Sample records for abnormal sex chromosome

  1. Abnormal human sex chromosome constitutions

    SciTech Connect

    NONE

    1993-12-31

    Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

  2. Sex chromosomes and their abnormalities

    E-print Network

    Dellaire, Graham

    -X-Y pairing in meiosis SRY gene-testis determining factor Fewer than 50 genes-most related to gonadal In the presence of Y chromosome (TDF), testis develop Androgens complexed with 5a- reductase bind to the androgen linked recessive disease, it would be expressed in females Norandom X-inactivation Identifies carriers

  3. Parental decisions following the prenatal diagnosis of sex chromosome abnormalities

    Microsoft Academic Search

    Hanan A Hamamy; Sophie Dahoun

    2004-01-01

    Objective: To report parental decisions regarding pregnancy termination following the prenatal diagnosis of a sex chromosome abnormality (SCA) in the fetus. Methods: Retrospective collection of data from records of 61 families receiving genetic counseling after prenatal diagnosis of a sex chromosome abnormality in the fetus in the Division of Medical Genetics, University Hospital of Geneva during the time period 1980–2001.

  4. Cognitive and academic skills in children with sex chromosome abnormalities

    Microsoft Academic Search

    Bruce G. Bender; Mary Linden; Arthur Robinson

    1991-01-01

    Forty-six unselected children with various sex chromosome abnormalities (14 boys with 47,XXY, 4 boys with 47,XYY, 11 girls with 47,XXX, 9 girls with 45,X, and 8 girls with SCA mosaicism), identified through the consecutive chromosome screening of 40,000 Denver newborns, have been followed developmentally and evaluated in a protocol that included intellectual, language, and achievement testing. Controls consisted of 12

  5. Cognitive and Academic Skills in Children with Sex Chromosome Abnormalities

    Microsoft Academic Search

    Bruce G. Bender; Mary Linden; Arthur Robinson

    \\u000a Forty-six unselected children with various sex chromosome abnormalities (14 boys with 47, XXY, 4 boys with 47, XYY, 11 girls\\u000a with 47, XXX, 9 girls with 45, X, and 8 girls with SCA mosaicism), identified through the consecutive chromosome screening\\u000a of 40,000 Denver newborns, have been followed developmentally and evaluated in a protocol that included intellectual, language,\\u000a and achievement testing.

  6. Neuropsychological impairment in 42 adolescents with sex chromosome abnormalities

    Microsoft Academic Search

    Bruce G. Bender; Mary G. Linden; Arthur Robinson

    1993-01-01

    Sixty-seven adolescents participated in this protocol, including 42 with sex chromosome abnormalities and 25 controls. Results from a battery of neuropsychological tests indicated karyotype specific patterns of logical impairment: (1) 47,XXY boys had un- impaired intelligence but reduced abilities in verbal fluency and reading; (2) 47,XXX girls experienced reduced general intelligence ac- companied by impaired scores on individual tests of

  7. Parental Decisions of Prenatally Detected Sex Chromosome Abnormality

    Microsoft Academic Search

    Jung-Yeol Han; Moon-Young Kim; Jae-Hyug Yang; Kyu-Hong Choi; Young-Mi Kim; Jin-Mee Kim; Hyun-Mee Ryu; Samsung Cheil

    Because of the widespread use of amniocentesis, the prenatal recognition of sex chromosome abnormality (SCA) has become increasingly common. Recent lit- erature provided an insight into the understanding of the natural history and prog- nosis for individuals with SCA. Our study was designed to review the parental decision on pregnancy with SCA. Over the last 10 yr, we diagnosed 38

  8. Mental development of unselected children with sex chromosome abnormalities

    Microsoft Academic Search

    J. Nielsen; A. M. Sřrensen; K. Sřrensen

    1981-01-01

    Twenty-five children with sex chromosome aberrations found among 11000 consecutively newborn children from 1969 to 1974 have been followed with psychologicalpsychiatric examinations at four different times from the age of 1 year till the ages of 7 to 11. The results of the follow-up studies are presented, and it is concluded that diagnosis of sex chromosome aberrations at birth or

  9. Neuropsychological impairment in 42 adolescents with sex chromosome abnormalities.

    PubMed

    Bender, B G; Linden, M G; Robinson, A

    1993-10-15

    Sixty-seven adolescents participated in this protocol, including 42 with sex chromosome abnormalities and 25 controls. Results from a battery of neuropsychological tests indicated karyotype specific patterns of neuropsychological impairment: (1) 47,XXY boys had unimpaired intelligence but reduced abilities in verbal fluency and reading; (2) 47,XXX girls experienced reduced general intelligence accompanied by impaired scores on individual tests of attention, concept formation, spatial thinking, verbal fluency, and academic skills, while retention of memorized information was a relative strength; (3) among the 45,X girls average intelligence level was also reduced along with scores on tests of attention, concept formation, verbal fluency, spatial thinking, and academic skills, and an atypical pattern of hand dominance was identified; (4) test scores in the group of mosaic females did not differ from those of controls. Test scores and patterns of personal adaptation were quite variable in all groups; while eight nonmosaic propositi required intensive special education assistance in their public schooling, eight others have attended college. PMID:8291574

  10. Chromosomal abnormalities

    SciTech Connect

    Goh, K.; Jacox, R.F.; Anderson, F.W.

    1980-09-01

    Cytogenetic studies from the peripheral blood of a patient with malignant lymphoma and rhematoid arthritis who was treated with intra-articular gold Au 198 revealed mosaicism with a normal female metaphase and a 43-chromosome metaphase. The abnormal cell line showed six missing normal chromosomes and three morphologically abnormal chromosomes. The trypsin-digested G-banding metaphases showed that the marker chromosomes were an isochromosome of the long arm of chromosome 17, a translocated chromosome that involved the long arm of chromosome 4 and a chromosome 16, and a translocated chromosome that involved the long arm of chromosome 4 and a chromosome 5. It is tempting to conclude that these abnormalities were due to the gold Au 198 treatment, but we cannot exclude other possibilities.

  11. Non-invasive prenatal testing for sex chromosome abnormalities: a source of confusion.

    PubMed

    Kalafat, Erkan; Seval, Mehmet Murat; Turgay, Batuhan; Koç, Acar

    2015-01-01

    Cell-free fetal DNA has received significant attention for the purposes of prenatal genetic testing in the past decade. Fetal DNA testing is a new method and promising for many applications such as aneuploidy screening, prenatal diagnosis, prediction of preeclampsia and more. A 37-year-old primigravida, with a pregnancy conceived by intracytoplasmic sperm injection (ICSI), was offered non-invasive prenatal testing (NIPT) due to advanced maternal age. NIPT performed at 23?weeks' gestation reported a diagnosis of monosomy X. She was offered an amniocentesis, which revealed a euploid fetus with no sex chromosome abnormalities. Even with single nucleotide polymorphism-based NIPT, positive predictive value for detection of sex chromosome abnormalities is around 50%. Positive results of NIPT should be heeded with caution and an invasive diagnostic procedure should be performed, especially for rare chromosomal abnormalities and sex chromosome abnormalities where NIPT performs subpar compared to its performance for detection of trisomy 21. PMID:25631759

  12. Head circumference and IQ of children with sex chromosome abnormalities.

    PubMed

    Ratcliffe, S G; Masera, N; Pan, H; McKie, M

    1994-06-01

    At all ages XXX girls had significantly smaller head circumferences than control girls. Their IQ deficit was 24 points and IQ at age seven correlated significantly with head circumference at birth. In XXY boys, head circumference was significantly reduced at birth and up to nine years of age. The XXY boys' IQ deficit was 22 points, but IQ did not correlate with head circumference, as reductions in the two parameters did not always occur in tandem. The ratio of height-to-head circumference differed most in this group and could be useful in clinical recognition of this condition. XYY boys' head size did not differ from controls, despite their greater height, lower IQ scores indicating an adverse effect of an additional Y chromosome on brain development. The major factor affecting IQ outcome in the cohort was abnormal karyotype, with smaller effects from social class and head growth. PMID:8005365

  13. Follow-up till age 3–4 of unselected children with sex chromosome abnormalities

    Microsoft Academic Search

    Johannes Nielsen; Ingelise Sillesen

    1976-01-01

    Follow-up examination of 15 unselected children with aneuploid sex chromosome abnormalities has been made till between the age of 21\\/2 and 5 years. The mental development of the 15 children was in all cases within the normal range, but there was a tendency to some differences compared with their siblings.

  14. Prenatal Diagnosis of Sex Chromosome Abnormalities: The 8Year Experience of a Single Medical Center

    Microsoft Academic Search

    Zvi Vaknin; Orit Reish; Ido Ben-Ami; Eli Heyman; Arie Herman; Ron Maymon

    2008-01-01

    Objective: To assess the indications for prenatal karyotyping of sex chromosomal abnormalities (SCAs) during pregnancy. Methods: All singleton pregnancies interrupted in our institute because of SCAs (1998–2005) were categorized into subgroups of 45,XO (Turner syndrome), 47,XXY (Klinefelter syndrome), 47,XXX and 47,XYY. The indications for prenatal diagnostic testing were recorded. Results: There were 67 SCAs pregnancies: 33% Turner syndrome, 28% Klinefelter

  15. Chromosome Abnormalities

    MedlinePLUS

    ... division. There are two kinds of cell division, mitosis and meiosis. Mitosis results in two cells that are duplicates of ... 23 paired sets of chromosomes in nonreproductive cells. Mitosis: Cell division resulting in cells that have paired ...

  16. Infertile mares with chromosome abnormalities

    Microsoft Academic Search

    I. A. Stewart-Scott

    1988-01-01

    Chromosomal abnormalities have been detected in five mares identified by their poor reproductive performance. All had small gonads and absent or irregular oestrous cycles. One mare was 65, XXX, two were 64, XY sex-reversal females and two were sex chromosome mosaics with karyotypes of 63, XO\\/64, XX\\/64, XY and 63, XO\\/64, XX respectively. This report supports the suggestion made in

  17. Diversity of sex chromosome abnormalities in a cohort of 95 Indonesian patients with monosomy X

    PubMed Central

    2011-01-01

    Background Monosomy × or 45,X is a cytogenetic characteristic for Turner syndrome. This chromosome anomaly is encountered in around 50% of cases, but wide variations of other anomalies have been found. This report is to describe the cytogenetic characteristics of 45,X individuals. To the best of our knowledge, there were no large series of 45,X cases has been reported from Indonesia. Results Ninety five cases with 45,X cell line found, of which 60 were detected by karyotyping, 4 by FISH for sex chromosomes, and 31 by both karyotyping and FISH. Using karyotyping 37 out of 91 cases(40.6%) were identified as 45,X individuals, while cases who underwent FISH only 4 out of 35 cases (11.4%) showed 45,X result, resulting in total of 39 45,X cases (41.1%), and the rest 56 (58.9%) cases are mosaic. Among these cases, 21 out of 95 (22.1%) have Y or part of Y as the second or third sex chromosome in their additional cell lines. Result discrepancies revealed in 22 out of 31 cases who underwent both FISH and karyotyping, of which 7 showed normal 46,XX or 46,XY karyotypes, but by FISH, additional monosomy × cell line was found. Most of the cases were referred at the age of puberty (8-13 years old) or after that (14-18 years old), 31 and 21 cases respectively, and there were 14 cases were sent in adulthood. Conclusion Wide variations of sex chromosome aberrations have been detected using the combination of conventional cytogenetic and FISH, including detection of low level of mosaicism and Y-chromosome fragments. Result discrepancies using both techniques were found in 22/31 cases, and in order to obtain a more details of sex chromosome constitution of individuals with 45,X cell line both FISH and karyotyping should be carried out simultaneously. PMID:21992692

  18. Verbal and spatial processing efficiency in 32 children with sex chromosome abnormalities.

    PubMed

    Bender, B G; Linden, M G; Robinson, A

    1989-06-01

    Spatial and linguistic processing efficiency was evaluated in sixty 8- to 18-yr-old children, including thirteen 47,XXY boys, eleven 47,XXX girls, six girls with 45,X, two girls with 46,X,Xq-, and 28 chromosomally normal controls. Results indicated that the 47,XXX girls performed significantly below controls on all four cognitive tests. Scores of the X monosomy group were reduced on both spatial tests, one requiring rapid information processing and one without time requirements, which is consistent with previous reports of spatial thinking deficits in these propositae. The X monosomy girls also had difficulty completing the high efficiency but not the low efficiency verbal tests. Scores in the 47,XXY group did not differ from controls on either spatial test or on the low efficiency verbal task. When required to rapidly access verbal information from memory, however, the performance of these boys was significantly impaired. This finding confirms earlier reports of impeded verbal fluency in these propositi. Alteration in capacity to rapidly process information appears to distinguish 47,XXY boys and X monosomy girls from their chromosomally normal peers, and suggests that adaptations in their educational setting should be introduced to allow additional time to learn and complete work. PMID:2740147

  19. Chromosomal abnormalities in human sperm

    SciTech Connect

    Martin, R.H.

    1985-01-01

    The ability to analyze human sperm chromosome complements after penetration of zona pellucida-free hamster eggs provides the first opportunity to study the frequency and type of chromosomal abnormalities in human gametes. Two large-scale studies have provided information on normal men. We have studied 1,426 sperm complements from 45 normal men and found an abnormality rate of 8.9%. Brandriff et al. (5) found 8.1% abnormal complements in 909 sperm from 4 men. The distribution of numerical and structural abnormalities was markedly dissimilar in the 2 studies. The frequency of aneuploidy was 5% in our sample and only 1.6% in Brandriff's, perhaps reflecting individual variability among donors. The frequency of 24,YY sperm was low: 0/1,426 and 1/909. This suggests that the estimates of nondisjunction based on fluorescent Y body data (1% to 5%) are not accurate. We have also studied men at increased risk of sperm chromosomal abnormalities. The frequency of chromosomally unbalanced sperm in 6 men heterozygous for structural abnormalities varied dramatically: 77% for t11;22, 32% for t6;14, 19% for t5;18, 13% for t14;21, and 0% for inv 3 and 7. We have also studied 13 cancer patients before and after radiotherapy and demonstrated a significant dose-dependent increase of sperm chromosome abnormalities (numerical and structural) 36 months after radiation treatment.

  20. A Case of ADHD and a Major Y Chromosome Abnormality

    ERIC Educational Resources Information Center

    Mulligan, Aisling; Gill, Michael; Fitzgerald, Michael

    2008-01-01

    Background: ADHD is a common, heritable disorder of childhood. Sex chromosome abnormalities are relatively rare conditions that are sometimes associated with behavioral disorders. Method: The authors present a male child with ADHD and a major de-novo Y chromosome abnormality consisting of deletion of the long arm and duplication of the short arm.…

  1. Abnormal pairing of X and Y sex chromosomes during meiosis I in interspecific hybrids of Phodopus campbelli and P. sungorus.

    PubMed

    Ishishita, Satoshi; Tsuboi, Kazuma; Ohishi, Namiko; Tsuchiya, Kimiyuki; Matsuda, Yoichi

    2015-01-01

    Hybrid sterility plays an important role in the maintenance of species identity and promotion of speciation. Male interspecific hybrids from crosses between Campbell's dwarf hamster (Phodopus campbelli) and the Djungarian hamster (P. sungorus) exhibit sterility with abnormal spermatogenesis. However, the meiotic phenotype of these hybrids has not been well described. In the present work, we observed the accumulation of spermatocytes and apoptosis of spermatocyte-like cells in the testes of hybrids between P. campbelli females and P. sungorus males. In hybrid spermatocytes, a high frequency of asynapsis of X and Y chromosomes during the pachytene-like stage and dissociation of these chromosomes during metaphase I (MI) was observed. No autosomal univalency was observed during pachytene-like and MI stages in the hybrids; however, a low frequency of synapsis between autosomes and X or Y chromosomes, interlocking and partial synapsis between autosomal pairs, and ?-H2AFX staining in autosomal chromatin was observed during the pachytene-like stage. Degenerated MI-like nuclei were frequently observed in the hybrids. Most of the spermatozoa in hybrid epididymides exhibited head malformation. These results indicate that the pairing of X and Y chromosomes is more adversely affected than that of autosomes in Phodopus hybrids. PMID:25801302

  2. Distribution of ? 1 -(PI) phenotypes in chromosome abnormalities

    Microsoft Academic Search

    John C. Mulley; Grant R. Sutherland

    1981-01-01

    PI phenotypes (including subtypes) were determined for 168 individuals with chromosomal abnormalities ascertained in Adelaide. These included patients with mosaicism, trisomy 21, trisomy 13, trisomy 18, and various sex chromosome aberrations (45,X, 47,XXX, 47,XXY, 47,XYY, and 48,XXXY). Data did not support an existing proposition that mildly deficient PI phenotypes predispose to abnormal chromosome segregation during mitosis or meiosis. Phenotypic distributions

  3. SEX CHROMOSOMES IN FLOWERING PLANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sex chromosomes in dioecious and polygamous plants evolved as a mechanism for ensuring outcrossing to increase genetic variation in the offspring. Sex specificity has evolved in 75% of plant families by male sterile or female sterile mutations, but well defined heteromorphic sex chromosomes are know...

  4. Numerically abnormal chromosome constitutions in humans

    SciTech Connect

    NONE

    1993-12-31

    Chapter 24, discusses numerically abnormal chromosome constitutions in humans. This involves abnormalities of human chromosome number, including polyploidy (when the number of sets of chromosomes increases) and aneuploidy (when the number of individual normal chromosomes changes). Chapter sections discuss the following chromosomal abnormalities: human triploids, imprinting and uniparental disomy, human tetraploids, hydatidiform moles, anomalies caused by chromosomal imbalance, 13 trisomy (D{sub 1} trisomy, Patau syndrome), 21 trisomy (Down syndrome), 18 trisomy syndrome (Edwards syndrome), other autosomal aneuploidy syndromes, and spontaneous abortions. The chapter concludes with remarks on the nonrandom participation of chromosomes in trisomy. 69 refs., 3 figs., 4 tabs.

  5. Schizophrenia and Sex Chromosome Anomalies

    Microsoft Academic Search

    Lynn E. DeLisi; Ursula Friedrich; Jan Wahlstrom; Angela Boccio-Smith; Anders Foreman; Kurt Eklund; Timothy J. Crow

    1994-01-01

    An apparent excess of sex chromosome aneuploidies (XXY, XXX, and possibly XYY) has been reported in populations of patients with schizophrenia by a number of authors. These reports have received little attention because transmission of psychosis is regarded as autosomal and not sex linked, and the detection of extra X chromosomes by Barr body estimation alone is not a reliable

  6. RESEARCH Open Access Sex chromosome complement regulates

    E-print Network

    Sibille, Etienne

    RESEARCH Open Access Sex chromosome complement regulates expression of mood-related genes Marianne-related factors (sex chromosome complement, developmental gonadal sex, or adult circulating hormones) to frontal is determined by sex chromosome complement, the role of sex chromosomes cannot be investigated individually

  7. Gonadal sex chromosome complement in individuals with sex chromosomal and/or gonadal disorders

    SciTech Connect

    Bridge, J.A.; Sanger, W.G.; Seemayer, T. [Univ. of Nebraska Medical Center, Omaha, NE (United States)] [and others

    1994-09-01

    Gonadal abnormalities are characteristically seen in patients with sex chromosomal aneuploidy. Morphologically these abnormalities can be variable and are hypothesized to be dependent on the sex chromosomal consititution of the gonad (independent of the chromosomal complement of other tissues, such as peripheral blood lymphocytes). In this study, the gonadal sex chromosome complement was evaluated for potential mosaicism and correlated with the histopathology from 5 patients with known sex chromosomal and/or gonadal disorders. FISH techniques using X and Y chromosome specific probes were performed on nuclei extracted from paraffin embedded tissue. Gonadal tissue obtained from case 1 (a true hemaphroditic newborn) consisted of ovotestes and epididymis (left side) and ovary with fallopian tube (right side). Cytogenetic and FISH studies performed on blood, ovotestes and ovary revealed an XX complement. Cytogenetic analysis of blood from case 2, a 4-year-old with suspected Turner syndrome revealed 45,X/46,X,del(Y)(q11.21). FISH analysis of the resected gonads (histologically = immature testes) confirmed an X/XY mosaic complement. Histologically, the gonadal tissue was testicular. Severe autolysis prohibited successful analysis in the 2 remaining cases. In summary, molecular cytogenetic evaluation of gonadal tissue from individuals with sex chromosomal and/or gonadal disorders did not reveal tissue-specific anomalies which could account for differences observed pathologically.

  8. Sex chromosomes and human growth

    Microsoft Academic Search

    Lassi Alvesalo

    1997-01-01

    Studies on tooth crown size and structure of individuals with various sex chromosome anomalies and their normal male and\\u000a female relatives have demonstrated differential direct effects on growth of genes on the human X and Y chromosomes. The Y\\u000a chromosome promotes growth of both tooth enamel and dentin, whereas the effect of the X chromosome on tooth growth seems to

  9. Numerous Transitions of Sex Chromosomes in Diptera

    PubMed Central

    Vicoso, Beatriz; Bachtrog, Doris

    2015-01-01

    Many species groups, including mammals and many insects, determine sex using heteromorphic sex chromosomes. Diptera flies, which include the model Drosophila melanogaster, generally have XY sex chromosomes and a conserved karyotype consisting of six chromosomal arms (five large rods and a small dot), but superficially similar karyotypes may conceal the true extent of sex chromosome variation. Here, we use whole-genome analysis in 37 fly species belonging to 22 different families of Diptera and uncover tremendous hidden diversity in sex chromosome karyotypes among flies. We identify over a dozen different sex chromosome configurations, and the small dot chromosome is repeatedly used as the sex chromosome, which presumably reflects the ancestral karyotype of higher Diptera. However, we identify species with undifferentiated sex chromosomes, others in which a different chromosome replaced the dot as a sex chromosome or in which up to three chromosomal elements became incorporated into the sex chromosomes, and others yet with female heterogamety (ZW sex chromosomes). Transcriptome analysis shows that dosage compensation has evolved multiple times in flies, consistently through up-regulation of the single X in males. However, X chromosomes generally show a deficiency of genes with male-biased expression, possibly reflecting sex-specific selective pressures. These species thus provide a rich resource to study sex chromosome biology in a comparative manner and show that similar selective forces have shaped the unique evolution of sex chromosomes in diverse fly taxa. PMID:25879221

  10. Sex chromosomes and sex determination in Lepidoptera.

    PubMed

    Traut, W; Sahara, K; Marec, F

    2007-01-01

    The speciose insect order Lepidoptera (moths and butterflies) and their closest relatives, Trichoptera (caddis flies), share a female-heterogametic sex chromosome system. Originally a Z/ZZ (female/male) system, it evolved by chromosome rearrangement to a WZ/ZZ (female/male) system in the most species-rich branch of Lepidoptera, a monophyletic group consisting of Ditrysia and Tischeriina, which together comprise more than 98% of all species. Further sporadic rearrangements created multi-sex chromosome systems; sporadic losses of the W changed the system formally back to Z/ZZ in some species. Primary sex determination depends on a Z-counting mechanism in Z/ZZ species, but on a female-determining gene, Fem, in the W chromosome of the silkworm. The molecular mechanism is unknown in both cases. The silkworm shares the last step, dsx, of the hierarchical sex-determining pathway with Drosophila and other insects investigated, but probably not the intermediate steps between the primary signal and dsx. The W chromosome is heterochromatic in most species. It contains few genes and is flooded with interspersed repetitive elements. In interphase nuclei of females it is readily discernible as a heterochromatic body which grows with increasing degree of polyploidy in somatic cells. It is used as a marker for the genetic sex in studies of intersexes and Wolbachia infections. The sex chromosome system is being exploited in economically important species. Special strains have been devised for mass rearing of male-only broods in the silkworm for higher silk production and in pest species for the release of sterile males in pest management programs. PMID:18391545

  11. Sex Chromosomes and Sex Determination in Lepidoptera

    Microsoft Academic Search

    W. Traut; K. Sahara; F. Marec

    2007-01-01

    The speciose insect order Lepidoptera (moths and butterflies) and their closest relatives, Trichoptera (caddis flies), share a female-heterogametic sex chromosome system. Originally a Z\\/ZZ (female\\/male) system, it evolved by chromosome rearrangement to a WZ\\/ZZ (female\\/male) system in the most species-rich branch of Lepidoptera, a monophyletic group consisting of Ditrysia and Tischeriina, which together comprise more than 98% of all species.

  12. Advances in understanding paternally transmitted Chromosomal Abnormalities

    SciTech Connect

    Marchetti, F; Sloter, E; Wyrobek, A J

    2001-03-01

    Multicolor FISH has been adapted for detecting the major types of chromosomal abnormalities in human sperm including aneuploidies for clinically-relevant chromosomes, chromosomal aberrations including breaks and rearrangements, and other numerical abnormalities. The various sperm FISH assays have been used to evaluate healthy men, men of advanced age, and men who have received mutagenic cancer therapy. The mouse has also been used as a model to investigate the mechanism of paternally transmitted genetic damage. Sperm FISH for the mouse has been used to detect chromosomally abnormal mouse sperm, while the PAINT/DAPI analysis of mouse zygotes has been used to evaluate the types of chromosomal defects that can be paternally transmitted to the embryo and their effects on embryonic development.

  13. Chromosome abnormalities in Japanese quail embryos

    E-print Network

    Paris-Sud XI, Université de

    Chromosome abnormalities in Japanese quail embryos CA de la Sena NS Fechheimer KE Nestor The Ohio-Auzeville, 10-13 July 1990) Japanese quail / embryos / heteroploidy / chromosomes INTRODUCTION Embryos zygotes and the etiology of heteroploid zygotes and embryos (Fechheimer, 1981, 1990). The Japanese quail

  14. Fetal Calcifications Are Associated with Chromosomal Abnormalities

    PubMed Central

    Sahlin, Ellika; Sirotkina, Meeli; Marnerides, Andreas

    2015-01-01

    Objective The biological importance of calcifications occasionally noted in fetal tissues (mainly liver) at autopsy or ultrasound is largely unexplored. Previous reports hint at an association to infection, circulatory compromise, malformations or chromosomal abnormalities. To identify factors associated with calcifications, we have performed a case-control study on the largest cohort of fetuses with calcifications described thus far. Methods One-hundred and fifty-one fetuses with calcifications and 302 matched controls were selected from the archives of the Department of Pathology, Karolinska University Hospital. Chromosome analysis by karyotyping or quantitative fluorescence-polymerase chain reaction was performed. Autopsy and placenta reports were scrutinized for presence of malformations and signs of infection. Results Calcifications were mainly located in the liver, but also in heart, bowel, and other tissues. Fetuses with calcifications showed a significantly higher proportion of chromosomal abnormalities than controls; 50% vs. 20% (p<0.001). The most frequent aberrations among cases included trisomy 21 (33%), trisomy 18 (22%), and monosomy X (18%). A similar distribution was seen among controls. When comparing cases and controls with chromosomal abnormalities, the cases had a significantly higher prevalence of malformations (95% vs. 77%, p=0.004). Analyzed the other way around, cases with malformations had a significantly higher proportion of chromosomal abnormalities compared with controls, (66% vs. 31%, p<0.001). Conclusion The presence of fetal calcifications is associated with high risk of chromosomal abnormality in combination with malformations. Identification of a calcification together with a malformation at autopsy more than doubles the probability of detecting a chromosomal abnormality, compared with identification of a malformation only. We propose that identification of a fetal tissue calcification at autopsy, and potentially also at ultrasound examination, should infer special attention towards co-existence of malformations, as this would be a strong indicator for a chromosomal abnormality. PMID:25923652

  15. Ovarian dysgenesis in individuals with chromosomal abnormalities

    Microsoft Academic Search

    Christopher Cunniff; Kenneth Lyons Jones; Kurt Benirschke

    1991-01-01

    To understand better the pathogenesis of ovarian dysgenesis in individuals with abnormalities such as 45,X Turner syndrome, trisomy 13, and trisomy 18, we have examined microscopically the ovaries of 36 infants with a number of chromosomal abnormalities confirmed by karyotype analysis. All infants with trisomy 13, trisomy 18, triploidy, and 45,X were found to have severe ovarian dysgenesis characterized by

  16. Four families with immunodeficiency and chromosome abnormalities.

    PubMed Central

    Candy, D C; Hayward, A R; Hughes, D T; Layward, L; Soothill, J F

    1979-01-01

    Six children, with severe deficiency of some or all of the immunoglobulins and minor somatic abnormalities, had chromosomal abnormalities: (1) 45,XY,t(13q/18q), (2) 46,XY,21ps +, (3) two brothers 46,XY (inv. 7) (4) 45,X,t(11p/10p)/46X,iXq,t(11p/10p) and, (5) in addendum, 45,XX,-18;46,XX, r18. The chromosome abnormalities were detected in B- as well as T-lymphocytes (as evidenced by using both PHA- and PWM-stimulated cultures) in all probands, but one was mosaic in PHA culture, although all his PWM-stimulated cells were abnormal. Chromosomal variants were also detected in relatives of three and immunodeficiency in relatives of two. Images Fig. 1 Fig. 3 PMID:314782

  17. Sex Determination and Sex Chromosomes Differentiation Between Different Sexes Occurs Even in ________________________.

    E-print Network

    Cutler, Chris

    Sex Determination and Sex Chromosomes Differentiation Between Different Sexes Occurs Even Determination Some of these Genes are on the Sex Chromosomes but Others are ____________ . In Multi Chromosome) = Male Sex Chromosomes The role of in Sex Determination was Initially Discovered Early in the 20

  18. Klinefelter syndrome and other sex chromosomal aneuploidies

    Microsoft Academic Search

    Jeannie Visootsak; John M Graham Jr

    2006-01-01

    The term Klinefelter syndrome (KS) describes a group of chromosomal disorder in which there is at least one extra X chromosome to a normal male karyotype, 46,XY. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. Other sex chromosomal aneuploidies have also been described, although they are much less frequent,

  19. Cytogenetic studies in a population suspected to have chromosomal abnormalities

    Microsoft Academic Search

    V. C. Shah; D. S. Krishna Mutiny; Sabita K. Murthy

    1990-01-01

    The present study describes the cytogenetic findings in cases suspected with chromosomal abnormalities, in cases of mental\\u000a retardation, multiple congenital malformations, clinical features of Down’s syndrome, Klinefelters’s syndrome, Turner’s syndrome,\\u000a ambiguous sex, sterility, amenorrhea and history of repeated spontaneous abortions in couples. Cytogenetic studies were done\\u000a in 144 of the total 205 cases. In all, 57 (39.58%) were shown to

  20. B Chromosomes and Sex in Animals

    Microsoft Academic Search

    J. P. M. Camacho; M. Schmid; J. Cabrero

    2011-01-01

    Supernumerary (B) chromosomes are dispensable elements found in many eukaryote genomes in addition to standard (A) chromosomes. In many respects, B chromosomes resemble sex chromosomes, so that a common ancestry for them has frequently been suggested. For instance, B chromosomes in grasshoppers, and other insects, show a pycnotic cycle of condensation-decondensation during meiosis remarkably similar to that of the X

  1. Consequences of chromosomal abnormalities in tumor development.

    PubMed

    Sánchez-García, I

    1997-01-01

    This article highlights recent advances in the molecular structure and function of proteins that are activated or created by chromosomal abnormalities and discusses their possible role in tumor development. The molecular characterization of these proteins has revealed that tumor-specific fusion proteins are the consequence of most chromosome translocations associated with leukemias and solid tumors. An emerging common theme is that creation of these proteins disrupts the normal development of tumor-specific target cells by blocking apoptosis. These insights identify these chromosomal translocation-associated genes as potential targets for improved cancer therapies. PMID:9442903

  2. Chromosomal Abnormality in Men with Impaired Spermatogenesis

    PubMed Central

    Mierla, Dana; Jardan, Dumitru; Stoian, Veronica

    2014-01-01

    Background: Chromosomal abnormalities and Y chromosome microdeletions are regarded as two most frequent genetic causes associated with failure of spermatogenesis in the Caucasian population. Materials and Methods: To investigate the distribution of genetic defects in the Romanian population with azoospermia or severe oligozoospermia, karyotype analysis by G-banding was carried out in 850 idiopathic infertile men and in 49 fertile men with one or more children. Screening for microdeletions in the azoospermia factor (AZF) region of Y chromosome was performed by multiplex polymerase chain reaction (PCR) on a group of 67 patients with no detectable chromosomal abnormality. The results of the two groups were compared by a two-tailed Fisher’s exact test. Results: In our study chromosomal abnormalities were observed in 12.70% and 8.16% of infertile and fertile individuals respectively. Conclusion: Our data suggests that infertile men with severe azoospermia have higher incidences of genetic defects than fertile men and also patients from any other group. Infertile men with normal sperm present a higher rate of polymorphic variants. It is important to know whether there is a genetic cause of male infertility before patients are subjected to intracytoplasmic sperm injection (ICSI) or testicular sperm extraction (TESE)/ICSI treatment. PMID:24696767

  3. Chromosomal abnormalities in a psychiatric population

    SciTech Connect

    Lewis, K.E.; Lubetsky, M.J.; Wenger, S.L.; Steele, M.W. [Univ. of Pittsburgh Medical Center, PA (United States)

    1995-02-27

    Over a 3.5 year period of time, 345 patients hospitalized for psychiatric problems were evaluated cytogenetically. The patient population included 76% males and 94% children with a mean age of 12 years. The criteria for testing was an undiagnosed etiology for mental retardation and/or autism. Cytogenetic studies identified 11, or 3%, with abnormal karyotypes, including 4 fragile X positive individuals (2 males, 2 females), and 8 with chromosomal aneuploidy, rearrangements, or deletions. While individuals with chromosomal abnormalities do not demonstrate specific behavioral, psychiatric, or developmental problems relative to other psychiatric patients, our results demonstrate the need for an increased awareness to order chromosomal analysis and fragile X testing in those individuals who have combinations of behavioral/psychiatric, learning, communication, or cognitive disturbance. 5 refs., 1 fig., 2 tabs.

  4. X Chromosome Abnormalities and Cognitive Development: Implications for Understanding Normal Human Development.

    ERIC Educational Resources Information Center

    Walzer, Stanley

    1985-01-01

    Argues that knowledge from studies of individuals with sex chromosome abnormalities can further understanding of aspects of normal human development. Studies of XO girls, XXY boys, XXX girls, and males with a fragile X chromosome are summarized to demonstrate how results contribute to knowledge about normal cognitive development and about…

  5. Triploidy and other chromosomal abnormalities in a selected line of chickens

    E-print Network

    Paris-Sud XI, Université de

    Triploidy and other chromosomal abnormalities in a selected line of chickens MH Thorne, RK Collins-Auzeville, 10-13 July 1990) triploid / chicken / meiosis / diploid ova Triploidy has been reported in the chicken in both embryos and adults (de Boer et al, 1984). Triploid chick embryos with ZWW sex chromosomes

  6. Undetected sex chromosome aneuploidy by chromosomal microarray.

    PubMed

    Markus-Bustani, Keren; Yaron, Yuval; Goldstein, Myriam; Orr-Urtreger, Avi; Ben-Shachar, Shay

    2012-11-01

    We report on a case of a female fetus found to be mosaic for Turner syndrome (45,X) and trisomy X (47,XXX). Chromosomal microarray analysis (CMA) failed to detect the aneuploidy because of a normal average dosage of the X chromosome. This case represents an unusual instance in which CMA may not detect chromosomal aberrations. Such a possibility should be taken into consideration in similar cases where CMA is used in a clinical setting. PMID:23034780

  7. The tilapias' chromosomes influencing sex determination.

    PubMed

    Cnaani, A

    2013-01-01

    The sex chromosomes of tilapias (family Cichlidae; genera Oreochromis, Sarotherodon and Tilapia) have been studied for over 50 years, which has gained interest from both agricultural and basic scientific perspectives. Several closely related tilapia species which can interbreed have been studied, and it has been repeatedly demonstrated that there is variation within and between species in the chromosomal sex-determination mechanism. Both male and female heterogametic sex-determination systems have been characterized, as well as epistatic and environmental influences on sex determination. Three different linkage groups (LG1, LG3 and LG23) have been identified as sex-associated chromosomes and have been subjected to further cytogenetic research and analyses of the genes located around the sex-determining region. Variation in the genetic and physical characteristics of the sex chromosomes makes tilapias an excellent model system for studying the evolution of vertebrate sex chromosomes. This review summarizes the progress made along 5 decades of research and the current knowledge of the tilapias' sex chromosomes. PMID:24107438

  8. Detection of sex chromosomal aneuploidies XX, Y-Y, and X-Y in human sperm using two-chromosome fluorescence in situ hybridization

    Microsoft Academic Search

    Andrew J. Wyrobek; Wendie A. Robbins; D. Pinkel; H. U. Weier; Y. Mehraein

    1994-01-01

    Sex chromosome aneuploidy is the most common numerical chromosomal abnormality in humans at birth and a substantial portion of these abnormalities involve paternal chromosomes. An efficient method is presented for using air-dried smears of human semen to detect the number of X and Y chromosomes in sperm chromatin using two-chromosome fluorescence in situ hybridization. Air-dried semen smears were pre-treated with

  9. Down's Syndrome and Leukemia: Mechanism of Additional Chromosomal Abnormalities

    ERIC Educational Resources Information Center

    And Others; Goh, Kong-oo

    1978-01-01

    Chromosomal abnormalities, some appearing in a stepwise clonal evoluation, were found in five Down's syndrome patients (35 weeks to 12 years old), four with acute leukemia and one with abnormal regulation of leukopoiesis. (Author/SBH)

  10. The Sex Chromosomes in Evolution and in Medicine

    PubMed Central

    Barr, Murray L.

    1966-01-01

    The recent emergence of human cytogenetics has a firm foundation in studies on other forms of life. Historical highlights are Mendel's studies on the garden pea (published in 1865 but lost in an obscure journal until 1900); formulation of cytogenic postulates by Sutton and Boveri (1902-1903); Bridges' discovery of chromosome abnormalities in Drosophila (1916), followed by numerous similar studies in plants; and demonstration of the chromosomal basis of the syndromes of Down, Klinefelter and Turner in man (1959). The sex chromosomes (XX and XY) evolved from a pair of undifferentiated autosomes of a premammalian ancestor, the X chromosome changing less than the Y as they evolved. Eleven numerical abnormalities of the sex chromosomes are known in man, and knowledge of their effects on development is accumulating. The abnormal complexes range in size from the XO error of Turner's syndrome to the XXXXY error of a variant of Klinefelter's syndrome. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8 PMID:4224254

  11. Sequence of the chicken sex chromosomes

    E-print Network

    Bellott, Daniel Winston

    2010-01-01

    In birds, as in mammals, the chromosome complement determines sex. Male birds are designated ZZ, female ZW. Mammals have the opposite system; males are XY and females XX. Both the avian ZW and mammalian XY pair are believed ...

  12. Sex chromosome aneuploidy in cytogenetic findings of referral patients from south of Iran

    PubMed Central

    Jouyan, Najmeh; Davoudi Dehaghani, Elham; Senemar, Sara; Shojaee, Ashraf; Mozdarani, Hossein

    2012-01-01

    Background: Chromosome abnormality (CA) including Sex chromosomes abnormality (SCAs) is one of the most important causes of disordered sexual development and infertility. SCAs formed by numerical or structural alteration in X and Y chromosomes, are the most frequently CA encountered at both prenatal diagnosis and at birth. Objective: This study describes cytogenetic findings of cases suspected with CA referred for cytogenetic study. Materials and Methods: Blood samples of 4151 patients referred for cytogenetic analysis were cultured for chromosome preparation. Karyotypes were prepared for all samples and G-Banded chromosomes were analyzed using x100 objective lens. Sex chromosome aneuploidy cases were analyzed and categorized in two groups of Turners and Klinefelter’s syndrome (KFS). Results: Out of 230 (5.54%) cases with chromosomally abnormal karyotype, 122 (30%) cases suspected of sexual disorder showed SCA including 46% Turner’s syndrome, 46% KFS and the remaining other sex chromosome abnormalities. The frequency of classic and mosaic form of Turner’s syndrome was 33% and 67%, this was 55% and 45% for KFS, respectively. Conclusion: This study shows a relatively high sex chromosome abnormality in this region and provides cytogenetic data to assist clinicians and genetic counselors to determine the priority of requesting cytogenetic study. Differences between results from various reports can be due to different genetic background or ethnicity. PMID:25242988

  13. Analysis of sex chromosome aneuploidy in sperm from fathers of Turner syndrome patients

    Microsoft Academic Search

    O. Martínez-Pasarell; Carme Nogués; Mercč Bosch; Josep Egozcue; Cristina Templado

    1999-01-01

    Numerical sex chromosome abnormalities were analyzed in sperm from four fathers of Turner syndrome patients of paternal origin\\u000a to determine whether there was an increased frequency of sex chromosome aneuploidy and to elucidate whether meiotic malsegregation\\u000a mechanisms could be involved in the origin of Turner syndrome. Determination of the parental origin of the single X chromosome\\u000a (maternal in all four

  14. Sex chromosomes and sex determination in weird mammals

    Microsoft Academic Search

    J. A. Marshall Graves

    2002-01-01

    Weird mammals are of two types. Highly divergent mammals, such as the marsupials and monotremes, have informed us of the evolutionary history of the Y chromosome and sex-determining gene, and the recently specialized rodents can help us predict its future. The Y chromosome has had a short but eventful history, and is already heading briskly for oblivion. It originated as

  15. Chromosomal abnormalities, meiotic behavior and fertility in domestic animals

    Microsoft Academic Search

    D. A. F. Villagómez; A. Pinton

    2008-01-01

    Since the advent of the surface microspreading technique for synaptonemal complex analysis, increasing interest in describing the synapsis patterns of chromosome abnormalities associated with fertility of domestic animals has been noticed during the past three decades. In spite of the number of scientific reports describing the occurrence of structural chromosome abnormalities, their meiotic behavior and gametic products, little is known

  16. Relationship of Gene Expression and Chromosomal Abnormalities in Colorectal Cancer

    E-print Network

    Stengel, Robert F.

    Relationship of Gene Expression and Chromosomal Abnormalities in Colorectal Cancer Dafna Tsafrir, 1; Departments of 3 Pathology and 4 Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; 5 chromosomal abnormalities in colon cancer. However, the relationships between DNA copy number and gene

  17. Incidental Prenatal Diagnosis of Sex Chromosome Aneuploidies: Health, Behavior, and Fertility

    PubMed Central

    Pieters, J. J. P. M.; Kooper, A. J. A.; van Kessel, A. Geurts; Braat, D. D. M.; Smits, A. P. T.

    2011-01-01

    Objective. To assess the diagnostic relevance of incidental prenatal findings of sex chromosome aneuploidies. Methods. We searched with medical subject headings (MeSHs) and keywords in Medline and the Cochrane Library and systematically screened publications on postnatally diagnosed sex chromosomal aneuploidies from 2006 to 2011 as well as publications on incidentally prenatally diagnosed sex chromosomal aneuploidies from 1980 to 2011. Results. Postnatally diagnosed sex chromosomal aneuploidies demonstrated three clinical relevant domains of abnormality: physical (22–100%), behavior (0–56%), and reproductive health (47–100%), while incidentally prenatally diagnosed sex chromosomal aneuploidies demonstrated, respectively, 0–33%, 0–40%, and 0–36%. Conclusion. In the literature incidental prenatal diagnosis of sex chromosomal aneuploidies is associated with normal to mildly affected phenotypes. This contrasts sharply with those of postnatally diagnosed sex chromosomal aneuploidies and highlights the importance of this ascertainment bias towards the prognostic value of diagnosis of fetal sex chromosomal aneuploidies. This observation should be taken into account, especially when considering excluding the sex chromosomes in invasive prenatal testing using Rapid Aneuploidy Detection. PMID:22191050

  18. Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

    E-print Network

    Shapiro, Mike

    Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae) Joseph A. Ross1,2¤ , James R, United States of America Abstract Diverse sex-chromosome systems are found in vertebrates, particularly been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex

  19. Sex chromosome evolution in moths and butterflies.

    PubMed

    Sahara, Ken; Yoshido, Atsuo; Traut, Walther

    2012-01-01

    Lepidoptera, i.e. moths and butterflies, have a female heterogametic sex chromosome system, with most females having a WZ constitution while males are ZZ. Besides this predominant WZ/ZZ system, Z/ZZ, WZ(1)Z(2)/Z(1)Z(1)Z(2)Z(2) and W(1)W(2)Z/ZZ systems also occur. Sex is determined by an unknown W-linked gene or genes in Bombyx mori, but by dosage-dependent and equally unknown Z-linked genes in all Z/ZZ species. The female heterogametic sex chromosome system has been conserved for at least 180 MY in the phylogenetic branch that combines Lepidoptera and Trichoptera. The W chromosome, which is present in most lepidopteran species, was incorporated in the sex chromosome system much later, about 90-100 MY ago. The Z chromosomes are highly conserved among Lepidoptera, much like the Z in birds or the X in mammals. The W, on the other hand, is evolving rapidly. It is crammed with repetitive elements which appear to have a high turnover rate but poor in or even devoid of protein-coding genes. It has frequently undergone fusion with autosomes or sporadically lost altogether. PMID:22187366

  20. Neo-sex chromosome inheritance across species in Silene hybrids.

    PubMed

    Weingartner, L A; Delph, L F

    2014-07-01

    Neo-sex chromosomes, which form through the major restructuring of ancestral sex chromosome systems, have evolved in various taxa. Such restructuring often consists of the fusion of an autosome to an existing sex chromosome, resulting in novel sex chromosome formations (e.g. X1X2Y or XY1Y2.). Comparative studies are often made between restructured sex chromosome systems of closely related species, and here we evaluate the consequences of variable sex chromosome systems to hybrids. If neo-sex chromosomes are improperly inherited across species, this could lead to aberrant development and reproductive isolation. In this study, we examine the fate of neo-sex chromosomes in hybrids of the flowering plants Silene diclinis and Silene latifolia. Silene diclinis has a neo-sex chromosome system (XY1Y2) that is thought to have evolved from an ancestral XY system that is still present in S. latifolia. These species do not hybridize naturally, and improper sex chromosome inheritance could contribute to reproductive isolation. We investigated whether this major restructuring of sex chromosomes prevents their proper inheritance in a variety of hybrid crosses, including some F2 - and later-generation hybrids, with sex chromosome-linked, species-specific, polymorphic markers and chromosome squashes. We discovered that despite the differences in sex chromosomes that exist between these two species, proper segregation had occurred in hybrids that made it to flowering, including later-generation hybrids, indicating that neo-sex chromosome formation alone does not result in complete reproductive isolation between these two species. Additionally, hybrids with aberrant sex expression (e.g. neuter, hermaphrodite) also inherited the restructured sex chromosomes properly, highlighting that issues with sexual development in hybrids can be caused by intrinsic genetic incompatibility rather than improper sex chromosome inheritance. PMID:24739043

  1. Meiosis and sex chromosome aneuploidy: how meiotic errors cause aneuploidy; how aneuploidy causes meiotic errors.

    PubMed

    Hall, Heather; Hunt, Patricia; Hassold, Terry

    2006-06-01

    As a group, sex chromosome aneuploidies - the 47,XXY, 47,XYY, 47,XXX and 45,X conditions - constitute the most common class of chromosome abnormality in human live-births. Considerable attention has been given to the somatic abnormalities associated with these conditions, but less is known about their meiotic phenotypes; that is, how does sex chromosome imbalance influence the meiotic process. This has become more important with the advent of assisted reproductive technologies, because individuals previously thought to be infertile can now become biological parents. Indeed, there are several recent reports of successful pregnancies involving 47,XXY fathers, and suggestions that cryopreservation of ovarian tissue might impart fertility to at least some Turner syndrome individuals. Thus, the possible consequences of sex chromosome aneuploidy on meiotic chromosome segregation need to be explored. PMID:16647844

  2. Avian sex chromosomes: dosage compensation matters. 

    E-print Network

    McQueen, Heather A; Clinton, Michael

    2009-01-01

    of such dosage compensated genes can be found on the short arm of the Z chromosome. The implications of this new picture of avian dosage compensation for avian sex determination are discussed, along with a possible mechanism of avian dosage compensation....

