Chromosome Evolution in the Genus Partamona (Apidae: Meliponini), with Comments on B Chromosome Origin

The genus Partamona includes 33 species of stingless bees, of which 11 were studied cytogenetically. The main goal of this study was to propose a hypothesis about chromosomal evolution in Partamona by combining molecular and cytogenetic data. Cytogenetic analyses were performed on 3 Partamona species. In addition, the molecular phylogeny included mitochondrial sequences of 11 species. Although the diploid number was constant within the genus, 2n = 34, B chromosomes were reported in 7 species. Cytogenetic data showed karyotypic variations related to chromosome morphology and the amount and distribution of heterochromatin and repetitive DNA. The molecular phylogenetic reconstruction corroborated the monophyly of the genus and separated the 2 clades (A and B). This separation was also observed in the cytogenetic data, in which species within each clade shared most of the cytogenetic characteristics. Furthermore, our data suggested that the B chromosome in the genus Partamona likely originated from a common ancestor of the species that have it in clade B and, through interspecific hybridization, it appeared only in Partamona rustica from clade A. Based on the above, Partamona is an interesting genus for further investigations using molecular mapping of B chromosomes as well as for broadening phylogenetic data.

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Cytogenetics of Four Species of the Green Clade Aplastodiscus Lutz, 1950 (Anura: Cophomantinae): New Insights into the Chromosomal Evolution of the Genus

Cytogenetic and Genome Research ◽

10.1159/000512816 ◽

2021 ◽

pp. 1-7

Author(s):

Késsia L. Souza ◽

Marco A. Peixoto ◽

Cynthia A.V. Barreto ◽

Renato N. Feio ◽

Jorge A. Dergam

Keyword(s):

18S Rdna ◽

Chromosome Pair ◽

Chromosomal Evolution ◽

Chromosome Morphology ◽

Small Chromosome ◽

Tree Frog ◽

Chromosome Fusion ◽

Clade B ◽

Number Variation ◽

Molecular Cytogenetic Techniques

The tree frog Aplastodiscus is a Neotropical taxon that encompasses 15 species in the Atlantic forest biome, with one isolated species in the Central Brazilian Cerrado. To date, only 8 species have been karyotyped, showing high levels of diploid number variation, which allowed clustering species in chromosome number groups: 2n = 24 (Aplastodiscus perviridis group), 2n = 22 (Aplastodiscus albofrenatus group), 2n = 20, and 2n = 18 (both within Aplastodiscus albosignatus group). This study aims to report karyotypic information on 4 species from the last 2 groups using classical and molecular cytogenetic techniques and hypothesize chromosomal evolutionary trends within the species groups. Aplastodiscus weygoldti showed 2n = 22; Ag-NOR and FISH 18S rDNA signals were located in the interstitial region of the short arms of chromosome pair 6. Aplastodiscus cavicola, Aplastodiscus sp. 4, and Aplastodiscus sp. 6 showed 2n = 18; Ag-NOR and FISH 18S rDNA bands were located in the terminal region of the long arm of chromosome pair 9. Our results support multiple and independent chromosome fusion events within Aplastodiscus, including a new chromosome fission event. Ag-NOR and FISH 18S rDNA patterns were restricted to the small chromosome pairs, similar to the other species within this genus, and confirm overall chromosome morphology conservation among the genera of Cophomantinae.

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Karyotype and putative chromosomal inversion suggested by integration of cytogenetic and molecular data of the fungus-farming ant Mycetomoellerius iheringi Emery, 1888

Comparative Cytogenetics ◽

10.3897/compcytogen.v14i2.49846 ◽

2020 ◽

Vol 14 (2) ◽

pp. 197-210 ◽

Cited By ~ 1

Author(s):

Ricardo Micolino ◽

Maykon Passos Cristiano ◽

Danon Clemes Cardoso

Keyword(s):

