Analysis of whole Y-chromosome sequences reveals the Japanese population history in the Jomon period

UTokyo FOCUS Press releases "Archaeological mystery solved with modern genetics : Y chromosomes reveal population boom and bust in ancient Japan" https://www.u-tokyo.ac.jp/focus/en/press/z0508_00056.htm

Architecture of the complete oxygen-sensing FixL-FixJ two-component signal transduction system

The symbiotic nitrogen-fixing bacterium Bradyrhizobium japonicum is critical to the agro-industrial production of soybean because it enables the production of high yields of soybeans with little use of nitrogenous fertilizers. The FixL and FixJ two-component system (TCS) of this bacterium ensures that nitrogen fixation is only stimulated under conditions of low oxygen. When it is not bound to oxygen, the histidine kinase FixL undergoes autophosphorylation and transfers phosphate from adenosine triphosphate (ATP) to the response regulator FixJ, which, in turn, stimulates the expression of genes required for nitrogen fixation. We purified full-length B. japonicum FixL and FixJ proteins and defined their structures individually and in complex using small-angle x-ray scattering, crystallographic, and in silico modeling techniques. Comparison of active and inactive forms of FixL suggests that intramolecular signal transduction is driven by local changes in the sensor domain and in the coiled-coil region connecting the sensor and histidine kinase domains. We also found that FixJ exhibits conformational plasticity not only in the monomeric state but also in tetrameric complexes with FixL during phosphotransfer. This structural characterization of a complete TCS contributes both a mechanistic and evolutionary understanding to TCS signal relay, specifically in the context of the control of nitrogen fixation in root nodules

〈Cases Reports〉Recurrent focal intestinal perforation in extremely-low-birth-weight infant

[Abstract] In recent years, the incidence of focal intestinal perforation (FIP) has been increasing, as the survival rate of extremely-low-birth-weight(ELBW) infants has been rising. We present a case of an ELBW infant who suffered three recurrences of FIP in a very short period of time. The patient was a female infant who was born at 24 weeks and 2 days of gestation, with a birth weight of 579 g. On her 22^nd day of life, abdominal X-rays revealed free air, which suggested intestinal perforation, and an intraperitoneal drainage tube was placed. Intraperitoneal lavage was performed on day 28 of life,and the drained fluid was turbid with feces, suggesting a recurrence of perforation. On day 30 of life, laparotomy revealed a perforation of approximately 1cm in diameter located at 6 cm from the ileocecum on the oral side. The X-ray taken on day 34 again revealed free air, and, through another laparotomy, a new perforation was found at about 15 cm from the stoma on the oral side. This case provides suggestions that may shed light on our approach to determine the pathogenesis of FIP, especially since no other case of FIP recurring three times has ever been reported