  3. Psychoeducational Implications of Sex Chromosome Anomalies

    ERIC Educational Resources Information Center

    Wodrich, David L.; Tarbox, Jennifer

    2008-01-01

    Numerous anomalies involving the sex chromosomes (X or Y) have been documented and their impact on development, learning, and behavior studied. This article reviews three of these disorders, Turner syndrome, Klinefelter syndrome, and Lesch-Nyhan disease. Each of these three is associated with one or more selective impairments or behavioral…

  4. Plant sex chromosomes: molecular structure and function.

    PubMed

    Jamilena, M; Mariotti, B; Manzano, S

    2008-01-01

    Recent molecular and genomic studies carried out in a number of model dioecious plant species, including Asparagus officinalis, Carica papaya, Silene latifolia, Rumex acetosa and Marchantia polymorpha, have shed light on the molecular structure of both homomorphic and heteromorphic sex chromosomes, and also on the gene functions they have maintained since their evolution from a pair of autosomes. The molecular structure of sex chromosomes in species from different plant families represents the evolutionary pathway followed by sex chromosomes during their evolution. The degree of Y chromosome degeneration that accompanies the suppression of recombination between the Xs and Ys differs among species. The primitive Ys of A. officinalis and C. papaya have only diverged from their homomorphic Xs in a short male-specific and non-recombining region (MSY), while the heteromorphic Ys of S. latifolia, R. acetosa and M. polymorpha have diverged from their respective Xs. As in the Y chromosomes of mammals and Drosophila, the accumulation of repetitive DNA, including both transposable elements and satellite DNA, has played an important role in the divergence and size enlargement of plant Ys, and consequently in reducing gene density. Nevertheless, the degeneration process in plants does not appear to have reached the Y-linked genes. Although a low gene density has been found in the sequenced Y chromosome of M. polymorpha, most of its genes are essential and are expressed in the vegetative and reproductive organs in both male and females. Similarly, most of the Y-linked genes that have been isolated and characterized up to now in S. latifolia are housekeeping genes that have X-linked homologues, and are therefore expressed in both males and females. Only one of them seems to be degenerate with respect to its homologous region in the X. Sequence analysis of larger regions in the homomorphic X and Y chromosomes of papaya and asparagus, and also in the heteromorphic sex chromosomes of S. latifolia and R. acetosa, will reveal the degenerative changes that the Y-linked gene functions have experienced during sex chromosome evolution. PMID:18504355

  5. Trisomy 13: A New Recurring Chromosome Abnormality in Acute Leukemia

    Microsoft Academic Search

    Hartmut Dohner; Diane C. Arthur; Edward D. Ball; Robert E. Sobol; Frederick R. Davey; David Lawrence; Lawrence Gordon; Shivanand R. Patil; Rawatmal B. Surana; Joseph R. Testa; Ram S. Verma; Charles A. Schiffer; Doris H. Wurster-Hill; Clara D. Bloomfield

    1990-01-01

    A new recurring chromosome abnormality was identified in 8 of 621 consecutive successfully karyotyped adults with de novo acute leukemia. These eight patients had trisomy 13 as the sole cytogenetic abnormality. On central morpho- logic review, five cases were classified as subtypes of acute myeloid leukemia, one as acute mixed lymphoid and my- eloid leukemia, one as acute lymphoid leukemia,

  6. Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

    Microsoft Academic Search

    Joseph A. Ross; James R. Urton; Jessica Boland; Michael D. Shapiro; Catherine L. Peichel

    2009-01-01

    Diverse sex-chromosome systems are found in vertebrates, particularly in teleost fishes, where different systems can be found in closely related species. Several mechanisms have been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex-determination gene, the appearance of a new sex-determination gene on an autosome, and fusions between sex chromosomes and autosomes. To better

  7. The role of chromosome abnormalities in reproductive failure

    E-print Network

    Boyer, Edmond

    '(=tude de la Fertilité; Paris, 19-21 octobre 1989) Summary ― The frequency of chromosome trisomies determined using molecular probes are presented and the proportion of sperm and eggs that are nullisomic or disomic for a sex chromo- some or an autosome 16, 18 or 21 is calculated. chromosome

  8. Signatures of Sex-Antagonistic Selection on Recombining Sex Chromosomes

    PubMed Central

    Kirkpatrick, Mark; Guerrero, Rafael F.

    2014-01-01

    Sex-antagonistic (SA) selection has major evolutionary consequences: it can drive genomic change, constrain adaptation, and maintain genetic variation for fitness. The recombining (or pseudoautosomal) regions of sex chromosomes are a promising setting in which to study SA selection because they tend to accumulate SA polymorphisms and because recombination allows us to deploy the tools of molecular evolution to locate targets of SA selection and quantify evolutionary forces. Here we use coalescent models to characterize the patterns of polymorphism expected within and divergence between recombining X and Y (or Z and W) sex chromosomes. SA selection generates peaks of divergence between X and Y that can extend substantial distances away from the targets of selection. Linkage disequilibrium between neutral sites is also inflated. We show how the pattern of divergence is altered when the SA polymorphism or the sex-determining region was recently established. We use data from the flowering plant Silene latifolia to illustrate how the strength of SA selection might be quantified using molecular data from recombining sex chromosomes. PMID:24578352

  9. Signatures of sex-antagonistic selection on recombining sex chromosomes.

    PubMed

    Kirkpatrick, Mark; Guerrero, Rafael F

    2014-06-01

    Sex-antagonistic (SA) selection has major evolutionary consequences: it can drive genomic change, constrain adaptation, and maintain genetic variation for fitness. The recombining (or pseudoautosomal) regions of sex chromosomes are a promising setting in which to study SA selection because they tend to accumulate SA polymorphisms and because recombination allows us to deploy the tools of molecular evolution to locate targets of SA selection and quantify evolutionary forces. Here we use coalescent models to characterize the patterns of polymorphism expected within and divergence between recombining X and Y (or Z and W) sex chromosomes. SA selection generates peaks of divergence between X and Y that can extend substantial distances away from the targets of selection. Linkage disequilibrium between neutral sites is also inflated. We show how the pattern of divergence is altered when the SA polymorphism or the sex-determining region was recently established. We use data from the flowering plant Silene latifolia to illustrate how the strength of SA selection might be quantified using molecular data from recombining sex chromosomes. PMID:24578352

  10. A primitive Y chromosome in papaya marks incipient sex chromosome evolution

    Microsoft Academic Search

    Zhiyong Liu; Paul H. Moore; Hao Ma; Christine M. Ackerman; Makandar Ragiba; Qingyi Yu; Heather M. Pearl; Minna S. Kim; Joseph W. Charlton; John I. Stiles; Francis T. Zee; Andrew H. Paterson; Ray Ming

    2004-01-01

    Many diverse systems for sex determination have evolved in plants and animals. One involves physically distinct (heteromorphic) sex chromosomes (X and Y, or Z and W) that are homozygous in one sex (usually female) and heterozygous in the other (usually male). Sex chromosome evolution is thought to involve suppression of recombination around the sex determination genes, rendering permanently heterozygous a

  11. On the origin of sex chromosomes from meiotic drive.

    PubMed

    Úbeda, Francisco; Patten, Manus M; Wild, Geoff

    2015-01-01

    Most animals and many plants make use of specialized chromosomes (sex chromosomes) to determine an individual's sex. Best known are the XY and ZW sex-determination systems. Despite having evolved numerous times, sex chromosomes present something of an evolutionary puzzle. At their origin, alleles that dictate development as one sex or the other (primitive sex chromosomes) face a selective penalty, as they will be found more often in the more abundant sex. How is it possible that primitive sex chromosomes overcome this disadvantage? Any theory for the origin of sex chromosomes must identify the benefit that outweighs this cost and enables a sex-determining mutation to establish in the population. Here we show that a new sex-determining allele succeeds when linked to a sex-specific meiotic driver. The new sex-determining allele benefits from confining the driving allele to the sex in which it gains the benefit of drive. Our model requires few special assumptions and is sufficiently general to apply to the evolution of sex chromosomes in outbreeding cosexual or dioecious species. We highlight predictions of the model that can discriminate between this and previous theories of sex-chromosome origins. PMID:25392470

  12. Detection of chromosomal abnormalities in human sperm

    SciTech Connect

    Brandriff, B.; Gordon, L.; Ashworth, A.K.; Watchmaker, G.; Carrano, A.V.

    1985-06-19

    A new technology developed by Rudak, et al. for examining the chromosomal constitution of human sperm through fusion with eggs from the Syrian hamster was used to obtain baseline data on the types and frequencies of aberrations in sperm of normal men. The frequency of structural aberrations in 2724 sperm chromosome karyotypes from the 13 healthy non-exposed donors ranged from 2 to 15.8%, demonstrating significant interindividual variability. The most frequently occurring aberrations were chromosome breaks, followed by acentric fragments, chromatid exchanges, chromatid breaks, dicentrics and translocations, chromosome deletions and duplications, inversions, and chromatid deletions. Two donors previously reported had one cell each with multiple chromatid exchanges and breaks. In addition, the oldest donor, AA, had 5 cells out of 124 examined with multiple breaks and rearrangements too extensive to completely identify. 17 refs., 2 tabs.

  13. The role of chromosomal rearrangements in the evolution of Silene latifolia sex chromosomes

    Microsoft Academic Search

    Roman Hobza; Eduard Kejnovsky; Boris Vyskot; Alex Widmer

    2007-01-01

    Silene latifolia is a model plant for studies of the early steps of sex chromosome evolution. In comparison to mammalian sex chromosomes that\\u000a evolved 300 mya, sex chromosomes of S. latifolia appeared approximately 20 mya. Here, we combine results from physical mapping of sex-linked genes using polymerase chain\\u000a reaction on microdissected arms of the S. latifolia X chromosome, and fluorescence in situ

  14. Sex-biased gene expression at homomorphic sex chromosomes in emus and its implication for

    E-print Network

    Nachman, Michael

    Sex-biased gene expression at homomorphic sex chromosomes in emus and its implication for sex York, NY, and approved March 8, 2013 (received for review October 1, 2012) Sex chromosomes originate for a loss of recombination and sets in motion the evolutionary processes generating heteromorphic sex

  15. Learning disorders and sex chromosome aberrations.

    PubMed

    Hier, D B; Atkins, L; Perlo, V P

    1980-03-01

    No sex chromosome aberrations were detected in a prospective study of twenty adult dyslexic men. A retrospective study of eighty-nine subjects with known sex chromosome aberrations revealed twenty of them to be mentally-retarded. Among the sixty-nine subjects of normal intelligence, learning, speech and attention disorders were frequent. Children with 47,XYY, 47,XXY, and 47,XXX karyotypes appeared particularly prone to experience delays in speech development as well as later academic underachievement in language-related subjects. In contrast, speech development was normal in all of the girls with Turner's syndrome and later academic difficulties were usually confined to mathematics or science. Hyperactivity was noted with considerable frequency among 47,XYY and Turner's syndrome subjects, but not among subjects with a 47,XXX or 47,XXY karyotype. PMID:7381931

  16. Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

    PubMed Central

    Ross, Joseph A.; Urton, James R.; Boland, Jessica; Shapiro, Michael D.; Peichel, Catherine L.

    2009-01-01

    Diverse sex-chromosome systems are found in vertebrates, particularly in teleost fishes, where different systems can be found in closely related species. Several mechanisms have been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex-determination gene, the appearance of a new sex-determination gene on an autosome, and fusions between sex chromosomes and autosomes. To better understand these evolutionary transitions, a detailed comparison of sex chromosomes between closely related species is essential. Here, we used genetic mapping and molecular cytogenetics to characterize the sex-chromosome systems of multiple stickleback species (Gasterosteidae). Previously, we demonstrated that male threespine stickleback fish (Gasterosteus aculeatus) have a heteromorphic XY pair corresponding to linkage group (LG) 19. In this study, we found that the ninespine stickleback (Pungitius pungitius) has a heteromorphic XY pair corresponding to LG12. In black-spotted stickleback (G. wheatlandi) males, one copy of LG12 has fused to the LG19-derived Y chromosome, giving rise to an X1X2Y sex-determination system. In contrast, neither LG12 nor LG19 is linked to sex in two other species: the brook stickleback (Culaea inconstans) and the fourspine stickleback (Apeltes quadracus). However, we confirmed the existence of a previously reported heteromorphic ZW sex-chromosome pair in the fourspine stickleback. The sex-chromosome diversity that we have uncovered in sticklebacks provides a rich comparative resource for understanding the mechanisms that underlie the rapid turnover of sex-chromosome systems. PMID:19229325

  17. Turnover of sex chromosomes in the stickleback fishes (gasterosteidae).

    PubMed

    Ross, Joseph A; Urton, James R; Boland, Jessica; Shapiro, Michael D; Peichel, Catherine L

    2009-02-01

    Diverse sex-chromosome systems are found in vertebrates, particularly in teleost fishes, where different systems can be found in closely related species. Several mechanisms have been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex-determination gene, the appearance of a new sex-determination gene on an autosome, and fusions between sex chromosomes and autosomes. To better understand these evolutionary transitions, a detailed comparison of sex chromosomes between closely related species is essential. Here, we used genetic mapping and molecular cytogenetics to characterize the sex-chromosome systems of multiple stickleback species (Gasterosteidae). Previously, we demonstrated that male threespine stickleback fish (Gasterosteus aculeatus) have a heteromorphic XY pair corresponding to linkage group (LG) 19. In this study, we found that the ninespine stickleback (Pungitius pungitius) has a heteromorphic XY pair corresponding to LG12. In black-spotted stickleback (G. wheatlandi) males, one copy of LG12 has fused to the LG19-derived Y chromosome, giving rise to an X(1)X(2)Y sex-determination system. In contrast, neither LG12 nor LG19 is linked to sex in two other species: the brook stickleback (Culaea inconstans) and the fourspine stickleback (Apeltes quadracus). However, we confirmed the existence of a previously reported heteromorphic ZW sex-chromosome pair in the fourspine stickleback. The sex-chromosome diversity that we have uncovered in sticklebacks provides a rich comparative resource for understanding the mechanisms that underlie the rapid turnover of sex-chromosome systems. PMID:19229325

  18. Molecular cytogenetic studies in structural abnormalities of chromosome 13

    SciTech Connect

    Lozzio, C.B.; Bamberger, E.; Anderson, I. [Univ. of Tennessee, Knoxville, TN (United States)] [and others

    1994-09-01

    A partial trisomy 13 was detected prenatally in an amniocentesis performed due to the following ultrasound abnormalities: open sacral neural tube defect (NTD), a flattened cerebellum, and lumbar/thoracic hemivertebrae. Elevated AFP and positive acetylcholinesterase in amniotic fluid confirmed the open NTD. Chromosome analysis showed an extra acrocentric chromosome marker. FISH analysis with the painting probe 13 showed that most of the marker was derived from this chromosome. Chromosomes on the parents revealed that the mother had a balanced reciprocal translocation t(2;13)(q23;q21). Dual labeling with painting chromosomes 2 and 13 on cells from the mother and from the amniotic fluid identified the marker as a der(13)t(2;13)(p23;q21). Thus, the fetus had a partial trisomy 13 and a small partial trisomy 2p. The maternal grandfather was found to be a carrier for this translocation. Fetal demise occurred a 29 weeks of gestation. The fetus had open lumbar NTD and showed dysmorphic features, overlapping fingers and imperforate anus. This woman had a subsequent pregnancy and chorionic villi sample showed that this fetus was normal. Another case with an abnormal chromosome 13 was a newborn with partial monosomy 13 due to the presence of a ring chromosome 13. This infant had severe intrauterine growth retardation, oligohydramnios, dysmorphic features and multiple congenital microphthalmia, congenital heart disease, absent thumbs and toes and cervical vertebral anomalies. Chromosome studies in blood and skin fibroblast cultures showed that one chromosome 3 was replaced by a ring chromosome of various sizes. This ring was confirmed to be derived from chromosome 13 using the centromeric 21/13 probe.

  19. Detection of sex chromosomal aneuploidies X-X, Y-Y, and X-Y in human sperm using two-chromosome fluorescence in situ hybridization

    SciTech Connect

    Wyrobek, A.J. [Lawrence Livermore National Lab., CA (United States); Robbins, W.A. [Lawrence Livermore National Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States); Pinkel, D.; Weier, H.U. [Univ. of California, San Francisco, CA (United States); Mehraein, Y. [Univ. of California, San Francisco, CA (United States)]|[Philipps Universitat, Marburg (Germany)

    1994-10-15

    Sex chromosome aneuploidy is the most common numerical chromosomal abnormality in humans at birth and a substantial portion of these abnormalities involve paternal chromosomes. An efficient method is presented for using air-dried smears of human semen to detect the number of X and Y chromosomes in sperm chromatin using two-chromosome fluorescence in situ hybridization. Air-dried semen smears were pre-treated with dithiothreitol and 3,4-diiodosalicylate salt to decondense the sperm chromatin and then were hybridized with repetitive sequence DNA probes that had been generated by PCR and differentially labeled. Hybridizations with X and Y specific probes showed the expected ratio of 50%X:50%Y bearing sperm. Sperm carrying extra fluorescence domains representing disomy for the X or Y chromosomes occurred at frequencies of {approximately} 4 per 10,000 sperm each. Cells carrying both X and Y fluorescence domains occurred at a frequency of {approximately} 6/10,000. Thus, the overall frequency of sperm that carried an extra sex chromosome was 1.4/1,000. The frequencies of sperm carrying sex chromosome aneuploidies determined by hybridization did not differ statistically from those reported from the same laboratory using the human-sperm/hamster-egg cytogenetic technique. Multi-chromosome fluorescence in situ hybridization to sperm is a promising method for assessing sex-ratio alterations in human semen and for determining the fraction of sperm carrying sex or other chromosome aneuploidies which may be transmissible to offspring. 44 refs., 1 fig., 3 tabs.

  20. Sex Chromosome Complement Affects Nociception and Analgesia in Newborn Mice

    E-print Network

    Sandini, Giulio

    Sex Chromosome Complement Affects Nociception and Analgesia in Newborn Mice Laura Gioiosa, Xuqi, whereas males are often more sensitive to analgesia induced by -agonists. Sex differences are found even the contribution of the direct action of sex chromosome genes in hotplate and tail withdrawal tests. We used the 4

  1. Chromosomal abnormalities and tumor development: from genes to therapeutic mechanisms.

    PubMed

    Cobaleda, C; Pérez-Losada, J; Sánchez-García, I

    1998-11-01

    This article highlights the recent advances in our understanding of the molecular structure and function of proteins that are activated or created by chromosomal abnormalities and discusses their possible role in tumor development. The molecular characterization of these proteins has revealed that tumor-specific fusion proteins are the consequence of the majority of chromosomal translocations associated with leukemias and solid tumors. A common theme that emerges is that creation of these proteins disrupts the normal development of tumor-specific target cells by blocking apoptosis. These insights identify these chromosomal translocation-associated genes as potential targets for improved cancer therapies. PMID:9872058

  2. NIH scientists visualize how cancer chromosome abnormalities form in living cells

    Cancer.gov

    For the first time, scientists have directly observed events that lead to the formation of a chromosome abnormality that is often found in cancer cells. The abnormality, called a translocation, occurs when part of a chromosome breaks off and becomes attached to another chromosome. A chromosome translocation is visualized with images within circles indicating chromosome breaks.

  3. Conserved sex chromosomes across adaptively radiated Anolis lizards.

    PubMed

    Rovatsos, Michail; Altmanová, Marie; Pokorná, Martina; Kratochvíl, Lukáš

    2014-07-01

    Vertebrates possess diverse sex-determining systems, which differ in evolutionary stability among particular groups. It has been suggested that poikilotherms possess more frequent turnovers of sex chromosomes than homoiotherms, whose effective thermoregulation can prevent the emergence of the sex reversals induced by environmental temperature. Squamate reptiles used to be regarded as a group with an extensive variability in sex determination; however, we document how the rather old radiation of lizards from the genus Anolis, known for exceptional ecomorphological variability, was connected with stability in sex chromosomes. We found that 18 tested species, representing most of the phylogenetic diversity of the genus, share the gene content of their X chromosomes. Furthermore, we discovered homologous sex chromosomes in species of two genera (Sceloporus and Petrosaurus) from the family Phrynosomatidae, serving here as an outgroup to Anolis. We can conclude that the origin of sex chromosomes within iguanas largely predates the Anolis radiation and that the sex chromosomes of iguanas remained conserved for a significant part of their evolutionary history. Next to therian mammals and birds, Anolis lizards therefore represent another adaptively radiated amniote clade with conserved sex chromosomes. We argue that the evolutionary stability of sex-determining systems may reflect an advanced stage of differentiation of sex chromosomes rather than thermoregulation strategy. PMID:24433436

  4. A neo-sex-chromosome that drives post-zygotic sex determiniation in the Hessian fly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two nonoverlapping autosomal inversions defined unusual neo-sex chromosomes in the Hessian fly (Mayetiola destructor). Like other neo-sex chromosomes, these were normally heterozygous, present only in one sex, and suppressed recombination around a sex-determining master switch. Their unusual propert...

  5. Comparative analysis of sex chromosomes in Leporinus species (Teleostei, Characiformes) using chromosome painting

    PubMed Central

    2013-01-01

    Background The Leporinus genus, belonging to the Anostomidae family, is an interesting model for studies of sex chromosome evolution in fish, particularly because of the presence of heteromorphic sex chromosomes only in some species of the genus. In this study we used W chromosome-derived probes in a series of cross species chromosome painting experiments to try to understand events of sex chromosome evolution in this family. Results W chromosome painting probes from Leporinus elongatus, L. macrocephalus and L. obtusidens were hybridized to each others chromosomes. The results showed signals along their W chromosomes and the use of L. elongatus W probe against L. macrocephalus and L. obtusidens also showed signals over the Z chromosome. No signals were observed when the later aforementioned probe was used in hybridization procedures against other four Anostomidae species without sex chromosomes. Conclusions Our results demonstrate a common origin of sex chromosomes in L. elongatus, L. macrocephalus and L. obtusidens but suggest that the L. elongatus chromosome system is at a different evolutionary stage. The absence of signals in the species without differentiated sex chromosomes does not exclude the possibility of cryptic sex chromosomes, but they must contain other Leporinus W sequences than those described here. PMID:23822802

  6. Relationship of Gene Expression and Chromosomal Abnormalities in Colorectal Cancer

    Microsoft Academic Search

    Dafna Tsafrir; Manny Bacolod; Zachariah Selvanayagam; Ilan Tsafrir; Jinru Shia; Zhaoshi Zeng; Hao Liu; Robert F. Stengel; Francis Barany; William L. Gerald; Philip B. Paty; Eytan Domany; Daniel A. Notterman

    Several studies have verified the existence of multiple chromosomal abnormalities in colon cancer. However, the relationships between DNA copy number and gene expression have not been adequately explored nor globally monitored during the progression of the disease. In this work, three types of array-generated data (expression, single nucleotide poly- morphism, and comparative genomic hybridization) were collected from a large set

  7. Sex chromosomes and sex determination in weird mammals.

    PubMed

    Marshall Graves, J A

    2002-01-01

    Weird mammals are of two types. Highly divergent mammals, such as the marsupials and monotremes, have informed us of the evolutionary history of the Y chromosome and sex-determining gene, and the recently specialized rodents can help us predict its future. The Y chromosome has had a short but eventful history, and is already heading briskly for oblivion. It originated as a homologous partner of the X when it acquired a sex-determining gene (not necessarily SRY). Most of the genes on the Y, even those with a male-specific function, evolved from genes now on the X. At the mercy of a high rate of variability and the forces of drift and selection, the Y has lost genes at a rate of 3-6 genes/million years, sparing those that acquired critical male-specific functions. Even these genes have disappeared from one mammalian lineage or another as their functions were usurped by genes elsewhere in the genome. The mammalian testis-determining gene, SRY, is a typical Y-borne gene. It arose by truncation of a gene (SOX3) on the X that is expressed in brain development, and it may work by interacting with (inhibiting?) related genes, including SOX9. Variant sex-determining systems in rodents show that the action of SRY can change, as it evidently has in the mouse, and SRY can be inactivated, as in akodont rodents, or even completely superseded, as in mole voles. PMID:12438793

  8. Mechanisms and consequences of paternally transmitted chromosomal abnormalities

    SciTech Connect

    Marchetti, F; Wyrobek, A J

    2005-04-05

    Paternally transmitted chromosomal damage has been associated with pregnancy loss, developmental and morphological defects, infant mortality, infertility, and genetic diseases in the offspring including cancer. There is epidemiological evidence linking paternal exposure to occupational or environmental agents with an increased risk of abnormal reproductive outcomes. There is also a large body of literature on germ cell mutagenesis in rodents showing that treatment of male germ cells with mutagens has dramatic consequences on reproduction producing effects such as those observed in human epidemiological studies. However, we know very little about the etiology, transmission and early embryonic consequences of paternally-derived chromosomal abnormalities. The available evidence suggests that: (1) there are distinct patterns of germ cell-stage differences in the sensitivity of induction of transmissible genetic damage with male postmeiotic cells being the most sensitive; (2) cytogenetic abnormalities at first metaphase after fertilization are critical intermediates between paternal exposure and abnormal reproductive outcomes; and, (3) there are maternally susceptibility factors that may have profound effects on the amount of sperm DNA damage that is converted into chromosomal aberrations in the zygote and directly affect the risk for abnormal reproductive outcomes.

  9. Analysis of non-disjunction in sex chromosome tetrasomy and pentasomy

    Microsoft Academic Search

    Terry Hassold; Dorothy Pettay; Kristin May; Arthur Robinson

    1990-01-01

    X-linked DNA markers were used to determine the parental origin of the additional sex chromosomes in eight individuals with sex chromosome tetrasomy or pentasomy. In all cases studied, one parent contributed a single sex chromosome while the other parent contributed three or four sex chromosomes. Thus, it seems likely that most, if not all, sex chromosome tetrasomy and pentasomy is

  10. Effects of sex chromosome dosage on corpus callosum morphology in supernumerary sex chromosome aneuploidies

    PubMed Central

    2014-01-01

    Background Supernumerary sex chromosome aneuploidies (sSCA) are characterized by the presence of one or more additional sex chromosomes in an individual’s karyotype; they affect around 1 in 400 individuals. Although there is high variability, each sSCA subtype has a characteristic set of cognitive and physical phenotypes. Here, we investigated the differences in the morphometry of the human corpus callosum (CC) between sex-matched controls 46,XY (N =99), 46,XX (N =93), and six unique sSCA karyotypes: 47,XYY (N =29), 47,XXY (N =58), 48,XXYY (N =20), 47,XXX (N =30), 48,XXXY (N =5), and 49,XXXXY (N =6). Methods We investigated CC morphometry using local and global area, local curvature of the CC boundary, and between-landmark distance analysis (BLDA). We hypothesized that CC morphometry would vary differentially along a proposed spectrum of Y:X chromosome ratio with supernumerary Y karyotypes having the largest CC areas and supernumerary X karyotypes having significantly smaller CC areas. To investigate this, we defined an sSCA spectrum based on a descending Y:X karyotype ratio: 47,XYY, 46,XY, 48,XXYY, 47,XXY, 48,XXXY, 49,XXXXY, 46,XX, 47,XXX. We similarly explored the effects of both X and Y chromosome numbers within sex. Results of shape-based metrics were analyzed using permutation tests consisting of 5,000 iterations. Results Several subregional areas, local curvature, and BLDs differed between groups. Moderate associations were found between area and curvature in relation to the spectrum and X and Y chromosome counts. BLD was strongly associated with X chromosome count in both male and female groups. Conclusions Our results suggest that X- and Y-linked genes have differential effects on CC morphometry. To our knowledge, this is the first study to compare CC morphometry across these extremely rare groups. PMID:25780557

  11. Developmental ability of chromosomally abnormal human embryos to develop to the blastocyst stage

    Microsoft Academic Search

    M. Sandalinas; S. Sadowy; M. Alikani; G. Calderon; J. Cohen

    2001-01-01

    BACKGROUND: A correlation between morphology, developmental competence and chromosome abnormalities is established. However, since absolute correlations are rare, embryo selection remains one of the most arduous tasks in assisted reproduction. This study was undertaken in order to determine which chromosomal abnormalities are compatible with development to the blastocyst stage. METHODS: Embryos diagnosed by preimplantation genetic diagnosis (PGD) as chromosomally abnormal

  12. Chromosomal painting and ZW sex chromosomes differentiation in Characidium (Characiformes, Crenuchidae)

    PubMed Central

    2011-01-01

    Background The Characidium (a Neotropical fish group) have a conserved diploid number (2n = 50), but show remarkable differences among species and populations in relation to sex chromosome systems and location of nucleolus organizer regions (NOR). In this study, we isolated a W-specific probe for the Characidium and characterized six Characidium species/populations using cytogenetic procedures. We analyzed the origin and differentiation of sex and NOR-bearing chromosomes by chromosome painting in populations of Characidium to reveal their evolution, phylogeny, and biogeography. Results A W-specific probe for efficient chromosome painting was isolated by microdissection and degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR) amplification of W chromosomes from C. gomesi. The W probe generated weak signals dispersed on the proto sex chromosomes in C. zebra, dispersed signals in both W and Z chromosomes in C. lauroi and, in C. gomesi populations revealed a proximal site on the long arms of the Z chromosome and the entire W chromosome. All populations showed small terminal W probe sites in some autosomes. The 18S rDNA revealed distinctive patterns for each analyzed species/population with regard to proto sex chromosome, sex chromosome pair, and autosome location. Conclusions The results from dual-color fluorescence in situ hybridization (dual-color FISH) using W and 18S rDNA probes allowed us to infer the putative evolutionary pathways for the differentiation of sex chromosomes and NORs, from structural rearrangements in a sex proto-chromosome, followed by gene erosion and heterochromatin amplification, morphological differentiation of the sex chromosomal pair, and NOR transposition, giving rise to the distinctive patterns observed among species/populations of Characidium. Biogeographic isolation and differentiation of sex chromosomes seem to have played a major role in the speciation process in this group of fish. PMID:21787398

  13. How mammalian sex chromosomes acquired their peculiar gene content

    Microsoft Academic Search

    Eric J. Vallender; Bruce T. Lahn

    2004-01-01

    Summary It has become increasingly evident that gene content of the sex chromosomes is markedly different from that of the autosomes. Both sex chromosomes appear enriched for genes related to sexual differentiation and reproduc- tion;butcuriously,thehumanXchromosomealsoseems to bear a preponderance of genes linked to brain and muscle functions. In this review, we will synthesize several evolutionary theories that may account for

  14. Identification of sex chromosomes in lake trout (Salvelinus namaycush)

    Microsoft Academic Search

    R. B. Phillips; P. E. Ihssen

    1985-01-01

    In the male trout there is a difference in the quinacrine banding and C-banding patterns between the two homologs of the second largest chromosome pair. This chromosome is the only large submetacentric in the karyotype, making it easy to identify and suggesting that the sex chromosomes have become differentiated since the time of tetraploidization. In males one homolog has a

  15. Fetal Facial Defects: Associated Malformations and Chromosomal Abnormalities

    Microsoft Academic Search

    K. H. Nicolaides; D. R. Salvesen; R. J. M. Snijders; C. M. Gosden

    1993-01-01

    During an 8-year period, facial defects were observed in 146 (7%) of the 2,086 fetuses that underwent karyotyping in our unit because of fetal malformations and\\/or growth retardation. Chromosomal abnormalities were detected in 37 of 56 (66%) fetuses with micrognathia, in 10 of 13 (77%) with macroglossia, in 31 of 64 (48 %) with cleft lip and palate, in 5

  16. Sex chromosomes: evolution of the weird and wonderful.

    PubMed

    Charlesworth, Deborah; Charlesworth, Brian

    2005-02-22

    New findings in the platypus and Drosophila pseudoobscura illustrate, yet again, that the sex chromosomes seem never to stop evolving. Degeneration processes lead to a continual loss of genes and gene activity on the Y chromosome, and complete loss of Y-linked genes is possible if autosomal genes take over control of male fertility - though addition of new material to the sex chromosomes may start the process anew. PMID:15723783

  17. Relationship of gene expression and chromosomal abnormalities in colorectal cancer.

    PubMed

    Tsafrir, Dafna; Bacolod, Manny; Selvanayagam, Zachariah; Tsafrir, Ilan; Shia, Jinru; Zeng, Zhaoshi; Liu, Hao; Krier, Curtis; Stengel, Robert F; Barany, Francis; Gerald, William L; Paty, Philip B; Domany, Eytan; Notterman, Daniel A

    2006-02-15

    Several studies have verified the existence of multiple chromosomal abnormalities in colon cancer. However, the relationships between DNA copy number and gene expression have not been adequately explored nor globally monitored during the progression of the disease. In this work, three types of array-generated data (expression, single nucleotide polymorphism, and comparative genomic hybridization) were collected from a large set of colon cancer patients at various stages of the disease. Probes were annotated to specific chromosomal locations and coordinated alterations in DNA copy number and transcription levels were revealed at specific positions. We show that across many large regions of the genome, changes in expression level are correlated with alterations in DNA content. Often, large chromosomal segments, containing multiple genes, are transcriptionally affected in a coordinated way, and we show that the underlying mechanism is a corresponding change in DNA content. This implies that whereas specific chromosomal abnormalities may arise stochastically, the associated changes in expression of some or all of the affected genes are responsible for selecting cells bearing these abnormalities for clonal expansion. Indeed, particular chromosomal regions are frequently gained and overexpressed (e.g., 7p, 8q, 13q, and 20q) or lost and underexpressed (e.g., 1p, 4, 5q, 8p, 14q, 15q, and 18) in primary colon tumors, making it likely that these changes favor tumorigenicity. Furthermore, we show that these aberrations are absent in normal colon mucosa, appear in benign adenomas (albeit only in a small fraction of the samples), become more frequent as disease advances, and are found in the majority of metastatic samples. PMID:16489013

  18. Gene loss from a plant sex chromosome system.

    PubMed

    Bergero, Roberta; Qiu, Suo; Charlesworth, Deborah

    2015-05-01

    Sex chromosomes have evolved independently in numerous animal and plant lineages. After recombination becomes suppressed between two homologous sex chromosomes, genes on the non-recombining Y chromosomes (and W chromosomes in ZW systems) undergo genetic degeneration, losing functions retained by their X- or Z-linked homologs, changing their expression, and becoming lost [1, 2]. Adaptive changes may also occur, both on the non-recombining Y chromosome, to shut down expression of maladapted genes [3], and on the X chromosome (or the Z in ZW systems), which may evolve dosage compensation to increase low expression or compensate for poor protein function in the heterogametic sex [2, 4, 5]. Although empirical approaches to studying genetic degeneration have been developed for model species [3, 6], the onset and dynamics of these changes are still poorly understood, particularly in de novo evolving sex chromosomes. Sex chromosomes of some plants evolved much more recently than those of mammals, birds, and Drosophila [7-9], making them suitable for studying the early stages of genetic degeneration in de novo evolving sex chromosomes. In plants, haploid selection should oppose gene loss from Y chromosomes, but recent work on sex chromosomes of two plant species has estimated that Y-linked transcripts are lacking for 10%-30% of X-linked genes [10-12]. Here, we provide evidence that, in Silene latifolia, this largely involved losses of Y-linked genes, and not suppressed expression of Y-linked alleles, or gene additions to the X chromosome. Our results also suggest that chromosome-wide dosage compensation does not occur in this plant. PMID:25913399

  19. Chromosome landmarks and autosome-sex chromosome translocations in Rumex hastatulus, a plant with XX/XY1Y2 sex chromosome system.

    PubMed

    Grabowska-Joachimiak, Aleksandra; Kula, Adam; Ksi??czyk, Tomasz; Chojnicka, Joanna; Sliwinska, Elwira; Joachimiak, Andrzej J

    2015-06-01

    Rumex hastatulus is the North American endemic dioecious plant with heteromorphic sex chromosomes. It is differentiated into two chromosomal races: Texas (T) race characterised by a simple XX/XY sex chromosome system and North Carolina (NC) race with a polymorphic XX/XY1Y2 sex chromosome system. The gross karyotype morphology in NC race resembles the derived type, but chromosomal changes that occurred during its evolution are poorly understood. Our C-banding/DAPI and fluorescence in situ hybridization (FISH) experiments demonstrated that Y chromosomes of both races are enriched in DAPI-positive sequences and that the emergence of polymorphic sex chromosome system was accompanied by the break of ancestral Y chromosome and switch in the localization of 5S rDNA, from autosomes to sex chromosomes (X and Y2). Two contrasting domains were detected within North Carolina Y chromosomes: the older, highly heterochromatinised, inherited from the original Y chromosome and the younger, euchromatic, representing translocated autosomal material. The flow-cytometric DNA estimation showed ?3.5 % genome downsizing in the North Carolina race. Our results are in contradiction to earlier reports on the lack of heterochromatin within Y chromosomes of this species and enable unambiguous identification of autosomes involved in the autosome-heterosome translocation, providing useful chromosome landmarks for further studies on the karyotype and sex chromosome differentiation in this species. PMID:25394583

  20. Cretaceous park of sex determination: sex chromosomes are conserved across iguanas.

    PubMed

    Rovatsos, Michail; Pokorná, Martina; Altmanová, Marie; Kratochvíl, Lukáš

    2014-03-01

    Many poikilothermic vertebrate lineages, especially among amphibians and fishes, possess a rapid turnover of sex chromosomes, while in endotherms there is a notable stability of sex chromosomes. Reptiles in general exhibit variability in sex-determining systems; as typical poikilotherms, they might be expected to have a rapid turnover of sex chromosomes. However, molecular data which would enable the testing of the stability of sex chromosomes are lacking in most lineages. Here, we provide molecular evidence that sex chromosomes are highly conserved across iguanas, one of the most species-rich clade of reptiles. We demonstrate that members of the New World families Iguanidae, Tropiduridae, Leiocephalidae, Phrynosomatidae, Dactyloidae and Crotaphytidae, as well as of the family Opluridae which is restricted to Madagascar, all share homologous sex chromosomes. As our sampling represents the majority of the phylogenetic diversity of iguanas, the origin of iguana sex chromosomes can be traced back in history to the basal splitting of this group which occurred during the Cretaceous period. Iguanas thus show a stability of sex chromosomes comparable to mammals and birds and represent the group with the oldest sex chromosomes currently known among amniotic poikilothermic vertebrates. PMID:24598109

  1. Chromosome evolution in fish: sex chromosome variability in Eigenmannia virescens (Gymnotiformes: Sternopygidae).

    PubMed

    de Almeida-Toledo, L F; Daniel-Silva, M F Z; Moysés, C B; Fonteles, S B A; Lopes, C E; Akama, A; Foresti, F

    2002-01-01

    New data are presented on the sex chromosomes of the fish species Eigenmannia virescens (Gymnotiformes, Sternopygidae). A new finding, involving the occurrence of ZZ/ZW sex chromosomes, is described in specimens sampled from the Săo Francisco and Amazon river basins in Brazil. All individuals had a chromosome number of 2n = 38. The homologs of the sex chromosome pair from the Săo Francisco river basin sample differed only in their morphology, while those from the Amazonian sample differed both in morphology and heterochromatin pattern. A possible model for the evolution of the sex chromosomes in E. virescens is proposed, including data from populations from the Paraná (Brazil) river basin, in which male heterogamety has already been described. The occurrence of different sex chromosome systems in species and populations of the neotropical freshwater fish fauna is discussed. PMID:12900560

  2. Sex chromosome evolution in Simulium erythrocephalum (Diptera: Simuliidae)

    Microsoft Academic Search

    R J Post

    1985-01-01

    The sex chromosomes of Simulium erythrocephalum show a pattern of serial differentiation by the linkage of inversions to either X or Y. Two inversion systems, IL-A and IS-B+I+G are maintained in stable polymorphism with sex differences in frequency throughout southern England. These inversions are linked to the sex chromosomes such that males are more likely to be heterozygous. Heterozygosity and

  3. Multiple sex chromosome systems in howler monkeys (Platyrrhini, Alouatta).

    PubMed

    Steinberg, Eliana Ruth; Nieves, Mariela; Mudry, Marta Dolores

    2014-01-01

    In light of the multiple sex chromosome systems observed in howler monkeys (Alouatta Lacépčde, 1799) a combined cladistic analysis using chromosomal and molecular characters was applied to discuss the possible origin of these systems. Mesoamerican and South American howlers were karyologically compared. FISH analysis using the chromosome painting probes for the #3 and #15 human chromosomes was applied to corroborate the homeology of the sexual systems. We found that the HSA3/15 syntenic association, present in the sex chromosome systems of South American Howlers, is not present in those of Mesoamerican ones. The autosomes involved in the translocation that formed the sexual systems in the Mesoamerican and South American species are different, thus suggesting an independent origin. Parsimony analysis resolved the phylogenetic relationships among howler species, demonstrating utility of the combined approach. A hypothesis for the origin of the multiple sex chromosome systems for the genus is proposed. PMID:24744833

  4. Multiple sex chromosome systems in howler monkeys (Platyrrhini, Alouatta)

    PubMed Central

    Steinberg, Eliana Ruth; Nieves, Mariela; Mudry, Marta Dolores

    2014-01-01

    Abstract In light of the multiple sex chromosome systems observed in howler monkeys (Alouatta Lacépčde, 1799) a combined cladistic analysis using chromosomal and molecular characters was applied to discuss the possible origin of these systems. Mesoamerican and South American howlers were karyologically compared. FISH analysis using the chromosome painting probes for the #3 and #15 human chromosomes was applied to corroborate the homeology of the sexual systems. We found that the HSA3/15 syntenic association, present in the sex chromosome systems of South American Howlers, is not present in those of Mesoamerican ones. The autosomes involved in the translocation that formed the sexual systems in the Mesoamerican and South American species are different, thus suggesting an independent origin. Parsimony analysis resolved the phylogenetic relationships among howler species, demonstrating utility of the combined approach. A hypothesis for the origin of the multiple sex chromosome systems for the genus is proposed. PMID:24744833

  5. The unique sex chromosome system in platypus and echidna.

    PubMed

    Ferguson-Smith, M A; Rens, W

    2010-10-01

    A striking example of the power of chromosome painting has been the resolution of the male platypus karyotype and the pairing relationships of the chain often sex chromosomes. We have extended our analysis to the nine sex chromosomes of the male echidna. Cross-species painting with platypus shows that the first five chromosomes in the chain are identical in both, but the order of the remainder are different and, in each species, a different autosome replaces one of the five X chromosomes. As the therian X is homologous mainly to platypus autosome 6 and echidna 16, and as SRY is absent in both, the sex determination mechanism in monotremes is currently unknown. Several of the X and Y chromosomes contain genes orthologous to those in the avian Z but the significance of this is also unknown. It seems likely that a novel testis determinant is carried by a Y chromosome common to platypus and echidna. We have searched for candidates for this determinant among the many genes known to be involved in vertebrate sex differentiation. So far fourteen such genes have been mapped, eleven are autosomal in platypus, two map to the differential regions of X chromosomes, and one maps to a pairing segment and is likewise excluded. Search for the platypus testis-determining gene continues, and the extension of comparative mapping between platypus and birds and reptiles may shed light on the ancestral origin of monotreme sex chromosomes. PMID:21250543

  6. Mitotic chromosomes and the W-sex chromosome of the great horned owl (Bubo V. virginianus)

    Microsoft Academic Search

    Awtar Krishan; G. J. Haiden; R. N. Shoffner

    1965-01-01

    Mitotic chromosomes from the feather pulp and leucocyte cultures of the great horned owl (Bubo v. virginianus) were analyzed in both the sexes. The largest pair of chromosomes are acrocentrics while those of the second and the third pair have a short arm 1\\/6th the size of the large one. Chromosomes of the fourth and the fifth pairs have a

  7. Long-term persistence of nonpathogenic clonal chromosome abnormalities in donor hematopoietic cells following allogenic stem cell transplantation

    PubMed Central

    Erdag, Gulsun; Meck, Jeanne; Meloni-Ehrig, Aurelia; Matyakhina, Ludmila; Donohue, Theresa; Srinivasan, Ramaprasad; Mowrey, Philip; Kelly, JoAnn; Smith, Aleah; Childs, Richard

    2009-01-01

    We describe two unrelated patients who exhibited multiple chromosomal abnormalities in donor cells after allogeneic peripheral blood stem cell transplantation (PBSCT). The patients were diagnosed with chronic myeloid leukemia and chronic lymphocytic leukemia, respectively, and both underwent non-myeloablative conditioning with cyclophosphamide and fludarabine followed by PBSCT from their HLA-matched opposite-sex siblings. Post-transplant bone marrow cytogenetics showed full engraftment, and the early post-transplant studies demonstrated only normal donor metaphases. Subsequent studies of both patients, however, revealed a population of metaphase cells with abnormal, but apparently balanced, karyotypes. Chromosome studies performed on peripheral blood cells collected from both donors after transplantation were normal. Both patients remained in clinical remission during follow-up of up almost 6 years, despite the persistence of the abnormal clones. Chromosomal abnormalities in residual recipient cells after bone marrow or PBSCT are not unusual. In contrast, only rare reports of chromosome abnormalities in donor cells exist, all of which have been associated with post-bone marrow transplant myelodysplastic syndrome or acute leukemias. Ours is the first report of persistent clonal non-pathogenic chromosome aberrations in cells of donor origin. PMID:19380032

  8. An XX/XY heteromorphic sex chromosome system in the Australian chelid turtle Emydura macquarii: A new piece in the puzzle of sex chromosome

    E-print Network

    Canberra, University of

    An XX/XY heteromorphic sex chromosome system in the Australian chelid turtle Emydura macquarii: A new piece in the puzzle of sex chromosome evolution in turtles Pedro Alonzo Martinez1 *, Tariq Ezaz2, Emydura, evolution, G-banding, sex chromosomes, sex determination, speciation, turtles Abstract

  9. ETOPOSIDE INDUCES CHROMOSOMAL ABNORMALITIES IN SPERMATOCYTES AND SPERMATOGONIAL STEM CELLS

    SciTech Connect

    Marchetti, F; Pearson, F S; Bishop, J B; Wyrobek, A J

    2005-07-15

    Etoposide (ET) is a chemotherapeutic agent widely used in the treatment of leukemia, lymphomas and many solid tumors, such as testicular and ovarian cancers, that affect patients in their reproductive years. The purpose of the study was to use sperm FISH analyses to characterize the long-term effects of ET on male germ cells. We used a mouse model to characterize the induction of chromosomal aberrations (partial duplications and deletions) and whole chromosomal aneuploidies in sperm of mice treated with a clinical dose of ET. Semen samples were collected at 25 and 49 days after dosing to investigate the effects of ET on meiotic pachytene cells and spermatogonial stem-cells, respectively. ET treatment resulted in major increases in the frequencies of sperm carrying chromosomal aberrations in both meiotic pachytene (27- to 578-fold) and spermatogonial stem-cells (8- to 16-fold), but aneuploid sperm were induced only after treatment of meiotic cells (27-fold) with no persistent effects in stem cells. These results demonstrate that male meiotic germ cells are considerably more sensitive to ET than spermatogonial stem-cell and that increased frequencies of sperm with structural aberrations persist after spermatogonial stem-cell treatment. These findings predict that patients who undergo chemotherapy with ET may have transient elevations in the frequencies of aneuploid sperm, but more importantly, may have persistent elevations in the frequencies of sperm with chromosomal aberrations, placing them at higher risk for abnormal reproductive outcomes long after the end of their chemotherapy.