Phylogenetic Relationships ◽

Pericentric Inversion ◽

Phylogenetic Reconstruction ◽

Chromosomal Evolution ◽

Molecular Data ◽

Chromosomal Inversion ◽

Evolutionary Relationships ◽

Congeneric Species ◽

Cytogenetic Analyses ◽

Species Evolution

Comparative cytogenetic analyses are being increasingly used to collect information on species evolution, for example, diversification of closely related lineages and identification of morphologically indistinguishable species or lineages. Here, we have described the karyotype of the fungus-farming ant Mycetomoellerius iheringi Emery, 1888 and investigated its evolutionary relationships on the basis of molecular and cytogenetic data. The M. iheringi karyotype consists of 2n = 20 chromosomes (2K = 18M + 2SM). We also demonstrated that this species has the classical insect TTAGG telomere organization. Phylogenetic reconstruction showed that M. iheringi is phylogenetically closer to M. cirratus Mayhé-Nunes & Brandão, 2005 and M. kempfi Fowler, 1982. We compared M. iheringi with other congeneric species such as M. holmgreni Wheeler, 1925 and inferred that M. iheringi probably underwent a major pericentric inversion in one of its largest chromosomes, making it submetacentric. We discussed our results in the light of the phylogenetic relationships and chromosomal evolution.

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Repetitive DNA landscape in essential A and supernumerary B chromosomes of Festuca pratensis Huds

Scientific Reports ◽

10.1038/s41598-019-56383-1 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Rahman Ebrahimzadegan ◽

Andreas Houben ◽

Ghader Mirzaghaderi

Keyword(s):

Repetitive Sequences ◽

Nuclear Genome ◽

B Chromosome ◽

B Chromosomes ◽

Festuca Pratensis ◽

Ltr Retrotransposons ◽

Chromosome Identification ◽

Satellite Repeats ◽

Low Pass ◽

Illumina Sequence

AbstractHere, we characterized the basic properties of repetitive sequences in essential A and supernumerary B chromosomes of Festuca pratensis Huds. This was performed by comparative analysis of low-pass Illumina sequence reads of B chromosome lacking (−B) and B chromosome containing (+B) individuals of F. pratensis. 61% of the nuclear genome is composed of repetitive sequences. 43.1% of the genome are transposons of which DNA transposons and retrotransposons made up 2.3% and 40.8%, respectively. LTR retrotransposons are the most abundant mobile elements and contribute to 40.7% of the genome and divided into Ty3-gypsy and Ty1-copia super families with 32.97% and 7.78% of the genome, respectively. Eighteen different satellite repeats were identified making up 3.9% of the genome. Five satellite repeats were used as cytological markers for chromosome identification and genome analysis in the genus Festuca. Four satellite repeats were identified on B chromosomes among which Fp-Sat48 and Fp-Sat253 were specific to the B chromosome of F. pratensis.

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Spatial organization of fibroblast and spermatocyte nuclei with different B-chromosome content in Korean field mouse, Apodemus peninsulae (Rodentia, Muridae)

Genome ◽

10.1139/gen-2017-0029 ◽

2017 ◽

Vol 60 (10) ◽

pp. 815-824 ◽

Cited By ~ 4

Author(s):

Tatyana V. Karamysheva ◽

Anna A. Torgasheva ◽

Yaroslav R. Yefremov ◽

Anton G. Bogomolov ◽

Thomas Liehr ◽

...

Keyword(s):

Laser Scanning ◽

Spatial Organization ◽

Constitutive Heterochromatin ◽

B Chromosome ◽

B Chromosomes ◽

Laser Scanning Microscopy ◽

Field Mouse ◽

Apodemus Peninsulae ◽

Basic Set ◽

Korean Field Mouse

Korean field mouse (Apodemus peninsulae) shows a wide variation in the number of B chromosomes composed of constitutive heterochromatin. For this reason, it provides a good model to study the influence of the number of centromeres and amount of heterochromatin on spatial organization of interphase nuclei. We analyzed the three-dimensional organization of fibroblast and spermatocyte nuclei of the field mice carrying a different number of B chromosomes using laser scanning microscopy and 3D fluorescence in situ hybridization. We detected a co-localization of the B chromosomes with constitutive heterochromatin of the chromosomes of the basic set. We showed a non-random distribution of B chromosomes in the spermatocyte nuclei. Unpaired B chromosomes showed a tendency to occur in the compartment formed by the unpaired part of the XY bivalent.

