Asato Kuroiwa

Asato Kuroiwa
Hokkaido University | Hokudai · Faculty of Science

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83
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Publications

Publications (83)
Article
Full-text available
Birds in the clade Palaeognathae, excluding Tinamiformes, have morphologically conserved karyotypes and less differentiated ZW sex chromosomes compared with those of other birds. In particular, the sex chromosomes of the ostrich and emu have exceptionally large recombining pseudoautosomal regions (PARs), while non-PARs are classified into two strat...
Article
We previously reported that egg activation in Japanese quail is driven by two distinct types of intracellular Ca²⁺ ([Ca²⁺]i): transient elevations in [Ca²⁺]i induced by phospholipase Czeta 1 (PLCZ1) and long-lasting spiral-like Ca²⁺ oscillations by citrate synthase (CS) and aconitate hydratase 2 (ACO2). Although the blockade of inositol 1,4,5-trisp...
Article
Embryogenesis proceeds by a highly regulated series of events. In animals, maternal factors that accumulate in the egg cytoplasm control cell cycle progression at the initial stage of cleavage. However, cell cycle regulation is switched to a system governed by the activated nuclear genome at a specific stage of development, referred to as maternal-...
Article
Full-text available
Research on avian sex determination has focused on the chicken. In this study, we established the utility of another widely used animal model, the Japanese quail (Coturnix japonica), for clarifying the molecular mechanisms underlying gonadal sex differentiation. In particular, we performed comprehensive gene expression profiling of embryonic gonads...
Article
The Tokunoshima spiny rat Tokudaia tokunoshimensis is an endemic species in Tokunoshima Island, southern Japan, and an endangered species. However, records and data on the distribution of this species are extremely limited. The objective of this study was to determine the current status of the Tokunoshima spiny rat, to assist in the establishment o...
Article
Full-text available
Two species of spiny rats, Tokudaia osimensis and Tokudaia tokunoshimensis, show an X0/X0 sex chromosome constitution due to the lack of a Y chromosome. The Sry gene has been completely lost from the genome of these species. We hypothesized that Sox3, which is thought to be originally a homologue of Sry, could function in sex determination in these...
Article
Background: Although Tokudaia muenninki has multiple extra copies of the Sry gene on the Y chromosome, loss of function of these sequences is indicated. To examine the Sry gene function for sex-determining in T. muenninki, we screened a BAC library and identified a clone (SRY26) containing complete SRY coding and promoter sequences. Results: SRY...
Article
DEAD-box helicase 4 (DDX4; also known as vasa) is essential for the proper formation and maintenance of germ cells. Although DDX4 is conserved in a variety of vertebrates and invertebrates, its roles differ between species. This study investigated the function of DDX4 in chicken embryos by knocking down its expression using retroviral vectors that...
Chapter
The sex of birds is genetically determined. Females have a heterogametic sex chromosome constitution (ZW), whereas males are homogametic (ZZ). Genes carried on these sex chromosomes control gonadal differentiation and development during embryogenesis. There are two hypotheses for the mechanisms of sex determination. One proposes that the dosage of...
Article
Full-text available
X chromosome inactivation (XCI) is an essential mechanism to compensate gene dosage in mammals. Here, we show that XCI has evolved differently in two species of the genus Tokudaia. The Amami spiny rat, Tokudaia osimensis, has a single X chromosome in males and females (XO/XO). By contrast, the Okinawa spiny rat, Tokudaia muenninki, has XX/XY sex ch...
Article
Full-text available
In initial studies of the eutherian small Indian mongoose (Herpestes auropunctatus), the Y chromosome could not be identified in somatic cells. The male chromosome number is uniquely odd, 2n = 35, whereas that of females is 2n = 36. Previous reports indicated that this unique karyotype resulted from a translocation of the ancestral Y chromosome to...
Article
Full-text available
Two species of the genus Tokudaia lack the Y chromosome and SRY, but several Y-linked genes have been rescued by translocation or transposition to other chromosomes. Tokudaia muenninki is the only species in the genus that maintains the Y owing to sex chromosome-autosome fusions. According to previous studies, many SRY pseudocopies and other Y-link...
Article
Full-text available
Sex chromosomes of extant eutherian species are too ancient to reveal the process that initiated sex-chromosome differentiation. By contrast, the neo-sex chromosomes generated by sex-autosome fusions of recent origin in Tokudaia muenninki are expected to be evolutionarily ‘young’, and therefore provide a good model in which to elucidate the early p...
