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1.
Sci Rep ; 9(1): 16200, 2019 11 07.
Article in English | MEDLINE | ID: mdl-31700052

ABSTRACT

It is important to unravel how invasive species impact native ecosystems in order to control them effectively. The presence of abundant exotic prey promotes population growth of invasive predators, thereby enhancing the predation pressure on native prey (hyper-predation). Not only the exotic prey but also feeding by humans is likely to cause "hyper-predation". However, the contribution of artificial resources to this was underestimated in previous studies. Here, we combined fecal and stable isotope analyses to reveal short- and long-term food habits of free-ranging cats on Tokunoshima Island. Although 20.1% of the feral cat feces contained evidence of forest-living species, stable isotope analysis suggested that the cats were mostly dependent on artificial resources. In addition, a general linear model analysis showed that their diet was strongly correlated with landscape variables. These results indicate that the invasive free-ranging cats are aided by anthropogenic feeding, and they move from the human habituated area to natural areas with high biodiversity. These findings suggest the possibility of human feeding indirectly accelerates the effect of cat predation, and call for a further study on their demography. Cat management mainly involves trapping, but our findings show that educating local residents to stop feeding free-ranging cats and keeping pet cats indoors are also important.


Subject(s)
Endangered Species , Islands , Predatory Behavior , Animals , Cats , Diet , Feces/chemistry , Humans
2.
Mol Phylogenet Evol ; 136: 65-75, 2019 07.
Article in English | MEDLINE | ID: mdl-30951923

ABSTRACT

Hares of the genus Lepus are distributed worldwide, and introgressive hybridization is thought to be pervasive among species, leading to reticulate evolution and taxonomic confusion. Here, we performed phylogeographic analyses of the following species of hare across East Asia: L. timidus, L. mandshuricus, L. coreanus, and L. brachyurus collected from far-eastern Russia, South Korea, and Japan. Nucleotide sequences of one mitochondrial DNA and eight nuclear gene loci were examined, adding sequences of hares in China from databases. All nuclear DNA analyses supported the clear separation of three phylogroups: L. timidus, L. brachyurus, and the L. mandshuricus complex containing L. coreanus. On the other hand, massive mitochondrial introgression from two L. timidus lineages to the L. mandshuricus complex was suggested in continental East Asia. The northern population of the L. mandshuricus complex was mainly associated with introgression from the continental lineage of L. timidus, possibly since the last glacial period, whereas the southern population of the L. mandshuricus complex experienced introgression from another L. timidus lineage related to the Hokkaido population, possibly before the last glacial period. In contrast to continental hares, no evidence of introgression was found in L. brachyurus in the Japanese Archipelago, which showed the oldest divergence amongst East Asian hare lineages. Our findings suggest that glacial-interglacial climate changes in the circum-Japan Sea region promoted distribution shifts and introgressive hybridization among continental hare species, while the geographic structure of the region contributed to long-term isolation of hares on the islands, preventing inter-species gene flow.


Subject(s)
Hares/genetics , Islands , Mitochondria/genetics , Phylogeography , Animals , Base Sequence , Bayes Theorem , Cell Nucleus/genetics , DNA/genetics , DNA, Mitochondrial/genetics , Asia, Eastern , Genetic Loci , Geography , Hares/classification , Phylogeny
3.
Biol Psychol ; 142: 70-79, 2019 03.
Article in English | MEDLINE | ID: mdl-30703464

ABSTRACT

The concealed information test (CIT), a memory detection test, compares physiological responses to crime-related and crime-unrelated items. This study elucidated processes involving spontaneous eyeblinks during the CIT by manipulating participants' intention to conceal. Thirty-four participants committed mock theft. In the CIT, wherein eyeblinks are measured simultaneously with autonomic responses, the secret group concealed the crime-related item, whereas the no-secret group did not. As a result, heart rate (HR) was modulated by the intention of concealment in autonomic measures, whereas the effect of concealment on the decrease of eyeblinks was not found to be significant. In addition, the latency of the first eyeblink was longer for the crime-related item in both groups. These results imply that CIT eyeblinks mainly involve the process of selective attention for the item, and the latency of the first eyeblink reflects a delay in attentional disengagement from the item. This study also suggested that there is still room for improvement in simultaneously measuring eyeblinks and autonomic responses in the CIT.