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Biological, ecological, morphological and cytogenetic analyses, with taxonomic notes of Zelurus ochripennis (Stål, 1854) (Hemiptera: Heteroptera: Reduviidae: Reduviinae)

Zootaxa ◽

10.11646/zootaxa.4958.1.21 ◽

2021 ◽

Vol 4958 (1) ◽

pp. 345-358

Author(s):

JADER OLIVEIRA ◽

KAIO CESAR CHABOLI ALEVI ◽

HÉLCIO R. GIL-SANTANA ◽

CLEBER GALVÃO

Keyword(s):

General Morphology ◽

Cytogenetic Data ◽

Cytogenetic Analyses ◽

First Time ◽

Taxonomic Summary

Based on specimens of Zelurus ochripennis (Stål, 1854) collected in the entrance zone of a small terrestrial cave, some biological, ecological, morphological and cytogenetic data, as well, as the general morphology of their nymphs are presented for the first time. A short taxonomic summary of the species is also provided.

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B Chromosomes in Populations of Mammals Revisited

Genes ◽

10.3390/genes9100487 ◽

2018 ◽

Vol 9 (10) ◽

pp. 487 ◽

Cited By ~ 11

Author(s):

Mladen Vujošević ◽

Marija Rajičić ◽

Jelena Blagojević

Keyword(s):

Mammalian Species ◽

B Chromosome ◽

Molecular Techniques ◽

B Chromosomes ◽

General View ◽

Protein Coding ◽

Host Parasite Interactions ◽

Quantitative Characteristics ◽

Host Parasite

The study of B chromosomes (Bs) started more than a century ago, while their presence in mammals dates since 1965. As the past two decades have seen huge progress in application of molecular techniques, we decided to throw a glance on new data on Bs in mammals and to review them. We listed 85 mammals with Bs that make 1.94% of karyotypically studied species. Contrary to general view, a typical B chromosome in mammals appears both as sub- or metacentric that is the same size as small chromosomes of standard complement. Both karyotypically stable and unstable species possess Bs. The presence of Bs in certain species influences the cell division, the degree of recombination, the development, a number of quantitative characteristics, the host-parasite interactions and their behaviour. There is at least some data on molecular structure of Bs recorded in nearly a quarter of species. Nevertheless, a more detailed molecular composition of Bs presently known for six mammalian species, confirms the presence of protein coding genes, and the transcriptional activity for some of them. Therefore, the idea that Bs are inert is outdated, but the role of Bs is yet to be determined. The maintenance of Bs is obviously not the same for all species, so the current models must be adapted while bearing in mind that Bs are not inactive as it was once thought.

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Transmission rate variation among three B chromosome variants in the fish Prochilodus lineatus (Characiformes, Prochilodontidae)

Anais da Academia Brasileira de Ciências ◽

10.1590/0001-3765201387611 ◽

2013 ◽

Vol 85 (4) ◽

pp. 1371-1377 ◽

Cited By ~ 3

Author(s):

MANOLO PENITENTE ◽

TATIANA A. VOLTOLIN ◽

JOSE A. SENHORINI ◽

JEHUD BORTOLOZZI ◽

FAUSTO FORESTI ◽

...

Keyword(s):

Transmission Rate ◽

B Chromosome ◽

B Chromosomes ◽

Rate Variation ◽

Parental Line ◽

Prochilodus Lineatus ◽

Extinction Process ◽

Cytogenetic Studies ◽

Acrocentric Chromosomes ◽

Interesting System

Cytogenetic studies were developed in Prochilodus lineatus (Valenciennes 1836), describing an interesting system of small supernumerary chromosomes. The purpose of this work is to study the frequency and morphology of B chromosomes in individuals from the parental line and the inheritance patterns of these elements in individuals obtained from controlled crosses in the species P. lineatus. The transmission rate of B chromosomes revealed a kB=0.388 for the acrocentric type, a kB=0.507 for the metacentric type and a kB=0.526 for the submetacentric type. The obtained results raise hypothesis that B-acrocentric chromosomes are involved in an extinction process in this species, while the metacentric and submetacentric supernumerary elements comprises a neutral mechanism and follows a Mendelian transmission rate.

