Sperm characteristics of four species of Odonata (Insecta)

A ordem Odonata compreende cerca de 5500 espécies e é atualmente dividida em três subordens: Zygoptera, que compreende 19 famílias; Anisozygoptera, contendo táxons fósseis e apenas um gênero vivente com duas espécies; e Anisoptera, que compreende 9 famílias e apresenta a maior riqueza em espécies na ordem. Eles estão entre os insetos alados mais basais. Os mais antigos registros fósseis datam do Carbonífero médio, sendo, provavelmente, o grupo que apresenta o maior número de representantes extintos. A monofilia das subordens ainda é discutida, assim como as relações filogenéticas entre as famílias que as constituem. As características ultraestruturais dos espermatozoides tem se mostrado promissoras para análises filogenéticas em muitos grupos de insetos, porém trabalhos deste tipo ainda são inexistentes para Odonata. Assim, este trabalho teve como objetivo descrever a estrutura e a ultraestrutura dos espermatozoides de espécies de duas subordens de Odonata: Zygoptera e Anisoptera, buscando informações que possam auxiliar na compreensão da sistemática deste grupo de insetos. Para isso, espermatozoides de vesículas seminais e testículos de machos adultos de Ischnura fluviatilis (Zygoptera), Pantala flavescens, Tramea abdominalis e Micrathyria hesperis (Anisoptera) foram preparadas para microscopia de luz e eletrônica de transmissão. Os espermatozoides dessas espécies possuem algumas características semelhantes àquelas apresentadas pelos espermatozoides da maioria dos Pterygota. No entanto, algumas características diferenciais se destacam: ausência de perforatorium no acrossomo e de material paracristalino nos derivados mitocondriais; flagelo extremamente curto, possivelmente imóvel, com derivados mitocondriais pequenos nas espécies de Libellulidae (Anisoptera); e ausência de corpos acessórios e arranjo microtubular 9+9+0 nas espécies da subfamília Trameinae. A análise da ultraestrutura dos espermatozoides permitiu a diferenciação das duas subordens de Odonata, assim como das espécies das duas subfamílias de Libellulidae estudadas.The order Odonata includes about 5500 species and is currently divided into three suborders: Zygoptera, comprising 19 families; Anisozygoptera containing fossil taxa and only one living genus with two species, and Anisoptera, which comprises nine families and has the highest wealth species in order. They are among the most basal winged insects. The oldest fossil records of Odonata dating from the Middle Carboniferous, and probably is the group that presents the greatest number of representatives extinct. The monophyly of the suborders is still discussed as well as the phylogenetic relationships among families that constitute them. The ultrastructural features of the sperm has shown promise for phylogenetic analyzes in many insect groups, but such studies are still lacking for Odonata. Thus, this study aimed to describe the structure and ultrastructure of spermatozoa of species of Odonata suborders: Zygoptera and Anisoptera, searching for information that would assist in understanding the systematics of this group of insects. For this, sperm from seminal vesicles and testes of adult males of the Ischnura fluviatilis (Zygoptera), Pantala flavescens, Tramea abdominalis e Micrathyria hesperis (Anisoptera) were prepared for light and transmission electron microscopy. The sperm of these species have some characteristics similar to those presented by the sperm of most Pterygota. However, some differential characteristics stand out: lack of perforatorium in the acrosome and of paracrystalline material in the mitochondrial derivatives; flagellum very short, possibly immobile with small mitochondrial derivatives inspecies of Libellulidae (Anisoptera); and lack of accessories bodies and microtubule arrangement 9+9+0 in species of the Trameinae subfamily. The analysis of the ultrastructure of spermatozoa enabled the differentiation of the two suborders of Odonata, as well as, the species of two Libellulidae subfamilies studied

Cytogenetic data of Partamona peckolti (Hymenoptera, Apidae, Meliponini) by C banding and fluorochrome staining with DA/CMA3 and DA/DAPI

The stingless bees of the Partamona genus have been studied taxonomically, ecologically and behaviourally, but cytogenetic studies are still rare. The objective of this study was to obtain cytogenetic data to contribute to Partamona peckolti species characterization. Heterochromatin was localized in all chromosome pericentromeric regions but some blocks could be visualized on some large chromosomes arms. A large heterozygous DA-CMA3-positive band was observed on one large chromosome arm, but was completely absent when C banding was applied before fluorochrome staining, with only one small positive band being visualized. Sequential DA-CMA3-NOR staining of interphase nuclei provided coincident positive responses. This suggests that DA-CMA3-positive bands of P. peckolti correspond to nucleolar organizer regions, as previously confirmed for another Partamona species by FISH

Cytogenetic data of Partamona peckolti (Hymenoptera, Apidae, Meliponini) by C banding and fluorochrome staining with DA/CMA3 and DA/DAPI

The stingless bees of the Partamona genus have been studied taxonomically, ecologically and behaviourally, but cytogenetic studies are still rare. The objective of this study was to obtain cytogenetic data to contribute to Partamona peckolti species characterization. Heterochromatin was localized in all chromosome pericentromeric regions but some blocks could be visualized on some large chromosomes arms. A large heterozygous DA-CMA3-positive band was observed on one large chromosome arm, but was completely absent when C banding was applied before fluorochrome staining, with only one small positive band being visualized. Sequential DA-CMA3-NOR staining of interphase nuclei provided coincident positive responses. This suggests that DA-CMA3-positive bands of P. peckolti correspond to nucleolar organizer regions, as previously confirmed for another Partamona species by FISH