NAL1 allele from a rice landrace greatly increases yield in modern indica cultivars

Increasing crop production is essential for securing the future food supply in developing countries in Asia and Africa as economies and populations grow. However, although the Green Revolution led to increased grain production in the 1960s, no major advances have been made in increasing yield potential in rice since then. In this study, we identified a gene, SPIKELET NUMBER (SPIKE), from a tropical japonica rice landrace that enhances the grain productivity of indica cultivars through pleiotropic effects on plant architecture. Map-based cloning revealed that SPIKE was identical to NARROW LEAF1 (NAL1), which has been reported to control vein pattern in leaf. Phenotypic analyses of a near-isogenic line of a popular indica cultivar, IR64, and overexpressor lines revealed increases in spikelet number, leaf size, root system, and the number of vascular bundles, indicating the enhancement of source size and translocation capacity as well as sink size. The near-isogenic line achieved 13–36% yield increase without any negative effect on grain appearance. Expression analysis revealed that the gene was expressed in all cell types: panicles, leaves, roots, and culms supporting the pleiotropic effects on plant architecture. Furthermore, SPIKE increased grain yield by 18% in the recently released indica cultivar IRRI146, and increased spikelet number in the genetic background of other popular indica cultivars. The use of SPIKE in rice breeding could contribute to food security in indica-growing regions such as South and Southeast Asia.The world’s population is expected to surpass 9 billion in 2050 (http://esa.un.org/unpd/ppp/index.htm). Most of this increase will occur in the developing countries of Asia and Africa. By 2035, a 26% increase in rice production will be essential to feed the rising population (1, 2). Rice (Oryza sativa L.) is a staple food of more than 3 billion people, mainly in Asia. Predominantly, indica cultivars are grown in southern China, Southeast Asia, and South Asia, occupying approximately 70% of the rice-producing area in the world, whereas japonica cultivars are grown mainly in East Asia (3, 4). Because of urbanization and industrialization, an increase in the yield of indica cultivars is a pressing need in Southeast and South Asia (5). Additionally, good grain quality (influencing market value) and high yield are essential for the adoption of new cultivars in local areas (6).The grain yield of rice is determined by spikelet number per panicle, panicle number per plant, grain weight, and spikelet fertility. Although many quantitative trait loci (QTLs) for yield components have been identified (www.gramene.org), few have so far been isolated. To date, at least nine genes or loci for yield-related traits in rice have been isolated from natural variation: Gn1a and APO1 for number of grains (7–9); GS3, GW2, and qSW5 for grain size (10–12); DEP1 and WFP for panicle architecture (13, 14); SCM2 for strong culm (15); and Ghd7 for late heading and number of grains (16). APO1, SCM2, and DEP1 increased grain yield in a japonica genetic background in field experiments (9, 13, 15). However, no novel cloned gene has been reported to increase grain yield in indica cultivars (17). Here, we identified a gene in a tropical japonica landrace and used the allele to increase the grain yield of modern indica cultivars at the crop level through a breeding concept developed by International Rice Research Institute (IRRI) breeders more than 20 y ago.In 1989, a breeding program for New Plant Type (NPT) rice was launched at IRRI to increase the yields of modern indica cultivars by using genetic material from tropical japonica landraces (18). Several Indonesian tropical japonica landraces—which are characterized by large panicles, large leaves, a vigorous root system, thick stems, and few unproductive tillers—have been used in international breeding programs. However, despite these features, the NPT cultivars yield less than modern indica cultivars, mainly because of low grain fertility and low panicle number (19, 20). To genetically dissect and elicit the valuable traits of NPT cultivars, we backcrossed the NPT cultivars including YP9 (IR68522-10-2-2) against modern indica cultivar IR64 to develop introgression lines (ILs) (Fig. S1). BC₃-derived ILs, which had favorable yield-related traits and few undesirable traits, were selected by field observation (21). Using the ILs, we identified 21 QTLs for yield components such as total spikelet number per panicle (TSN), grain weight, and panicle number. Among the QTLs, qTSN4, for high TSN, was commonly detected on the long arm of chromosome 4 in five NPT lines derived from different tropical japonica cultivars (22). Additionally, a near-isogenic line (NIL) for qTSN4 from YP9, derived from tropical japonica landrace Daringan with an IR64 genetic background, had more spikelets per panicle and more branches than IR64.In this study, we isolated the gene for qTSN4 through map-based cloning to facilitate its use in breeding. The phenotypic effects of the gene were validated in transgenic plants and by expression analysis. To confirm the effect on practical grain yield in the field, we evaluated yield and related traits by using NILs with genetic backgrounds of popular indica cultivars.     

