A Cytogenetic Approach to the Study of Neotropical Odontomachus and Anochetus Ants (Hymenoptera: Formicidae)

Abstract

Odontomachus (Latreille) and Anochetus (Mayr) (Hymenoptera: Formicidae: Ponerinae) are closely related pantropical genera of ponerine ants that share morphological and behavioral characteristics. A comparative study was carried out using conventional Giemsa staining, fluorochrome staining, and fluorescent in situ hybridization. Karyotypes revealed a higher stability in chromosome number among Odontomachus species than among Anochetus species. We observed a higher frequency of metacentric chromosomes in the karyotypes of Anochetus compared with the more common telocentrics of Odontomachus species. Differences in the localization of rDNA genes on chromosomes between the two genera also were verified, rDNA genes were found on telocentric and submetacentric chromosomes in Anochetus and on telocentric chromosomes in Odontomachus. Our cytogenetic results lend support to Brown's hypothesis that Odontomachus has evolved from a lineage of Anochetus. The karyotype divergence of both genera can be explained by a model of evolution in which there is a tendency to the increase of chromosome number by centric fission. Supporting evidence for this hypothesis is discussed.

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

“…Chromosome positives for CMA3 (chromomycin A3) and DAPI (4',6-diamidino-2-phenylindole) were evidenced in several Hymenoptera, such as bees of the genera Melipona Illiger 1806, Partamona Schwarz 1939 and Trigona Jurine 1807 (Rocha et al 2002;Costa et al 2004;Brito et al 2005) and in the ants Tapinoma erraticum (Latreille 1798) [=T. nigerrima (Nylander 1856)] (Lorite et al 1996(Lorite et al , 1997 and few species of the genera Anochetus Mayr 1861 and Odontomachus Latreille 1804 (Santos et al 2010). Acridine orange is also used to provide the standard of chromosomal banding (Verma et al 1977), and there is at least one record of its use in ants with Dinoponera lucida Emery, 1901 (Barros et al 2009).…”

Cytogenetic studies in Trachymyrmex holmgreni Wheeler, 1925 (Formicidae: Myrmicinae) by conventional and molecular methods

“…In ants from the Neotropical region, the reports of 18S or 45S physical location are available for 25 species (Mariano et al, 2008;Aguiar et al, 2011;Santos et al, 2010Santos et al, , 2016Barros et al, 2012Barros et al, , 2015Barros et al, , 2016Teixeira et al, 2017;Aguiar et al, 2017). The majority of these species present the GC-rich regions coinciding with the nucleolus organizer regions (NORs).…”

Occurrence of pre-nucleolar bodies and 45S rDNA location on the chromosomes of the ant Mycocepurus goeldii (Forel) (Formicidae, Myrmicinae, Attini)

“…The CMA 3 fluorochrome has already been applied to chromosomes of the family Formicidae (Lorite et al 1997, Mariano et al 2008, Santos et al 2010), which has marks on one single pair of chromosomes. This GC‐rich chromatin coincided with the location of nucleolus organizing regions (NOR), as occurs in other organisms (Schmidt and Guttenbach 1988; Reed and Phillips 1995).…”