El tratamiento con 5azadC regula al alza el nivel de miR-375 y reprime la expresión de HPV16 E6

High-risk human papillomaviruses are the etiological agents of cervical cancer and HPV16 is the most oncogenic genotype. Immortalization and transformation of infected cells requires the overexpression of the two viral oncoproteins E6 and E7 following HPV DNA integration into the host cell genome. Integration often leads to the loss of the E2 open reading frame and the corresponding protein can no longer act as a transcriptional repressor on p97 promoter. Recently, it has been proposed that long control region methylation also contributes to the regulation of E6/E7 expression. To determine which epigenetic mechanism is involved in HPV16 early gene regulation, 5-aza-2?-deoxycytidine was used to demethylate Ca Ski and SiHa cell DNA. Decreased expression of E6 mRNA and protein levels was observed in both cell lines in an E2-independent manner. E6 repression was accompanied by neither a modification of the main cellular transcription factor expression involved in long control region regulation, nor by a modification of the E6 mRNA splicing pattern. In contrast, a pronounced upregulation of miR-375, known to destabilize HPV16 early viral mRNA, was observed. Finally, the use of miR-375 inhibitor definitively proved the involvement of miR-375 in E6 repression. These results highlight that cellular DNA methylation modulates HPV16 early gene expression and support a role for epigenetic events in high-risk HPV associated-carcinogenesis

Antiquity of cleptoparasitism among bees revealed by morphometric and phylogenetic analysis of a Paleocene fossil nomadine (Hymenoptera: Apidae)

peer reviewedCleptoparasitism is a way of life involving the theft of resources by one animal from another. This behavior occurs in many bee tribes but its origin and evolution remain obscure, particularly owing to the relative scarcity of bees in the fossil record. Hitherto, no fossil evidence has been previously recorded to trace the origin of cleptoparasitim among bees. In the current study, we present the first cleptoparasitic bee fossil, providing analyses of its taxonomic affinities and a complete description. The specimen happens to also be one of the earliest bee fossils, having been discovered in the spongo-diatomitic volcanic paleolake of Menat (Paleocene) in France. We employed geometric morphometrics of the forewing shape to assess the taxonomic affinities of the fossil with modern apoid tribes. Our data set included 979 specimens representing 50 tribes and 226 extant species. Based on linear and geometric morphometrics, we demonstrate that the fossil's forewing shape is similar to Apidae, and particularly to the tribe Epeolini (Nomadinae). The fossil is described as Paleoepeolus micheneri gen.n., sp.n. and provides the first direct evidence on the antiquity of cleptoparasitism among bees. This published work has been registered on Zoobank. URL: http://zoobank.org/References/BBBE2217-6CAE-48F9-851F-716B813DFEBF

DNA demethylation agent 5azadC downregulates HPV16 E6 expression in cervical cancer cell lines independently of TBX2 expression

HPV16 is the most carcinogenic human papillomavirus and causes >50% of cervical cancers, the majority of anal cancers and 30% of oropharyngeal squamous cell carcinomas. HPV carcinogenesis relies on the continuous expression of the two main viral oncoproteins E6 and E7 that target >150 cellular proteins. Among them, epigenetic modifiers, including DNA Methyl Transferases (DNMT), are dysregulated, promoting an aberrant methylation pattern in HPV-positive cancer cells. It has been previously reported that the treatment of HPV-positive cervical cancer cells with DNMT inhibitor 5-aza-2'-deoxycytidine (5azadC) caused the downregulation of E6 expression due to mRNA destabilization that was mediated by miR-375. Recently, the T-box transcription factor 2 (TBX2) has been demonstrated to repress HPV LCR activity. In the current study, the role of TBX2 in E6 repression was investigated in HPV16 cervical cancer cell lines following 5azadC treatment. A decrease of E6 expression was accompanied by p53 and p21 restoration. While TBX2 mRNA was upregulated in 5azadC-treated SiHa and Ca Ski cells, TBX2 protein was not detectable. Furthermore, the overexpression of TBX2 protein in cervical cancer cells did not allow the repression of E6 expression. The TBX2 transcription factor is therefore unlikely to be associated with the repression of E6 following 5azadC treatment of SiHa and Ca Ski cells. © 2020 Spandidos Publications. All rights reserved

Vespinae of Yunnan.