Subject(s)
Attention/physiology , Blinking/physiology , Crime/psychology , Memory and Learning Tests , Memory/physiology , Adult , Autonomic Nervous System/physiology , Female , Heart Rate/physiology , Humans , Male , Young Adult
4.
Environ Sci Technol ; 51(8): 4632-4641, 2017 04 18.
Article in English | MEDLINE | ID: mdl-28363014

ABSTRACT

Since the Fukushima Dai-ichi Nuclear Power Plant accident, radiation effects on nonhuman biota in the contaminated areas have been a major concern. Here, we analyzed the frequencies of chromosomal aberrations (translocations and dicentrics) in the splenic lymphocytes of large Japanese field mice (Apodemus speciosus) inhabiting Fukushima Prefecture. A. speciosus chromosomes 1, 2, and 5 were flow-sorted in order to develop A. speciosus chromosome-specific painting probes, and FISH (fluorescence in situ hybridization) was performed using these painting probes to detect the translocations and dicentrics. The average frequency of the translocations and dicentrics per cell in the heavily contaminated area was significantly higher than the frequencies in the case of the noncontaminated control area and the slightly and moderately contaminated areas, and this aberration frequency in individual mice tended to roughly increase with the estimated dose rates and accumulated doses. In all four sampling areas, the proportion of aberrations occurring in chromosome 2 was approximately >3 times higher than that in chromosomes 1 and 5, which suggests that A. speciosus chromosome 2 harbors a fragile site that is highly sensitive to chromosome breaks induced by cellular stress such as DNA replication. The elevated frequency of chromosomal aberrations in A. speciosus potentially resulting from the presence of a fragile site in chromosome 2 might make it challenging to observe the mild effect of chronic low-dose-rate irradiation on the induction of chromosomal aberrations in A. speciosus inhabiting the contaminated areas of Fukushima.


Subject(s)
Chromosome Aberrations , Fukushima Nuclear Accident , Murinae/genetics , Nuclear Power Plants , Animals , In Situ Hybridization, Fluorescence , Mice
5.
J Mol Evol ; 83(1-2): 12-25, 2016 08.
Article in English | MEDLINE | ID: mdl-27306379

ABSTRACT

Studies of the process of pseudogenization have widened our understanding of adaptive evolutionary change. In Rabbit, an alteration at the second extra-cellular loop of the CCR5 chemokine receptor was found to be associated with the pseudogenization of one of its prime ligands, the chemokine CCL8. This relationship has raised questions about the existence of a causal link between both events, which would imply adaptive gene loss. This hypothesis is evaluated here by tracing back the history of the genetic modifications underlying the chemokine pseudogenization. The obtained data indicate that mutations at receptor and ligand genes occurred after the lineage split of New World Leporids versus Old World Leporids and prior to the generic split of the of Old World species studied, which occurred an estimated 8-9 million years ago. More important, they revealed the emergence, before this zoographical split, of a "slippery" nucleotide motif (CCCCGGG) at the 3' region of CCL8-exon2. Such motives are liable of generating +1G or -1G frameshifts, which could, however, be overcome by "translesion" synthesis or somatic reversion. The CCL8 pseudogenization in the Old World lineage was apparently initiated by three synapomorphic point mutations at the exon2-intron2 boundary which provide at short range premature terminating codons, independently of the reading frame imposed by the slippery motif. The presence of this motif in New World Leporids might allow verifying this scenario. The importance of CCL8-CCR5 signaling in parasite-host interaction would suggest that the CCL8 knock-out in Old World populations might be related to changes in pathogenic environment.