  10. Excessive centrosome abnormalities without ongoing numerical chromosome instability in a Burkitt's lymphoma

    Microsoft Academic Search

    Stefan Duensing; Benjamin H Lee; Paola Dal Cin; Karl Münger

    2003-01-01

    Numerical and structural centrosome abnormalities are detected in various human malignancies and have been implicated in the formation of multipolar mitoses, chromosome missegregation, and chromosomal instability. Despite this association between centrosome abnormalities and cancerous growth, a causative role of centrosome aberrations in generating chromosomal instability and aneuploidy has not been universally established. We report here excessive numerical and structural centrosome

  11. A Neo-Sex Chromosome That Drives Postzygotic Sex Determination in the Hessian Fly (Mayetiola destructor)

    PubMed Central

    Benatti, Thiago R.; Valicente, Fernando H.; Aggarwal, Rajat; Zhao, Chaoyang; Walling, Jason G.; Chen, Ming-Shun; Cambron, Sue E.; Schemerhorn, Brandon J.; Stuart, Jeffrey J.

    2010-01-01

    Two nonoverlapping autosomal inversions defined unusual neo-sex chromosomes in the Hessian fly (Mayetiola destructor). Like other neo-sex chromosomes, these were normally heterozygous, present only in one sex, and suppressed recombination around a sex-determining master switch. Their unusual properties originated from the anomalous Hessian fly sex determination system in which postzygotic chromosome elimination is used to establish the sex-determining karyotypes. This system permitted the evolution of a master switch (Chromosome maintenance, Cm) that acts maternally. All of the offspring of females that carry Cm-associated neo-sex chromosomes attain a female-determining somatic karyotype and develop as females. Thus, the chromosomes act as maternal effect neo-W's, or W-prime (W?) chromosomes, where ZW? females mate with ZZ males to engender female-producing (ZW?) and male-producing (ZZ) females in equal numbers. Genetic mapping and physical mapping identified the inversions. Their distribution was determined in nine populations. Experimental matings established the association of the inversions with Cm and measured their recombination suppression. The inversions are the functional equivalent of the sciarid X-prime chromosomes. We speculate that W? chromosomes exist in a variety of species that produce unisexual broods. PMID:20026681

  12. Loss of sex chromosomes in the hematopoietic disorders: Questions, concerns and data interpretation

    Microsoft Academic Search

    Slovak

    1994-01-01

    The significance of sex chromosome aberrations in the hematopoietic disorders has not yet been defined. Interpretive problems stem from (1) the loss of a sex chromosome associated with aging, (2) sex chromosome loss as the sole aberration in leukemia is rare, (3) random -(X or Y) is observed frequently in bone marrow samples, and (4) constitutional sex chromosome anomalies must

  13. FResHU F3 Green Symposia Series #6 Acquisition of neo-sex chromosomes and sex-determining system

    E-print Network

    Ishii, Hitoshi

    FResHU F3 Green Symposia Series #6 Acquisition of neo-sex chromosomes and sex-determining system Sex chromosome turnover contributed to speciation in three-spine sticklebacks Early evolution from autosomes to sex chromosomes in eutherian mammal - a case of Tokduaia muenninki - The molecular mechanism

  14. The Sex Chromosomes of Frogs: Variability and Tolerance Offer Clues to Genome Evolution and Function

    PubMed Central

    Malcom, Jacob W.; Kudra, Randal S.; Malone, John H.

    2014-01-01

    Frog sex chromosomes offer an ideal system for advancing our understanding of genome evolution and function because of the variety of sex determination systems in the group, the diversity of sex chromosome maturation states, the ease of experimental manipulation during early development. After briefly reviewing sex chromosome biology generally, we focus on what is known about frog sex determination, sex chromosome evolution, and recent, genomics-facilitated advances in the field. In closing we highlight gaps in our current knowledge of frog sex chromosomes, and suggest priorities for future research that can advance broad knowledge of gene dose and sex chromosome evolution. PMID:25031658

  15. Prospective studies on children with sex chromosome aneuploidy

    SciTech Connect

    Ratcliffe, S.G.; Paul, N.

    1986-01-01

    This book contains 11 selections. Some of the titles are: Growth and Development from Early to Midadolescence of Children with X and Y Chromosome Aneuploidy: The Toronto Study; Sex Chromomal Aneuploidy: Perspective and Longitudinal Studies; Psychologic Study of XYY and XXY Men; and Cellular and Molecular Studies in Human Chromosomal Diseases.

  16. Sex Chromosomes: Evolution of the Weird and Wonderful

    Microsoft Academic Search

    Deborah Charlesworth; Brian Charlesworth

    2005-01-01

    New findings in the platypus and Drosophila pseudoobscura illustrate, yet again, that the sex chromosomes seem never to stop evolving. Degeneration processes lead to a continual loss of genes and gene activity on the Y chromosome, and complete loss of Y-linked genes is possible if autosomal genes take over control of male fertility – though addition of new material to

  17. Counseling parents before prenatal diagnosis: do we need to say more about the sex chromosome aneuploidies?

    PubMed

    Lalatta, Faustina; Tint, G Stephen

    2013-11-01

    Sex chromosome trisomies (SCT), an extra X chromosome in females (triple X, XXX), males with an extra X chromosome (Klinefelter syndrome, XXY) or an extra Y chromosome (XYY) occur because of errors during meiosis and are relatively frequent in humans. Their identification has never been the goal of prenatal diagnosis (PD) but they almost never escape detection by any of the methods commonly in use. Despite recommendations and guide-lines which emphasize the importance of structured counseling before and after PD, most women remain unaware that testing for serious genetic abnormalities is more likely to uncover these trisomies. With the increasing use of PD more and more prospective parents receive a diagnosis of sex chromosome trisomies and are faced with the dilemma of whether to terminate the pregnancy or to carry it to term. Despite the dramatic and emotionally devastating consequences of having to make such a decision, they have little opportunity to consider in advance the possible outcomes of such a pregnancy and, rather than relying on their own feelings and judgements, are forced to depend on the advice of counseling professionals who may or may not themselves be fully aware of what having an extra sex chromosome can mean to the development of a child. We address here the principles of reproductive autonomy together with an analysis of the major issues that ought to be discussed with the parents before a PD is carried out in order to minimize detrimental effects caused by this unexpected finding. PMID:24115600

  18. Homomorphic plant sex chromosomes are coming of age.

    PubMed

    Filatov, Dmitry A

    2015-07-01

    Sex chromosomes are a very peculiar part of the genome that have evolved independently in many groups of animals and plants (Bull ). Major research efforts have so far been focused on large heteromorphic sex chromosomes in a few animal and plant species (Chibalina & Filatov ; Zhou & Bachtrog ; Bellott et al. ; Hough et al. ; Zhou et al. ), while homomorphic (cytologically indistinguishable) sex chromosomes have largely been neglected. However, this situation is starting to change. In this issue, Geraldes et al. () describe a small (~100 kb long) sex-determining region on the homomorphic sex chromosomes of poplars (Populus trichocarpa and related species, Fig. ). All species in Populus and its sister genus Salix are dioecious, suggesting that dioecy and the sex chromosomes, if any, should be relatively old. Contrary to this expectation, Geraldes et al. () demonstrate that the sex-determining region in poplars is of very recent origin and probably evolved within the genus Populus only a few million years ago. PMID:26113024

  19. Haploinsufficiency and the sex chromosomes from yeasts to humans

    PubMed Central

    2011-01-01

    Background Haploinsufficient (HI) genes are those for which a reduction in copy number in a diploid from two to one results in significantly reduced fitness. Haploinsufficiency is increasingly implicated in human disease, and so predicting this phenotype could provide insights into the genetic mechanisms behind many human diseases, including some cancers. Results In the present work we show that orthologues of Saccharomyces cerevisiae HI genes are preferentially retained across the kingdom Fungi, and that the HI genes of S. cerevisiae can be used to predict haploinsufficiency in humans. Our HI gene predictions confirm known associations between haploinsufficiency and genetic disease, and predict several further disorders in which the phenotype may be relevant. Haploinsufficiency is also clearly relevant to the gene-dosage imbalances inherent in eukaryotic sex-determination systems. In S. cerevisiae, HI genes are over-represented on chromosome III, the chromosome that determines yeast's mating type. This may be a device to select against the loss of one copy of chromosome III from a diploid. We found that orthologues of S. cerevisiae HI genes are also over-represented on the mating-type chromosomes of other yeasts and filamentous fungi. In animals with heterogametic sex determination, accumulation of HI genes on the sex chromosomes would compromise fitness in both sexes, given X chromosome inactivation in females. We found that orthologues of S. cerevisiae HI genes are significantly under-represented on the X chromosomes of mammals and of Caenorhabditis elegans. There is no X inactivation in Drosophila melanogaster (increased expression of X in the male is used instead) and, in this species, we found no depletion of orthologues to yeast HI genes on the sex chromosomes. Conclusion A special relationship between HI genes and the sex/mating-type chromosome extends from S. cerevisiae to Homo sapiens, with the microbe being a useful model for species throughout the evolutionary range. Furthermore, haploinsufficiency in yeast can predict the phenotype in higher organisms. PMID:21356089

  20. The role of sex chromosomes in mammalian germ cell differentiation: can the germ cells carrying X and Y chromosomes differentiate into fertile oocytes?

    PubMed Central

    Taketo, Teruko

    2015-01-01

    The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions. PMID:25578929

  1. Cross-species chromosome painting tracks the independent origin of multiple sex chromosomes in two cofamiliar Erythrinidae fishes

    PubMed Central

    2011-01-01

    Background The Erythrinidae fish family is characterized by a large variation with respect to diploid chromosome numbers and sex-determining systems among its species, including two multiple X1X2Y sex systems in Hoplias malabaricus and Erythrinus erythrinus. At first, the occurrence of a same sex chromosome system within a family suggests that the sex chromosomes are correlated and originated from ancestral XY chromosomes that were either homomorphic or at an early stage of differentiation. To identify the origin and evolution of these X1X2Y sex chromosomes, we performed reciprocal cross-species FISH experiments with two sex-chromosome-specific probes designed from microdissected X1 and Y chromosomes of H. malabaricus and E. erythrinus, respectively. Results Our results yield valuable information regarding the origin and evolution of these sex chromosome systems. Our data indicate that these sex chromosomes evolved independently in these two closed related Erythrinidae species. Different autosomes were first converted into a poorly differentiated XY sex pair in each species, and additional chromosomal rearrangements produced both X1X2Y sex systems that are currently present. Conclusions Our data provide new insights into the origin and evolution of sex chromosomes, which increases our knowledge about fish sex chromosome evolution. PMID:21718509

  2. ORIGINAL ARTICLE Distance segregation of sex chromosomes in crane-fly

    E-print Network

    Chen, Zhongping

    microbeam, to create two chromatids. In both sex-chromosome metaphase and sex- chromosome anaphase, the two metaphase chromosomes are attached to spindle fibres that extend to opposite poles: after disjunctionORIGINAL ARTICLE Distance segregation of sex chromosomes in crane-fly spermatocytes studied using

  3. Chromosome abnormalities and the genetics of congenital corneal opacification.

    PubMed

    Mataftsi, A; Islam, L; Kelberman, D; Sowden, J C; Nischal, K K

    2011-01-01

    Congenital corneal opacification (CCO) encompasses a broad spectrum of disorders that have different etiologies, including genetic and environmental. Terminology used in clinical phenotyping is commonly not specific enough to describe separate entities, for example both the terms Peters anomaly and sclerocornea have been ascribed to a clinical picture of total CCO, without investigating the presence or absence of iridocorneal adhesions. This is not only confusing but also unhelpful in determining valid genotype-phenotype correlations, and thereby revealing clues for pathogenesis. We undertook a systematic review of the literature focusing on CCO as part of anterior segment developmental anomalies (ASDA), and analyzed its association specifically with chromosomal abnormalities. Genes previously identified as being associated with CCO are also summarized. All reports were critically appraised to classify phenotypes according to described features, rather than the given diagnosis. Some interesting associations were found, and are discussed. PMID:21738392

  4. Chromosomal Gene Movements Reflect the Recent Origin and Biology of Therian Sex Chromosomes

    E-print Network

    Paris-Sud XI, Université de

    Chromosomal Gene Movements Reflect the Recent Origin and Biology of Therian Sex Chromosomes Lukasz ancestral autosomes and have substantially differentiated. It was shown that X-linked genes have generated duplicate intronless gene copies (retrogenes) on autosomes due to this differentiation. However, the precise

  5. Chromosomal distribution of cyto-nuclear genes in a dioecious plant with sex chromosomes

    E-print Network

    Barrett, C.H.

    1 LETTER Chromosomal distribution of cyto-nuclear genes in a dioecious plant with sex title: Cyto-nuclear interactions in a dioecious plant Key words: Cyto-nuclear interactions, co to conduct the first study of the chromosomal distribution of cyto-nuclear interacting genes in a plant

  6. Directly transmitted unbalanced chromosome abnormalities and euchromatic variants

    PubMed Central

    Barber, J

    2005-01-01

    In total, 200 families were reviewed with directly transmitted, cytogenetically visible unbalanced chromosome abnormalities (UBCAs) or euchromatic variants (EVs). Both the 130 UBCA and 70 EV families were divided into three groups depending on the presence or absence of an abnormal phenotype in parents and offspring. No detectable phenotypic effect was evident in 23/130 (18%) UBCA families ascertained mostly through prenatal diagnosis (group 1). In 30/130 (23%) families, the affected proband had the same UBCA as other phenotypically normal family members (group 2). In the remaining 77/130 (59%) families, UBCAs had consistently mild consequences (group 3). In the 70 families with established EVs of 8p23.1, 9p12, 9q12, 15q11.2, and 16p11.2, no phenotypic effect was apparent in 38/70 (54%). The same EV was found in affected probands and phenotypically normal family members in 30/70 families (43%) (group 2), and an EV co-segregated with mild phenotypic anomalies in only 2/70 (3%) families (group 3). Recent evidence indicates that EVs involve copy number variation of common paralogous gene and pseudogene sequences that are polymorphic in the normal population and only become visible at the cytogenetic level when copy number is high. The average size of the deletions and duplications in all three groups of UBCAs was close to 10 Mb, and these UBCAs and EVs form the "Chromosome Anomaly Collection" at http://www.ngrl.org.uk/Wessex/collection. The continuum of severity associated with UBCAs and the variability of the genome at the sub-cytogenetic level make further close collaboration between medical and laboratory staff essential to distinguish clinically silent variation from pathogenic rearrangement. PMID:16061560

  7. Multiple and independent cessation of recombination between avian sex chromosomes.

    PubMed Central

    Ellegren, H; Carmichael, A

    2001-01-01

    Birds are characterized by female heterogamety; females carry the Z and W sex chromosomes, while males have two copies of the Z chromosome. We suggest here that full differentiation of the Z and W sex chromosomes of birds did not take place until after the split of major contemporary lineages, in the late Cretaceous. The ATP synthase alpha-subunit gene is now present in one copy each on the nonrecombining part of the W chromosome (ATP5A1W) and on the Z chromosome (ATP5A1Z). This gene seems to have evolved on several independent occasions, in different lineages, from a state of free recombination into two sex-specific and nonrecombining variants. ATP5A1W and ATP5A1Z are thus more similar within orders, relative to what W (or Z) are between orders. Moreover, this cessation of recombination apparently took place at different times in different lineages (estimated at 13, 40, and 65 million years ago in Ciconiiformes, Galliformes, and Anseriformes, respectively). We argue that these observations are the result of recent and traceable steps in the process where sex chromosomes gradually cease to recombine and become differentiated. Our data demonstrate that this process, once initiated, may occur independently in parallel in sister lineages. PMID:11333240

  8. Evolution of the Avian Sex Chromosomes from an Ancestral Pair of Autosomes

    Microsoft Academic Search

    Anna-Karin Fridolfsson; Hans Cheng; Neal G. Copeland; Nancy A. Jenkins; Hsiao-Ching Liu; Terje Raudsepp; Trevor Woodage; Bhanu Chowdhary; Joy Halverson; Hans Ellegren

    1998-01-01

    Among the mechanisms whereby sex is determined in animals, chromosomal sex determination is found in a wide variety of distant taxa. The widespread but not ubiquitous occurrence, not even within lineages, of chromosomal sex determination suggests that sex chromosomes have evolved independently several times during animal radiation, but firm evidence for this is lacking. The most favored model for this

  9. Genome structure and primitive sex chromosome revealed in Populus

    SciTech Connect

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL; Gunter, Lee E [ORNL; Blaudez, D [UMR, France

    2008-01-01

    We constructed a comprehensive genetic map for Populus and ordered 332 Mb of sequence scaffolds along the 19 haploid chromosomes in order to compare chromosomal regions among diverse members of the genus. These efforts lead us to conclude that chromosome XIX in Populus is evolving into a sex chromosome. Consistent segregation distortion in favor of the sub-genera Tacamahaca alleles provided evidence of divergent selection among species, particularly at the proximal end of chromosome XIX. A large microsatellite marker (SSR) cluster was detected in the distorted region even though the genome-wide distribute SSR sites was uniform across the physical map. The differences between the genetic map and physical sequence data suggested recombination suppression was occurring in the distorted region. A gender-determination locus and an overabundance of NBS-LRR genes were also co-located to the distorted region and were put forth as the cause for divergent selection and recombination suppression. This hypothesis was verified by using fine-scale mapping of an integrated scaffold in the vicinity of the gender-determination locus. As such it appears that chromosome XIX in Populus is in the process of evolving from an autosome into a sex chromosome and that NBS-LRR genes may play important role in the chromosomal diversification process in Populus.

  10. The evolution of sex chromosomes in the genus Rumex (Polygonaceae): Identification of a new species with heteromorphic sex chromosomes.

    PubMed

    Cuńado, Nieves; Navajas-Pérez, Rafael; de la Herrán, Roberto; Ruiz Rejón, Carmelo; Ruiz Rejón, Manuel; Santos, Juan Luis; Garrido-Ramos, Manuel A

    2007-01-01

    The structural features and evolutionary state of the sex chromosomes of the XX/XY species of Rumex are unknown. Here, we report a study of the meiotic behaviour of the XY bivalent in Rumex acetosella and R. suffruticosus, a new species which we describe cytogenetically for the first time in this paper, and also that of the XY(1)Y(2) trivalent of R. acetosa by both conventional cytogenetic techniques and analysis of synaptonemal complex formation. Fluorescent in situ hybridization with satellite DNA and rDNA sequences as probes was used to analyse the degree of cytogenetic differentiation between the X and Y chromosomes in order to depict their evolutionary stage in the three species. Contrasting with the advanced state of genetic differentiation between the X and the Y chromosomes in R. acetosa, we have found that R. acetosella and R. suffruticosus represent an early stage of genetic differentiation between sex chromosomes. Our findings further demonstrate the usefulness of the genus Rumex as a model for analysing the evolution of sex chromosomes in plants, since within this genus it is now possible to study the different levels of genetic differentiation between the sex chromosomes and to analyse their evolutionary history from their origin. PMID:17899410

  11. Neo-sex chromosomes and adaptive potential in tortricid pests.

    PubMed

    Nguyen, Petr; Sýkorová, Miroslava; Šíchová, Jindra; K?ta, Václav; Dalíková, Martina; ?apková Frydrychová, Radmila; Neven, Lisa G; Sahara, Ken; Marec, František

    2013-04-23

    Changes in genome architecture often have a significant effect on ecological specialization and speciation. This effect may be further enhanced by involvement of sex chromosomes playing a disproportionate role in reproductive isolation. We have physically mapped the Z chromosome of the major pome fruit pest, the codling moth, Cydia pomonella (Tortricidae), and show that it arose by fusion between an ancestral Z chromosome and an autosome corresponding to chromosome 15 in the Bombyx mori reference genome. We further show that the fusion originated in a common ancestor of the main tortricid subfamilies, Olethreutinae and Tortricinae, comprising almost 700 pest species worldwide. The Z-autosome fusion brought two major genes conferring insecticide resistance and clusters of genes involved in detoxification of plant secondary metabolites under sex-linked inheritance. We suggest that this fusion significantly increased the adaptive potential of tortricid moths and thus contributed to their radiation and subsequent speciation. PMID:23569222

  12. Neo-sex chromosomes and adaptive potential in tortricid pests

    PubMed Central

    Nguyen, Petr; Sýkorová, Miroslava; Šíchová, Jindra; K?ta, Václav; Dalíková, Martina; ?apková Frydrychová, Radmila; Neven, Lisa G.; Sahara, Ken; Marec, František

    2013-01-01

    Changes in genome architecture often have a significant effect on ecological specialization and speciation. This effect may be further enhanced by involvement of sex chromosomes playing a disproportionate role in reproductive isolation. We have physically mapped the Z chromosome of the major pome fruit pest, the codling moth, Cydia pomonella (Tortricidae), and show that it arose by fusion between an ancestral Z chromosome and an autosome corresponding to chromosome 15 in the Bombyx mori reference genome. We further show that the fusion originated in a common ancestor of the main tortricid subfamilies, Olethreutinae and Tortricinae, comprising almost 700 pest species worldwide. The Z–autosome fusion brought two major genes conferring insecticide resistance and clusters of genes involved in detoxification of plant secondary metabolites under sex-linked inheritance. We suggest that this fusion significantly increased the adaptive potential of tortricid moths and thus contributed to their radiation and subsequent speciation. PMID:23569222

  13. Sex Steroids and Sex Chromosomes at Odds? Alfred Jost's proposal in the 1940s (1) that testes are crucial

    E-print Network

    de Vries, Geert J.

    Sex Steroids and Sex Chromosomes at Odds? Alfred Jost's proposal in the 1940s (1) that testes of sexual differentiation into `Sex chromosomal genes determine the differentiation of the go- nads doctrine may not be as generally applicable as first thought. Several sex differences, for example in bird

  14. Weird animal genomes and the evolution of vertebrate sex and sex chromosomes.

    PubMed

    Marshall Graves, Jennifer A

    2008-01-01

    Humans, mice, and even kangaroos have an XX female:XY male system of sex determination, in which the Y harbors a male-dominant sex-determining gene SRY. Birds have the opposite, ZZ males and ZW females, and may use a dosage-sensitive Z-borne gene. Other reptiles have genetic sex but no visible sex chromosomes, or determine sex by temperature of egg incubation. How can we make sense of so much variation? How do systems change in evolution? Studies of some unlikely animals-platypus and dragon lizards, frogs and fish-confirm that evolutionary transitions have occurred between TSD and GSD systems, between XY and ZW systems, and even between male and female heterogametic systems. Here I explore nonmodel systems that offer some new perspectives on some venerable questions of sex and sex chromosomes. PMID:18983263

  15. Silene latifolia: the classical model to study heteromorphic sex chromosomes.

    PubMed

    Kejnovsky, E; Vyskot, B

    2010-07-01

    This review summarizes older as well as recent data about the model dioecious plant Silene latifolia. This plant has been the subject of more than one hundred years of research efforts and its most conspicuous property is huge and well differentiated heteromorphic sex chromosomes, XX in females and XY in males. Due to this property the S. latifolia sex chromosomes have been often used for cytogenetic studies as well as for flow sorting and laser microdissection. Nowadays S. latifolia is the focus of genomic studies, molecular mapping, phylogenetic and population genetics analyses. PMID:20551610

  16. A sex-chromosome mutation in Silene latifolia.

    PubMed

    Miller, Paige M; Kesseli, Richard V

    2011-09-01

    Silene latifolia is dioecious, yet rare hermaphrodites have been found, and such natural mutants can provide valuable insight into genetic mechanisms. Here, we describe a hermaphrodite-inducing mutation that is almost certainly localized to the gynoecium-suppression region of the Y chromosome in S. latifolia. The mutant Y chromosome was passed through the megaspore, and the presence of two X chromosomes was not necessary for seed development in the parent. This result supports a lack of degeneration of the Y chromosome in S. latifolia, consistent with the relatively recent formation of the sex chromosomes in this species. When crossed to wild-type plants, hermaphrodites performed poorly as females, producing low seed numbers. When hermaphrodites were pollen donors, the sex ratio of offspring they produced through crosses was biased towards females. This suggests that hermaphroditic S. latifolia would fail to thrive and potentially explains the rarity of hermaphrodites in natural populations of S. latifolia. These results indicate that the Y chromosome in Silene latifolia remains very similar to the X, perhaps mostly differing in the primary sex determination regions. PMID:21380711

  17. Chromosomal Abnormalities Chromosomal abnormalities

    E-print Network

    Dellaire, Graham

    ; Growth failure Mental retardation Flat occiput Dysplastic ears Intestinal stenosis Hypotonic muscles tongue Short, broad hands Congenital heart disease Trisomy 21 #12; Trisomy 18 Mental retardation Rarely survive to birth (1/7500 births) #12; Trisomy 13 Severe mental retardation, growth retardation

  18. An accumulation of tandem DNA repeats on the Y chromosome in Silene latifolia during early stages of sex chromosome evolution

    Microsoft Academic Search

    Roman Hobza; Martina Lengerova; Julia Svoboda; Hana Kubekova; Eduard Kejnovsky; Boris Vyskot

    2006-01-01

    Sex chromosomes in mammals are about 300 million years old and typically have a highly degenerated Y chromosome. The sex chromosomes in the dioecious plant Silene latifolia in contrast, represent an early stage of evolution in which functional X–Y gene pairs are still frequent. In this study, we characterize a novel tandem repeat called TRAYC, which has accumulated on the

  19. Variation in the levels of pregnancy-specific beta-1-glycoprotein in maternal serum from chromosomally abnormal pregnancies.

    PubMed

    Graham, G W; Crossley, J A; Aitken, D A; Connor, J M

    1992-06-01

    Human pregnancy-specific beta-1-glycoprotein (SP1) was assayed retrospectively in stored maternal serum (MS) samples from 82 chromosomally abnormal pregnancies and 377 matched controls. The median MSSP1 concentration in 48 Down's syndrome pregnancies was significantly elevated at 1.17 multiples of the control median (MOM), and significantly reduced (0.5 MOM) in a group of eight cases of unbalanced translocations. There was no significant difference in median SP1 concentrations in cases of trisomy 18, trisomy 13, balanced translocations, or sex chromosome abnormalities. A comparison with human chorionic gonadotrophin results in the same series of samples indicates that SP1 is a less sensitive predictor of Down's syndrome pregnancies. PMID:1387478

  20. Aberrant Chromosomal Sex-Determining Mechanisms in Mammals, with Special Reference to Species with XY Females

    Microsoft Academic Search

    K. Fredga; M. G. Bulmer

    1988-01-01

    Both mouse and man have the common XX\\/XY sex chromosome mechanism. The X chromosome is of original size (5-6% of female haploid set) and the Y is one of the smallest chromosomes of the complement. But there are species, belonging to a variety of orders, with composite sex chromosomes and multiple sex chromosome systems: XX\\/XY_1Y_2 and X_1X_1X_2X_2\\/X_1X_2Y. The original X

  1. Sex-chromosome aberrations in wood lemmings (Myopus schisticolor)

    Microsoft Academic Search

    A. Gropp; H. Winking; F. Frank; G. Noack; K. Fredga

    1976-01-01

    The wood lemming displays certain peculiar features: (1) The sex ratio shows a prevalence of females (Frank, 1966; Kalela and Oksala, 1966), and some females produce only female offspring (Kalela and Oksala, 1966). (2) In a considerable proportion (in the present material, slightly less than half) of the females, an XY chromosome complement is found in the somatic tissues, but

  2. Mitotic cycles in human cell strains with sex chromosomes aneuploidy

    Microsoft Academic Search

    V. I. Kukharenko; K. N. Grinberg; A. M. Kuliev

    1978-01-01

    A persistence of the embryonic type of mitotic cycle was found in postnatal strains with aneuploidy of sex chromosomes (45,X; 47,XXX; 49,XXXXX;47,XYY;49,XXXXY). Life-span and proliferating activity of the strains did not differ from those of diploid postnatal cells.

  3. DNA methylation of sex chromosomes in a dioecious plant, Melandrium album

    Microsoft Academic Search

    Boris Vyskot; Alejandro Araya; Jacky Veuskens; Ioan Negrutiu; Armand Mouras

    1993-01-01

    Melandrium album, a dioecious plant species, has two heteromorphic sex chromosomes with the XY constitution typical for male and the XX for female plants. This plant represents an experimental model system of sex determination in which the Y chromosome plays a strongly dominant male role. We present data on the overall transcriptional activities of M. album sex chromosomes. DNA methylation

  4. CYTOGENETIC ABNORMALITY IN MAN—Wider Implications of Theories of Sex Chromatin Origin

    PubMed Central

    Miles, Charles P.

    1962-01-01

    Female nuclei may be identified by means of sex chromatin. In general the number of sex chromatin bodies is one less than the number of X chromosomes. An exception to this rule is a case of sex chromatin-positive XO Turner's syndrome. This case suggests the possibility of sex chromatin-positive XY males, and it may be evidence for chromosomal differentiation. PMID:14473851

  5. Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease

    PubMed Central

    AbouAlaiwi, Wissam A.; Rodriguez, Ingrid; Nauli, Surya M.

    2012-01-01

    Conventional method to identify and classify individual chromosomes depends on the unique banding pattern of each chromosome in a specific species being analyzed 1, 2. This classical banding technique, however, is not reliable in identifying complex chromosomal aberrations such as those associated with cancer. To overcome the limitations of the banding technique, Spectral Karyotyping (SKY) is introduced to provide much reliable information on chromosome abnormalities. SKY is a multicolor fluorescence in-situ hybridization (FISH) technique to detect metaphase chromosomes with spectral microscope 3, 4. SKY has been proven to be a valuable tool for the cytogenetic analysis of a broad range of chromosome abnormalities associated with a large number of genetic diseases and malignancies 5, 6. SKY involves the use of multicolor fluorescently-labelled DNA probes prepared from the degenerate oligonucleotide primers by PCR. Thus, every chromosome has a unique spectral color after in-situ hybridization with probes, which are differentially labelled with a mixture of fluorescent dyes (Rhodamine, Texas Red, Cy5, FITC and Cy5.5). The probes used for SKY consist of up to 55 chromosome specific probes 7-10. The procedure for SKY involves several steps (Figure 1). SKY requires the availability of cells with high mitotic index from normal or diseased tissue or blood. The chromosomes of a single cell from either a freshly isolated primary cell or a cell line are spread on a glass slide. This chromosome spread is labeled with a different combination of fluorescent dyes specific for each chromosome. For probe detection and image acquisition,the spectral imaging system consists of sagnac interferometer and a CCD camera. This allows measurement of the visible light spectrum emitted from the sample and to acquire a spectral image from individual chromosomes. HiSKY, the software used to analyze the results of the captured images, provides an easy identification of chromosome anomalies. The end result is a metaphase and a karyotype classification image, in which each pair of chromosomes has a distinct color (Figure 2). This allows easy identification of chromosome identities and translocations. For more details, please visit Applied Spectral Imaging website (http://www.spectral-imaging.com/). SKY was recently used for an identification of chromosome segregation defects and chromosome abnormalities in humans and mice with Autosomal Dominant Polycystic Kidney Disease (ADPKD), a genetic disease characterized by dysfunction in primary cilia 11-13. Using this technique, we demonstrated the presence of abnormal chromosome segregation and chromosomal defects in ADPKD patients and mouse models 14. Further analyses using SKY not only allowed us to identify chromosomal number and identity, but also to accurately detect very complex chromosomal aberrations such as chromosome deletions and translocations (Figure 2). PMID:22330078

  6. Chromosome mapping of repetitive sequences in Anostomidae species: implications for genomic and sex chromosome evolution

    PubMed Central

    2012-01-01

    Background Members of the Anostomidae family provide an interesting model system for the study of the influence of repetitive elements on genome composition, mainly because they possess numerous heterochromatic segments and a peculiar system of female heterogamety that is restricted to a few species of the Leporinus genus. The aim of this study was to isolate and identify important new repetitive DNA elements in Anostomidae through restriction enzyme digestion, followed by cloning, characterisation and chromosome mapping of this fragment. To identify repetitive elements in other Leporinus species and expand on studies of repetitive elements in Anostomidae, hybridisation experiments were also performed using previously described probes of LeSpeI repetitive elements. Results The 628-base pair (bp) LeSpeII fragment was hybridised to metaphase cells of L. elongatus individuals as well as those of L. macrocephalus, L. obtusidens, L. striatus, L. lacustris, L. friderici, Schizodon borellii and S. isognathus. In L. elongatus, both male and female cells contained small clusters of LeSpeII repetitive elements dispersed on all of the chromosomes, with enrichment near most of the terminal portions of the chromosomes. In the female sex chromosomes of L. elongatus (Z2,Z2/W1W2), however, this repeated element was absent. In the remaining species, a dispersed pattern of hybridisation was observed on all chromosomes irrespective of whether or not they were sex chromosomes. The repetitive element LeSpeI produced positive hybridisations signals only in L. elongatus, L. macrocephalus and L. obtusidens, i.e., species with differentiated sex chromosomes. In the remaining species, the LeSpeI element did not produce hybridisation signals. Conclusions Results are discussed in terms of the effects of repetitive sequences on the differentiation of the Anostomidae genome, especially with respect to sex chromosome evolution. LeSpeII showed hybridisation patterns typical of Long Interspersed Elements (LINEs). The differential distribution of this element may be linked to sex chromosome differentiation in L. elongatus species. The relationship between sex chromosome specificity and the LeSpeI element is confirmed in the species L. elongatus, L. macrocephalus and L. obtusidens. PMID:23228116

  7. Spectral karyotyping refines cytogenetic diagnostics of constitutional chromosomal abnormalities

    Microsoft Academic Search

    Evelin Schröck; Tim Veldman; Hesed Padilla-Nash; Yi Ning; Jack Spurbeck; Syed Jalal; Lisa G. Shaffer; Peter Papenhausen; Chahira Kozma; Mary C. Phelan; Eigil Kjeldsen; Stephen A. Schonberg; Patricia O’Brien; Les Biesecker; Stan du Manoir; Thomas Ried

    1997-01-01

    Karyotype analysis by chromosome banding is the standard method for identifying numerical and structural chromosomal aberrations\\u000a in pre- and postnatal cytogenetics laboratories. However, the chromosomal origins of markers, subtle translocations, or complex\\u000a chromosomal rearrangements are often difficult to identify with certainty. We have developed a novel karyotyping technique,\\u000a termed spectral karyotyping (SKY), which is based on the simultaneous hybridization of

  8. Avian sex, sex chromosomes, and dosage compensation in the age of genomics.

    PubMed

    Graves, Jennifer A Marshall

    2014-04-01

    Comparisons of the sex chromosome systems in birds and mammals are widening our view and deepening our understanding of vertebrate sex chromosome organization, function, and evolution. Birds have a very conserved ZW system of sex determination in which males have two copies of a large, gene-rich Z chromosome, and females have a single Z and a female-specific W chromosome. The avian ZW system is quite the reverse of the well-studied mammalian XY chromosome system, and evolved independently from different autosomal blocs. Despite the different gene content of mammal and bird sex chromosomes, there are many parallels. Genes on the bird Z and the mammal X have both undergone selection for male-advantage functions, and there has been amplification of male-advantage genes and accumulation of LINEs. The bird W and mammal Y have both undergone extensive degradation, but some birds retain early stages and some mammals terminal stages of the process, suggesting that the process is more advanced in mammals. Different sex-determining genes, DMRT1 and SRY, define the ZW and XY systems, but DMRT1 is involved in downstream events in mammals. Birds show strong cell autonomous specification of somatic sex differences in ZZ and ZW tissue, but there is growing evidence for direct X chromosome effects on sexual phenotype in mammals. Dosage compensation in birds appears to be phenotypically and molecularly quite different from X inactivation, being partial and gene-specific, but both systems use tools from the same molecular toolbox and there are some signs that galliform birds represent an early stage in the evolution of a coordinated system. PMID:24599719

  9. The pseudoautosomal region and sex chromosome aneuploidies in domestic species.

    PubMed

    Raudsepp, T; Das, P J; Avila, F; Chowdhary, B P

    2012-01-01

    The pseudoautosomal region (PAR) is a unique and specialized segment on the mammalian sex chromosomes with known functions in male meiosis and fertility. Detailed molecular studies of the region in human and mouse show dramatic differences between the 2 PARs. Recent mapping efforts in horse, dog/cat, cattle/ruminants, pig and alpaca indicate that the PAR also varies in size and gene content between other species. Given that PAR genes escape X inactivation, these differences might critically affect the genetic consequences, such as embryonic survival and postnatal phenotypes of sex chromosome aneuploidies. The aim of this review is to combine the available information about the organization of the PAR in domestic species with the cytogenetic data on sex chromosome aneuploidies. We show that viable XO individuals are relatively frequently found in species with small PARs, such as horses, humans and mice but are rare or absent in species in which the PAR is substantially larger, like in cattle/ruminants, dogs, pigs, and alpacas. No similar correlation can be detected between the PAR size and the X chromosome trisomy in different species. Recent evidence about the likely involvement of PAR genes in placenta formation, early embryonic development and genomic imprinting are presented. PMID:21876343

  10. The sex chromosome complement is an important determinant in obesity and related diseases

    E-print Network

    Link, Jenny Chen

    2015-01-01

    NIH to balance sex in cell and animal studies. Nature. 2014however, animals of both gonadal sexes with XX chromosomesand animal studies, individuals with two X chromosomes also possess ovaries, and XY sex

  11. The advantages of using triple-marker screening for chromosomal abnormalities

    Microsoft Academic Search

    Leonard H. Kellner; Robert R. Weiss; Zeev Weiner; Marsha Neuer; Gregory M. Martin; Harold Schulman; Stanley Lipper

    1995-01-01

    OBJECTIVE: Our purpose was to assess the utility of triple-marker serum screening for chromosomal abnormalities.STUDY DESIGN: Our laboratory received 10,605 samples that were between 15 and 22 weeks' gestation for maternal serum screening of chromosomal abnormalities. Triple-maker maternal serum screening consisted of ?-fetoprotein, human chorionic gonadotropin, and unconjugated estriol in conjunction with maternal age. Women ?35 years old were first

  12. A cytogenetic survey of consecutive liveborn infants-incidence and type of chromosome abnormalities

    Microsoft Academic Search

    Tohru Maeda; Michiko Ohno; Masumi Takada; Yoshikatsu Kato; Masato Nishida; Toshiko Jobo; Hideo Adachi; Akira Taguchi

    1978-01-01

    Summary Cytogenetic investigations have been carried out with particular concern to the frequency of chromosome abnormalities in newborn infants, and this is a preliminary report of data derived from 2,626 consecutive liveborns (1,393 males and 1,233 females) which were collected in one hospital. Of these, 18 infants (0.69%) were found to have a major chromosome abnormality. Eight infants (0.30%) showed

  13. Clinical Implications of Abnormalities of Chromosomes 1 and 13 in Multiple Myeloma

    Microsoft Academic Search

    Yasunori Nakagawa; Masakazu Sawanobori; Hiroshi Amaya; Isao Matsuda; Yasuyuki Inoue; Kenshi Suzuki; Sachiko Hashimoto; Keiko Kanno

    2003-01-01

    Stratification of patients with multiple myeloma according to clinical severity was attempted by chromosomal analysis of 180 bone marrow specimens from 79 patients. The 79 patients were hospitalized and treated between 1994 and 1999. Abnormalities of chromosome 1 were detected at the initial medical examination in 8 (10%) of the 79 patients and were found during follow-up in additional 3

  14. Risk of Chromosome Abnormalities in the Presence of Bilateral or Unilateral Choroid Plexus Cysts

    Microsoft Academic Search

    Artúr Beke; Emese Barakonyi; Zorán Belics; József G. Joó; Ákos Csaba; Csaba Papp; Zoltán Papp

    2008-01-01

    Objectives: To evaluate the rate of chromosome abnormalities in cases of uni- and bilateral choroid plexus cysts (CPCs). Methods: A total of 10,875 ultrasound (US) examinations were performed in the second trimester, and 435 cases with CPC (4%) were found. After genetic counseling, 45 patients decided not to undergo karyotyping. The authors performed a chromosome analysis in 390 cases of

  15. Recent advance in our understanding of the molecular nature of chromosomal abnormalities

    Microsoft Academic Search

    Hiroki Kurahashi; Hasbaira Bolor; Takema Kato; Hiroshi Kogo; Makiko Tsutsumi; Hidehito Inagaki; Tamae Ohye

    2009-01-01

    The completion of the human genome project has enabled researchers to characterize the breakpoints for various chromosomal structural abnormalities including deletions, duplications or translocations. This in turn has shed new light on the molecular mechanisms underlying the onset of gross chromosomal rearrangements. On the other hand, advances in genetic manipulation technologies for various model organisms has increased our knowledge of

  16. [Sex chromosome aberration screening among male psychiatric patients (author's transl)].

    PubMed

    Trixler, M; Kosztolányl, G; Méhes, K

    1976-04-30

    The authors report of sex chromosome aberration screenings among the patients of the male psychiatric department, University Medical School, Pecs. 310 patients were investigated. The X-chromatin was detected in buccal smears with thionin-staining and the Y-chromatin in peripheric blood smears with quinacrin-staining by the help of fluorescentoptical technique. Two Klinefelter-patients and one YY-patient were diagnostized. The Klinefelter-patients were psychopaths and mentally subnormal, the YY-patient was a paranoid schizophrenic. The incidence of Klinefelter syndrome is 0.64%, that of the YY syndrome is 0.32%. Mental relations of sex chromosome aberrations are discussed in detail. PMID:962577

  17. Reversal of an ancient sex chromosome to an autosome in Drosophila.

    PubMed

    Vicoso, Beatriz; Bachtrog, Doris

    2013-07-18

    Although transitions of sex-determination mechanisms are frequent in species with homomorphic sex chromosomes, heteromorphic sex chromosomes are thought to represent a terminal evolutionary stage owing to chromosome-specific adaptations such as dosage compensation or an accumulation of sex-specific mutations. Here we show that an autosome of Drosophila, the dot chromosome, was ancestrally a differentiated X chromosome. We analyse the whole genome of true fruitflies (Tephritidae), flesh flies (Sarcophagidae) and soldier flies (Stratiomyidae) to show that genes located on the dot chromosome of Drosophila are X-linked in outgroup species, whereas Drosophila X-linked genes are autosomal. We date this chromosomal transition to early drosophilid evolution by sequencing the genome of other Drosophilidae. Our results reveal several puzzling aspects of Drosophila dot chromosome biology to be possible remnants of its former life as a sex chromosome, such as its minor feminizing role in sex determination or its targeting by a chromosome-specific regulatory mechanism. We also show that patterns of biased gene expression of the dot chromosome during early embryogenesis, oogenesis and spermatogenesis resemble that of the current X chromosome. Thus, although sex chromosomes are not necessarily evolutionary end points and can revert back to an autosomal inheritance, the highly specialized genome architecture of this former X chromosome suggests that severe fitness costs must be overcome for such a turnover to occur. PMID:23792562

  18. Neo-sex chromosomes in the black muntjac recapitulate incipient evolution of mammalian sex chromosomes

    Microsoft Academic Search

    Qi Zhou; Jun Wang; Ling Huang; Wen-hui Nie; Jin-huan Wang; Yan Liu; Xiang-yi Zhao; Feng-tang Yang; Wen Wang

    2008-01-01

    BACKGROUND: The regular mammalian X and Y chromosomes diverged from each other at least 166 to 148 million years ago, leaving few traces of their early evolution, including degeneration of the Y chromosome and evolution of dosage compensation. RESULTS: We studied the intriguing case of black muntjac, in which a recent X-autosome fusion and a subsequent large autosomal inversion within

  19. Scientists find that chromosomal abnormalities are associated with aging and cancer

    Cancer.gov

    Two new studies have found that large structural abnormalities in chromosomes, some of which have been associated with increased risk of cancer, can be detected in a small fraction of people without a prior history of cancer. The studies found that these alterations in chromosomes appear to increase with age, particularly after the age of 50, and may be associated with an increased risk for cancer. Mosaicism, the type of structural abnormality in chromosomes that is described in these studies, results from a DNA alteration that is present in some of the body's cells but not in others. A person with mosaicism has a mixture of normal and mutated cells.

  20. In multiple myeloma, bone-marrow lymphocytes harboring the same chromosomal abnormalities as autologous plasma cells predict poor survival

    PubMed Central

    Marun, Carina S Debes; Belch, Andrew R; Pilarski, Linda M

    2012-01-01

    Chromosomal abnormalities in plasma cells (PCs) from multiple myeloma (MM) provide a clonal signature to identify malignant cells. BM-lymphocytes from MM aspirates, defined by stringent criteria, were screened for the same chromosomal abnormalities as autologous PCs, including translocations, deletions, and amplifications. For 200 MM patients, we evaluated BM mononuclear cells to identify lymphocytes and autologous PCs on the same slide, followed by interphase fluorescence in situ hybridization to characterize their chromosomal abnormalities. Of all patients having a given chromosomal abnormality(s) in PCs, 45% showed that same abnormality(s) in 2–37% (median = 5%) of BM-lymphocytes. Most translocations, amplifications, and deletions found in MM PCs were also detected in lymphocytes, above the healthy-donor “cut-off.” In patients having chromosomally abnormal CD20? PCs, chromosomally abnormal lymphocytes were found among CD20+ cells confirming them as B cells. Exceptions were amplification of 1q21 or p53 deletion, which characterize PCs but were undetectable in BM-lymphocytes, suggesting that processes leading to these abnormalities may be exclusive to PCs. For a set of 75 patients whose BM-lymphocytes and PCs were analyzed by all six probe sets, 58% of those with abnormal PC also had abnormal BM-lymphocytes harboring from one to five different abnormalities. Confirming the clinical significance of chromosomally abnormal BM-lymphocytes, MM patients having abnormalities in both lymphocytes and PC had significantly worse survival than those with abnormalities only in PC (HR = 2.68). The presence of at least one chromosomal abnormality in BM-lymphocytes appears to have greater clinical significance than particular abnormalities. Chromosomally abnormal BM-lymphocytes correlate with poor outcome and by extrapolation with more aggressive disease. PMID:22495885

  1. Chromosomal Distribution of Cytonuclear Genes in a Dioecious Plant with Sex Chromosomes

    PubMed Central

    Hough, Josh; Ĺgren, J. Arvid; Barrett, Spencer C.H.; Wright, Stephen I.

