50 research outputs found

    Ongoing Rapid Evolution of a Post-Y Region Revealed by Chromosome-Scale Genome Assembly of a Hexaploid Monoecious Persimmon (Diospyros kaki)

    Get PDF
    Plants have evolved sex chromosomes independently in many lineages, and loss of separate sexes can also occur. In this study, we assembled a monoecious recently hexaploidized persimmon (Diospyros kaki), in which the Y chromosome has lost the maleness-determining function. Comparative genomic analysis of D. kaki and its dioecious relatives uncovered the evolutionary process by which the nonfunctional Y chromosome (or Y-monoecy) was derived, which involved silencing of the sex-determining gene, OGI, approximately 2 million years ago. Analyses of the entire X and Y-monoecy chromosomes suggested that D. kaki's nonfunctional male-specific region of the Y chromosome (MSY), which we call a post-MSY, has conserved some characteristics of the original functional MSY. Specifically, comparing the functional MSY in Diospyros lotus and the nonfunctional "post-MSY" in D. kaki indicated that both have been rapidly rearranged, mainly via ongoing transposable element bursts, resembling structural changes often detected in Y-linked regions, some of which can enlarge the nonrecombining regions. The recent evolution of the post-MSY (and possibly also MSYs in dioecious Diospyros species) therefore probably reflects these regions' ancestral location in a pericentromeric region, rather than the presence of male-determining genes and/or genes controlling sexually dimorphic traits

    Molecular Mechanism Underlying Derepressed Male Production in Hexaploid Persimmon

    Get PDF
    Sex expression in plants is often flexible and contributes to the maintenance of genetic diversity within a species. In diploid persimmons (the genus Diospyros), the sexuality is controlled by the Y chromosome-encoded small-RNA gene, OGI, and its autosomal counterpart, MeGI. Hexaploid Oriental persimmon (Diospyros kaki) evolved more flexible sex expression, where genetically male individuals carrying OGI can produce both male and female flowers (monoecy). This is due to (semi-)inactivation of OGI by the Kali-SINE retrotransposon insertion on the promoter region and the resultant DNA methylations. Instead, flower sex determination in Oriental persimmon is also dependent on DNA methylation states of MeGI. Here, we focused on a cultivar, Kumemaru, which shows stable male flower production. Our results demonstrated that cv. Kumemaru carries OGI with Kali-SINE, which was highly methylated as well as in other monoecious cultivars; nevertheless, OGI gene could have a basal expression level. Transcriptomic analysis between cv. Kumemaru and 14 cultivars that predominantly produce female flowers showed differentially expressed genes (DEGs) specific to cv. Kumemaru, which is mainly involved in stress responses. Co-expression gene networks focusing on the DEGs also suggested the involvement of stress signals, mainly via gibberellin (GA), salicylic acid (SA), and especially jasmonic acid (JA) signal pathways. We also identified potential regulators of this co-expression module, represented by the TCP4 transcription factor. Furthermore, we attempted to identify cv. Kumemaru-specific transcript polymorphisms potentially contributing to derepressed OGI expression by cataloging subsequences (k-mers) in the transcriptomic reads from cv. Kumemaru and the other 14 female cultivars. Overall, although the direct genetic factor to activate OGI remains to be solved, our results implied the involvement of stress signals in the release of silenced OGI and the resultant continuous male production

    Jumping to conclusion bias in adolescents with ASD

    Get PDF
    Background and Purpose: Jumping to conclusion (JTC)—a cognitive bias in thinking processes—leads to drawing conclusions based on little information, and could be related to psychosis and paranoia. While it has recently been pointed out that it could accompany the autism spectrum disorder (ASD), no interventions targeting this bias in adolescents with ASD have been reported. Therefore, this exploratory study investigated the effects of a group social cognition program on JTC bias in adolescents with ASD. Patients and Methods : Group rehabilitation using social cognition and interaction training (SCIT) was conducted for 12- to 18-year-old adolescents with ASD. An SCIT program comprehensively targets social cognitive functions, including interventions for JTC bias, and examines changes before and after the SCIT intervention, social cognitive functioning tasks, and subjective quality of life (QOL). Results : Thirteen adolescents with ASD participated in this program ; 10 (76.9%) stayed through it. The proportion of participants with JTC bias decreased significantly before and after SCIT (before : 7 / 10 ; after : 1 / 10 ; p = 0.041), and subjective QOL increased significantly (p = 0.014). Conclusion : The results show that a group social cognition program with a JTC bias approach improves the JTC bias and increases subjective QOL in adolescents with ASD

    An Up-to-Date Anti-Cancer Treatment Strategy Focusing on HIF-1α Suppression: Its Application for Refractory Ovarian Cancer

    Get PDF
    Hypoxia inducible factor-1α (HIF-1α) predominantly determines the transcriptional activity of HIF-1, which induces the certain genetic expressions to participate in the proliferation and progression of the tumor. It is supposed that HIF-1α is also an extremely important factor in cancer treatment. Based on the results of our recent analyses using ovarian tumors, which indicated the close association of HIF-1α expression with the acquisition of malignancy and the characterization of histology, we further investigated the possibility of a new strategy of cancer therapy that targeted HIF-1α inhibition in the ovarian carcinoma. The cell line HUOCA-II, which originates from the refractory ovarian clear cell adenocarcinoma, was treated with rapamycin. The inhibitory effect of HIF-1α was analyzed by immunohistochemistry and western blotting. It was demonstrated that inhibition of HIF-1α and vascular endothelial growth factor (VEGF) expressions would lead to the down-regulation of tumor cell proliferation. Interestingly, there was little or no change in GLUT-1 expression by rapamycin administration. Thus, the inhibition of GLUT-1 may also be a key for the new strategy of cancer therapy as well as HIF-1α and VEGF

    医療的ケアを必要とする在宅療養児のきょうだいへの支援

    Get PDF
    本研究は、医療的ケアを必要とする在宅療養児のきょうだいが抱えた思いや悩み、在宅療養児の疾患認識、きょうだい支援の現状やニーズを明らかにし、それらの結果から今後の支援のあり方を考察することを目的とした。対象は医療的ケアが必要な在宅療養児をきょうだいにもつ青年2名であり、インタビューガイドに基づいて半構成的面接法を実施した。その結果、8つのカテゴリーが抽出され、きょうだいが在宅療養児を通して良い影響を大きく受けていた一方で、課題として在宅療養児の疾患の共有時期・理解度、必然的に医療的ケアに関わらざるを得ない環境、ライフ・イベント時に直面する問題、将来きょうだいが在宅療養児を支える際の問題などが挙がった。きょうだいへの支援においては親の受容状況なども大切な視点であり、保健福祉医療の各側面からのきょうだい支援が必要であることが示唆された
    corecore