10 p. ; 26 cm. "April 19, 2011."In recent years, five new species of Vespinae have been described from Yunnan Province, China. A thorough assessment of these taxa, including study of color differences and compilation of measurements of specimens from six entomological collections, shows that the new taxa are merely variants of existing, nominal species. Thus, all five are synonymized here, as follows: Vespa hekouensis Dong and Wang, and Vespa maguanensis Dong = Vespa analis Fabricius; Vespula yulongensis Dong and Wang = Vespula flaviceps (Smith); Vespula nujiangensis Dong and Wang = Vespula orbata (du Buysson); and Vespula gongshanensis Dong = Vespula rufa (Linnaeus), all new synonymy. The synonymies bring the current number of vespine species recognized worldwide to 67

National records of 3000 European bee and hoverfly species: A contribution to pollinator conservation

peer reviewedPollinators play a crucial role in ecosystems globally, ensuring the seed production of most flowering plants. They are threatened by global changes and knowledge of their distribution at the national and continental levels is needed to implement efficient conservation actions, but this knowledge is still fragmented and/or difficult to access. As a step forward, we provide an updated list of around 3000 European bee and hoverfly species, reflecting their current distributional status at the national level (in the form of present, absent, regionally extinct, possibly extinct or non-native). This work was attainable by incorporating both published and unpublished data, as well as knowledge from a large set of taxonomists and ecologists in both groups. After providing the first National species lists for bees and hoverflies for many countries, we examine the current distributional patterns of these species and designate the countries with highest levels of species richness. We also show that many species are recorded in a single European country, highlighting the importance of articulating European and national conservation strategies. Finally, we discuss how the data provided here can be combined with future trait and Red List data to implement research that will further advance pollinator conservation

Thorax - 3D

Surface files (.ply) of the mesosoma (~thorax) from the CT-scan 3D models of the 22 specimens. These surface files were used to assess the landmark coordinates to quantify the shape of the mesosoma (~thorax). Raw CT-scan data are not deposited because too large, but can be accessed by contacting the author

Wasp waist and flight: convergent evolution in wasps reveals a link between wings and body shapes

International audienceInsect flight is made possible by different morphological structures: wings produce the lift, the thorax drives the wings' movements and the abdomen serves as a secondary control device. As such, the covariation of these structures could reflect functional constraints related to flight performances. This study examines evolutionary convergences in wasp body shapes to provide the first evidence for morphological integration among insect wings, thorax and abdomen. Shapes of the fore-and hindwings, thorax and petiole (connecting abdomen and thorax) of 22 Vespidae species were analyzed using computerized tomography and geometric morphometrics. Results show a clear relationship between petiole and wings or thorax shapes, but not between wings and thorax. Wasps with elongated bodies have pointed wings, both features thought to improve flight maneuverability. In contrast, stouter species have rounded wings, which may allow for higher flight speeds. These integration patterns suggest that multiple selective regimes on flight performance, some of them biased towards maneuverability or maximal speed, drove the morphological diversity in Vespidae. The results also suggest that wing shapes evolved under constraints related to the body type they have to lift. The abdomen morphology is thus another factor to take into account to understand the flight performance of insects.

Data from: Patriline differences reveal genetic influence on forewing size and shape in a yellowjacket wasp (Hymenoptera: Vespidae: Vespula flavopilosa Jacobson, 1978)

The wing venation is frequently used as a morphological marker to distinguish biological groups among insects. With geometric morphometrics, minute shape differences can be detected between closely related species or populations, making this technique useful for taxonomy. However, the direct influence of genetic differences on wing morphology has not been explored within colonies of social insects. Here, we show that the father’s genotype has a direct effect on wing morphology in colonies of social wasps. Using geometric morphometrics on the venation pattern, we found significant differences in wing size and shape between patrilines of yellowjackets, taking allometry and measurement error into account. The genetic influence on wing size accounted for a small part of the overall size variation, but venation shape was highly structured by the differences between patrilines. Overall, our results showed a strong genetic influence on wing morphology likely acting at multiple levels of venation pattern development. This confirmed the pertinence of this marker for taxonomic purposes and suggests this phenotype as a potentially useful marker for phylogenies. This also raises doubts about the strength of selective pressures on this phenotype, which highlights the need to understand better the role of wing venation shape in insect flight