New data on karyotype, spermatogenesis and ovarian trophocyte ploidy in three aquatic bug species of the families Naucoridae, Notonectidae, and Belostomatidae (Nepomorpha, Heteroptera)

By

Stoianova, Desislava
Simov, Nikolay
Quang Vu, Manh
Nguyen, Duc Minh
Grozeva, Snejana

Type

Article

Date of Publication

2020

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

14

Series / Issue

Issue: 1

Pages

139--156

Subjects

achiasmate male meiosis (achiasmy) , B-chromosomes , Diplonychus rusticus , Ilyocoris cimicoides , karyotype , Notonecta glauca , nurse cells , South Europe and Southeast Asia

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/CompCytogen.v14i1.48709

 

Abstract

We report the karyotype, some aspects of spermatogenesis, and ovarian trophocytes ploidy in three aquatic bug species:Ilyocoris cimicoides(Linnaeus, 1758),Notonecta glaucaLinnaeus, 1758, andDiplonychus rusticusFabricius, 1871 from previously unexplored regions – South Europe (Bulgaria) and Southeast Asia (Vietnam). Our results add considerable support for the published karyotype data for these species. InI. cimicoides, we observed achiasmate male meiosis – the first report of achiasmy for the family Naucoridae. More comprehensive cytogenetic studies in other species of the Naucoridae are required to elucidate the role of achiasmy as a character in the systematics of the family.Our observations on the association between phases of spermatogenesis and developmental stages inI. cimicoidesandN. glaucadiffer from the previously published data. In these species, we assume that the spermatogenesis phases are not strongly associated with certain developmental stages. For further cytogenetic studies (on the Balkan Peninsula), we recommend July as the most appropriate month for collection ofI. cimicoidesandN. glauca.In the ovaries of both species, we studied the level of ploidy in metaphase and interphase trophocytes. InI. cimicoides, diploid and tetraploid metaphase trophocytes were found. Heteropycnotic elements, observed in interphase trophocytes of this species, represented the X chromosomes. It allowed us to determine the trophocytes ploidy at interphase (2n was repeated up to 16 times). The situation withN. glaucawas different. The metaphase trophocytes were diploid and we were not able to determine the ploidy of interphase trophocytes since such conspicuous heteropycnotic elements were not found. The scarce data available suggest a tendency for a low level of trophocyte ploidy in the basal infraorders (Nepomorpha and Gerromorpha) and for a high level in the more advanced Pentatomomorpha. Data about this character in species from other infraorders are needed to confirm that tendency.