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Biomedical subjects

M C Yoshida

Publications and source records attributed to M C Yoshida.

At least 37 records · Page 2Linked to original sources
PubMed1998

Genetic variation and population structure of the Japanese sika deer (Cervus nippon) in Hokkaido Island, based on mitochondrial D-loop sequences.

Mitochondrial DNA (mtDNA) D-loop region sequences (602 bp) from 141 samples of the sika deer Cervus nippon collected from Hokkaido Island of Japan were investigated to elucidate population genetic structure. All animals possessed seven repeat units (38 or 39 bp each) in the sequences. Comparison of the 602-bp sequences showed four sites of transitional mutations (A<-->G or C<-->T). Based on combination of the substitutions, six D-loop haplotypes (a-f types) were identified in the Hokkaido population, suggesting the occurrence of at least six maternal lineages. Distribution maps of the haplotypes constructed using the Geographic Information System showed that the distribution of the major three types differed from haplotype to haplotype. In particular, distribution of the major three types (a-, b-, and c-types) almost overlapped with three main areas of coniferous forests in Hokkaido. These results suggest that expansion of the sika deer population could have occurred through the habitat of coniferous forests after the historical bottleneck in Hokkaido.

Animals↗
PubMed1998

Sexing of carcass remains of the Sika deer (Cervus nippon) using PCR amplification of the Sry gene.

In order to determine the sex of carcass remains of the Sika deer (Cervus nippon), we improved a polymerase chain reaction (PCR) technique for amplification of the Sika deer Sry, a male-specific DNA region on the mammalian Y chromosome. From the nucleotide sequence of the Sry region obtained here, PCR primers, MT1 and MT2, capable of amplifying a shorter Sry region were newly designed, and a microsatellite locus was used as a positive control. Using these primers, 96 of 109 sex-unknown fawns (88%, 96/109) were successfully sexed (46 males and 50 females) regardless of the conditions of carcasses found in the field. The results and the methodology could greatly contribute to the study of the mortality pattern of the Sika deer population.

Animals↗
PubMed1997

cDNA cloning, genomic organization, and chromosomal localization of the mouse LIM motif-containing kinase gene, Limk2.

LIM-kinases, including LIMK1 and LIMK2, are unique LIM-family proteins with two tandem LIM motifs at the N-terminal and a serine/threonine kinase domain at the C-terminal. In this study, we cloned two types of mouse Limk2 cDNA; one is an intact form (Limk2a) and the other has only one complete LIM domain (Limk2b). Northern blot analysis showed Limk2a mRNA was ubiquitously present in various adult tissues, while Limbk2b was predominantly expressed in brain. We also identified genomic organization of the Limk2 gene; it is similar to that of the related gene Limk1. The transcription unit contains 16 exons plus two alternative exons, thus, variation in the initiator exon usage gives rise to alternative transcripts of Limk2. Fluorescent in situ hybridization analysis showed the Limk2 gene were mapped to mouse chromosome 1D. These findings provide some important clues to the in vivo functions of LIM kinases.

Amino Acid Sequence↗
PubMed1997

Human TNF receptor-associated factor 5 (TRAF5): cDNA cloning, expression and assignment of the TRAF5 gene to chromosome 1q32.

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are signal transducers for members of the TNF receptor superfamily. We previously identified murine TRAF5 (mTRAF5) and showed that it specifically interacts with the lymphotoxin-beta receptor (LT-beta R) and activates the transcription factor NF-kappa B. Here we have cloned the human TRAF5 homologue (hTRAF5) by cross hybridization with mTRAF5 cDNA. hTRAF5 cDNA is composed of 2894 nucleotides with a 557-amino-acid open reading frame that exhibits 77.5 and 80% identity to mTRAF5 at the nucleotide and amino acid levels, respectively. Northern blot analysis revealed that hTRAF5 mRNA is expressed in all visceral organs. Western blotting revealed that hTRAF5 protein was abundantly expressed in the human follicular dentritic cell line, FDC-1, and to a much lesser degree in several tumor cell lines. Interspecific backcross mapping revealed that Traf5 is located in the distal region of mouse chromosome 1, which shares a region of homology with human chromosome 1q. Fluorescence in situ hybridization confirmed regional localization to human chromosome 1q32.

Amino Acid Sequence↗
PubMed1997

Uniparental chromosome elimination in the early embryogenesis of the inviable salmonid hybrids between masu salmon female and rainbow trout male.

Chromosome elimination through chromosome loss and partial deletion is known to be one of the causes of embryonic inviability in some salmonid interspecific hybrids. Using fluorescence in situ hybridization and related techniques, including whole chromosome painting and comparative genomic hybridization, parental origin of eliminated chromosomes was identified in the inviable hybrids between masu salmon (Ms, Oncorhynchus masou) female and rainbow trout (Rb, O. mykiss) male at the early embryonic stage prior to death. In these hybrids, the haploid Rb chromosome number decreased to nearly half, whereas the Ms chromosomes were retained as one or occasionally two full haploid complements. The Rb chromosomes were also involved in the frequently observed fragments and micronuclei. Whereas the occurrence of fragments was constant throughout the observed period, chromosome loss occurred mainly from just after fertilization to the blastulae stage. In tissue sections and cell spreads of late blastula, some Rb chromosomes were trapped in the midzone from ana- to telophase, resulting in micronuclei at the subsequent interphase. Micronuclei and mitotic abnormalities were also observed in the androgenetic haploid hybrids. However, such abnormalities were seldom or never observed in the viable reciprocal hybrids. The present findings suggest that the paternal Rb chromosomes in the inviable hybrids are preferentially eliminated through mitotic abnormalities during early embryogenesis, owing to a possible incompatibility between the maternal Ms cytoplasm and paternal Rb genome.

