scholarly journals Chromosome analysis in Saccodon wagneri (Characiformes) and insights into the karyotype evolution of Parodontidae

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Mauro Nirchio ◽  
Maria Cecilia Masache ◽  
Fabilene Gomes Paim ◽  
Marcelo de Bello Cioffi ◽  
Orlando Moreira Filho ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
5S Rdna ◽  
Chromosome Analysis ◽  
Valid Species ◽  
Z Chromosome ◽  
Rdna Genes ◽  
Heteromorphic Sex Chromosomes ◽  
Karyotype Structure ◽  
Interstitial Telomeric Sites

ABSTRACT Parodontidae is a relatively small group of Neotropical characiform fishes consisting of three genera (Apareiodon, Parodon, and Saccodon) with 32 valid species. A vast cytogenetic literature is available on Apareiodon and Parodon, but to date, there is no cytogenetic data about Saccodon, a genus that contains only three species with a trans-Andean distribution. In the present study the karyotype of S. wagneri was described, based on both conventional (Giemsa staining, Ag-NOR, C-bands) and molecular (repetitive DNA mapping by fluorescent in situ hybridization) methods. A diploid chromosome number of 2n = 54 was observed in both sexes, and the presence of heteromorphic sex chromosomes of the ZZ/ZW type was detected. The W chromosome has a terminal heterochromatin band that occupies approximately half of the long arm, being this band approximately half the size of the Z chromosome. The FISH assay showed a synteny of the 18S-rDNA and 5S-rDNA genes in the chromosome pair 14, and the absence of interstitial telomeric sites. Our data reinforce the hypothesis of a conservative karyotype structure in Parodontidae and suggest an ancient origin of the sex chromosomes in the fishes of this family.

The use of double fluorescence in situ hybridization to physically map the positions of 5S rDNA genes in relation to the chromosomal location of 18S–5.8S–26S rDNA and a C genome specific DNA sequence in the genus Avena

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Concha Linares ◽  
Juan González ◽  
Esther Ferrer ◽  
Araceli Fominaya
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Diploid Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
26S Rdna ◽  
A Genome ◽  
Rdna Loci ◽  
C Genome

A physical map of the locations of the 5S rDNA genes and their relative positions with respect to 18S–5.8S–26S rDNA genes and a C genome specific repetitive DNA sequence was produced for the chromosomes of diploid, tetraploid, and hexaploid oat species using in situ hybridization. The A genome diploid species showed two pairs of rDNA loci and two pairs of 5S loci located on both arms of one pair of satellited chromosomes. The C genome diploid species showed two major pairs and one minor pair of rDNA loci. One pair of subtelocentric chromosomes carried rDNA and 5S loci physically separated on the long arm. The tetraploid species (AACC genomes) arising from these diploid ancestors showed two pairs of rDNA loci and three pairs of 5S loci. Two pairs of rDNA loci and 2 pairs of 5S loci were arranged as in the A genome diploid species. The third pair of 5S loci was located on one pair of A–C translocated chromosomes using simultaneous in situ hybridization with 5S rDNA genes and a C genome specific repetitive DNA sequence. The hexaploid species (AACCDD genomes) showed three pairs of rDNA loci and six pairs of 5S loci. One pair of 5S loci was located on each of two pairs of C–A/D translocated chromosomes. Comparative studies of the physical arrangement of rDNA and 5S loci in polyploid oats and the putative A and C genome progenitor species suggests that A genome diploid species could be the donor of both A and D genomes of polyploid oats. Key words : oats, 5S rDNA genes, 18S–5.8S–26S rDNA genes, C genome specific repetitive DNA sequence, in situ hybridization, genome evolution.

scholarly journals Evidence of incipient speciation in Astyanax scabripinnis species complex (Teleostei: Characidae)

