On the Origin of Neo-Sex Chromosomes in the Neotropical Dragonflies Rhionaeschna bonariensis and R. planaltica (Aeshnidae, Odonata)

Odonata have holokinetic chromosomes. About 95% of species have an XX/X0 sex chromosome system, with heterogametic males. There are species with neo-XX/neo-XY sex chromosomes resulting from an X chromosome/autosome fusion. The genus includes 42 species found in the Americas. We analyzed the distribu...

Full description

Saved in:
Bibliographic Details
Published in:Insects (Basel, Switzerland) Switzerland), 2022-12, Vol.13 (12), p.1159
Main Authors: Mola, Liliana M, Vrbová, Iva, Tosto, Daniela S, Zrzavá, Magda, Marec, František
Format: Article
Language:English
Subjects:
Aquatic insects
Biological evolution
Chiasma
Chromosome rearrangements
Chromosomes
Cytogenetics
Deoxyribonucleic acid
DNA
DNA probes
dragonflies
Evolution
Females
Fluorescence
Fluorescence in situ hybridization
Genomic in situ hybridization
Heterochromatin
holokinetic chromosomes
Homology
Hybridization
Insects
Labeling
Localization
Males
Meiosis
nucleolar organizer region
Nucleoli
Odonata
Phenols
Rhionaeschna
Rhionaeschna bonariensis
Ribosomal DNA
Sex
Sex chromosomes
Species
Sperm
structural rearrangements
Transposition
X chromosomes
Y chromosomes
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Odonata have holokinetic chromosomes. About 95% of species have an XX/X0 sex chromosome system, with heterogametic males. There are species with neo-XX/neo-XY sex chromosomes resulting from an X chromosome/autosome fusion. The genus includes 42 species found in the Americas. We analyzed the distribution of the nucleolar organizer region (NOR) using FISH with rDNA probes in (n = 12 + neo-XY), (n = 7 + neo-XY), and (n = 13 + X0). In and , the NOR is located on a large pair of autosomes, which have a secondary constriction in the latter species. In , the NOR is located on the ancestral part of the neo-X chromosome. Meiotic analysis and FISH results in led to the conclusion that the neo-XY system arose by insertion of the ancestral X chromosome into an autosome. Genomic in situ hybridization, performed for the first time in Odonata, highlighted the entire neo-Y chromosome in meiosis of , suggesting that it consists mainly of repetitive DNA. This feature and the terminal chiasma localization suggest an ancient origin of the neo-XY system. Our study provides new information on the origin and evolution of neo-sex chromosomes in Odonata, including new types of chromosomal rearrangements, NOR transposition, and heterochromatin accumulation.
ISSN:2075-4450
2075-4450
DOI:10.3390/insects13121159