Inversion Polymorphisms in Populations of Drosophila Melanogaster in the South-West Islands of Japan: Comparisons with the Mainland Populations

Natural populations of D. melanogaster newly collected from the South-West Islands of Japan were examined for the frequencies of inversions, and the results, together with previous data, were compared with those of the mainland populations. The four Common cosmopolitan inversions (2Lt, 2RNS, 3LP, 3RP) were detected from most of the populations with higher frequencies. The three Rare cosmopolitan inversions (3LM, 3RC, 3RMo), three Quasi cosmopolitan inversions (2LA, 3LY, 3RK) and two new Endemic inversions were also found but with lower frequencies. Some of the South-West Island populations still maintained higher levels of inversion polymorphisms compared to the mainland populations, while others lost the polymorphisms to various degrees. The South-West Island populations were characterized by the higher frequency of In(3L)P. The ratios of In(3L)P/In(3R)P in the South-West Islands are significantly higher than those of the mainland populations, suggesting that the In(3L)P is relatively adaptive in the South-West Islands.     

Characterization and prediction of linker sequences of multi-domain proteins by a neural network

In this paper, we describe a neural network analysis of sequences connecting two protein domains (domain linkers). The neural network was trained to distinguish between domain linker sequences and non-linker sequences, using a SCOP-defined domain library. The analysis indicated that a significant difference existed between domain linkers and non-linker regions, including intra-domain loop regions. Moreover, the resulting Hinton diagram showed a position-dependent amino acid preference of the domain linker sequences, and implied their non-random nature. We then applied the neural network to predict domain linkers in multi-domain protein sequences. As the result of a Jack-knife test, 58% of the predicted regions matched actual linker regions (specificity), and 36% of the SCOP-derived domain linkers were predicted (sensitivity). This prediction efficiency is superior to simpler methods derived from secondary structure prediction that assume that long loop regions are putative domain linkers. Altogether, these results suggest that domain linkers possess local characteristics different from those of loop regions.     

Development of glycosylated human interleukin-1 alpha, neoglyco IL-1 alpha, by coupling with D-galactose monosaccharide: biological activities in vitro

In the previous study, galactose with C9 spacer was chemically coupled to human recombinant (rh) IL-1 alpha in order to study the effect of glycosylation on its activities, and to develop IL-1 with less deleterious effects. In this study we examined a variety of IL-1 activities in vitro, including proliferative effect on T cells, antiproliferative effect on myeloid leukemic cells and melanoma cells, stimulatory effects on IL-6 synthesis by melanoma cells and PGE2 synthesis by fibroblast cells Galactose-introduced IL-1 alpha (Gal-IL-1 alpha) exhibited reduced activities from 10 to 10000 times compared with unmodified IL-1 alpha in all the activities performed in vitro. The competitive binding of 125I-IL-1 alpha to mouse T cells and pre-B cells with unlabeled IL-1 alpha s suggests a decrease in binding affinities of Gal-IL-1 alpha to both type I and type II IL-1 receptors. Therefore, reduced activities of Gal-IL-1 alpha are due, at least partially, to the decrease in their receptor binding affinities.     

Evidence of an increased risk of hearing loss in heterozygous carriers in a Wolfram syndrome family

Wolfram syndrome (MIM 222300) is characterized by juvenile-onset diabetes mellitus and optic atrophy. Previous linkage analyses in the United States and UK families have indicated that the gene for Wolfram syndrome (WFS) is localized on the short arm of chromosome 4. We herein confirm the linkage of the WFS locus to D4S3023 on 4p with a two-point LOD score of 3.42 in a large Japanese family with Wolfram syndrome. Multipoint linkage analysis revealed the maximum LOD score of 4.82 between D4S3023 and D4S394. We also evaluated putative health risks in carriers by multiple logistic analysis with independent variables, age, gender, and numbers of affected haplotypes and with dependent variables, such as hearing loss, diabetes mellitus, polyuria, incontinence, psychological illness, and visual acuity. The results showed that the putative disease haplotype increased a risk of hearing loss (odds ratio =35.68, 95% confidence interval =4.12–308.95) and diabetes mellitus (odds ratio =7.57, 95% confidence interval =2.03–28.23) independently. This is the first report of an increased health risk of illness in carriers, other than for psychiatric disease. Received: 23 June 1998 / Accepted: 15 August 1998     