Muscle strength,aerobic capacity and physical activity in independent ambulating children with lumbosacral spina bifida

Purpose. This cross-sectional study investigates deficits and associations in muscle strength, 6-minute walking distance (6MWD), aerobic capacity (VO_2peak), and physical activity (PA) in independent ambulatory children with lumbosacral spina bifida.

Method. Twenty-tree children participated (13 boys, 10 girls). Mean age (SD): 10.4 (±3.1) years. Muscle strength (manual muscle testing and hand-held dynamometry), 6MWD, VO_2peak (maximal exercise test on a treadmill), and PA (quantity and energy expenditure [EE]), were measured and compared with aged-matched reference values.

Results. Strength of upper and lower extremity muscles, and VO_2peak were significantly lower compared to reference values. Mean Z-scores ranged from ?1.2 to ?2.9 for muscle strength, and from ?1.7 to ?4.1 for VO2peak. EE ranged from 73 – 84% of predicted EE. 6MWD was significantly associated with muscle strength of hip abductors and foot dorsal flexors. VO_2peak was significantly associated with strength of hip flexors, hip abductors, knee extensors, foot dorsal flexors, and calf muscles.

Conclusions. These children have significantly reduced muscle strength, 6MWD, VO_2peak and lower levels of PA, compared to reference values. VO_2peak and 6MWD were significantly associated with muscle strength, especially with hip abductor and ankle muscles. Therefore, even in independent ambulating children training on endurance and muscle strength seems indicated.     

Perceptions, expectations, and attitudes about communication with physicians among Chinese American and non-Hispanic white women with early stage breast cancer

Purpose

Asian Americans have consistently reported poorer communication with physicians compared with non-Hispanic Whites (NHW). This qualitative study sought to elucidate the similarities and differences in communication with physicians between Chinese and NHW breast cancer survivors.

Methods

Forty-four Chinese and 28 NHW women with early stage breast cancer (stage 0-IIa) from the Greater Bay Area Cancer Registry participated in focus group discussions or individual interviews. We oversampled Chinese women because little is known about their cancer care experiences. In both interview formats, questions explored patients' experiences and feelings when communicating with physicians about their diagnosis, treatment, and follow-up care.

Results

Physician empathy at the time of diagnosis was important to both ethnic groups; however, during treatment and follow-up care, physicians' ability to treat cancer and alleviate physical symptoms was a higher priority. NHW and US-born Chinese survivors were more likely to assert their needs, whereas Chinese immigrants accepted physician advice even when it did not alleviate physical problems (e.g., pain). Patients viewed all physicians as the primary source for information about cancer care. Many Chinese immigrants sought additional information from primary care physicians and stressed optimal communication over language concordance.

Conclusions

Physician empathy and precise information were important for cancer patients. Cultural differences such as the Western emphasis on individual autonomy vs. Chinese emphasis on respect and hierarchy can be the basis for the varied approaches to physician communication we observed. Interventions based on cultural understanding can foster more effective communication between immigrant patients and physicians ultimately improving patient outcomes.     

