (GA)15 and (CAT)10 probes accumulated predominantly in the terminal region of all chromosomes. Chromosome morphology and Ag-NOR were conserved among populations, a conserved pattern in Ololygon Fitzinger, 1843. Repetitive DNA FISH probes patterns were similar among populations, but they revealed species-specific differences when compared with other species of the genus Ololygon, suggesting that molecular cytogenetics are potentially more informative in karyologically conservative taxa.

HTML

XML

PDF

]]>
Research Article Mon, 10 Oct 2016 15:35:12 +0300
Chromosomal analysis of Physalaemus kroyeri and Physalaemus cicada (Anura, Leptodactylidae) https://compcytogen.pensoft.net/article/9319/ Comparative Cytogenetics 10(2): 311-323

DOI: 10.3897/CompCytogen.v10i2.9319

Authors: Stenio Eder Vittorazzi, Luciana Bolsoni Lourenço, Mirco Solé, Renato Gomes Faria, Shirlei Maria Recco-Pimentel

Abstract: All the species of Physalaemus Fitzinger, 1826 karyotyped up until now have been classified as 2n = 22. The species of the P. cuvieri group analyzed by C-banding present a block of heterochromatin in the interstitial region of the short arm of pair 5. Physalaemus cicada Bokermann, 1966 has been considered to be a member of the P. cuvieri species group, although its interspecific phylogenetic relationships remain unknown. The PcP190 satellite DNA has been mapped on the chromosomes of most of the species of the P. cuvieri group. For two species, P. cicada and P. kroyeri (Reinhardt & Lütken, 1862), however, only the chromosome number and morphology are known. Given this, the objective of the present study was to analyze the chromosomes of P. cicada and P. kroyeri, primarily by C-banding and PcP190 mapping. The results indicate that P. kroyeri and P. cicada have similar karyotypes, which were typical of Physalaemus. In both species, the NORs are located on the long arm of pair 8, and the C-banding indicated that, among other features, P. kroyeri has the interstitial band on chromosome 5, which is however absent in P. cicada. Even so, a number of telomeric bands were observed in P. cicada. The mapping of the PcP190 satellite DNA highlighted areas of the centromeric region of the chromosomes of pair 1 in both species, although in P. kroyeri, heteromorphism was also observed in pair 3. The cytogenetic evidence does not support the inclusion of P. cicada in the P. cuvieri group. In the case of P. kroyeri, the interstitial band on pair 5 is consistent with the existence of a cytogenetic synapomorphy in the P. cuvieri species group.

HTML

XML

PDF

]]>
Research Article Fri, 8 Jul 2016 10:36:31 +0300
Cytogenetic characterization and B chromosome diversity in direct-developing frogs of the genus Oreobates (Brachycephaloidea, Craugastoridae) https://compcytogen.pensoft.net/article/5718/ Comparative Cytogenetics 10(1): 141-156

DOI: 10.3897/CompCytogen.v10i1.5718

Authors: Juan Martín Ferro, Alberto Taffarel, Darío Cardozo, Jimena Grosso, María Pía Puig, Pablo Suárez, Mauricio Sebastián Akmentins, Diego Baldo