Subject(s)
Adaptation, Biological/genetics , Chemokine CCL8/genetics , Evolution, Molecular , Animals , Chemokine CCL8/metabolism , Mutation , Phylogeny , Rabbits , Receptors, CCR5/genetics , Receptors, CCR5/metabolism , Sequence Analysis, DNA
6.
Chromosoma ; 125(4): 807-15, 2016 09.
Article in English | MEDLINE | ID: mdl-26743516

ABSTRACT

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 an autosome. However, it has been difficult to identify the chromosomes that harbor the translocated Y chromosomal segment because it is an extremely small euchromatic region. Using a Southern blot analysis, we detected four conserved Y-linked genes, SRY, EIF2S3Y, KDM5D, and ZFY, in the male genome. We cloned homologues of these genes and determined their sequences, which showed high homology to genes in two carnivore species, cat and dog. To unambiguously identify the Y-bearing autosome, we performed immunostaining of pachytene spermatocytes using antibodies against SYCP3, γH2AX, and the centromere. We observed trivalent chromosomes, and the associations between the distal ends of the chromosomes were consistent with those of Y and X1 chromosomes. The centromere of the Y chromosome was located on the ancestral Y chromosomal segment. We mapped the complementary DNA (cDNA) clones of these genes to the male chromosomes using fluorescence in situ hybridization (FISH), and the linear localization of all genes was confirmed by two-colored FISH. These Y-linked genes were localized to the proximal region of the long arm of a single telomeric chromosome, and we successfully identified the chromosome harboring the ancestral Y chromosomal segment.


Subject(s)
Genes, Y-Linked/genetics , Genetic Markers/genetics , Herpestidae/genetics , In Situ Hybridization, Fluorescence/veterinary , Karyotype , Y Chromosome/genetics , Animals , Base Sequence , Cats , Cells, Cultured , Centromere/physiology , Cloning, Molecular , Dogs , Histone Demethylases/genetics , Kruppel-Like Transcription Factors/genetics , Male , Sequence Analysis, DNA , Sex-Determining Region Y Protein/genetics , Transcription Factors/genetics , Translocation, Genetic
7.
Environ Sci Technol ; 49(16): 10074-83, 2015 Aug 18.
Article in English | MEDLINE | ID: mdl-26217955

ABSTRACT

Following the Fukushima Dai-ichi Nuclear Power Plant accident, radiation effects on nonhuman biota in the contaminated areas have been a great concern. The induction of chromosomal aberrations in splenic lymphocytes of small Japanese field mice (Apodemus argenteus) and house mice (Mus musculus) inhabiting Fukushima Prefecture was investigated. In mice inhabiting the slightly contaminated area, the average frequency of dicentric chromosomes was similar to that seen in mice inhabiting a noncontaminated control area. In contrast, mice inhabiting the moderately and heavily contaminated areas showed a significant increase in the average frequencies of dicentric chromosomes. Total absorbed dose rate was estimated to be approximately 1 mGy d(-1) and 3 mGy d(-1) in the moderately and heavily contaminated areas, respectively. Chromosomal aberrations tended to roughly increase with dose rate. Although theoretically, the frequency of chromosomal aberrations was considered proportional to the absorbed dose, chromosomal aberrations in old mice (estimated median age 300 days) did not increase with radiation dose at the same rate as that observed in young mice (estimated median age 105 days).


Subject(s)
Chromosome Aberrations , Fukushima Nuclear Accident , Nuclear Power Plants , Radioactive Pollutants/analysis , Animals , Arvicolinae , Cell Cycle/radiation effects , Chromosomes, Mammalian/genetics , Dose-Response Relationship, Radiation , Lymphocytes/cytology , Lymphocytes/radiation effects , Metaphase/radiation effects , Mice , Radiation Monitoring
8.
J Environ Radioact ; 142: 124-31, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25666988