    2014-01-01

    The coordination between nuclear and organellar genes is essential to many aspects of eukaryotic life, including basic metabolism, energy production, and ultimately, organismal fitness. Although nuclear genes are biparentally inherited, mitochondrial and chloroplast genes are almost exclusively maternally inherited, and this asymmetry may lead to a bias in the chromosomal distribution of nuclear genes whose products act in the mitochondria or chloroplasts. In particular, because X-linked genes have a higher probability of cotransmission with organellar genes (2/3) compared with autosomal genes (1/2), selection for coadaptation has been predicted to lead to an overrepresentation of nuclear-mitochondrial and nuclear-chloroplast genes on the X chromosome relative to autosomes. In contrast, the occurrence of sexually antagonistic organellar mutations might lead to selection for movement of cytonuclear genes from the X chromosome to autosomes to reduce male mutation load. Recent broad-scale comparative studies of N-mt distributions in animals have found evidence for these hypotheses in some species, but not others. Here, we use transcriptome sequences to conduct the first study of the chromosomal distribution of cytonuclear interacting genes in a plant species with sex chromosomes (Rumex hastatulus; Polygonaceae). We found no evidence of under- or overrepresentation of either N-mt or N-cp genes on the X chromosome, and thus no support for either the coadaptation or the sexual-conflict hypothesis. We discuss how our results from a species with recently evolved sex chromosomes fit into an emerging picture of the evolutionary forces governing the chromosomal distribution of nuclear-mitochondrial and nuclear-chloroplast genes. PMID:25193309

  2. Laser isolation of plant sex chromosomes: studies on the DNA composition of the X and Y sex chromosomes of Silene latifolia.

    PubMed

    Scutt, C P; Kamisugi, Y; Sakai, F; Gilmartin, P M

    1997-10-01

    X and Y sex chromosomes from the dioecious plant Silene latifolia (white campion) were isolated from mitotic metaphase chromosome preparations on polyester membranes. Autosomes were ablated using an argon ion laser microbeam and isolated sex chromosomes were then recovered on excised fragments of polyester membrane. Sex chromosome associated DNA sequences were amplified using the degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR) and pools of DOP-PCR products were used to investigate the genomic organization of the S. latifolia sex chromosomes. The chromosomal locations of cloned sex chromosome repeat sequences were analysed by fluorescence in situ hybridization and data complementary to laser ablation studies were obtained by genomic in situ hybridization. In combination, these studies demonstrate that the X and Y sex chromosomes of S. latifolia are of very similar DNA composition and also that they share a significant repetitive DNA content with the autosomes. The evolution of sex chromosomes in Silene is discussed and compared with that in another dioecious species, Rumex acetosa. PMID:9352647

  3. Preservation of the Y transcriptome in a 10-million-year-old plant sex chromosome system.

    PubMed

    Bergero, Roberta; Charlesworth, Deborah

    2011-09-13

    Classical genetic studies discovered loss of genes from the ancient sex chromosome systems of several animals (genetic degeneration), and complete genome sequencing confirms that the heterogametic sex is hemizygous for most sex-linked genes. Genetic degeneration is thought to result from the absence of recombination between the sex chromosome pair (reviewed by [1]) and is very rapid after sex chromosome-autosome fusions in Drosophila [2-4]. Plant sex chromosome systems allow study of the time course of degeneration, because they evolved from a state wholly without sex chromosomes (rather than after a large genome region fused to a preexisting sex chromosome), and, in several taxa, recombination stopped very recently. However, despite increasing genetic and physical mapping of plant nonrecombining sex-determining regions [5-8], it remains very difficult to discover sex-linked genes, and it is unclear whether Y-linked genes are losing full function. We therefore developed a high-throughput method using RNA-Seq to identify sex linkage in Silene latifolia. Recombination suppression between this plant's XY sex chromosome pair started only about 10 million years ago [9]. Our approach identifies several hundred new sex-linked genes, and we show that this young Y chromosome retains many genes, yet these already have slightly reduced gene expression and are accumulating changes likely to reduce protein functions. PMID:21889891

  4. Different autosomes evolved into sex chromosomes in the sister genera of Salix and Populus

    PubMed Central

    Hou, Jing; Ye, Ning; Zhang, Defang; Chen, Yingnan; Fang, Lecheng; Dai, Xiaogang; Yin, Tongming

    2015-01-01

    Willows (Salix) and poplars (Populus) are dioecious plants in Salicaceae family. Sex chromosome in poplar genome was consistently reported to be associated with chromosome XIX. In contrast to poplar, this study revealed that chromosome XV was sex chromosome in willow. Previous studies revealed that both ZZ/ZW and XX/XY sex-determining systems could be present in some species of Populus. In this study, sex of S. suchowensis was found to be determined by the ZW system in which the female was the heterogametic gender. Gene syntenic and collinear comparisons revealed macrosynteny between sex chromosomes and the corresponding autosomes between these two lineages. By contrast, no syntenic segments were found to be shared between poplar's and willow's sex chromosomes. Syntenic analysis also revealed substantial chromosome rearrangements between willow's alternate sex chromatids. Since willow and poplar originate from a common ancestor, we proposed that evolution of autosomes into sex chromosomes in these two lineages occurred after their divergence. Results of this study indicate that sex chromosomes in Salicaceae are still at the early stage of evolutionary divergence. Additionally, this study provided valuable information for better understanding the genetics and evolution of sex chromosome in dioecious plants. PMID:25766834

  5. The evolution of sex chromosomes in the genus Rumex (Polygonaceae): Identification of a new species with heteromorphic sex chromosomes

    Microsoft Academic Search

    Nieves Cuńado; Rafael Navajas-Pérez; Roberto de la Herrán; Carmelo Ruiz Rejón; Manuel Ruiz Rejón; Juan Luis Santos; Manuel A. Garrido-Ramos

    2007-01-01

    The structural features and evolutionary state of the sex chromosomes of the XX\\/XY species of Rumex are unknown. Here, we report a study of the meiotic behaviour of the XY bivalent in Rumex acetosella and R. suffruticosus, a new species which we describe cytogenetically for the first time in this paper, and also that of the XY1Y2 trivalent of R.

  6. Recent gene-capture on the UV sex chromosomes of the moss Ceratodon purpureus.

    PubMed

    McDaniel, Stuart F; Neubig, Kurt M; Payton, Adam C; Quatrano, Ralph S; Cove, David J

    2013-10-01

    Sex chromosomes evolve from ordinary autosomes through the expansion and subsequent degeneration of a region of suppressed recombination that is inherited through one sex. Here we investigate the relative timing of these processes in the UV sex chromosomes of the moss Ceratodon purpureus using molecular population genetic analyses of eight newly discovered sex-linked loci. In this system, recombination is suppressed on both the female-transmitted (U) sex chromosome and the male-transmitted (V) chromosome. Genes on both chromosomes therefore should show the deleterious effects of suppressed recombination and sex-limited transmission, while purifying selection should maintain homologs of genes essential for both sexes on both sex chromosomes. Based on analyses of eight sex-linked loci, we show that the nonrecombining portions of the U and V chromosomes expanded in at least two events (~0.6-1.3 MYA and ~2.8-3.5 MYA), after the divergence of C. purpureus from its dioecious sister species, Trichodon cylindricus and Cheilothela chloropus. Both U- and V-linked copies showed reduced nucleotide diversity and limited population structure, compared to autosomal loci, suggesting that the sex chromosomes experienced more recent selective sweeps that the autosomes. Collectively these results highlight the dynamic nature of gene composition and molecular evolution on nonrecombining portions of the U and V sex chromosomes. PMID:24094335

  7. Comparative analysis of sex chromosomes in Leporinus species (Teleostei, Characiformes) using chromosome painting

    E-print Network

    Parise-Maltempi, Patrícia P.; da Silva, Edson L.; Rens, Willem; Dearden, Frances; O’Brien, Patricia C. M.; Trifonov, Vladimir; Ferguson-Smith, Malcolm A.

    2013-07-03

    involving genetic and/or environmental factors, although temperature-dependent sex determinationLeporinus species (Teleos chromosome painting Patrícia Pasquali Parise-Maltempi1*, Edson Lourenço da Silv Vladimir Trifonov3 and Malcolm A Ferguson-Smith2... Man NK2 (Eppendorf) coupled to a Zeiss Axiovert 40 CFL microscope, with glass needles made with a Nikon puller and sterilized by UV radiation. About 8 chromosomes were separately placed in 9uL DNAse-free ultrapure water and were then amplified using...

  8. Regulation of sex chromosome constitution of somatic and germ cells in the wood lemming

    E-print Network

    Paris-Sud XI, Université de

    Regulation of sex chromosome constitution of somatic and germ cells in the wood lemming A. GROPP K displays certain peculiar features. (a) The sex ratio shows a prevalence of females, and some females produce only female offspring. (b) A conside- rable proportion of the females has XY sex chromosomes

  9. Sex chromosome inactivation in germ cells: emerging roles of DNA damage response pathways

    E-print Network

    Dean, Matthew D.

    REVIEW Sex chromosome inactivation in germ cells: emerging roles of DNA damage response pathways / Accepted: 13 February 2012 / Published online: 2 March 2012 Ó Springer Basel AG 2012 Abstract Sex. Recent progress has revealed the underlying mechanisms of sex chromosome inactivation in male meiosis

  10. Evolutionary History of Silene latifolia Sex Chromosomes Revealed by Genetic Mapping of Four Genes

    Microsoft Academic Search

    Dmitry A. Filatov

    2005-01-01

    The sex chromosomes of dioecious white campion, Silene latifolia (Caryophyllaceae), are of relatively recent origin (10-20 million years), providing a unique opportunity to trace the origin and evolution of sex chromosomes in this genus by comparing closely related Silene species with and without sex chromo- somes. Here I demonstrate that four genes that are X-linked in S. latifolia are also

  11. The role of the sex chromosomes in mammalian germ cell differentiation

    E-print Network

    Paris-Sud XI, Université de

    The role of the sex chromosomes in mammalian germ cell differentiation P. S. BURGOYNE Department and their sex-chromosomal make-up. It is concluded that germ cells in an ovary require two functional X have sterile testes. Ohno (1969) has presented evidence that the genetic content of the sex chromo

  12. Molecular cytogenetic search for cryptic sex chromosomes in painted turtles Chrysemys picta.

    PubMed

    Valenzuela, Nicole; Badenhorst, Daleen; Montiel, Eugenia E; Literman, Robert

    2014-01-01

    Sex determination is triggered by factors ranging from genotypic (GSD) to environmental (ESD), or both GSD + EE (GSD susceptible to environmental effects), and its evolution remains enigmatic. The presence/absence of sex chromosomes purportedly separates species at the ESD end of the continuum from the rest (GSD and GSD + EE) because the evolutionary dynamics of sex chromosomes and autosomes differ. However, studies suggest that turtles with temperature-dependent sex determination (TSD) are cryptically GSD and possess sex chromosomes. Here, we test this hypothesis in painted turtles Chrysemys picta (TSD), using comparative-genome-hybridization (CGH), a technique known to detect morphologically indistinguishable sex chromosomes in other turtles and reptiles. Our results show no evidence for the existence of sex chromosomes in painted turtles. While it remains plausible that cryptic sex chromosomes may exist in TSD turtles that are characterized by minor genetic differences that cannot be detected at the resolution of CGH, previous attempts have failed to identify sex-specific markers. Genomic sequencing should prove useful in providing conclusive evidence in this regard. If such efforts uncover sex chromosomes in TSD turtles, it may reveal the existence of a fundamental constraint for the evolution of a full spectrum of sex determination (from pure GSD to pure TSD) that is predicted theoretically. Finding sex chromosomes in ESD organisms would question whether pure ESD mechanisms exist at all in nature, or whether those systems currently considered pure ESD simply await the characterization of an underlying GSD architecture. PMID:25170556

  13. Rapid de novo evolution of X chromosome dosage compensation in Silene latifolia, a plant with young sex chromosomes.

    PubMed

    Muyle, Aline; Zemp, Niklaus; Deschamps, Clothilde; Mousset, Sylvain; Widmer, Alex; Marais, Gabriel A B

    2012-01-01

    Silene latifolia is a dioecious plant with heteromorphic sex chromosomes that have originated only ?10 million years ago and is a promising model organism to study sex chromosome evolution in plants. Previous work suggests that S. latifolia XY chromosomes have gradually stopped recombining and the Y chromosome is undergoing degeneration as in animal sex chromosomes. However, this work has been limited by the paucity of sex-linked genes available. Here, we used 35 Gb of RNA-seq data from multiple males (XY) and females (XX) of an S. latifolia inbred line to detect sex-linked SNPs and identified more than 1,700 sex-linked contigs (with X-linked and Y-linked alleles). Analyses using known sex-linked and autosomal genes, together with simulations indicate that these newly identified sex-linked contigs are reliable. Using read numbers, we then estimated expression levels of X-linked and Y-linked alleles in males and found an overall trend of reduced expression of Y-linked alleles, consistent with a widespread ongoing degeneration of the S. latifolia Y chromosome. By comparing expression intensities of X-linked alleles in males and females, we found that X-linked allele expression increases as Y-linked allele expression decreases in males, which makes expression of sex-linked contigs similar in both sexes. This phenomenon is known as dosage compensation and has so far only been observed in evolutionary old animal sex chromosome systems. Our results suggest that dosage compensation has evolved in plants and that it can quickly evolve de novo after the origin of sex chromosomes. PMID:22529744

  14. Rapid De Novo Evolution of X Chromosome Dosage Compensation in Silene latifolia, a Plant with Young Sex Chromosomes

    PubMed Central

    Deschamps, Clothilde; Mousset, Sylvain; Widmer, Alex; Marais, Gabriel A. B.

    2012-01-01

    Silene latifolia is a dioecious plant with heteromorphic sex chromosomes that have originated only ?10 million years ago and is a promising model organism to study sex chromosome evolution in plants. Previous work suggests that S. latifolia XY chromosomes have gradually stopped recombining and the Y chromosome is undergoing degeneration as in animal sex chromosomes. However, this work has been limited by the paucity of sex-linked genes available. Here, we used 35 Gb of RNA-seq data from multiple males (XY) and females (XX) of an S. latifolia inbred line to detect sex-linked SNPs and identified more than 1,700 sex-linked contigs (with X-linked and Y-linked alleles). Analyses using known sex-linked and autosomal genes, together with simulations indicate that these newly identified sex-linked contigs are reliable. Using read numbers, we then estimated expression levels of X-linked and Y-linked alleles in males and found an overall trend of reduced expression of Y-linked alleles, consistent with a widespread ongoing degeneration of the S. latifolia Y chromosome. By comparing expression intensities of X-linked alleles in males and females, we found that X-linked allele expression increases as Y-linked allele expression decreases in males, which makes expression of sex-linked contigs similar in both sexes. This phenomenon is known as dosage compensation and has so far only been observed in evolutionary old animal sex chromosome systems. Our results suggest that dosage compensation has evolved in plants and that it can quickly evolve de novo after the origin of sex chromosomes. PMID:22529744

  15. Genetics of dioecy and causal sex chromosomes in plants.

    PubMed

    Kumar, Sushil; Kumari, Renu; Sharma, Vishakha

    2014-04-01

    Dioecy (separate male and female individuals) ensures outcrossing and is more prevalent in animals than in plants. Although it is common in bryophytes and gymnosperms, only 5% of angiosperms are dioecious. In dioecious higher plants, flowers borne on male and female individuals are, respectively deficient in functional gynoecium and androecium. Dioecy is inherited via three sex chromosome systems: XX/XY, XX/X0 and WZ/ZZ, such that XX or WZ is female and XY, X0 or ZZ are males. The XX/XY system generates the rarer XX/X0 and WZ/ZZ systems. An autosome pair begets XY chromosomes. A recessive loss-of-androecium mutation (ana) creates X chromosome and a dominant gynoecium-suppressing (GYS) mutation creates Y chromosome. The ana/ANA and gys/GYS loci are in the sex-determining region (SDR) of the XY pair. Accumulation of inversions, deleterious mutations and repeat elements, especially transposons, in the SDR of Y suppresses recombination between X and Y in SDR, making Y labile and increasingly degenerate and heteromorphic from X. Continued recombination between X and Y in their pseudoautosomal region located at the ends of chromosomal arms allows survival of the degenerated Y and of the species. Dioecy is presumably a component of the evolutionary cycle for the origin of new species. Inbred hermaphrodite species assume dioecy. Later they suffer degenerate-Y-led population regression. Cross-hybridization between such extinguishing species and heterologous species, followed by genome duplication of segregants from hybrids, give rise to new species. PMID:24840848

  16. Genetic and Functional Analysis of DD44, a Sex-Linked Gene From the Dioecious Plant Silene latifolia, Provides Clues to Early Events in Sex Chromosome Evolution

    Microsoft Academic Search

    Richard C. Moore; Olga Kozyreva; Sabine Lebel-Hardenack; Jiri Siroky; Roman Hobza; Boris Vyskot; Sarah R. Grant

    Silene latifolia is a dioecious plant with heteromorphic sex chromosomes. The sex chromosomes of S. latifolia provide an opportunity to study the early events in sex chromosome evolution because of their relatively recent emergence. In this article, we present the genetic and physical mapping, expression analysis, and molecular evolutionary analysis of a sex-linked gene from S. latifolia, DD44 (Differential Display

  17. Consistent chromosome abnormalities including double minutes (dms) in adenocarcinoma of the pancreas

    SciTech Connect

    Griffin, C.A.; Morsberger, L.; Ellingham, T. [Johns Hopkins School of Medicine, Chicago, IL (United States)] [and others

    1994-09-01

    Little is known about the somatic genetic changes which characterize pancreatic adenocarcinoma (PA), and identification of acquired genomic alterations would further our understanding of the biology of this neoplasm. We have studied 62 primary specimens of PA using classical and FISH methods. Clonally abnormal karyotypes were observed in 44 neoplasms. Karyotypes were generally complex (greater than 3 abnormalities) including both numerical and structural chromosome changes. Many tumors contained at least one marker chromosome. The most frequent whole chromosomal gains were chromosomes 20 (7 tumors) and 7 (5 tumors). Losses were much more frequent: chromosome 18 was lost in 22 tumors, followed by chromosomes 13 (15 tumors), 12 (13 tumors), and 6 (12 tumors). Structural abnormalities were common. 200 chromosome breakpoints were identified. Excluding Robertsonian translocations, chromosomal arms most frequently involved were 6q (12 chromosomes), 1p and 3p (10 each), 11p and 17p (9 each), 1q (8), 8p and 19q (7 each). Of particular interest, we found dms in 6 cases. These represent the first PAs with cytogenetic evidence of gene amplification, and are under investigation using chromosome microdissection. To begin to define the smallest region of 6q which is deleted, 5 tumors with 6q deletions were hybridized with a biotin-labeled probe, made by microdissection of 6q24-qter. Loss of one copy of this region was verified in 4/5 tumors; additional probes are being made. Our results are similar to those of 34 other reported PAs, and the combined data suggest that gains of chromosomes 7 and 20 and deletions and rearrangements of 1p and 6q may be particularly important in the biology of adenocarcinoma of the pancreas.

  18. Identification of chromosome abnormalities in the horse using a panel of chromosome-specific painting probes generated by microdissection.

    PubMed

    Bugno, Monika; S?ota, Ewa; Pie?kowska-Schelling, Aldona; Schelling, Claude

    2009-09-01

    Fluorescent in situ hybridisation (FISH) using a panel of molecular probes for all chromosome pairs obtained by chromosome microdissection of the domestic horse ( Equus caballus ) was used to diagnose karyotype abnormalities in 35 horses (32 mares, 2 stallions and 1 intersex), which were selected for the study due to infertility (23 horses), reduced fertility (10 horses) and developmental anomalies (2 horses). The use of the FISH technique with probes for each horse chromosome pair enabled the diagnosis of many different chromosome aberrations in this population. Among the horses analysed, 21 animals had normal karyotype - 64,XX (19 mares) and 64,XY (2 stallions). Fourteen animals, constituting 40% of the population studied, showed the following chromosome abnormalities: 63,X (1 mare); 63,X/64,XX (6 mares); 63,X/64,XX/65,XXX (3 mares); 63,X/65,XXX (1 mare); 64,XX/65,XX+Xp (1 mare); 63,X/64,XX/65,XX+Xq (1 mare), and 63,X/64,XX/65,XX+delY (1 intersex). When only the mares studied because of complete infertility were taken into consideration, this proportion exceeded 56%. Due to the increased frequency of the above-mentioned aberrations in the mosaic form of two or more lines, it was necessary to analyse a large number (100-300) of metaphase spreads. The use of specific molecular probes obtained by chromosome microdissection made these diagnoses much easier. PMID:19635709

  19. Systematic review of accuracy of prenatal diagnosis for abnormal chromosome diseases by microarray technology.

    PubMed

    Xu, H B; Yang, H; Liu, G; Chen, H

    2014-01-01

    The accuracy of prenatal diagnosis for abnormal chromosome diseases by chromosome microarray technology and karyotyping were compared. A literature search was carried out in the MEDLINE database with the keywords "chromosome" and "karyotype" and "genetic testing" and "prenatal diagnosis" and "oligonucleotide array sequence". The studies obtained were filtered by using the QUADAS tool, and studies conforming to the quality standard were fully analyzed. There was one paper conforming to the QUADAS standards including 4406 gravidas with adaptability syndromes of prenatal diagnosis including elderly parturient women, abnormal structure by type-B ultrasound, and other abnormalities. Microarray technology yielded successful diagnoses in 4340 cases (98.8%), and there was no need for tissue culture in 87.9% of the samples. All aneuploids and non-parallel translocations in 4282 cases of non-chimera identified by karyotyping could be detected using microarray analysis technology, whereas parallel translocations and fetal triploids could not be detected by microarray analysis technology. In the samples with normal karyotyping results, type-B ultrasound showed that 6% of chromosomal deficiencies or chromosome duplications could be detected by microarray technology, and the same abnormal chromosomes were detected in 1.7% of elderly parturient women and samples with positive serology screening results. In the prenatal diagnosis test, compared with karyotyping, microarray technology could identify the extra cell genetic information with clinical significance, aneuploids, and non-parallel translocations; however, its disadvantage is that it could not identify parallel translocations and triploids. PMID:25366803

  20. Gonadal- and sex-chromosome-dependent sex differences in the circadian system.

    PubMed

    Kuljis, Dika A; Loh, Dawn H; Truong, Danny; Vosko, Andrew M; Ong, Margaret L; McClusky, Rebecca; Arnold, Arthur P; Colwell, Christopher S

    2013-04-01

    Compelling reasons to study the role of sex in the circadian system include the higher rates of sleep disorders in women than in men and evidence that sex steroids modulate circadian control of locomotor activity. To address the issue of sex differences in the circadian system, we examined daily and circadian rhythms in wheel-running activity, electrical activity within the suprachiasmatic nucleus, and PER2::LUC-driven bioluminescence of gonadally-intact adult male and female C57BL/6J mice. We observed greater precision of activity onset in 12-hour light, 12-hour dark cycle for male mice, longer activity duration in 24 hours of constant darkness for female mice, and phase-delayed PER2::LUC bioluminescence rhythm in female pituitary and liver. Next, in order to investigate whether sex differences in behavior are sex chromosome or gonadal sex dependent, we used the 4 core genotypes (FCG) mouse model, in which sex chromosome complement is independent of gonadal phenotype. Gonadal males had more androgen receptor expression in the suprachiasmatic nucleus and behaviorally reduced photic phase shift response compared with gonadal female FCG mice. Removal of circulating gonadal hormones in adults, to test activational vs organizational effects of sex revealed that XX animals have longer activity duration than XY animals regardless of gonadal phenotype. Additionally, we observed that the activational effects of gonadal hormones were more important for regulating activity levels in gonadal male mice than in gonadal female FCG mice. Taken together, sex differences in the circadian rhythms of activity, neuronal physiology, and gene expression were subtle but provide important clues for understanding the pathophysiology of the circadian system. PMID:23439698

  1. A new FISH assay to simultaneously detect structural and numerical chromosomal abnormalities in mouse sperm.

    PubMed

    Hill, Francesca S; Marchetti, Francesco; Liechty, Melissa; Bishop, Jack; Hozier, John; Wyrobek, Andrew J

    2003-10-01

    De novo aberrations in chromosome structure represent important categories of paternally transmitted genetic damage. Unlike numerical abnormalities, the majority of de novo structural aberrations among human offspring are of paternal origin. We report the development of a three-color fluorescence in situ hybridization (FISH) assay (CT8) to detect mouse sperm carrying structural and numerical chromosomal abnormalities. The CT8 assay uses DNA probes for the centromeric and telomeric regions of chromosome 2, and a probe for the subcentromeric region of chromosome 8. The CT8 assay was used to measure the frequencies of sperm carrying certain structural aberrations involving chromosome 2 (del2ter, dup2ter, del2cen, dup2cen), disomy 2, disomy 8, and sperm diploidy. Analysis of approximately 80,000 sperm from eight B6C3F1 mice revealed an average baseline frequency of 2.5 per 10,000 sperm carrying partial duplications and deletions of chromosome 2. Extrapolated to the entire haploid genome, approximately 0.4% of mouse sperm are estimated to carry structural chromosomal aberrations, which is more than fivefold lower than the spontaneous frequencies of sperm with chromosome structural aberrations in man. We validated the CT8 assay by comparing the frequencies of abnormal segregants in sperm of T(2;14) translocation carriers detected by this assay against those detected by chromosome painting cytogenetic analysis of meiosis II spermatocytes. The CT8 sperm FISH assay is a promising method for detecting structural chromosome aberrations in mouse sperm with widespread applications in genetics, physiology, and genetic toxicology. PMID:12950105

  2. MMPI Profiles of Males with Abnormal Sex Chromosome Complements

    ERIC Educational Resources Information Center

    Rosen, M.; And Others

    1971-01-01

    Nine males with Klinefelter's syndrome (XXY) and seven XYY males, located primarily in prisons and psychiatric hospitals, were administered the Minnesota Multiphasic Personality Inventory. (Author/KW)

  3. Unequal mitotic sister chromatid exchange: A rare mechanism for chromosomal abnormality resulting in duplication/deletion of chromosome 7q

    SciTech Connect

    Eydoux, P.; Ortenberg, J.; Chalifoux, N. [Montreal Children`s Hospital, Quebec (Canada)

    1994-09-01

    We report a case of unequal mitotic chromatid exchange, which has rarely been reported as a mechanism for microscopic chromosomal anomalies. The proposita was born at 40 weeks, after an uneventful pregnancy, of parents with a negative family history. The baby was small for gestational age and had dysmorphic features, including scaphocephaly, bilateral epicanthal folds and palpebral ptosis, mild hypertelorism, hypoplasia of orbital contours, right coloboma, bulbous prominent nose, retrognathism, downturned mouth, low set posteriorly rotated ears, tapering of the limbs. bilateral Sydney creases. At 5 months, she was under the 5th percentile for height, weight and head circumference, and had a mild developmental delay. The karyotype showed an abnormality of chromosome 7 in all cells, half with a duplication and half with a deletion of the same region; 46,XX,del(7)(q33{yields}q34)/46,XX,dup(7)(q33{yields}q34). This chromosomal abnormality could be explained by an unequal chromatid exchange occuring in the first mitosis of the embryo. To our knowledge, only one such human microscopic abnormality, involving chromosome Y, has been reported to date. This type of genetic unbalance could be missed by molecular techniques.

  4. Sex Chromosome Turnover Contributes to Genomic Divergence between Incipient Stickleback Species

    PubMed Central

    Yoshida, Kohta; Makino, Takashi; Yamaguchi, Katsushi; Shigenobu, Shuji; Hasebe, Mitsuyasu; Kawata, Masakado; Kume, Manabu; Mori, Seiichi; Peichel, Catherine L.; Toyoda, Atsushi; Fujiyama, Asao; Kitano, Jun

    2014-01-01

    Sex chromosomes turn over rapidly in some taxonomic groups, where closely related species have different sex chromosomes. Although there are many examples of sex chromosome turnover, we know little about the functional roles of sex chromosome turnover in phenotypic diversification and genomic evolution. The sympatric pair of Japanese threespine stickleback (Gasterosteus aculeatus) provides an excellent system to address these questions: the Japan Sea species has a neo-sex chromosome system resulting from a fusion between an ancestral Y chromosome and an autosome, while the sympatric Pacific Ocean species has a simple XY sex chromosome system. Furthermore, previous quantitative trait locus (QTL) mapping demonstrated that the Japan Sea neo-X chromosome contributes to phenotypic divergence and reproductive isolation between these sympatric species. To investigate the genomic basis for the accumulation of genes important for speciation on the neo-X chromosome, we conducted whole genome sequencing of males and females of both the Japan Sea and the Pacific Ocean species. No substantial degeneration has yet occurred on the neo-Y chromosome, but the nucleotide sequence of the neo-X and the neo-Y has started to diverge, particularly at regions near the fusion. The neo-sex chromosomes also harbor an excess of genes with sex-biased expression. Furthermore, genes on the neo-X chromosome showed higher non-synonymous substitution rates than autosomal genes in the Japan Sea lineage. Genomic regions of higher sequence divergence between species, genes with divergent expression between species, and QTL for inter-species phenotypic differences were found not only at the regions near the fusion site, but also at other regions along the neo-X chromosome. Neo-sex chromosomes can therefore accumulate substitutions causing species differences even in the absence of substantial neo-Y degeneration. PMID:24625862

  5. Crown-rump length in chromosomally abnormal fetuses at 10 to 13 weeks' gestation

    Microsoft Academic Search

    Peter Kuhn; Maria de Lourdes Brizot; Pranaw P. Pandya; Rosalinde J. Snijders; Kypros H. Nicolaides

    1995-01-01

    OBJECTIVE: Our purpose was to investigate whether fetuses with aneuploidies demonstrate evidence of growth retardation during the first trimester.STUDY DESIGN: This was a retrospective, cross-sectional study of singleton pregnancies undergoing fetal karyotyping at 10 to 13 weeks' gestation. Measurements of crown-rump length in 135 chromosomally abnormal fetuses were compared with those in 700 chromosomally normal fetuses.RESULTS: The median crown-rump length

  6. Retinoid Pathway and Congenital Diaphragmatic Hernia: Hypothesis from the Analysis of Chromosomal Abnormalities

    Microsoft Academic Search

    Carole Goumy; Laetitia Gouas; Geoffroy Marceau; Karen Coste; Lauren Veronese; Denis Gallot; Vincent Sapin; Philippe Vago; Andrei Tchirkov

    2010-01-01

    Background\\/Objectives: Although there is strong evidence implicating genetic factors in congenital diaphragmatic hernia (CDH) pathogenesis, few causal genes have been identified. Many studies suggest that early disruption of the retinoid signaling pathway during gestation may contribute to CDH etiology. Chromosome abnormalities are detected in 10–20% of CDH cases. Chromosomal regions that are involved in balanced translocations or are recurrently deleted

  7. Multiple sex-chromosome mechanisms and polyploidy in animals

    Microsoft Academic Search

    Elisabeth Goldschmidt

    1953-01-01

    Summary  \\u000a \\u000a \\u000a \\u000a 1. \\u000a The possible connexion between multiple sex-chromosome mechanisms and polyploidy in Forficulina,Gryllotalpa spp., Pentatomidae and Mantidae is discussed.\\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a Forficula smyrnensis Serv. (2n = 21) has an X1X2Y mechanism and thus belongs to the group of Forficulina which combine tetraploidy with a multiple sex mechanism.\\u000a \\u000a \\u000a \\u000a 3. \\u000a It is shown that an X1X2Y mechanism might arise as the direct result

  8. Ultrastructural characterization of the sex chromosomes during spermatogenesis of spiders having holocentric chromosomes and a long diffuse stage.

    PubMed

    Benavente, R; Wettstein, R

    1980-01-01

    An ultrastructural study has been made of spermatogenesis in two species of primitive spiders having holocentric chromosomes (Dysdera crocata, male X0 and Sergestria florentia X1X2O). Analysis of the meiotic prophase shows a scarcity or absence of typical leptotene to pachytene stages. Only in D. crocata have synaptonemal complex (SC) remnants been seen, and these occurred in nuclei with an extreme chromatin decondensation. In both species typical early prophase stages have been replaced by nuclei lacking SC and with their chromatin almost completely decondensed, constituting a long and well-defined diffuse stage. Only nucleoli and the condensed sex chromosomes can be identified. - In S. florentina paired non-homologous sex chromosomes lack a junction lamina and thus clearly differ from the sex chromosomes of more evolved spiders with an X1X20 male sex determination mechanism. In the same species, sex chromosomes can be recognized during metaphase I due to their special structural details, while in D. crocata the X chromosome is not distinguishable from the autosomes at this stage. - The diffuse stage and particularly the structural characteristics of the sex chromosomes during meiotic prophase are reviewed and discussed in relation to the meiotic process in other arachnid goups. PMID:7371451

  9. Chromosomal abnormalities in human sperm: Comparisons among four healthy men

    Microsoft Academic Search

    B. Brandriff; L. Gordon; L. Ashworth; G. Watchmaker; A. Carrano; A. Wyrobek

    1984-01-01

    We have used the human-sperm\\/hamster-egg system to compare the frequencies of structural and numerical chromosomal aberrations in 909 sperm karyotypes from four normal healthy men. The frequency of structural aberrations was 1.3, 4.8, 9.0, and 10.4% respectively in the four donors. Certain specific breakpoints were seen twice or even three times in three of the donors. The incidence of aneuploidy

  10. Sex Chromosomes and Karyotype of the (Nearly) Mythical Creature, the Gila Monster, Heloderma suspectum (Squamata: Helodermatidae)

    PubMed Central

    Pokorná, Martina Johnson; Rovatsos, Michail; Kratochvíl, Lukáš

    2014-01-01

    A wide variety of sex determination systems exist among squamate reptiles. They can therefore serve as an important model for studies of evolutionary transitions among particular sex determination systems. However, we still have only a limited knowledge of sex determination in certain important lineages of squamates. In this respect, one of the most understudied groups is the family Helodermatidae (Anguimorpha) encompassing the only two venomous species of lizards which are potentially lethal to human beings. We uncovered homomorphic ZZ/ZW sex chromosomes in the Gila monster (Heloderma suspectum) with a highly heterochromatic W chromosome. The sex chromosomes are morphologically similar to the ZZ/ZW sex chromosomes of monitor lizards (Varanidae). If the sex chromosomes of helodermatids and varanids are homologous, female heterogamety may be ancestral for the whole Anguimorpha group. Moreover, we found that the karyotype of the Gila monster consists of 2n?=?36 chromosomes (14 larger metacentric chromosomes and 22 acrocentric microchromosomes). 2n?=?36 is the widely distributed chromosomal number among squamates. In his pioneering works representing the only previous cytogenetic examination of the family Helodermatidae, Matthey reported the karyotype as 2n?=?38 and suggested a different chromosomal morphology for this species. We believe that this was probably erroneously. We also discovered a strong accumulation of telomeric sequences on several pairs of microchromosomes in the Gila monster, which is a trait documented relatively rarely in vertebrates. These new data fill an important gap in our understanding of the sex determination and karyotype evolution of squamates. PMID:25119263

  11. [Role of transposons in origin and evolution of plant XY sex chromosomes].

    PubMed

    Shufen, Li; Sha, Li; Chuanliang, Deng; Longdou, Lu; Wujun, Gao

    2015-02-01

    The XY sex-determination system is crucial for plant reproduction. However, little is known about the mechanism of the origin and evolution of the XY sex chromosomes. It has been believed that a pair of autosomes is evolved to produce young sex chromosomes (neo-X chromosome and neo-Y chromosome) by loss of function or gain of function mutation, which influences the development of pistil or stamen. With the aggravation of the recombination suppression between neo-X and neo-Y and consequent expanding of the non-recombination region, the proto-sex chromosomes were finally developed to heteromorphic sex chromosomes. Accumulation of repetitive sequences and DNA methylation were probably involved in this process. Transposons, as the most abundant repetitive sequences in the genome, might be the initial motivation factors for the evolution of sex chromosome. Moreover, transposons may also increase heterochromatin expansion and recombination suppression of sex chromosome by local epigenetics modification. In this review, we summarize the function of transposon accumulation and the relationship between transposon and heterochromatization in the evolution of plant sex chromosome. PMID:25665642

  12. Ring chromosome 5 associated with severe growth retardation as the sole major physical abnormality

    SciTech Connect

    Migliori, M.V.; Pettinari, A. [Ospedale Salesi, Ancona (Italy); Cherubini, V.; Bartolotta, E.; Pecora, R. [Ospedale S. Lucia, Recanati (Italy)

    1994-01-01

    The authors report on a case of ring chromosome 5 in a 36-month-old girl with severe growth retardation, clinodactyly, mild psychological abnormalities, and normal facial appearance. Endocrine tests showed partial growth hormone deficiency. Cytogenetic investigation failed to demonstrate any apparent microscopic deletion of either the short or long arm of chromosome 5 as a consequence of ring formation. In 12% of cells examined, the ring was either absent or present in multiple copies. Only 3 previous cases of ring chromosome 5 have been reported in association with short stature of prenatal onset and minor anomalies, without mental retardation. 12 refs., 3 figs.

  13. The origin and evolution of vertebrate sex chromosomes and dosage compensation

    Microsoft Academic Search

    A M Livernois; J A M Graves; P D Waters

    2012-01-01

    In mammals, birds, snakes and many lizards and fish, sex is determined genetically (either male XY heterogamy or female ZW heterogamy), whereas in alligators, and in many reptiles and turtles, the temperature at which eggs are incubated determines sex. Evidently, different sex-determining systems (and sex chromosome pairs) have evolved independently in different vertebrate lineages. Homology shared by Xs and Ys

  14. Isodicentric Y chromosomes in Egyptian patients with disorders of sex development (DSD).

    PubMed

    Mekkawy, Mona; Kamel, Alaa; El-Ruby, Mona; Mohamed, Amal; Essawi, Mona; Soliman, Hala; Dessouky, Nabil; Shehab, Marwa; Mazen, Inas

    2012-07-01

    Isodicentric chromosome formation is the most common structural abnormality of the Y chromosome. As dicentrics are mitotically unstable, they are subsequently lost during cell division resulting in mosaicism with a 45,X cell line. We report on six patients with variable signs of disorders of sex development (DSD) including ambiguous genitalia, short stature, primary amenorrhea, and male infertility with azoospermia. Cytogenetic studies showed the presence of a sex chromosome marker in all patients; associated with a 45,X cell line in five of them. Fluorescence in situ hybridization (FISH) technique was used to determine the structure and the breakage sites of the markers that all proved to be isodicentric Y chromosomes. Three patients, were found to have similar breakpoints: idic Y(qter? p11.32:: p11.32? qter), two of them presented with ambiguous genitalia and were found to have ovotesticular DSD, while the third presented with short stature and hypomelanosis of Ito. One female patient presenting with primary amenorrhea, Turner manifestations and ambiguous genitalia revealed the breakpoint: idic Y (pter?q11.1::q11.1?pter). The same breakpoint was detected in a male with azoospermia but in non-mosaic form. An infant with ambiguous genitalia and mixed gonadal dysgenesis (MGD) had the breakpoint at Yq11.2: idic Y(pter?q11.2::q11.2?pter). SRY signals were detected in all patients. Sequencing of the SRY gene was carried out for three patients with normal results. This study emphasizes the importance of FISH analysis in the diagnosis of patients with DSD as well as the establishment of the relationship between phenotype and karyotype. PMID:22628100

  15. Sex-determining mechanisms in insects based on imprinting and elimination of chromosomes.

    PubMed

    Sánchez, L

    2014-01-01

    As a rule, the sex of an individual is fixed at fertilization, and the chromosomal constitution of the zygote is a direct consequence of the chromosomal constitution of the gametes. However, there are cases in which the chromosomal differences determining sex are brought about by elimination or inactivation of chromosomes in the embryo. In Sciaridae insects, all zygotes start with the XXX constitution; the loss of either 1 or 2 X chromosomes determines whether the zygote becomes XX (female) or X0 (male). In Cecydomyiidae and Collembola insects, all zygotes start with the XXXX constitution. If the embryo does not eliminate any X chromosome, this remains XXXX and develops as female, whereas if 2 X chromosomes are eliminated, the embryo becomes XX0 and develops as a male. In the coccids (scale insects), the chromosomal differences between the sexes result from either the elimination or the heterochromatinization (inactivation) of half of the chromosomes giving rise to haploid males and diploid females. The chromosomes that are eliminated or inactivated are those inherited from the father. Therefore, in the formation of the sex-determining chromosomal signal in those insects, a marking ('imprinting') process must occur in one of the parents, which determines that the chromosomes to be eliminated or inactivated are of paternal origin. In this article, the sex determination mechanism of these insects and the associated imprinting process are reviewed. PMID:24296911

  16. Chromosome abnormalities in diffuse large B-cell lymphomas: analysis of 231 Chinese patients.

    PubMed

    Zhao, Xiaoli; Fan, Rong; Lin, Guowei; Wang, Xiaoqin

    2013-09-01

    Genome instability is a hallmark of cancer. Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma with high levels of chromosomal aberrations. The purpose of this study was to characterize chromosomal aberrations in Chinese DLBCL patients and to compare chromosomal abnormalities between germinal centre B-cell-like (GCB) and non-GCB subgroups. Fluorescence in situ hybridization, G-band cytogenetics and immunohistochemistry were performed in 231 cases of de novo DLBCL. We demonstrated that the rate of abnormal and complex karyotypes was 89.1% (139/156) and 92.8% (129/139), respectively. We found a total of 490 structural chromosomal aberrations, including 96 frequent and recurring structural alterations. Most importantly, we identified several rare or novel chromosomal alterations: eight gains (5, 13, 14q, 17, 19p, 20, 21p, Y), one loss (21) and three recurrent translocations [t(7;15)(q22;q22), t(3;20)(p24;q13.1), t(2;3)(q21;q25)]. Moreover, the frequent recurrent genomic imbalance between GCB and non-GCB subgroups was different. Finally, we discovered two cases of concurrent IGH-BCL6 and MYC rearrangements. The rate of abnormal karyotypes in DLBCL patients of Chinese descent was similar to that of Western countries, but some common karyotypes were different, as were the abnormal karyotypes of GCB and non-GCB subgroups. Our discovery of rare and novel abnormal karyotypes may represent unique chromosomal alterations in Chinese DLBCL patients. PMID:23135954

  17. Chromosomal abnormalities in Hodgkin's disease are not restricted to Hodgkin/Reed-Sternberg cells.

    PubMed

    Jansen, M P; Hopman, A H; Haesevoets, A M; Gennotte, I A; Bot, F J; Arends, J W; Ramaekers, F C; Schouten, H C

    1998-06-01

    Hodgkin and Reed-Sternberg cells are considered to represent the malignant fraction in Hodgkin's disease. Several studies have shown that the Hodgkin and Reed-Sternberg cells are chromosomally abnormal, but genetic data about the morphologically normal cell population in Hodgkin's disease are very limited. This latter cell population has therefore been examined for chromosomal aberrations, using the in situ hybridization (ISH) procedure, making use of DNA probes for chromosomes 1, 7, 8, 9, 11, 12, 15, 17, and 18. Nuclei were isolated from freshly frozen (10 cases) and paraffin-embedded (16 cases) biopsy samples and 1000 nuclei per case were evaluated. The cases of Hodgkin's disease were compared with reactive lymph nodes, which show aberrant chromosome copy numbers in less than 1 per cent of the cells. Using strict scoring criteria, nuclei in the tumour were found to show an abnormal genotype, in the range of 1-12 per cent, with trisomies occurring most frequently. No characteristic numerical chromosome abnormality was observed. ISH on 4 microns thick paraffin sections of six cases of Hodgkin's disease revealed numerical aberrations for chromosome 1 in cells which appeared to be morphologically normal. The genomically abnormal nuclei did not differ in morphology or size from the nuclei of morphologically normal cells, but differed considerably in size when compared with the nuclei of Hodgkin/Reed-Sternberg cells after the ISH procedure. Three of these six cases revealed a population of apparently normal cells with an aberrant copy number which differed notably from the fraction observed in reactive lymph nodes. It is concluded, therefore, that a subset of morphologically normal cells, next to the Hodgkin/Reed-Sternberg cells, are chromosomally aberrant and may participate in the malignant cell fraction of Hodgkin's disease. PMID:9713340

  18. Clonal chromosomal abnormalities in congenital bile duct dilatation (Caroli's disease)

    PubMed Central

    Parada, L; Hallen, M; Hagerstrand, I; Tranberg, K; Johansson, B

    1999-01-01

    BACKGROUND—Caroli's disease is a rare congenital disorder characterised by cystic dilatation of the intrahepatic bile ducts and an increased risk of cholangiocellular carcinoma. The cause is unknown, but occasional familial clustering suggests that some cases are inherited, in particular when occurring in association with polycystic kidney disease and germline PKD1 gene mutations. To date, no gene responsible for familial isolated Caroli's disease has been identified, and no genetic investigations of liver tissue from patients with Caroli's disease have been reported.?PATIENT/METHOD—A liver biopsy specimen from a patient with isolated Caroli's disease, without any signs of cholangiocellular carcinoma, was short term cultured and cytogenetically investigated after G banding with Wright's stain.?RESULT—Cytogenetic analysis disclosed the karyotype 45-47,XX,der(3)t(3;8)(p23;q13), +2mar[cp6]/46,XX[18].?CONCLUSIONS—The finding of an unbalanced translocation between chromosomes 3 and 8 suggests that loss of distal 3p and/or gain of 8q is of pathogenetic importance in Caroli's disease. Alternatively, structural rearrangements of genes located in 3p23 and 8q13 may be of the essence. These chromosomal breakpoints may also pinpoint the location of genes involved in inherited forms of Caroli's disease not associated with polycystic kidney disease.???Keywords: Caroli's disease; bile duct; cytogenetics PMID:10517920

  19. Abnormal chromosome complement resulting from a familial inversion of chromosome 2.

    PubMed Central

    Richter, S; Lockwood, B; Lockwood, D; Allanson, J

    1989-01-01

    It has been suggested that pericentric inversions of chromosome 2 increase the risk for spontaneous abortion but do not increase the risk for unbalanced recombinant offspring. We report our experience of a familial pericentric inversion of chromosome 2 resulting in two unbalanced recombinant offspring. Both subjects have 46,XX,rec(2),dup q,inv(2)(p25q35). Images PMID:2479747

  20. Clear cell sarcoma of the kidney with calcification and a novel chromosomal abnormality: a case report.

    PubMed

    Kato, Masaya; Sato, Yuya; Fukushima, Keitaro; Okuya, Mayuko; Kurosawa, Hidemitsu; Kuwashima, Shigeko; Honma, Koichi; Okamoto, Kentaro; Tsuchioka, Takashi; Arisaka, Osamu

    2015-01-01

    A 9-year-old male presented with a renal tumor that showed a cystic structure with calcification on computed tomography. A pathological analysis of the resected tumor suggested clear cell sarcoma of the kidney (CCSK). Thus, this patient suffered atypical CCSK with significant calcification and gross necrosis. A novel chromosomal abnormality was also identified in the tumor. PMID:26182914

  1. The Evolutionary Tempo of Sex Chromosome Degradation in Carica papaya.

    PubMed

    Wu, Meng; Moore, Richard C

    2015-06-01

    Genes on non-recombining heterogametic sex chromosomes may degrade over time through the irreversible accumulation of deleterious mutations. In papaya, the non-recombining male-specific region of the Y (MSY) consists of two evolutionary strata corresponding to chromosomal inversions occurring approximately 7.0 and 1.9 MYA. The step-wise recombination suppression between the papaya X and Y allows for a temporal examination of the degeneration progress of the young Y chromosome. Comparative evolutionary analyses of 55 X/Y gene pairs showed that Y-linked genes have more unfavorable substitutions than X-linked genes. However, this asymmetric evolutionary pattern is confined to the oldest stratum, and is only observed when recently evolved pseudogenes are included in the analysis, indicating a slow degeneration tempo of the papaya Y chromosome. Population genetic analyses of coding sequence variation of six Y-linked focal loci in the oldest evolutionary stratum detected an excess of nonsynonymous polymorphism and reduced codon bias relative to autosomal loci. However, this pattern was also observed for corresponding X-linked loci. Both the MSY and its corresponding X-specific region are pericentromeric where recombination has been shown to be greatly reduced. Like the MSY region, overall selective efficacy on the X-specific region may be reduced due to the interference of selective forces between highly linked loci, or the Hill-Robertson effect, that is accentuated in regions of low or suppressed recombination. Thus, a pattern of gene decay on the X-specific region may be explained by relaxed purifying selection and widespread genetic hitchhiking due to its pericentromeric location. PMID:25987354

  2. Loss of sex chromosomes in the hematopoietic disorders: Questions, concerns and data interpretation

    SciTech Connect

    Slovak, M.L. [City of Hope National Medical Center, Duarte, CA (United States)

    1994-09-01

    The significance of sex chromosome aberrations in the hematopoietic disorders has not yet been defined. Interpretive problems stem from (1) the loss of a sex chromosome associated with aging, (2) sex chromosome loss as the sole aberration in leukemia is rare, (3) random -(X or Y) is observed frequently in bone marrow samples, and (4) constitutional sex chromosome anomalies must be ruled out in cancer and follow-up may not be possible. The COH database identified 41 patients (pts) with sex chromosome loss. Loss of a sex chromosome was common in myeloid disorders (21/41). In t(8;21) leukemia (n=10), -(X or Y) was a common secondary karyotypic change. Additionally, -Y was associated with clonal evolution in 2 Ph + CML pts. In 2 elderly pts with myeloid disorders, -(X or Y) was observed in complex karyotypes with dmins; however, in the lymphoproliferative disorders -(X or Y) was noted in elderly pts without apparent pathogenetic significance. Three pts had constitutional sex chromosome aberrations: CML in 45,X; ALL in 47, XXY; and RAEB-IT in mos45,X/46,XX. In the mos45,X/46,XX pt, the leukemic clone was associated with the 45,X line without other karyotypic changes. Non-clonal aberrations were observed in 11 cases; in 3 cases these non-clonal losses were observed in serial samples. In a sex-mismatched BMT case, -(X or Y) in 4 cells was one of the first pathogenetic signs of leukemia relapse. These data suggest (1) interpretation of sex chromosome loss in leukemia must be made with caution and after a baseline sample, (2) non-clonal aberrations should be recorded, and (3) -(X or Y) appears to have pathogenetic significance in the myeloid disorders. Multi-institutional studies are needed to define (1) the incidence of leukemia in pts with constitutional sex chromosome anomalies and (2) the incidence and significance of sex chromosome aberrations as the primary (sole) cytogenetic aberration in leukemia.

