Advanced age increases frequencies of de novo mitochondrial mutations in macaque oocytes and somatic tissues.

Mutations in mitochondrial DNA (mtDNA) contribute to multiple diseases. However, how new mtDNA mutations arise and accumulate with age remains understudied because of the high error rates of current sequencing technologies. Duplex sequencing reduces error rates by several orders of magnitude via independently tagging and analyzing each of the two template DNA strands. Here, using duplex sequencing, we obtained high-quality mtDNA sequences for somatic tissues (liver and skeletal muscle) and single oocytes of 30 unrelated rhesus macaques, from 1 to 23 y of age. Sequencing single oocytes minimized effects of natural selection on germline mutations. In total, we identified 17,637 tissue-specific de novo mutations. Their frequency increased ∼3.5-fold in liver and ∼2.8-fold in muscle over the ∼20 y assessed. Mutation frequency in oocytes increased ∼2.5-fold until the age of 9 y, but did not increase after that, suggesting that oocytes of older animals maintain the quality of their mtDNA. We found the light-strand origin of replication (OriL) to be a hotspot for mutation accumulation with aging in liver. Indeed, the 33-nucleotide-long OriL harbored 12 variant hotspots, 10 of which likely disrupt its hairpin structure and affect replication efficiency. Moreover, in somatic tissues, protein-coding variants were subject to positive selection (potentially mitigating toxic effects of mitochondrial activity), the strength of which increased with the number of macaques harboring variants. Our work illuminates the origins and accumulation of somatic and germline mtDNA mutations with aging in primates and has implications for delayed reproduction in modern human societies.

'It is a life changing experience': The experiences of living kidney donors who live in rural Australia.

INTRODUCTION: A growing body of research has examined the physical, psychological, social and financial impacts of living kidney donation. However, little is known about the unique experiences or additional burdens faced by living donors from regional or remote locations. OBJECTIVE: To explore the experiences of living kidney donors who live outside metropolitan centres and to determine how support services could be orientated to better meet their unique needs. DESIGN/SETTING/PARTICIPANTS: Seventeen living kidney donors participated in semistructured telephone interviews. Qualitative data were analysed using thematic analysis. FINDINGS: Eight themes were identified: (1) donor's emotional well-being is influenced by the recipient's outcome, (2) varied levels of access to medical support and other important services in rural areas, (3) travel takes a toll on time, finances and well-being, (4) varied level of financial impact, (5) medical, emotional and social challenges, (6) both lay and health professional support is valued, (7) varied levels of knowledge and experiences accessing information and (8) a worthwhile experience overall. CONCLUSION: Despite many challenges, and travel adding to the complexity, rural living kidney donors generally consider it to be a worthwhile experience. The provision of additional emotional, practical and educational support would be welcomed by this group.

HDAC activity is dispensable for repression of cell-cycle genes by DREAM and E2F:RB complexes.

Histone deacetylases (HDACs) play a crucial role in transcriptional regulation and are implicated in various diseases, including cancer. They are involved in histone tail deacetylation and canonically linked to transcriptional repression. Previous studies suggested that HDAC recruitment to cell-cycle gene promoters via the retinoblastoma (RB) protein or the DREAM complex through SIN3B is essential for G1/S and G2/M gene repression during cell-cycle arrest and exit. Here we investigate the interplay among DREAM, RB, SIN3 proteins, and HDACs in the context of cell-cycle gene repression. Knockout of SIN3B does not globally derepress cell-cycle genes in non-proliferating HCT116 and C2C12 cells. Loss of SIN3A/B moderately upregulates several cell-cycle genes in HCT116 cells but does so independently of DREAM/RB. HDAC inhibition does not induce general upregulation of RB/DREAM target genes in arrested transformed or non-transformed cells. Our findings suggest that E2F:RB and DREAM complexes can repress cell-cycle genes without relying on HDAC activity.

HDAC activity is dispensable for repression of cell-cycle genes by DREAM and E2F:RB complexes.

