Mutations in the Norrie disease gene: a new mutation in a Japanese family.
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Adolescent↗
Biomedical subjects
Y Hotta
Publications and source records attributed to Y Hotta.
Clinical features of Japanese Leber's hereditary optic neuropathy with 11778 mutation of mitochondrial DNA.
The G to A transition of nucleotide position (nt) 11778 of mitochondrial DNA (mtDNA) has been frequently observed in Japanese Leber's hereditary optic neuropathy (LHON) cases. Therefore, we performed a multi-institutional study in Japan of LHON cases with this 11778 mutation of the mtDNA. Genetic and clinical data on 108 cases (90 affected and 18 carriers) in 79 unrelated families were obtained from 64 Japanese institutions. Detection of the nt11778 mutation was performed using restriction enzymes (74 cases) or dot blot with allele specific oligonucleotide (34 cases). Heteroplasmy was observed in 13 of the 90 affected cases and in 8 of the 18 carrier cases. Forty-five families had family history of LHON (44 maternal inheritance, 1 undetermined), and in 28 families (35.9%) there were isolated cases. The male-to-female ratio in the affected was 82:7 (92.1% male). The age at onset of visual loss ranged from 7 to 59 years (average: 23.4 years). All cases had bilateral involvement except one case with a blind eye resulting from ocular infection during childhood. Onset interval between the two eyes ranged from simultaneous to 17 months (average: 2.5 months), in 91.3% of cases being under 6 months. Visual acuity was 0.1 or worse in 152 (85.9%) of 177 eyes, only 6 eyes showing over 0.5. Progression of visual loss ranged from 0 to 48 months (average: 6.2 months). Central visual field abnormality was observed in 162 eyes (96.4%) of 168 eyes. Nonsuspect fundus in the ophthalmoscopic examination constituted 22.8% of eyes. Systemic corticosteroid was given to 45 (52.9%) of 85 cases and visual acuity was improved in only 2 cases (4.4%). Arrhythmia, neurological and muscular abnormality were observed as rare general complications. The present survey indicates that the male-to-female ratio is higher than the previous Japanese LHON statistics and that the visual outcome is better than in American LHON cases with the 11778 mutation.
Adolescent↗
[A study on the rhodopsin gene in Japanese retinitis pigmentosa--screening of mutation by restriction endonucreases and frequencies of DNA polymorphisms].
We analyzed 11 sites of the rhodopsin gene using polymerase chain reaction (PCR) amplification and restriction endonucleases in 30 unrelated Japanese patients with autosomal dominant retinitis pigmentosa (ADRP). No point mutation was found in any patient. The frequencies of the single nucleotide (nt) substitution at nt 269, nt 5145 and nt 5321 were examined in three groups, 38 unrelated patients with ADRP, 23 patients with autosomal recessive retinitis pigmentosa (ARRP), and 67 normal controls. There was no significant difference in the frequencies of substitution among these three groups. The frequencies of A269G, G5145A, and C5321A were 52%, 36%, and 5%, respectively. These values were different from those of the American population. The polymorphisms, A269G and G5145A, are useful as DNA makers for linkage analysis.
Asian People↗
Direct measurement of increased myocardial cellular 23Na NMR signals in perfused guinea-pig heart induced by dihydroouabain and grayanotoxin-I.
The effects of the cardiac glycoside dihydroouabain (DHO), and the ericaceous toxin grayanotoxin-I (GTX-I) on myocardial cellular sodium (Nai) concentrations were investigated using sodium-23 nuclear magnetic resonance (23Na NMR) spectroscopy at 30 degrees C in isolated perfused guinea-pig hearts. The Nai NMR signals from perfused Langendorff heart preparations were obtained by the modified inversion recovery (IR) method based on the previous observation that the spin-lattice relaxation time (T1) of the Nai (25 or 34 msec at 8.46 Tesla (T)) is much faster than that of extracellular sodium (64 msec at 9.4 T). Nai was estimated from the calibration curve of the frequency area of the 23Na NMR FT spectra plotted against the standard Na concentration. The Nai concentration of the heart increased concomitantly with the positive inotropic effects (PIE) of DHO, GTX-I and monensin (MON). The cumulative sequential addition of DHO (5 x 10(-6) M), GTX-I (7 x 10(-8) M) and MON (5 x 10(-6) M), each of which alone induced no appreciable PIE, produced a 22% elevation in Nai concentration relative to that of the control (100%) accompanying a PIE of 44%. The mechanism of this Nai elevation induced by combinational addition of DHO, GTX-I and MON may be mediated as follows: GTX-I increases the net Na-influx via Na+ channels; DHO inhibits the pumping out of Na+ from the cell; and MON transports external Na+ into the cell, acting as a sodium ionophore. Consequently, these drugs act synergistically to increase the Nai, thereby increasing the intracellular Ca2+ concentration via Na(+)-Ca2+. exchange.