ABSTRACT

The dose rates of radiation absorbed by wild rodents inhabiting a site severely contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident were estimated. The large Japanese field mouse (Apodemus speciosus), also called the wood mouse, was the major rodent species captured in the sampling area, although other species of rodents, such as small field mice (Apodemus argenteus) and Japanese grass voles (Microtus montebelli), were also collected. The external exposure of rodents calculated from the activity concentrations of radiocesium ((134)Cs and (137)Cs) in litter and soil samples using the ERICA (Environmental Risk from Ionizing Contaminants: Assessment and Management) tool under the assumption that radionuclides existed as the infinite plane isotropic source was almost the same as those measured directly with glass dosimeters embedded in rodent abdomens. Our findings suggest that the ERICA tool is useful for estimating external dose rates to small animals inhabiting forest floors; however, the estimated dose rates showed large standard deviations. This could be an indication of the inhomogeneous distribution of radionuclides in the sampled litter and soil. There was a 50-fold difference between minimum and maximum whole-body activity concentrations measured in rodents at the time of capture. The radionuclides retained in rodents after capture decreased exponentially over time. Regression equations indicated that the biological half-life of radiocesium after capture was 3.31 d. At the time of capture, the lowest activity concentration was measured in the lung and was approximately half of the highest concentration measured in the mixture of muscle and bone. The average internal absorbed dose rate was markedly smaller than the average external dose rate (<10% of the total absorbed dose rate). The average total absorbed dose rate to wild rodents inhabiting the sampling area was estimated to be approximately 52 µGy h(-1) (1.2 mGy d(-1)), even 3 years after the accident. This dose rate exceeds 0.1-1 mGy d(-1) derived consideration reference level for Reference rat proposed by the International Commission on Radiological Protection (ICRP).


Subject(s)
Arvicolinae/metabolism , Cesium Radioisotopes/metabolism , Murinae/metabolism , Radiation Dosage , Radiation Exposure , Soil Pollutants, Radioactive/metabolism , Animals , Fukushima Nuclear Accident , Japan , Radiation Monitoring
9.
Ecol Evol ; 3(14): 4711-21, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24363899

ABSTRACT

For maintaining social and financial support for eradication programs of invasive species, quantitative assessment of recovery of native species or ecosystems is important because it provides a measurable parameter of success. However, setting a concrete goal for recovery is often difficult owing to lack of information prior to the introduction of invaders. Here, we present a novel approach to evaluate the achievement level of invasive predator management based on the carrying capacity of endangered species estimated using long-term monitoring data. In Amami-Oshima Island, Japan, where the eradication project of introduced small Indian mongoose is ongoing since 2000, we surveyed the population densities of four endangered species threatened by the mongoose (Amami rabbit, the Otton frog, Amami tip-nosed frog, and Amami Ishikawa's frog) at four time points ranging from 2003 to 2011. We estimated the carrying capacities of these species using the logistic growth model combined with the effects of mongoose predation and environmental heterogeneity. All species showed clear tendencies toward increasing their density in line with decreased mongoose density, and they exhibited density-dependent population growth. The estimated carrying capacities of three endangered species had small confidence intervals enough to measure recovery levels by the mongoose management. The population density of each endangered species has recovered to the level of the carrying capacity at about 20-40% of all sites, whereas no individuals were observed at more than 25% of all sites. We propose that the present approach involving appropriate monitoring data of native organism populations will be widely applicable to various eradication projects and provide unambiguous goals for management of invasive species.