2014 ◽  
Vol 12 (2) ◽  
pp. 429-438 ◽  
Author(s):  
Jonathan P. Castro ◽  
Maurício O. Moura ◽  
Orlando Moreira-Filho ◽  
Oscar A. Shibatta ◽  
Mateus H. Santos ◽  
...  
Keyword(s):  
Function Analysis ◽  
5S Rdna ◽  
Incipient Speciation ◽  
Lower Altitude ◽  
Geometric Morphometry ◽  
Fin Rays ◽  
Karyotype Structure ◽  
Morphometry Analysis ◽  
Two Populations

Two populations of the Astyanax scabripinniscomplex, isolated by a waterfall with over 100 meters depth and inhabiting different altitudes of the same river (1850 m a.s.l. and 662 m a.s.l.) were compared in reproductive data, geometric morphometry, tooth morphology, anal-fin rays counts, and karyotype, in order to test the hypothesis of speciation between the two populations. The results in the geometric morphometry analysis showed differences between the populations. Discriminant function analysis (DFA) and canonical variance analysis revealed sexual dimorphism. Secondary sexual characters, such as hooks in the anal fin rays of the males are absent in the lower altitude population. Both populations had the same macro karyotype structure, except for the absence of B chromosomes in the lower altitude population. The fluorescence in situ hybridization showed differences for both markers (18S rDNA and 5S rDNA), and reproductive data suggests pre-zygotic reproductive isolation among the two populations. The data showed the absence of gene flow, indicating that an incipient speciation process has occurred, which leads the two populations to follow independent evolutionary pathways.

scholarly journals Snake W Sex Chromosome: The Shadow of Ancestral Amniote Super-Sex Chromosome

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2386
Author(s):  
Worapong Singchat ◽  
Syed Farhan Ahmad ◽  
Nararat Laopichienpong ◽  
Aorarat Suntronpong ◽  
Thitipong Panthum ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Evolutionary Dynamics ◽  
Sex Chromosome ◽  
Chromosomal Rearrangements ◽  
Chromosome Analysis ◽  
Chromosome Conformation ◽  
Principal Mechanism ◽  
Squamate Reptiles ◽  
Genomic Landscape ◽  
Heteromorphic Sex Chromosomes

Heteromorphic sex chromosomes, particularly the ZZ/ZW sex chromosome system of birds and some reptiles, undergo evolutionary dynamics distinct from those of autosomes. The W sex chromosome is a unique karyological member of this heteromorphic pair, which has been extensively studied in snakes to explore the origin, evolution, and genetic diversity of amniote sex chromosomes. The snake W sex chromosome offers a fascinating model system to elucidate ancestral trajectories that have resulted in genetic divergence of amniote sex chromosomes. Although the principal mechanism driving evolution of the amniote sex chromosome remains obscure, an emerging hypothesis, supported by studies of W sex chromosomes of squamate reptiles and snakes, suggests that sex chromosomes share varied genomic blocks across several amniote lineages. This implies the possible split of an ancestral super-sex chromosome via chromosomal rearrangements. We review the major findings pertaining to sex chromosomal profiles in amniotes and discuss the evolution of an ancestral super-sex chromosome by collating recent evidence sourced mainly from the snake W sex chromosome analysis. We highlight the role of repeat-mediated sex chromosome conformation and present a genomic landscape of snake Z and W chromosomes, which reveals the relative abundance of major repeats, and identifies the expansion of certain transposable elements. The latest revolution in chromosomics, i.e., complete telomere-to-telomere assembly, offers mechanistic insights into the evolutionary origin of sex chromosomes.

Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution in Cucumis

Genome ◽  
2016 ◽  
Vol 59 (7) ◽  
pp. 449-457 ◽  
Author(s):  
Zhen-Tao Zhang ◽  
Shu-Qiong Yang ◽  
Zi-Ang Li ◽  
Yun-Xia Zhang ◽  
Yun-Zhu Wang ◽  
...  
Keyword(s):  
Chromosomal Localization ◽  
5S Rdna ◽  
Chromosome Analysis ◽  
45S Rdna ◽  
Evolutionary Patterns ◽  
Site Number ◽  
Rdna Sites ◽  
Wild Accessions ◽  
Ribosomal Dnas