Animals↗
Determination of a putative recombinogenic human hepatitis B virus sequence and its binding cellular protein.
Previously, we reported that C4BglII196, a 196-base pair subgenomic fragment of hepatitis B virus (HBV) covering its precore region, enhances in vitro recombination in the presence of extracts from actively dividing cells (Hino, O., et al. Proc. Natl. Acad. Sci. USA, 88:9248-9252, 1991). The results indicated that HBV may play some role in causing genomic instability during chronic hepatitis. In the present study, we showed that 15AB, a 60-base pair subgenomic fragment of HBV DNA (nucleotides 1855-1914) within C4BglII196 is indispensable for enhancement of in vitro recombination, using the mouse leukemia cell 70Z/3, as the cellular extract source. 15AB, thought to be the encapsidation signal of HBV pregenomic RNA and U5-like retrovirus long terminal repeat, was found to bind specifically to an approximately 100 kDa protein of 70Z/3 by southwestern blotting. Production of a mutation in the 15AB region decreased both its binding activity to 100 kDa protein and the in vitro recombination activity. Our present results thus suggest that 15AB might be a recombinogenic sequence and the 100-kDa protein may be a putative recombinogenic protein in eukaryotes, triggering genomic instability and facilitating carcinogenesis.
Base Sequence↗
Apoptosis of murine large intestine in acute graft-versus-host disease after allogeneic bone marrow transplantation across minor histocompatibility barriers.
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Acute Disease↗
Isolation and characterization of a gene for a ryanodine receptor/calcium release channel in Drosophila melanogaster.
The nucleotide sequence of a 25.7 kilobase Drosophila melanogaster genomic DNA segment containing a gene for a ryanodine receptor/calcium release channel homologue has been determined. Computer analysis and partial cDNA cloning revealed 26 exons comprising the protein-coding sequence in this gene. The predicted protein is homologous in amino acid sequence and shares characteristic structural features with the mammalian ryanodine receptors. In blot hybridization analysis, a approximately 16 kilobase RNA species was identified abundantly in a 6-12 h embryo as the transcript from this gene. In situ hybridization to polytene chromosomes indicated that this gene locates at band position 44F on the second chromosome.
Amino Acid Sequence↗
Developmental regulation of islet-1 mRNA expression during neuronal differentiation in embryonic zebrafish.
Islet-1 (Isl-1) is a LIM domain/homeodomain-type transcription regulator that has been originally identified as an insulin gene enhancer binding protein. Isl-1 is also expressed by subsets of neurons in the central nervous system of rat and chick embryos. We have cloned the Isl-1 cDNA from zebrafish and examined its expression pattern using in situ hybridization to whole-mount embryos. Isl-1 mRNA first appears immediately after gastrulation in the polster, the cranial ganglia, and in Rohon-Beard neurons and ventromedial cells of the spinal cord. The expression by the ventromedial cells is segmentally repeated and becomes restricted to the one or two cells slightly anterior to the segment borders. Double staining by in situ hybridization and an antibody which stains most axons suggested that these segmentally distributed cells may be either the rostral primary motoneuron (RoP) or middle primary motoneuron (MiP). This raises a possibility that Isl-1 may be involved during determination of subtype identities of the primary motoneurons. Furthermore, the specific Isl-1 mRNA expression in the spinal cord is under the control of the somites, since mutant embryo with defective somite failed to maintain this pattern.
Amino Acid Sequence↗
Identification and cloning of an mRNA coding for a germ cell-specific A-type lamin in mice.
The nuclear lamins are karyoskeletal proteins which have important functions, such as maintaining nuclear envelope integrity and organizing high order nuclear structure during mitosis in higher eukaryotes. In somatic mammalian cells, the A-type and B-type lamins, composed of lamins A and C and lamins B1 and B2, are major components of the nuclear lamina. However, A-type lamins have as yet not been identified in germ cells and undifferentiated embryonic cells. Here we report the cloning of a new 52-kDa A-type lamin from mouse pachytene spermatocytes, termed lamin C2 because of its similarities with lamin C. It has a sequence identical to that of lamin C except that the N-terminal segment, containing the head and the alpha-helical coil 1A domains, is replaced with a short non-alpha-helical stretch of amino acids. In mice, lamin C2 was found to be specifically expressed in germ cells. This specific expression and unique structure suggests a role for lamin C2 in determining the organization of nuclear and chromosomal structures during spermatogenesis.
Amino Acid Sequence↗
Identification and characterization of genes induced during sexual differentiation in Schizosaccharomyces pombe.
