Structural and ultrastructural characterization of male reproductive tracts and spermatozoa in fig wasps of the genus Pegoscapus (Hymenoptera, Chalcidoidea)

The three Pegoscapus species present the same internal reproductive tract features comprising testes with a single testicular tubule, seminal vesicles, vasa deferentia, accessory glands and an ejaculatory duct. The seminal vesicle shows two morphologically distinct portions although they do not resemble the separate chambers found in other Chalcidoidea. The anterior portion of the seminal vesicle shows a prominent epithelium and stores the mature spermatozoa, while the posterior region is formed by a thicker muscular sheath that participates on ejaculation. The sexual maturation in Pegoscapus is achieved at emergence, when the testicular degeneration occurs. The spermatozoa of Pegoscapus reveal a basic structure similar to that of other Chalcidoidea. In Pegoscapus sp1. and Pegoscapus sp2. they present the same features, whereas Pegoscapus tonduzi comprises some different characteristics. It measures approximately 160 μm in Pegoscapus sp1. and Pegoscapus sp2., while in P. tonduzi the spermatozoa measure about 360 μm. The extracellular sheath thickness is another difference among the species. While Pegoscapus sp1. and Pegoscapus sp2. show a thick extracellular sheath, in P. tonduzi this sheath is very thin resulting in a large space intervening between the extracellular sheath and the nucleus. Despite these differences, the three species analyzed share some characteristics that allow the establishment of an identity to the spermatozoon of the genus Pegoscapus: the seminal vesicle not divided in chambers; the absence of acrosomal structures in the spermatozoa; the length of the extracellular sheath; the central microtubules being the firsts to terminate in the sequence of microtubular cutoff at the final axonemal portion

Morphology of the male reproductive system and spermiogenesis in Hypanthidium foveolatum (Alfken, 1930) (Hymenoptera : Apidae : Megachilinae)

The morphological aspects of male reproductive tract, spermiogenesis and spermatozoa are typical for each species and reflect its evolution, establishing a unique source of characters, which has been used to help solve phylogenetic problems. In Hypanthidium foveolatum the reproductive tract is composed of the testes comprising 28 testicular tubules, deferent ducts, seminal vesicles, accessory glands and an ejaculatory duct. The differentiation of spermatids occurs within cysts of up to 128 germ line cells each one. During the early spermatid phase, the nucleus resembles that of somatic cells. There follows a gradual chromatin condensation with an increase in nuclear electron density. In the spermatozoon, the nucleus contains heterogeneous chromatin with a loose appearance. The acrosome, shaped with the active participation of the Golgi complex, shows an electron-dense perforatorium involved by four electron-lucent acrosomal vesicle projections. The sperm tail presents an axoneme with a 9 + 9 + 2 microtubule pattern and two mitochondrial derivatives, which appear with different sizes. A dense crystalloid is formed initially in the mitochondrial matrix of the large derivative. The mitochondrial derivatives’ differentiation occurs concomitantly with an axoneme outgrowth. The centriolar adjunct is observed near the axoneme, anterior to the smaller mithocondrial derivative and exhibits an approximately triangular shape in cross-sections. Microtubules were observed around the head region and flagellar components during spermiogenesis

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project

In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory

Characterization of the male reproductive tract and spermatozoa in wasps of the genus Pegoscapus (Hymenoptera, Chalcidoidea)