Article
Full-text available
SRY (sex-determining region Y) is widely conserved in eutherian mammals as a sex-determining gene located on the Y chromosome. SRY proteins bind to the testis-specific enhancer of SOX9 (TES) with SF1 to upregulate SOX9 expression in undifferentiated gonads of XY embryos of humans and mice. The core region within TES, named TESCO, is an important en...
Article
Cichlid fishes in the African Great Lakes are known as a spectacular example of adaptive radiation in vertebrates. Four linkage maps have been constructed to identify the genes responsible for adaptation and speciation, and the genetic linkages of those genes are assumed to play an important role during adaptive evolution. However, it is difficult...
Article
Full-text available
The genus Tokudaia comprises three species, two of which have lost their Y chromosome and have an XO/XO sex chromosome constitution. Although Tokudaia muenninki (Okinawa spiny rat) retains the Y chromosome, both sex chromosomes are unusually large. We conducted a molecular cytogenetic analysis to characterize the sex chromosomes of T. muenninki. Us...
Data
Painting FISH using the B1 probe in the metaphase spread of wild-caught individuals of 10 species of Lake Victoria cichlids. (A) Haplochromis plagiodon, (B) Pundamilia pundamilia, (C) Haplochromis pyrrhocephalus, (D) Neochromis greenwoodi, (E) Haplochromis tanaos, (F) Lithochromis rufus, (G) Haplochromis sp. “purple yellow”, (H) Neochromis rufocaud...
Data
Meiotic chromosomes in the males of the pedigree of L. rubripinnis from the Matumbi island population. Meiotic chromosomes of the three F2 males of L. rubripinnis are indicated in intact (A, C and E) and annotated images (B, D and F). Each chromosome is surrounded by line (B, D and F). The observed haploid number is indicated (n). SC, sperm cells....
Data
ihhb region and primer locations. Red box indicates exon 2 of ihhb. The sites that differ between the sequences of ihhb paralogs and the ihhb ortholog are shown as “T/C” and “C/T” (paralog/ortholog). The primers are shown in Table S5. (TIF)
Data
Phylogenetic tree of the ihhb region sequences (2387 bp) of African cichlids. Tree is constructed by neighbor-joining (NJ), minimum-evolution (ME), and maximum-parsimony (MP) methods. The tree was constructed using the ihhb ortholog region of cichlids from three lakes and the ihhb paralog region in the B-BAC sequence. Perissodus microlepis is used...
Data
FISH analysis using DNA probes that include the sequence of DNA markers for LG3 in the metaphase spreads of Lake Victoria cichlids. GM385 (A) and dmrt4 (B) are DNA markers of LG3 in Tilapia. The images were obtained by merging the DAPI-stained patterns (blue) and the signals from the FISH probe (green). Arrows indicate chromosome 1. The distinct si...
Data
A model for how B chromosomes gained their sex determination-related function during evolution. (A) The B chromosome emerged from a sex chromosome (chromosome 1). A sex determination-related gene was also duplicated to appear in the B chromosome. (B) The expression of the gene was suppressed in the heterochromatic state (as indicated by wavy lines)...
Data
Differences in the size distribution of B chromosomes among populations of Lake Victoria cichlids. (A) Size variation of the B chromosomes painted by the B1 probe (above) and stained with DAPI (bottom). The size of the B chromosomes was calculated by comparison with the mean size of A chromosomes (indicated as 1.00). The images of B chromosomes wer...
Data
Distribution of the B chromosome in the L. rubripinnis pedigree. (DOC)
Data
The size of B chromosomes in wild-caught Lake Victoria cichlid individuals. (DOC)
Data
Known repetitive sequences in the B chromosomes of H. chilotes. (DOC)
Data
Protein-coding genes in the B chromosomes. (DOC)
Data
FISH analysis using the Bseq1 probe in the metaphase spread of L. rubripinis. Arrowheads indicate B chromosomes. The images were obtained by merging the DAPI-stained patterns (blue) and the signals from the FISH probe (green). Scale bar, 5 µm. (TIF)
Article
Full-text available
The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish,...
Article
Tokudaia osimensis (the Amami spiny rat) and Tokudaia tokunoshimensis (the Tokunoshima spiny rat) have a sex chromosome composition of XO/XO, no Y chromosome. The mammalian sex-determining gene, SRY, is also absent in these species, which indicates that these spiny rats exhibit a novel sex-determining mechanism that is independent of SRY. To identi...
