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1.
Sci Rep ; 11(1): 16973, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417480

RESUMO

Providing clear and detailed morphological descriptions of endemic species in limited areas enables new knowledge of their biology and ecology to be obtained through citizen science. This information can be further used for their protection. Our study presents the first morphological description of the larvae of all three instars of Heterotemna tenuicornis (Brullé, 1836), an endemic species of the Canary Islands that, together with H. britoi García & Pérez, 1996 and H. figurata (Brullé, 1839), belongs to the peculiar genus Heterotemna Wollaston, 1864. Furthermore, we present the first sequences of two mitochondrial genes (COI, 16S) obtained from larval specimens, and cross reference them with sequences from an adult specimen. Phylogenetic analysis of molecular data placed the genus Heterotemna within the genus Silpha Linnaeus, 1758, suggesting paraphyly of Silpha. In our study, we underline the importance of using a combination of morphological description and molecular data, that can be used for barcoding developmental stages which could not otherwise be definitely associated.


Assuntos
Besouros/anatomia & histologia , Besouros/classificação , Filogenia , Animais , Teorema de Bayes , Besouros/genética , Besouros/ultraestrutura , Larva/anatomia & histologia , Larva/classificação , Larva/genética , Larva/ultraestrutura , Especificidade da Espécie
2.
Acta Trop ; 221: 106024, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34181874

RESUMO

The microtrichia of the labral fan primary rays, considered as the finest structure of the larval filter mechanism in Simuliidae, and the posterior proleg hooks, a structure used for substrate attachment, were describe using Scanning Electron Microscopy for the first time in 14 Neotropical species of black flies. Four patterns of primary rays microtrichia and two types of hooks barbs disposition were found. The present study provides new morphological information for Neotropical black fly species, compares it with previous information for worldwide species. Also, shows that the presence of posterior proleg hooks barbs is common among black fly species, that these barbs are not related with the larval habitat or with the primary ray microtrichia pattern, and that flow conditions may influence the last-instar larvae microtrichial patterns, at least in most of the Neotropical species studied here.


Assuntos
Simuliidae , Animais , Ecossistema , Larva/anatomia & histologia , Larva/ultraestrutura , Simuliidae/anatomia & histologia , Simuliidae/ultraestrutura
3.
Folia Parasitol (Praha) ; 682021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34152290

RESUMO

Based on light and electron microscopical studies, a new nematode parasite, Echinocephalus inserratus sp. n. (Spirurida: Gnathostomatidae), is described from the spiral valve of the broad cowtail stingray Pastinachus ater (Macleay) (Dasyatidae, Myliobatiformes) from off New Caledonia. The new species is morphologically and biometrically most similar to Echinocephalus overstreeti Deardorff et Ko, 1983, differing from it mainly in the absence of serrations on the posterior parts of pseudolabia and on interlabia, and in having a longer gubernaculum (150-299 µm long). Morphologically unidentifiable, mostly encapsulated larvae of Echinocephalus spp. were recorded from the following six species of teleost fishes collected in New Caledonian waters, serving as paratenic hosts: Perciformes: Acanthopagrus berda (Forsskål) (Sparidae) and Nemipterus furcosus (Valenciennes) (Nemipteridae); Tetraodontiformes: Abalistes stellatus (Anonymous), Pseudobalistes fuscus (Bloch et Schneider) (both Balistidae), Lagocephalus sceleratus (Gmelin) (Tetraodontidae) and Aluterus monoceros (Linnaeus) (Monacanthidae). Co-parasitising larvae of Ascarophis sp. and Hysterothylacium sp. were also collected from P. fuscus. All these findings represent new host and geographical records. A key to valid species of Echinocephalus Molin, 1858 is provided.


