An epigenetic aberration increased in intergenic regions of cloned mice.

The causes of frequent abnormal phenotypes and low success rate in mammalian cloning are poorly understood. Although epigenetic aberration is suspected to be a cause, its connection to the phenotypes has yet to be investigated. To measure the level of reprogramming of an epigenetic mark, acetylation at lysine 9 of histone H3 (H3K9Ac), in cloned mice, we examined its conservation between two cloned mice derived from distinct cell nuclei and their natural donors by utilizing whole-genome tiling arrays and quantitative PCR.

Mitochondrial SNPs associated with Japanese centenarians, Alzheimer's patients, and Parkinson's patients.

In this paper we examined the relations between three classes of people (96 Japanese centenarians, 96 Japanese Alzheimer's disease (AD) patients and 96 Japanese Parkinson's disease (PD) patients) and their mitochondrial single nucleotide polymorphism (mtSNP) frequencies at individual mitochondrial DNA (mtDNA) positions of the entire mt-genome by using the radial basis function (RBF) networks. As a result, we got new findings of mtSNPs for representing characteristics of individual classes. These mtSNPs show distinct differences for three classes of people.

Expression analysis for inverted effects of serotonin transporter inactivation.

Inactivation of serotonin transporter (HTT) by pharmacologically in the neonate or genetically increases risk for depression in adulthood, whereas pharmacological inhibition of HTT ameliorates symptoms in depressed patients. The differing role of HTT function during early development and in adult brain plasticity in causing or reversing depression remains an unexplained paradox. To address this we profiled the gene expression of adult Htt knockout (Htt KO) mice and HTT inhibitor-treated mice.

Cytostatic evaluations of nucleoside analogs related to unnatural base pairs for a genetic expansion system.

The introduction of an unnatural base pair into DNA enables the expansion of genetic information. To apply unnatural base pairs to in vivo systems, we evaluated the cytostatic toxicity of several nucleoside analogs by an MTT assay. Several nucleoside analogs based on two types of unnatural base pairs were tested.

The RIKEN mouse transcriptome: lessons learned and implications for the regulation of immune reactions.

Notably, the technology and analysis methods of the RIKEN mouse full-length cDNA project have contributed a lot to the capture of the transcriptional output of the mouse genome and the description of its combinatorial nature. However, one corollary of this large scale transcript resource is the dichotomy of vast and missing information. As such, the transcriptional and translational output of yet unknown size following non-canonical principles remains to be established and interpreted.

Mammalian RNA polymerase II core promoters: insights from genome-wide studies.

The identification and characterization of mammalian core promoters and transcription start sites is a prerequisite to understanding how RNA polymerase II transcription is controlled. New experimental technologies have enabled genome-wide discovery and characterization of core promoters, revealing that most mammalian genes do not conform to the simple model in which a TATA box directs transcription from a single defined nucleotide position. In fact, most genes have multiple promoters, within which there are multiple start sites, and alternative promoter usage generates diversity and complexity in the mammalian transcriptome and proteome.

Rapid SNP diagnostics using asymmetric isothermal amplification and a new mismatch-suppression technology.

We developed a rapid single nucleotide polymorphism (SNP) detection system named smart amplification process version 2 (SMAP 2). Because DNA amplification only occurred with a perfect primer match, amplification alone was sufficient to identify the target allele. To achieve the requisite fidelity to support this claim, we used two new and complementary approaches to suppress exponential background DNA amplification that resulted from mispriming events.

Selecting effective siRNA target sequences for mammalian genes.

Short interfering RNA (siRNA) has been widely used for studying gene functions in mammalian cells but varies markedly in its gene-silencing efficacy in mammalian genes. The recently reported guidelines for selecting effective siRNA target sequences are not always useful for selecting highly effective siRNA sequences for many other mammalian genes because there are only a few consistencies among them. Hypothesizing that the positional nucleotide occurrence trends play an important role in effective gene-silencing, we examined 361 effective siRNA sequences from 227 different mammalian cDNAs in the literature and found got several nucleotide features different from the ones used in the previous guidelines.

Discrimination of non-protein-coding transcripts from protein-coding mRNA.

Several recent studies indicate that mammals and other organisms produce large numbers of RNA transcripts that do not correspond to known genes. It has been suggested that these transcripts do not encode proteins, but may instead function as RNAs. However, discrimination of coding and non-coding transcripts is not straightforward, and different laboratories have used different methods, whose ability to perform this discrimination is unclear.

A RecA-mediated exon profiling method.

We have developed a RecA-mediated simple, rapid and scalable method for identifying novel alternatively spliced full-length cDNA candidates. This method is based on the principle that RecA proteins allow to carry radioisotope-labeled probe DNAs to their homologous sequences, resulting in forming triplexes. The resulting complex is easily detected by mobility difference on electrophoresis.

Protein-protein interactions in the mammalian brain.

Recent genome-wide high-throughput (HTS) analyses of protein-protein interactions (PPIs) provide molecular-based information to uncover functions of cells and tissues, such as those of the mammalian brain. However, the HTS PPI data contain much false-negatives and false-positives, which should be primarily addressed in experiments. Integrating PPI data sets with other genome-wide data, such as expression profiles and phenotype data sets, provides novel biological insights.

