Open Access

ARTICLE

Ultrastructural analysis of sperm from the genus Idarnes (Hymenoptera: Chalcidoidea, Sycophaginae)

by KHESLLER PATRÍCIA OLAZIA^1,2, JULIANA SOUZA DA SILVA¹, GUILHERME SIRIMARCO DE SOUZA TONELLI¹, SÔNIA NAIR BÁO^1,*

1 Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
2 Instituto de Ciências da Saúde, Coordenação de Ciências Biológicas, Universidade Paulista UNIP, Brasília, Brazil

* Corresponding Author:SÔNIA NAIR BÁO. Email:

BIOCELL 2022, 46(1), 275-283. https://doi.org/10.32604/biocell.2022.016603

Received 01 April 2021; Accepted 26 May 2021; Issue published 28 September 2021

Abstract

In this study, the sperm ultrastructure of three species of Idarnes genus was investigated using light and transmission electron microscopy. Spermatozoon morphology of the three species was similar to that of most Chalcidoidea, with helicoidally twisted nucleus and flagellum. The head region consists of an acrosome and a nucleus; the nucleus-flagellum transition region characterized by the presence of mitochondrial derivatives and the centriolar adjunct; a flagellum region, which includes the axoneme with microtubular arrangement 9 + 9 + 2 and two mitochondrial derivatives. However, the sperm of these three species exhibit features that discriminate one species from each other: (1) only one species, Idarnes sp. 2 (carme group) exhibited an extracellular sheath surrounding the anterior portion of the nucleus, which extends to the anterior region of the flagellum, but it did not present filaments; (2) the acrosome in the three species was quite different, Idarnes sp. 1 and Idarnes sp. 2 (carme group) has two compartments (acrosomal and subacrosomal vesicles) while Idarnes sp. 3 (flavicollis group) has a third compartment (perforatorium); (3) the centriolar adjunct elongated and its location among the mitochondrial derivatives is similar for the three species analyzed; (4) mitochondrial derivatives differ between the species, with triangular (Idarnes sp. 1 and sp. 3) and elongated or flat shaped (Idarnes sp. 2) appearance. These data shows that sperm structure may differ within the same genus and confirms the potential of these cells in phylogenetic and taxonomic analyses in the Chalcidoidea superfamily, as well as in Hymenoptera in general.

---

Keywords

---