Assuntos
Doenças dos Peixes/epidemiologia , Interações Hospedeiro-Parasita , Rajidae , Infecções por Spirurida/veterinária , Thelazioidea/classificação , Animais , Feminino , Doenças dos Peixes/parasitologia , Larva/anatomia & histologia , Larva/classificação , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura/veterinária , Nova Caledônia/epidemiologia , Prevalência , Infecções por Spirurida/epidemiologia , Infecções por Spirurida/parasitologia , Thelazioidea/anatomia & histologia , Thelazioidea/crescimento & desenvolvimento , Thelazioidea/ultraestrutura
4.
J Cell Biol ; 220(9)2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34160561

RESUMO

Cells are 3D objects. Therefore, volume EM (vEM) is often crucial for correct interpretation of ultrastructural data. Today, scanning EM (SEM) methods such as focused ion beam (FIB)-SEM are frequently used for vEM analyses. While they allow automated data acquisition, precise targeting of volumes of interest within a large sample remains challenging. Here, we provide a workflow to target FIB-SEM acquisition of fluorescently labeled cells or subcellular structures with micrometer precision. The strategy relies on fluorescence preservation during sample preparation and targeted trimming guided by confocal maps of the fluorescence signal in the resin block. Laser branding is used to create landmarks on the block surface to position the FIB-SEM acquisition. Using this method, we acquired volumes of specific single cells within large tissues such as 3D cultures of mouse mammary gland organoids, tracheal terminal cells in Drosophila melanogaster larvae, and ovarian follicular cells in adult Drosophila, discovering ultrastructural details that could not be appreciated before.


Assuntos
Drosophila melanogaster/ultraestrutura , Células da Granulosa/ultraestrutura , Glândulas Mamárias Animais/ultraestrutura , Microscopia Eletrônica de Varredura/métodos , Coloração e Rotulagem/métodos , Células Tecais/ultraestrutura , Traqueia/ultraestrutura , Animais , Drosophila melanogaster/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Feminino , Expressão Gênica , Genes Reporter , Células da Granulosa/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Humanos , Larva/metabolismo , Larva/ultraestrutura , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Glândulas Mamárias Animais/metabolismo , Camundongos , Microscopia Eletrônica de Varredura/instrumentação , Organoides/metabolismo , Organoides/ultraestrutura , Análise de Célula Única/instrumentação , Análise de Célula Única/métodos , Células Tecais/metabolismo , Traqueia/metabolismo , Fluxo de Trabalho
5.
Parasitol Res ; 120(3): 899-910, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33432440

RESUMO

During their different life stages, parasites undergo remarkable morphological, physiological, and behavioral "metamorphoses" to meet the needs of their changing habitats. This is even true for ectoparasites, such as the monogeneans, which typically have a free-swimming larval stage (oncomiracidium) that seeks out and attaches to the external surfaces of fish where they mature. Before any obvious changes occur, there are ultrastructural differences in the oncomiracidium's outer surface that prepare it for a parasitic existence. The present findings suggest a distinct variation in timing of the switch from oncomiracidia epidermis to the syncytial structure of the adult tegument and so, to date, there are three such categories within the Monogenea: (1) Nuclei of both ciliated cells and interciliary cytoplasm are shed from the surface layer and the epidermis becomes a syncytial layer during the later stages of embryogenesis; (2) nuclei of both ciliated cells and interciliary syncytium remain distinct and the switch occurs later after the oncomiracidia hatch (as in the present study); and (3) the nuclei remain distinct in the ciliated epidermis but those of the interciliary epidermis are lost during embryonic development. Here we describe how the epidermis of the oncomiracidium of Discocotyle sagittata is differentiated into two regions, a ciliated cell layer and an interciliary, syncytial cytoplasm, both of which are nucleated. The interciliary syncytium extends in-between and underneath the ciliated cells and sometimes covers part of their apical surfaces, possibly the start of their shedding process. The presence of membranous whorls and pyknotic nuclei over the surface are indicative of membrane turnover suggesting that the switch in epidermis morphology is already initiated at this stage. The body tegument and associated putative sensory receptors of subadult and adult D. sagittata are similar to those in other monogeneans.


Assuntos
Epiderme/ultraestrutura , Doenças dos Peixes/parasitologia , Salmonidae/parasitologia , Trematódeos/ultraestrutura , Infecções por Trematódeos/veterinária , Animais , Núcleo Celular/ultraestrutura , Citoplasma/ultraestrutura , Epiderme/crescimento & desenvolvimento , Brânquias/parasitologia , Larva/ultraestrutura , Trematódeos/crescimento & desenvolvimento , Infecções por Trematódeos/parasitologia
6.
J Morphol ; 282(1): 115-126, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33078885

