Genetic mechanism for soil-surface roots originating from a New Plant Type rice (Oryza sativa L.)

A new method of using seedling trays to evaluate root angle distribution in rice (Oryza sativa. L) was developed. By using this method, the root angle distributions of 97 accessions were characterized into two cluster groups ; A and B. The numbers of accessions in group A were limited, and these were categorized as shallow rooting types including soil-surface root. Group B included from shallow to deep rooting types, including both Indica and Japonica Group cultivars, lowland and upland cultivars, and landraces and improved types. An introgression line YTH16 harboring chromosome segments from a New Plant Type cultivar IR65600-87-2-2-3 with genetic background of an Indica Group rice IR 64, was included in Group A. To clarify the genetic mechanism for soil-surface rooting, quantitative trait loci (QTL) analysis was performed using hybrid populations derived from a cross between IR 64 and YTH16. A total of 8 QTLs were detected in the 3 introgressed segments on chromosomes (chr.) 2, 5 and 7. Seven chromosome segment lines (CSLs) combining these 3 QTL regions were selected from the progenies. The 2 CSLs harboring a single region (excluding the CSL with a region on chr. 5) showed high soil-surface root scores and low root vertical angles (RVA) in comparison with IR 64. Four CSLs harboring 2 or 3 regions showed high scores and low RVAs in comparison with YTH16 and the CSLs harboring a single QTL region. These results indicated that the soil-surface and shallow rooting of YTH16 was controlled by the 2 major QTLs’ regions on chrs. 2 and 7, and that chr. 5 particularly played a role for supporting the effect with them

Genetic factors for yield related traits in lowland New Rice for Africa (NERICA)

Genetic factors of yield related traits in lowland New Rice for Africa variety (NERICA) using different nitrogen condition and QTL to increase rice yield in lowland NERICAs were clarified. Indica Group rice variety (Oryza sativa L.) IR64 increased panicle number, culm weight and panicle weight, according to nitrogen concentration. The tendency is especially remarkable under low nitrogen concentration. NERICA‒L‒19, which is derived from a cross between IR64 and TOG5681 (Oryza glaberrima S.), showed similar values for panicle weight and culm weight, and it showed higher plant height, panicle weight and culm weight and lower harvest index than those of IR64 under all the concentrations. QTL analysis for the agronomic traits were performed using hybrid population derived from a cross between IR64 and NERICA‒L‒19. A total of 22 QTLs were detected on chromosomes (chrs.) 1 (3 QTLs), 2 (2), 4 (2), 5 (5), 6 (1), 7 (1), 8 (6) and 10 (2). Among them, 4 regions at 34.1‒36.6Mbp of chr. 1, at 23.8‒27.8Mbp of chr. 5 and at 4.8Mbp and 20.3‒28.4Mbp of chr. 8 showed several QTLs’ peaks overlapped. The regions of chr. 5 and 4.8Mbp of chr. 8 increased panicle weight by IR64 allele. Those of chr. 1 and 20.3-28.4Mbp of chr. 8 increased plant height and harvest index, respectively, by NERICA‒L‒19 allele. These results indicated that the larger panicle type of lowland NERICA is suitable under low nitrogen condition. Also, the plant type was controlled by the combination of 4 QTLs’ regions on chr. 1 and short arm of chr. 8 originated from O. glaberrima, and those of chr. 5 and long arm of chr. 8 from O. sativa Indica Group

Changes in Pediatric Patient Trends in Eating and Swallowing Disorders: A Comparison between the First and Fifth Year after Establishment of the Special Needs Dental Center

A Special Needs Dental Center （hereafter referred to as the Center） was established at Showa University Dental Hospital in April 2012 to treat patients who need special care. In cooperation with the Division of Dentistry for Persons with Disabilities, the Division of Hygiene and Oral Health is mainly engaged in the treatment of patients with eating and swallowing disorders. It has been five years since the establishment of the Center. The present study was aimed to establish an effective medical support method through a comparative study of changes in patient trends. A total of 65 patients who visited the Center from April 2017 to March 2018 were examined and their statistics were compared with those of 60 previously reported patients who initially visited the Center for medical examination in 2012. In 2012, many visits occurred during the nursing period; however, in 2017, the number of patients who visited after the weaning period increased. Other noted trends were increased diversity in primary disease, more patient referrals, fewer patients with severe swallowing dysfunction, and more patients with oral dysfunction. The necessity of eating and swallowing practice is thought to increase when lifestyle and oral environment change. The treatment of eating and swallowing disorders is important in the dental profession. Due to the introduction of insurance coverage in Japan in 2018 for developmental insufficiency of oral function, more pediatric patients with eating and swallowing disorders will likely be treated in the future

Clinical Statistics for Dysphagia Patients ≦ 18 Years of Age in the Center of Special Needs Dentistry, April 2012-March 2013

