Multiple Copies of flhDC in Paraburkholderia unamae Regulate Flagellar Gene Expression, Motility, and Biofilm Formation.

FlhDC is a heterohexameric complex that acts as a master regulator of flagellar biosynthesis genes in numerous bacteria. Previous studies have identified a single flhDC operon encoding this complex. However, we found that two flhDC loci are present throughout Paraburkholderia, and two additional flhC copies are also present in Paraburkholderia unamae. Systematic deletion analysis in P. unamae of the different flhDC copies showed that one of the operons, flhDC1, plays the predominant role, with deletion of its genes resulting in a severe inhibition of motility and biofilm formation. Expression analysis using promoter-lacZ fusions and real-time quantitative PCR support the primary role of flhDC1 in flagellar gene regulation, with flhDC2 a secondary contributor. Phylogenetic analysis shows the presence of the flhDC1 and flhDC2 operons throughout Paraburkholderia. In contrast, Burkholderia and other bacteria only carry the copy syntenous with flhDC2. The variations in impact each copy of flhDC has on downstream processes indicate that regulation of FlhDC in P. unamae, and likely other Paraburkholderia species, is regulated at least in part by the presence of multiple copies of these genes. IMPORTANCE Motility is important in the colonization of plant roots by beneficial and pathogenic bacteria, with flagella playing essential roles in host cell adhesion, entrance, and biofilm formation. Flagellar biosynthesis is energetically expensive. Its complex regulation by the FlhDC master regulator is well studied in peritrichous flagella expressing enterics. We report the unique presence throughout Paraburkholderia of multiple copies of flhDC. In P. unamae, the flhDC1 copy showed higher expression and a greater effect on swim motility, flagellar development, and regulation of downstream genes, than the flhDC2 copy that is syntenous to flhDC in Escherichia coli and pathogenic Burkholderia spp. The flhDC genes have evolved differently in these plant-growth-promoting bacteria, giving an additional layer of complexity in gene regulation by FlhDC.

Content analysis of tobacco imagery in popular music Videos, 2018-2021.

Exposure to tobacco imagery in movies and television has been identified as a key factor to youth smoking initiation (Davis, 2008; Bennett et al., 2020). This study aims to investigate the prevalence of tobacco imagery in popular music videos from 2018 to 2021. The weekly top 10 songs of 2018-2021 were identified using Billboard Charts categories (Hot 100, Hot R&B/Hip-Hop, Country, Rock & Alternative, Dance/Electronic, Pop Airplay). Content analyses of the top music videos using the Thumbs up Thumbs Down methodology were conducted to identify tobacco depictions on screen. The sample consisted of 1,008 music videos across four years; 196 of which contained tobacco imagery (19.4%). Between 2018 and 2021, the proportion of videos with tobacco imagery ranged between 12.8% and 23.0% of the total year sample. Tobacco incidences almost doubled from 280 occurrences in 2018 to 522 occurrences in 2020, but decreased by over half to 290 occurrences in 2021. Tobacco incidences varied by year and genre, with Hot 100 being the top offending genre in 2018 with 40.0% of videos containing tobacco imagery while Hot R&B/Hip-Hop was the top offending genre from 2019 to 2021 (52.7%, 52.5%, and 23.9% respectively). Cigarettes were most pervasive in 2019 (70.1% of total tobacco incidences), 2020 (45.6%), and 2021 (64.1%) music videos. Pipes were the most pervasive product in 2018 music videos (39.6%). Given the reach and frequency of exposure to music videos among young people, reducing tobacco imagery in popular music videos may prevent tobacco use among young people.