RESUMO

The genus Edalorhina consists of two species of small forest-floor frogs inhabiting the Amazon basin. The tadpole of Edalorhina perezi, the most widely distributed species, was previously described based on a single and early stage (Gosner 25) individual. Herein, we provide a description of the tadpole in Gosner stages 35-36 including internal morphology data (i.e., buccopharyngeal cavity and larval skeleton) based on samples from two populations from Ecuador. Edalorhina shares a generalized morphology with most members of its closely related taxa; however, it is distinguished from the other species by having an almost terminal oral disc. The presence of a dextral vent tube is considered a synapomorphy for the clade consisting of Edalorhina, Engystomops, and Physalaemus. Within this clade, the combination of two lingual papillae, a filiform median ridge, and the lack of buccal roof papillae are diagnostic of E. perezi and putative autapomorphies of Edalorhina. Chondrocranial anatomy provides characteristics, that is, presence of and uniquely shaped processus pseudopterygoideus and cartilago suprarostralis with corpora and alae joined by dorsal and ventral connections that readily differentiates the genus from other Leiuperinae.


Assuntos
Anuros/anatomia & histologia , Boca/anatomia & histologia , Crânio/anatomia & histologia , Animais , Brasil , Larva/anatomia & histologia , Larva/ultraestrutura , Boca/ultraestrutura , Filogenia , Crânio/ultraestrutura , Especificidade da Espécie
7.
J Morphol ; 282(1): 48-65, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33074574

RESUMO

Neocaridina davidi is a freshwater shrimp that originates from Taiwan and is commonly bred all over the word. Like all decapods, which develop indirectly, this species has pelagic larvae that may differ entirely in their morphology and habits from adult specimens. To fill a gap of knowledge about the developmental biology of freshwater shrimps we decided to document the 3D-localization of the midgut inside the body cavity of larval stages of N. davidi using X-ray microtomography, and to describe all structural and ultrastructural changes of the midgut epithelium (intestine and hepatopancreas) which occur during postembryonic development of N. davidi using light and transmission electron microscopy. We laid emphasis on stem cell functioning and cell death processes connected with differentiation. Our study revealed that while the intestine in both larval stages of N. davidi has the form of a fully developed organ, which resembles that of adult specimens, the hepatopancreas undergoes elongation and differentiation. E-cells, which are midgut stem cells, due to their proliferation and differentiation are responsible for the above-mentioned processes. Our study revealed that apoptosis is a common process in both larval stages of N. davidi in the intestine and proximal region of the hepatopancreas. In zoea III, autophagy as a survival factor is activated in order to protect cells against their death. However, when there are too many autophagic structures in epithelial cells, necrosis as passive cell death is activated. The presence of all types of cell death in the midgut in the zoea III stage confirms that this part of the digestive tract is fully developed and functional. Here, we present the first description of apoptosis, autophagy and necrosis in the digestive system of larval stages of Malacostraca and present the first description of their hepatopancreas elongation and differentiation due to midgut stem cell functioning.


Assuntos
Diferenciação Celular , Decápodes/crescimento & desenvolvimento , Água Doce , Trato Gastrointestinal/citologia , Crescimento e Desenvolvimento , Animais , Apoptose , Decápodes/citologia , Decápodes/ultraestrutura , Células Epiteliais/citologia , Hepatopâncreas/anatomia & histologia , Hepatopâncreas/citologia , Hepatopâncreas/ultraestrutura , Junções Intercelulares/metabolismo , Larva/citologia , Larva/crescimento & desenvolvimento , Larva/ultraestrutura
8.
Ticks Tick Borne Dis ; 12(1): 101572, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33068841

RESUMO

Females, nymphs, and larvae of Ixodes silvanus n. sp. collected from birds and from the vegetation in northwestern Argentina (Yungas Phytogeographic Province) are described herein. The new species belongs to the subgenus Trichotoixodes (Acari: Ixodidae). The female is diagnosed by a combination of the following characters: scutum with setae moderately long and more numerous in central field, fewer and moderately long setae on lateral fields, and inconspicuous setae in anterior field; basis capituli subtriangular dorsally; porose areas large and irregular in shape, lacking distinct margins; auriculae with straight edges diverging posterolaterally and ending with small blunt processes; hypostome narrow and pointed with dental formula 4/4 in the anterior third, then 3/3 and 2/2 near the base; coxae I with two spurs, sub-equal in size, internal slightly slimmer than external. The nymph is diagnosed by notum with numerous and long setae, ventral surface covered by numerous whitish setae, scutum with short scapulae and few and shallow punctations, setae on scutum few, short and irregularly distributed, basis capituli sub-triangular dorsally with posterior margin straight, cornua large and directed postero-laterally, auriculae large and projected laterally, lateral margin of basis capituli above auriculae with a lateral and triangular projection, hypostome pointed with dental formula 3/3 in the anterior third and then 2/2, and coxa I with two short, sub-equal, triangular spurs. The diagnostic characters of the larva are: basis capituli dorsally sub-triangular with lateral angles acute and posterior margin straight, auriculae as large triangular lateral projections, hypostome with apex bluntly pointed and dental formula 3/3 in the anterior third and then 2/2, coxa I with two short, sub-equal, triangular spurs, and pattern of dorsal and ventral body setae. This new species is phylogenetically related to Ixodes brunneus, Ixodes turdus and Ixodes frontalis, and the principal hosts for all its parasitic stages are birds.