Histone deacetylases (HDACs) are pivotal in transcriptional regulation, and their dysregulation has been associated with various diseases including cancer. One of the critical roles of HDAC-containing complexes is the deacetylation of histone tails, which is canonically linked to transcriptional repression. Previous research has indicated that HDACs are recruited to cell-cycle gene promoters through the RB protein or the DREAM complex via SIN3B and that HDAC activity is essential for repressing G1/S and G2/M cell-cycle genes during cell-cycle arrest and exit. In this study, we sought to explore the interdependence of DREAM, RB, SIN3 proteins, and HDACs in the context of cell-cycle gene repression. We found that genetic knockout of SIN3B did not lead to derepression of cell-cycle genes in non-proliferating HCT116 and C2C12 cells. A combined loss of SIN3A and SIN3B resulted in a moderate upregulation in mRNA expression of several cell-cycle genes in arrested HCT116 cells, however, these effects appeared to be independent of DREAM or RB. Furthermore, HDAC inhibition did not induce a general upregulation of RB and DREAM target gene expression in arrested transformed or non-transformed cells. Our findings provide evidence that E2F:RB and DREAM complexes can repress cell-cycle genes without reliance on HDAC activity.

A qualitative exploration of the physical and psychological wellbeing of family carers of veterans in Australia.

Family carers of veterans have a tendency not to seek support for their own wellbeing concerns. Understanding the barriers and enablers that family carers face in attending to their own wellbeing and in their caring role generally, is key to supporting family carers of veterans. This qualitative study sought to explore family carers' experiences and perceptions of their caring role, using semi-structured interviews. Questions were designed to capture concepts related to the barriers and enablers family carers face in attending to their own wellbeing. Twenty-two family carers participated in interviews. Thematic analysis facilitated the identification of key themes including the impact of the caring role; a perceived lack of recognition or appreciation of the caring role; expressed preferences for support; and consideration of the family unit. Findings suggest a need for accessible and multi-faceted support services for family carers of veterans, that target the drivers of physical and psychological wellbeing.

Caring for carers: Understanding the physical and psychological well-being of carers of veterans in Australia.

Carers of veterans tend to put their own physical and psychological well-being needs behind the needs of the person they are caring for and often do not seek assistance for their own physical and psychological well-being. Combined, these factors lead to increased risk of acute and chronic illness and mental health issues. It is acknowledged that physical activity independently contributes to improved physical and mental health and may be a driver for mental well-being in carers. The aim of this pilot research was to understand how movement behaviour and health behaviours of carers of veterans in Australia relate to carers' physical and psychological well-being. Assessment occurred between February and July 2019 and included objective, validated measures to examine physical and psychological well-being. To assess the association between physical and psychological factors, correlational analyses were performed. Twenty-eight carers participated in the pilot study (96% female, mean age 61.6 years). Exercise capacity varied, and 84% of carers met the recommended 150 min of physical activity per week, with carers spending 8.6% of their time in moderate-to-vigorous physical activity; and 37.9% of the day sedentary. Psychological health outcomes reflect a population with high distress levels and lower than average mental well-being, but with normal resilience scores. Carers with higher levels of resilience had greater exercise capacity, covering further distance in the 6-min walk test, and as resilience increased, number of sedentary bouts decreased. This research demonstrates that there is a relationship between health behaviours and psychological well-being in carers of veterans and serving personnel. Based on the findings of this pilot study, programmes to support family carers should include information about physical activity, reducing sedentary time, and increasing resilience. Interventions designed to improve physical and psychological well-being should be trialled and evaluated for effectiveness.

Combining Farmers' Preferences With Evidence-Based Strategies to Prevent and Lower Farmers' Distress: Co-design and Acceptability Testing of ifarmwell.