  3. Effects of Sex Chromosome Aneuploidies on Brain Development: Evidence from Neuroimaging Studies

    ERIC Educational Resources Information Center

    Lenroot, Rhoshel K.; Lee, Nancy Raitano; Giedd, Jay N.

    2009-01-01

    Variation in the number of sex chromosomes is a relatively common genetic condition, affecting as many as 1/400 individuals. The sex chromosome aneuploidies (SCAs) are associated with characteristic behavioral and cognitive phenotypes, although the degree to which specific individuals are affected can fall within a wide range. Understanding the…

  4. The Mitotic Chromosomes in Xenopus laevis (Daudin): Normal, Sex Reversed and Female WW

    Microsoft Academic Search

    K. Mikamo; E. Witschi

    1966-01-01

    A chromosome study in Xenopus lae&ypsilon;is with five of the six possible male and female sex combinations of the ZZ, ZW and WW genie constitutions furnishes no visible evidence of sex chromosome dimorphism. This conclusion is based on construction and analysis of 71 karyotypes of somatic or spermatogonial cells, of which 31 are of ZZ, 29 of ZW and 11

  5. Genetic architecture of sexual dimorphism in a subdioecious plant with a proto-sex chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual dimorphism is thought to arise once sexually antagonistic genes accumulate on sex chromosomes early in their evolution. Yet because the earliest stages of sex chromosome evolution are elusive, we lack empirical evidence supporting this theory. In this study, we shed first light on the genetic...

  6. Method of detecting genetic deletions identified with chromosomal abnormalities

    DOEpatents

    Gray, Joe W; Pinkel, Daniel; Tkachuk, Douglas

    2013-11-26

    Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyzes. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acids probes are typically of a complexity greater tha 50 kb, the complexity depending upon the cytogenetic application. Methods and reagents are provided for the detection of genetic rearrangements. Probes and test kits are provided for use in detecting genetic rearrangements, particlularly for use in tumor cytogenetics, in the detection of disease related loci, specifically cancer, such as chronic myelogenous leukemia (CML) and for biological dosimetry. Methods and reagents are described for cytogenetic research, for the differentiation of cytogenetically similar ut genetically different diseases, and for many prognostic and diagnostic applications.

  7. Identification of somatic chromosomal abnormalities in hypothalamic hamartoma tissue at the GLI3 locus.

    PubMed

    Craig, David W; Itty, Abraham; Panganiban, Corrie; Szelinger, Szabolcs; Kruer, Michael C; Sekar, Aswin; Reiman, David; Narayanan, Vinodh; Stephan, Dietrich A; Kerrigan, John F

    2008-02-01

    Hypothalamic hamartomas (HH) are rare, benign congenital tumors associated with intractable epilepsy. Most cases are sporadic and nonsyndromic. Approximately 5% of HH cases are associated with Pallister-Hall syndrome (PHS), which is caused by haploinsufficiency of GLI3. We have investigated the possibility that HH pathogenesis in sporadic cases is due to a somatic (tumor-only) mutation in GLI3. We isolated genomic DNA from peripheral blood and surgically resected HH tissue in 55 patients with sporadic HH and intractable epilepsy. A genome-wide screen for loss of heterozygosity (LOH) and chromosomal abnormalities was performed with parallel analysis of blood and HH tissue with Affymetrix 10K SNP microarrays. Additionally, resequencing and fine mapping with SNP genotyping were completed for the GLI3 gene with comparisons between peripheral blood and HH tissue pairs. By analyzing chromosomal copy-number data for paired samples on the Affymetrix 10K array, we identified a somatic chromosomal abnormality on chromosome 7p in one HH tissue sample. Resequencing of GLI3 did not identify causative germline mutations but did identify LOH within the GLI3 gene in the HH tissue samples of three patients. Further genotyping of 28 SNPs within and surrounding GLI3 identified five additional patients exhibiting LOH. Together, these data provide evidence that the development of chromosomal abnormalities within GLI3 is associated with the pathogenesis of HH lesions in sporadic, nonsyndromic patients with HH and intractable epilepsy. Chromosomal abnormalities including the GLI3 locus were seen in 8 of 55 (15%) of the resected HH tissue samples. These somatic mutations appear to be highly variable. PMID:18252217

  8. Identification of Somatic Chromosomal Abnormalities in Hypothalamic Hamartoma Tissue at the GLI3 Locus

    PubMed Central

    Craig, David W.; Itty, Abraham; Panganiban, Corrie; Szelinger, Szabolcs; Kruer, Michael C.; Sekar, Aswin; Reiman, David; Narayanan, Vinodh; Stephan, Dietrich A.; Kerrigan, John F.

    2008-01-01

    Hypothalamic hamartomas (HH) are rare, benign congenital tumors associated with intractable epilepsy. Most cases are sporadic and nonsyndromic. Approximately 5% of HH cases are associated with Pallister-Hall syndrome (PHS), which is caused by haploinsufficiency of GLI3. We have investigated the possibility that HH pathogenesis in sporadic cases is due to a somatic (tumor-only) mutation in GLI3. We isolated genomic DNA from peripheral blood and surgically resected HH tissue in 55 patients with sporadic HH and intractable epilepsy. A genome-wide screen for loss of heterozygosity (LOH) and chromosomal abnormalities was performed with parallel analysis of blood and HH tissue with Affymetrix 10K SNP microarrays. Additionally, resequencing and fine mapping with SNP genotyping were completed for the GLI3 gene with comparisons between peripheral blood and HH tissue pairs. By analyzing chromosomal copy-number data for paired samples on the Affymetrix 10K array, we identified a somatic chromosomal abnormality on chromosome 7p in one HH tissue sample. Resequencing of GLI3 did not identify causative germline mutations but did identify LOH within the GLI3 gene in the HH tissue samples of three patients. Further genotyping of 28 SNPs within and surrounding GLI3 identified five additional patients exhibiting LOH. Together, these data provide evidence that the development of chromosomal abnormalities within GLI3 is associated with the pathogenesis of HH lesions in sporadic, nonsyndromic patients with HH and intractable epilepsy. Chromosomal abnormalities including the GLI3 locus were seen in 8 of 55 (15%) of the resected HH tissue samples. These somatic mutations appear to be highly variable. PMID:18252217

  9. Sperm development, age and sex chromosome meiotic drive in the stalk-eyed fly, Cyrtodiopsis whitei.

    PubMed

    Wilkinson, G S; Sanchez, M I

    2001-07-01

    The cytological basis of X chromosome meiotic drive or sex ratio (SR) has been reported for several species of Drosophila but not for other species. Here we describe how sperm development in the stalk-eyed fly, Cyrtodiopsis whitei, influences progeny sex proportion, in order to determine if a common developmental mechanism could cause meiotic drive in these distantly related taxa. Because age has been found to affect the degree of segregation distortion in some Drosophila, we tested flies from six to 26 weeks of age. We find that spermatocyst bundles in SR males frequently contain incompletely elongated spermatid nuclei independently of male age. Older males have, however, more spermatocyst bundles in their testes than younger males. Abnormal spermatid elongation affects male fertility since SR males produce 74% as many progeny per week as ST males. The proportion of spermatocyst bundles with improperly elongated spermatid nuclei explains 71% of the variation in progeny sex proportion. After reviewing the literature on sperm development and meiotic drive, we conclude that the cytological basis of meiotic drive in diopsids closely resembles Drosophila. Across species in both groups, the production of fertile males is associated with less than half of all spermatids not elongating normally in a spermatocyst bundle. We discuss the possibility that frequency-dependent selection on male fertility could stabilize the drive polymorphism in these unusual flies. PMID:11678983

  10. Multiple Sex-Associated Regions and a Putative Sex Chromosome in Zebrafish Revealed by RAD Mapping and Population Genomics

    PubMed Central

    Anderson, Jennifer L.; Rodríguez Marí, Adriana; Braasch, Ingo; Amores, Angel; Hohenlohe, Paul; Batzel, Peter; Postlethwait, John H.

    2012-01-01

    Within vertebrates, major sex determining genes can differ among taxa and even within species. In zebrafish (Danio rerio), neither heteromorphic sex chromosomes nor single sex determination genes of large effect, like Sry in mammals, have yet been identified. Furthermore, environmental factors can influence zebrafish sex determination. Although progress has been made in understanding zebrafish gonad differentiation (e.g. the influence of germ cells on gonad fate), the primary genetic basis of zebrafish sex determination remains poorly understood. To identify genetic loci associated with sex, we analyzed F2 offspring of reciprocal crosses between Oregon *AB and Nadia (NA) wild-type zebrafish stocks. Genome-wide linkage analysis, using more than 5,000 sequence-based polymorphic restriction site associated (RAD-tag) markers and population genomic analysis of more than 30,000 single nucleotide polymorphisms in our *ABxNA crosses revealed a sex-associated locus on the end of the long arm of chr-4 for both cross families, and an additional locus in the middle of chr-3 in one cross family. Additional sequencing showed that two SNPs in dmrt1 previously suggested to be functional candidates for sex determination in a cross of ABxIndia wild-type zebrafish, are not associated with sex in our AB fish. Our data show that sex determination in zebrafish is polygenic and that different genes may influence sex determination in different strains or that different genes become more important under different environmental conditions. The association of the end of chr-4 with sex is remarkable because, unique in the karyotype, this chromosome arm shares features with known sex chromosomes: it is highly heterochromatic, repetitive, late replicating, and has reduced recombination. Our results reveal that chr-4 has functional and structural properties expected of a sex chromosome. PMID:22792396

  11. Independent Origins of New Sex-Linked Chromosomes in the melanica and robusta Species Groups of Drosophila

    Microsoft Academic Search

    Sergio V Flores; Amy L Evans; Bryant F McAllister

    2008-01-01

    BACKGROUND: Recent translocations of autosomal regions to the sex chromosomes represent important systems for identifying the evolutionary forces affecting convergent patterns of sex-chromosome heteromorphism. Additions to the sex chromosomes have been reported in the melanica and robusta species groups, two sister clades of Drosophila. The close relationship between these two species groups and the similarity of their rearranged karyotypes motivates

  12. Social antics in ants inherited like sex chromosomes -life -16January 2013 -New Scientist Home Life News Back to article

    E-print Network

    Alvarez, Nadir

    as XX and XY pairs to determine sex. Keller's team discovered that two chromosome regions, social B (SBSocial antics in ants inherited like sex chromosomes - life - 16January 2013 - New Scientist Home Life News Back to article Social antics in ants inherited like sex chromosomes 18:00 16 January 2013by

  13. Step-by-step evolution of neo-sex chromosomes in geographical populations of wild silkmoths, Samia cynthia ssp

    Microsoft Academic Search

    A Yoshido; K Sahara; F Marec; Y Matsuda

    2011-01-01

    Geographical subspecies of wild silkmoths, Samia cynthia ssp. (Lepidoptera: Saturniidae), differ considerably in sex chromosome constitution owing to sex chromosome fusions with autosomes, which leads to variation in chromosome numbers. We cloned S. cynthia orthologues of 16 Bombyx mori genes and mapped them to chromosome spreads of S. cynthia subspecies by fluorescence in situ hybridization (FISH) to determine the origin

  14. Sex ratio of congenital abnormalities in the function of maternal age: A population-based study.

    PubMed

    Csermely, Gyula; Urbán, Robert; Czeizel, Andrew E; Veszprémi, Béla

    2015-05-01

    Maternal age effect is well-known in the origin of numerical chromosomal aberrations and some isolated congenital abnormalities (CAs). The sex ratio (SR), i.e. number of males divided by the number of males and females together, of most CAs deviates from the SR of newborn population (0.51). The objective of this analysis was to evaluate the possible association of maternal age with the SR of isolated CAs in a population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. First, SR of 24 CA entities/groups was estimated in 21?494 patients with isolated CA. In the next step SR of different maternal age groups was compared to the mean SR of the given CA-groups. The SR of four CA-groups showed some deviation in certain maternal age groups. Cases with anencephaly had female excess in young mothers (<25 years). Cases with skull's CAs particularly craniosynostosis had a male excess in cases born to women over 30 years. Two other CA groups (cleft lip?±?palate and valvar pulmonic stenosis within the group of right-sided obstructive defect of heart) had significant deviation in SR of certain maternal age groups from the mean SR, but these deviations were not harmonized with joining age groups and thus were considered as a chance effect due to multiple testing. In conclusion, our study did not suggest that in general SR of isolated CAs might be modified by certain maternal age groups with some exception such as anencephaly and craniosynostosis. PMID:25354028

  15. Uniparental isodisomy of chromosome 14 in two cases: An abnormal child and a normal adult

    SciTech Connect

    Papenhausen, P.R.; Mueller, O.T.; Sutcliffe, M.; Diamond, T.M.; Kousseff, B.G. [Univ. of South Florida College of Medicine, Tampa, FL (United States); Johnson, V.P. [Univ. of South Dakota, Sioux Falls, SD (United States)

    1995-11-20

    Uniparental disomy (UPD) of a number of different chromosomes has been found in association with abnormal phenotypes. A growing body of evidence for an imprinting effect involving chromosome 14 has been accumulating. We report on a case of paternal UPD of chromosome 14 studied in late gestation due to polyhydramnios and a ventral wall hernia. A prenatal karyotype documented a balanced Robertsonian 14:14 translocation. The baby was born prematurely with hairy forehead, retrognathia, mild puckering of the lips and finger contractures. Hypotonia has persisted since birth and at age one year, a tracheostomy for laryngomalacia and gastrostomy for feeding remain necessary. Absence of maternal VNTR polymorphisms and homozygosity of paternal polymorphisms using chromosome 14 specific probes at D14S22 and D14S13 loci indicated paternal uniparental isodisomy (pUPID). Parental chromosomes were normal. We also report on a case of maternal LTPD in a normal patient with a balanced Robertsonian 14:14 translocation and a history of multiple miscarriages. Five previous reports of chromosome 14 UPD suggest that an adverse developmental effect may be more severe whenever the UPD is paternal in origin. This is the second reported patient with paternal UPD and the fifth reported with maternal UPD, and only few phenotypic similarities are apparent. Examination of these chromosome 14 UPD cases of maternal and paternal origin suggests that there are syndromic imprinting effects. 30 refs., 3 figs.

  16. Molecular cytogenetics in hop (Humulus lupulus L.) and identification of sex chromosomes by DAPI-banding

    Microsoft Academic Search

    G. I. Karlov; T. V. Danilova; C. Horlemann; G. Weber

    2003-01-01

    Hop (Humulus lupulus L.) waskaryotyped by Fluorescence In SituHybridization (FISH) with probes 18S-25Sand 5S rDNA as well as DAPI banding andmeasurements of lengths of chromosome.Irrespective of the sex of the plants theseprobes revealed one signal near thetelomere of chromosome 6 and two signalseach on chromosomes 2 and 5.The shortest chromosome in a metaphaseplate of a male plant was designated to

  17. Transmission of clonal chromosomal abnormalities in human hematopoietic stem and progenitor cells surviving radiation exposure.

    PubMed

    Kraft, Daniela; Ritter, Sylvia; Durante, Marco; Seifried, Erhard; Fournier, Claudia; Tonn, Torsten

    2015-07-01

    In radiation-induced acute myeloid leukemia (rAML), clonal chromosomal abnormalities are often observed in bone marrow cells of patients, suggesting that their formation is crucial in the development of the disease. Since rAML is considered to originate from hematopoietic stem and progenitor cells (HSPC), we investigated the frequency and spectrum of radiation-induced chromosomal abnormalities in human CD34(+) cells. We then measured stable chromosomal abnormalities, a possible biomarker of leukemia risk, in clonally expanded cell populations which were grown for 14 days in a 3D-matrix (CFU-assay). We compared two radiation qualities used in radiotherapy, sparsely ionizing X-rays and densely ionizing carbon ions (29 and 60-85keV/?m, doses between 0.5 and 4Gy). Only a negligible number of de novo arising, unstable aberrations (?0.05 aberrations/cell, 97% breaks) were measured in the descendants of irradiated HSPC. However, stable aberrations were detected in colonies formed by irradiated HSPC. All cells of the affected colonies exhibited one or more identical aberrations, indicating their clonal origin. The majority of the clonal rearrangements (92%) were simple exchanges such as translocations (77%) and pericentric inversions (15%), which are known to contribute to the development of rAML. Carbon ions were more efficient in inducing cell killing (maximum of ?30-35% apoptotic cells for 2Gy carbon ions compared to ?25% for X-rays) and chromosomal aberrations in the first cell-cycle after exposure (?70% and ?40% for 1Gy of carbon ions and X-rays, respectively), with a higher fraction of non-transmissible aberrations. In contrast, for both radiation qualities the percentage of clones with chromosomal abnormalities was similar (40%). Using the frequency of colonies with clonal aberrations as a surrogate marker for the leukemia risk following radiotherapy of solid tumors, charged particle therapy is not expected to lead to an increased risk of leukemia in patients. PMID:25938904

  18. Combined Use of Cytogenetic and Molecular Methods in Prenatal Diagnostics of Chromosomal Abnormalities

    PubMed Central

    Stomornjak-Vukadin, Meliha; Kurtovic-Basic, Ilvana; Mehinovic, Lejla; Konjhodzic, Rijad

    2015-01-01

    Aim: The aim of prenatal diagnostics is to provide information of the genetic abnormalities of the fetus early enough for the termination of pregnancy to be possible. Chromosomal abnormalities can be detected in an unborn child through the use of cytogenetic, molecular- cytogenetic and molecular methods. In between them, central spot is still occupied by cytogenetic methods. In cases where use of such methods is not informative enough, one or more molecular cytogenetic methods can be used for further clarification. Combined use of the mentioned methods improves the quality of the final findings in the diagnostics of chromosomal abnormalities, with classical cytogenetic methods still occupying the central spot. Material and methods: Conducted research represent retrospective-prospective study of a four year period, from 2008 through 2011. In the period stated, 1319 karyotyping from amniotic fluid were conducted, along with 146 FISH analysis. Results: Karyotyping had detected 20 numerical and 18 structural aberrations in that period. Most common observed numerical aberration were Down syndrome (75%), Klinefelter syndrome (10%), Edwards syndrome, double Y syndrome and triploidy (5% each). Within observed structural aberrations more common were balanced chromosomal aberrations then non balanced ones. Most common balanced structural aberrations were as follows: reciprocal translocations (60%), Robertson translocations (13.3%), chromosomal inversions, duplications and balanced de novo chromosomal rearrangements (6.6% each). Conclusion: With non- balanced aberrations observed in the samples of amniotic fluid, non- balanced translocations, deletions and derived chromosomes were equally represented. Number of detected aneuploidies with FISH, prior to obtaining results with karyotyping, were 6. PMID:26005269

  19. Sex chromosome complement influences operant responding for a palatable food in mice.

    PubMed

    Seu, E; Groman, S M; Arnold, A P; Jentsch, J D

    2014-07-01

    The procurement and consumption of palatable, calorie-dense foods is influenced by the nutritional and hedonic value of foods. Although many factors can influence the control over behavior by foods rich in sugar and fat, emerging evidence indicates that biological sex may play a particularly crucial role in the types of foods individuals seek out, as well as the level of motivation individuals will exert to obtain those foods. However, a systematic investigation of food-seeking and consumption that disentangles the effects of the major sex-biasing factors, including sex chromosome complement and organizational and activational effects of sex hormones, has yet to be conducted. Using the four core genotypes mouse model system, we separated and quantified the effects of sex chromosome complement and gonadal sex on consumption of and motivation to obtain a highly palatable solution [sweetened condensed milk (SCM)]. Gonadectomized mice with an XY sex chromosome complement, compared with those with two X chromosomes, independent of gonadal sex, appeared to be more sensitive to the reward value of the SCM solution and were more motivated to expend effort to obtain it, as evidenced by their dramatically greater expended effort in an instrumental task with progressively larger response-to-reward ratios. Gonadal sex independently affected free consumption of the solution but not motivation to obtain it. These data indicate that gonadal and chromosomal sex effects independently influence reward-related behaviors, contributing to sexually dimorphic patterns of behavior related to the pursuit and consumption of rewards. PMID:24861924

  20. Identification of a novel retrotransposon with sex chromosome-specific distribution in Silene latifolia.

    PubMed

    Kralova, Tereza; Cegan, Radim; Kubat, Zdenek; Vrana, Jan; Vyskot, Boris; Vogel, Ivan; Kejnovsky, Eduard; Hobza, Roman

    2014-01-01

    Silene latifolia is a dioecious plant species with chromosomal sex determination. Although the evolution of sex chromosomes in S. latifolia has been the subject of numerous studies, a global view of X chromosome structure in this species is still missing. Here, we combine X chromosome microdissection and BAC library screening to isolate new X chromosome-linked sequences. Out of 8 identified BAC clones, only BAC 86M14 showed an X-preferential signal after FISH experiments. Further analysis revealed the existence of the Athila retroelement which is enriched in the X chromosome and nearly absent in the Y chromosome. Based on previous data, the Athila retroelement belongs to the CL3 group of most repetitive sequences in the S. latifolia genome. Structural, transcriptomics and phylogenetic analyses revealed that Athila CL3 represents an old clade in the Athila lineage. We propose a mechanism responsible for Athila CL3 distribution in the S. latifolia genome. PMID:24751661

  1. C-banded karyotypes of two Silene species with heteromorphic sex chromosomes.

    PubMed

    Grabowska-Joachimiak, Aleksandra; Joachimiak, Andrzej

    2002-04-01

    Mitotic metaphase chromosomes of Silene latifolia (white campion) and Silene dioica (red campion) were studied and no substantial differences between the conventional karyotypes of these two species were detected. The classification of chromosomes into three distinct groups proposed for S. latifolia by Ciupercescu and colleagues was considered and discussed. Additionally, a new small satellite on the shorter arm of homobrachial chromosome 5 was found. Giemsa C-banded chromosomes of the two analysed species show many fixed and polymorphic heterochromatic bands, mainly distally and centromerically located. Our C-banding studies provided an opportunity to better characterize the sex chromosomes and some autosome types, and to detect differences between the two Silene karyotypes. It was shown that S. latifolia possesses a larger amount of polymorphic heterochromatin, especially of the centromeric type. The two Silene sex chromosomes are easily distinguishable not only by length or DNA amount differences but also by their Giemsa C-banding patterns. All Y chromosomes invariably show only one distally located band, and no other fixed or polymorphic bands on this chromosome were observed in either species. The X chromosomes possess two terminally located fixed bands, and some S. latifolia X chromosomes also have an extra-centric segment of variable length. The heterochromatin amount and distribution revealed by our Giemsa C-banding studies provide a clue to the problem of sex chromosome and karyotype evolution in these two closely related dioecious Silene species. PMID:11962621

  2. Nuchal translucency and other first-trimester sonographic markers of chromosomal abnormalities

    Microsoft Academic Search

    Kypros H. Nicolaides

    2004-01-01

    There is extensive evidence that effective screening for major chromosomal abnormalities can be provided in the first trimester of pregnancy. Prospective studies in a total of 200,868 pregnancies, including 871 fetuses with trisomy 21, have demonstrated that increased nuchal translucency can identify 76.8% of fetuses with trisomy 21, which represents a false-positive rate of 4.2%. When fetal nuchal translucency was

  3. Sex chromosome system ZZ/ZW in Apareiodon hasemani Eigenmann, 1916 (Characiformes, Parodontidae) and a derived chromosomal region.

    PubMed

    Bellafronte, Elisangela; Schemberger, Michelle Orane; Artoni, Roberto Ferreira; Filho, Orlando Moreira; Vicari, Marcelo Ricardo

    2012-12-01

    Parodontidae fish show few morphological characteristics for the identification of their representatives and chromosomal analyses have provided reliable features for determining the interrelationships in this family. In this study, the chromosomes of Apareiodon hasemani from the Săo Francisco River basin, Brazil, were analyzed and showed a karyotype with 2n = 54 meta/submetacentric chromosomes, and a ZZ/ZW sex chromosome system. The study revealed active NORs located on pair 11 and additional 18S rDNA sites on pairs 7 and 22. The 5S rDNA locus was found in pair 14. It showed a pericentric inversion regarding the ancestral condition. The satellite DNA pPh2004 was absent in the chromosomes of A. hasemani, a shared condition with most members of Apareiodon. The WAp probe was able to detect the amplification region of the W chromosome, corroborating the common origin of the system within Parodontidae. These chromosomal data corroborate an origin for the ZW system of Parodontidae and aid in the understanding of the differentiation of sex chromosome systems in Neotropical fishes. PMID:23271937

  4. Sex chromosome system ZZ/ZW in Apareiodon hasemani Eigenmann, 1916 (Characiformes, Parodontidae) and a derived chromosomal region

    PubMed Central

    Bellafronte, Elisangela; Schemberger, Michelle Orane; Artoni, Roberto Ferreira; Filho, Orlando Moreira; Vicari, Marcelo Ricardo

    2012-01-01

    Parodontidae fish show few morphological characteristics for the identification of their representatives and chromosomal analyses have provided reliable features for determining the interrelationships in this family. In this study, the chromosomes of Apareiodon hasemani from the Săo Francisco River basin, Brazil, were analyzed and showed a karyotype with 2n = 54 meta/submetacentric chromosomes, and a ZZ/ZW sex chromosome system. The study revealed active NORs located on pair 11 and additional 18S rDNA sites on pairs 7 and 22. The 5S rDNA locus was found in pair 14. It showed a pericentric inversion regarding the ancestral condition. The satellite DNA pPh2004 was absent in the chromosomes of A. hasemani, a shared condition with most members of Apareiodon. The WAp probe was able to detect the amplification region of the W chromosome, corroborating the common origin of the system within Parodontidae. These chromosomal data corroborate an origin for the ZW system of Parodontidae and aid in the understanding of the differentiation of sex chromosome systems in Neotropical fishes. PMID:23271937

  5. Physical chromosome mapping of repetitive DNA sequences in Nile tilapia Oreochromis niloticus: Evidences for a differential distribution of repetitive elements in the sex chromosomes

    Microsoft Academic Search

    Irani A. Ferreira; Cesar Martins

    2008-01-01

    Repetitive DNAs have been extensively applied as physical chromosome markers on comparative studies, identification of chromosome rearrangements and sex chromosomes, chromosome evolution analysis, and applied genetics. Here we report the characterization of repetitive DNA sequences from the Nile tilapia (Oreochromis niloticus) genome by construction and screening of plasmid library enriched with repetitive DNAs, analysis of a BAC-based physical map, and

  6. Effects of sex chromosome aneuploidies on brain development: evidence from neuroimaging studies.

    PubMed

    Lenroot, Rhoshel K; Lee, Nancy Raitano; Giedd, Jay N

    2009-01-01

    Variation in the number of sex chromosomes is a relatively common genetic condition, affecting as many as 1/400 individuals. The sex chromosome aneuploidies (SCAs) are associated with characteristic behavioral and cognitive phenotypes, although the degree to which specific individuals are affected can fall within a wide range. Understanding the effects of different dosages of sex chromosome genes on brain development may help to understand the basis for functional differences in affected individuals. It may also be informative regarding how sex chromosomes contribute to typical sexual differentiation. Studies of 47,XXY males make up the bulk of the current literature of neuroimaging studies in individuals with supernumerary sex chromosomes, with a few small studies or case reports of the other SCAs. Findings in 47,XXY males typically include decreased gray and white matter volumes, with most pronounced effects in the frontal and temporal lobes. Functional studies have shown evidence of decreased lateralization. Although the hypogonadism typically found in 47,XXY males may contribute to the decreased brain volume, the observation that 47,XXX females also show decreased brain volume in the presence of normal pubertal maturation suggests a possible direct dosage effect of X chromosome genes. Additional X chromosomes, such as in 49,XXXXY males, are associated with more markedly decreased brain volume and increased incidence of white matter hyperintensities. The limited data regarding effects of having two Y chromosomes (47,XYY) do not find significant differences in brain volume, although there are some reports of increased head size. PMID:20014372

  7. Identification of sex chromosome molecular markers using RAPDs and fluorescent in situ hybridization in rainbow trout

    Microsoft Academic Search

    P. Iturra; J. F. Medrano; M. Bagley; N. Lam; N. Vergara; J. C. Marin

    1997-01-01

    The goal of this work is to identify molecular markers associated with the sex chromosomes in rainbow trout to study the mode\\u000a of sex determination mechanisms in this species. Using the RAPD assay and bulked segregant analysis, two markers were identified\\u000a that generated polymorphic bands amplifying preferentially in males of the Mount Lassen and Scottish strains of rainbow trout.\\u000a Chromosomal

  8. Volumetric magnetic resonance imaging study of the brain in subjects with sex chromosome aneuploidies

    Microsoft Academic Search

    Michael M Warwick; Gillian A Doody; Stephen M Lawrie; Julia N Kestelman; Jonathan J K Best; Eve C Johnstone

    1999-01-01

    OBJECTIVESCognitive impairment has been reported in people with sex chromosome aneuploides (SCAs) and it has been proposed that the presence of an extra sex chromosome may have an adverse effect on neurodevelopment. This study examines the hypothesis with structural MRI of the brain.METHODSThirty two subjects with SCA (XXX (n=12), XYY (n=10), and XXY (n=10)) from a birth cohort study were

  9. Accumulation of Y-specific satellite DNAs during the evolution of Rumex acetosa sex chromosomes

    Microsoft Academic Search

    Beatrice Mariotti; Susana Manzano; Eduard Kejnovský; Boris Vyskot; Manuel Jamilena

    2009-01-01

    The study of the molecular structure of young heteromorphic sex chromosomes of plants has shed light on the evolutionary forces\\u000a that control the differentiation of the X and Y during the earlier stages of their evolution. We have used the model plant\\u000a Rumex acetosa, a dioecious species with multiple sex chromosomes, 2n = 12 + XX female and 2n = 12 + XY1Y2 male, to analyse the significance

  10. Molecular detection of chromosomal abnormalities in germ and somatic cells of aged male mice

    SciTech Connect

    Lowe, X.; Baulch, J.; Quintana, L.; Ramsey, M.; Breneman, J.; Tucker, J.; Wyrobek, A. [Lawrence Livermore National Laboratory, CA (United States); Collins, B.; Allen, J. [EPA, Research Triangle Park, NC (United States); Holland, N. [Univ. of California, Berkeley, CA (United States)

    1994-12-31

    Three cytogenetic methods were applied to eight B6C3F1 male mice aged 22.5 - 30.5mo to determine if advanced age was associated with an elevated risk of producing chromosomally defective germinal and somatic cells; sperm aneuploidy analysis by multi-color fluorescence in situ hybridization for three chromosomes, spermatid micronucleus analysis with anti-kinetochore antibodies, and translocation analysis of somatic metaphases by {open_quotes}painting{close_quotes} for two chromosomes. Eight mice aged 2.4mo served as controls. Sperm aneuploidy was measured by multi-color fluorescence in situ co-hybridization with DNA probes specific for chromosomes X, Y and 8, scoring 10,000 cells per animal. The aged group showed significant 1.5 - 2.0 fold increases in the hyperhaploidy phenotypes X-X-8, Y-Y-8, 8-8-Y, and 8-8-X with the greater effects appearing in animals aged >29mo. The aged group also showed significantly increased frequencies of micronucleated spermatids (2.0 vs 0.4 per 1000; all were kinetochore negative). Analysis of metaphase chromosomes from blood by {open_quotes}painting{close_quotes} of chromosomes 2 and 8 yielded 4 translocation per 858 cell-equivalents in the aged group which was a non-significant elevation over 0/202 in controls. Although interpretation must be cautious due to the small number of animals analyzed, these findings suggest that advanced paternal age may be a risk factor for chromosomal abnormalities of reproductive and somatic importance.

  11. Transition in sexual system and sex chromosome evolution in the tadpole shrimp Triops cancriformis.

    PubMed

    Mathers, T C; Hammond, R L; Jenner, R A; Hänfling, B; Atkins, J; Gómez, A

    2015-07-01

    Transitions in sexual system and reproductive mode may affect the course of sex chromosome evolution, for instance by altering the strength of sexually antagonistic selection. However, there have been few studies of sex chromosomes in systems where such transitions have been documented. The European tadpole shrimp, Triops cancriformis, has undergone a transition from dioecy to androdioecy (a sexual system where hermaphrodites and males coexist), offering an excellent opportunity to test the impact of this transition on the evolution of sex chromosomes. To identify sex-linked markers, to understand mechanisms of sex determination and to investigate differences between sexual systems, we carried out a genome-wide association study using restriction site-associated DNA sequencing (RAD-seq) of 47 males, females and hermaphrodites from one dioecious and one androdioecious population. We analysed 22.9?Gb of paired-end sequences and identified and scored >3000 high coverage novel genomic RAD markers. Presence-absence of markers, single-nucleotide polymorphism association and read depth identified 52 candidate sex-linked markers. We show that sex is genetically determined in T. cancriformis, with a ZW system conserved across dioecious and androdioecious populations and that hermaphrodites have likely evolved from females. We also show that the structure of the sex chromosomes differs strikingly, with a larger sex-linked region in the dioecious population compared with the androdioecious population. PMID:25757406

  12. Independent origin of sex chromosomes in two species of the genus Silene.

    PubMed

    Mrackova, Martina; Nicolas, Michael; Hobza, Roman; Negrutiu, Ioan; Monéger, Françoise; Widmer, Alexander; Vyskot, Boris; Janousek, Bohuslav

    2008-06-01

    Here we introduce a new model species, Silene colpophylla, that could facilitate research of sex chromosome evolution and sex-determining systems. This species is related to the well-established dioecious plant model Silene latifolia. Our results show that S. colpophylla is, similarly to S. latifolia, a male heterogametic species, but its sex chromosomes have evolved from a different pair of autosomes than in S. latifolia. The results of our phylogenetic study and mapping of homologs of S. latifolia X-linked genes indicate that the sex determination system in S. colpophylla evolved independently from that in S. latifolia. We assert that this model species pair will make it possible to study two independent patterns of sex chromosome evolution in related species. PMID:18558658

  13. Plant genetics. A Y-chromosome-encoded small RNA acts as a sex determinant in persimmons.

    PubMed

    Akagi, Takashi; Henry, Isabelle M; Tao, Ryutaro; Comai, Luca

    2014-10-31

    In plants, multiple lineages have evolved sex chromosomes independently, providing a powerful comparative framework, but few specific determinants controlling the expression of a specific sex have been identified. We investigated sex determinants in the Caucasian persimmon, Diospyros lotus, a dioecious plant with heterogametic males (XY). Male-specific short nucleotide sequences were used to define a male-determining region. A combination of transcriptomics and evolutionary approaches detected a Y-specific sex-determinant candidate, OGI, that displays male-specific conservation among Diospyros species. OGI encodes a small RNA targeting the autosomal MeGI gene, a homeodomain transcription factor regulating anther fertility in a dosage-dependent fashion. This identification of a feminizing gene suppressed by a Y-chromosome-encoded small RNA contributes to our understanding of the evolution of sex chromosome systems in higher plants. PMID:25359977

  14. A Model System for Study of Sex Chromosome Effects on Sexually Dimorphic Neural and Behavioral Traits

    Microsoft Academic Search

    Geert J. De Vries; Emilie F. Rissman; Richard B. Simerly; Liang-Yo Yang; Elka M. Scordalakes; Catherine J. Auger; Amanda Swain; Robin Lovell-Badge; Paul S. Burgoyne; Arthur P. Arnold

    2002-01-01

    We tested the hypothesis that genes encoded on the sex chromosomes play a direct role in sexual differentiation of brain and behavior. We used mice in which the testis-determining gene (Sry) was moved from the Y chromosome to an autosome (by deletion of Sry from the Y and subsequent insertion of an Sry transgene onto an autosome), so that the

  15. Expression pattern of X-linked genes in sex chromosome aneuploid bovine cells

    Microsoft Academic Search

    Parvathi K. Basrur; Ali Farazmand; Gerald Stranzinger; Daria Graphodatskaya; Ed R. Reyes; W. Allan King

    2004-01-01

    Expression of the X-inactive specific transcript (XIST) gene is a prerequisite step for dosage compensation in mammals, accomplished by silencing one of the two X chromosomes in\\u000a normal female diploid cells or all X chromosomes in excess of one in sex chromosome aneuploids. Our previous studies showing\\u000a that XIST expression does not eventuate the inactivation of X-linked genes in fetal

  16. Prenatal diagnosis of chromosome 15 abnormalities in the Prader-Willi/Angelman syndrome region by traditional and molecular cytogenetics

    SciTech Connect

    Toth-Fejel, S.; Magenis, R.E.; Leff, S. [Oregon Health Sciences Univ., Portland, OR (United States)] [and others

    1995-02-13

    With improvements in culturing and banding techniques, amniotic fluid studies now achieve a level of resolution at which the Prader-Willi syndrome (PWS) and Angelman syndrome (AS) region may be questioned. Chromosome 15 heteromorphisms, detected with Q- and R-banding and used in conjunction with PWS/AS region-specific probes, can confirm a chromosome deletion and establish origin to predict the clinical outcome. We report four de novo cases of an abnormal-appearing chromosome 15 in amniotic fluid samples referred for advanced maternal age or a history of a previous chromosomally abnormal child. The chromosomes were characterized using G-, Q-, and R-banding, as well as isotopic and fluorescent in situ hybridization of DNA probes specific for the proximal chromosome 15 long arm. In two cases, one chromosome 15 homolog showed a consistent deletion of the ONCOR PWS/AS region A and B. In the other two cases, one of which involved an inversion with one breakpoint in the PWS/AS region, all of the proximal chromosome 15 long arm DNA probes used in the in situ hybridization were present on both homologs. Clinical follow-up was not available on these samples, as in all cases the parents chose to terminate the pregnancies. These cases demonstrate the ability to prenatally diagnose chromosome 15 abnormalities associated with PWS/AS. In addition, they highlight the need for a better understanding of this region for accurate prenatal diagnosis. 41 refs., 5 figs.

  17. Independent Evolution of Transcriptional Inactivation on Sex Chromosomes in Birds and Mammals

    PubMed Central

    Livernois, Alexandra M.; Waters, Shafagh A.; Deakin, Janine E.; Marshall Graves, Jennifer A.; Waters, Paul D.

    2013-01-01

    X chromosome inactivation in eutherian mammals has been thought to be tightly controlled, as expected from a mechanism that compensates for the different dosage of X-borne genes in XX females and XY males. However, many X genes escape inactivation in humans, inactivation of the X in marsupials is partial, and the unrelated sex chromosomes of monotreme mammals have incomplete and gene-specific inactivation of X-linked genes. The bird ZW sex chromosome system represents a third independently evolved amniote sex chromosome system with dosage compensation, albeit partial and gene-specific, via an unknown mechanism (i.e. upregulation of the single Z in females, down regulation of one or both Zs in males, or a combination). We used RNA-fluorescent in situ hybridization (RNA-FISH) to demonstrate, on individual fibroblast cells, inactivation of 11 genes on the chicken Z and 28 genes on the X chromosomes of platypus. Each gene displayed a reproducible frequency of 1Z/1X-active and 2Z/2X-active cells in the homogametic sex. Our results indicate that the probability of inactivation is controlled on a gene-by-gene basis (or small domains) on the chicken Z and platypus X chromosomes. This regulatory mechanism must have been exapted independently to the non-homologous sex chromosomes in birds and mammals in response to an over-expressed Z or X in the homogametic sex, highlighting the universal importance that (at least partial) silencing plays in the evolution on amniote dosage compensation and, therefore, the differentiation of sex chromosomes. PMID:23874231

  18. Chromosomal abnormalities resembling Joubert syndrome: two cases illustrating the diagnostic pitfalls.

    PubMed

    Kroes, Hester Y; Hochstenbach, Ron; Nievelstein, Rutger A J; Den Hollander, Anneke I; Lugtenberg, Dorien T; Van Nieuwenhuizen, Onno; Lindhout, Dick; Poot, Martin

    2011-07-01

    We describe two patients with severe developmental delay, hypotonia and breathing abnormalities initially diagnosed with the autosomal recessive Joubert syndrome (JBS) who at a later stage appeared to carry chromosomal abnormalities. One case was due to a 4.8 Mb terminal 1q44 deletion, and the other due to a 15.5 Mb duplication of Xq27.2-qter containing the MECP2 gene. Critical evaluation of the clinical data showed that, retrospectively, the cases did not fulfil the diagnostic criteria for JBS, and that the diagnosis of JBS was incorrectly made. We discuss the diagnostic pitfalls and recommend adhering strictly to the JBS diagnostic criteria in the case of a negative molecular diagnosis. Critical assessment of the MRI findings by a specialized neuroradiologist is imperative. As chromosomal abnormalities may give rise to symptoms resembling JBS, we recommend array-based screening for segmental aneuploidies as an initial genetic test in all cases with a JBS-like phenotype. PMID:21527849

  19. Evolutionary Strata on the X Chromosomes of the Dioecious Plant Silene latifolia: Evidence From New Sex-Linked Genes

    Microsoft Academic Search

    Roberta Bergero; Alan Forrest; Esther Kamau; Deborah Charlesworth

    2007-01-01

    Despite its recent evolutionary origin, the sex chromosome system of the plant Silene latifolia shows signs of progressive suppression of recombination having created evolutionary strata of different X-Y divergence on sex chromosomes. However, even after 8 years of effort, this result is based on analyses of five sex-linked gene sequences, and the maximum divergence (and thus the age of this

  20. CpG island methylator phenotype associates with low-degree chromosomal abnormalities in colorectal cancer

    PubMed Central

    Cheng, Yu-Wei; Pincas, Hanna; Bacolod, Manny; Schemmann, Gunter; Giardina, Sarah F.; Huang, Jianmin; Barral, Sandra; Idrees, Kamran; Khan, Sajid A.; Zeng, Zhaoshi; Rosenberg, Shoshana; Notterman, Daniel A.; Ott, Jurg; Paty, Philip; Barany, Francis

    2012-01-01

    Purpose Aberrant promoter methylation and genomic instability occur frequently during colorectal cancer (CRC) development. CpG island methylator phenotype (CIMP) has been shown to associate with microsatellite instability, BRAF mutation and often found in the right-side colon. Nevertheless, the relative importance of CIMP and chromosomal instability (CIN) for tumorigenesis has yet to be thoroughly investigated in sporadic CRCs. Experimental Design We determined CIMP in 161 primary CRCs and 66 matched normal mucosae using a quantitative bisulfite/PCR/LDR/Universal Array assay. The validity of CIMP was confirmed in a subset of 60 primary tumors using MethyLight assay and five independent markers. In parallel, chromosomal instability was analyzed in the same study cohort using Affymetrix 50K Human Mapping arrays. Results The identified CIMP-positive cancers correlate with microsatellite instability (p=0.075) and the BRAF mutation V600E (p=0.00005). The array-based high-resolution analysis of chromosomal aberrations indicated that the degree of aneuploidy is spread over a wide spectrum among analyzed CRCs. Whether CIN was defined by copy number variations in selected microsatellite loci (criterion 1) or considered as a continuous variable (criterion 2), CIMP-positive samples showed a strong correlation with low-degree chromosomal aberrations (p=0.075 and 0.012, respectively). Similar correlations were observed when CIMP was determined using MethyLight assay (p=0.001 and 0.013, respectively). Conclusion CIMP-positive tumors generally possess lower chromosomal aberrations, which may only be revealed using a genome-wide approach. The significant difference in the degree of chromosomal aberrations between CIMP-positive and the remainder samples suggests that epigenetic (CIMP) and genetic (CIN) abnormalities may arise from independent molecular mechanisms of tumor progression. PMID:18829479

  1. Association testing to detect gene–gene interactions on sex chromosomes in trio data

    PubMed Central

    Lee, Yeonok; Ghosh, Debashis; Zhang, Yu

    2013-01-01

    Autism Spectrum Disorder (ASD) occurs more often among males than females in a 4:1 ratio. Among theories used to explain the causes of ASD, the X chromosome and the Y chromosome theories attribute ASD to the X-linked mutation and the male-limited gene expressions on the Y chromosome, respectively. Despite the rationale of the theory, studies have failed to attribute the sex-biased ratio to the significant linkage or association on the regions of interest on X chromosome. We further study the gender biased ratio by examining the possible interaction effects between two genes in the sex chromosomes. We propose a logistic regression model with mixed effects to detect gene–gene interactions on sex chromosomes. We investigated the power and type I error rates of the approach for a range of minor allele frequencies and varying linkage disequilibrium between markers and QTLs. We also evaluated the robustness of the model to population stratification. We applied the model to a trio-family data set with an ASD affected male child to study gene–gene interactions on sex chromosomes. PMID:24312118

  2. Molecular Cytogenetic Characterization of the Dioecious Cannabis sativa with an XY Chromosome Sex Determination System

    PubMed Central

    Divashuk, Mikhail G.; Alexandrov, Oleg S.; Razumova, Olga V.; Kirov, Ilya V.; Karlov, Gennady I.