Assuntos
Ixodes/anatomia & histologia , Ixodes/classificação , Animais , Argentina , DNA Espaçador Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , Ixodes/crescimento & desenvolvimento , Ixodes/ultraestrutura , Larva/anatomia & histologia , Larva/classificação , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Microscopia , Microscopia Eletrônica de Varredura , Ninfa/anatomia & histologia , Ninfa/classificação , Ninfa/crescimento & desenvolvimento , Ninfa/ultraestrutura , Filogenia , RNA Ribossômico 16S/análise
9.
Acta Trop ; 213: 105732, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33188750

RESUMO

Blastospores or conidia (formulated or not) of entomopathogenic fungi were assessed against Aedes aegypti larvae. Larvae (L2) were exposed to 105, 106, 107, and 108 propagules mL-1 water suspension. Mineral oil at 0.1%, 0.5%, or 1.0% (v/v) was employed to observe the effect on larval survival. The 0.1% mineral oil did not affect larval survival. Accordingly, 107 propagules mL-1 and 0.1% mineral oil were used to prepare all fungal emulsions. The fungal suspension or formulation was prepared as follows: 107 propagules mL-1 on 0.03% TweenⓇ 80 (v/v) aqueous solution or 107 propagules mL-1 on 0.03% TweenⓇ 80 plus 0.1% mineral oil; larval survival rates were evaluated for 7 days, and median survival time (S50) was also determined. The presence of fungi in larvae was examined both histologically and by scanning electron microscopy 24 h or 48 h after exposure. To evaluate the larval growth, larvae were exposed to 107 propagules mL-1 for 48 hours and their length measured using a digital caliper. Here, propagules had similar results in reducing the larvae survival rate and time. The treatment with Beauveria bassiana s.l. at 108 propagules mL-1 or with Metarhizium anisopliae s.l. at 108 blastopores mL-1 reduced the larval survival time to two days. M. anisopliae s.l. at 108 conidia mL-1 reduced the survival time to three days. The survival time of larvae submitted to the other treatments ranged from 6 days to over 7 days. M. anisopliae s.l. or B. bassiana s.l. oil-in-water emulsions at 107 propagules mL-1 yielded better results than the water suspensions, the larvae survival rate was 2 days for both propagules in oil-in-water emulsion. Larvae exposed to blastospores from both isolates or M. anisopliae conidia were longer than in the other treatments. Scanning electron microscopy and histology analyzes found fungi predominantly in the gut, mouthparts, and perispiracular lobes of larvae. Formulated fungus yielded better results than the aqueous suspensions for control of mosquito larvae. Thus, for the first time, the effect of mineral oil on the fungal interaction on A. aegypti larvae was observed as well as the effect of entomopathogenic fungi in the growth of larvae, supporting the search for strategies to control this arthropod.


Assuntos
Aedes/microbiologia , Beauveria , Metarhizium , Controle Biológico de Vetores , Aedes/crescimento & desenvolvimento , Aedes/ultraestrutura , Animais , Beauveria/fisiologia , Interações entre Hospedeiro e Microrganismos , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/ultraestrutura , Metarhizium/fisiologia , Microscopia Eletrônica de Varredura , Óleo Mineral , Esporos Fúngicos/fisiologia
10.
J Morphol ; 282(3): 329-354, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33368492