Abstract: Oreobates Jiménez de la Espada, 1872 is a large group of South American frogs with terrestrial reproduction and direct development, located in the superfamily Brachycephaloidea. About 260 brachycephaloidean species have been cytogenetically studied so far, at least with standard techniques. However, this information represents fewer than 17% species of the family Craugastoridae Hedges, Duellman & Heinicke, 2008, where the genus Oreobates is included. In the present work, using a diversity of standard and molecular techniques, we describe the karyotype of O. barituensis Vaira & Ferrari, 2008, O. berdemenos Pereyra, Cardozo, Baldo & Baldo, 2014 and O. discoidalis (Peracca, 1895), from northwestern Argentina. The three species analyzed showed a diploid karyotype with 2n = 22 biarmed chromosomes, fundamental number (FN) = 44, nucleolus organizer regions (NORs) located pericentromerically on pair 7, and a centromeric and pericentromeric C-banding pattern. We observed variations in the chromosome number in O. barituensis due the presence of two morphs of B chromosomes, one medium-sized telocentric (BT) and another subtelocentric and smaller (Bst). Both B chromosomes are mitotically stable and were recorded in all somatic and germinal cells analyzed. The BT chromosome occurred at a maximum of one per individual (2n = 22+BT), and the other one was observed single (2n = 22 + Bst) or as a pair in two doses (2n = 22 + 2BT). We additionally observed other supernumerary chromosomes in the three species analyzed, all of them euchromatic, small, dot-shaped and with instability during mitoses, showing a frequency of occurrence below 50% in studied specimens. The occurrence of polymorphic and spontaneous chromosomal rearrangements and supernumerary chromosomes is a recurrent feature reported in frogs with terrestrial habits (Brachycephaloidea and Hemiphractidae Peters, 1862), which suggests that Brachycephaloidea may be a promising group for studying the origin and maintenance of B chromosomes in anurans.

HTML

XML

PDF

]]>
Research Article Mon, 21 Mar 2016 10:51:42 +0200
Cytogenetic analysis of Scinax auratus and Scinax eurydice (Anura, Hylidae) with emphasis on cytotaxonomy https://compcytogen.pensoft.net/article/4593/ Comparative Cytogenetics 9(2): 227-236

DOI: 10.3897/CompCytogen.v9i2.4593

Authors: Lidia Nogueira, Fabilene Paim, Débora Diniz, Mirco Sole, Paulo Roberto Affonso, Sérgio Siqueira, Iracilda Sampaio

Abstract: Scinax Wagler, 1830 is a species-rich genus of amphibians with relatively few detailed chromosomal reports. In this work, cytogenetic analyses of Scinax auratus (Wied-Neuwied, 1821) and Scinax eurydice (Bokermann, 1968) were carried out based on conventional (Giemsa staining, Ag-NOR and C-banding) and cytomolecular (base-specific fluorochrome staining and fluorescence in situ hybridization – FISH of ribosomal probes) techniques. Both species shared the same karyotype, location of active nucleolar organizer regions on pair 11 and GC-rich heterochromatin, as reported for most species in S. ruber clade. Interpopulation chromosomal variation was observed in S. eurydice, indicating the occurrence of cryptic species. The mapping of 18S ribosomal genes by FISH is reported for the first time in both species.

HTML

XML

PDF

]]>
Short Communication Tue, 26 May 2015 11:51:02 +0300
Possible interspecific origin of the B chromosome of Hypsiboas albopunctatus (Spix, 1824) (Anura, Hylidae), revealed by microdissection, chromosome painting, and reverse hybridisation https://compcytogen.pensoft.net/article/1819/ Comparative Cytogenetics 8(3): 185-197

DOI: 10.3897/compcytogen.v8i3.7771

Authors: Simone Gruber, Débora Diniz, Patrícia Sobrinho-Scudeler, Fausto Foresti, Celio Haddad, Sanae Kasahara

Abstract: The B chromosome in the hylid Hypsiboas albopunctatus (2n = 22 + B) is small, almost entirely composed of C-positive heterochromatin, and does not pair with any chromosome of the A complement. B probe, obtained by microdissection and DOP-PCR amplification, was used to search for homology between the B and regular chromosomes of H. albopunctatus and of the related species H. raniceps (Cope, 1862). Reverse hybridisation was also carried out in the investigation. The B probe exclusively painted the supernumerary, not hybridising any other chromosomes in H. albopunctatus, but all H. raniceps chromosomes showed small labelling signals. This result might be an indication that differences exist between the repetitive sequences of A and B chromosomes of H. albopunctatus, and that the chromosomes of H. raniceps and the heterochromatin of the B chromosome of H. albopunctatus are enriched with the same type of repetitive DNA. In meiotic preparations, the B labelled about 30% of scored spermatids, revealing a non-mendelian inheritance, and the painted B in micronucleus suggests that the supernumerary is eliminated from germ line cells. Although our results could suggest an interespecific origin of the B at first sight, further analysis on its repetitive sequences is still necessary. Nevertheless, the accumulation of repetitive sequences, detected in another species, even though closely related, remains an intriguing question.