    2014-01-01

    Hemp (Cannabis sativa L.) was karyotyped using by DAPI/C-banding staining to provide chromosome measurements, and by fluorescence in situ hybridization with probes for 45 rDNA (pTa71), 5S rDNA (pCT4.2), a subtelomeric repeat (CS-1) and the Arabidopsis telomere probes. The karyotype has 18 autosomes plus a sex chromosome pair (XX in female and XY in male plants). The autosomes are difficult to distinguish morphologically, but three pairs could be distinguished using the probes. The Y chromosome is larger than the autosomes, and carries a fully heterochromatic DAPI positive arm and CS-1 repeats only on the less intensely DAPI-stained, euchromatic arm. The X is the largest chromosome of all, and carries CS-1 subtelomeric repeats on both arms. The meiotic configuration of the sex bivalent locates a pseudoautosomal region of the Y chromosome at the end of the euchromatic CS-1-carrying arm. Our molecular cytogenetic study of the C. sativa sex chromosomes is a starting point for helping to make C. sativa a promising model to study sex chromosome evolution. PMID:24465491

  3. Molecular cytogenetic characterization of the dioecious Cannabis sativa with an XY chromosome sex determination system.

    PubMed

    Divashuk, Mikhail G; Alexandrov, Oleg S; Razumova, Olga V; Kirov, Ilya V; Karlov, Gennady I

    2014-01-01

    Hemp (Cannabis sativa L.) was karyotyped using by DAPI/C-banding staining to provide chromosome measurements, and by fluorescence in situ hybridization with probes for 45 rDNA (pTa71), 5S rDNA (pCT4.2), a subtelomeric repeat (CS-1) and the Arabidopsis telomere probes. The karyotype has 18 autosomes plus a sex chromosome pair (XX in female and XY in male plants). The autosomes are difficult to distinguish morphologically, but three pairs could be distinguished using the probes. The Y chromosome is larger than the autosomes, and carries a fully heterochromatic DAPI positive arm and CS-1 repeats only on the less intensely DAPI-stained, euchromatic arm. The X is the largest chromosome of all, and carries CS-1 subtelomeric repeats on both arms. The meiotic configuration of the sex bivalent locates a pseudoautosomal region of the Y chromosome at the end of the euchromatic CS-1-carrying arm. Our molecular cytogenetic study of the C. sativa sex chromosomes is a starting point for helping to make C. sativa a promising model to study sex chromosome evolution. PMID:24465491

  4. A sex-linked enzyme in birds-Z-chromosome conservation but no dosage compensation

    Microsoft Academic Search

    P. R. Baverstock; M. Adams; R. W. Polkinghorne; M. Gelder

    1982-01-01

    In birds, the female is the heterogametic sex and the sex-determining system is referred to as ZZ\\/ZW. In mammals the male is heterogametic, and the sex-determining system is referred to as XX\\/XY. The mammalian X chromosome appears to have been conserved largely intact during evolution. Thus the structural gene loci for glucose-6-phosphate de-hydrogenase, phosphoglycerate kinase, alpha-galactosidase and hypoxanthine-guanine phosphoribosyltransferase are

  5. A sex-chromosome mutation in Silene latifolia

    Microsoft Academic Search

    Paige M. MillerRichard; Richard V. Kesseli

    Silene latifolia is dioecious, yet rare hermaphrodites have been found, and such natural mutants can provide valuable insight into genetic\\u000a mechanisms. Here, we describe a hermaphrodite-inducing mutation that is almost certainly localized to the gynoecium-suppression\\u000a region of the Y chromosome in S. latifolia. The mutant Y chromosome was passed through the megaspore, and the presence of two X chromosomes was

  6. Mapping of Sex Determination Loci on the White Campion (Silene latifolia )Y Chromosome Using Amplified Fragment Length Polymorphism

    Microsoft Academic Search

    Sabine Lebel-Hardenack; Elizabeth Hauser; Teresa F. Law; Jurg Schmid; Sarah R. Grant

    2002-01-01

    S. latifolia is a dioecious plant with morphologically distinct sex chromosomes. To genetically map the sex determination loci on the male-specific Y chromosome, we identified X-ray-induced sex determination mutants that had lost male traits. We used male-specific AFLP markers to characterize the extent of deletions in the Y chromosomes of the mutants. We then compared overlapping deletions to predict the

  7. Flow sorting of the Y sex chromosome in the dioecious plant Melandrium album

    SciTech Connect

    Veuskens, J.; Jacobs, M.; Negrutiu, I. [Free Univ. of Brussels (Belgium)] [and others

    1995-12-01

    The preparation of stable chromosome suspensions and flow cytometric sorting of both the Y sex chromosome of the white campion, Melandrium album, and the deleted Y chromosome of an asexual mutant, 5K63, is described. The principle has been to maintain transformed roots in vitro, synchronize and block mitosis, reduce cells to protoplasts, and lyse these to release chromosomes. Such in vitro material, unlike many cell suspensions, showed a stable karyotype. Factors critical to producing high-quality chromosome suspensions from protoplasts include osmolality of isolation solutions and choice of spindle toxin and of lysis buffer. Agrobacterium rhizogenes transformed young growing root cultures were synchronized at G1/S with 50 {mu}M aphidicolin for 24 h and released to a mitotic block with 30 {mu}M oryzalin for 11 h. Protoplast preparations from such tissue routinely had metaphase indices reaching 15%. Suspensions of intact metaphase chromosomes, with few chromatids, were obtained by lysing swollen mitotic protoplasts in a citric acid/disodium phosphate buffer. Except for the presence of clumps of autosomal chromosomes near the X and Y chromosome zones, monoparametric histograms of fluorescence intensities of suspensions stained with 4{prime},6-diamidino-2-phenylindole showed profiles similar to theoretical flow karyotypes. Two types of Y chromosomes, one full-length and one partially deleted (from the asexual mutant), could be sorted at 90% purity (21-fold enrichment of Y). These results are discussed in the context of sex determination and differentiation in higher plants. 45 refs., 6 figs., 2 tabs.

  8. Dgcr8 and Dicer are essential for sex chromosome integrity during meiosis in males.

    PubMed

    Modzelewski, Andrew J; Hilz, Stephanie; Crate, Elizabeth A; Schweidenback, Caterina T H; Fogarty, Elizabeth A; Grenier, Jennifer K; Freire, Raimundo; Cohen, Paula E; Grimson, Andrew

    2015-06-15

    Small RNAs play crucial roles in regulating gene expression during mammalian meiosis. To investigate the function of microRNAs (miRNAs) and small interfering RNAs (siRNAs) during meiosis in males, we generated germ-cell-specific conditional deletions of Dgcr8 and Dicer in mice. Analysis of spermatocytes from both conditional knockout lines revealed that there were frequent chromosomal fusions during meiosis, always involving one or both sex chromosomes. RNA sequencing indicates upregulation of Atm in spermatocytes from miRNA-deficient mice, and immunofluorescence imaging demonstrates an increased abundance of activated ATM kinase and mislocalization of phosphorylated MDC1, an ATM phosphorylation substrate. The Atm 3'UTR contains many potential microRNA target sites, and, notably, target sites for several miRNAs depleted in both conditional knockout mice were highly effective at promoting repression. RNF8, a telomere-associated protein whose localization is controlled by the MDC1-ATM kinase cascade, normally associates with the sex chromosomes during pachytene, but in both conditional knockouts redistributed to the autosomes. Taken together, these results suggest that Atm dysregulation in microRNA-deficient germ lines contributes to the redistribution of proteins involved in chromosomal stability from the sex chromosomes to the autosomes, resulting in sex chromosome fusions during meiotic prophase I. PMID:25934699

  9. Dgcr8 and Dicer are essential for sex chromosome integrity during meiosis in males

    PubMed Central

    Modzelewski, Andrew J.; Hilz, Stephanie; Crate, Elizabeth A.; Schweidenback, Caterina T. H.; Fogarty, Elizabeth A.; Grenier, Jennifer K.; Freire, Raimundo; Cohen, Paula E.; Grimson, Andrew

    2015-01-01

    ABSTRACT Small RNAs play crucial roles in regulating gene expression during mammalian meiosis. To investigate the function of microRNAs (miRNAs) and small interfering RNAs (siRNAs) during meiosis in males, we generated germ-cell-specific conditional deletions of Dgcr8 and Dicer in mice. Analysis of spermatocytes from both conditional knockout lines revealed that there were frequent chromosomal fusions during meiosis, always involving one or both sex chromosomes. RNA sequencing indicates upregulation of Atm in spermatocytes from miRNA-deficient mice, and immunofluorescence imaging demonstrates an increased abundance of activated ATM kinase and mislocalization of phosphorylated MDC1, an ATM phosphorylation substrate. The Atm 3?UTR contains many potential microRNA target sites, and, notably, target sites for several miRNAs depleted in both conditional knockout mice were highly effective at promoting repression. RNF8, a telomere-associated protein whose localization is controlled by the MDC1–ATM kinase cascade, normally associates with the sex chromosomes during pachytene, but in both conditional knockouts redistributed to the autosomes. Taken together, these results suggest that Atm dysregulation in microRNA-deficient germ lines contributes to the redistribution of proteins involved in chromosomal stability from the sex chromosomes to the autosomes, resulting in sex chromosome fusions during meiotic prophase I. PMID:25934699

  10. DNA replication in the sex chromosomes of the pronghorn and the Rocky Mountain goat.

    PubMed

    Dain, A

    1977-01-01

    The X chromosomes of the male pronghorn (Antilocapra americana) is larger than the "original" type and carries a large segment of late-labelling chromatin. The Y chromosome has a late-labelling segment that appears to duplicate synchronously with that of the X. Both chromosomes have segments that label throughout the period of observation; that the X is about 4.7% of the haploid complement and approaches "original" proportions. The X chromosomes of the Rocky Mountain goat (Oreamnos americanus) appear to be of the "original" type, without marked late-labelling regions, and the Y chromosomes is small. The structure and origin of extra-large sex chromosomes are discussed. PMID:862436

  11. Comparison of Abnormal Cervical Cytology from HIV Positive Women, Female Sex Workers and General Population

    PubMed Central

    Vafaei, Homeira; Asadi, Nasrin; Foroughinia, Leila; Salehi, Alireza; Kuhnavard, Safieh; Akbarzadeh, Mojgan; Ravanbod, Hamid Reza; Mohamadalian, Ferdos; Kasraeian, Maryam

    2015-01-01

    Background Sex workers and HIV seropositive women are at high risk of abnormal cervical cytology. The objective of this study was to compare the cervical cytology among three groups of women: active sex workers, HIV-infected women, and general population in Iran. Methods This was a cross-sectional study performed in Hazrat Zeinab, Lavan clinics and drop in center (DIC) in Shiraz, Iran. This study was performed from October 2009 to October 2011. A total of 266 patients were assigned into three groups: sex-workers (85), HIV positive patients (100), and general population (81). Pap smear was performed for all participants from the exocervix and endocervix, using a plastic Ayres’s spatula and cytobrush. The samples were sent to a pathology center, using a liquid-based media.  Results The risk of cervical infection in sex workers and HIV positive women was greater than the general population (OR=5.47, 95% confidence interval [CI]:2.24, 13.40), (OR=3.71, 95% CI:1.52, 9.09), respectively. The frequency of abnormal cervical cytology in the HIV positive and sex worker groups was higher than the general population (OR=6. 76, 95% CI:2.25, 20.32), (OR=3. 80, 95% CI:1.19, 12.07), respectively. Low-grade squamous intraepithelial lesion (LSIL) and high-grade squamous intraepithelial lesion (HSIL) were associated with CD4 cell count<200Í106/L, P=0.021 and P<0.001, respectively. Conclusion Vaginal infections were seen more often in the sex worker group, and abnormal cervical cytology was greater in the HIV positive group. PMID:26005687

  12. Ancestral Chromatin Configuration Constrains Chromatin Evolution on Differentiating Sex Chromosomes in Drosophila

    PubMed Central

    Zhou, Qi; Bachtrog, Doris

    2015-01-01

    Sex chromosomes evolve distinctive types of chromatin from a pair of ancestral autosomes that are usually euchromatic. In Drosophila, the dosage-compensated X becomes enriched for hyperactive chromatin in males (mediated by H4K16ac), while the Y chromosome acquires silencing heterochromatin (enriched for H3K9me2/3). Drosophila autosomes are typically mostly euchromatic but the small dot chromosome has evolved a heterochromatin-like milieu (enriched for H3K9me2/3) that permits the normal expression of dot-linked genes, but which is different from typical pericentric heterochromatin. In Drosophila busckii, the dot chromosomes have fused to the ancestral sex chromosomes, creating a pair of ‘neo-sexchromosomes. Here we collect genomic, transcriptomic and epigenomic data from D. busckii, to investigate the evolutionary trajectory of sex chromosomes from a largely heterochromatic ancestor. We show that the neo-sex chromosomes formed <1 million years ago, but nearly 60% of neo-Y linked genes have already become non-functional. Expression levels are generally lower for the neo-Y alleles relative to their neo-X homologs, and the silencing heterochromatin mark H3K9me2, but not H3K9me3, is significantly enriched on silenced neo-Y genes. Despite rampant neo-Y degeneration, we find that the neo-X is deficient for the canonical histone modification mark of dosage compensation (H4K16ac), relative to autosomes or the compensated ancestral X chromosome, possibly reflecting constraints imposed on evolving hyperactive chromatin in an originally heterochromatic environment. Yet, neo-X genes are transcriptionally more active in males, relative to females, suggesting the evolution of incipient dosage compensation on the neo-X. Our data show that Y degeneration proceeds quickly after sex chromosomes become established through genomic and epigenetic changes, and are consistent with the idea that the evolution of sex-linked chromatin is influenced by its ancestral configuration. PMID:26114585

  13. The sex chromosomes of Silene latifolia revisited and revised.

    PubMed Central

    Lengerova, Martina; Moore, Richard C; Grant, Sarah R; Vyskot, Boris

    2003-01-01

    Classical studies have established that, during meiosis, the X and Y chromosomes of the model dioecious plant Silene latifolia pair over a region at the ends of their q arms. We used fluorescence in situ hybridization of two molecular markers to demonstrate that this widely accepted model is incorrect. From these data we conclude that the homologous arm of the X chromosome is the p arm and that of the Y chromosome is the q arm. The establishment of the proper orientation of the pseudoautosomal region is essential for mapping and evolutionary studies. PMID:14573500

  14. Sex differences in chiasma distribution along two marked mouse chromosomes: differences in chiasma distribution as a reason for sex differences in recombination frequency.

    PubMed

    Gorlov, I P; Zhelezova, A I; Gorlova OYu

    1994-12-01

    Chiasma distributions along bivalents 1 and 14 in female and male mice were studied. It was shown that the average chiasma number in both chromosomes show no sex difference. There are however, significant sex differences in chiasma distribution along 1 and 14 chromosomes. In males there are two terminal chiasma peaks in chromosome 1 and one subtelomeric peak of chiasmata in chromosome 14. In females chiasma distributions are more even. According to genetic data, females produce more recombinants between loci of chromosome 1 than males do. By means of a computer simulation it was demonstrated that the differences in the average recombination frequency result from differences in chiasma distribution. PMID:7698640

  15. DNA is organized into 46 chromosomes including sex chromosomes, 3D animation with no audioSite: DNA Interactive (www.dnai.org)

    NSDL National Science Digital Library

    2008-10-06

    The millions of bases, which make up the human genome are organized into structures called chromosomes. These are arranged into 22 matching pairs plus 1 pair of sex chromosomes consisting of 2 X's in women and an X and a Y in men. So humans have a total of 46 chromosomes in each cell, known collectively as a karyotype. This set of chromosomes has a Y, so it must belong to a male.

  16. Differentiated ZZ/ZW sex chromosomes in Apareiodon ibitiensis (Teleostei, Parodontidae): cytotaxonomy and biogeography.

    PubMed

    Bellafronte, E; Vicari, M R; Artoni, R F; Margarido, V P; Moreira-Filho, O

    2009-12-01

    Conventional and molecular chromosomal analyses were carried out on three populations of Apareiodon ibitiensis sampled from the hydrographic basins of the Săo Francisco River and Upper Paraná River (Brazil). The results reveal a conserved diploid number (2n = 54 chromosomes), a karyotype formula consisting of 50 m-sm + 4st and a ZZ/ZW sex chromosome system that has not been previously identified for the species. C-banding analysis with propidium iodide staining revealed centromeric and terminal bands located in the chromosomes of the specimens from the three populations and allowed the identification of heteromorphism of heterochromatin regions in the Z and W chromosomes. The number of 18S sites located through fluorescent in situ hybridization (FISH) varied between the populations of the Săo Francisco and Upper Paraná Rivers. The location of 5S rDNA sites proved comparable in one pair of metacentric chromosomes. Thus, the present study proposes a ZZ/ZW sex chromosome system for A. ibitiensis among the Parodontidae, and a hypothesis is presented regarding possible W chromosome differentiation stages in this species through DNA accumulation, showing geographical variations for this characteristic, possibly as a consequence of geographical reproductive isolation. PMID:20738689

  17. Sex-specific SCAR markers in the dioecious plant Rumex nivalis (Polygonaceae) and implications for the evolution of sex chromosomes.

    PubMed

    Stehlik, I; Blattner, F R

    2004-01-01

    We developed SCAR primers based on isolated and sequenced male-specific fragments as identified in an AFLP analysis of the dioecious plant Rumex nivalis. PCR amplification using these primers on females and males resulted in fragments exclusively present in males. Co-amplification of the nuclear rDNA internal transcribed spacer 2 together with the male-specific fragment was applied as an internal control for successful PCR reactions to avoid false-negative sex scoring. With a length of about 164 bp, the AFLP fragment was of a similar size as the tandemly arranged, repetitive sequences of 180 bp located on the Y chromosomes of Rumex acetosa. The genetic distances between the Y-chromosomal sequences of R. nivalis and R. acetosa, both members of the section Acetosa, were substantial. We found intra-individual divergence among cloned sequences of the male-specific fragment in R. nivalis. The patterns of interspecific and intra-individual sequence variation found are in accordance with proposed modes of the evolution of sex chromosomes. Y chromosomes possibly arose only once in the genus Rumex and consist mainly of heterochromatic DNA. Due to the almost complete absence of selection on them, Y chromosomes are likely to accumulate large numbers of mutations. PMID:13679980

  18. THE EVOLUTIONARY DYNAMICS OF SEXUALLY ANTAGONISTIC MUTATIONS IN PSEUDOAUTOSOMAL REGIONS OF SEX CHROMOSOMES

    PubMed Central

    Charlesworth, Brian; Jordan, Crispin Y; Charlesworth, Deborah; Glemin, S

    2014-01-01

    Sex chromosomes can evolve gene contents that differ from the rest of the genome, as well as larger sex differences in gene expression compared with autosomes. This probably occurs because fully sex-linked beneficial mutations substitute at different rates from autosomal ones, especially when fitness effects are sexually antagonistic (SA). The evolutionary properties of genes located in the recombining pseudoautosomal region (PAR) of a sex chromosome have not previously been modeled in detail. Such PAR genes differ from classical sex-linked genes by having two alleles at a locus in both sexes; in contrast to autosomal genes, however, variants can become associated with gender. The evolutionary fates of PAR genes may therefore differ from those of either autosomal or fully sex-linked genes. Here, we model their evolutionary dynamics by deriving expressions for the selective advantages of PAR gene mutations under different conditions. We show that, unless selection is very strong, the probability of invasion of a population by an SA mutation is usually similar to that of an autosomal mutation, unless there is close linkage to the sex-determining region. Most PAR genes should thus evolve similarly to autosomal rather than sex-linked genes, unless recombination is very rare in the PAR. PMID:24476564

  19. Genetic and functional analysis of DD44, a sex-linked gene from the dioecious plant Silene latifolia, provides clues to early events in sex chromosome evolution.

    PubMed Central

    Moore, Richard C; Kozyreva, Olga; Lebel-Hardenack, Sabine; Siroky, Jiri; Hobza, Roman; Vyskot, Boris; Grant, Sarah R

    2003-01-01

    Silene latifolia is a dioecious plant with heteromorphic sex chromosomes. The sex chromosomes of S. latifolia provide an opportunity to study the early events in sex chromosome evolution because of their relatively recent emergence. In this article, we present the genetic and physical mapping, expression analysis, and molecular evolutionary analysis of a sex-linked gene from S. latifolia, DD44 (Differential Display 44). DD44 is homologous to the oligomycin sensitivity-conferring protein, an essential component of the mitochondrial ATP synthase, and is ubiquitously expressed in both sexes. We have been able to genetically map DD44 to a region of the Y chromosome that is genetically linked to the carpel-suppressing locus. Although we have physically mapped DD44 to the distal end of the long arm of the X chromosome using fluorescence in situ hybridization (FISH), DD44 maps to the opposite arm of the Y chromosome as determined by our genetic map. These data suggest that chromosomal rearrangements have occurred on the Y chromosome, which may have contributed to the genetic isolation of the Y chromosome. We discuss the implications of these results with respect to the structural and functional evolution of the S. latifolia Y chromosome. PMID:12586719

  20. The mechanisms underlying sexual differentiation of behavior and physiology in mammals and birds: relative contributions of sex steroids and sex chromosomes

    PubMed Central

    Maekawa, Fumihiko; Tsukahara, Shinji; Kawashima, Takaharu; Nohara, Keiko; Ohki-Hamazaki, Hiroko

    2014-01-01

    From a classical viewpoint, sex-specific behavior and physiological functions as well as the brain structures of mammals such as rats and mice, have been thought to be influenced by perinatal sex steroids secreted by the gonads. Sex steroids have also been thought to affect the differentiation of the sex-typical behavior of a few members of the avian order Galliformes, including the Japanese quail and chickens, during their development in ovo. However, recent mammalian studies that focused on the artificial shuffling or knockout of the sex-determining gene, Sry, have revealed that sex chromosomal effects may be associated with particular types of sex-linked differences such as aggression levels, social interaction, and autoimmune diseases, independently of sex steroid-mediated effects. In addition, studies on naturally occurring, rare phenomena such as gynandromorphic birds and experimentally constructed chimeras in which the composition of sex chromosomes in the brain differs from that in the other parts of the body, indicated that sex chromosomes play certain direct roles in the sex-specific differentiation of the gonads and the brain. In this article, we review the relative contributions of sex steroids and sex chromosomes in the determination of brain functions related to sexual behavior and reproductive physiology in mammals and birds. PMID:25177264

  1. Independent fusions and recent origins of sex chromosomes in the evolution and diversification of glass knife fishes (Eigenmannia)

    Microsoft Academic Search

    F Henning; C B Moysés; D Calcagnotto; A Meyer; L F de Almeida-Toledo; LF de Almeida-Toledo

    2011-01-01

    The genus Eigenmannia comprises several species groups that display a surprising variety of diploid chromosome numbers and sex-determining systems. In this study, hypotheses regarding phylogenetic relationships and karyotype evolution were investigated using a combination of molecular and cytogenetic methods. Phylogenetic relationships were analyzed for 11 cytotypes based on sequences from five mitochondrial DNA regions. Parsimony-based character mapping of sex chromosomes

  2. Epidemiology of double aneuploidies involving chromosome 21 and the sex chromosomes.

    PubMed

    Kovaleva, Natalia V; Mutton, David E

    2005-04-01

    The chance of two chromosome abnormalities occurring in one conceptus is very small. However, some authors have suggested that double aneuplodies (DAs) might be more common than the product of their individual frequencies. The nonrandomness of such DA events was considered to be evidence that nondisjunction (NDJ) may be genetically determined. Data collected from the National Down syndrome Cytogenetic Register (NDSCR) in England and Wales and from the literature indicate that the frequencies of all nonmosaic DAs, except for 48,XXY,+21, are lower than expected, probably because of strong intrauterine selection against such pregnancies. Collectively, we identified 52 cases of nonmosaic 48,XXY,+21; 28 cases of 48,XYY,+21; and 14 cases of 48,XXX,+21 in liveborns and 13 cases of 48,XXY,+21; four cases of 48,XYY,+21; and two cases of 48,XXX,+21 after prenatal diagnoses. Among these cases, analysis of the published unbiased cytogenetic surveys of liveborn DS revealed 24 cases of 48,XXY,+21; nine cases of 48,XYY,+21; and seven cases of 48,XXX,+21. These figures are different from the expected proportion of 1:1:1 (P < 0.001), with carriers of XXY overrepresented in the group of carriers of DA. Mechanisms put forth to account for the higher occurrence of 48,XXY,+21 may include greater accessibility of disomic ovum to Y-carrying sperm, and promotion of NDJ in ovum by Y-bearing sperm. 48,XXY,+21 DA was found to be age-dependent, as the proportion of mothers over age 35 (x = 33.0) was increased over the general population. This is in contrast to the apparently age-independent 48,XYY,+21 DA, with a mean maternal age of 24.7 (P < 0.001). Paternal ages were also remarkably different between the groups, with a mean age of 37.9 in 48,XXY,+21 cases and a mean age of 27.9 in 48,XYY,+21 cases (P < 0.01). Maternal age-related factors, rather than genetic predisposition, may play a more important role in the etiology of the most common DA, 48,XXY,+21. PMID:15704133

  3. Sex ratio in normal and disomic sperm: Evidence that the extra chromosome 21 preferentially segregates with the Y chromosome

    SciTech Connect

    Griffin, D.K.; Millie, E.A.; Hassold, T.J. [Case Western Univ., Cleveland, OH (United States)]|[Univ. Hospitals of Cleveland, OH (United States)] [and others

    1996-11-01

    In humans, deviations from a 1:1 male:female ratio have been identified in both chromosomally normal and trisomic live births: among normal newborns there is a slight excess of males, among trisomy 18 live borns a large excess of females, and among trisomy 21 live borns an excess of males. These differences could arise from differential production of or fertilization by Y- or X-bearing sperm or from selection against male or female conceptions. To examine the proportion of Y- and X- bearing sperm in normal sperm and in sperm disomic for chromosomes 18 or 21, we used three-color FISH (to the X and Y and either chromosome 18 or chromosome 21) to analyze > 300,000 sperm from 24 men. In apparently normal sperm, the sex ratio was nearly 1:1 (148,074 Y-bearing to 148,657 X-bearing sperm), and the value was not affected by the age of the donor. Certain of the donors, however, had significant excesses of Y- or X-bearing sperm. In disomy 18 sperm, there were virtually identical numbers of Y- and X-bearing sperm; thus, the excess of females in trisomy 18 presumably is due to selection against male trisomic conceptions. In contrast, we observed 69 Y-bearing and 44 X-bearing sperm disomic for chromosome 21. This is consistent with previous molecular studies, which have identified an excess of males among paternally derived cases of trisomy 21, and suggests that some of the excess of males among Down syndrome individuals is attributable to a nondisjunctional mechanism in which the extra chromosome 21 preferentially segregates with the Y chromosome. 17 refs., 2 tabs.

  4. Molecular cytogenetic characterization of Rumex papillaris , a dioecious plant with an XX\\/XY 1 Y 2 sex chromosome system

    Microsoft Academic Search

    Rafael Navajas-Pérez; Trude Schwarzacher; Manuel Ruiz Rejón; Manuel A. Garrido-Ramos

    2009-01-01

    Rumex papillaris Boiss, & Reut., an Iberian endemic, belongs to the section Acetosa of the genus Rumex whose main representative is R. acetosa L., a species intensively studied in relation to sex-chromosome evolution. Here, we characterize cytogenetically the chromosomal\\u000a complement of R. papillaris in an effort to enhance future comparative genomic approaches and to better our understanding of sex chromosome

  5. The multiple sex chromosomes of platypus and echidna are not completely identical and several share homology with the avian Z

    PubMed Central

    Rens, Willem; O'Brien, Patricia CM; Grützner, Frank; Clarke, Oliver; Graphodatskaya, Daria; Tsend-Ayush, Enkhjargal; Trifonov, Vladimir A; Skelton, Helen; Wallis, Mary C; Johnston, Steve; Veyrunes, Frederic; Graves, Jennifer AM; Ferguson-Smith, Malcolm A

    2007-01-01

    Background Sex-determining systems have evolved independently in vertebrates. Placental mammals and marsupials have an XY system, birds have a ZW system. Reptiles and amphibians have different systems, including temperature-dependent sex determination, and XY and ZW systems that differ in origin from birds and placental mammals. Monotremes diverged early in mammalian evolution, just after the mammalian clade diverged from the sauropsid clade. Our previous studies showed that male platypus has five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome. In order to investigate monotreme sex chromosome evolution, we performed a comparative study of platypus and echidna by chromosome painting and comparative gene mapping. Results Chromosome painting reveals a meiotic chain of nine sex chromosomes in the male echidna and establishes their order in the chain. Two of those differ from those in the platypus, three of the platypus sex chromosomes differ from those of the echidna and the order of several chromosomes is rearranged. Comparative gene mapping shows that, in addition to bird autosome regions, regions of bird Z chromosomes are homologous to regions in four platypus X chromosomes, that is, X1, X2, X3, X5, and in chromosome Y1. Conclusion Monotreme sex chromosomes are easiest to explain on the hypothesis that autosomes were added sequentially to the translocation chain, with the final additions after platypus and echidna divergence. Genome sequencing and contig anchoring show no homology yet between platypus and therian Xs; thus, monotremes have a unique XY sex chromosome system that shares some homology with the avian Z. PMID:18021405

  6. The Sex Chromosomes of Silene latifolia Revisited and Revised

    Microsoft Academic Search

    Martina Lengerova; Richard C. Moore; Sarah R. Grant; Boris Vyskot

    2003-01-01

    Classical studies have established that, during meiosis, the X and Y chromosomes of the model dioecious plant Silene latifolia pair over a region at the ends of their q arms. We used fluorescence in situ hybridization of two molecular markers to demonstrate that this widely accepted model is incorrect. From these data we conclude that the homologous arm of the

  7. Sequencing chromosomal abnormalities reveals neurodevelopmental loci that confer risk across diagnostic boundaries

    PubMed Central

    Talkowski, Michael E.; Rosenfeld, Jill A.; Blumenthal, Ian; Pillalamarri, Vamsee; Chiang, Colby; Heilbut, Adrian; Ernst, Carl; Hanscom, Carrie; Rossin, Elizabeth; Lindgren, Amelia; Pereira, Shahrin; Ruderfer, Douglas; Kirby, Andrew; Ripke, Stephan; Harris, David; Lee, Ji-Hyun; Ha, Kyungsoo; Kim, Hyung-Goo; Solomon, Benjamin D.; Gropman, Andrea L.; Lucente, Diane; Sims, Katherine; Ohsumi, Toshiro K.; Borowsky, Mark L.; Loranger, Stephanie; Quade, Bradley; Lage, Kasper; Miles, Judith; Wu, Bai-Lin; Shen, Yiping; Neale, Benjamin; Shaffer, Lisa G.; Daly, Mark J.; Morton, Cynthia C.; Gusella, James F.

    2012-01-01

    SUMMARY Balanced chromosomal abnormalities (BCAs) represent a reservoir of single gene disruptions in neurodevelopmental disorders (NDD). We sequenced BCAs in autism and related NDDs, revealing disruption of 33 loci in four general categories: 1) genes associated with abnormal neurodevelopment (e.g., AUTS2, FOXP1, CDKL5), 2) single gene contributors to microdeletion syndromes (MBD5, SATB2, EHMT1, SNURF-SNRPN), 3) novel risk loci (e.g., CHD8, KIRREL3, ZNF507), and 4) genes associated with later onset psychiatric disorders (e.g., TCF4, ZNF804A, PDE10A, GRIN2B, ANK3). We also discovered profoundly increased burden of copy number variants among 19,556 neurodevelopmental cases compared to 13,991 controls (p = 2.07×10?47) and enrichment of polygenic risk alleles from autism and schizophrenia genome-wide association studies (p = 0.0018 and 0.0009, respectively). Our findings suggest a polygenic risk model of autism incorporating loci of strong effect and indicate that some neurodevelopmental genes are sensitive to perturbation by multiple mutational mechanisms, leading to variable phenotypic outcomes that manifest at different life stages. PMID:22521361

  8. Amniotic fluid-AFP in Down syndrome and other chromosome abnormalities.

    PubMed

    Crandall, B F; Matsumoto, M; Perdue, S

    1988-05-01

    80.2 Per cent of 111 Down syndrome pregnancies had anmiotic fluid (AF) alpha fetoprotein (AFP) levels on or below the median and 10.8 per cent at or below 0.5 MoM compared with 41.9 and 1.4 per cent of controls. These differences were even more striking when the gestational age was less than 18 weeks compared with greater than or equal to 18 weeks. No such association was seen for other chromosome abnormalities including trisomy 18,45,X and mosaics, 47,XXY,47,XXX, and other structural abnormalities and triploidy, even when high levels due to defects such as omphalocele and cystic hygroma were excluded. All cases of trisomy 13 and 80 per cent with 47,XYY had AF-AFP levels above the median. Selection of cases for karyotyping by a low level of AF-AFP would clearly fail to detect aneuploidies other than Down syndrome and is not recommended. A possible weak association between low maternal serum (MS) and AF-AFPs in Down syndrome was most evident at less than 18 weeks, suggesting that MS screening between 16 and 18 weeks may be the most informative time. PMID:2456565

  9. Sequencing chromosomal abnormalities reveals neurodevelopmental loci that confer risk across diagnostic boundaries.

    PubMed

    Talkowski, Michael E; Rosenfeld, Jill A; Blumenthal, Ian; Pillalamarri, Vamsee; Chiang, Colby; Heilbut, Adrian; Ernst, Carl; Hanscom, Carrie; Rossin, Elizabeth; Lindgren, Amelia M; Pereira, Shahrin; Ruderfer, Douglas; Kirby, Andrew; Ripke, Stephan; Harris, David J; Lee, Ji-Hyun; Ha, Kyungsoo; Kim, Hyung-Goo; Solomon, Benjamin D; Gropman, Andrea L; Lucente, Diane; Sims, Katherine; Ohsumi, Toshiro K; Borowsky, Mark L; Loranger, Stephanie; Quade, Bradley; Lage, Kasper; Miles, Judith; Wu, Bai-Lin; Shen, Yiping; Neale, Benjamin; Shaffer, Lisa G; Daly, Mark J; Morton, Cynthia C; Gusella, James F

    2012-04-27

    Balanced chromosomal abnormalities (BCAs) represent a relatively untapped reservoir of single-gene disruptions in neurodevelopmental disorders (NDDs). We sequenced BCAs in patients with autism or related NDDs, revealing disruption of 33 loci in four general categories: (1) genes previously associated with abnormal neurodevelopment (e.g., AUTS2, FOXP1, and CDKL5), (2) single-gene contributors to microdeletion syndromes (MBD5, SATB2, EHMT1, and SNURF-SNRPN), (3) novel risk loci (e.g., CHD8, KIRREL3, and ZNF507), and (4) genes associated with later-onset psychiatric disorders (e.g., TCF4, ZNF804A, PDE10A, GRIN2B, and ANK3). We also discovered among neurodevelopmental cases a profoundly increased burden of copy-number variants from these 33 loci and a significant enrichment of polygenic risk alleles from genome-wide association studies of autism and schizophrenia. Our findings suggest a polygenic risk model of autism and reveal that some neurodevelopmental genes are sensitive to perturbation by multiple mutational mechanisms, leading to variable phenotypic outcomes that manifest at different life stages. PMID:22521361

  10. Spatial Dynamics of Evolving Dosage Compensation in a Young Sex Chromosome System

    PubMed Central

    Schultheiß, Roland; Viitaniemi, Heidi M.; Leder, Erica H.

    2015-01-01

    The loss of Y-linked genes during sex chromosome evolution creates a potentially deleterious low gene dosage in males. Recent studies have reported different strategies of dosage compensation. Unfortunately, most of these studies investigated taxa with comparatively old sex chromosome systems, which may limit insights into the evolution of dosage compensation and thus into the causes of different compensation strategies. Using deep RNA sequencing, we investigate differential expression patterns along the young XY chromosomes of threespine sticklebacks. Our strata-specific analyses provide new insights into the spatial patterns during the early stages of the evolution of dosage compensation. In particular, our results indicate systematic upregulation of male gene expression in stratum II, which in turn causes female hypertranscription in the same stratum. These findings are consistent with theoretical predictions that selection during early stages of sex chromosome evolution is stronger for a compensating upregulation in males than for the countercompensation of female hyperexpression. In contrast, no elevated gene expression is detectable in stratum I. We argue that strata-specific differences in compensating male gene expression may evolve in response to differences in the prevailing mechanism of Y chromosome degeneration. PMID:25618140

  11. Linkage analysis reveals independent origin of Poeciliid sex chromosomes and a case of atypical

    E-print Network

    Weigel, Detlef

    Articles Ahead of Print, published on March 18, 2009 as 10.1534/genetics.108.098541 #12;2 Running title Among different teleost fish species, diverse sex determining mechanisms exist including environmental chromosomes identified in various fish species so far are considered to be at an early stage

  12. Convergent Evolution of Chromosomal Sex-Determining Regions in the Animal and Fungal Kingdoms

    Microsoft Academic Search

    James A Fraser; Stephanie Diezmann; Ryan L Subaran; Andria Allen; Klaus B Lengeler; Fred S Dietrich; Joseph Heitman

    2004-01-01

    Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT) loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen Cryptococcus revealed sequential evolutionary events that fashioned this large, highly unusual region. We hypothesize that MAT evolved via four main steps, beginning with acquisition of genes

  13. Genomic identification and characterization of the pseudoautosomal region in highly differentiated avian sex chromosomes

    PubMed Central

    Smeds, Linnéa; Kawakami, Takeshi; Burri, Reto; Bolivar, Paulina; Husby, Arild; Qvarnström, Anna; Uebbing, Severin; Ellegren, Hans

    2014-01-01

    The molecular characteristics of the pseudoautosomal region (PAR) of sex chromosomes remain elusive. Despite significant genome-sequencing efforts, the PAR of highly differentiated avian sex chromosomes remains to be identified. Here we use linkage analysis together with whole-genome re-sequencing to uncover the 630-kb PAR of an ecological model species, the collared flycatcher. The PAR contains 22 protein-coding genes and is GC rich. The genetic length is 64?cM in female meiosis, consistent with an obligate crossing-over event. Recombination is concentrated to a hotspot region, with an extreme rate of >700?cM/Mb in a 67-kb segment. We find no signatures of sexual antagonism and propose that sexual antagonism may have limited influence on PAR sequences when sex chromosomes are nearly fully differentiated and when a recombination hotspot region is located close to the PAR boundary. Our results demonstrate that a very small PAR suffices to ensure homologous recombination and proper segregation of sex chromosomes during meiosis. PMID:25378102

  14. Evidence that Sex Chromosome Genes Affect Sexual Differentiation of Female Sexual Behavior

    PubMed Central

    Grgurevic, Neza; Büdefeld, Tomaz; Spanic, Tanja; Tobet, Stuart; Majdic, Gregor

    2012-01-01

    Female receptivity including the immobile hormone-dependent lordosis posture is essential for successful reproduction in rodents. It is well documented that lordosis is organized during the perinatal period when the actions of androgens decrease the males’ ability to display this behavior in adulthood. Conversely the absence of androgens, and the presence of low levels of prepubertal estrogens, preserves circuitry that regulates this behavior in females. The current study set out to determine whether sex chromosomal genes are involved in the differentiation of this behavior. An agonadal mouse model was used to test this hypothesis. The SF-1 gene (Nr5a1) is required for development of gonads and adrenal glands, and knockout mice are consequently not exposed to endogenous gonadal steroids. Thus contributions of sex chromosome genes can be disassociated from the actions of estrogens. Use of this model reveals a direct genetic contribution from sex chromosomes in the display of lordosis and other female-typical sexual behavior patterns. It is likely that the concentrations of gonadal steroids present during normal male development modify the actions of sex chromosome genes on the potential to display female sexual behavior. PMID:22483977

  15. Accumulation of Y-specific satellite DNAs during the evolution of Rumex acetosa sex chromosomes.

    PubMed

    Mariotti, Beatrice; Manzano, Susana; Kejnovský, Eduard; Vyskot, Boris; Jamilena, Manuel

    2009-03-01

    The study of the molecular structure of young heteromorphic sex chromosomes of plants has shed light on the evolutionary forces that control the differentiation of the X and Y during the earlier stages of their evolution. We have used the model plant Rumex acetosa, a dioecious species with multiple sex chromosomes, 2n = 12 + XX female and 2n = 12 + XY(1)Y(2) male, to analyse the significance of repetitive DNA accumulation during the differentiation of the Y. A bulk segregant analysis (BSA) approach allowed us to identify and isolate random amplified polymorphic DNA (RAPD) markers linked to the sex chromosomes. From a total of 86 RAPD markers in the parents, 6 markers were found to be linked to the Ys and 1 to the X. Two of the Y-linked markers represent two AT-rich satellite DNAs (satDNAs), named RAYSII and RAYSIII, that share about 80% homology, as well as with RAYSI, another satDNA of R. acetosa. Fluorescent in situ hybridisation demonstrated that RAYSII is specific for Y(1), whilst RAYSIII is located in different clusters along Y(1) and Y(2). The two satDNAs were only detected in the genome of the dioecious species with XX/XY(1)Y(2) multiple sex chromosome systems in the subgenus Acetosa, but were absent from other dioecious species with an XX/XY system of the subgenera Acetosa or Acetosella, as well as in gynodioecious or hermaphrodite species of the subgenera Acetosa, Rumex and Platypodium. Phylogenetic analysis with different cloned monomers of RAYSII and RAYSIII from both R. acetosa and R. papillaris indicate that these two satDNAs are completely separated from each other, and from RAYSI, in both species. The three Y-specific satDNAs, however, evolved from an ancestral satDNA with repeating units of 120 bp, through intermediate satDNAs of 360 bp. The data therefore support the idea that Y-chromosome differentiation and heterochromatinisation in the Rumex species having a multiple sex chromosome system have occurred by different amplification events from a common ancestral satDNA. Since dioecious species with multiple XX/XY(1)Y(2) sex chromosome systems of the section Acetosa appear to have evolved from dioecious species with an XX/XY system, the amplification of tandemly repetitive elements in the Ys of the section Acetosa is a recent evolutionary process that has contributed to an increase in the size and differentiation of the already non-recombining Y chromosomes. PMID:19085011

  16. H2AX Is Required for Chromatin Remodeling and Inactivation of Sex Chromosomes in Male Mouse Meiosis

    Microsoft Academic Search

    Oscar Fernandez-Capetillo; Shantha K. Mahadevaiah; Arkady Celeste; Peter J. Romanienko; R. Daniel Camerini-Otero; William M. Bonner; Katia Manova; Paul Burgoyne; André Nussenzweig

    2003-01-01

    During meiotic prophase in male mammals, the X and Y chromosomes condense to form a macrochromatin body, termed the sex, or XY, body, within which X- and Y-linked genes are transcriptionally repressed. The molecular basis and biological function of both sex body formation and meiotic sex chromosome inactivation (MSCI) are unknown. A phosphorylated form of H2AX, a histone H2A variant

  17. 118 VOLUME 21 NUMBER 2 FEBRUARY 2014 nature structural & molecular biology In many animal species, the chromosomal basis for sex has led to

    E-print Network

    Cai, Long

    118 VOLUME 21 NUMBER 2 FEBRUARY 2014 nature structural & molecular biology In many animal species, the chromosomal basis for sex has led to specific evolutionary pressures on the chromosomes containing sex- determination genes. It is commonly thought that heterologous sex chromosomes evolved as a consequence

  18. An unusual cytogenetic rearrangement originating from two different abnormalities in chromosome 6 in a child with acute promyelocytic leukemia.

    PubMed

    Matos, R R C; Mkrtchyan, H; Amaral, B A S; Liehr, T; de Souza, M T; Ney-Garcia, D R; Santos, N; Marques-Salles, T J; Ribeiro, R C; Figueiredo, A F; Silva, M L M

    2013-01-01

    Acute promyelocytic leukemia (APL) is usually associated with a favorable outcome, but about 10% of patients tend to relapse. The genetic hallmark of APL is a balanced translocation involving chromosomes 15 and 17, and the PML-RARa gene fusion is found in more than 90% of these cases. Other chromosomal abnormalities are commonly found in APL, but their clinical significance has yet to be determined. Here we report a case of childhood APL that was studied by conventional cytogenetics along with molecular cytogenetic techniques. The patient showed a complex karyotype with an unusual cytogenetic rearrangement originating from two different abnormalities in a single chromosome 6. Our case is an exceptional example of a cryptic cytogenetic anomaly in APL and underscores the importance of detailed genetic characterization. PMID:23363773

  19. Genome structure and emerging evidence of an incipient sex chromosome in Populus

    SciTech Connect

    Yin, Tongming [ORNL; DiFazio, Stephen P [West Virginia University; Gunter, Lee E [ORNL; Zhang, Xinye [ORNL; Sewell, Mitchell [ORNL; Woolbright, Dr. Scott [North Arizona University; Allan, Dr. Gery [North Arizona University; Kelleher, Colin [University of British Columbia, Vancouver; Douglas, Carl [University of British Columbia, Vancouver; Wang, Prof. Mingxiu [Nanjing Forestry University, China; Tuskan, Gerald A [ORNL

    2008-01-01

    The genus Populus consists of dioecious woody species with largely unknown genetic mechanisms for gender determination. We have discovered genetic and genomic features in the peritelomeric region of chromosome XIX that suggest this region of the Populus genome is in the process of developing characteristics of a sex chromosome. We have identified a gender-associated locus that consistently maps to this region. Furthermore, comparison of genetic maps across multiple Populus families reveals consistently distorted segregation within this region. We have intensively characterized this region using an F1 interspecific cross involving the female genotype that was used for genome sequencing. This region shows suppressed recombination and high divergence between the alternate haplotypes, as revealed by dense map-based genome assembly using microsatellite markers. The suppressed recombination, distorted segregation, and haplotype divergence were observed only for the maternal parent in this cross. Furthermore, the progeny of this cross showed a strongly male-biased sex ratio, in agreement with Haldane's rule that postulates that the heterogametic sex is more likely to be absent, rare, or sterile in interspecific crosses. Together, these results support the role of chromosome XIX in sex determination and suggest that sex determination in Populus occurs through a ZW system in which the female is the heterogametic gender.