Data
Identities of nucleotide sequence between the Ryukyu spiny rat and mouse
Data
Alignment of 24 different sequences containing the full-length ORF of SRY with partial 5' UTR and 3' UTR of T. muenninki. Identical residues are indicated by dots (.). The start codons and the stop codons are colored dark gray and light gray, respectively. The HMG-box is underlined. The sites of insertion/deletion are indicated by
Article
The Okinawa spiny rat, Tokudaia muenninki, is the only species with a Y chromosome in the genus Tokudaia. Its phylogenic relationship with two XO/XO species, Tokudaia osimensis and Tokudaia tokunoshimensis, lacking a Y chromosome and the mammalian sex-determining gene SRY, is unknown. Furthermore, there has been little cytogenetic analysis of the s...
Article
The Ryukyu spiny rat, Tokudaia osimensis, has an XO/XO sex chromosome constitution, lacking a Y chromosome and the mammalian sex-determining gene SRY. To investigate the Y-loss event, we traced three proto-Y-linked genes, RBMY1A1, EIF2S3Y, and KDM5D, in the genome. The original Y-linked RBMY1A1 was lost as well as SRY, and the remaining RBMY1A1 was...
Article
Two species of Ryukyu spiny rat, Tokudaia osimensis and Tokudaia tokunoshimensis, have an XO/XO sex chromosome constitution with no cytogenetically visible Y chromosome in both sexes. The single X chromosomes of T. osimensis and T. tokunoshimensis are submetacentric and subtelocentric, respectively. It was therefore suggested that a pericentric inv...
Article
Full-text available
Ryukyu spiny rats (genus Tokudaia) are indigenous species that are confined to three islands of the Nansei Shoto archipelago, Amami-Oshima, Tokunoshima and Okinawa-jima, Japan. Tokudaia tokunoshimensis from Tokunoshima Island and Tokudaia osimensis from Amami-Oshima Island are closely related taxonomically, although their karyotypes are quite diffe...
Article
Full-text available
An interspecific hybrid medaka (rice fish) between Oryzias latipes and O. hubbsi is embryonically lethal. To gain an insight into the cellular and molecular mechanisms that cause the abnormalities occurring in the hybrid medaka, we investigated the behavior of chromosomes and the expression patterns of proteins responsible for the chromosome behavi...
Article
The Ryukyu spiny rats (genus Tokudaia) inhabit only three islands in the Nansei Shoto archipelago in Japan, and have the variations of karyotype among the islands. The chromosome number of T. osimensis in Amami-Oshima Island is 2n = 25, and T. tokunoshimensis in Tokunoshima Island is 2n = 45, and the two species have X0 sex chromosome constitution...
Article
The murine nuclear protein Np95 has been shown to underlie resistance to ionizing radiation and other DNA insults or replication arrests in embryonic stem (ES) cells. Using the databases for expressed sequenced tags and a two-step PCR procedure, we isolated human NP95, the full-length human homologue of the murine Np95 cDNA, which consists of 4,327...
Article
The observation that LINE-1 transposable elements are enriched on the X in comparison to the autosomes led to the hypothesis that LINE-1s play a role in X chromosome inactivation. If this hypothesis is correct, loss of LINE-1 activity would be expected to result in species extinction or in an alternate pathway of dosage compensation. One such alter...
Article
The protooncogene product Myc associates with many proteins. The isolation of the mouse MM-1; c-Myc binding protein (Myc-Modulator 1) cDNA is described. The cDNA contains a 462 bp open reading frame that encodes a polypeptide of 154 amino acid residues. The deduced amino acid sequence indicates that mouse MM-1 has a 99% identity with the sequence o...
Article
We report the isolation of human pleckstrin 2 cDNA. The cDNA contains a 1059 bp open reading frame encoding a polypeptide of 353 amino acid residues. The deduced amino acid sequence indicates that pleckstrin 2 contains two pleckstrin homology domains and a DEP (dishvelled, egl-10, and pleckstrin) domain and had a 95% identity with the sequence of m...
Article
Full-text available
The karyotypes of birds, turtles and snakes are characterized by two distinct chromosomal components, macrochromosomes and microchromosomes. This close karyological relationship between birds and reptiles has long been a topic of speculation among cytogeneticists and evolutionary biologists; however, there is scarcely any evidence for orthology at...