HTML

XML

PDF

]]>
Research Article Fri, 8 Aug 2014 00:00:00 +0300
Comparative cytogenetics of Physalaemus albifrons and Physalaemus cuvieri species groups (Anura, Leptodactylidae) https://compcytogen.pensoft.net/article/1812/ Comparative Cytogenetics 8(2): 103-123

DOI: 10.3897/compcytogen.v8i2.6414

Authors: Stenio Vittorazzi, Yeda Quinderé, Shirlei Recco-Pimentel, Cristian Tomatis, Diego Baldo, Janaina Reis, Juan Ferro, Jucivaldo Lima, Luciana Lourenço

Abstract: Recently, Physalaemus albifrons (Spix, 1824) was relocated from the P. cuvieri group to the same group as P. biligonigerus (Cope, 1861), P. marmoratus (Reinhardt & Lütken, 1862) and P. santafecinus Barrio, 1965. To contribute to the analysis of this proposition, we studied the karyotypes of P. albifrons, P. santafecinus and three species of the P. cuvieri group. The karyotype of P. santafecinus was found to be very similar to those of P. biligonigerus and P. marmoratus, which were previously described. A remarkable characteristic that these three species share is a conspicuous C-band that extends from the pericentromeric region almost to the telomere in the short arm of chromosome 3. This characteristic is not present in the P. albifrons karyotype and could be a synapomorphy of P. biligonigerus, P. marmoratus and P. santafecinus. The karyotype of P. santafecinus is also similar to those of P. marmoratus and P. biligonigerus owing to the presence of several terminal C-bands and the distal localization of the NOR in a small metacentric chromosome. In contrast, the P. albifrons karyotype has no terminal C-bands and its NOR is located interstitially in the long arm of submetacentric chromosome 8. The NOR-bearing chromosome of P. albifrons very closely resembles those found in P. albonotatus (Steindachner, 1864), P. cuqui Lobo, 1993 and some populations of P. cuvieri Fitzinger, 1826. Additionally, the P. albifrons karyotype has an interstitial C-band in chromosome 5 that has been exclusively observed in species of the P. cuvieri group. Therefore, we were not able to identify any chromosomal feature that supports the reallocation of P. albifrons.

HTML

XML

PDF

]]>
Research Article Fri, 16 May 2014 00:00:00 +0300
Chromosomal homology of Uraeotyphlus oxyurus group of species (Amphibia, Gymnophiona, Ichthyophiidae) https://compcytogen.pensoft.net/article/1785/ Comparative Cytogenetics 7(1): 11-23

DOI: 10.3897/compcytogen.v7i1.3603

Authors: Venu Govindappa, G Venkatachalaiah

Abstract: Uraeotyphlus oxyurus (Dumeril et Bibron, 1841), U. interruptus Pillai et Ravichandran, 1999, U. narayani Seshachar, 1939 and U. menoni Annandale, 1913 were cytogenetically analysed following conventional and differential staining techniques. These species show similar karyotypes with 2n=36 (FN=58). There were no traces of species-specific features in regard to C-banding and NOR staining. The comparative study of karyotypes shows chromosomal homologies among the four species. Chromosomal data seem to support the concept that two species groups exist in the genus Uraeotyphlus.

