The relevance of chromosome fissions for major ribosomal DNA dispersion in hymenopteran insects

Author(s)

Menezes, Rodolpho S. T. ^{[1, 2]} ; Cabral-de-Mello, Diogo C. ^[3] ; Milani, Diogo ^[3] ; Bardella, Vanessa B. ^[3] ; Almeida, Eduardo A. B. ^[1]

Affiliation

^[1] Univ Sao Paulo, Lab Biol Comparada & Abelhas, Dept Biol, Fac Filosofia Ciencias & Letras FFCLRP, Ribeirao Preto - Brazil

^[2] Univ Fed Santa Maria UFSM, Programa Posgrad Biodiversidade Anim, Ctr Ciencias Nat & Exatas, Santa Maria, RS - Brazil

^[3] Univ Estadual Paulista UNESP, Dept Biol Geral & Aplicada, Inst Biociencias, Rio Claro - Brazil

• Document type: Journal article
• Source: JOURNAL OF EVOLUTIONARY BIOLOGY; v. 34, n. 9 AUG 2021.
• Web of Science Citations: 1

Abstract

Ribosomal DNA (rDNA) loci are essential for cellular metabolism due to their participation in ribosome biogenesis. Although these genes have been widely cytogenetically mapped, the evolutionary mechanisms behind their variability in number and chromosomal location remain elusive, even in well-known biological groups, such as ants, bees and wasps (Insecta: Hymenoptera). To address this question in Hymenoptera and therefore advance the understanding of rDNA evolution in insects in general, we integrated molecular cytogenetic data, a phylogenomic framework, model-based predictions and genome sequencing. Hence, we assessed the main evolutionary trends shaping the chromosomal distribution of rDNA loci in Hymenoptera. We noticed the conservation of one site of rDNA per haploid genome, suggesting that a single 45S rDNA locus is the putative ancestral pattern for aculeate Hymenoptera. Moreover, our results highlighted a nonrandom distribution of rDNA in Hymenoptera karyotypes, as well as a lineage-specific preferential location. The proximal location of rDNA is favoured in species with multiple loci and in the two families of Hymenoptera that show the highest range of chromosome numbers: Formicidae and Vespidae. We propose that chromosome fissions have played a crucial role in the distribution pattern of rDNA loci through the evolutionary diversification of Hymenoptera. Moreover, our genomic analysis of two species, one with a single locus of rDNA and one with multiple loci, supported that loci multiplication is followed by sequence divergence. Our results provide detailed information about the number and chromosomal position of rDNA in Hymenoptera and, therefore, broaden our knowledge regarding rDNA evolutionary dynamics in insects. (AU)

• FAPESP's process: 16/21098-7 - Bridging chromosomal evolution and diversification in neotropical swarm-founding wasps through phylogenomics
• Grantee: Rodolpho Santos Telles de Menezes
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 19/19069-7 - Investigating the evolution of satellite DNAs in holocentric chromosomes of pest species
• Grantee: Diogo Cavalcanti Cabral de Mello
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/02432-0 - Organization and chromosomal evolution of repetitive elements in genomes of social wasps
• Grantee: Rodolpho Santos Telles de Menezes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/09666-5 - Phylogenomic systematics, comparative morphology and biogeography of bees (Hymenoptera: Anthophila)
• Grantee: Eduardo Andrade Botelho de Almeida
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/11763-8 - Contributions to understanding of structure and evolution of sex chromosome systems using as models grashopper and cricket species
• Grantee: Diogo Cavalcanti Cabral de Mello
• Support Opportunities: Regular Research Grants