Animals↗
PubMed1997

Sex-related spatial kin structure in a spring population of grey-sided voles Clethrionomys rufocanus as revealed by mitochondrial and microsatellite DNA analyses.

Polymerase chain reaction-directed mitochondria (mt) and microsatellite DNA analyses were performed to examine the kin structure in a spring population of grey-sided voles Clethrionomys rufocanus in Hokkaido, Japan. The spatial distribution of 81 voles in a trapping grid (about 1 ha) was estimated by using the catch-mark-release method. DNA samples were extracted from the toes clipped for individual identification. Maternal lineages of voles were unequivocally determined by the mtDNA haplotypes, as identified by nucleotide sequencing of the control region. Relatedness between individuals was estimated based on the genotype and allele frequencies at several microsatellite loci. Although the distribution of voles was uniform within the grid, neighbouring females were frequently from the same maternal lineage. Relatedness values between females correlated negatively with geographical distances. Combination of the two molecular markers revealed four clusters of closely related, matrilineal females in the population, whereas no such cluster was apparent in males. The present study first demonstrated a sex-related spatial kin structure in a natural population of the grey-sided vole.

Animals↗
PubMed1996

Characterization of a human glycoprotein with a potential role in sperm-egg fusion: cDNA cloning, immunohistochemical localization, and chromosomal assignment of the gene (AEGL1).

Acidic epididymal glycoprotein (AEG), thus far identified only in rodents, is one of the sperm surface proteins involved in the fusion of the sperm and egg plasma membranes. In the present study, we describe the isolation and characterization of cDNA encoding a human glycoprotein related to AEG. Although this protein, designated ARP (AEG-related protein), is not the ortholog of rodent AEG, it resembles AEG in that it is an epididymal secretory glycoprotein that binds to the postacrosomal region of the sperm head. The fact that no AEG mRNA can be detected in the human epididymis suggests that ARP might be the functional counterpart of rodent AEG. The gene encoding ARP (AEGL1) was mapped by fluorescence in situ hybridization to 6p21.1-p21.2. This result indicates that AEGL1 and the mouse gene for AEG are located in the chromosomal segments with conserved syntenies.

Acrosome↗
PubMed1996

Assignment of the gene encoding type 1 gamma protein phosphatase catalytic subunit (PPP1CC) on human, rat, and mouse chromosomes.

Using fluorescent in situ hybridization (FISH) method, a gene encoding the catalytic subunit of protein phosphatase type 1 gamma (PPP1CC) was mapped to human 12q24.1-q24.2, rat 7 q22, and mouse 10C. These results indicate that the PPP1CC is a member of conserved synteny group between rat chromosome 7, mouse chromosome 10 and human chromosome 12. These data and mapping data about other members of PP1 family show that in spite of the high identity of PP1 isoforms, each isoform is encoded by different genes which located on different chromosomes in human, rat, and mouse.

Animals↗
PubMed1996

Phylogenetic relationships among Japanese species of the family Sciuridae (Mammalia, Rodentia), inferred from nucleotide sequences of mitochondrial 12S ribosomal RNA genes.

In order to investigate phylogenetic relationships of the family Sciuridae living in Japan, we sequenced partial regions (379 bases) of mitochondrial 12S rRNA genes in six species of Japanese and other Asian squirrels. Phylogenetic trees constructed by sequence data indicated that two genera of flying squirrels (Petaurista and Pteromys) were clustered in a group distinct from non-flying squirrels, suggesting a possible monophyletic relationships of these flying squirrels. The evolutionary distance between the Japanese squirrel (Sciurus lis) from Honshu island and the Eurasian red squirrel (Sciurus vulgaris) from Hokkaido island was comparable to intraspecific distances of the remaining species examined.

Animals↗
PubMed1995

Cloning, sequence analysis, and chromosomal assignment of the mouse Apex gene.

APEX nuclease (Apex gene product) is a mammalian multifunctional DNA repair enzyme possibly involved in the repair of apurinic/apyrimidinic (AP) sites and single-strand DNA breaks with 3' termini blocked by nucleotide fragments and also in transcriptional regulation via redox activation of the AP-1 transcription factors. We cloned a 15-kb DNA fragment containing the Apex gene from a mouse leukocyte genomic library and determined a 4-kb stretch of its nucleotide sequence, including the complete sequence of the mouse Apex gene. The gene consists of 5 exons and 4 introns spanning 2.21 kb, and the boundaries between exons and introns follow the GT/AG rule. Two major and one minor transcription initiation sites were assigned to positions +1 and +24 and position +14, respectively, by a combination of ribonuclease protection, primer extension, and 5' RACE analyses. Position +1 is located 312 nucleotides upstream from the ATG initiation codon. The translation initiation and termination sites are located in exon II and exon V, respectively. The sequenced 5' flanking region (1.32 kb) lacks a typical TATA box, but contains a CAAT box and putative binding sites for several transcription factors, such as ATF, NF-IL6, Sp1, and AP2. The 0.8-kb region from position -410 (5' flanking region) to position +386 (intron II) contains a CpG island. The Apex gene locus was mapped to mouse chromosome 14C2-D1 using in situ hybridization.

Animals↗