BACKGROUND: Farming is physically and psychologically hazardous. Farmers face many barriers to help seeking from traditional physical and mental health services; however, improved internet access now provides promising avenues for offering support. OBJECTIVE: This study aims to co-design with farmers the content and functionality of a website that helps them adopt transferable coping strategies and test its acceptability in the broader farming population. METHODS: Research evidence and expert opinions were synthesized to inform key design principles. A total of 18 farmers detailed what they would like from this type of website. Intervention logic and relevant evidence-based strategies were mapped. Website content was drafted and reviewed by 2 independent mental health professionals. A total of 9 farmers provided detailed qualitative feedback on the face validity of the draft content. Subsequently, 9 farmers provided feedback on the website prototype. Following amendments and internal prototype testing and optimization, prototype usability (ie, completion rate) was examined with 157 registered website users who were (105/157, 66.9%) female, aged 21-73 years; 95.5% (149/156) residing in inner regional to very remote Australia, and 68.2% (107/157) "sheep, cattle and/or grain farmers." Acceptability was examined with a subset of 114 users who rated at least module 1. Interviews with 108 farmers who did not complete all 5 modules helped determine why, and detailed interviews were conducted with 18 purposively sampled users. Updates were then made according to adaptive trial design methodology. RESULTS: This systematic co-design process resulted in a web-based resource based on acceptance and commitment therapy and designed to overcome barriers to engagement with traditional mental health and well-being strategies-ifarmwell. It was considered an accessible and confidential source of practical and relevant farmer-focused self-help strategies. These strategies were delivered via 5 interactive modules that include written, drawn, and audio- and video-based psychoeducation and exercises, as well as farming-related jokes, metaphors, examples, and imagery. Module 1 included distress screening and information on how to speak to general practitioners about mental health-related concerns (including a personalized conversation script). Modules were completed fortnightly. SMS text messages offered personalized support and reminders. Qualitative interviews and star ratings demonstrated high module acceptability (average 4.06/5 rating) and suggested that additional reminders, higher quality audio recordings, and shorter modules would be useful. Approximately 37.1% (52/140) of users who started module 1 completed all modules, with too busy or not got to it yet being the main reason for non-completion, and previous module acceptability not predicting subsequent module completion. CONCLUSIONS: Sequential integration of research evidence, expert knowledge, and farmers' preferences in the co-design process allowed for the development of a self-help intervention that focused on important intervention targets and was acceptable to this difficult-to-engage group. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12617000506392; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372526.

Pronounced somatic bottleneck in mitochondrial DNA of human hair.

Heteroplasmy is the presence of variable mitochondrial DNA (mtDNA) within the same individual. The dynamics of heteroplasmy allele frequency among tissues of the human body is not well understood. Here, we measured allele frequency at heteroplasmic sites in two to eight hairs from each of 11 humans using next-generation sequencing. We observed a high variance in heteroplasmic allele frequency among separate hairs from the same individual-much higher than that for blood and cheek tissues. Our population genetic modelling estimated the somatic bottleneck during embryonic follicle development of separate hairs to be only 11.06 (95% confidence interval 0.6-34.0) mtDNA segregating units. This bottleneck is much more drastic than somatic bottlenecks for blood and cheek tissues (136 and 458 units, respectively), as well as more drastic than, or comparable to, the germline bottleneck (equal to 25-32 or 7-10 units, depending on the study). We demonstrated that hair undergoes additional genetic drift before and after the divergence of mtDNA lineages of individual hair follicles. Additionally, we showed a positive correlation between donor's age and variance in heteroplasmy allele frequency in hair. These findings have important implications for forensics and for our understanding of mtDNA dynamics in the human body. This article is part of the theme issue 'Linking the mitochondrial genotype to phenotype: a complex endeavour'.

Informed consent to breech birth in New Zealand.

The authors note significant room for improvement in facilitating informed consent in the management of breech presentation. New Zealand maternity care providers, including midwives, general practitioners and specialist obstetricians, have legal duties to provide full and unbiased information about risks and benefits of all relevant treatment options. In the case of breech presentation, such options include the interventions of external cephalic version or planned caesarean section, as well as the option to decline intervention and proceed with a planned vaginal breech birth. Information should be presented in a balanced and accessible way and not limited to the provider's personal preferences. Women have legal rights to make an informed choice, to give or refuse consent, to a second opinion and to co-operation among providers. The right of competent persons to refuse medical treatment, including the right to refuse caesarean section, is well established. Clinical policies therefore should include appropriate and non-coercive care for women who choose to birth their breech-presenting baby vaginally, compliance with such policies should be the norm, and consideration should be given to any institutional reforms or educational priorities needed to achieve this.