Ribosomal DNAs are useful cytogenetic markers for chromosome analysis. Studies investigating site numbers and distributions of rDNAs have provided important information for elucidating genome organization and chromosomal relationships of many species by fluorescence in situ hybridization. But relevant studies are scarce for species of the genus Cucumis, especially in wild species. In the present study, FISH was conducted to investigate the organization of 45S and 5S rDNA among 20 Cucumis accessions, including cultivars and wild accessions. Our results showed that the number of 45S rDNA sites varied from one to five pairs in different accessions, and most of these sites are located at the terminal regions of chromosomes. Interestingly, up to five pairs of 45S rDNA sites were observed in C. sativus var. sativus, the species which has the lowest chromosome number, i.e., 2n = 14. Only one pair of 5S rDNA sites was detected in all accessions, except for C. heptadactylus, C. sp, and C. spp that had two pairs of 5S rDNA sites. The distributions of 5S rDNA sites showed more variation than 45S rDNA sites. The phylogenetic analysis in this study showed that 45S and 5S rDNA have contrasting evolutionary patterns. We find that 5S rDNA has a polyploidization-related tendency towards the terminal location from an interstitial location but maintains a conserved site number, whereas the 45S rDNA showed a trend of increasing site number but a relatively conserved location.

scholarly journals First chromosome analysis of Thai pufferfish Pao cochinchinensis (Steindachner, 1866)

2020 ◽  
Vol 21 (9) ◽  
Author(s):  
MANACHAYA PISSAPARN ◽  
SUMALEE PHIMPHAN ◽  
PATCHARAPORN CHAIYASAN ◽  
ALONGKLOD TANOAMTONG ◽  
THOMAS LIEHR ◽  
...  
Keyword(s):  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Molecular Cytogenetics ◽  
Nucleolar Organizer ◽  
Chromosome Analysis ◽  
Chromosomal Evolution ◽  
Giemsa Staining ◽  
Heteromorphic Sex Chromosomes ◽  
Almost All

Abstract. Pissaparn M, Phimphan S, Chaiyasan P, Tanoamtong A, Liehr T, Suwannapoom C, Reungsing M, Supiwong W. 2020. First chromosome analysis of Thai pufferfish Pao cochinchinensis (Steindachner, 1866). Biodiversitas 21: 4309-4316. Here first analysis of chromosomes and nucleolar organizer region (NOR) pattern in pufferfish Pao cochinchinensis (Steindachner, 1866) was undertaken. Chromosomal preparations were obtained from kidney of P. cochinchinensis from Chi River basin in Thailand. Chromosomal characteristics were analyzed by Giemsa staining, Ag-NOR banding as well as fluorescence in situ hybridization (FISH) using microsatellites d(CA)15 and d(CGG)10 probes. P. cochinchinensis had 2n = 40 with the fundamental number (NF) 74, both in male and female. The karyotype exhibited 12 metacentric (m), 10 submetacentric (sm), 12 acrocentric (a) and 6 telocentric (t) chromosomes. No differentiated heteromorphic sex chromosomes were observed. NORs were located on short arms adjacent to telomere of the metacentric chromosome pair 4, which coincide with signals of d(CGG)10 probe. FISH with d(CGG)10 sequences were also displayed at the telomeres of most other chromosomes, whereas d(CA)15 repeats highly accumulated throughout almost all entire chromosomes except for centromeric regions. The results of conventional Giemsa staining presented the differentiation even the same genus. The localization of NORs on one pair of chromosomes only is a common characteristic found in many fish groups as well as other vertebrates. Mapping of two distinct microsatellites demonstrated the remarkable chromosomal diversification that characterizes evolution in the genus Pao. Both, conventional and molecular cytogenetics are excellent tools to study, and better understand chromosomal evolution, as well as to uncover biodiversity among fishes.