10.
Int J Geriatr Psychiatry ; 28(12): 1251-9, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23526542

ABSTRACT

OBJECTIVE: Metabolic syndrome contains many risks for medical diseases such as cardiovascular disease and diabetes, which might precipitate depressive symptoms in the older people. However, the association between depressive symptoms and metabolic syndrome in Japanese community-dwelling older people is unclear. This study was performed to answer this important question. METHODS: Cross-sectional analyses were performed on 3796 community-dwelling independent older people (≥ 65 years, 1911 men and 1885 women) from the 2007-2008 baseline examination of the Fujiwara-kyo study, a prospective cohort study on successful aging. Depressive symptoms were assessed using the 15-item short form of the Geriatric Depression Scale and metabolic syndrome was defined according to the 2005 International Diabetes Federation. Covariates were social supports, negative life events, health behavior, education, cognitive function, anthropometric status, and others. Multiple logistic regression analyses were performed to determine the relationships between depressive symptoms and these variables. RESULTS: The prevalence of depressive symptoms (Geriatric Depression Scale-15 ≥ 6) and metabolic syndrome were 14.8% and 16.6%, respectively. Significant protective factors against depressive symptoms were higher education, more opportunity for drinking of alcohol, better social supports, and more walking daily. Metabolic syndrome was statistically associated with depressive symptoms (adjusted odds ratio = \ 1.32, 95% confidence interval = 1.03-1.68). Other risk factors significantly associated with depressive symptoms were sleep disturbance, visual or hearing impairment, and negative life events. CONCLUSIONS: The present study showed an association between metabolic syndrome and depressive symptoms in ambulatory Japanese older people, as in western countries.


Subject(s)
Depressive Disorder/epidemiology , Metabolic Syndrome/epidemiology , Aged , Aged, 80 and over , Cross-Sectional Studies , Depressive Disorder/etiology , Female , Geriatric Assessment , Humans , Japan/epidemiology , Male , Metabolic Syndrome/psychology , Odds Ratio , Prevalence , Prospective Studies , Psychiatric Status Rating Scales
11.
Chromosome Res ; 20(1): 111-25, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22198613

ABSTRACT

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. Using cross-species fluorescence in situ hybridization (Zoo-FISH), we found that both short arms of the T. muenninki sex chromosomes were painted by probes from mouse chromosomes 11 and 16. Comparative genomic hybridization analysis was unable to detect sex-specific regions in the sex chromosomes because both sex probes highlighted the large heterochromatic blocks on the Y chromosome as well as five autosomal pairs. We then performed comparative FISH mapping using 29 mouse complementary DNA (cDNA) clones of the 22 X-linked genes and the seven genes linked to mouse chromosome 11 (whose homologue had fused to the sex chromosomes), and FISH mapping using two T. muenninki cDNA clones of the Y-linked genes. This analysis revealed that the ancestral gene order on the long arm of the X chromosome and the centromeric region of the short arm of the Y chromosome were conserved. Whereas six of the mouse chromosome 11 genes were also mapped to Xp and Yp, in addition, one gene, CBX2, was also mapped to Xp, Yp, and chromosome 14 in T. muenninki. CBX2 is the candidate gene for the novel sex determination system in the two other species of Tokudaia, which lack a Y chromosome and SRY gene. Overall, these results indicated that the Y chromosome of T. muenninki avoided a loss event, which occurred in an ancestral lineage of T. osimensis and T. tokunoshimensis, through fusion with an autosome. Despite retaining the Y chromosome, sex determination in T. muenninki might not follow the usual mammalian pattern and deserves further investigation.


Subject(s)
Artificial Gene Fusion/methods , Chromosome Structures/metabolism , Murinae/genetics , Y Chromosome/genetics , Animals , Cells, Cultured , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/metabolism , Chromosome Mapping , Chromosome Painting/methods , Chromosome Structures/genetics , Comparative Genomic Hybridization , DNA Probes/metabolism , DNA, Complementary/genetics , DNA, Complementary/metabolism , Endangered Species , Female , Gene Duplication , Gene Order , Karyotype , Male , Mice , Sex Determination Processes
12.
Chromosome Res ; 19(5): 635-44, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21656076

