A new approach to chromosomal evolution in the giant water bug (Heteroptera: Belostomatidae)

Abstract

The genus Belostoma, known colloquially as “giant water bugs,” presents striking cytogenetic diversity and extensive chromosome variability. Notwithstanding, its karyotype evolution is not well understood. We analyzed 8 species of Belostoma (77 samples). The meiotic analysis revealed 2n = 14 + XY for Belostoma horvathi and Belostoma candidulum; 2n = 22 + XY for Belostoma cummings; 2n = 26 + X1X2Y for Belostoma dentatum, Belostoma elongatum, and Belostoma discretum; and 2n = 26 + X1X2X3Y for Belostoma testacopallidum and Belostoma dilatatum. All species showed holokinetic chromosomes. Based on heterochromatin distribution patterns and 18S rDNA, the species of the genus Belostoma were separated into four groups. The analysis of C0t-1 DNA showed that the repetitive DNA, partly composed of microsatellite DNA, was absent on the Y chromosome. Fluorescent in situ hybridization (FISH) using a microdissected X chromosome in species with simple sex system presents uniform hybridization in the nuclear region corresponding to the X chromosome. Species with multiple systems revealed discrete markings. The present data in conjunction with the existing literature led us to propose a new evolutionary hypothesis for the group, with an ancestral karyotype with a low diploid number, simple sex determination system, and nucleolus organizer regions (NORs) on the sex chromosomes. That karyotype would have originated other karyotypes through agmatoploidy, simploidy, heterochromatinization, and movement of the 18S rDNA.

Holocentric chromosome evolution in kissing bugs (Hemiptera: Reduviidae: Triatominae): diversification of repeated sequences

“…Knowledge about the DNA sequences that composed sex chromosomes in heteropteran species is very limited. Recently, Gallo et al [ 34 ] have analysed the repetitive DNA composition of the Y and X chromosomes in several species of the giant water bugs (Heteroptera: Belostomatidae). These authors showed that repetitive DNA was absent on the Y chromosome while X chromosomes and autosomes shared repetitive sequences.…”

Belostomatidae Leach, 1815 (Insecta: Hemiptera: Heteroptera: Nepomorpha) of northeastern Brazil

“…24) (Ribeiro 2007); phallosoma with ventroapical protuberance of diverticulum strongly developed (Ribeiro 2007); dorsal arms of phallosoma broad, not widely separate (Figs 30-31) (Ribeiro et al 2017). (Ribeiro 2007), Amazonas (Nieser 1975;Ribeiro 2007;Almeida et al 2019), Maranhão (this work), Mato Grosso (Ribeiro 2007), Mato Grosso do Sul (Nieser 1975;Ribeiro 2007;Gallo et al 2017;Aranda et al 2018), Minas Gerais (De Carlo 1938;Nieser & Melo 1997;Melo & Nieser 2004;Amato & Amato 2005;Ribeiro 2007), Pará (Nieser 1975;Ribeiro 2005Ribeiro , 2007Almeida et al 2019), Piauí (Ribeiro 2007;this work), Rio de Janeiro (Mayr 1871;Ribeiro 2005), Rio Grande do Sul (Mayr 1863;Lauck 1964;Nieser 1975;Lanzer 1976;Ribeiro 2007;Ribeiro et al 2017;Gauterio et al 2021), Rondônia (Nieser 1975;Ribeiro 2007), Roraima (Almeida et al 2019), São Paulo (Ribeiro 2007); PARAGUAY (Montandon 1895); PERU (Lauck 1964); URUGUAY (Ruffinelli & Pirán 1959).…”

Comparative analysis of chromosome numbers and sex chromosome systems in Paraneoptera (Insecta)

“…Besides, a great number of research papers have been published too (e.g. Panzera et al 2010 , 2012 ; Kuznetsova et al 2012 ; Bardella et al 2012 , 2013 , 2014 ; Chirino et al 2013 , 2017 ; Sadílek et al 2013 , 2019a , 2019b , 2020 ; Chirino and Bressa 2014 ; Pita et al 2014 , 2016 ; Kaur and Gaba 2015 ; Stoianova et al 2015 ; Golub et al 2016 , 2017 , 2018 ; Angus et al 2017 ; Gallo et al 2017 ; Grozeva et al 2019 ; for other references see aforementioned reviews). As a result, the number of karyotyped species increased significantly and knowledge about karyotypes and their evolution in true bugs was expanded.…”

“…In a series of publications on the family Tingidae ( Golub et al 2015 , 2016 , 2017 , 2018 ) it was shown, firstly, that lace bugs also lost this telomere motif and, secondly, that closely related species of lace bugs share the same or similar karyotypes (at least, the same number of autosomes) but differ in the rDNA site location. Significant advances have been made recently in cytogenetics of the true water bug infraorder Nepomorpha , the families Nepidae , Aphelocheiridae and especially Belostomatidae , which is the best-studied family within this group in terms of karyotypes, meiosis and chromosome evolution (e.g., Kuznetsova et al 2012 ; Chirino et al 2013 , 2017 ; Grozeva et al 2013 ; Wisoram et al 2013 ; Gallo et al 2017 ). Species of the genus Belostoma Latreille 1807 ( Belostomatidae ) were shown to differ from one another in chromosome number and sex chromosome systems; besides, interstitial telomere sequences (ITS) found in some species were interpreted as signs of telomere-telomere fusions that took place in the evolution of the genus ( Chirino et al 2017 ).…”