RESUMO

Sea spiders (Pycnogonida) are a small group of arthropods, sister to other chelicerates. They have an unusual adult bauplan, oligosegmented larvae, and a protracted postembryonic development. Pycnogonum litorale (Strøm, 1762) is an uncommonly long-lived sea spider with a distinctive protonymphon and adult anatomy. Although it was described ~250 years ago, little is known about its internal organization and development. We examined the anamorphic and early epimorphic development of this species using histology, light microscopy, and SEM, and provide the first comprehensive anatomical study of its many instars. Postembryonic development of P. litorale includes transformations typical of pycnogonids: reorganization of the larval organs (digestive, nervous, secretory), formation of the abdomen, trunk segments (+ appendages), primary body cavity and reproductive system. Specific traits include the accelerated articulation of the walking legs, formation of the subesophageal and posterior synganglia, and the system of twin midgut diverticula. In addition, P. litorale simultaneously lose the spinning apparatus and all larval appendages. We found that developmental changes occur in synchrony with changes in ecology and food sources. The transition from the anamorphic to the epimorphic period in particular is marked by considerable anatomical and lifestyle shifts. HIGHLIGHTS: Postembryonic development of P. litorale includes numerous anamorphic and epimorphic stages. The instars acquire abdomen, trunk segments, body cavity, and gonads, while losing all larval appendages. Developmental changes are synchronized with changes in lifestyle and food sources.


Assuntos
Artrópodes/anatomia & histologia , Artrópodes/crescimento & desenvolvimento , Crescimento e Desenvolvimento , Animais , Artrópodes/ultraestrutura , Feminino , Larva/anatomia & histologia , Larva/ultraestrutura , Masculino , Reprodução/fisiologia
11.
Arthropod Struct Dev ; 60: 101000, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33137554

RESUMO

The larvae of the lacewing Chrysoperla externa are important predators with the potential to be used in the biological control in agriculture. Although some studies provide important data on the gut morphology in lacewings, they are limited to few species. This study describes the anatomy and histology of the alimentary canal in the predatory larvae and herbivorous adult of C. externa. In larvae, the crop is the larger part of the foregut and it is connected to the midgut by the stomodeal valve. The midgut is an enlarged sac-like organ. At the mid-hindgut transition, there are eight Malpighian tubules. The hindgut is a non-functional vestigial region in the larvae. In adults, the crop has a diverticulum associated with large tracheal trunks, a conic proventriculus with sclerotized lips followed by an elongated tubular midgut. Histological analyses of larval and adult midgut show the presence of a single-layered epithelium with columnar cells with well-developed brush border, nests of regenerative cells, and a peritrophic matrix lining the midgut lumen. The hindgut in adults has an epithelium with cubic cells lined by a thin cuticular intima and rectal pads in the rectum. These data are discussed in comparison with the digestive tract in other Chrysopidae.


Assuntos
Holometábolos/anatomia & histologia , Animais , Sistema Digestório/anatomia & histologia , Sistema Digestório/crescimento & desenvolvimento , Sistema Digestório/ultraestrutura , Feminino , Holometábolos/crescimento & desenvolvimento , Holometábolos/ultraestrutura , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Masculino , Microscopia , Microscopia Eletrônica de Varredura
12.
Microsc Res Tech ; 84(2): 368-375, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32946130

RESUMO

Cetoniinae is one of the showiest scarab groups, exhibiting bright-metallic body colors, and usually attract great attention from entomologists and amateur collectors. Larvae of Cetoniinae show dramatically diversity on morphology and living habits. Although being considered one of the best-studied groups of Scarabaeidae, larvae have been described for less than 5% species to the known Cetoniinae. In this study, the final instar larva of Lasiotrichius succinctus hananoi was described using scanning electron microscopy. The larvae are peculiar for bearing a haptomeral process dividing 10 spines into two groups: six on the left side, four on the right side, different from the previous descriptions on L. succinctus (Pallas, 1781). The morphological differences under SEM imply the further requirement of taxonomic revision in Lasiotrichius. Both advantage and disadvantage of SEM utilizing in larval descriptions were briefly discussed.