Histone H3 acetylated at lysine 9 in promoter is associated with low nucleosome density in the vicinity of transcription start site in human cell.

Nucleosome depletion in the promoters has been indicated in yeasts, suggesting that nucleosome depletion in promoter might be a fundamental feature of eukaryotic transcriptional regulation. We compared the relationship between histone H3 acetylation at lysine 9 (K9) in promoter, gene expression level, and nucleosome density in the vicinity of the transcription start site (TSS), in HepG2 cells (human hepatocellular liver carcinoma cells). We found that the density of nucleosome is relatively low in the close vicinity of TSS flanked by H3 K9 significantly acetylated promoter, compared with that for genes without marked H3 K9 acetylation in promoter, regardless of their transcriptional activation status.

Human genome research enters a new phase.

A report on HGM2005, the tenth annual Human Genome Meeting, Kyoto, Japan, 18-21 April 2005.

Expression analysis of genes responsible for serotonin signaling in the brain.

To thoroughly understand the function and regulation of neurotransmitter systems in the brain, as well as the underlying disease mechanisms, it is important to comprehensively analyze the expression patterns of genes participating in such systems. Using functional annotated cDNA clones (FANTOM), we examined the gene expression patterns of the serotonin neurotransmitter system, which is involved in psychiatric diseases such as depression. We chose 24 gene products and visualized their endogenous localizations using in situ hybridization (ISH).

Development of a spot reliability evaluation score for DNA microarrays.

We developed a reliability index named SRED (Spot Reliability Evaluation Score for DNA microarrays) that represents the probability that the calibrated gene expression level from a DNA microarray would be less than a factor of 2 different from that of quantitative real-time polymerase chain reaction assays whose dynamic quantification range is treated statistically to be similar to that of the DNA microarray. To define the SRED score, two parameters, the reproducibility of measurement value and the relative expression value were selected from nine candidate parameters. The SRED score supplies the probability that the expression level in each spot of a microarray is less than a certain-fold different compared to other expression profiling data, such as QRT-PCR.

A novel replication-independent histone H2a gene in mouse.

Background: An uncharacterized histone H2a-coding transcript (E130307C13) has been cloned from a mouse full-length cDNA library. This transcript is encoded on chromosome 6, approximately 4 kb upstream of a histone H4 gene, Hist4h4. The proteins encoded by this transcript and the human H2afj mRNA isoform-2 have the highest amino acid similarity.

Textmining in support of knowledge discovery for vaccine development.

Complete genome data of infectious microorganisms permit systematic computational sequence-based predictions and experimental testing of candidate vaccine epitopes. Both, predictions and the interpretation of experiments rely on existing information in the literature which is mostly manually extracted and curated. The growing amount of data and literature information has created a major bottleneck for the interpretation of results and maintenance of curated databases.

Genome-wide analysis of alternative pre-mRNA splicing in Arabidopsis thaliana based on full-length cDNA sequences.

We mapped RIKEN Arabidopsis full-length (RAFL) cDNAs to the Arabidopsis thaliana genome to search for alternative splicing events. We used 278,734 full-length and 3'/5' terminal reads of the sequences of 220,214 RAFL cDNA clones for the analysis. Eighty-nine percent of the cDNA sequences could be mapped to the genome and were clustered in 17,130 transcription units (TUs).

A genome-wide and nonredundant mouse transcription factor database.

Here we describe the development of a genome-wide and nonredundant mouse transcription factor database and its viewer (http://genome.gsc.riken.

Identification of region-specific transcription factor genes in the adult mouse brain by medium-scale real-time RT-PCR.

We established a medium-scale real-time RT-PCR system focusing on transcription factors and applied it to their expression profiles in the adult mouse 11 brain regions (http://genome.gsc.riken.

From masking repeats to identifying functional repeats in the mouse transcriptome.

The back-to-back release of the mouse genome and the functionally annotated RIKEN mouse full-length cDNA collection was an important milestone in mammalian genomics. Yet much of the data remain to be explored in terms of biological effects and mechanisms. For example, interspersed repeats account for 39 per cent of the mouse genome sequence and 11 per cent of representative transcripts.

An effective method for selecting siRNA target sequences in mammalian cells.

RNA interference is a gene-silencing phenomenon triggered by dsRNA (double-stranded RNA) and has been widely used for studying gene functions. The short interfering RNA (siRNA) responsible for RNA interference, however, varies markedly in its gene-silencing efficacy. Because this efficacy depends on the selected target sequences, we developed an effective selection method based on the gene degradation measure (priority score) defined by positional features of individual nucleotides.

From immunogenetics to immunomics: functional prospecting of genes and transcripts.

Human and mouse genome and transcriptome projects have expanded the field of 'immunogenetics' beyond the traditional study of the genetics and evolution of MHC, TCR and Ig loci into the new interdisciplinary area of 'immunomics'. Immunomics is the study of the molecular functions associated with all immune-related coding and non-coding mRNA transcripts. To unravel the function, regulation and diversity of the immunome requires that we identify and correctly categorize all immune-related transcripts.

FREP: a database of functional repeats in mouse cDNAs.

The FREP database (http://facts.gsc.riken.