The BioCascade-VIVAS system for collection and delivery of virus-laden size-fractionated airborne particles

The size of virus-laden particles determines whether aerosol or droplet transmission is dominant in the airborne transmission of pathogens. Determining dominant transmission pathways is critical to implementing effective exposure risk mitigation strategies. The aerobiology discipline greatly needs an air sampling system that can collect virus-laden airborne particles, separate them by particle diameter, and deliver them directly onto host cells without inactivating virus or killing cells. We report the use of a testing system that combines a BioAerosol Nebulizing Generator (BANG) to aerosolize Human coronavirus (HCoV)-OC43 (OC43) and an integrated air sampling system comprised of a BioCascade impactor (BC) and Viable Virus Aerosol Sampler (VIVAS), together referred to as BC-VIVAS, to deliver the aerosolized virus directly onto Vero E6 cells. Particles were collected into four stages according to their aerodynamic diameter (Stage 1: >9.43 μm, Stage 2: 3.81–9.43 μm, Stage 3: 1.41–3.81 μm and Stage 4: <1.41 μm). OC43 was detected by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) analyses of samples from all BC-VIVAS stages. The calculated OC43 genome equivalent counts per cm3 of air ranged from 0.34 ± 0.09 to 70.28 ± 12.56, with the highest concentrations in stage 3 (1.41–3.81 μm) and stage 4 (<1.41 μm). Virus-induced cytopathic effects appeared only in cells exposed to particles collected in stages 3 and 4, demonstrating the presence of viable OC43 in particles <3.81 μm. This study demonstrates the dual utility of the BC-VIVAS as particle size-fractionating air sampler and a direct exposure system for aerosolized viruses. Such utility may help minimize conventional post-collection sample processing time required to assess the viability of airborne viruses and increase the understanding about transmission pathways for airborne pathogens. •Viable OC43 was present in particles <3.81 μm.•Direct delivery of viable OC43 to host cells through the BC-VIVAS was demonstrated.•Dual utility of BC-VIVAS as an air sampler and exposure system was proven

Comprehensive phylogeny of Pieridae butterflies reveals strong correlation between diversification and temperature

Summary: Temperature is thought to be a key factor influencing global species richness patterns. We investigate the link between temperature and diversification in the butterfly family Pieridae by combining next generation DNA sequences and published molecular data with fine-grained distribution data. We sampled nearly 600 pierid butterfly species to infer the most comprehensive molecular phylogeny of the family and curated a distribution dataset of more than 800,000 occurrences. We found strong evidence that species in environments with more stable daily temperatures or cooler maximum temperatures in the warm seasons have higher speciation rates. Furthermore, speciation and extinction rates decreased in tandem with global temperatures through geological time, resulting in a constant net diversification

A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

International audienceButterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin ~100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants

Fig. 1 in A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

Fig. 1 | Evolutionaryrelationshipsanddiversificationpatternsofbutterflies. Time-calibratedtreeof 2,244 butterflyspeciesbasedon 391 loci and 150 amino acidpartitions.Branchesshowdistinctchangesindiversification (circles) asestimatedbyclade-specificmodels.Lettersatnodesrefertocladeswith significantrateshifts (seesection 6 of Supplementary Results).Colouredlines intheouterringbesidetipsindicateassociationwithoneof the 13 hostmodules (seesection 17 of Extended Online Methods).Blacklinesinthehostassociation ringindicatespecieswithoutdata,andasterisksdenotenon-monophyletic subfamilies.Supplementary Fig. 1 showsthistreewithvisiblespeciesnamesand agesforallnodes.Published as part of &lt;i&gt;Kawahara, Akito Y., Storer, Caroline, Carvalho, Ana Paula S., Plotkin, David M., Condamine, Fabien L., Braga, Mariana P., Ellis, Emily A., St Laurent, Ryan A., Li, Xuankun, Barve, Vijay, Cai, Liming, Earl, Chandra, Frandsen, Paul B., Owens, Hannah L., Valencia-Montoya, Wendy A., Aduse-Poku, Kwaku, Toussaint, Emmanuel F. A., Dexter, Kelly M., Doleck, Tenzing, Markee, Amanda, Messcher, Rebeccah, Nguyen, Y-Lan, Badon, Jade Aster T., Benítez, Hugo A., Braby, Michael F., Buenavente, Perry A. C., Chan, Wei-Ping, Collins, Steve C., Rabideau Childers, Richard A., Dankowicz, Even, Eastwood, Rod, Fric, Zdenek F., Gott, Riley J., Hall, Jason P. W., Hallwachs, Winnie, Hardy, Nate B., Sipe, Rachel L. Hawkins, Heath, Alan, Hinolan, Jomar D., Homziak, Nicholas T., Hsu, Yu-Feng, Inayoshi, Yutaka, Itliong, Micael G. A., Janzen, Daniel H., Kitching, Ian J., Kunte, Krushnamegh, Lamas, Gerardo, Landis, Michael J., Larsen, Elise A., Larsen, Torben B., Leong, Jing V., Lukhtanov, Vladimir, Maier, Crystal A., Martinez, Jose I., Martins, Dino J., Maruyama, Kiyoshi, Maunsell, Sarah C., Mega, Nicolás Oliveira, Monastyrskii, Alexander, Morais, Ana B. B., Müller, Chris J., Naive, Mark Arcebal K., Nielsen, Gregory, Padrón, Pablo Sebastián, Peggie, Djunijanti, Romanowski, Helena Piccoli, Sáfián, Szabolcs, Saito, Motoki, Schröder, Stefan, Shirey, Vaughn, Soltis, Doug, Soltis, Pamela, Sourakov, Andrei, Talavera, Gerard, Vila, Roger, Vlasanek, Petr, Wang, Houshuai, Warren, Andrew D., Willmott, Keith R., Yago, Masaya, Jetz, Walter, Jarzyna, Marta A., Breinholt, Jesse W., Espeland, Marianne, Ries, Leslie, Guralnick, Robert P., Pierce, Naomi E. &amp; Lohman, David J., 2023, A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins, pp. 903-913 in Nature Ecology &amp; Evolution 7 (6)&lt;/i&gt; on page 904, DOI: 10.1038/s41559-023-02041-9, &lt;a href="http://zenodo.org/record/7963518"&gt;http://zenodo.org/record/7963518&lt;/a&gt