Assuntos
Besouros/anatomia & histologia , Besouros/ultraestrutura , Microscopia Eletrônica de Varredura , Animais , Larva/anatomia & histologia , Larva/ultraestrutura
13.
Sci Rep ; 10(1): 18934, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33144603

RESUMO

Amphibians are models for studying applied ecological issues such as habitat loss, pollution, disease, and global climate change due to their sensitivity and vulnerability to changes in the environment. Developmental series of amphibians are informative about their biology, and X-ray based 3D reconstruction holds promise for quantifying morphological changes during growth-some with a direct impact on the possibility of an experimental investigation on several of the ecological topics listed above. However, 3D resolution and discrimination of their soft tissues have been difficult with traditional X-ray computed tomography, without time-consuming contrast staining. Tomographic data were initially performed (pre-processing and reconstruction) using the open-source software tool SYRMEP Tomo Project. Data processing and analysis of the reconstructed tomography volumes were conducted using the segmentation semi-automatic settings of the software Avizo Fire 8, which provide information about each investigated tissues, organs or bone elements. Hence, volumetric analyses were carried out to quantify the development of structures in different tadpole developmental stages. Our work shows that synchrotron X-ray microtomography using phase-contrast mode resolves the edges of the internal tissues (as well as overall tadpole morphology), facilitating the segmentation of the investigated tissues. Reconstruction algorithms and segmentation software played an important role in the qualitative and quantitative analysis of each target structure of the Thoropa miliaris tadpole at different stages of development, providing information on volume, shape and length. The use of the synchrotron X-ray microtomography setup of the SYRMEP beamline of Elettra Synchrotron, in phase-contrast mode, allows access to volumetric data for bone formation, eye development, nervous system and notochordal changes during the development (ontogeny) of tadpoles of a cycloramphid frog Thoropa miliaris. As key elements in the normal development of these and any other frog tadpole, the application of such a comparative ontogenetic study, may hold interest to researchers in experimental and environmental disciplines.


Assuntos
Anuros/crescimento & desenvolvimento , Larva/ultraestrutura , Microtomografia por Raio-X/veterinária , Algoritmos , Animais , Processamento de Imagem Assistida por Computador , Larva/crescimento & desenvolvimento , Síncrotrons
14.
PLoS One ; 15(11): e0242163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33180853

RESUMO

We describe the immature stages of Migonemyia migonei, which is the vector of Leishmania (Viannia) braziliensis, the etiological agent of cutaneous leishmaniasis in South America, and a putative vector of Leishmania infantum chagasi. Scanning Electron Microscopy (SEM) was used to refine the description of the structures of the egg, all instar larvae, and the pupa. The eggs have polygonal cells on the egg exochorion, and differences between larval and pupal chaetotaxy have been highlighted. Different sensillary subtypes-trichoidea, basiconica, coelonica and campanoformia-were observed in the larval stages. The results presented herein contribute to the taxonomy of Mg. migonei and may contribute to future studies on the phylogeny of this important vector species.


Assuntos
Dípteros/ultraestrutura , Insetos Vetores/ultraestrutura , Animais , Dípteros/crescimento & desenvolvimento , Dípteros/parasitologia , Feminino , Insetos Vetores/crescimento & desenvolvimento , Insetos Vetores/parasitologia , Larva/ultraestrutura , Leishmania infantum/patogenicidade , Masculino , Microscopia Eletrônica de Varredura , Óvulo/ultraestrutura , Pupa/ultraestrutura
15.
Sci Rep ; 10(1): 17916, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087765

RESUMO

Ciona robusta (Ciona intestinalis type A), a model organism for biological studies, belongs to ascidians, the main class of tunicates, which are the closest relatives of vertebrates. In Ciona, a project on the ontology of both development and anatomy is ongoing for several years. Its goal is to standardize a resource relating each anatomical structure to developmental stages. Today, the ontology is codified until the hatching larva stage. Here, we present its extension throughout the swimming larva stages, the metamorphosis, until the juvenile stages. For standardizing the developmental ontology, we acquired different time-lapse movies, confocal microscope images and histological serial section images for each developmental event from the hatching larva stage (17.5 h post fertilization) to the juvenile stage (7 days post fertilization). Combining these data, we defined 12 new distinct developmental stages (from Stage 26 to Stage 37), in addition to the previously defined 26 stages, referred to embryonic development. The new stages were grouped into four Periods named: Adhesion, Tail Absorption, Body Axis Rotation, and Juvenile. To build the anatomical ontology, 203 anatomical entities were identified, defined according to the literature, and annotated, taking advantage from the high resolution and the complementary information obtained from confocal microscopy and histology. The ontology describes the anatomical entities in hierarchical levels, from the cell level (cell lineage) to the tissue/organ level. Comparing the number of entities during development, we found two rounds on entity increase: in addition to the one occurring after fertilization, there is a second one during the Body Axis Rotation Period, when juvenile structures appear. Vice versa, one-third of anatomical entities associated with the embryo/larval life were significantly reduced at the beginning of metamorphosis. Data was finally integrated within the web-based resource "TunicAnatO", which includes a number of anatomical images and a dictionary with synonyms. This ontology will allow the standardization of data underpinning an accurate annotation of gene expression and the comprehension of mechanisms of differentiation. It will help in understanding the emergence of elaborated structures during both embryogenesis and metamorphosis, shedding light on tissue degeneration and differentiation occurring at metamorphosis.