Orientador: Sonia Nair BaoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: As vespas da família Agaonidae, são as únicas entre as vespas de figo que polinizam as figueiras possuindo uma identidade espécie-específica em relação à planta. A relação de polinização das vespas do figo com as figueiras é de um mutualismo obrigatório: a planta necessita das vespas para a dispersão do pólen e para a polinização e, por sua vez, as vespas são completamente dependentes dos figos para que seu ciclo de vida se complete. Essa interação representa talvez o melhor exemplo de mutualismo integrado à polinização que se tem conhecimento. Trabalhos de sistemática com estas vespas são de fundamental importância para estudos de ecologia e evolução. Inúmeros estudos têm demonstrado que a estrutura e a ultra-estrutura do trato reprodutor masculino e dos espermatozóides em Hymenoptera apresentam variações suficientes para gerar caracteres adicionais para as análises cladísticas. Sendo assim, análises estruturais e ultra-estruturais foram realizadas a fim de descrever a morfologia do trato reprodutor masculino e dos espermatozóides em três espécies do gênero Pegoscapus. Para tanto, utilizamos as seguintes metodologias: microscopia de luz utilizando campo claro, contraste de fase e fluorescência para DAPI; microscopia eletrônica de transmissão convencional e citoquímica com E-PTA e microscopia eletrônica de varredura. As espécies de Pegoscapus apresentaram o trato reprodutivo interno e a estrutura básica dos espermatozóides similares a outros Chalcidoidea. Os espermatozóides de duas espécies demonstraram as mesmas características enquanto a terceira apresentou diferenças em relação ao comprimento e à espessura da camada extracelular. Além dessas diferenças, todas as espécies analisadas compartilharam de algumas características: vesícula seminal sem divisões de câmaras; ausência de estruturas acrossomais no espermatozóide; comprimento da camada extracelular e os microtúbulos centrais sendo os primeiros a terminar na seqüência de desmontagem do axonema em sua porção final. Essas características permitem o estabelecimento de um padrão para o gênero Pegoscapus que será útil para futuros estudos filogenéticos do grupo ChalcidoideaAbstract: The wasps of the family Agaonidae, are the only among fig wasps which pollinate figs, they are also species-specific to their host. The relationship of the pollinating fig wasps with their host fig tree is an obligate mutualism: the tree relies on the wasps for pollen dispersal and pollination, and in turn the wasps are completely dependent on the fig for the completion of their life cycle. This interaction represents perhaps the most tightly integrated pollination mutualism that is known. Systematic works on these wasps are of fundamental importance to ecological and evolutionary studies. Numerous investigations have demonstrated that structure and ultrastructure of the male reproductive tract and spermatozoa in Hymenoptera furnish sufficient variations to provide additional characters for cladistic analysis. Thus, structural and ultrastructural studies were carried out to describe the morphology of the male reproductive tract and the spermatozoa in three species of the genus Pegoscapus. For this study, we employed the methods: light microscopy using bright-field, phase-contrast and DAPI fluorescence; transmission electron microscopy with conventional preparations and cytochemistry (E-PTA) and scanning electron microscopy. Pegoscapus species presented the internal reproductive tract features and the basic sperm structure similar to that of other Chalcidoidea. The spermatozoa of two Pegoscapus species showed the same features while the other presented differences in length and in extracellular sheath thickness. Besides these differences, all species analyzed share some characteristics: the seminal vesicle not divided in chambers; the absence of acrosomal structures in the spermatozoa; the length of the extracellular sheath and the central microtubules being the firsts to terminate in the sequence of microtubular cutoff at the final axonemal portion. These characteristics permit the establishment of a pattern for the genus Pegoscapus that will be useful for phylogenetic studies in ChalcidoideaMestradoBiologia CelularDoutor em Biologia Celular e Estrutura

Anurans from preserved and disturbed areas of Atlantic Forest in the region of Etá Farm, municipality of Sete Barras, state of São Paulo, Brazil

<div><p>Abstract: We provide information on the diversity and natural history of anurans from preserved and disturbed habitats in the region of Etá Farm, municipality of Sete Barras, state of São Paulo, Brazil. The region is covered by rainforest and plantations of banana and peach palm. From April, 2013 to March, 2014 we sampled amphibians mainly with pitfall traps with drift fences and visual and auditory surveys. A total of 9813 individuals of 36 species of anurans from nine families were recorded in this study. A larger number of species was found in forests (29 species), followed by peach palm plantations (21 species), and banana plantations (17 species). The areas of peach palm plantation and forests showed the greatest similarity in species composition. The vegetation type with the highest number of exclusive species was the forest, whereas only four species were exclusive of the peach palm plantation, and none was exclusive of the banana plantation. Species accumulation curves indicated that our sampling effort was not enough to sample all the species that occur in the region. Our results reinforce the importance of forested habitats for the maintenance of anuran diversity in the Atlantic forest. The preservation of large fragments of forest in the region of Etá Farm is necessary to preserve the diverse amphibian fauna of this region.</p></div

Occurrence of Ochoterenella digiticauda (Nematoda: Onchocercidae) infecting the gladiator frog Hypsiboas lundii (Anura: Hylidae) in Brazil

Hypsiboas lundii is a gladiator frog endemic to the Cerrado of central and southeastern Brazil. This species in reproductive period inhabits streams in primary and secondary forests. Despite its wide distribution, the helminth fauna of this species has not been studied yet. Fourteen individuals were sampled and examined for helminth parasites. Three males were infected with Ochoterenella digiticauda (Onchocercidade). The mean abundance and mean intensity of infection were 0.7 ± 0.5 and 3.3 ± 1.9, respectively. All parasites were found in the body cavity of H. lundii, which represents a new host record for O. digiticauda