ABSTRACT

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 identify a candidate gene that controls this mechanism, the copy numbers and chromosomal locations of 10 genes with important functions in gonadal differentiation were determined: ATRX, CBX2 (M33), DMRT1, FGF9, NR0B1 (DAX1), NR5A1 (Ad4BP/SF1), RSPO1, SOX9, WNT4, and WT1. Multiple bands were detected for NR0B1 in Southern blot analysis, which suggested the presence of multiple copies of the gene in the genomes of these two species. CBX2 was localized to two loci in both sexes of the two species by fluorescence in situ hybridization mapping: 3q24 and 6p11.2 in T. osimensis and 10q25-q26 and 14q12-q13.1 in T. tokunoshimensis. Quantification of copy numbers in the two species by quantitative real-time PCR indicated that there were two or three more copies of CBX2 per haploid genome in males (T. osimensis, n = 3; T. tokunoshimensis, n = 2) than in females (T. osimensis, n = 4; T. tokunoshimensis, n = 2), whereas NR0B1 was present as a single copy in both. The results suggest that additional copies of CBX2 in males might be involved in a novel sex-determining mechanism in species that lack SRY.


Subject(s)
DAX-1 Orphan Nuclear Receptor/genetics , Genome/genetics , Murinae/genetics , Repressor Proteins/genetics , Animals , Blotting, Southern , Chromosome Mapping , Chromosomes, Mammalian/genetics , Female , Gene Dosage , In Situ Hybridization, Fluorescence , Male , Murinae/classification , Polycomb-Group Proteins , RNA, Long Noncoding , RNA, Untranslated/genetics , Sex Determination Processes , Sex-Determining Region Y Protein/genetics , Species Specificity
13.
Chromosome Res ; 18(6): 623-34, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20574822

ABSTRACT

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 sex chromosomes in T. muenninki. Therefore, we constructed molecular phylogenetic trees with nucleotide sequences of cyt b, RAG1, and IRBP. All trees strongly supported that T. muenninki was the first to diverge from the Tokudaia ancestor, indicating that loss of the Y chromosome and SRY occurred in the common ancestor of the two XO/XO species after T. muenninki diverged. We found that the X and Y chromosomes of T. muenninki consisted of large euchromatic and heterochromatic regions by conducting G- and C-banding analyses. PCR, Southern blotting, and FISH revealed that T. muenninki males had multiple SRY copies on the long arm of the Y chromosome. At least three of 24 SRY sequences contained a complete open reading frame (ORF). A species-specific substitution from alanine to serine was found in all copies at the DNA-binding surface within the HMG-box, suggesting that it occurred in an original SRY.


Subject(s)
Genes, sry , Murinae/genetics , Phylogeny , Sex-Determining Region Y Protein/genetics , Y Chromosome , Amino Acid Sequence , Animals , Base Sequence , Cytogenetic Analysis , DNA-Binding Proteins/genetics , Evolution, Molecular , Female , Gene Dosage , Genes, RAG-1 , HMGB Proteins/chemistry , HMGB Proteins/physiology , Male , Molecular Sequence Data , Sequence Analysis, DNA , X Chromosome
14.
Chromosoma ; 119(5): 519-26, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20443119

ABSTRACT

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 a processed pseudogene on autosome. In contrast, EIF2S3Y and KDM5D were conserved in genomes of both sexes as a result of their translocation from the Y chromosome to the X chromosome and/or autosomes. Furthermore, these genes were expressed in gonads and brains of both sexes. Our study indicated a loss of Y-linked genes with important male functions to be necessary for the Y chromosome to disappear. These functions might have been retained through the acquisition of new genes, and therefore, the Y-loss has had no harmful effect on the maintenance of this species.


Subject(s)
Genes, Y-Linked , Murinae/genetics , Translocation, Genetic , Y Chromosome/genetics , Animals , Base Sequence , Chromosome Mapping , Cytogenetic Analysis , DNA-Binding Proteins/genetics , Female , Gene Expression , Genes, X-Linked , Genes, sry , Humans , In Situ Hybridization, Fluorescence , Male , Meiosis , Mice , Nuclear Proteins/genetics , Pseudogenes , Sex Chromosome Aberrations , Sex-Determining Region Y Protein/genetics , Spermatogenesis , X Chromosome/genetics , Y Chromosome/ultrastructure
15.
Am J Surg Pathol ; 32(5): 784-92, 2008 May.
Article in English | MEDLINE | ID: mdl-18379415