Assuntos
Desenvolvimento Embrionário/fisiologia , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Metamorfose Biológica/fisiologia , Urocordados/anatomia & histologia , Urocordados/crescimento & desenvolvimento , Animais , Diferenciação Celular , Larva/citologia , Larva/ultraestrutura , Microscopia Confocal , Urocordados/embriologia , Urocordados/ultraestrutura
16.
J Parasitol ; 106(5): 663-669, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33079998

RESUMO

Ectoparasites were collected from Eptesicus hottentotus, the long-tailed serotine bat, caught in Namibia as part of an ecological study. Larvae of Argas transgariepinus, a blood-feeding ectoparasite of bats in Africa, were removed from 3 of 18 bats. We present scanning electron microscope images of unengorged larvae. As with other ectoparasites, this bat tick might transmit pathogens such as Borrelia and Rickettsia to their hosts as has been reported for bat ticks in Europe and North America. We screened 3 pools (25 total) of larvae of A. transgariepinus removed from the long-tailed serotine bat Eptesicus hottentotus caught in Namibia. Two microbes of unknown pathogenicity, including Rickettsia hoogstraalii, a spotted fever group pathogen, and a Rickettsiella sp. were detected by molecular techniques.


Assuntos
Argas/microbiologia , Quirópteros/parasitologia , Coxiellaceae/isolamento & purificação , Infecções por Rickettsia/transmissão , Rickettsia/isolamento & purificação , Infestações por Carrapato/veterinária , Animais , Argas/ultraestrutura , Infecções por Borrelia/transmissão , Coxiella/genética , Coxiella/isolamento & purificação , Coxiellaceae/genética , DNA Bacteriano/análise , Feminino , Larva/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura/veterinária , Namíbia , Rickettsia/genética , Infestações por Carrapato/parasitologia
17.
PLoS One ; 15(10): e0240223, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33052930

RESUMO

The Aedes aegypti mosquito plays an important role in the spread of diseases, including epidemic ones, such as dengue fever, Zika virus disease, yellow fever, and chikungunya disease. To control the population of Ae.aegypti, we transferred an HR3 RNAi fragment into the microalgae Chlamydomonas, which serves as food for Ae.aegypti larvae. Results showed that the HR3 RNAi transgenic algal strains were lethal to Ae.aegypti. The integumentary system of larvae fed with HR3 RNAi transgenic algal strains was severely damaged. Muscles of the larvae were unevenly distributed and disordered, and their midgut showed disintegration of the intestinal cavity. RNA-Seq results demonstrated that on the 4th day of inoculation with the transgenic algae, the abundance of early expressed genes in the 20E signal transduction pathway of larvae fed with the HR3 RNAi transgenic algal strain significantly reduced. These genes include E74, E75, E93, and 20E receptor complex EcR/USP and FTZ-F1 gene regulated by HR3. In later experiments, a scale test of 300 Ae.aegypti eggs per group was carried out for 30 days, and the survival rate of Ae.aegypti fed with the HR3 RNAi transgenic strain was only 1.3%. These results indicate that the HR3 RNAi transgenic strain exerts obvious insecticidal effect.


