Fertilization controls tiller numbers via transcriptional regulation of a MAX1-like gene in rice cultivation

Fertilization controls various aspects of cereal growth such as tiller number, leaf size, and panicle size. However, despite such benefits, global chemical fertilizer use must be reduced to achieve sustainable agriculture. Here, based on field transcriptome data from leaf samples collected during rice cultivation, we identify fertilizer responsive genes and focus on Os1900, a gene orthologous to Arabidopsis thaliana MAX1, which is involved in strigolactone biosynthesis. Elaborate genetic and biochemical analyses using CRISPR/Cas9 mutants reveal that Os1900 together with another MAX1-like gene, Os5100, play a critical role in controlling the conversion of carlactone into carlactonoic acid during strigolactone biosynthesis and tillering in rice. Detailed analyses of a series of Os1900 promoter deletion mutations suggest that fertilization controls tiller number in rice through transcriptional regulation of Os1900, and that a few promoter mutations alone can increase tiller numbers and grain yields even under minor-fertilizer conditions, whereas a single defective os1900 mutation does not increase tillers under normal fertilizer condition. Such Os1900 promoter mutations have potential uses in breeding programs for sustainable rice production.

High Ambient Temperatures Inhibit Ghd7-Mediated Flowering Repression in Rice

The anticipation of changing seasons is crucial for reproduction in plants. Despite the broad cultivation area, the effects of ambient temperature on photoperiodic flowering are largely unknown in rice. Here, we first examined flowering time under four distinct conditions: short-day or long-day and high or low temperature, using cultivars, nearly isogenic lines, and mutants in rice. We also examined gene expression patterns of key flowering-time genes using the same lines under various conditions including temporal dynamics after light pulses. In addition to delayed flowering because of low growth rates, we found that photoperiodic flowering is clearly enhanced by both Hd1 and Ghd7 genes under low-temperature conditions in rice. We also revealed that PhyB can control Ghd7 repressor activity as a temperature sensor to inhibit Ehd1, Hd3a and RFT1 at lower temperatures, likely through a post-transcriptional regulation, despite inductive photoperiod conditions. Furthermore, we found that rapid reduction of Ghd7 messenger RNA (mRNA) under high-temperature conditions can lead to mRNA increase in a rice florigen gene, RFT1. Thus, multiple temperature-sensing mechanisms can affect photoperiodic flowering in rice. The rising of ambient temperatures in early summer likely contributes to the inhibition of Ghd7 repressor activity, resulting in the appropriate floral induction of rice in temperate climates.

Clinical outcomes of endoscopic submucosal dissection for early gastric cancer in remnant stomach or gastric tube

BACKGROUND AND STUDY AIMS

Little information exists regarding the optimal treatment of early gastric cancer (EGC) in a remnant stomach or gastric tube. The aim of this study was to assess the feasibility and clinical outcomes of endoscopic submucosal dissection (ESD) for EGC in a remnant stomach and gastric tube.

PATIENTS AND METHODS

Between September 2002 and December 2009, ESD was performed in 62 lesions in 59 patients with EGC in a remnant stomach (48 lesions) or gastric tube (14 lesions). Clinicopathological data were retrieved retrospectively to assess the en bloc resection rate, complications, and outcomes. Treatment results were assessed according to the indications for endoscopic resection, and were compared with those of ESD performed in a whole stomach during the same study period.

RESULTS

The en bloc resection rates for lesions within the standard and expanded indication were 100 % and 93 %, respectively. Postoperative bleeding occurred in five patients (8 %). The perforation rate was significantly higher (18 %, 11 /62) than that of ESD in a whole stomach (5 %, 69 /1479). Among the perforation cases, eight lesions involved the anastomotic site or stump line, and ulcerative changes were observed in five lesions. The 3-year overall survival rate was 85 %, with eight deaths due to other causes and no deaths from gastric cancer.

CONCLUSION

A high en bloc resection rate was achieved by ESD for EGC in a remnant stomach or gastric tube; however, this procedure is still technically demanding due to the high complication rate of perforation.

Extensive bleeding during surgical treatment for gingival overgrowth in a patient on haemodialysis--a case report and review of the literature

Before performing renal transplantation, a most important concern is to control any infection, including oral infections before transplantation. The bleeding diathesis of patients with uraemia is a significant clinical concern, especially when surgery is required. A 44-year-old female patient on haemodialysis was referred for evaluation of gingival overgrowth. The patient was planning a renal transplantation two months later. As the lesions were not considered successfully treatable before transplantation, a gingivectomy and teeth extraction was performed. In pre-operative examinations, an abnormal bleeding time was not detected and other coagulation tests were normal. Under general anaesthesia, 19 teeth were extracted and overgrown gingiva was removed. During the operation, extensive blood loss of 1650ml occurred and four units of concentrated red blood cells were transfused. This study suggests that patients with renal failure undergoing dental surgery require careful pre-surgical evaluation including assessment of their coagulation ability.

Histological study of rat masseter muscle following experimental occlusal alteration

It has been suggested that occlusal interference results in masticatory muscle dysfunction. In our previous study, occlusal interference reduced the rat masseter energy level during masticatory movements. The purpose of this study was to investigate the histological alterations of rat masseter muscles following experimental occlusal alteration with unilateral bite-raising. A total of eight male adult Wistar rats were equally divided into control and experimental groups. The experimental rats wore bite-raising splints on the unilateral upper molar. However, 4 weeks after the operation, the anterior deep masseter muscles were removed and then stained for succinic acid dehydrogenase (SDH), haematoxylin eosin (HE) and myofibrillar ATPase. Most of the muscle fibres in experimental rats remained intact, although partial histological changes were observed, such as extended connective tissue, appearance of inflammatory cells in the muscle fibres and existence of muscle fibres with central nuclei and central cores. Moreover, the fibre area-fibre frequency histograms of experimental muscle indicated a broad pattern than that of controls. These results indicated that occlusal interference caused histological changes in masseter muscles and that this may be related to the fact that the masseter energy level was reduced during masticatory movements in unilateral bite-raised rats.

HSP90 has neurite-promoting activity in vitro for telencephalic and spinal neurons of chick embryos

We purified a protein from the extract of denervated chick muscle. The protein had neurite-promoting activity in vitro for the chick telencephalic neurons and spinal neurons. Partial amino acid sequencing and immunoblotting revealed that the protein was chick heat shock protein 90 (HSP90). Commercially available bovine HSP90 and recombinant chick HSP90 expressed in Escherichia coli also showed the same activity. Since HSP10 (GroES) and HSP60 (GroEL) exhibited no activity for neurite outgrowth in the same culture, this activity was specific to HSP90 among the heat shock proteins.

Cherubism: diagnostic imaging and review of the literature in Japan

Cherubism is a nonneoplastic disease of bone characterized by clinical, bilateral, painless enlargements of the jaws that are said to give the patient a cherubic appearance. Cherubism may appear in solitary cases or in many members of the family, often in multiple generations. On radiography the lesions have the appearance of bilateral multilocular radiolucent areas. On histopathologic evaluation the lesions show proliferating fibrous connective tissue containing numerous multinucleated giant cells. Since it was first described by Jones in 1933, many cases have been documented without restriction to any one country or ethnic group, but only a few cases have been reported in Japan, apparently because it is rare here. We report a case of cherubism in a 15-year-old boy and review the Japanese literature.