Comparative mapping of a new repetitive DNA sequence and chromosome region-specific probes unveiling rearrangements in an Amazonian frog complex

Genome ◽  
2021 ◽  
pp. 1-12
Author(s):  
Kaleb Pretto Gatto ◽  
Lucas H.B. Souza ◽  
Juliana Nascimento ◽  
Pablo Suárez ◽  
Luciana Bolsoni Lourenço
Keyword(s):  
Repetitive Dna ◽  
Sex Chromosomes ◽  
Chromosome Region ◽  
Taxonomic Status ◽  
Sister Group ◽  
Z Chromosome ◽  
Genetic Lineage ◽  
New Family ◽  
Heteromorphic Sex Chromosomes

The frog species Physalaemus ephippifer exists in the Amazonian region and harbors heteromorphic Z and W chromosomes. A genetic lineage closely related to this species was recognized based on its mitochondrial DNA and RADseq-style markers, but its taxonomic status is still unclear and has been referred to as Lineage 1 of “P. cuvieri”. The heteromorphic sex chromosomes found in P. ephippifer are not present in this lineage and which of its chromosome pairs is homologous to the sex chromosomes of P. ephippifer remain to be elucidated as well as the role of such a karyotypic divergence in the evolution of these frogs. Here, we described a new family of repetitive DNA and used its chromosomal sites along with the markers detected by a probe constructed from the microdissected segment of the Z chromosome of P. ephippifer to infer chromosomal homology. We also analyzed an unnamed species that is considered to be the sister group of the clade composed of Lineage 1 of “P. cuvieri” and P. ephippifer. Our results suggest that complex rearrangements involving the chromosomes that were inferred to be homeologous to the sex chromosomes of P. ephippifer have occurred during the divergence of this group of frogs.

scholarly journals Cytogenetic Analysis, Heterochromatin Characterization and Location of the rDNA Genes of Hycleus scutellatus (Coleoptera, Meloidae); A Species with an Unexpected High Number of rDNA Clusters

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 385
Author(s):  
Laura Ruiz-Torres ◽  
Pablo Mora ◽  
Areli Ruiz-Mena ◽  
Jesús Vela ◽  
Francisco J. Mancebo ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Satellite Dna ◽  
Karyotype Analysis ◽  
Toxic Substance ◽  
Molecular Data ◽  
Dna Repeats ◽  
Dapi Staining ◽  
Rdna Genes ◽  
Rdna Sites

Meloidae are commonly known as blister beetles, so called for the secretion of cantharidin, a toxic substance that causes irritation and blistering. There has been a recent increase in the interest of the cantharidin anticancer potential of this insect group. Cytogenetic and molecular data in this group are scarce. In this study, we performed a karyotype analysis of Hycleus scutellatus, an endemic species of the Iberian Peninsula. We determined its chromosome number, 2n = 20, as well as the presence of the X and Y sex chromosomes. In addition to a karyotype analysis, we carried out DAPI staining. By fluorescence in situ hybridization we mapped the rDNA clusters on 12 different chromosomes. Compared to others, this species shows an unusually high number of chromosomes carrying rDNA. This is one of the highest numbers of rDNA sites found in the Polyphaga suborder (Coleoptera). Additionally, we isolated a satellite DNA family (Hyscu-H), which was located within the pericentromeric regions of all chromosomes, including the sex chromosomes. The results suggest that Hyscu-H is likely to be one of the most abundant satellite DNA repeats in H. scutellatus.

scholarly journals Large-scale comparative analysis of cytogenetic markers across Lepidoptera

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irena Provazníková ◽  
Martina Hejníčková ◽  
Sander Visser ◽  
Martina Dalíková ◽  
Leonela Z. Carabajal Paladino ◽  
...  
Keyword(s):  
Copy Number ◽  
Large Scale ◽  
Southern Hybridization ◽  
Karyotype Evolution ◽  
Histone H3 ◽  
5S Rdna ◽  
Rdna Genes ◽  
U2 Snrna ◽  
Chromosomal Changes

