Genomic dispersion of 28S rDNA during karyotypic evolution in the ant genusMyrmecia (Formicidae)

  title={Genomic dispersion of 28S rDNA during karyotypic evolution in the ant genusMyrmecia (Formicidae)},
  author={Hirohisa Hirai and Masatoshi Yamamoto and Robert W. Taylor and Hirotami T. Imai},
The chromosomal localization of 28S rDNA was investigated in 16 species of the Australian ant genusMyrmecia, with 2n numbers ranging from 4 to 76, using the fluorescence in situ hybridization method and karyographic analysis. A unique phenomenon was observed: the number of chromosomes carrying 28S rDNA increases from 2 in species with low chromosome numbers to 19 in species with high chromosome numbers. This is termed rDNA dispersion. Centric fission and a reciprocal translocation that occurs… 

Localization of rDNA sites in holocentric chromosomes of three species of triatomines (Heteroptera, Triatominae).

The results obtained did not agree with the expected localization of rDNA genes in the sex chromosomes of triatomines, as demonstrated by silver impregnation, and suggest that the chromosome reorganization that occurred in this group during evolution may be a more important mechanism involved in rDNA distribution.

Evolutionary insight on localization of 18S, 28S rDNA genes on homologous chromosomes in Primates genomes

The hypothesis that different mechanisms are responsible for the distribution of the ribosomal DNA cluster in Primates is supported by an extensive variability in the topology of the rDNA signals across studied species.

Evolutionary dynamics of rDNA clusters on chromosomes of moths 1 and butterflies ( Lepidoptera ) 2 3

31 We examined chromosomal distribution of major ribosomal DNAs (rDNAs), clustered in the nucleolar 32 organizer regions (NORs), in 18 species of moths and butterflies using fluorescence in situ 33

Evolutionary dynamics of rDNA clusters on chromosomes of moths and butterflies (Lepidoptera)

E ectopic recombination is proposed, i.e., homologous recombination between repetitive sequences of non-homologous chromosomes, as a primary motive force in rDNA repatterning.

Chromosomal divergence and evolutionary inferences in Pentatomomorpha infraorder (Hemiptera, Heteroptera) based on the chromosomal location of ribosomal genes

The arrangement of 45S DNAr in the chromosomes of 12 new species of Heteroptera is characterized and the main evolutionary events related to the genomic reorganization of these species during the events of chromosome and karyotype evolution in Pentatomomorpha infraorder are discussed.

Comparative molecular cytogenetics in Melipona Illiger species (Hymenoptera, Apidae)

The aim of this study was to perform karyotype analyzes on Melipona species from different regions of Brazil, with a greater sampling representative of the Amazonian fauna and using conventional, fluorochrome staining and FISH with heterologous rDNA probes.

New arrangements on several species subcomplexes of Triatoma genus based on the chromosomal position of ribosomal genes (Hemiptera - Triatominae).

  • S. PitaP. Lorite F. Panzera
  • Biology
    Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases
  • 2016

Genomic Differentiation of 18S Ribosomal DNA and β-Satellite DNA in the Hominoid and its Evolutionary Aspects

The chromosome localization of two human multisequence families, rDNA and β-satellite (β-sat) DNA, was determined in humans and apes using double color fluorescence in-situ hybridization and proposed the following chromosomal phylogenetic divergence order in hominoids: gibbon-siamang-orangutan-gorilla-human-chimpanzee-bonobo.

Cytogenetic Studies on Workers of the Neotropical Ant Wasmannia auropunctata (Roger 1863) (Hymenoptera: Formicidae: Myrmicinae)

The pericentromeric region of many chromosomes was stained with DAPI, evidencing the occurrence of AT bases rich heterochromatin and seems to constitute an interesting specific taxonomic character in Wasmannia auropunctata.



FISH analysis of the telomere sequences of bulldog ants (Myrmecia: Formicidae)

Chromosomes from several species of ants from the genus Myrmecia were hybridized with deoxyoligomer probes of either (T2AG2)7, the putative insect telomere repeat sequence, or (T1AG3)3, the vertebrate telomeres repeat sequence to speculate on the origin of the new telomees as the chromosome numbers increased.

Karyotypes, C-banding, and chromosomal location of active nucleolar organizing regions in Tapinoma (Hymenoptera, Formicidae).

The analysis of NOR sites in these species proved the existence of primary activity NOR in one or two chromosomes, respectively, whereas the other chromosomes showed secondary activity NOR, expressed only in a minority of cells.

Multiplication of 28S rDNA and NOR activity in chromosome evolution among ants of the Myrmecia pilosula species complex

It is suggested that the rDNA in the ancestral stock of the M. pilosula complex was localized originally in a pericentromeric C- band, and multiplied by chance with time during saltatory increases in C-banding following episodes of centric fission.

Karyotype evolution in Australian ants

The data provide little support for the ancestral chromosome number in ants having been high with subsequent reduction, but suggest that the ancestral number was either very low with subsequent increase or coincident with the present mode (“modal hypothesis”).

Mutability of constitutive heterochromatin (C-bands) during eukaryotic chromosomal evolution and their cytological meaning.

A quantitative analysis of the alterations of constitutive heterochromatin in eukaryotic chromosomal evolution was attempted using the accumulated C-banding data available for mammals, amphibians,

Chromosomal polymorphisms involving telomere fusion, centromeric inactivation and centromere shift in the ant Myrmecia (pilosula) n=1

It is a noteworthy finding that active nucleolus organizer (NOR) sites, in terms of silver staining, are tightly linked with the centromere in this species, and that both the Centromere and NOR of A2 were inactivated after the telomere fusion.

Phase specific Ag-staining of nucleolar organizer regions (NORs) and kinetochores in the Australian ant Myrmecia croslandi

Detailed localization of NORs on metaphase chromosomes of the Australian ant Myrmecia croslandi were examined using rDNA: DNA in situ hybridization and cytological evidence that nucleoli appeared exactly at the expected NOR sites was supported.

Sequence arrangement of the rDNA of Drosophila melanogaster

The structural organization of ribosomal DNA in drosophila melanogaster

Experimental bases for the minimum interaction theory. I. Chromosome evolution in ants of the Myrmecia pilosula species complex (Hymenoptera: Formicidae: Myrmeciinae)

Chromosome evolution in primitive Australian ants of the Myrmecia pilosula species complex is investigated in the context of the minimum interaction theory. Under the minimum interaction theory,