ABSTRACT

This report describes an unusual case of mammary intraductal papillomas coexistent with sentinel lymph node papilloma. A 47-year-old Japanese female underwent 5 needle manipulations and 2 surgical biopsies for recurring papillomas in the right breast over 5 years before having a simple mastectomy. During the mastectomy, the ipsilateral sentinel node was found to be extensively occupied by completely benign papilloma that measured 6 mm in its greatest dimension. The clinical history led us to put forward the working hypothesis that the nodal papillary lesion may develop from the epithelial cells that are displaced from the mammary papillomas during needle procedures and mechanically transported to the sentinel lymph node. To test the hypothesis, we retrieved surgical biopsies (dochectomy and excisional biopsy), mastectomy, and sentinel lymph node specimens for histopathologic, immunohistochemical, and molecular studies. The presence of myoepithelial layer in each papillary tumor was confirmed by immunostains with specific myoepithelial markers, p63 and CD10. The excisional biopsy specimen exhibited displaced fragments of benign epithelial cells within granulation tissue at the needle manipulation site, indicating that iatrogenic epithelial cell displacement did occur in this case. However, loss of heterozygosity at 16p13 and 16q21 was only observed in the papillomas of the dochectomy and the excisional biopsy; no loss of heterozygosity was detected in the papillomas of the mastectomy and the sentinel lymph node. It remains undetermined whether the nodal papilloma was derived from the papilloma of the mastectomy or if it arose de novo from the breast tissue inclusion of the sentinel node.


Subject(s)
Breast Neoplasms/pathology , Lymph Nodes/pathology , Papilloma, Intraductal/secondary , Sentinel Lymph Node Biopsy , Axilla , Biomarkers, Tumor/analysis , Breast Neoplasms/chemistry , Breast Neoplasms/genetics , DNA, Neoplasm/analysis , Female , Humans , Lymph Nodes/chemistry , Lymphatic Metastasis , Mastectomy , Middle Aged , Neoplasm Recurrence, Local , Papilloma, Intraductal/chemistry , Papilloma, Intraductal/genetics
16.
Chromosome Res ; 16(4): 587-93, 2008.
Article in English | MEDLINE | ID: mdl-18432393

ABSTRACT

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 inversion event occurred in the X chromosome of either species. To identify X chromosome rearrangements that have occurred between the two species, we mapped 22 mouse cDNA clones of the X-linked genes on the chromosomes of the two species by direct R-banding FISH. The gene orders of the X chromosomes were conserved in the two species, whereas the position of the centromere on the X chromosome was different. This result indicates that the rearrangement which occurred in either of the X chromosomes after the two species diverged from a common ancestor involved not pericentric inversion but centromere repositioning.


Subject(s)
Centromere/metabolism , Chromosomes, Mammalian/metabolism , Mammals/genetics , X Chromosome/metabolism , Animals , Chromosome Mapping , Clone Cells , Cytogenetic Analysis , DNA, Complementary/genetics , Female , Genes, X-Linked , In Situ Hybridization, Fluorescence , Male , Mice , Rats
17.
Chromosome Res ; 15(6): 799-806, 2007.
Article in English | MEDLINE | ID: mdl-17874214

ABSTRACT

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 different: the diploid chromosome numbers and sex chromosome constitution are 2n=45, X0/X0 for T. tokunoshimensis and 2n=25, X0/X0 for T. osimensis. We conducted comparative chromosome painting with chromosome-specific DNA probes of the laboratory mouse (Mus musculus) to molecularly examine the chromosome homology between T. tokunoshimensis and T. osimensis, and deduced a possible ancestral karyotype of Tokudaia species and the process of evolutionary chromosome rearrangements. The proposed ancestral karyotype with the diploid number of 2n=48, XX/XY was similar to the karyotype of T. tokunoshimensis, and the karyotype of T. osimensis would then have been established through at least 14 chromosomal changes, mainly centric fusion and tandem fusion, from the ancestral karyotype. The close karyological relationship between the ancestral karyotypes of Tokudaia and Apodemus also suggests that the chromosomal evolution in the Tokudaia-Apodemus lineage has been very slow and has accelerated only recently in the branch leading to T. osimensis.


