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Abstract In all three domains of life, genes with related functions can be organized into specific genomic regions known as gene clusters. In eukaryotes, histone, piRNA (Piwi-interacting RNA), and rDNA (ribosomal DNA) clusters are among the most notable clusters which play fundamental roles in chromatin formation, genome integrity, and translation, respectively. These clusters have long been thought to be regulated by distinct transcriptional mechanisms. In this study, using Caenorhabditis elegans as a model system we identify ATTF-6, a member of the AT-hook family, as a key factor for the expression of histone, piRNA, and 5S rDNA-SL1 (spliced leader 1) clusters. ATTF-6 is essential for C. elegans viability. It forms distinct nuclear foci at both piRNA and 5S rDNA-SL1 clusters. Loss of ATTF-6 leads to a depletion of histone mRNAs, SL1 transcripts, and piRNAs. Additionally, we demonstrate that ATTF-6 is required for the recruitment of USTC (Upstream Sequence Transcription Complex) to piRNA clusters, which is necessary for piRNA production. Collectively, our findings reveal a unifying role for an AT-hook transcription factor in promoting the expression of fundamental gene clusters. 

The coronavirus disease 2019 (COVID-19) has caused devastating public health, economic, political, and societal crises. We performed a comparison study of COVID-19 outbreaks in states with Republican governors versus states with Democratic governors in the United States between April 2020 and February 2021. This research study shows that 1) states with Democratic governors had tested more people for COVID-19 and have higher testing rates than those with Republican governors; 2) states with Democratic governors had more confirmed cases for COVID-19 from April 12 until the end of July 2020, as well as from early December 2020 to February 22 2021, and had higher test positivity rates from April 12 until late June 2020, and the states with Republican governors had more confirmed cases from August to early December 2020 and had higher test positivity rates since late June 2020; 3) states with Democratic governors had more deaths for COVID-19 and higher mortality rates than those with Republican governors; 4) more people recovered in states with Democratic governors until early July 2020, while the recovery rate of states with Republican governors is similar to that of states with Democratic governors in May 2020 and higher than that of states with Democratic governors in April 2020 and between June 2020 to February 22 2021. We conclude that our data suggest that states with Republican governors controlled COVID-19 better as they had lower mortality rates and similar or higher recovery rates. States with Democratic governors first had higher test positivity rates until late June 2020 but had lower test positivity rates after July 2020. As of February 2021, the pandemic was still spreading as the daily numbers of confirmed cases and deaths were still high, although the test positivity and mortality rates started to stabilize in spring 2021. This study provides a direct description for the status and performance of handling COVID-19 in the states with Republican governors versus states with Democratic governors, and provides insights for future research, policy making, resource distribution, and administration. 

Eukaryotic genomes are folded into loops. It is thought that these are formed by cohesin complexes via extrusion, either until loop expansion is arrested by CTCF or until cohesin is removed from DNA by WAPL. Although WAPL limits cohesin’s chromatin residence time to minutes, it has been reported that some loops exist for hours. How these loops can persist is unknown. We show that during G1-phase, mammalian cells contain acetylated cohesinSTAG1 which binds chromatin for hours, whereas cohesinSTAG2 binds chromatin for minutes. Our results indicate that CTCF and the acetyltransferase ESCO1 protect a subset of cohesinSTAG1 complexes from WAPL, thereby enable formation of long and presumably long-lived loops, and that ESCO1, like CTCF, contributes to boundary formation in chromatin looping. Our data are consistent with a model of nested loop extrusion, in which acetylated cohesinSTAG1 forms stable loops between CTCF sites, demarcating the boundaries of more transient cohesinSTAG2 extrusion activity.