AbstractFluorescence in situ hybridization (FISH) allows identification of particular chromosomes and their rearrangements. Using FISH with signal enhancement via antibody amplification and enzymatically catalysed reporter deposition, we evaluated applicability of universal cytogenetic markers, namely 18S and 5S rDNA genes, U1 and U2 snRNA genes, and histone H3 genes, in the study of the karyotype evolution in moths and butterflies. Major rDNA underwent rather erratic evolution, which does not always reflect chromosomal changes. In contrast, the hybridization pattern of histone H3 genes was well conserved, reflecting the stable organisation of lepidopteran genomes. Unlike 5S rDNA and U1 and U2 snRNA genes which we failed to detect, except for 5S rDNA in a few representatives of early diverging lepidopteran lineages. To explain the negative FISH results, we used quantitative PCR and Southern hybridization to estimate the copy number and organization of the studied genes in selected species. The results suggested that their detection was hampered by long spacers between the genes and/or their scattered distribution. Our results question homology of 5S rDNA and U1 and U2 snRNA loci in comparative studies. We recommend the use of histone H3 in studies of karyotype evolution.

scholarly journals Identification of sex chromosomes in Eremias velox (Lacertidae, Reptilia) using lampbrush chromosome analysis

2019 ◽  
Vol 13 (2) ◽  
pp. 17-28
Author(s):  
Artem P. Lisachov ◽  
Svetlana A. Galkina ◽  
Alsu F. Saifitdinova ◽  
Svetlana A. Romanenko ◽  
Daria A. Andreyushkova ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Chromosome Analysis ◽  
Lampbrush Chromosome ◽  
Z Chromosome ◽  
Specific Probe ◽  
W Chromosome ◽  
Lacertid Lizards ◽  
Genomic Studies ◽  
Active Transcription

Reptiles are good objects for studying the evolution of sex determination, since they have different sex determination systems in different lineages. Lacertid lizards have been long-known for possessing ZZ/ZW type sex chromosomes. However, due to morphological uniformity of lacertid chromosomes, the Z chromosome has been only putatively cytologically identified. We used lampbrush chromosome (LBC) analysis and FISH with a W-specific probe in Eremiasvelox (Pallas, 1771) to unequivocally identify the ZW bivalent and investigate its meiotic behavior. The heterochromatic W chromosome is decondensed at the lampbrush stage, indicating active transcription, contrast with the highly condensed condition of the lampbrush W chromosomes in birds. We identified the Z chromosome by its chiasmatic association with the W chromosome as chromosome XIII of the 19 chromosomes in the LBC karyotype. Our findings agree with previous genetic and genomic studies, which suggested that the lacertid Z chromosome should be one of the smaller macrochromosomes.

Chromosomal Evolution in the Amolops mantzorum Species Group (Ranidae; Anura) Narrated by Repetitive DNAs

2019 ◽  
Vol 157 (3) ◽  
pp. 172-178 ◽  
Author(s):  
Ya Liu ◽  
Menghuan Song ◽  
Wei Luo ◽  
Yun Xia ◽  
Xiaomao Zeng
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
5S Rdna ◽  
Chromosomal Evolution ◽  
Species Group ◽  
Repetitive Dnas ◽  
Microsatellite Repeats ◽  
Heteromorphic Sex Chromosomes ◽  
Rapid Changes ◽  
5S Rdna Sequence

In an attempt to analyze the organization of repetitive DNAs in the amphibian genome, 7 microsatellite motifs and a 5S rDNA sequence were synthesized and mapped in the karyotypes of 5 Amolops species. The results revealed nonrandom distribution of the microsatellite repeats, usually in the heterochromatic regions, as found in other organisms. These microsatellite repeats showed rapid changes among Amolops species, documenting the recent evolutionary history within this lineage. In contrast, 5S rDNA was localized in chromosomes 5 of all species, suggesting that these chromosomes are homologous within the monophyletic clade. Furthermore, the heteromorphic X and Y sex chromosomes (chromosomes 5) of A.mantzorum, had identical patterns of 5S rDNA, indicating that the subtelocentric Y resulted from a pericentric inversion. Several microsatellite repeats were found in the heteromorphic sex chromosomes, verifying the association of repetitive DNAs with sex chromosome differentiation in A. mantzorum.

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