Subject(s)
Chromosome Painting/methods , Animals , Chromosome Banding , Chromosome Mapping , Chromosomes/ultrastructure , DNA/chemistry , Diploidy , Karyotyping , Mice , Muridae , Murinae , Rats , Rodentia , Species Specificity
18.
Chromosome Res ; 15(2): 175-87, 2007.
Article in English | MEDLINE | ID: mdl-17294259

ABSTRACT

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 with no cytogenetically visible Y chromosome in both sexes. We constructed the standard ideograms for these species at the 100 and 200 band levels. Comparing the banding patterns between these species, it was suggested that at least 10 times the number of Robertsonian fusions occurred in T. osimensis chromosomes. However, no karyotypic differences were observed between sexes in each species. To detect the sex-specific chromosomal region of these X0 species we applied the comparative genomic hybridization (CGH) method. Although the male- and female-derived gains and losses were detected in several chromosome regions, all of them were located in the heterochromatic and/or telomeric regions. This result suggested that the differences detected by CGH might be caused by the polymorphism on the copy numbers of repeated sequences in the heterochromatic and telomeric regions. Our result indicated that the sex-specific region, where the key to sex determination lies, is very minute in X0 species of Tokudaia.


Subject(s)
Chromosomes, Mammalian , Murinae/genetics , Sex Determination Processes , X Chromosome , Animals , Biological Evolution , Cells, Cultured , Chromosome Banding , Cytogenetic Analysis , Female , Fibroblasts/cytology , Heterochromatin , Japan , Male , Nucleic Acid Hybridization , Species Specificity , Telomere , Translocation, Genetic
19.
Environ Pollut ; 140(3): 525-35, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16159690

ABSTRACT

The present study determined the contamination levels and congener-specific accumulation features of dioxins and related compounds (DRCs) in wild terrestrial mammals such as large Japanese field mice (LJFM), lesser Japanese moles (LJMs), and raccoon dogs (RDs) collected from Kanto region in Japan during 2001. The toxic equivalent quantity (TEQ) levels in the carcasses or adipose tissues were in the order of RDs > or = LJMs > LJFM. Comparison of DRC congener profiles in the three species and principal component analysis (PCA) demonstrated a higher contribution of OCDD, T4CB77, and P5CB118 in LJMs. Analysis of liver-adipose distribution of DRC congeners in RDs showed that livers contained significantly higher TEQs than adipose tissues, indicating that liver is a depository organ and critical for determining the toxicokinetics of DRCs. As for most T4, P5, H6CDD/DFs and for P5CB126, H6CB169 and mono-ortho PCB congeners, their liver/adipose concentration ratios in RDs revealed a tendency to increase with hepatic TEQ levels, suggesting TEQ-dependent hepatic sequestration.


Subject(s)
Animals, Wild/metabolism , Environmental Pollutants/analysis , Liver/chemistry , Adipose Tissue/chemistry , Animals , Benzofurans/analysis , Dibenzofurans, Polychlorinated , Dioxins/analysis , Environmental Monitoring/methods , Female , Japan , Male , Moles , Murinae , Polychlorinated Biphenyls/analysis , Polychlorinated Dibenzodioxins/analogs & derivatives , Polychlorinated Dibenzodioxins/analysis , Principal Component Analysis , Raccoon Dogs , Soil Pollutants/analysis , Species Specificity
20.
Nat Prod Rep ; 22(1): 73-103, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15692618

ABSTRACT

This review covers newly isolated simple indole alkaloids, structure determinations, total syntheses and biological activities reported in the literature in 2003.


Subject(s)
Indole Alkaloids , Terpenes/chemistry , Carbazoles/chemistry , Carbolines/chemistry , Molecular Structure , Peptides/chemistry
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