  20. Chromosomally abnormal cells are not selected for the extra-embryonic compartment of the human preimplantation embryo at the blastocyst stage

    Microsoft Academic Search

    Josien G. Derhaag; Edith Coonen; Marijke Bras; J. Marij; Bergers Janssen; Rosie Ignoul-Vanvuchelen; Joep P. M. Geraedts; Johannes L. H. Evers; John C. M. Dumoulin

    2003-01-01

    BACKGROUND: Although well defined for embryos at cleavage stages, the occurrence and frequency of chromosomal aberrations in human blastocysts is relatively unknown. It has been reported that only one in four blastocysts is comprised totally of chromosomally normal cells. One of the selection mechanisms for the embryo proper to become free of these chromosomally abnormal cells would be to sequester

  1. HUMAN MIXED LEUKOCYTE CULTURE: IDENTIFICATION OF THE PROLIFERATING LYMPHOCYTE SUBPOPULATION BY SEX CHROMOSOME MARKERS

    PubMed Central

    Lohrmann, Hans-Peter; Whang-Peng, Jacqueline

    1974-01-01

    The nature of the cells which proliferate in response to allogeneic histoincompatible lymphocytes in human mixed leukocyte cultures (MLC) was investigated. Direct information on the differentiation of proliferating cells was obtained in an in vitro chimeric system with T- and B-cell sex chromosome markers. Highly purified T and B cells were prepared from the peripheral blood of three pairs of HL-A genotype identical, MLC-negative siblings of opposite sex by E-rosette sedimentation techniques. Recombined T and B cells of the siblings were stimulated with allogeneic cells, and karyotype analysis of proliferating cells performed. 96% of the proliferating cells were found to carry the sex chromosome marker of the respective T-cell population. These results indicate that proliferation in human MLCs is a feature of T cells. PMID:4275829

  2. Sex-specific Trans-regulatory Variation on the Drosophila melanogaster X Chromosome

    PubMed Central

    Stocks, Michael; Dean, Rebecca; Rogell, Björn; Friberg, Urban

    2015-01-01

    The X chromosome constitutes a unique genomic environment because it is present in one copy in males, but two copies in females. This simple fact has motivated several theoretical predictions with respect to how standing genetic variation on the X chromosome should differ from the autosomes. Unmasked expression of deleterious mutations in males and a lower census size are expected to reduce variation, while allelic variants with sexually antagonistic effects, and potentially those with a sex-specific effect, could accumulate on the X chromosome and contribute to increased genetic variation. In addition, incomplete dosage compensation of the X chromosome could potentially dampen the male-specific effects of random mutations, and promote the accumulation of X-linked alleles with sexually dimorphic phenotypic effects. Here we test both the amount and the type of genetic variation on the X chromosome within a population of Drosophila melanogaster, by comparing the proportion of X linked and autosomal trans-regulatory SNPs with a sexually concordant and discordant effect on gene expression. We find that the X chromosome is depleted for SNPs with a sexually concordant effect, but hosts comparatively more SNPs with a sexually discordant effect. Interestingly, the contrasting results for SNPs with sexually concordant and discordant effects are driven by SNPs with a larger influence on expression in females than expression in males. Furthermore, the distribution of these SNPs is shifted towards regions where dosage compensation is predicted to be less complete. These results suggest that intrinsic properties of dosage compensation influence either the accumulation of different types of trans-factors and/or their propensity to accumulate mutations. Our findings document a potential mechanistic basis for sex-specific genetic variation, and identify the X as a reservoir for sexually dimorphic phenotypic variation. These results have general implications for X chromosome evolution, as well as the genetic basis of sex-specific evolutionary change. PMID:25679222

  3. A pseudoautosomal random amplified polymorphic DNA marker for the sex chromosomes of Silene dioica.

    PubMed Central

    Di Stilio, V S; Kesseli, R V; Mulcahy, D L

    1998-01-01

    The segregation pattern of an 810-bp random amplified polymorphic DNA (RAPD) band in the F1 and backcross generations of a Silene dioica (L.) Clairv. family provides evidence that this molecular marker is located in the pseudoautosomal region (PAR) of the X and Y chromosomes. The marker was found through a combination of bulked segregant analysis (BSA) and RAPD techniques. Recombination rates between this pseudoautosomal marker and the differentiating portion of the Y chromosome are 15% in both generations. Alternative explanations involving nondisjunction or autosomal inheritance are presented and discussed. Chromosome counts provide evidence against the nondisjunction hypothesis, and probability calculations argue against the possibility of autosomal inheritance. This constitutes the first report of a pseudoautosomal DNA marker for plant sex chromosomes. PMID:9691057

  4. A pseudoautosomal random amplified polymorphic DNA marker for the sex chromosomes of Silene dioica.

    PubMed

    Di Stilio, V S; Kesseli, R V; Mulcahy, D L

    1998-08-01

    The segregation pattern of an 810-bp random amplified polymorphic DNA (RAPD) band in the F1 and backcross generations of a Silene dioica (L.) Clairv. family provides evidence that this molecular marker is located in the pseudoautosomal region (PAR) of the X and Y chromosomes. The marker was found through a combination of bulked segregant analysis (BSA) and RAPD techniques. Recombination rates between this pseudoautosomal marker and the differentiating portion of the Y chromosome are 15% in both generations. Alternative explanations involving nondisjunction or autosomal inheritance are presented and discussed. Chromosome counts provide evidence against the nondisjunction hypothesis, and probability calculations argue against the possibility of autosomal inheritance. This constitutes the first report of a pseudoautosomal DNA marker for plant sex chromosomes. PMID:9691057

  5. Sequential Cross-Species Chromosome Painting among River Buffalo, Cattle, Sheep and Goat: A Useful Tool for Chromosome Abnormalities Diagnosis within the Family Bovidae

    PubMed Central

    Pauciullo, Alfredo; Perucatti, Angela; Cosenza, Gianfranco; Iannuzzi, Alessandra; Incarnato, Domenico; Genualdo, Viviana; Di Berardino, Dino; Iannuzzi, Leopoldo

    2014-01-01

    The main goal of this study was to develop a comparative multi-colour Zoo-FISH on domestic ruminants metaphases using a combination of whole chromosome and sub-chromosomal painting probes obtained from the river buffalo species (Bubalus bubalis, 2n?=?50,XY). A total of 13 DNA probes were obtained through chromosome microdissection and DOP-PCR amplification, labelled with two fluorochromes and sequentially hybridized on river buffalo, cattle (Bos taurus, 2n?=?60,XY), sheep (Ovis aries, 2n?=?54,XY) and goat (Capra hircus, 2n?=?60,XY) metaphases. The same set of paintings were then hybridized on bovine secondary oocytes to test their potential use for aneuploidy detection during in vitro maturation. FISH showed excellent specificity on metaphases and interphase nuclei of all the investigated species. Eight pairs of chromosomes were simultaneously identified in buffalo, whereas the same set of probes covered 13 out 30 chromosome pairs in the bovine and goat karyotypes and 40% of the sheep karyotype (11 out of 27 chromosome pairs). This result allowed development of the first comparative M-FISH karyotype within the domestic ruminants. The molecular resolution of complex karyotypes by FISH is particularly useful for the small chromosomes, whose similarity in the banding patterns makes their identification very difficult. The M-FISH karyotype also represents a practical tool for structural and numerical chromosome abnormalities diagnosis. In this regard, the successful hybridization on bovine secondary oocytes confirmed the potential use of this set of probes for the simultaneous identification on the same germ cell of 12 chromosome aneuploidies. This is a fundamental result for monitoring the reproductive health of the domestic animals in relation to management errors and/or environmental hazards. PMID:25330006

  6. Platypus chain reaction: directional and ordered meiotic pairing of the multiple sex chromosome chain in Ornithorhynchus anatinus.

    PubMed

    Daish, Tasman; Casey, Aaron; Grützner, Frank

    2009-01-01

    Monotremes are phylogenetically and phenotypically unique animals with an unusually complex sex chromosome system that is composed of ten chromosomes in platypus and nine in echidna. These chromosomes are alternately linked (X1Y1, X2Y2, ...) at meiosis via pseudoautosomal regions and segregate to form spermatozoa containing either X or Y chromosomes. The physical and epigenetic mechanisms involved in pairing and assembly of the complex sex chromosome chain in early meiotic prophase I are completely unknown. We have analysed the pairing dynamics of specific sex chromosome pseudoautosomal regions in platypus spermatocytes during prophase of meiosis I. Our data show a highly coordinated pairing process that begins at the terminal Y5 chromosome and completes with the union of sex chromosomes X1Y1. The consistency of this ordered assembly of the chain is remarkable and raises questions about the mechanisms and factors that regulate the differential pairing of sex chromosomes and how this relates to potential meiotic silencing mechanisms and alternate segregation. PMID:19874721

  7. Isolation of the human chromosome 22q telomere and its application to detection of cryptic chromosomal abnormalities

    Microsoft Academic Search

    Yi Ning; Marjorie Rosenberg; David H. Ledbetter; Leslie G. Biesecker

    1996-01-01

    A number of human telomeres have been successfully cloned using a modified yeast artificial chromosome (YAC) vector (half-YAC)\\u000a cloning strategy, but to date, human chromosome 22q has not been identified by this approach. We used an alternative approach\\u000a of genomic walking, starting from a subtelomeric sequence, TelBam3.4, present on a number of human chromosomes including 22q.\\u000a This approach was successful

  8. Biased Transmission of Sex Chromosomes in the Aphid Myzus persicae Is Not Associated with Reproductive Mode

    PubMed Central

    Wilson, Alex C. C.; Delgado, Ryan N.; Vorburger, Christoph

    2014-01-01

    Commonly, a single aphid species exhibits a wide range of reproductive strategies including cyclical parthenogenesis and obligate parthenogenesis. Sex determination in aphids is chromosomal; females have two X chromosomes, while males have one. X chromosome elimination at male production is generally random, resulting in equal representation of both X chromosomes in sons. However, two studies have demonstrated deviations from randomness in some lineages. One hypothesis to account for such deviations is that recessive deleterious mutations accumulate during bouts of asexual reproduction and affect male viability, resulting in overrepresentation of males with the least deleterious of the two maternal X chromosomes. This hypothesis results in a testable prediction: X chromosome transmission bias will increase with time spent in the asexual phase and should therefore be most extreme in the least sexual aphid life cycle class. Here we test this prediction in Myzus persicae. We used multiple heterozygous X-linked microsatellite markers to screen 1085 males from 95 lines of known life cycle. We found significant deviations from equal representation of X chromosomes in 15 lines; however, these lines included representatives of all life cycles. Our results are inconsistent with the hypothesis that deviations from randomness are attributable to mutation accumulation. PMID:25548924

  9. Laser microdissection-based analysis of the Y sex chromosome of the Antarctic fish Chionodraco hamatus (Notothenioidei, Channichthyidae)

    PubMed Central

    Cocca, Ennio; Petraccioli, Agnese; Morescalchi, Maria Alessandra; Odierna, Gaetano; Capriglione, Teresa

    2015-01-01

    Abstract Microdissection, DOP-PCR amplification and microcloning were used to study the large Y chromosome of Chionodraco hamatus, an Antarctic fish belonging to the Notothenioidei, the dominant component of the Southern Ocean fauna. The species has evolved a multiple sex chromosome system with digametic males showing an X1YX2 karyotype and females an X1X1X2X2 karyotype. Fluorescence in situ hybridization, performed with a painting probe made from microdissected Y chromosomes, allowed a deeper insight on the chromosomal rearrangement, which underpinned the fusion event that generated the Y. Then, we used a DNA library established by microdissection and microcloning of the whole Y chromosome of Chionodraco hamatus for searching sex-linked sequences. One clone provided preliminary information on the presence on the Y chromosome of the CHD1 gene homologue, which is sex-linked in birds but in no other vertebrates. Several clones from the Y-chromosome mini-library contained microsatellites and transposable elements, one of which mapped to the q arm putative fusion region of the Y chromosome. The findings confirm that interspersed repetitive sequences might have fostered chromosome rearrangements and the emergence of the Y chromosome in Chionodraco hamatus. Detection of the CHD1 gene in the Y sex-determining region could be a classical example of convergent evolution in action. PMID:25893071

  10. Sequence and gene content of a large fragment of a lizard sex chromosome and evaluation of candidate sex differentiating gene R-spondin 1

    PubMed Central

    2013-01-01

    Background Scant genomic information from non-avian reptile sex chromosomes is available, and for only a few lizards, several snakes and one turtle species, and it represents only a small fraction of the total sex chromosome sequences in these species. Results We report a 352 kb of contiguous sequence from the sex chromosome of a squamate reptile, Pogona vitticeps, with a ZZ/ZW sex microchromosome system. This contig contains five protein coding genes (oprd1, rcc1, znf91, znf131, znf180), and major families of repetitive sequences with a high number of copies of LTR and non-LTR retrotransposons, including the CR1 and Bov-B LINEs. The two genes, oprd1 and rcc1 are part of a homologous syntenic block, which is conserved among amniotes. While oprd1 and rcc1 have no known function in sex determination or differentiation in amniotes, this homologous syntenic block in mammals and chicken also contains R-spondin 1 (rspo1), the ovarian differentiating gene in mammals. In order to explore the probability that rspo1 is sex determining in dragon lizards, genomic BAC and cDNA clones were mapped using fluorescence in situ hybridisation. Their location on an autosomal microchromosome pair, not on the ZW sex microchromosomes, eliminates rspo1 as a candidate sex determining gene in P. vitticeps. Conclusion Our study has characterized the largest contiguous stretch of physically mapped sex chromosome sequence (352 kb) from a ZZ/ZW lizard species. Although this region represents only a small fraction of the sex chromosomes of P. vitticeps, it has revealed several features typically associated with sex chromosomes including the accumulation of large blocks of repetitive sequences. PMID:24344927

  11. The Sex Chromosome Trisomy mouse model of XXY and XYY: metabolism and motor performance

    PubMed Central

    2013-01-01

    Background Klinefelter syndrome (KS), caused by XXY karyotype, is characterized by low testosterone, infertility, cognitive deficits, and increased prevalence of health problems including obesity and diabetes. It has been difficult to separate direct genetic effects from hormonal effects in human studies or in mouse models of KS because low testosterone levels are confounded with sex chromosome complement. Methods In this study, we present the Sex Chromosome Trisomy (SCT) mouse model that produces XXY, XYY, XY, and XX mice in the same litters, each genotype with either testes or ovaries. The independence of sex chromosome complement and gonadal type allows for improved recognition of sex chromosome effects that are not dependent on levels of gonadal hormones. All mice were gonadectomized and treated with testosterone for 3 weeks. Body weight, body composition, and motor function were measured. Results Before hormonal manipulation, XXY mice of both sexes had significantly greater body weight and relative fat mass compared to XY mice. After gonadectomy and testosterone replacement, XXY mice (both sexes) still had significantly greater body weight and relative fat mass, but less relative lean mass compared to XY mice. Liver, gonadal fat pad, and inguinal fat pad weights were also higher in XXY mice, independent of gonadal sex. In several of these measures, XX mice also differed from XY mice, and gonadal males and females differed significantly on almost every metabolic measure. The sex chromosome effects (except for testis size) were also seen in gonadally female mice before and after ovariectomy and testosterone treatment, indicating that they do not reflect group differences in levels of testicular secretions. XYY mice were similar to XY mice on body weight and metabolic variables but performed worse on motor tasks compared to other groups. Conclusions We find that the new SCT mouse model for XXY and XYY recapitulates features found in humans with these aneuploidies. We illustrate that this model has significant promise for unveiling the role of genetic effects compared to hormonal effects in these syndromes, because many phenotypes are different in XXY vs. XY gonadal female mice which have never been exposed to testicular secretions. PMID:23926958

  12. Genetic marking of sex using a W chromosome-linked transgene.

    PubMed

    Ma, Sanyuan; Wang, Xiaogang; Fei, Jitao; Liu, Yuanyuan; Duan, Jianping; Wang, Feng; Xu, Hanfu; Zhao, Ping; Xia, Qingyou

    2013-12-01

    Many species belonging to the order Lepidoptera are major pests in agriculture and arboriculture. The sterile insect technique (SIT) is an eco-friendly and highly efficient genetically targeted pest management approach. In many cases, it is preferable to release only sterile males in an SIT program, and efficient sexing strategies are crucial to the successful large-scale implementation of SIT. In the present study, we established 160 transgenic silkworm (Bombyx mori) lines to test the possibility of genetic sexing using a W chromosome-linked transgene, which is thought to be the best sexing strategy for lepidopteran species. One transgenic line with a female-specific expression pattern of reporter gene was obtained. The expression level of the W-linked transgene was comparable with autosomal insertions and was stable for 17 continuous generations. Molecular characterization showed this line contained a single copy of the reporter gene on the W chromosome, and the integration site was TTAG in contig W-BAC-522N19-C9. The feasibility of using a W chromosome-linked transgene demonstrated here and the possible improvements discussed will provide valuable information for other lepidopteran pests. The novel W chromosome-linked transgenic line established in this study will serve as an important resource for fundamental research with the silkworm B. mori. PMID:24036279

  13. Establishment of a 10-Plex Quantitative Fluorescent-PCR Assay for Rapid Diagnosis of Sex Chromosome Aneuploidies

    PubMed Central

    Xie, Xingmei; Liang, Qiaoyi

    2014-01-01

    Sex chromosome aneuploidies occur commonly in the general population, with an incidence of 1 in 400 newborns. However, no tests specifically targeting sex chromosomes have been carried out in prenatal diagnosis or newborn screening, resulting in late recognition of these diseases. In this study, a rapid diagnostic method for sex chromosome aneuploidies was established using Quantitative Fluorescent-PCR (QF-PCR). Ten markers were included in one multiplex QF-PCR assay, including two sex determination genes (AMXY and SRY), five X-linked short tandem repeats (STRs; DXS1053, DXS981, DXS6809, DXS1187, and DXS8377), one X/Y-common STR (X22), and two autosomal STRs (D13S305 and D21S11). Retrospective tests of 70 cases with known cytogenetic results indicated that the 10-plex QF-PCR assay could well determine sex chromosome copy numbers by both allelic peak numbers and a sex chromosome dosage calculation with the autosomal STRs as internal controls. Prospective comparison with cytogenetic karyotyping on 534 cases confirmed that the 10-plex QF-PCR assay could be well employed for sex chromosome aneuploidy diagnosis in at least the Chinese Han population. This is the first QF-PCR test for the diagnosis of sex chromosome aneuploidies in the Chinese population. This test is superior to previous designs by including up to 8 sex-linked markers covering different parts of sex chromosomes as well as employing internal controls for copy number dosage calculation in a single PCR reaction. Due to simple technique and data analysis, as well as easy implementation within routine clinical services, this method is of great clinical application value and could be widely applied. PMID:25207978

  14. Cytogenetic evaluation of human glial tumors: correlation of overexpression of epidermal growth factor receptor (EGFB) with abnormalities of chromosome 7

    SciTech Connect

    Bell, C.W.

    1987-01-01

    Chromosome banding analysis of human glial tumors were performed using G- and Q-banding techniques in an attempt to establish recurring sites of chromosome change. Results revealed a nonrandom karyotypic profile including aneuploidy and considerable variation in chromosome number (range 40 ..-->.. 200). All tumors examined displayed numerical abnormalities, with the most common numeric change being a gain of chromosome 7. An attempt was then made to correlate the observed chromosome 7 changes with activation of the cellular proto-oncogene c-erb-B, whose produce is the epidermal growth factor receptor (EGFR). Six human glial tumors were analyzed for /sup 125/I-EGF binding, EGFR gene copy number, EGFR gene rearrangement, mRNA expression, and karyotypic profile. Saturation analysis at 4/sup 0/C revealed significant numbers of EGFR's in all 6 tumors. Southern blotting analysis utilizing cDNA probes for the EGFR failed to demonstrate significant amplification or structural rearrangement of the EFGR gene. The results suggest that overexpression of the EGFR may be related to an alternative mechanism, other than gene amplification and elevated mRNA levels, such as the regulation of receptor biosynthesis and degradation. In summary, findings indicate that alterations of chromosome 7 are the most prevalent chromosomal change in human glial tumors, and that these alterations may lead to overexpression of the protooncogene c-erb-B.

  15. Sex chromosome differentiation in Humulus japonicus Siebold & Zuccarini, 1846 (Cannabaceae) revealed by fluorescence in situ hybridization of subtelomeric repeat

    PubMed Central

    Alexandrov, Oleg S.; Divashuk, Mikhail G.; Yakovin, Nikolay A.; Karlov, Gennady I.

    2012-01-01

    Abstract Humulus japonicus Siebold et Zucc (Japanese hop) is a dioecious species of the family Cannabaceae. The chromosome number is 2n = 16 = 14 + XX for females and 2n = 17 = 14 + XY1Y2 for male. To date, no fluorescence in situ hybridization (FISH) markers have been established for the identification of Humulus japonicus sex chromosomes. In this paper, we report a method for the mitotic and meiotic sex chromosome differentiation in Humulus japonicus by FISH for HJSR, a high copy subtelomeric repeat. The signal is present in the subtelomeric region of one arm of the X chromosome. We demonstrate that males have two Y chromosomes that differ in FISH signal with the HJSR probe. Indeed, the HJSR probe hybridizes to a subtelomeric region on both arms of chromosome Y1 but not of chromosome Y2. The orientation and position of pseudoautosomal regions (PAR1 and PAR2) were also determined. PMID:24260665

  16. Classical and Molecular Cytogenetics of Disorders of Sex Development in Domestic Animals

    Microsoft Academic Search

    D. A. F. Villagómez; P. Parma; O. Radi; G. Di Meo; A. Pinton; L. Iannuzzi; W. A. King

    2009-01-01

    The association of abnormal chromosome constitutions and disorders of sex development in domestic animals has been recorded since the beginnings of conventional cytogenetic analysis. Deviated karyotypes consisting of abnormal sex chromosome sets (e.g. aneuploidy) and\\/or the coexistence of cells with different sex chromosome constitutions (e.g. mosaicism or chimerism) in an individual seem to be the main causes of anomalies of

  17. Sex chromosomes and sex determination in reptiles William S Modi1

    E-print Network

    Crews, David

    used as a model system for reptilian physiology, neurology and reproductive behavior for many years [1 into reptilian genomics will unlock many of the fascinating secrets that nature has bundled into these intriguing animals. This review summarizes research on reptilian sex chromo- somes and sex determination

  18. Chromosome 17 abnormalities and TP53 mutations in adult soft tissue sarcomas.

    PubMed Central

    Latres, E.; Drobnjak, M.; Pollack, D.; Oliva, M. R.; Ramos, M.; Karpeh, M.; Woodruff, J. M.; Cordon-Cardo, C.

    1994-01-01

    This study was designed to determine the frequency of structural genetic abnormalities of chromosome 17 and the incidence of TP53 mutations as they relate to the biological behavior of adult soft tissue sarcomas. We analyzed a group of 73 soft tissue sarcomas of adults that were clinically and pathologically well characterized using molecular genetic techniques and expression studies. We then correlated genotype and phenotype with pathological parameters. Overall, allelic loss of 17p and 17q was identified in 53 and 29% of informative cases, respectively. p53 nuclear overexpression was detected in 34% of the tumors analyzed. We observed an association between 17p deletions and tumor presentation being more frequent in recurrent and metastatic tumors than primary lesion. p53 nuclear overexpression was associated with tumor grade, size, and more frequently detected in metastatic than primary sarcomas. The 11 intragenic mutations characterized included 10 cases of single base substitution and one single base deletion; 8 were of the missense type and 3 were nonsense. It is concluded that 17p deletions and TP53 mutations are common events in adult soft tissue sarcomas and that due to the trends observed with the cohort of patients analyzed they may become prognostic markers for patients affected with these tumors. Images Figure 2 Figure 3 PMID:8053493

  19. Graft-vs.-Host Disease: Role of Inflammation in the development of chromosomal abnormalities of keratinocytes

    PubMed Central

    Sloand, Elaine; Pfannes, Loretta; Ling, Casey; Jasek, Monika; Calado, Rodrigo; Tucker, Zachary C. G.; Feng, Xingmin; Hematti, Peiman; Maciejewski, Jaroslaw; Dunbar, Cynthia; Barrett, John; Young, Neal

    2012-01-01

    Graft-versus-host disease (GVHD) is a major risk factor for secondary malignancy after hematopoietic stem cell transplantation. Squamous cell carcinoma (SCC) of the skin and mucous membranes are especially frequent in this setting where aneuploidy and tetraploidy are associated with aggressive disease. The current study is directed to the mechanism of neoplasia in this setting. Un-manipulated keratinocytes from areas of oral GVHD in 9 patients showed tetraploidy in 10–46% of cells when examined by florescence in situ hybridization (FISH). Keratinocytes isolated from biopsy sites of GVHD but not from normal tissue showed even greater numbers of tetraploid cells (mean 78%, range 15–85%; N=9) after culture. To mimic the inflammatory process in GVHD, allogeneic HLA- mismatched lymphocytes were mixed with normal keratinocytes. After two weeks, substantial numbers of aneuploid and tetraploid cells were evident in cultures with lymphocytes and with purified CD8 but not CD4 cells. Telomere length was substantially decreased in the lymphocyte-treated sample. No mutations were present in p53 gene, although haploinsufficiency for p53 due to loss of chromosome 17 was common in cells exposed to lymphocytes. These findings suggest that in GVHD, inflammation and repeated cell division correlates with the development of karyotypic abnormalities. PMID:20659573

  20. Rainfall-driven sex-ratio genes in African buffalo suggested by correlations between Y-chromosomal haplotype frequencies and foetal sex ratio

    PubMed Central

    2010-01-01

    Background The Y-chromosomal diversity in the African buffalo (Syncerus caffer) population of Kruger National Park (KNP) is characterized by rainfall-driven haplotype frequency shifts between year cohorts. Stable Y-chromosomal polymorphism is difficult to reconcile with haplotype frequency variations without assuming frequency-dependent selection or specific interactions in the population dynamics of X- and Y-chromosomal genes, since otherwise the fittest haplotype would inevitably sweep to fixation. Stable Y-chromosomal polymorphism due one of these factors only seems possible when there are Y-chromosomal distorters of an equal sex ratio, which act by negatively affecting X-gametes, or Y-chromosomal suppressors of a female-biased sex ratio. These sex-ratio (SR) genes modify (suppress) gamete transmission in their own favour at a fitness cost, allowing for stable polymorphism. Results Here we show temporal correlations between Y-chromosomal haplotype frequencies and foetal sex ratios in the KNP buffalo population, suggesting SR genes. Frequencies varied by a factor of five; too high to be alternatively explained by Y-chromosomal effects on pregnancy loss. Sex ratios were male-biased during wet and female-biased during dry periods (male proportion: 0.47-0.53), seasonally and annually. Both wet and dry periods were associated with a specific haplotype indicating a SR distorter and SR suppressor, respectively. Conclusions The distinctive properties suggested for explaining Y-chromosomal polymorphism in African buffalo may not be restricted to this species alone. SR genes may play a broader and largely overlooked role in mammalian sex-ratio variation. PMID:20416038

  1. The XX Sex Chromosome Complement in Mice is Associated with Increased Spontaneous Lupus as compared to XY

    PubMed Central

    Sasidhar, Manda V.; Itoh, Noriko; Gold, Stefan M.; Lawson, Gregory W.; Voskuhl, Rhonda R.

    2015-01-01

    Objectives Many autoimmune diseases are characterized by a female predominance. This may be caused by sex hormones, sex chromosomes or both. Here, we use a transgenic mouse model to investigate how sex chromosome complement, not confounded by differences in gonadal type, might contribute to lupus pathogenesis. Methods Transgenic NZM2328 mice were created by deletion of the Sry gene from the Y chromosome, thereby separating genetic from gonadal sex. We compared survival, renal histopathology, and markers of immune activation in mice carrying the XX versus the XY- sex chromosome complement, with each genotype being ovary bearing. Results Mice with XX sex chromosome complement as compared with XY- exhibited poorer survival rates and increased kidney pathology. Splenic T lymphocytes from XX mice demonstrated upregulated X-linked CD40Ligand expression and higher levels of activation markers ex vivo. We found increased MMPs, TGF? and IL13 production, while IL2 was lower in XX mice. Finally, we observed an accumulation of splenic follicular B cells and peritoneal marginal zone B cells, coupled with upregulated costimulatory marker expression on B cells in the XX mice. Conclusion Together, these data show that the XX sex chromosome complement, as compared to XY-, is with associated accelerated spontaneous lupus. PMID:22580585

  2. Rapid and early determination of sex using trophoblast biopsy specimens and Y chromosome specific DNA probes.

    PubMed Central

    Vergnaud, G; Kaplan, L; Weissenbach, J; Dumez, Y; Berger, R; Tiollais, P; Guellaen, G

    1984-01-01

    The feasibility of determining sex by analysing deoxyribonucleic acid (DNA) with two probes specific for Y chromosomes was shown using DNA obtained from samples of blood from 30 non-related males and females of different ethnic origin. The DNA was spotted on nitrocellulose filters and hybridised with both a repetitive (P1) and a unique (49f) sequence specific for the human Y chromosome. A strong positive signal with both probes indicated the presence of male DNA. The sex of 12 fetuses was then similarly determined by molecular characterisation of DNA from trophoblast biopsy specimens. Chorionic samples were obtained in seven cases before termination of pregnancy in the first trimester and the aborted embryos subjected to karyotyping and sex chromatin analysis. In the five other cases samples were obtained from placentas obtained during caesarean section. Results of hybridisation were compared with those from cytogenic studies and actual sex at birth. The sex of all 12 fetuses was determined correctly by hybridisation. Images FIG 1 FIG 2 FIG 3 PMID:6428684

  3. An Autosomal Gene That Affects X Chromosome Expression and Sex Determination in CAENORHABDITIS ELEGANS

    PubMed Central

    Meneely, Philip M.; Wood, William B.

    1984-01-01

    Recessive mutant alleles at the autosomal dpy-21 locus of C. elegans cause a dumpy phenotype in XX animals but not in XO animals. This dumpy phenotype is characteristic of X chromosome aneuploids with higher than normal X to autosome ratios and is proposed to result from overexpression of X-linked genes. We have isolated a new dpy-21 allele that also causes partial hermaphroditization of XO males, without causing the dumpy phenotype. All dpy-21 alleles show hermaphroditization effects in XO males that carry a duplication of part of the X chromosome and also partially suppress a transformer (tra-1) mutation that converts XX animals into males. Experiments with a set of X chromosome duplications show that the defects of dpy-21 mutants can result from interaction with several different regions of the X chromosome. We propose that dpy-21 regulates X chromosome expression and may be involved in interpreting X chromosome dose for the developmental decisions of both sex determination and dosage compensation. PMID:6537930

  4. Sex Chromosome Mosaicism and Hybrid Speciation among Tiger Swallowtail Butterflies

    PubMed Central

    Kunte, Krushnamegh; Shea, Cristina; Aardema, Matthew L.; Scriber, J. Mark; Juenger, Thomas E.; Gilbert, Lawrence E.; Kronforst, Marcus R.

    2011-01-01

    Hybrid speciation, or the formation of a daughter species due to interbreeding between two parental species, is a potentially important means of diversification, because it generates new forms from existing variation. However, factors responsible for the origin and maintenance of hybrid species are largely unknown. Here we show that the North American butterfly Papilio appalachiensis is a hybrid species, with genomic admixture from Papilio glaucus and Papilio canadensis. Papilio appalachiensis has a mosaic phenotype, which is hypothesized to be the result of combining sex-linked traits from P. glaucus and P. canadensis. We show that P. appalachiensis' Z-linked genes associated with a cooler thermal habitat were inherited from P. canadensis, whereas its W-linked mimicry and mitochondrial DNA were inherited from P. glaucus. Furthermore, genome-wide AFLP markers showed nearly equal contributions from each parental species in the origin of P. appalachiensis, indicating that it formed from a burst of hybridization between the parental species, with little subsequent backcrossing. However, analyses of genetic differentiation, clustering, and polymorphism based on molecular data also showed that P. appalachiensis is genetically distinct from both parental species. Population genetic simulations revealed P. appalachiensis to be much younger than the parental species, with unidirectional gene flow from P. glaucus and P. canadensis into P. appalachiensis. Finally, phylogenetic analyses, combined with ancestral state reconstruction, showed that the two traits that define P. appalachiensis' mosaic phenotype, obligatory pupal diapause and mimicry, evolved uniquely in P. canadensis and P. glaucus, respectively, and were then recombined through hybridization to form P. appalachiensis. These results suggest that natural selection and sex-linked traits may have played an important role in the origin and maintenance of P. appalachiensis as a hybrid species. In particular, ecological barriers associated with a steep thermal cline appear to maintain the distinct, mosaic genome of P. appalachiensis despite contact and occasional hybridization with both parental species. PMID:21931567

  5. Sex chromosome mosaicism and hybrid speciation among tiger swallowtail butterflies.

    PubMed

    Kunte, Krushnamegh; Shea, Cristina; Aardema, Matthew L; Scriber, J Mark; Juenger, Thomas E; Gilbert, Lawrence E; Kronforst, Marcus R

    2011-09-01

    Hybrid speciation, or the formation of a daughter species due to interbreeding between two parental species, is a potentially important means of diversification, because it generates new forms from existing variation. However, factors responsible for the origin and maintenance of hybrid species are largely unknown. Here we show that the North American butterfly Papilio appalachiensis is a hybrid species, with genomic admixture from Papilio glaucus and Papilio canadensis. Papilio appalachiensis has a mosaic phenotype, which is hypothesized to be the result of combining sex-linked traits from P. glaucus and P. canadensis. We show that P. appalachiensis' Z-linked genes associated with a cooler thermal habitat were inherited from P. canadensis, whereas its W-linked mimicry and mitochondrial DNA were inherited from P. glaucus. Furthermore, genome-wide AFLP markers showed nearly equal contributions from each parental species in the origin of P. appalachiensis, indicating that it formed from a burst of hybridization between the parental species, with little subsequent backcrossing. However, analyses of genetic differentiation, clustering, and polymorphism based on molecular data also showed that P. appalachiensis is genetically distinct from both parental species. Population genetic simulations revealed P. appalachiensis to be much younger than the parental species, with unidirectional gene flow from P. glaucus and P. canadensis into P. appalachiensis. Finally, phylogenetic analyses, combined with ancestral state reconstruction, showed that the two traits that define P. appalachiensis' mosaic phenotype, obligatory pupal diapause and mimicry, evolved uniquely in P. canadensis and P. glaucus, respectively, and were then recombined through hybridization to form P. appalachiensis. These results suggest that natural selection and sex-linked traits may have played an important role in the origin and maintenance of P. appalachiensis as a hybrid species. In particular, ecological barriers associated with a steep thermal cline appear to maintain the distinct, mosaic genome of P. appalachiensis despite contact and occasional hybridization with both parental species. PMID:21931567

  6. Automated identification of abnormal metaphase chromosome cells for the detection of chronic myeloid leukemia using microscopic images

    NASA Astrophysics Data System (ADS)

    Wang, Xingwei; Zheng, Bin; Li, Shibo; Mulvihill, John J.; Chen, Xiaodong; Liu, Hong

    2010-07-01

    Karyotyping is an important process to classify chromosomes into standard classes and the results are routinely used by the clinicians to diagnose cancers and genetic diseases. However, visual karyotyping using microscopic images is time-consuming and tedious, which reduces the diagnostic efficiency and accuracy. Although many efforts have been made to develop computerized schemes for automated karyotyping, no schemes can get be performed without substantial human intervention. Instead of developing a method to classify all chromosome classes, we develop an automatic scheme to detect abnormal metaphase cells by identifying a specific class of chromosomes (class 22) and prescreen for suspicious chronic myeloid leukemia (CML). The scheme includes three steps: (1) iteratively segment randomly distributed individual chromosomes, (2) process segmented chromosomes and compute image features to identify the candidates, and (3) apply an adaptive matching template to identify chromosomes of class 22. An image data set of 451 metaphase cells extracted from bone marrow specimens of 30 positive and 30 negative cases for CML is selected to test the scheme's performance. The overall case-based classification accuracy is 93.3% (100% sensitivity and 86.7% specificity). The results demonstrate the feasibility of applying an automated scheme to detect or prescreen the suspicious cancer cases.

  7. Automated identification of abnormal metaphase chromosome cells for the detection of chronic myeloid leukemia using microscopic images

    PubMed Central

    Wang, Xingwei; Zheng, Bin; Li, Shibo; Mulvihill, John J.; Chen, Xiaodong; Liu, Hong

    2010-01-01

    Karyotyping is an important process to classify chromosomes into standard classes and the results are routinely used by the clinicians to diagnose cancers and genetic diseases. However, visual karyotyping using microscopic images is time-consuming and tedious, which reduces the diagnostic efficiency and accuracy. Although many efforts have been made to develop computerized schemes for automated karyotyping, no schemes can get be performed without substantial human intervention. Instead of developing a method to classify all chromosome classes, we develop an automatic scheme to detect abnormal metaphase cells by identifying a specific class of chromosomes (class 22) and prescreen for suspicious chronic myeloid leukemia (CML). The scheme includes three steps: (1) iteratively segment randomly distributed individual chromosomes, (2) process segmented chromosomes and compute image features to identify the candidates, and (3) apply an adaptive matching template to identify chromosomes of class 22. An image data set of 451 metaphase cells extracted from bone marrow specimens of 30 positive and 30 negative cases for CML is selected to test the scheme’s performance. The overall case-based classification accuracy is 93.3% (100% sensitivity and 86.7% specificity). The results demonstrate the feasibility of applying an automated scheme to detect or prescreen the suspicious cancer cases. PMID:20799828

  8. Survey of repetitive sequences in Silene latifolia with respect to their distribution on sex chromosomes

    Microsoft Academic Search

    Tomas Cermak; Zdenek Kubat; Roman Hobza; Andrea Koblizkova; Alex Widmer; Jiri Macas; Boris Vyskot; Eduard Kejnovsky

    2008-01-01

    We carried out a global survey of all major types of transposable elements in Silene latifolia, a model species with sex chromosomes that are in the early stages of their evolution. A shotgun genomic library was screened\\u000a with genomic DNA to isolate and characterize the most abundant elements. We found that the most common types of elements were\\u000a the subtelomeric

  9. Brief Report: Association of Sex Chromosome Anomalies With Childhood-Onset Psychotic Disorders

    Microsoft Academic Search

    SANJIV KUMRA; EDYTHE WIGGS; DONNA KRASNEWICH; JEANNE MECK; ANN C. M. SMITH; JEFFREY BEDWELL; THOMAS FERNANDEZ; LESLIE K. JACOBSEN; MARGE LENANE; JUDITH L. RAPOPORT

    1998-01-01

    ObjectiveAn apparent excess of sex chromosome aneuploidies (XXY, XXX, and possibly XYY) has been reported in patients with adult-onset schizophrenia and with unspecified psychoses. This study describes the results of cytogenetic screening carried out for pediatric patients meeting DSM-III-R criteria for childhood-onset schizophrenia (COS) and a subgroup of patients with childhood-onset psychotic disorder not otherwise specified, provisionally labeled by the

  10. Sex chromosome trisomies in Europe: prevalence, prenatal detection and outcome of pregnancy

    Microsoft Academic Search

    Patricia Anne Boyd; Maria Loane; Ester Garne; Babak Khoshnood; Helen Dolk; PA Boyd

    2011-01-01

    This study aims to assess prevalence and pregnancy outcome for sex chromosome trisomies (SCTs) diagnosed prenatally or in the first year of life. Data held by the European Surveillance of Congenital Anomalies (EUROCAT) database on SCT cases delivered 2000–2005 from 19 population-based registries in 11 European countries covering 2.5 million births were analysed. Cases included were livebirths diagnosed to 1

  11. Probing the W chromosome of the codling moth, Cydia pomonella , with sequences from microdissected sex chromatin

    Microsoft Academic Search

    Iva Fuková; Walther Traut; Magda Vítková; Petr Nguyen; Svatava Kubí?ková; František Marec

    2007-01-01

    The W chromosome of the codling moth, Cydia pomonella, like that of most Lepidoptera species, is heterochromatic and forms a female-specific sex chromatin body in somatic cells.\\u000a We collected chromatin samples by laser microdissection from euchromatin and W-chromatin bodies. DNA from the samples was\\u000a amplified by degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) and used to prepare painting probes and\\u000a start

  12. Cytogenetic and molecular analysis of the multiple sex chromosome system of Rumex acetosa

    Microsoft Academic Search

    C Ruiz Rejón; M Jamilena; M Garrido Ramos; J S Parker; M Ruiz Rejón

    1994-01-01

    A repeated sequence of 180 bp in tandem array has been isolated from the dioecious plant species Rumex acetosa which has a multiple sex chromosome system, XX?\\/XY1Y2?. There are two or three thin C-bands on the X while the Ys are almost entirely heteropycnotic and DAPI-positive but contain no C-band material. The Ys thus represent massive blocks of facultative heterochromatin.

  13. X and Y chromosome behavior in brain tumors: Pieces in a puzzle

    SciTech Connect

    Hecht, B.K. [Hecht Associates, Jacksonville, FL (United States); Chatel, M; Gioanni, J. [Univ. of Nice (France)] [and others

    1994-09-01

    Sex chromosome behavior in selected somatic cells is baffling. We serendipitously encountered this sex chromosome shuffle while studying malignant gliomas. Tumor specimens from 3/10 (30%) females and 15/27 (56%) males had sex chromosome abnormalities. Specimens from females showed X loss in 2 cases and possible X gain in 1 case. In 2 cases with autosomal abnormalities, only XX cells were found, suggesting that sex chromosome changes are independent of autosomal changes. Specimens from males showed Y rearrangements in 3 cases, Y loss in 15 cases, XX in 3 cases and autosomal abnormalities in 9 cases. The Y rearrangements may provide a route to Y loss whereas the advent of XX clones in male tumors bespeaks X isodisomy, a mechanism for adding an extra active X. The autosomal changes were rearrangements against a pseudo-diploid background in 5 cases and near-triploidy/tetraploidy in 4 cases. The cases with autosomal changes tended not to have sex chromosome abnormalities (p<0.01) and, the converse, cases with sex chromosome anomalies were without autosomal abnormalities (p<0.05). The process of sex chromosome changes appears independent of the process of autosomal changes. The conventional interpretation: the sex chromosome changes in brain tumors are in non-malignant cells. An unconventional interpretation: sex chromosome changes represent an alternative avenue to malignancy.

  14. Multiple marker screening test: identification of fetal cystic hygroma, hydrops, and sex chromosome aneuploidy.

    PubMed

    Wenstrom, K D; Boots, L R; Cosper, P C

    1996-01-01

    The goal of this study was to determine if the multiple marker screening test (maternal serum alpha-fetoprotein, unconjugated estriol, human chorionic gonadotrophin, and maternal age) detects fetal Turner syndrome or just cystic hygroma/hydrops. Multiple marker screening tests from 4 groups were compared: 1) Turner syndrome with hydrops/ hygroma group (n = 10) = fetuses with cystic hygroma/hydrops and a 45X karyotype, 2) Turner syndrome without hydrops/hygroma (n = 9) = sonographically unremarkable fetal Turner syndrome or Turner mosaic, 3) hydrops group (n = 8) = all cases of fetal cystic hygroma/hydrops excluding Turner syndrome, 4) sex chromosome aneuploidy group (n = 16) = other sonographically normal fetal sex chromosome aneuploidies. Positive screening tests (Down syndrome risk > or = 1:190 or MSAFP > or = 2.5 MOM) were found in 60% (6/10) of the Turner syndrome with hydrops/hygroma group, but only 11% (1/9) of the Turner syndrome without hydrops/hygroma group (P = .04). The incidence of positive screening tests in the Hydrops group was 75% (6/8), while it was only 12.5% (2/16) in the other sex chromosome aneuploidy group. We conclude that the multiple marker screening test identifies fetuses with cystic hygroma/hydrops, and may do so independently of the etiology of the hydrops. PMID:8796763

  15. SNP-based non-invasive prenatal testing detects sex chromosome aneuploidies with high accuracy

    PubMed Central

    Samango-Sprouse, Carole; Banjevic, Milena; Ryan, Allison; Sigurjonsson, Styrmir; Zimmermann, Bernhard; Hill, Matthew; Hall, Megan P.; Westemeyer, Margaret; Saucier, Jennifer; Demko, Zachary; Rabinowitz, Matthew

    2013-01-01

    Objective To develop a single nucleotide polymorphism- and informatics-based non-invasive prenatal test that detects sex chromosome aneuploidies early in pregnancy. Methods Fifteen aneuploid samples, including thirteen 45,X, two 47,XXY, and one 47,XYY, along with 185 euploid controls, were analyzed. Cell-free DNA was isolated from maternal plasma, amplified in a single multiplex PCR assay that targeted 19,488 polymorphic loci covering chromosomes 13, 18, 21, X, and Y, and sequenced. Sequencing results were analyzed using a Bayesian-based maximum likelihood statistical method to determine copy number of interrogated chromosomes, calculating sample-specific accuracies. Results Of the samples that passed a stringent quality control metric (93%), the algorithm correctly identified copy number at all five chromosomes in all 187 samples, for 934/935 correct calls as early as 9.4 weeks of gestation. We detected 45,X with 91.7% sensitivity (CI: 61.5-99.8%) and 100% specificity (CI: 97.9-100%), and 47,XXY and 47,XYY. The average calculated accuracy was 99.78%. Conclusion This method non-invasively detected 45,X, 47,XXY, and 47,XYY fetuses from cfDNA isolated from maternal plasma with high calculated accuracies, and thus offers a non-invasive method with the potential to function as a routine screen allowing for early prenatal detection of rarely diagnosed yet commonly occurring sex aneuploidies. PMID:23712453

  16. Mapping the stability of human brain asymmetry across five sex-chromosome aneuploidies.

    PubMed

    Lin, Amy; Clasen, Liv; Lee, Nancy Raitano; Wallace, Gregory L; Lalonde, Francois; Blumenthal, Jonathan; Giedd, Jay N; Raznahan, Armin

    2015-01-01

    The human brain displays stereotyped and early emerging patterns of cortical asymmetry in health. It is unclear if these asymmetries are highly sensitive to genetic and environmental variation or fundamental features of the brain that can survive severe developmental perturbations. To address this question, we mapped cortical thickness (CT) asymmetry in a group of genetically defined disorders known to impact CT development. Participants included 137 youth with one of five sex-chromosome aneuploidies [SCAs; XXX (n = 28), XXY (n = 58), XYY (n = 26), XXYY (n = 20), and XXXXY (n = 5)], and 169 age-matched typically developing controls (80 female). In controls, we replicated previously reported rightward inferior frontal and leftward lateral parietal CT asymmetry. These opposing frontoparietal CT asymmetries were broadly preserved in all five SCA groups. However, we also detected foci of shifting CT asymmetry with aneuploidy, which fell almost exclusively within regions of significant CT asymmetry in controls. Specifically, X-chromosome aneuploidy accentuated normative rightward inferior frontal asymmetries, while Y-chromosome aneuploidy reversed normative rightward medial prefrontal and lateral temporal asymmetries. These findings indicate that (1) the stereotyped normative pattern of opposing frontoparietal CT asymmetry arises from developmental mechanisms that can withstand gross chromosomal aneuploidy and (2) X and Y chromosomes can exert focal, nonoverlapping and directionally opposed influences on CT asymmetry within cortical regions of significant asymmetry in health. Our study attests to the resilience of developmental mechanisms that support the global patterning of CT asymmetry in humans, and motivates future research into the molecular bases and functional consequences of sex chromosome dosage effects on CT asymmetry. PMID:25568109

  17. Sex chromosome conservation, DMRT1 phylogeny and gonad morphology in diploid Palearctic green toads (Bufo viridis subgroup).

