40 research outputs found
RNAi Trigger Delivery into Anopheles gambiae Pupae
Citation: Regna, K., Harrison, R. M., Heyse, S. A., Chiles, T. C., Michel, K., & Muskavitch, M. A. T. (2016). RNAi Trigger Delivery into Anopheles gambiae Pupae. Jove-Journal of Visualized Experiments(109), 9. doi:10.3791/53738RNA interference (RNAi), a naturally occurring phenomenon in eukaryotic organisms, is an extremely valuable tool that can be utilized in the laboratory for functional genomic studies. The ability to knockdown individual genes selectively via this reverse genetic technique has allowed many researchers to rapidly uncover the biological roles of numerous genes within many organisms, by evaluation of loss-of-function phenotypes. In the major human malaria vector Anopheles gambiae, the predominant method used to reduce the function of targeted genes involves injection of double-stranded (dsRNA) into the hemocoel of the adult mosquito. While this method has been successful, gene knockdown in adults excludes the functional assessment of genes that are expressed and potentially play roles during pre-adult stages, as well as genes that are expressed in limited numbers of cells in adult mosquitoes. We describe a method for the injection of Serine Protease Inhibitor 2 (SRPN2) dsRNA during the early pupal stage and validate SRPN2 protein knockdown by observing decreased target protein levels and the formation of melanotic pseudo-tumors in SRPN2 knockdown adult mosquitoes. This evident phenotype has been described previously for adult stage knockdown of SRPN2 function, and we have recapitulated this adult phenotype by SRPN2 knockdown initiated during pupal development. When used in conjunction with a dye-labeled dsRNA solution, this technique enables easy visualization by simple light microscopy of injection quality and distribution of dsRNA in the hemocoel
The progenitor of SN 2023ixf from hydrodynamical modelling
Context: Supernova (SN) 2023ixf is among the most nearby Type II SNe in the
last decades. As such, there is a wealth of observational data of both the
event itself and of the associated object identified in pre-explosion images.
This allows to perform a variety of studies that aim at determining the SN
properties and the nature of the putative progenitor star. Modelling of the
light curve is a powerful method to derive physical properties independently of
direct progenitor analyses. Aims: To investigate the physical nature of SN
2023ixf based on hydrodynamical modelling of its bolometric light curve and
expansion velocities during the complete photospheric phase. Methods: A grid of
one dimensional explosions was calculated for evolved stars of different
masses. We derived properties of SN 2023ixf and its progenitor by comparing our
models with the observations. Results: The observations are well reproduced by
the explosion of a star with zero age main sequence mass of f , an explosion energy of erg, and a nickel
production of 0.05M . This indicates that SN 2023ixf was a normal event. Our
modelling suggests a limit of and therefore
favours the low mass range among the results from pre-explosion observations.Comment: Accepted - A&A Lette
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