TRNA genes affect chromosome structure and function via local effects

The genome is packaged and organized in an ordered, nonrandom manner, and specific chromatin segments contact nuclear substructures to mediate this organization. tRNA genes (tDNAs) are binding sites for transcription factors and architectural proteins and are thought to play an important role in the organization of the genome. In this study, we investigate the roles of tDNAs in genomic organization and chromosome function by editing a chromosome so that it lacked any tDNAs. Surprisingly our analyses of this tDNA-less chromosome show that loss of tDNAs does not grossly affect chromatin architecture or chromosome tethering and mobility. However, loss of tDNAs affects local nucleosome positioning and the binding of SMC proteins at these loci. The absence of tDNAs also leads to changes in centromere clustering and a reduction in the frequency of long-range HML-HMR heterochromatin clustering with concomitant effects on gene silencing. We propose that the tDNAs primarily affect local chromatin structure, which results in effects on long-range chromosome architecture

Loneliness, wellbeing, and social activity in scottish older adults resulting from social distancing during the COVID-19 pandemic

This study examined the impact of social distancing during the COVID-19 pandemic on loneliness, wellbeing, and social activity, including social support, in Scottish older adults. A mixed methods online survey was used to examine these factors during social distancing mid-lockdown, July 2020. Participants were asked to state whether loneliness, wellbeing, social activity, and social support had changed since pre-social distancing, and to provide details of strategies used to keep socially active. A total of 1429 adults (84% aged 60+ years) living in Scotland took part. The majority reported that social distancing regulations made them experience more loneliness and less social contact and support. Loneliness during lockdown was higher than reported norms for this age group before the pandemic. A larger social network, more social contact, and better perceived social support seemed to be protective against loneliness and poor wellbeing. Positive coping strategies reported included increasing online social contact with both existing social networks and reconnecting with previous networks, as well as increasing contact with neighbours and people in the community. This underlines the importance of addressing loneliness and social support in older adults but particularly during situations where risk of isolation is high