We have used two different live-cell fluorescent protein markers to monitor the formation and localization of double-strand breaks (DSBs) in budding yeast. Using GFP derivatives of the Rad51 recombination protein or the Ddc2 checkpoint protein, we find that cells with three site-specific DSBs, on different chromosomes, usually display 2 or 3 foci that may coalesce and dissociate. This motion is independent of Rad52 and microtubules. Rad51-GFP, by itself, is unable to repair DSBs by homologous recombination in mitotic cells, but is able to form foci and allow repair when heterozygous with a wild type Rad51 protein. The kinetics of formation and disappearance of a Rad51-GFP focus parallels the completion of site-specific DSB repair. However, Rad51-GFP is proficient during meiosis when homozygous, similar to rad51 “site II” mutants that can bind single-stranded DNA but not complete strand exchange. Rad52-RFP and Rad51-GFP co-localize to the same DSB, but a significant minority of foci have Rad51-GFP without visible Rad52-RFP. We conclude that co-localization of foci in cells with 3 DSBs does not represent formation of a homologous recombination “repair center,” as the same distribution of Ddc2-GFP foci was found in the absence of the Rad52 protein.

Background With the approval of three treatments for spinal muscular atrophy (SMA) and several promising therapies on the horizon, the SMA adolescent and young adult populations are expected to evolve in the coming years. It is imperative to understand this cohort as it exists today to provide optimal care and resources, as well as to assess possible treatment effects over time. In 2018, Cure SMA launched two initiatives geared towards understanding adolescents and young adults with SMA, ages 12–25. First, Cure SMA launched a Quality of Life (QoL) survey to capture quantitative and qualitative information on this specific age demographic. Concurrently, Cure SMA invited SMA-affected individuals, ages 12–25, to create a three-minute video on their everyday experiences living with SMA. An inductive thematic analysis of the free-text survey questions along with the video contest findings are reported here. Results Eighty-five individuals—6 type Is, 58 type IIs, and 21 type IIIs—completed the Quality of Life free-response, while six individuals participated in the SMA awareness video contest. In both settings, individuals detailed a variety of challenges, including but not limited to forming or maintaining close relationships, experiencing feelings of isolation, challenges with accessibility, independence, and dealing with the stigma of being perceived as mentally disabled. Individuals also discussed their successes, including but not limited to higher education enrollment and attendance, development of quality friendships, and perseverance through obstacles. Additionally, notably in the survey, 39% of respondents requested the creation of an SMA peer support group in efforts to connect with each other as well as collectively navigate the aforementioned challenges they face. Conclusion Together, these findings provide a rare glimpse into the unique mindsets, challenges and motivations of SMA adolescents and young adults, via patient-reported measures instead of caregiver proxy. The adolescent and young adult age demographics assessed represent a critical transition period in life and in SMA care. No one understands the needs of an adolescent or young adult with SMA better than the individuals themselves, and it is critical to encapsulate their insights to affect change.

We have used two different live-cell fluorescent protein markers to monitor the formation and localization of double-strand breaks (DSBs) in budding yeast. Using GFP derivatives of the Rad51 recombination protein or the Ddc2 checkpoint protein, we find that cells with three site-specific DSBs, on different chromosomes, usually display 2 or 3 foci that coalesce and dissociate. Rad51-GFP, by itself, is unable to repair DSBs by homologous recombination in mitotic cells, but is able to form foci and allow repair when heterozygous with a wild type Rad51 protein. The kinetics of disappearance of Rad51-GFP foci parallels the completion of DSB repair. However, in meiosis, Rad51-GFP is proficient when homozygous. Using Ddc2-GFP, we conclude that co-localization of foci following 3 DSBs does not represent formation of a homologous recombination "repair center," as the same distribution of Ddc2-GFP foci was found in the presence or absence of the Rad52 protein. The maintenance of separate DSB foci and much of their dynamics depend on functional microtubules, as addition of nocodazole resulted in a greater population of cells displaying a single focus.Author SummaryDouble strand breaks (DSBs) pose the greatest threat to the fidelity of an organism’s genome. While much work has been done on the mechanisms of DSB repair, the arrangement and interaction of multiple DSBs within a single cell remain unclear. Using two live-cell fluorescent DSB markers, we show that cells with 3 site-specific DSBs usually form 2 or 3 foci what can coalesce into fewer foci but also dissociate. The aggregation of DSBs into a single focus does not depend on the Rad52 recombination protein, suggesting that there is no “repair center” for homologous recombination. DSB foci are highly dynamic and their dynamic nature is dependent on microtubules.

Background: With the approval of two treatments for spinal muscular atrophy (SMA) and several promising therapies on the horizon, the SMA adolescent and young adult populations are expected to evolve in the coming years. It is imperative to understand this cohort as it exists today to provide optimal care and resources, as well as to assess possible treatment effects over time. In 2018, Cure SMA launched two initiatives geared towards understanding adolescents and young adults with SMA, ages 12-25. First, Cure SMA launched a clinical meaningfulness survey to capture information, quantitatively and qualitatively, on the quality-of-life of this population. Concurrently, Cure SMA invited SMA-affected individuals, ages 12-25, to create a three-minute video on their everyday experiences living with SMA. An inductive thematic analysis of the open-ended section in the survey along with the video contest findings are reported here.Results: Eighty-five individuals — 6 type Is, 58 type IIs, and 21 type IIIs — completed the open-ended section of the survey, while six individuals, mostly type II, participated in the SMA awareness video contest. In both settings, individuals detailed a wide variety of challenges, including but not limited to forming or maintaining close relationships, feelings of isolation, challenges with accessibility, independence, and dealing with the stigma of being perceived as mentally disabled. Individuals also discussed their successes, including but not limited to higher education enrollment and attendance, development of quality friendships, and perseverance through obstacles. Additionally, in the survey, an overwhelming number of respondents (39%) requested the creation of an SMA peer support group in efforts to connect with each other as well as collectively navigate the aforementioned challenges they face. Conclusion: Together, these findings provide a rare glimpse into the unique mindsets, challenges and motivations of SMA adolescents and young adults, via patient-reported measures instead of caregiver proxy. The adolescent and young adult age demographics assessed represent a critical transition period in life and in SMA care. No one understands the needs of an adolescent or young adult with SMA better than the individuals themselves, and it is critical to capture their insights in order to affect change.