An NLR paralog Pit2 generated from tandem duplication of Pit1 fine-tunes Pit1 localization and function.

NLR family proteins act as intracellular receptors. Gene duplication amplifies the number of NLR genes, and subsequent mutations occasionally provide modifications to the second gene that benefits immunity. However, evolutionary processes after gene duplication and functional relationships between duplicated NLRs remain largely unclear. Here, we report that the rice NLR protein Pit1 is associated with its paralogue Pit2. The two are required for the resistance to rice blast fungus but have different functions: Pit1 induces cell death, while Pit2 competitively suppresses Pit1-mediated cell death. During evolution, the suppression of Pit1 by Pit2 was probably generated through positive selection on two fate-determining residues in the NB-ARC domain of Pit2, which account for functional differences between Pit1 and Pit2. Consequently, Pit2 lost its plasma membrane localization but acquired a new function to interfere with Pit1 in the cytosol. These findings illuminate the evolutionary trajectory of tandemly duplicated NLR genes after gene duplication.

Morphology and morphometry of the human early foetal brain: A three-dimensional analysis.

Morphometric analyses in the early foetal phase (9-13 postconceptional week) are critical for evaluating normal brain growth. In this study, we assessed sequential morphological and morphometric changes in the foetal brain during this period using high-resolution T1-weighted magnetic resonance imaging (MRI) scans from 21 samples preserved at Kyoto University. MRI sectional views (coronal, mid-sagittal, and horizontal sections) and 3D reconstructions of the whole brain revealed sequential changes in its external morphology and internal structures. The cerebrum's gross external view, lateral ventricle and choroid plexus, cerebral wall, basal ganglia and thalamus, and corpus callosum were assessed. The development of the cerebral cortex, white matter microstructure, and basal ganglia can be well-characterized using MRI scans. The insula became apparent and deeply impressed as brain growth progressed. A thick, densely packed cellular ventricular/subventricular zone and ganglionic eminence became apparent at high signal intensity. We detected the emergence of important landmarks which may be candidates in the subdivision processes during the early foetal period; the corpus callosum was first detected in the sample with crown-rump length (CRL) 62 mm. A primary sulcus on the medial part of the cortex (cingulate sulcus) was observed in the sample with CRL 114 mm. In the cerebellum, the hemispheres, posterolateral fissure, union of the cerebellar halves, and definition of the vermis were observed in the sample with CRL 43.5 mm, alongside the appearance of a primary fissure in the sample with CRL 56 mm and the prepyramidal fissure in the sample with CRL 75 mm. The volumetric, linear, and angle measurements revealed the comprehensive and regional development, growth, and differentiation of brain structures during the early foetal phase. The early foetal period was neither morphologically nor morphometrically uniform. The cerebral proportion (length/height) and the angle of cerebrum to the standard line at the lateral view of the cerebrum, which may reflect the growth and C-shape formation of the cerebrum, may be a candidate for subdividing the early foetal period. Future precise analyses must establish a staging system for the brain during the early foetal period. This study provides insights into brain structure, allowing for a correlation with functional maturation and facilitating the early detection of brain damage and abnormal development.

Difficulties in measles elimination: prevalence of measles antibodies before and after mass vaccination campaign in Laos.

Responding to the declaration of regional polio eradication in 2000, Western Pacific Region (WPR) has been strengthening the efforts for measles elimination. Nevertheless, we questioned the feasibility of the measles elimination in Laos, where measles was still endemic. This study was undertaken with the aim to examine the impact of mass measles vaccination campaign, by comparing the prevalence of measles antibodies between before and after the campaign in 2000, among the children aged 9 months to 4 years in the two pilot sites. The constraints of mass vaccination campaign have been explored in this study. It was also suggested that more efforts should be put on reconstruction of the existing routine immunization service in Laos, which had been weakened by aggressive eradication programme.

Differential workloads of boys and girls in rural Nepal and their association with growth.

In developing countries, heavy workloads of women adversely affect their nutritional status and that of their children. Little is known, however, about the effect of children's heavy workloads on their own well-being. In Nepal, girls are expected to help their mothers in time-consuming and energy-demanding tasks from an early age. The aim of this study was to compare work patterns and anthropometric status of boys and girls age 6-17 years in western rural Nepal. It was hypothesized that girls would work longer and harder than boys and would have poorer growth status. It was also anticipated that children's work patterns might differ between highland and lowland areas. Two study sites were therefore chosen: one in the hills and the other in the lowland terai. A time allocation study was conducted for 237 children. They were observed continuously from 7:00 AM to 7:00 PM to determine the time spent in light, moderate, and heavy activities. Body weights and heights were also measured. On average, girls worked twice as long as boys (5.8 vs. 2.8 h/day, P < 0.001) and undertook more heavy work (1.5 vs. 0.7 h/day, (P < 0.001), but they did not have poorer anthropometric status. Children in the hills worked longer hours and did heavier work than those in the terai and were more stunted in growth.