RESUMEN
In recent years, head injuries in sports have garnered attention, and in particular, international discussions have been held on the prevention of and response to sports-related concussions (SRCs). The purpose of this study is to investigate past SRCs experienced by university students in Japan, clarify the state and mechanism of such injuries in each sport, and consider the creation of an environment for future SRC prevention and responses. A questionnaire survey on past SRC experience was conducted among 1731 students who belonged to Fukuoka University in Japan and took "sports medicine" classes in 2020. Responses from 1140 students (collection rate: 65.9%) were obtained. According to this survey, it was revealed that 39 students (3.7%) had experienced SRC. The male-female ratio of those who had experienced SRC was 31 males (79.5%) and 8 females (20.5%). Two males had experienced SRC twice. In this study, SRCs were recognized in a variety of sports, not just in a few contact sports. It is necessary to further disseminate education on head injury prevention and SRCs among both athletes and coaches, because SRCs have been frequently recognized in various sports.
RESUMEN
Vernalization is the promotion of flowering after prolonged exposure to cold. In Arabidopsis thaliana, vernalization induces epigenetic silencing of the floral repressor gene FLOWERING LOCUS C (FLC). Among the repressive epigenetic marks, the trimethylation of lysine 27 on histone H3 proteins (H3K27me3) is a critical contributor to the epigenetic silencing of FLC. The deposition of H3K27me3 is mediated by Polycomb Repressive Complex 2 (PRC2). Conversely, the elimination of H3K27me3 is mediated by histone demethylases, Jumonji-C domain-containing protein JMJ30 and its homolog JMJ32. However, the role of JMJ30 and JMJ32 in vernalization is largely unknown. In this study, we found that cold treatment dramatically reduced the expression levels of JMJ30 and did not reduce those of JMJ32. Next, by using the genetic approach, we found that the flowering of jmj30 jmj32 was accelerated under moderate vernalized conditions. Under moderate vernalized conditions, the silencing of FLC occurred more quickly in jmj30 jmj32 than in the wild type. These results suggested that the histone demethylases JMJ30 and JMJ32 brake vernalization through the activation of FLC. Our study suggested that PRC2 and Jumonji histone demethylases act in an opposing manner to regulate flowering time via epigenetic modifications.