Article
Full-text available
Immune responses are regulated by opposing positive and negative signals triggered by the interaction of activating and inhibitory cell surface receptors with their ligands. Here, we describe novel paired activating and inhibitory immunoglobulin-like receptors, designated myeloid-associated immunoglobulin-like receptor (MAIR) I and MAIR-II, whose e...
Article
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Translational control of specific mRNAs by cytoplasmic polyadenylation has fundamental roles in gametogenesis. The cytoplasmic polyadenylation element binding (CPEB) protein regulates cytoplasmic polyadenylation of mRNAs as a trans factor in oogenesis and spermatogenesis. The CPEB protein contains two RNA recognition motifs and a Zn-finger structur...
Article
Full-text available
Heparan sulphate 6- O -sulphotransferase (HS6ST) catalyses the transfer of sulphate from adenosine 3'-phosphate, 5'-phosphosulphate to the 6th position of the N -sulphoglucosamine residue in HS. We previously described the occurrence of three isoforms of mouse HS6ST, mHS6ST-1, -2, and -3 [Habuchi, Tanaka, Habuchi, Yoshida, Suzuki, Ban and Kimata (2...
Article
We have reported on Spred-1 and Spred-2, which inhibit MAP kinase activation by interacting with c-kit and ras/raf. Here, we report the cloning of a third member in this family, Spred-3. Spred-3 is expressed exclusively in the brain and its gene locates in chromosome 19q13.13 in human. Like Spred-1 and -2, Spred-3 contains an EVH1 domain in the N-t...
Article
Full-text available
Comparative chromosome painting was applied to the Indian spiny mouse (Mus platythrix) with mouse (M. musculus) chromosome-specific probes for understanding the process of chromosome rearrangements between the two species. The chromosome locations of the 5S and 18S-28S ribosomal RNA genes and the order of the 119 and Tcp-1 genes in the In(17)2 regi...
Article
Production of transgenic animals is an important technique for studying various biological processes. However, whether the integration of a particular transgene occurs randomly in the mouse genome has not been determined. Analysis by fluorescence in situ hybridization of the integration sites of the 142 EGFP (a mutant of green fluorescent protein)...
Article
We have cloned a new mouse ATP-binding cassette (ABC) transporter, Abcg4, from a complementary DNA (cDNA) library of mouse brain. The cloned Abcg4 cDNA encodes a protein consisting of 646 amino acids and including one ATP-binding cassette and six transmembrane domains. The Abcg4 protein exhibits high identity (96%) with human ABCG4 in terms of the...
Article
Fertilin is reported to be a heterodimeric protein composed of A Disintegrin And Metalloprotease 1 (ADAM1, fertilin alpha) and ADAM2 (fertilin beta) located on the sperm surface. In the process of clarifying the molecular basis of mouse ADAM1, we have identified two intron-less mouse genes encoding different isoforms of ADAM1, termed ADAM1a and ADA...
Article
Full-text available
In birds, females are heterogametic (ZW), while males are homogametic (ZZ). It has been proposed that there is no dosage compensation for the expression of Z-linked genes in birds. In order to examine if the genes are inactivated on one of the two Z chromosomes, we analyzed the allelic expression of the B4GALT1 and CHD-Z genes on Z chromosomes in m...
Article
Chromosome locations of the eight SOX family genes, SOX1, SOX2, SOX3, SOX5, SOX9, SOX10, SOX14 and SOX21, were determined in the chicken by fluorescence in situ hybridization. The SOX1 and SOX21 genes were localized to chicken chromosome 1q3.1-->q3.2, SOX5 to chromosome 1p1.6-->p1.4, SOX10 to chromosome 1p1.6, and SOX3 to chromosome 4p1.2-->p1.1. T...
Article
Five members of the RecQ helicase family, RECQL, WRN, BLM, RTS and RECQL5, have been found in human and three of them (WRN, BLM and RTS) were disclosed to be the genes responsible for Werner, Bloom and Rothmund–Thomson syndromes, respectively. RECQL5 (RecQ helicase protein-like 5) was isolated as the fifth member of the family in humans through a s...
Article
Genes belonging to the piwi family are required for stem cell self-renewal in diverse organisms. We cloned mouse homologues of piwi by RT-PCR using degenerative primers. The deduced amino acid sequences of mouse homologues MIWI and MILI showed that each contains a well-conserved C-terminal PIWI domain and that each shares significant homology with...