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Identification of a family of repeated sequences on the rye B chromosome

Genome ◽

10.1139/g90-137 ◽

1990 ◽

Vol 33 (6) ◽

pp. 908-913 ◽

Cited By ~ 62

Author(s):

Michael J. Sandery ◽

John W. Forster ◽

Richard Blunden ◽

R. Neil Jones

Keyword(s):

Secale Cereale ◽

Direct Evidence ◽

B Chromosome ◽

Repeat Sequence ◽

B Chromosomes ◽

Repeated Sequences ◽

Significant Heterogeneity ◽

Origin And Evolution ◽

The Family

A novel family of highly repeated sequences on the B chromosome of rye (Secale cereale) has been identified. The D1100 family has not been detected on the rye A chromosomes and shows little or no homology to any previously described repeat sequence in rye. In addition, different rye species, and different B chromosomes within the same species, show significant heterogeneity in the arrangement of the D1100 sequences. An EcoRI clone of a member of the family has been obtained. These results provide direct evidence for the organisation and nature of the B-chromosome DNA in rye, and they are discussed in relation to the origin and evolution of rye B chromosomes.Key words: B chromosome, Secale cereale, repeated sequences.

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MOSAICISM OF AN ABNORMALLY LONG B CHROMOSOME IN A BOY WITH PHYSICAL AND MENTAL RETARDATION

PEDIATRICS ◽

10.1542/peds.39.1.68 ◽

1967 ◽

Vol 39 (1) ◽

pp. 68-74

Author(s):

Lillian Y. F. Hsu ◽

Iris Nemhauser ◽

Hilda K. Bettmann ◽

Edna H. Sobel

Keyword(s):

Mental Retardation ◽

Short Stature ◽

Cell Line ◽

Normal Cell ◽

B Chromosome ◽

B Chromosomes ◽

Normal Cell Line

An 11-year-old boy with short stature, mental retardation, low-set ears, simian creases, unusual dermatoglyphic patterns, and bilateral dysplastic mid-phalanges of the fifth fingers was found to have mosaicism in both leukocyte and fibroblast (skin) cultures. The normal cell-line predominated and the second cell-line contained an abnormally long chromosome B. The autoradiographic studies suggest that the abnormally long chromosome may involve a No. 5 which contains a translocated on inserted segment of an unknown donor autosome. The possible mechanism for the occurrence of this abnormality is discussed. Nine other instances of abnormally long B chromosomes (with lengthened long arm due to translocation) are reviewed and compared.

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Can the Cambrian explosion be inferred through molecular phylogeny?

Development ◽

10.1242/dev.1994.supplement.15 ◽

1994 ◽

Vol 1994 (Supplement) ◽

pp. 15-25

Author(s):

Hervé Philippe ◽

Anne Chenuil ◽

André Adoutte

Keyword(s):

Phylogenetic Trees ◽

18S Rrna ◽

Phylogenetic Reconstruction ◽

Cambrian Explosion ◽

Bootstrap Support ◽

Time Interval ◽

Short Time Interval ◽

Data Set ◽

Molecular Phylogenetic ◽

Animal Phyla

Most of the major invertebrate phyla appear in the fossil record during a relatively short time interval, not exceeding 20 million years (Myr), 540-520 Myr ago. This rapid diversification is known as the `Cambrian explosion'. In the present paper, we ask whether molecular phylogenetic reconstruction provides confirmation for such an evolutionary burst. The expectation is that the molecular phylogenetic trees should take the form of a large unresolved multifurcation of the various animal lineages. Complete 18S rRNA sequences of 69 extant representatives of 15 animal phyla were obtained from data banks. After eliminating a major source of artefact leading to lack of resolution in phylogenetic trees (mutational saturation of sequences), we indeed observe that the major lines of triploblast coelomates (arthropods, molluscs, echinoderms, chordates...) are very poorly resolved i.e. the nodes defining the various clades are not supported by high bootstrap values. Using a previously developed procedure consisting of calculating bootstrap proportions of each node of the tree as a function of increasing amount of nucleotides (Lecointre, G., Philippe, H. Le, H. L. V. and Le Guyader, H. (1994) Mol. Phyl. Evol., in press) we obtain a more informative indication of the robustness of each node. In addition, this procedure allows us to estimate the number of additional nucleotides that would be required to resolve confidently the currently uncertain nodes; this number turns out to be extremely high and experimentally unfeasible. We then take this approach one step further: using parameters derived from the above analysis, assuming a molecular clock and using palaeontological dates for calibration, we establish a relationship between the number of sites contained in a given data set and the time interval that this data set can confidently resolve (with 95% bootstrap support). Under these assumptions, the presently available 18S rRNA database cannot confidently resolve cladogenetic events separated by less than about 40 Myr. Thus, at the present time, the potential resolution by the palaeontological approach is higher than that by the molecular one.

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