2026/01/05 by Danon Clemes Cardoso, Maykon Passos Cristiano · 1 voice
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #Insect and Arachnid Ecology and Behavior #Chromosomal and Genetic Variations #Genomics and Phylogenetic Studies
paper · pdf · doi:10.3897/compcytogen.20.162616
openalex publication_date 2026/01/05 · openalex created_date 2026/01/05 · openalex updated_date 2026/07/02
Ribosomal DNA (rDNA) clusters are important cytogenetic markers that can inform both taxonomic delimitation and chromosomal evolution in ants. In this study, we molecularly characterize and validate the widely used 18S rDNA probe applied in cytogenetic studies of Hymenoptera and provide new FISH-based chromosomal data for two previously unstudied leaf-cutting ant species ( Acromyrmex ambiguus (Emery, 1888) and Ac. crassispinus (Forel, 1909)). While the general distribution of 45S rDNA loci in leafcutting is relatively well documented (copy number and site), we expand the comparative framework by testing the phylogenetic structure of rDNA positioning across genera. Our results confirm the conserved number of rDNA loci per species but reveal lineage-specific variation in chromosomal location, including both subterminal and pericentromeric arrangements. Phylogenetic signal analyses suggest non-random patterns consistent with evolutionary constraints in locus positioning. Together, our findings refine current cytogenetic models for leafcutting ants and demonstrate the utility of rDNA as a cytotaxonomic character and evolutionary marker for assessing chromosomal diversification.