Five cDNA clones, harboring genetic messages preferentially expressed during the sexual differentiation process, were isolated from a cDNA library of Schizosaccharomyces pombe by subtractive screening. Transcription of the corresponding genes, termed isp3, 4, 5, 6, and 7, was dependent on nitrogen starvation and their induction occurred at several stages of spore formation. Analysis of the cDNA primary structures revealed a capacity for the coding of polypeptides of 19.2 kDa, 88.3 kDa, 60.1 kDa, 49.7 kDa, and 43.8 kDa, respectively. The translated amino-acid sequences of isp5 and isp6 were found to show significant similarities to those of amino-acid permeases and proteinase B of Saccharomyces cerevisiae, respectively. Disruption of isp6 arrested the cell cycle prior to conjugation and caused a drastic blocking effect on spore formation.
Amino Acid Sequence↗
cDNA cloning and functional characterization of a meiosis-specific protein (MNS1) with apparent nuclear association.
It is well known that cytoskeleton and karyoskeleton proteins are associated with changes in cell shape and with the rearrangement of the dynamic structures involved in cell division and motility. In higher vertebrates, there are three major skeletal protein groups: microfilaments, microtubules and intermediate filaments, each representing a multigene family. Some of these skeletal proteins are expressed in a temporally- and spatially-specific fashion, and they establish cell-specific cytoplasmic and nucleoplasmic organization during development. Here we report the cDNA cloning of a novel 60 kDa skeletal protein from mouse spermatocytes, termed MNS 1 (meiosis-specific nuclear structural protein), whose computer-predicted protein configuration indicates long alpha-helical coiled-coil domains flanked by non-helical terminal domains. Functional characterization of MNS1 by ectopic expression in culture cells indicated that it is a detergent- and high salt-resistant skeletal protein which is involved in organization of the nuclear or perinuclear architecture. The MNS1 protein is specifically expressed at the pachytene stage during spermatogenesis, so that its function may involve the determination and maintenance of the appropriate nuclear morphology during meiotic prophase.
Amino Acid Sequence↗
Characterization of cDNAs induced in meiotic prophase in lily microsporocytes.
To identify and analyze genes functioning during reproductive cell formation in higher plants, cDNAs harboring the messages induced in meiotic prophase were isolated and characterized. A cDNA library constructed from microsporocytes in meiotic prophase of Lilium longiflorum was screened with a subtraction probe specific to meiotic prophase. Clones selected were classified into 18 groups by cross hybridization and partial sequencing. Northern blot analysis revealed that the transcripts corresponding to the respective cDNA groups began accumulating at the early stages of meiosis and exhibited clone-specific profiles during meiosis and the spore formation process. The amino acid sequences of the predicted gene products showed similarity with known gene products, e.g. heat shock proteins, serine proteases in Bacillus, and RAD 51 gene product in yeast. Half of the putative gene products had hydrophobic N-terminal regions, suggesting that they may function as signal peptides.
Amino Acid Sequence↗
Acute retinal necrosis syndrome associated with herpes simplex keratitis.
BACKGROUND: Although acute retinal necrosis (ARN) syndrome is caused by a herpes group virus, association of herpetic keratitis with ARN syndrome is uncommon. A case of unilateral ARN syndrome with herpes simplex keratitis is discussed. METHODS: A 40-year-old man developed unilateral keratitis, necrotic retinitis, retinal vasculitis, vitritis, and iritis consistent with ARN syndrome 1 month after treatment for ipsilateral facial nerve palsy and auricular herpetic vesicles (Tolosa-Hunt syndrome). Impression cytologic examination of the corneal epithelial ulcer that developed concurrent with the intraocular findings and of the aqueous humor (obtained by paracentesis) was performed. RESULTS: Cells that reacted with anti-herpes simplex virus type 1 (HSV-1) antibody were detected on impression cytology, and DNA fragments corresponding to the HSV-1 DNA sequence were detected in the aqueous humor. CONCLUSION: This case shows that ARN syndrome may, on rare occasions, be associated with herpes keratitis secondary to HSV-1.
Adult↗
Drosophila retinal degeneration A gene encodes an eye-specific diacylglycerol kinase with cysteine-rich zinc-finger motifs and ankyrin repeats.
