TEMPORAL VARIATION IN RADIOCESIUM CONCENTRATIONS IN WATERS OF THE NATSUI AND SAME RIVERS, SOUTH FUKUSHIMA PREFECTURE, JAPAN FROM 2011 TO 2020.

In order to determine the long-term impacts of radiocesium contamination on ecosystems in watersheds and coastal areas following the Fukushima Daiichi Nuclear Power Plant accident in March 2011, it was important to monitor the transport behavior of radiocesium from an early stage. In this study, conducted from July 2011 to October 2020, we carried out field research along the Natsui and Same rivers running through watersheds in the south of Fukushima Prefecture, Japan, in which there had been a relatively low accumulation of radiocesium. We found that under normal flow conditions, the total (dissolved + particulate phase) activity of 137Cs decreased with increasing time following the accident. However, the water samples collected after rain events showed higher activity of up to 895 mBq l-1 with a higher percentage (>92% of total) of the particulate phase. These findings indicate that radiocesium deposited on the ground surface is predominantly transported in the particulate phase from watersheds to rivers via precipitation. The decontamination process, which was performed in the farmland during December 2014 to March 2015 and in forest during February 2013 to April 2014, was small effects of the transport of 137Cs. Under normal flow conditions, total 137Cs activity was largely determined by the suspended solids (SS) concentration and/or 137Cs concentration in the SS.

Novel mating type-dependent transcripts at the mating type locus in Magnaporthe oryzae.

The mating type locus (MAT1) of Magnaporthe oryzae has similar structural organization to MAT in other ascomycetes and encodes the mating type genes MAT1-1-1 with an alpha-box motif and MAT1-2-1 with an HMG-box motif in the MAT1-1 and MAT1-2 idiomorphs, respectively. Sequence and expression analyses of the MAT1 locus indicated a second open reading frame (ORF), MAT1-1-2, in the MAT1-1 idiomorph, and novel mating-type dependent ORFs (MAT1-1-3 and MAT1-2-2) at the locus. The MAT1-1-3 ORF initiated within the MAT1-1 idiomorph while the MAT1-2-2 ORF initiated at the border of the MAT1-2 idiomorph with both ORFs sharing most of their reading frames in the MAT1 flanking region. This suggests that the encoded proteins (MAT1-1-3 and MAT1-2-2) should be similar in their primary structures but can be distinguished by distinct N-termini with amino acids of 1 and 32, respectively, in each mating type. A CT dinucleotide repeat, (CT)n, present in the upstream region of MAT1-1-3, was polymorphic among the isolates.