HTML

XML

PDF

]]>
Research Article Mon, 18 Mar 2013 00:00:00 +0200
Karyotype analysis of seven species of the tribe Lophiohylini (Hylinae, Hylidae, Anura), with conventional and molecular cytogenetic techniques https://compcytogen.pensoft.net/article/1770/ Comparative Cytogenetics 6(4): 409-423

DOI: 10.3897/compcytogen.v6i4.3945

Authors: Simone Gruber, Celio Haddad, Sanae Kasahara

Abstract: Few species of the tribe Lophiohylini have been karyotyped so far, and earlier analyses were performed mainly with standard staining. Based on the analysis of seven species with use of routine banding and molecular cytogenetic techniques, the karyotypes were compared and the cytogenetic data were evaluated in the light of the current phylogenies. A karyotype with 2n = 24 and NOR in the chromosome 10 detected by Ag-impregnation and FISH with an rDNA probe was shared by Aparasphenodon bokermanni Miranda-Ribeiro, 1920, Itapotihyla langsdorffii (Duméril and Bibron, 1841), Trachycephalus sp., T. mesophaeus (Hensel, 1867), and T. typhonius (Linnaeus, 1758). Phyllodytes edelmoi Peixoto, Caramaschi et Freire, 2003 and P. luteolus (Wied-Neuwied, 1824) had reduced the diploid number from 2n = 24 to 2n = 22 with one of the small-sized pairs clearly missing, and NOR in the large chromosome 2, but the karyotypes were distinct regarding the morphology of chromosome pairs 4 and 6. Based on the cytogenetic and phylogenetic data, it was presumed that the chromosome evolution occurred from an ancestral type with 2n = 24, in which a small chromosome had been translocated to one or more unidentified chromosomes. Whichever hypothesis is more probable, other rearrangements should have occurred later, to explain the karyotype differences between the two species of Phyllodytes Wagler, 1830. The majority of the species presented a small amount of centromeric C-banded heterochromatin and these regions were GC-rich. The FISH technique using a telomeric probe identified the chromosome ends and possibly (TTAGGG)n-like sequences in the repetitive DNA out of the telomeres in I. langsdorffii and P. edelmoi. The data herein obtained represent an important contribution for characterizing the karyotype variability within the tribe Lophiohylini scarcely analysed so far.

HTML

XML

PDF

]]>
Research Article Mon, 3 Dec 2012 00:00:00 +0200
Features of the karyotypes of Pelophylax ridibundus Pallas, 1771 and Rana macrocnemis Boulenger, 1885 (Amphibia: Ranidae) from Armenia https://compcytogen.pensoft.net/article/1671/ Comparative Cytogenetics 3(1): 11-24

DOI: 10.3897/compcytogen.v3i1.4

Authors: A Martirosyan, Ilona Stepanyan

Abstract: Сhromosomal complements of Pelophylax ridibundus Pallas, 1771 from 9 localities (Northern, Central and South Armenia) and Rana macrocnemis Boulenger, 1885 from one locality (North-West Armenia) have been analyzed. The chromosome sets of P. ridibundus collected from 8 localities showed 2n=26, (10m+12sm+4st; NF=52). A secondary constriction has been observed in all studied individuals on the 10-th chromosome pair showing NOR-positive reaction. C-positive heterochromatin blocks have been observed on long arms of the 2-nd and 10-th pairs of chromosomes (7 localities). In addition, C-heterochromatin blocks have been found on interstitial regions of short arms of the 12-th pairs, as well as in telomeric regions of long arms of the 9-th pairs and on short arms of the 5-th pair in the frogs from 2 localities. The karyotype of P. ridibundus from populations near Ejmiatsin differs from other populations (2n=26, 12m+10sm+4st). Diploid number of chromosomes of R. macrocnemis was also 26 (8m+12sm+6st, NF=52). Blocks of C-positive heterochromatin have been revealed in telomeric parts of the 1-st, 2-nd (p), 3-rd (q), 4-th (q), 6-th, 9-th (p), 10-th (p,q) and 13-th (q) pairs, as well as in interstitial regions of the 1-st and 2-nd pairs of chromosomes. Intrapopulation and interpopulation geographic variations of karyotypes and C-heterochromatin banding patterns of P. ridibundus have been revealed. Karyotypically, morphotypes “macrocnemis” and “camerani” are closely related.

HTML

PDF

]]>
Research Article Thu, 6 Aug 2009 00:00:00 +0300