Article
We constructed comparative cytogenetic maps of the Chinese hamster to mouse, rat and human by fluorescence in-situ hybridization using 36 cDNA clones of mouse, rat, Syrian hamster, Chinese hamster and human functional genes. In this study, 30 out of the 36 genes were newly mapped to Chinese hamster chromosomes. The chromosomal homology of the Chine...
Article
Full-text available
The presence of mouse embryonic stem (ES) cells makes the mouse a powerful model organism for reverse genetics, gene function study through mutagenesis of specific genes. In contrast, forward genetics, identification of mutated genes responsible for specific phenotypes, has an advantage to uncover novel pathways and unknown genes because no a prior...
Article
Full-text available
The direct R-banding fluorescence in situ hybridization (FISH) method was used to map 18S-28S ribosomal RNA genes and 10 human cDNA clones on the chromosomes of the musk shrew (Suncus murinus). The chromosomal locations of 18S-28S ribosomal RNA genes were examined in the five laboratory lines and wild animals captured in the Philippines and Vietnam...
Article
We determined chromosome locations of four plexin A subfamily genes, Plxna1, Plxna2, Plxna3 and Plxna4, in four rodent species, mouse, rat, Syrian hamster and Chinese hamster, by fluorescence in situ hybridization. Plxna1, Plxna2, Plxna3 and Plxna4 were localized to Chr 6E2, 1H6, XB-C1 and 6B1 in mouse, Chr 4q34.1, 13q26-->q27, Xq37.1-->q37.2 and 4...
Article
Forty-one cDNA clones of human functional genes were newly mapped to chromosomes of the musk shrew (Suncus murinus, Insectivora) by fluorescence in situ hybridization, and a comparative cytogenetic map of 51 genes, including 10 genes reported in our previous study, was constructed between human (HSA) and musk shrew (SMU) chromosomes. In this compar...
Article
Ku proteins play an important role in DNA double-strand break (DSB) repair, chromosome maintenance, and growth regulation. To understand the fundamental characteristics of Ku proteins, we examined the electrophoretic mobility and expression of hamster Ku70 and Ku80 and determined the chromosome locations of their genes. The electrophoretic mobility...
Article
By screening 26 chicken breeds and lines, DNA polymorphisms were identified in the IGF2 and MPR1 genes, of which mammalian homologues are parentally imprinted, and the GAPD gene, a housekeeping control. Using the polymorphisms as genetic markers, we found that all three genes are expressed biallelically in embryonic tissues. IGF2 and MPR1 were mapp...
Article
Three highly homologous homeobox genes (caupolican, araucan and mirror) have been identified in Drosophila. These genes belong to the novel Iroquois complex, which acts as a pre-pattern molecule in Drosophila neurogenesis. Recently several vertebrate Iroquois homologues (Irx) were isolated and found to be involved in pattern formation of various ti...
Article
Five members of the RecQ helicase family, RECQL, WRN, BLM, RECQL4 and RECQL5 have been identified in humans. WRN and BLM have been demonstrated to be the responsible genes in Werner and Bloom syndromes, respectively. RECQL4 (RecQ helicase protein-like 4) was identified as a fourth member of the human RecQ helicase family bearing the helicase domain...
Article
We constructed the comparative cytogenetic maps of X chromosomes in three rodent species, Indian spiny mouse (Mus platythrix), Syrian hamster and Chinese hamster, using 26 mouse cDNA clones. Twenty-six, 22 and 22 out of the 26 genes, which were mapped to human, mouse and rat X chromosomes in our previous study, were newly localized to X chromosomes...
Article
Chondroitin 4-sulfotransferase (C4ST) catalyzes the transfer of sulfate from 3′-phospho-adenosine 5′-phosphosulfate to position 4 of the N-acetylgalactosamine residues of chondroitin. We previously reported the cloning of C4ST cDNA from mouse brain. We here report the cloning and expression of human C4ST cDNA. The cDNA was isolated from a human fet...
Article
Unlike mammals, avian circadian rhythms are regulated by a multiple oscillatory system consisting of the retina, the pineal and the suprachiasmatic nucleus in the hypothalamus. To understand avian circadian system, we have cloned Clock and Period homologs (qClock, qPer2 and qPer3) and characterized these genes in Japanese quail. Overall, qCLOCK, qP...