Assuntos
Aedes , Chlamydomonas/genética , Proteínas de Insetos/genética , Controle de Mosquitos , Mosquitos Vetores , Controle Biológico de Vetores , Interferência de RNA , Receptores Citoplasmáticos e Nucleares/genética , Animais , Biologia Computacional , Feminino , Inseticidas , Larva/genética , Larva/ultraestrutura , Masculino , Microrganismos Geneticamente Modificados
18.
J Morphol ; 281(10): 1210-1222, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32865277

RESUMO

Larvae of the burrowing water beetle family Noteridae are distributed worldwide and are often abundant in a broad range of aquatic habitats, playing an important role in structuring freshwater communities, yet they have remained among the most poorly studied groups of aquatic beetles. Studies on sensillar equipment of aquatic insect larvae are largely lacking, despite their potential use in phylogeny and biometric identification methods. In this article, the external morphology and distribution of sensilla on the head appendages of first instar larvae of selected genera of Noteridae were examined using scanning electron microscopy. Seven main types were distinguished based on their morphological structure: basiconica (3 subtypes), campaniformia (2 subtypes), chaetica (7 subtypes), coeloconica (6 subtypes), coniform complex (2 subtypes), placodea, and styloconica (3 subtypes). The apex of the labial palpus was found to be the most variable and informative region in regard to the number, relative position, and topology of sensilla. Fingerprint models were, therefore, generated for this region in each of the studied genera, allowing their identification.


Assuntos
Biometria , Besouros/anatomia & histologia , Besouros/classificação , Sensilas/anatomia & histologia , Animais , Antenas de Artrópodes/ultraestrutura , Besouros/ultraestrutura , Feminino , Cabeça , Larva/anatomia & histologia , Larva/ultraestrutura , Masculino , Filogenia , Sensilas/ultraestrutura
19.
PLoS One ; 15(9): e0236653, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956411

RESUMO

Symbiosis can facilitate the development of specialized organs in the host body to maintain relationships with beneficial microorganisms. To understand the developmental and genetic mechanisms by which such organs develop, it is critical to first investigate the morphology and developmental timing of these structures during the onset of host development. We utilized micro-computed tomography (µCT) to describe the morphology and development of mycangia, a specialized organ, in the Asian ambrosia beetle species Euwallacea validus which maintains a mutualistic relationship with the Ascomycete fungus, Fusarium oligoseptatum. We scanned animals in larval, pupal and adult life stages and identified that mycangia develop during the late pupal stage. Here we reconcile preliminary evidence and provide additional morphological data for a second paired set of structures, including the superior, medial mycangia and an inferior, lateral pair of pouch-like structures, in both late-stage pupae and adult female beetles. Furthermore, we report the possible development of rudimentary, or partially developed pairs of medial mycangia in adult male beetles which has never been reported for any male Xyleborini. Our results illustrate the validity of µCT in observing soft tissues and the complex nature of mycangia morphology and development.


Assuntos
Besouros/crescimento & desenvolvimento , Besouros/ultraestrutura , Animais , Besouros/anatomia & histologia , Feminino , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Masculino , Pupa/anatomia & histologia , Pupa/crescimento & desenvolvimento , Pupa/ultraestrutura , Caracteres Sexuais , Microtomografia por Raio-X
20.
Sci Rep ; 10(1): 14574, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32884008

RESUMO

Energy dispersive X-ray spectroscopy (EDS) carried out alongside scanning electron microscopy (SEM) is a common technique for elemental analysis. To investigate "wet" biological specimens, complex pre-treatments are required to stabilize them under the high vacuum conditions of high-resolution SEM. These often produce unwanted artifacts. We have previously reported that the polymerization of natural surface substances on organisms by the electron beam of the SEM setup or by plasma irradiation causes a nano-scale layer to form-called a "NanoSuit"-that can act as a barrier and keep organisms alive and hydrated in a field-emission SEM system. In the study reported herein, we examined the suitability of the NanoSuit method for elemental analyses of biological specimens by EDS. We compared experimental results for living Drosophila larvae and Aloe arborescens specimens prepared by the NanoSuit method and by conventional fixation. The NanoSuit method allowed accurate detection of the elemental compositions at high resolution. By contrast, specimens prepared by the conventional fixation method displayed additional EDS signals corresponding to the elements in the chemicals involved in the fixation process. Our results demonstrate that the NanoSuit method is useful for studying hydrous samples via EDS and SEM, particularly in biological sciences.


Assuntos
Drosophila melanogaster/metabolismo , Elementos Químicos , Larva/metabolismo , Microscopia Eletrônica de Varredura/métodos , Nanotecnologia/métodos , Polímeros/química , Espectrometria por Raios X/métodos , Animais , Drosophila melanogaster/ultraestrutura , Larva/ultraestrutura , Vácuo
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