Karyotype evolution in Australian ants

  title={Karyotype evolution in Australian ants},
  author={Hirotami T. Imai and Ross H. Crozier and Robert W. Taylor},
Abstract105 Australian ant species, including members of the important primitive genera Amblyopone and Myrmecia, were karyotyped using a C-banding air-drying technique. The observed haploid numbers in this survey ranged from 2n=84 (the highest known in the Hymenoptera) to 2n=9. Seven types of chromosome rearrangement were detected, namely: Robertsonian rearrangements, pericentric inversions, saltatory changes in constitutive heterochromatin, simple reciprocal translocations, complex… 

The Role of Fusion in Ant Chromosome Evolution: Insights from Cytogenetic Analysis Using a Molecular Phylogenetic Approach in the Genus Mycetophylax

The results obtained show the importance of fusions in chromosome changes towards a chromosome number reduction in Formicidae and how a phylogenetic background can be used to reconstruct hypotheses about chromosomes evolution.

Karyotype evolution in ants (Hymenoptera: Formicidae), with a review of the known ant chromosome numbers

Karyotype evolution has followed chromosome-mutation processes able to change not only chromosome number but also chromosome morphology, and Robertsonian centric fusions and fissions seem to be the main processes that generate changes in ant karyotypes.

Cytogenetic and Molecular Analyses Reveal a Divergence between Acromyrmex striatus (Roger, 1863) and Other Congeneric Species: Taxonomic Implications

A diploid number of 22 chromosomes is reported for A. striatus, which is restricted to the southern states of Santa Catarina and Rio Grande do Sul and provides interesting insights into the phylogenetic position of A.striatus among the leafcutter ants and the tribe Attini.

First cytogenetic characterization of a species of the arboreal ant genus Azteca Forel, 1978 (Dolichoderinae, Formicidae)

The karyotype analysis ofAzteca trigona allowed the identification of cytogenetic markers that will be helpful in a difficult taxonomic group as Azteca and discussion about evolutionary aspects of the genome organization.

Contribution of Cytogenetics to the Debate on the Paraphyly of Pachycondyla spp. (Hymenoptera, Formicidae, Ponerinae)

The cytogenetic studies reveal the karyotype diversity in the ant genus Pachycondyla and reinforce the hypothesis on the paraphyly of Pachy Condyla.

Cytogenetic characterization of the ant Trachymyrmex fuscus Emery, 1934 (Formicidae: Myrmicinae: Attini) with the description of a chromosomal polymorphism

The presence of heterochromatin on all centromeric and pericentromeric chromosomes of T. fuscus suggests that the size difference observed in the submetacentric pair in the SB and BB workers is not related to the heterochROMatin but to a duplication of euchromatic regions through intra- or inter- chromosomal rearrangements.

Rapid Chromosomal Changes Inferred from Variation in Mitochondrial DNA Among Populations of the LeafBeetle Chrysolina aurichalcea (Coleoptera: Chrysomelidae) in Japan

The data suggest that chromosomal changes occurred rapidly and recently in Japanese populations of the leaf beetle Chrysolina aurichalcea and the association between speciation and chromosomal rearrangements is discussed.

B chromosome variation in Euphydryas colon (Lepidoptera: Nymphalidae)

Results suggest that a mechanism to boost the number of B chromosomes exists in males of E. colon, a classic case of B chromosome variation.

Chromosomal variation among populations of a fungus-farming ant: implications for karyotype evolution and potential restriction to gene flow

T. holmgreni shows considerable variation in karyotype length and might provide a second example of centromere drive in ants, similar to what has previously been observed in Solenopsis fire ants.

The evolution of haploid chromosome numbers in Meliponini

It is concluded that Robertsonian fission and fusions are unlikely to be the cause of chromosomal rearrangements that originated the current karyotypes in Meliponini.



Cytotaxonomic Studies on some Australian Dolichoderine Ants (Hymenoptera: Formicidae)

It is concluded that the principles of karyotype evolution in other bisexual animals apply also to ants despite their haplo-diploidy, and the genetic variability now known in hymenopteran populations is concluded.

Karyotype stability and DNA variability in the Acrididae

The Acrididae are frequently quoted as one of the classic examples of karyotypic stability but the relationship of kARYotypes within the family must be considerably more complex than has formerly been supposed.

Karyotypic fissioning and canid phylogeny.

  • N. B. Todd
  • Biology
    Journal of theoretical biology
  • 1970

Karyotypes of twenty-one ant species (Hymenoptera; formicidae), with reviews of the known ant karyotypes.

  • R. Crozier
  • Biology
    Canadian journal of genetics and cytology. Journal canadien de genetique et de cytologie
  • 1970
Six dolichoderine species have haploid numbers: 9 (Iridomyrmex pilifer, I. sp. nr. pilifer, Dorymyrmex ?thoracicus, D. ?pulchellus), 13 (D. bicolor) and 16 (Forelius foetidus). Robertsonian changes

B-chromosomes in the myrmicine ant, Leptothorax spinosior

B-chromosomes of ants (Formicidae, Hymenoptera) were observed for the first time in the myrmicine ant Leptothorax spinosior using an improved squash technique and the analysis of heterochromatic bodies in female cells suggested that B- chromosomes are maintained in oocytes but almost totally eliminated from nurse cells.

Genetic differentiation between populations of the ant Aphaenogaster ‘rudis’ in the Southeastern United States

Chromosomal and isozyme variation was examined in populations of the ant Aphaenogaster ‘rudis’ and no unequivocal evidence was found for an overall departure of genotype frequencies from those expected under the Hardy-Weinberg Law.

Karyological studies of Japanese ants (Hymenoptera, Formicidae)

The karyotypes of nine Japanese ants in three subfamilies were successfully analysed by the improved squash technique and it was found that the variation of chromosome number observed in P. nodus was caused by Robertsonian type polymorphism.

Causes and consequences of Robertsonian exchange

Evidence is presented for a third type of exchange, one involving breakage within the centromere itself, in the grasshopper Percassa rugifrons, which has led to a modification in both the frequency and the distribution of chiasmata.

Social structuring of mammalian populations and rate of chromosomal evolution.

The results show that chromosomal evolution has been faster in placental mammals than in other vertebrates or molluscs, consistent with published evidence that placentals have also been evolving unusually fast in anatomy and way of life.


Tapinoma melanocephalum has a haploid number of 5, comprising four metacentrics and one acrocentric chromosome. T. sessile karyotypes (n = 8) comprise seven metacentric chromosomes and one that has