The Drosophila visual mutant, carrying the retinal degeneration A gene (rdgA), has photoreceptor cells that degenerate within a week after eclosion. Morphological studies suggested that this mutant harbors abnormalities in membrane turnover of the photoreceptor cells. Biochemically, the rdgA mutant lacks an eye-specific and membrane-associated diacylglycerol kinase (DGK; EC 2.7.1.107) activity in a gene-dosage-dependent manner, suggesting that rdgA gene encodes a DGK. We report the molecular cloning and characterization of a DGK gene, which maps to the rdgA locus. This gene, designated as DGK2, has a single open reading frame that encodes 1454 amino acids. Like porcine DGK, DGK2 has two cysteine-rich zinc-finger motifs as well as a DGK catalytic domain. The DGK2 protein contains four ankyrin-like repeats at the C-terminal region, suggesting that DGK2 is likely anchored to the membrane or cytoskeleton. Northern blot analysis and tissue in situ hybridization to adult sections revealed that DGK2 is expressed exclusively in the adult retina and that the amount of its mRNA is reduced in some of the rdgA mutant alleles. Furthermore, in two rdgA alleles, rdgA1 and rdgA2, nonsense and missense mutations occur within their DGK2 gene, respectively. Thus, we conclude that rdgA encodes an eye-specific DGK, the absence of which leads to rhabdomere degeneration due to defective phospholipid turnover.
Amino Acid Sequence↗
Clinical features of autosomal dominant retinitis pigmentosa with rhodopsin gene codon 17 mutation and retinal neovascularization in a Japanese patient.
A 49-year-old Japanese man had autosomal dominant retinitis pigmentosa with a point mutation in codon 17 of the rhodopsin gene, resulting in a threonine-to-methionine change, and retinal neovascularization in both eyes. Pigmentary degeneration mainly in the inferior area of the fundus, and severe loss in the upper portion of the visual field were observed. Moderately preserved rod and cone functions were demonstrated by electroretinograms. These findings differed from those of Japanese and white patients with autosomal dominant retinitis pigmentosa with a codon 347 mutation and were almost the same as those of white patients with the codon 17 mutation. Our study indicates that phenotypic similarities exist among patients with the same mutation, but of different racial backgrounds. The neovascularization in the right eye diminished over a two-year period in conjunction with the progression of retinal degeneration.
Adaptation, Ocular↗
cDNA cloning of a germ cell specific lamin B3 from mouse spermatocytes and analysis of its function by ectopic expression in somatic cells.
The nuclear lamina is a fundamental component involved in the assembly of the nuclear envelope and higher order chromosomal structures in eukaryotes. In mammals, it is composed of four major lamin proteins, termed lamins A, B1, B2 and C. Here we first report cDNA cloning of a new 53 kDa lamin protein from mouse spermatocytes, termed lamin B3, the expression of which appears restricted to spermatogenic cells. Its gene structure indicates that lamin B3 is generated by differential splicing and alternative polyadenylation from lamin B2. When lamin B3 is introduced into somatic cells in culture, their nuclear morphology is transformed from spherical to hook-shaped. On the basis of the results obtained, we suggest that the germ cell specific lamin B3 is involved in the reorganization of nuclear and chromosomal structures during meiotic division.
Aging↗
Isolation and characterization of a yeast gene that is homologous with a meiosis-specific cDNA from a plant.
By using as probe a meiosis-specific cDNA clone LIM15 from the monocotyledonous plant, Lilium longiflorum, a clone containing a 2.8 kb DNA fragment was isolated from a genomic library of Saccharomyces cerevisiae. Primary structure analysis revealed that the clone includes two complete open reading frames, designated ISC2 and ISC10, capable of coding for a 36.6 kDa and a 31.6 kDa polypeptide, respectively, with the former frame being interrupted by a 92 bp intron. The predicted amino acid sequence of Isc2 was 56% identical with the putative gene product of lily cDNA clone LIM15, and showed limited sequence similarity with the yeast RAD57 gene product. Transcripts of the two genes begin accumulating 2.5 h and 7.5 h after induction of meiosis, respectively, according to a Northern hybridization analysis. Since disruption of either one of these genes had a drastic effect on the ability to form spores, ISC2 and ISC10 are expected to play significant roles in the formation of reproductive cells.
Amino Acid Sequence↗
Microbial oxidation of dimethylnaphthalene isomers.
Three bacterial strains, identified as Alcaligenes sp. strain D-59 and Pseudomonas sp. strains D-87 and D-186, capable of growing on 2,6-dimethylnaphthalene (2,6-DMN) as the sole source of carbon and energy were isolated from soil samples. 2,6-Naphthalene dicarboxylic acid was formed in the culture broths of these three strains grown on 2,6-DMN. In addition, 2-hydroxymethyl-6-methylnaphthalene and 6-methylnaphthalene-2-carboxylic acid were detected in the culture broth of strain D-87. Strain D-87 grew well on 1,2-, 1,3-, 1,4-, 1,5-, 2,3-, and 2,7-DMN as the sole source of carbon and energy and accumulated 2-methylnaphthalene-3-carboxylic acid and 2,3-naphthalene dicarboxylic acid from 2,3-DMN, 4-methylnaphthalene-1-carboxylic acid from 1,4-DMN, and 7-methylnaphthalene-2-carboxylic acid from 2,7-DMN.
Alcaligenes↗