Neurofibrillary tangles in the dentate granule cells of patients with Alzheimer’s disease,Lewy body disease and progressive supranuclear palsy

Recent studies have shown that the dentate granular cells of the hippocampus are affected in patients with Alzheimer’s disease (AD). To gain a better understanding of the cytoskeletal alterations in these cells, we carried out immunocytochemical and immunoelectron microscopic analysis of the dentate gyrus of patients with primary degenerative dementias, using a monoclonal antibody against paired helical filaments (TG3). This antibody labeled a large number of spherical inclusions in the dentate granule cells of patients with AD and its Lewy body variant (LBV). These inclusions consisted of straight tubular structures (about 18–25 nm in diameter), similar to those found in progressive supranuclear palsy (PSP). These inclusions, although in a smaller number, were also found in demented patients with PSP, but not in those with diffuse Lewy body disease or age-matched controls. These findings indicate that the neurofibrillary alterations in the dentate granule cells of patients with AD, LBV and PSP share cytoskeletal similarities. Received: 18 March 1996 / Revised, accepted: 4 July 1996     

All six rat gamma-crystallin genes are located on chromosome 9

The rat genome contains six genes for the lens-specific gamma-crystallins. Five of these genes are clustered; the location of the sixth gene is not known. To determine whether the sixth gene is located on the same chromosome as the gamma-crystallin gene cluster, a panel of mouse-rat hybrid cell lines, segregating rat chromosomes, was screened for the presence of gamma-crystallin sequences. We show here that the hybrid cell lines contain either all rat gamma-crystallin genes or none, indicating that all six genes map to the same chromosome. The presence of rat gamma-crystallin sequences in the hybrid cell lines was concordant only with the presence of rat chromosome 9, which therefore contains the rat gamma-crystallin genes.     

Primary leiomyoma of the liver

Summary The fourth known case of primary leiomyoma of the liver is described. This diagnosis depends on the exclusion of leiomyoma at other intraabdominal sites and careful histologic review to exclude malignant change. In the presented case, multiple noninvasive imaging modalities failed to allow a tissue specific diagnosis, although magnetic resonance imaging of the liver did add useful information. For this problem, hepatic lobectomy is both diagnostic and curative.     

A roadmap to disentangle the molecular etiology of schizophrenia

Schizophrenia is a severe mental disorder striking mainly young adults and leading to life-long disability in a substantial portion of the sufferers. On the other hand, substantial knowledge about its etiology and pathogenesis is still lacking. Therefore the European Science Foundation (ESF) sponsored a meeting of a panel of European experts on schizophrenia research to discuss the state of art and future perspectives of key topics in this area. The fields covered genetics, epidemiology, animal models, molecular neuropathology and imaging. This was a first step to establish a network of European groups dedicated to Schizophrenia research. The coming calls of the frame work program will be used to strengthen this network in order to achieve substantial progress in understanding and treating this devastating illness.     

Naturally occurring leukemia viruses in H-2 congenic C57BL mice. II. Antibody response to viral envelope antigens

In C57BL mice milk-borne infection with B-tropic murine leukemia virus (V+ denoting positive for milk-transmitted B-tropic virus and V- denoting negative for milk-transmitted B-tropic virus) was accompanied by an antibody response against viral envelope antigens (VEA). Milk transmission of virus led to higher virus titers and lymphoma incidence in B10.A (H-2a) mice than in B10 (H-2b) mice, and the latter strain produced higher titers of anti-VEA antibodies than did the former. H-2 control of the antivirus-antibody response was confirmed in the (B10.A V+ X B10 V+)F2 cross. B10 V+ mice produced both IgM and IgG antibodies, whereas in the sera of B10.A V+ mice only IgM antibodies were demonstrable. The production of IgG and high-titer IgM antibodies to VEA was dominant in (B10.A V+ X B10 V+)F1 animals. The failure of B10.A V+ mice to produce IgG antibodies against VEA was not due to an intrinsic defect of helper T-cell function because these mice produced IgG antivirus antibodies after sc immunization with killed viral vaccine. Furthermore, in B10.A mice without milk-transmitted virus (B10.A V- subline), expression of genetically transmitted virus upon aging was associated with the production of IgG antibodies to VEA. The combined data were compatible with the existence of an H-2-linked dominant immune-response gene regulating the antibody response to milk-transmitted murine leukemia virus.