Increases in Fragmented Glial Fibrillary Acidic Protein Levels in the Spinal Cords of Patients with Amyotrophic Lateral Sclerosis

Using one-dimensional polyacrylamide gel electrophoresis, we analyzed protein fractions extracted from the spinal cords of patients with amyotrophic lateral sclerosis (ALS). Several protein bands with molecular weights of 35–55 kDa were stained with Coomassie brilliant blue much more intensely in the ALS than in the non-ALS spinal cord. Glial fibrillary acidic protein (GFAP) immunoreactivity showed a significant decrease of 50 and 45 kDa band and increase in fragmented 36 and 37 kDa bands, which represented GFAP fragments devoid of 59 and 40 residues from the N-terminal, respectively, as determined by protein sequence analysis. Immunohistochemical examination of ALS spinal cord transections demonstrated increased GFAP-stained astrocytes in the shrunken ventral horn with massive degeneration of motoneurons. These results will provide new insight into the possible role of astrocytes in the pathophysiology and/or pathogenesis of ALS.     

Isolation and characterization of a rice homebox gene, OSH15

In many eukaryotic organisms including plants, homeobox genes are thought to be master regulators that establish the cellular or regional identities and specify the fundamental body plan. We isolated and characterized a cDNA designated OSH15 (Oryza sativa homeobox 15) that encodes a KNOTTED-type homeodomain protein. Transgenic tobacco plants overexpressing the OSH15 cDNA showed a dramatically altered morphological phenotype caused by disturbance of specific aspects of tobacco development, thereby indicating the involvement of OSH15 in plant development. We analyzed the in situ mRNA localization of OSH15 through the whole plant life cycle, comparing the expression pattern with that of another rice homeobox gene, OSH1. In early embryogenesis, both genes were expressed as the same pattern at a region where the shoot apical meristem would develop later. In late embryogenesis, the expression pattern of the two genes became different. Whereas the expression of OSH1 continued within the shoot apical meristem, OSH15 expression within the shoot apical meristem ceased but became observable in a ring shaped pattern at the boundaries of some embryonic organs. This pattern of expression was similar to that observed around vegetative or reproductive shoots, or the floral meristem in mature plants. RNA in situ localization data suggest that OSH15 may play roles in the shoot organization during early embryogenesis and thereafter, OSH15 may be involved in morphogenetic events around the shoot apical meristem.     

Factors influencing otolith strontium/calcium ratios in Anguilla japonica elvers

The effects of temperature and salinity on the concentration ratios of strontium (Sr) to calcium (Ca) within the sagittal otoliths of elvers of the Japanese eel, Anguilla japonica, were studied by spot analysis using a wavelength dispersive X-ray electron microprobe. A total of 340 elvers were used: 100 elvers were reared for 15 days under various salinity conditions (freshwater, one-third seawater, two-thirds seawater and pure seawater at 22 °C; 240 elvers were reared for 58 days under various water temperature conditions (12, 17, 22, 27 °C) in either freshwater or pure seawater. Otolith Sr/Ca ratios were found to be positively correlated with water salinity. On the other hand, the Sr/Ca ratios were not found to be significantly different among the various temperature groups. The above results strongly suggest that the physiological mechanism of incorporation of Sr and Ca within the otolith of an eurythermal fish, Japanese eel, does not change within this range of temperatures (12–27 °C).     

Determination of the freshwater mark in otoliths of Japanese eel elvers using microstructure and Sr/Ca ratios

The microstructure, in particular checks within the otolith edge, of Anguilla japonica glass-eels and elvers and changes in otolith Sr/Ca ratios were examined to ascertain the environmental history of the eels, especially with regard to the time when glass-eels entered the river, and as a benchmark for count daily increments. The percentage of glass eels and elvers with checks and the mean number of checks within the otoliths of glass-eels caught at four localities, Tosa Bay off Tosa City, the mouth of the Gokase River, the mouth of the Saigo River and the dam of the Tsuri River were 0% (0), 15.0% (0.2), 51.6% (1.0) and 100.0% (4.2), respectively. The Sr/Ca ratios and Sr content peaked in the region where checks were formed and the values decreased rapidly towards the edge of the checks; on the other hand, these decreased gradually in the otolith when checks were not formed. These checks were estimated to be formed by stress when the glass-eels were affected by ambient fresh water within the river. The innermost check was called the freshwater mark in the present study and this mark may be useful as a benchmark in studying the growth history of the eel before and after entering freshwater.