In April 2012, the Center of Special Needs Dentistry (SND) was established at Showa University Dental Hospital to provide function training for children with eating and swallowing disorders. A statistical clinical assessment was performed on new patients ≤18 years of age who visited the Center over a 1-year period (April 2012–March 2013) to assess the conditions present at the initial visit. In all, 60 patients (29 boys, 31 girls, mean (± SD) age 4.2±4.1 years, range 0-18 years of age) were included in the study. Most patients were <1 year of age (32%) and most came from one of four cities in the Johnan area (Shinagawa City, Meguro City, Ota City and Setagaya City). The most common primary diseases at the initial visit were cerebral palsy and cleft lip and palate. The third largest patient group was of healthy children with oral function problem. Over 60% of patients attended the Center of SND because of an eating-related complaint. More than 50% of patients were obtaining nutrients via oral intake; the remaining patients were obtaining nutrients via non-oral or a combination of oral and non-oral intake. Because of the young age of the patients and the fact that most were from neighboring areas, it can be inferred that effective community health care is being provided. It is necessary for the Center of SND to continue to provide professional treatment for dysphagia and to contribute to community medicine

Promises of stem cell therapy for retinal degenerative diseases

With the development of stem cell technology, stem cell-based therapy for retinal degeneration has been proposed to restore the visual function. Many animal studies and some clinical trials have shown encouraging results of stem cell-based therapy in retinal degenerative diseases. While stem cell-based therapy is a promising strategy to replace damaged retinal cells and ultimately cure retinal degeneration, there are several important challenges which need to be overcome before stem cell technology can be applied widely in clinical settings. In this review, different types of donor cell origins used in retinal treatments, potential target cell types for therapy, methods of stem cell delivery to the eye, assessments of potential risks in stem cell therapy, as well as future developments of retinal stem cells therapy, will be discussed

Regulatory role of Pax6 on cell division cycle associated 7 and cortical progenitor cell proliferation

Forebrain development is controlled by a set of transcription factors which are expressed in dynamic spatiotemporal patterns in the embryonic forebrain and are known to regulate complex gene networks. Pax6 is a transcription factor that regulates corticogenesis and mutations affecting Pax6 protein levels cause neurodevelopmental defects in the eyes and forebrain in both humans and mice. In previous studies, it was shown that the graded expression pattern of Pax6 protein, which is high rostro-laterally to low caudo-medially in the cerebral cortex, is critical for its control of cell cycle progression and proliferation of cortical progenitors. However the underlying mechanisms are still unclear. Based on a microarray analysis carried out in our laboratory, a number of cell cycle-related candidate genes that may be affected by Pax6 have been identified. One such gene, Cell division cycle associated 7 (Cdca7) is expressed in a counter-gradient against that of Pax6. In my current study, I found that Cdca7 mRNA expression in the telencephalon is upregulated in Pax6 null (Small eye) mutants and downregulated in mice that overexpress PAX6 (PAX77) across developing time points from E12.5 to E15.5. There are several potential Pax6 binding motifs located in the genomic locus upstream of Cdca7. However, by chromatin immunoprecipitation, it is showed that none of the predicted binding sites are physically bound by Pax6. Promoter luciferase assays using fragments combining five suspected binding motifs show that Pax6 is functionally critical. Cdca7 is also identified as a Myc and E2F1 direct target and is upregulated in some tumours but its biological role is not fully understood. Current work using in utero electroporation to overexpress Cdca7 around the lateral telencephalon, where Cdca7 expression levels are normally low, tested the effects on the proliferation and differentiation of cortical progenitor cells in this region. In E12.5 mice embryos, overexpression of Cdca7 protein causes fewer intermediate progenitor cells and post-mitotic neurons to be produced but these effects were not found in E14.5 embryos. This result implies that Cdca7 may affect cell fate decision during cortical development

Genetic mechanism for soil-surface roots originating from a New Plant Type rice (Oryza sativa L.)

A new method of using seedling trays to evaluate root angle distribution in rice (Oryza sativa. L) was developed. By using this method, the root angle distributions of 97 accessions were characterized into two cluster groups ; A and B. The numbers of accessions in group A were limited, and these were categorized as shallow rooting types including soil-surface root. Group B included from shallow to deep rooting types, including both Indica and Japonica Group cultivars, lowland and upland cultivars, and landraces and improved types. An introgression line YTH16 harboring chromosome segments from a New Plant Type cultivar IR65600-87-2-2-3 with genetic background of an Indica Group rice IR 64, was included in Group A. To clarify the genetic mechanism for soil-surface rooting, quantitative trait loci (QTL) analysis was performed using hybrid populations derived from a cross between IR 64 and YTH16. A total of 8 QTLs were detected in the 3 introgressed segments on chromosomes (chr.) 2, 5 and 7. Seven chromosome segment lines (CSLs) combining these 3 QTL regions were selected from the progenies. The 2 CSLs harboring a single region (excluding the CSL with a region on chr. 5) showed high soil-surface root scores and low root vertical angles (RVA) in comparison with IR 64. Four CSLs harboring 2 or 3 regions showed high scores and low RVAs in comparison with YTH16 and the CSLs harboring a single QTL region. These results indicated that the soil-surface and shallow rooting of YTH16 was controlled by the 2 major QTLs’ regions on chrs. 2 and 7, and that chr. 5 particularly played a role for supporting the effect with them