    PubMed

    Tamschick, Stephanie; Rozenblut-Ko?cisty, Beata; Bonato, Lucio; Dufresnes, Christophe; Lymberakis, Petros; Kloas, Werner; Ogielska, Maria; Stöck, Matthias

    2014-01-01

    Due to the prevailing sex chromosome homomorphy and large genome size, the knowledge on sex determination systems, sex chromosomes and sex-determining genes in amphibians remains scarce. Using 3 cross-amplifying sex-linked microsatellite markers, we uncover sex determination systems and sex chromosomes in purebred, diploid Palearctic green toads (Bufo viridis subgroup), which had so far only been characterized in laboratory-bred hybrids. Our data support an XY system in B. balearicus, B. viridis and B. variabilis. While females show recombination, it is strongly suppressed (or not detectable) in males. Markers corroborate the largest chromosome pair 1 (homologous to linkage group 1 of Xenopus tropicalis) to represent the sex chromosomes in diploid species of the B. viridis subgroup (B. siculus, B. shaartusiensis, B. balearicus, B. turanensis, B. variabilis, B. viridis, and probably B. boulengeri). This chromosome harbors DMRT1, a key gene of the sexual pathway in deeply divergent animal taxa. However, our phylogenetic analysis of a 600-bp fragment of that gene in diploid green toad taxa reveals that X and Y alleles cluster by species and not by gametolog. This suggests that XY-sequence similarity stems from occasional XY recombination within DMRT1, and we preliminarily reject its role as the master sex determination gene, pending future extension of this evidence to the entire DMRT1 gene. We further create a chain of evidence, which supports the hypothesis that linkage group 1 of X. tropicalis appears to be maintained as the largest chromosome (1), and thus is homologous in anuran karyotype evolution from pipid to hylid, bufonid and ranid anurans. PMID:25823515

  18. SASS6 overexpression is associated with mitotic chromosomal abnormalities and a poor prognosis in patients with colorectal cancer.

    PubMed

    Shinmura, Kazuya; Kato, Hisami; Kawanishi, Yuichi; Nagura, Kiyoko; Kamo, Takaharu; Okubo, Yusuke; Inoue, Yusuke; Kurabe, Nobuya; Du, Chunping; Iwaizumi, Moriya; Kurachi, Kiyotaka; Nakamura, Toshio; Sugimura, Haruhiko

    2015-08-01

    Spindle assembly abnormal protein 6 homolog (SASS6) plays an important role in the regulation of centriole duplication. To date, the genetic alteration of SASS6 has not been reported in human cancers. In the present study, we examined whether SASS6 expression is abnormally regulated in colorectal cancers (CRCs). Increased SASS6 mRNA and protein expression levels were observed in 49 (60.5%) of the 81 primary CRCs and 11 (57.9%) of the 19 primary CRCs, respectively. Moreover, the upregulation of SASS6 mRNA expression was statistically significant (P=0.0410). Next, using DLD-1 colon cancer cells inducibly expressing SASS6, SASS6 overexpression was shown to induce centrosome amplification, mitotic abnormalities such as chromosomal misalignment and lagging chromosome, and chromosomal numerical changes. Furthermore, SASS6 overexpression was associated with anaphase bridge formation, a type of mitotic structural abnormality, in primary CRCs (P<0.01). SASS6 upregulation in colon cancer was also revealed in the Cancer Genome Atlas (TCGA) data and was shown to be an independent predictor of poor survival (multivariate analysis: hazard ratio, 2.805; 95% confidence interval, 1.244?7.512; P=0.0112). Finally, further analysis of the TCGA data demonstrated SASS6 upregulation in a modest manner in 8 of 11 cancer types other than colon cancer, and SASS6 upregulation was found to be associated with a poor survival outcome in patients with kidney renal cell carcinoma and lung adenocarcinoma. Our present findings revealed that the upregulation of SASS6 expression is involved in the pathogenesis of CRC and is associated with a poor prognosis among patients with colon cancer. They also suggest that SASS6 upregulation is a genetic abnormality relatively common in human cancer. PMID:26035073

  19. Molecular cytogenetic characterization of Rumex papillaris, a dioecious plant with an XX/XY(1)Y (2) sex chromosome system.

    PubMed

    Navajas-Pérez, Rafael; Schwarzacher, Trude; Rejón, Manuel Ruiz; Garrido-Ramos, Manuel A

    2009-01-01

    Rumex papillaris Boiss, & Reut., an Iberian endemic, belongs to the section Acetosa of the genus Rumex whose main representative is R. acetosa L., a species intensively studied in relation to sex-chromosome evolution. Here, we characterize cytogenetically the chromosomal complement of R. papillaris in an effort to enhance future comparative genomic approaches and to better our understanding of sex chromosome structure in plants. Rumex papillaris, as is common in this group, is a dioecious species characterized by the presence of a multiple sex chromosome system (with females 2n = 12 + XX and males 2n = 12 + XY(1)Y(2)). Except for the X chromosome both Y chromosomes are the longest in the karyotype and appear heterochromatic due to the accumulation of at least two satellite DNA families, RAE180 and RAYSI. Each chromosome of pair VI has an additional major heterochromatin block at the distal region of the short arm. These supernumerary heterochromatic blocks are occupied by RAE730 satellite DNA family. The Y-related RAE180 family is also present in an additional minor autosomal locus. Our comparative study of the chromosomal organization of the different satellite-DNA sequences in XX/XY and XX/XY(1)Y(2) Rumex species demonstrates that of active mechanisms of heterochromatin amplification occurred and were accompanied by chromosomal rearrangements giving rise to the multiple XX/XY(1)Y(2) chromosome systems observed in Rumex. Additionally, Y(1) and Y(2) chromosomes have undergone further rearrangements leading to differential patterns of Y-heterochromatin distribution between Rumex species with multiple sex chromosome systems. PMID:18373205

  20. [Prenatal diagnosis for chromosomal abnormality: time to change the Israeli policy].

    PubMed

    Falik-Zaccai, Tzipora; Golan, Natali; Cuckle, Howard

    2006-12-01

    Down syndrome is the most common serious chromosomal abnormality among live births. Safe, inexpensive, and accurate prenatal screening, with a high detection rate (DR) and low false positive rate (FPR) is needed for prevention. Second trimester screening, based on three maternal serum markers (free betaHCG, uE3, AFP) has a 59-75% DR with a 5% FPR. The addition of Inhibin-A to this panel (Quadruple test), increases DR to 70-85%. First trimester screening combining two serum markers (free betaHCG, PAPP-A), with ultrasound nuchal translucency (NT) has a 80-90% DR, allows reassurance or early diagnosis and pregnancy termination in a relatively simple and safe technique. Testing sequentially in both trimesters (NT, PAPP-A, then Quadruple markers), but withholding results until all markers are measured, allows a 92-94% DR with a low FPR, although the clinical and human advantages of early testing are lost. Three alternative approaches are presented in this review, which achieve a high DR and low FPR without this disadvantage. Based on recently published data, we propose a change in the current policy practiced in Israel whereby women above 35 are referred for invasive prenatal diagnosis paid by the government. Instead, awareness of modern screening methods should be enhanced and invasive diagnosis only offered to women whose risk based on screening exceeds an agreed cutoff. This would achieve better and safer prevention acceptable to a wide spectrum of ethnicities, religions and cultures in Israeli society, at a reasonable cost to the public health system in Israel. PMID:17220033

  1. Horse domestication and conservation genetics of Przewalski's horse inferred from sex chromosomal and autosomal sequences.

    PubMed

    Lau, Allison N; Peng, Lei; Goto, Hiroki; Chemnick, Leona; Ryder, Oliver A; Makova, Kateryna D

    2009-01-01

    Despite their ability to interbreed and produce fertile offspring, there is continued disagreement about the genetic relationship of the domestic horse (Equus caballus) to its endangered wild relative, Przewalski's horse (Equus przewalskii). Analyses have differed as to whether or not Przewalski's horse is placed phylogenetically as a separate sister group to domestic horses. Because Przewalski's horse and domestic horse are so closely related, genetic data can also be used to infer domestication-specific differences between the two. To investigate the genetic relationship of Przewalski's horse to the domestic horse and to address whether evolution of the domestic horse is driven by males or females, five homologous introns (a total of approximately 3 kb) were sequenced on the X and Y chromosomes in two Przewalski's horses and three breeds of domestic horses: Arabian horse, Mongolian domestic horse, and Dartmoor pony. Five autosomal introns (a total of approximately 6 kb) were sequenced for these horses as well. The sequences of sex chromosomal and autosomal introns were used to determine nucleotide diversity and the forces driving evolution in these species. As a result, X chromosomal and autosomal data do not place Przewalski's horses in a separate clade within phylogenetic trees for horses, suggesting a close relationship between domestic and Przewalski's horses. It was also found that there was a lack of nucleotide diversity on the Y chromosome and higher nucleotide diversity than expected on the X chromosome in domestic horses as compared with the Y chromosome and autosomes. This supports the hypothesis that very few male horses along with numerous female horses founded the various domestic horse breeds. Patterns of nucleotide diversity among different types of chromosomes were distinct for Przewalski's in contrast to domestic horses, supporting unique evolutionary histories of the two species. PMID:18931383

  2. Congenital Abnormalities

    MedlinePLUS

    ... and may develop serious health problems (e.g. Down syndrome ). Single-Gene Abnormalities Sometimes the chromosomes are normal ... Detecting Genetic Abnormalities Prenatal Genetic Counseling Children with Down Syndrome: Health Care Information for Families Last Updated 5/ ...

  3. Sex preselection in mammals. Separation of sperm bearing Y and O chromosomes in the vole Microtus oregoni

    SciTech Connect

    Pinkel, D.; Gledhill, B.L.; Lake, S.; Stephenson, D.; Van Dilla, M.A.

    1982-11-26

    The two sex determining sperm populations of the vole Microtus oregoni were separated according to DNA content by use of flow sorting instrumentation. Although the sperm were not viable, they should be useful for addressing the question of haploid expression of genes linked to sex chromosomes and for efficiently searching for biochemical markers that differentiate the two populations.

  4. Survey of repetitive sequences in Silene latifolia with respect to their distribution on sex chromosomes.

    PubMed

    Cermak, Tomas; Kubat, Zdenek; Hobza, Roman; Koblizkova, Andrea; Widmer, Alex; Macas, Jiri; Vyskot, Boris; Kejnovsky, Eduard

    2008-01-01

    We carried out a global survey of all major types of transposable elements in Silene latifolia, a model species with sex chromosomes that are in the early stages of their evolution. A shotgun genomic library was screened with genomic DNA to isolate and characterize the most abundant elements. We found that the most common types of elements were the subtelomeric tandem repeat X-43.1 and Gypsy retrotransposons, followed by Copia retrotransposons and LINE non-LTR elements. SINE elements and DNA transposons were less abundant. We also amplified transposable elements with degenerate primers and used them to screen the library. The localization of elements by FISH revealed that most of the Copia elements were accumulated on the Y chromosome. Surprisingly, one type of Gypsy element, which was similar to Ogre elements known from legumes, was almost absent on the Y chromosome but otherwise uniformly distributed on all chromosomes. Other types of elements were ubiquitous on all chromosomes. Moreover, we isolated and characterized two new tandem repeats. One of them, STAR-C, was localized at the centromeres of all chromosomes except the Y chromosome, where it was present on the p-arm. Its variant, STAR-Y, carrying a small deletion, was specifically localized on the q-arm of the Y chromosome. The second tandem repeat, TR1, co-localized with the 45S rDNA cluster in the subtelomeres of five pairs of autosomes. FISH analysis of other Silene species revealed that some elements (e.g., Ogre-like elements) are confined to the section Elisanthe while others (e.g. Copia or Athila-like elements) are present also in more distant species. Similarly, the centromeric satellite STAR-C was conserved in the genus Silene whereas the subtelomeric satellite X-43.1 was specific for Elisanthe section. Altogether, our data provide an overview of the repetitive sequences in Silene latifolia and revealed that genomic distribution and evolutionary dynamics differ among various repetitive elements. The unique pattern of repeat distribution is found on the Y chromosome, where some elements are accumulated while other elements are conspicuously absent, which probably reflects different forces shaping the Y chromosome. PMID:18853265

  5. Chromosomal Position Effects Reveal Different cis-Acting Requirements for rDNA Transcription and Sex Chromosome Pairing in Drosophila melanogaster

    Microsoft Academic Search

    Albert Briscoe; John E. Tomkiel

    In Drosophila melanogaster, the rDNA loci function in ribosome biogenesis and nucleolar formation and also as sex chromosome pairing sites in male meiosis. These activities are not dependent on the heterochromatic location of the rDNA, because euchromatic transgenes are competent to form nucleoli and restore pairing to rDNA-deficient X chromosomes. These transgene studies, however, do not address requirements for the

  6. Microsatellite distribution on sex chromosomes at different stages of heteromorphism and heterochromatinization in two lizard species (Squamata: Eublepharidae: Coleonyx elegans and Lacertidae: Eremias velox)

    PubMed Central

    2011-01-01

    Background The accumulation of repetitive sequences such as microsatellites during the differentiation of sex chromosomes has not been studied in most squamate reptiles (lizards, amphisbaenians and snakes), a group which has a large diversity of sex determining systems. It is known that the Bkm repeats containing tandem arrays of GATA tetranucleotides are highly accumulated on the degenerated W chromosomes in advanced snakes. Similar, potentially homologous, repetitive sequences were found on sex chromosomes in other vertebrates. Using FISH with probes containing all possible mono-, di-, and tri-nucleotide sequences and GATA, we studied the genome distribution of microsatellite repeats on sex chromosomes in two lizard species (the gecko Coleonyx elegans and the lacertid Eremias velox) with independently evolved sex chromosomes. The gecko possesses heteromorphic euchromatic sex chromosomes, while sex chromosomes in the lacertid are homomorphic and the W chromosome is highly heterochromatic. Our aim was to test whether microsatellite distribution on sex chromosomes corresponds to the stage of their heteromorphism or heterochromatinization. Moreover, because the lizards lie phylogenetically between snakes and other vertebrates with the Bkm-related repeats on sex chromosomes, the knowledge of their repetitive sequence is informative for the determination of conserved versus convergently evolved repetitive sequences across vertebrate lineages. Results Heteromorphic sex chromosomes of C. elegans do not show any sign of microsatellite accumulation. On the other hand, in E. velox, certain microsatellite sequences are extensively accumulated over the whole length or parts of the W chromosome, while others, including GATA, are absent on this heterochromatinized sex chromosome. Conclusion The accumulation of microsatellite repeats corresponds to the stage of heterochromatinization of sex chromosomes rather than to their heteromorphism. The lack of GATA repeats on the sex chromosomes of both lizards suggests that the Bkm-related repeats on sex chromosomes in snakes and other vertebrates evolved convergently. The comparison of microsatellite sequences accumulated on sex chromosomes in E. velox and in other eukaryotic organisms suggests that historical contingency, not characteristics of particular sequences, plays a major role in the determination of which microsatellite sequence is accumulated on the sex chromosomes in a particular lineage. PMID:22013909

  7. Differential immunolocalization of a putative Rec8p in meiotic autosomes and sex chromosomes of triatomine bugs.

    PubMed

    Pigozzi, M I; Solari, A J

    2003-07-01

    Hemipteran chromosomes are holocentric and show regular, special behavior at meiosis. While the autosomes pair at pachytene, have synaptonemal complexes (SCs) and recombination nodules (RNs) and segregate at anaphase I, the sex chromosomes do not form an SC or RNs, divide equationally at anaphase I, and their chromatids segregate at anaphase II. Here we show that this behavior is shared by the X and Y chromosomes of Triatoma infestans and the X(1)X(2)Y chromosomes of Triatoma pallidipennis. As Rec8p is a widely occurring component of meiotic cohesin, involved in meiotic homolog segregation, we used an antibody against Rec8p of Caenorhabditis elegans for immunolocalization in these triatomines. We show that while Rec8p is colocalized with SCs in the autosomes, no Rec8p can be found by immunolabeling in the sex chromosomes at any stage of meiosis. Furthermore, Rec8p labeling is lost from autosomal bivalents prior to metaphase I. In both triatomine species the sex chromosomes conjoin with each other during prophase I, and lack any SC, but they form "fuzzy cores", which are observed with silver staining and with light and electron microscopy during pachytene. Thin, serial sectioning and electron microscopy of spermatocytes at metaphases I and II reveals differential behavior of the sex chromosomes. At metaphase I the sex chromosomes form separate entities, each surrounded by a membranous sheath. On the other hand, at metaphase II the sex chromatids are closely tied and surrounded by a shared membranous sheath. The peculiar features of meiosis in these hemipterans suggest that they depart from the standard meiotic mechanisms proposed for other organisms. PMID:12707778

  8. Acute myeloid leukemia with complex karyotypes and abnormal chromosome 21: Amplification discloses overexpression of APP, ETS2, and ERG genes.

    PubMed

    Baldus, Claudia D; Liyanarachchi, Sandya; Mrózek, Krzysztof; Auer, Herbert; Tanner, Stephan M; Guimond, Martin; Ruppert, Amy S; Mohamed, Nehad; Davuluri, Ramana V; Caligiuri, Michael A; Bloomfield, Clara D; de la Chapelle, Albert

    2004-03-16

    Molecular mechanisms of leukemogenesis have been successfully unraveled by studying genes involved in simple rearrangements including balanced translocations and inversions. In contrast, little is known about genes altered in complex karyotypic abnormalities. We studied acute myeloid leukemia (AML) patients with complex karyotypes and abnormal chromosome 21. High-resolution bacterial artificial chromosome (BAC) array-based comparative genomic hybridization disclosed amplification predominantly in the 25- to 30-megabase (MB) region that harbors the APP gene (26.3 MB) and at position 38.7-39.1 MB that harbors the transcription factors ERG and ETS2. Using oligonucleotide arrays, APP was by far the most overexpressed gene (mean fold change 19.74, P = 0.0003) compared to a control group of AML with normal cytogenetics; ERG and ETS2 also ranked among the most highly expressed chromosome 21 genes. Overexpression of APP and ETS2 correlated with genomic amplification, but high APP expression occurred even in a subset of AML patients with normal cytogenetics (10 of 64, 16%). APP encodes a glycoprotein of unknown function previously implicated in Alzheimer's disease, but not in AML. We hypothesize that APP and the transcription factors ERG and ETS2 are altered by yet unknown molecular mechanisms involved in leukemogenesis. Our results highlight the value of molecularly dissecting leukemic cells with complex karyotypes. PMID:15007164

  9. Use of laser microdissection for the construction of Humulus japonicus Siebold et Zuccarini, 1846 (Cannabaceae) sex chromosome-specific DNA library and cytogenetics analysis

    PubMed Central

    Yakovin, Nickolay A.; Divashuk, Mikhail G.; Razumova, Olga V.; Soloviev, Alexander A.; Karlov, Gennady I.

    2014-01-01

    Abstract Dioecy is relatively rare among plant species, and distinguishable sex chromosomes have been reported in few dioecious species. The multiple sex chromosome system (XX/XY1Y2) of Humulus japonicus Siebold et Zuccarini, 1846 differs from that of other members of the family Cannabaceae, in which the XX/XY chromosome system is present. Sex chromosomes of Humulus japonicus were isolated from meiotic chromosome spreads of males by laser microdissection with the P.A.L.M. MicroLaser system. The chromosomal DNA was directly amplified by degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR). Fast fluorescence in situ hybridization (FAST-FISH) using a labeled, chromosome-specific DOP-PCR product as a probe showed preferential hybridization to sex chromosomes. In addition, the DOP-PCR product was used to construct a short-insert, Humulus japonicus sex chromosomes-specific DNA library. The randomly sequenced clones showed that about 12% of them have significant homology to Humulus lupulus and 88% to Cannabis sativa Linnaeus, 1753 sequences from GenBank database. Forty-four percent of the sequences show homology to plant retroelements. It was concluded that laser microdissection is a useful tool for isolating the DNA of sex chromosomes of Humulus japonicus and for the construction of chromosome-specific DNA libraries for the study of the structure and evolution of sex chromosomes. The results provide the potential for identifying unique or sex chromosome-specific sequence elements in Humulus japonicus and could aid in the identification of sex chromosome-specific repeat and coding regions through chromosome isolation and genome complexity reduction. PMID:25610546

  10. Expansion of the pseudo-autosomal region and ongoing recombination suppression in the Silene latifolia sex chromosomes.

    PubMed

    Bergero, Roberta; Qiu, Suo; Forrest, Alan; Borthwick, Helen; Charlesworth, Deborah

    2013-07-01

    There are two very interesting aspects to the evolution of sex chromosomes: what happens after recombination between these chromosome pairs stops and why suppressed recombination evolves. The former question has been intensively studied in a diversity of organisms, but the latter has been studied largely theoretically. To obtain empirical data, we used codominant genic markers in genetic mapping of the dioecious plant Silene latifolia, together with comparative mapping of S. latifolia sex-linked genes in S. vulgaris (a related hermaphrodite species without sex chromosomes). We mapped 29 S. latifolia fully sex-linked genes (including 21 newly discovered from transcriptome sequencing), plus 6 genes in a recombining pseudo-autosomal region (PAR) whose genetic map length is ?25 cM in both male and female meiosis, suggesting that the PAR may contain many genes. Our comparative mapping shows that most fully sex-linked genes in S. latifolia are located on a single S. vulgaris linkage group and were probably inherited from a single autosome of an ancestor. However, unexpectedly, our maps suggest that the S. latifolia PAR region expanded through translocation events. Some genes in these regions still recombine in S. latifolia, but some genes from both addition events are now fully sex-linked. Recombination suppression is therefore still ongoing in S. latifolia, and multiple recombination suppression events have occurred in a timescale of few million years, much shorter than the timescale of formation of the most recent evolutionary strata of mammal and bird sex chromosomes. PMID:23733786

  11. Abnormal X : autosome ratio, but normal X chromosome inactivation in human triploid cultures

    Microsoft Academic Search

    Kartik R Varadarajan; Ping Luo; Thomas H Norwood; Theresa K Canfield; R Scott Hansen

    2006-01-01

    BACKGROUND: X chromosome inactivation (XCI) is that aspect of mammalian dosage compensation that brings about equivalence of X-linked gene expression between females and males by inactivating one of the two X chromosomes (Xi) in normal female cells, leaving them with a single active X (Xa) as in male cells. In cells with more than two X's, but a diploid autosomal

  12. Many X-linked microRNAs escape meiotic sex chromosome inactivation

    PubMed Central

    Song, Rui; Ro, Seungil; Michaels, Jason D.; Park, Chanjae; McCarrey, John R.; Yan, Wei

    2009-01-01

    Meiotic sex chromosome inactivation (MSCI) during spermatogenesis is characterized by transcriptional silencing of genes on both the X and Y chromosomes in mid to late pachytene spermatocytes1. MSCI is believed to result from meiotic silencing of unpaired DNA because the X and Y chromosomes remain largely unpaired throughout first meiotic prophase2. However, unlike X-chromosome inactivation in female embryonic cells, where 25–30% of X-linked structural genes have been reported to escape inactivation3, previous microarray4- and RT-PCR5-based studies of expression of >364 X-linked mRNA-encoding genes during spermatogenesis have failed to reveal any X-linked gene that escapes the silencing effects of MSCI in primary spermatocytes. Here we show that many X-linked miRNAs are transcribed and processed in pachytene spermatocytes. This unprecedented escape from MSCI by these X-linked miRNAs suggests that they may participate in a critical function at this stage of spermatogenesis, including the possibility that they contribute to the process of MSCI itself, and/or that they may be essential for post-transcriptional regulation of autosomal mRNAs during the late meiotic and early postmeiotic stages of spermatogenesis. PMID:19305411

  13. Cytogenetics of bisexual\\/unisexual species of Poecilia. IV. Sex chromosomes, sex chromatin composition and Ag-NOR polymorphisms in Poecilia latipinna: a population from Mexico

    Microsoft Academic Search

    Luciana Sola; Simona Bressanello; Ellen M Rasch; Paul J Monaco

    1993-01-01

    Cytogenetic analysis using C-banding, silver staining and fluorescent staining was carried out on a population sample of Poecilia latipinna derived from Tampico, Mexico, to verify the presence of sex chromosomes in individuals from the southern areas of this species range and to investigate the extent of C-band and Ag-NOR polymorphisms. Females were found to have W heteromorphic chromosomes, with large

  14. Multiple nuclear gene phylogenetic analysis of the evolution of dioecy and sex chromosomes in the genus Silene.

    PubMed

    Marais, Gabriel A B; Forrest, Alan; Kamau, Esther; Käfer, Jos; Daubin, Vincent; Charlesworth, Deborah

    2011-01-01

    In the plant genus Silene, separate sexes and sex chromosomes are believed to have evolved twice. Silene species that are wholly or largely hermaphroditic are assumed to represent the ancestral state from which dioecy evolved. This assumption is important for choice of outgroup species for inferring the genetic and chromosomal changes involved in the evolution of dioecy, but is mainly based on data from a single locus (ITS). To establish the order of events more clearly, and inform outgroup choice, we therefore carried out (i) multi-nuclear-gene phylogenetic analyses of 14 Silene species (including 7 hermaphrodite or gynodioecious species), representing species from both Silene clades with dioecious members, plus a more distantly related outgroup, and (ii) a BayesTraits character analysis of the evolution of dioecy. We confirm two origins of dioecy within this genus in agreement with recent work on comparing sex chromosomes from both clades with dioecious species. We conclude that sex chromosomes evolved after the origin of Silene and within a clade that includes only S. latifolia and its closest relatives. We estimate that sex chromosomes emerged soon after the split with the ancestor of S. viscosa, the probable closest non-dioecious S. latifolia relative among the species included in our study. PMID:21853022

  15. Cytogenetic analysis of Lagria villosa (Coleoptera, Tenebrionidae): emphasis on the mechanism of association of the Xy(p) sex chromosomes.

    PubMed

    Goll, L G; Artoni, R F; Vicari, M R; Nogaroto, V; Petitpierre, E; Almeida, M C

    2013-01-01

    The Xy(p) sex determination mechanism is the system most frequent and ancestral to Coleoptera. Moreover, the presence of argyrophilous material associated with the sex bivalent is described as being responsible for the maintenance and association of these chromosomes. There are no karyotype data available regarding the genus Lagria and no consensus in the literature regarding the argyrophilous material present in the lumen of sex bivalent. Therefore, the aim of this work was to investigate the mechanism of sex chromosome bivalent association in Lagria villosa by analyzing the argyrophilous nature of the material present in the Xy(p) lumen. It was also intended to characterize L. villosa cytogenetically. The analysis of meiotic cells showed 2n = 18 = 16+Xy(p) for males and 2n = 18 = 16+XX in females and the meiotic formula was 2n = 8(II)+Xy(p). The C-banding showed blocks of pericentromeric heterochromatin in all chromosomes except in the y(p) chromosome. In these regions, the use of fluorochromes revealed the presence of heterochromatin containing GC rich DNA sequences. The study of synaptonemal complex showed a gradual increase in the electron-density of the axial elements of the sex chromosomes and their association with strongly electron-dense material. The pepsin pretreatment revealed that the material impregnated by silver is protein. PMID:22948411

  16. Msh2 deficiency leads to chromosomal abnormalities, centrosome amplification, and telomere capping defect

    SciTech Connect

    Wang, Yisong [ORNL; Liu, Yie [ORNL

    2006-01-01

    Msh2 is a key mammalian DNA mismatch repair (MMR) gene and mutations or deficiencies in mammalian Msh2 gene result in microsatellite instability (MSI+) and the development of cancer. Here, we report that primary mouse embryonic fibroblasts (MEFs) deficient in the murine MMR gene Msh2 (Msh2-/-) showed a significant increase in chromosome aneuploidy, centrosome amplification, and defective mitotic spindle organization and unequal chromosome segregation. Although Msh2-/- mouse tissues or primary MEFs had no apparent change in telomerase activity, telomere length, or recombination at telomeres, Msh2-/- MEFs showed an increase in chromosome end-to-end fusions or chromosome ends without detectable telomeric DNA. These data suggest that MSH2 helps to maintain genomic stability through the regulation of the centrosome and normal telomere capping in vivo and that defects in MMR can contribute to oncogenesis through multiple pathways.

  17. Morphometric differentiation in Cornops aquaticum (Orthoptera: Acrididae): associations with sex, chromosome, and geographic conditions.

    PubMed

    Romero, María Luciana; Colombo, Pablo César; Remis, María Isabel

    2014-01-01

    The water-hyacinth grasshopper Cornops aquaticum (Bruner) (Orthoptera: Acrididae) is native to South America and inhabits lowlands from southern Mexico to central Argentina and Uruguay. This grasshopper feeds and lays eggs on species from the genera Eichhornia and Pontederia. Particularly, Eichhornia crassipes is considered "the world's worst water weed," and the release of C. aquaticum was proposed as a form of biological control. Morphometric variation on the chromosomally differentiated populations from the middle and lower Paraná River and its possible association with geographic, sex, and chromosomal conditions was analyzed. Significant phenotype variation in C. aquaticum population was detected. C. aquaticum presents body-size sexual dimorphism, females being bigger than males. Female-biased sexual size dimorphism for all five analyzed traits was detected. The assessment of variation in sexual size dimorphism for tegmen length showed that this trait scaled allometrically, indicating that males and females did not vary in a similar fashion. The detected allometry was consistent with Rensch's rule demonstrating greater evolutionary divergence in male size than in female size and suggests that males are more sensitive to environmental condition. The analysis of morphometric variation in the context of chromosome constitution showed that the presence of fusion 1/6 was related to body-size variation. Fusion carriers displayed bigger body size than standard homozygotes. Besides, a positive relationship between tegmen length and the number of fused chromosomes was detected, showing a chromosome dose effect. Because the highest frequency of fusions has been found in the lower Paraná River, a marginal environment for this species, the results found would support the hypothesis that some supergenes located in the fusions may be favored in the southern populations, thus contributing to the establishment and maintenance of the polymorphism. PMID:25399431

  18. Sensitive and specific detection of mosaic chromosomal abnormalities using the Parent-of-Origin-based Detection (POD) method

    PubMed Central

    2013-01-01

    Background Mosaic somatic alterations are present in all multi-cellular organisms, but the physiological effects of low-level mosaicism are largely unknown. Most mosaic alterations remain undetectable with current analytical approaches, although the presence of such alterations is increasingly implicated as causative for disease. Results Here, we present the Parent-of-Origin-based Detection (POD) method for chromosomal abnormality detection in trio-based SNP microarray data. Our software implementation, triPOD, was benchmarked using a simulated dataset, outperformed comparable software for sensitivity of abnormality detection, and displayed substantial improvement in the detection of low-level mosaicism while maintaining comparable specificity. Examples of low-level mosaic abnormalities from a large autism dataset demonstrate the benefits of the increased sensitivity provided by triPOD. The triPOD analyses showed robustness across multiple types of Illumina microarray chips. Two large, clinically-relevant datasets were characterized and compared. Conclusions Our method and software provide a significant advancement in the ability to detect low-level mosaic abnormalities, thereby opening new avenues for research into the implications of mosaicism in pathogenic and non-pathogenic processes. PMID:23724825

  19. Abnormal meiotic recombination with complex chromosomal rearrangement in an azoospermic man.

    PubMed

    Wang, Liu; Iqbal, Furhan; Li, Guangyuan; Jiang, Xiaohua; Bukhari, Ihtisham; Jiang, Hanwei; Yang, Qingling; Zhong, Liangwen; Zhang, Yuanwei; Hua, Juan; Cooke, Howard J; Shi, Qinghua

    2015-06-01

    Spermatocyte spreading and immunostaining were applied to detect meiotic prophase I progression, homologous chromosome pairing, synapsis and recombination in an azoospermic reciprocal translocation 46, XY, t(5;7;9;13)(5q11;7p11;7p15;9q12;13p12) carrier. Histological examination of the haematoxylin and eosin stained testicular sections revealed reduced germ cells with no spermatids or sperm in the patient. TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling assay showed apoptotic cells in testicular sections of translocation carrier. Immnunofluorescence analysis indicated the presence of an octavalent in all the pachytene spermatocytes analysed in the patient. Meiotic progression was disturbed, as an increase in zygotene (P < 0.001) and decrease in the pachytene spermatocytes (P < 0.001) were observed in the t(5;7;9;13) carrier compared with controls. It was further observed that 93% of octavalents were found partially asynapsed between homologous chromosomes. A significant decrease in the recombination frequency was observed on 5p, 5q, 7q, 9p and 13q in the translocation carrier compared with the reported controls. A significant reduction in XY recombination frequency was also found in the participants. Our results indicated that complex chromosomal rearrangements can impair synaptic integrity of translocated chromosomes, which may reduce chromosomal recombination on translocated as well as non-translocated chromosomes, a phenomenon commonly known as interchromosomal effect. PMID:25892501

  20. The origin of a selfish B chromosome triggering paternal sex ratio in the parasitoid wasp Trichogramma kaykai

    PubMed Central

    Van Vugt, Joke J. F. A.; de Jong, Hans; Stouthamer, Richard

    2009-01-01

    This study uses molecular and cytogenetic methods to determine the origin of a B chromosome in some males of the wasp Trichogramma kaykai. This so-called paternal sex ratio (PSR) chromosome transmits only through sperm and shortly after fertilization triggers degeneration of the paternal genome, while keeping itself intact. The resulting embryos develop into haploid B-chromosome-carrying males. Another PSR chromosome with a very similar mode of action is found in the distantly related wasp Nasonia vitripennis and its origin was traced by transposon similarity to the genus Trichomalopsis, which is closely related to Nasonia. To determine whether both PSR chromosomes have a similar origin we aimed to reveal the origin of the Trichogramma PSR chromosome. Using fluorescent in situ hybridization, we discovered a major satellite repeat on the PSR chromosome, the 45S ribosomal DNA. Analysis of the internal transcribed spacer 2 (ITS2) of this repeat showed the presence of multiple ITS2 sequences on the PSR chromosome resembling either the ITS2 of T. oleae or of T. kaykai. We therefore conclude that the Trichogramma PSR chromosome originates from T. oleae or a T. oleae-like species. Our results are consistent with different origins for the PSR chromosomes in Trichogramma and Nasonia. PMID:19740887

  1. FAST-FISH with laser beam microdissected DOP-PCR probe distinguishes the sex chromosomes of Silene latifolia

    Microsoft Academic Search

    Roman Hobza; Martina Lengerova; Halina Cernohorska; Jiri Rubes; Boris Vyskot

    2004-01-01

    We present an improved FISH strategy for differentiating the sex chromosomes of the dioecious model plant, Silene latifolia. Fixed mitotic protoplasts were dropped on a polyethylene naphthalate membrane, the X or Y chromosomes were isolated using\\u000a nitrogen laser beam microdissection, catapulted by laser pressure, and amplified by DOP-PCR. A modified FAST-FISH protocol\\u000a based on a short hybridization time combined with

  2. Incomplete Sex Chromosome Dosage Compensation in the Indian Meal Moth, Plodia interpunctella, Based on De Novo Transcriptome Assembly

    PubMed Central

    Harrison, Peter W.; Mank, Judith E.; Wedell, Nina

    2012-01-01

    Males and females experience differences in gene dose for loci in the nonrecombining region of heteromorphic sex chromosomes. If not compensated, this leads to expression imbalances, with the homogametic sex on average exhibiting greater expression due to the doubled gene dose. Many organisms with heteromorphic sex chromosomes display global dosage compensation mechanisms, which equalize gene expression levels between the sexes. However, birds and Schistosoma have been previously shown to lack chromosome-wide dosage compensation mechanisms, and the status in other female heterogametic taxa including Lepidoptera remains unresolved. To further our understanding of dosage compensation in female heterogametic taxa and to resolve its status in the lepidopterans, we assessed the Indian meal moth, Plodia interpunctella. As P. interpunctella lacks a complete reference genome, we conducted de novo transcriptome assembly combined with orthologous genomic location prediction from the related silkworm genome, Bombyx mori, to compare Z-linked and autosomal gene expression levels for each sex. We demonstrate that P. interpunctella lacks complete Z chromosome dosage compensation, female Z-linked genes having just over half the expression level of males and autosomal genes. This finding suggests that the Lepidoptera and possibly all female heterogametic taxa lack global dosage compensation, although more species will need to be sampled to confirm this assertion. PMID:23034217

  3. Incomplete sex chromosome dosage compensation in the Indian meal moth, Plodia interpunctella, based on de novo transcriptome assembly.

    PubMed

    Harrison, Peter W; Mank, Judith E; Wedell, Nina

    2012-01-01

    Males and females experience differences in gene dose for loci in the nonrecombining region of heteromorphic sex chromosomes. If not compensated, this leads to expression imbalances, with the homogametic sex on average exhibiting greater expression due to the doubled gene dose. Many organisms with heteromorphic sex chromosomes display global dosage compensation mechanisms, which equalize gene expression levels between the sexes. However, birds and Schistosoma have been previously shown to lack chromosome-wide dosage compensation mechanisms, and the status in other female heterogametic taxa including Lepidoptera remains unresolved. To further our understanding of dosage compensation in female heterogametic taxa and to resolve its status in the lepidopterans, we assessed the Indian meal moth, Plodia interpunctella. As P. interpunctella lacks a complete reference genome, we conducted de novo transcriptome assembly combined with orthologous genomic location prediction from the related silkworm genome, Bombyx mori, to compare Z-linked and autosomal gene expression levels for each sex. We demonstrate that P. interpunctella lacks complete Z chromosome dosage compensation, female Z-linked genes having just over half the expression level of males and autosomal genes. This finding suggests that the Lepidoptera and possibly all female heterogametic taxa lack global dosage compensation, although more species will need to be sampled to confirm this assertion. PMID:23034217

  4. Specific gene expression profiles and chromosomal abnormalities are associated with infant disseminated neuroblastoma

    PubMed Central

    2009-01-01

    Background Neuroblastoma (NB) tumours have the highest incidence of spontaneous remission, especially among the stage 4s NB subgroup affecting infants. Clinical distinction of stage 4s from lethal stage 4 can be difficult, but critical for therapeutic decisions. The aim of this study was to investigate chromosomal alterations and differential gene expression amongst infant disseminated NB subgroups. Methods Thirty-five NB tumours from patients diagnosed at < 18 months (25 stage 4 and 10 stage 4s), were evaluated by allelic and gene expression analyses. Results All stage 4s patients underwent spontaneous remission, only 48% stage 4 patients survived despite combined modality therapy. Stage 4 tumours were 90% near-diploid/tetraploid, 44% MYCN amplified, 77% had 1p LOH (50% 1p36), 23% 11q and/or 14q LOH (27%) and 47% had 17q gain. Stage 4s were 90% near-triploid, none MYCN amplified and LOH was restricted to 11q. Initial comparison analyses between stage 4s and 4 < 12 months tumours revealed distinct gene expression profiles. A significant portion of genes mapped to chromosome 1 (P < 0.0001), 90% with higher expression in stage 4s, and chromosome 11 (P = 0.0054), 91% with higher expression in stage 4. Less definite expression profiles were observed between stage 4s and 4 < 18m, yet, association with chromosomes 1 (P < 0.0001) and 11 (P = 0.005) was maintained. Distinct gene expression profiles but no significant association with specific chromosomal region localization was observed between stage 4s and stage 4 < 18 months without MYCN amplification. Conclusion Specific chromosomal aberrations are associated with distinct gene expression profiles which characterize spontaneously regressing or aggressive infant NB, providing the biological basis for the distinct clinical behaviour. PMID:19192278

  5. Neurodevelopmental and behavioral abnormalities associated with deletion of chromosome 9p.

    PubMed

    Eshel, Gideon; Lahat, Eli; Reish, Orit; Barr, Joseph

    2002-01-01

    We report a child with craniosynostosis, partial absence of the corpus callosum, developmental delay, precocious puberty, and deletion of chromosome 9(p12p13,3). A review of the literature did not reveal any previous combination of the same kind. Craniosynostosis and partial absence of the corpus callosum, separately or in conjunction, may be part of the spectrum of malformations in the chromosome 9p deletion syndrome, and its presence, in combination with other known features, should prompt a search for this particular deletion as part of the differential diagnosis. PMID:11913572

  6. Evolutionary erosion of yeast sex chromosomes by mating-type switching accidents

    PubMed Central

    Gordon, Jonathan L.; Armisén, David; Proux-Wéra, Estelle; ÓhÉigeartaigh, Seán S.; Byrne, Kevin P.; Wolfe, Kenneth H.

    2011-01-01

    We investigate yeast sex chromosome evolution by comparing genome sequences from 16 species in the family Saccharomycetaceae, including data from genera Tetrapisispora, Kazachstania, Naumovozyma, and Torulaspora. We show that although most yeast species contain a mating-type (MAT) locus and silent HML and HMR loci structurally analogous to those of Saccharomyces cerevisiae, their detailed organization is highly variable and indicates that the MAT locus is a deletion hotspot. Over evolutionary time, chromosomal genes located immediately beside MAT have continually been deleted, truncated, or transposed to other places in the genome in a process that is gradually shortening the distance between MAT and HML. Each time a gene beside MAT is removed by deletion or transposition, the next gene on the chromosome is brought into proximity with MAT and is in turn put at risk for removal. This process has also continually replaced the triplicated sequence regions, called Z and X, that allow HML and HMR to be used as templates for DNA repair at MAT during mating-type switching. We propose that the deletion and transposition events are caused by evolutionary accidents during mating-type switching, combined with natural selection to keep MAT and HML on the same chromosome. The rate of deletion accelerated greatly after whole-genome duplication, probably because genes were redundant and could be deleted without requiring transposition. We suggest that, despite its mutational cost, switching confers an evolutionary benefit by providing a way for an isolated germinating spore to reform spores if the environment is too poor. PMID:22123960

  7. A Gradual Process of Recombination Restriction in the Evolutionary History of the Sex Chromosomes in Dioecious Plants

    Microsoft Academic Search

    Michael Nicolas; Gabriel Marais; Vladka Hykelova; Bohuslav Janousek; Valérie Laporte; Boris Vyskot; Dominique Mouchiroud; Ioan Negrutiu; Deborah Charlesworth; Françoise Monéger

    2005-01-01

    To help understand the evolution of suppressed recombination between sex chromosomes, and its consequences for evolution of the sequences of Y-linked genes, we have studied four X-Y gene pairs, including one gene not previously characterized, in plants in a group of closely related dioecious species of Silene which have an X-Y sex-determining system (S. latifolia, S. dioica, and S. diclinis).

  8. Abnormal Pap tests and human papillomavirus infections among HIV infected and uninfected women who have sex with women

    PubMed Central

    Massad, L. Stewart; Xie, Xianhong; Minkoff, Howard; Darragh, Teresa M.; D’Souza, Gypsyamber; Sanchez-Keeland, Lorraine; Watts, D. Heather; Colie, Christine; Strickler, Howard D.

    2014-01-01

    Objective To estimate the frequency of abnormal Pap and human papillomavirus (HPV) positivity among HIV seropositive and seronegative women who have sex with women (WSW). Methods Pap and HPV DNA PCR tests were obtained every six months from women in a U.S. cohort of HIV seropositive and seronegative women. WSW were women reporting no male and at least one female sex partner over five years. WSW were frequency matched 1:5 to women reporting sex only with men (WSM) and assessed using multivariable generalized estimating equation logistic regression models. Results Paps at study entry were abnormal in 12 (21%) of 49 HIV seropositive WSW, 151 (64%) of 245 HIV seropositive WSM, 3 (9%) of 24 HIV seronegative WSW, and 16 (11%) of 120 seronegative WSM. HPV was found at entry in 18 (42%) HIV seropositive WSW, 109 (52%) HIV seropositive WSM, 6 (27%) HIV seronegative WSW and 13 (13%) HIV seronegative WSM. After controlling for HIV serostatus and CD4 count, WSW had marginally lower odds than WSM of Pap abnormality (O.R. 0.59, 95% C.I. 0.33, 1.03) and of HPV (O.R. 0.53, 95% C.I. 0.32, 0.89). After controlling for partner gender, HIV seropositivity and lower CD4 count were associated with any HPV, oncogenic HPV, any abnormal Pap result, and HSIL or worse (P < 0.0001 for all). Conclusion While risks for abnormal Pap and HPV are modestly lower in WSW than WSM, both are common in HIV seropositive women regardless of sexual preference. WSW and WSM should be screened similarly. PMID:23959300

  9. COMMON TYPES OF CHROMOSOME ABNORMALITIES Dr. Fern Tsien, Dept. of Genetics, LSUHSC, NO, LA

    E-print Network

    Syndrome Society, there are more than 400,000 individuals with Down syndrome in the United States. Patients with Down syndrome have three copies of their 21 chromosomes instead of the normal two. The major clinical features of Down syndrome patients include low muscle tone, small stature, an upward slant to the eyes

  10. Familial X-linked mental retardation with an X chromosome abnormality

    Microsoft Academic Search

    J Harvey; C Judge; S Wiener

    1977-01-01

    An X-linked pattern of transmission observed in four families with familial mental retardation in several generations was associated with a probable secondary constriction at the distal end of the q arms of the X chromosome. Twenty retarded males and no retarded females were observed. All available live retarded males and most of their normal mothers were found to have the

  11. Prevalence of chromosomal abnormalities and timing of karyotype analysis in patients with recurrent implantation failure (RIF) following assisted reproduction

    PubMed Central

    De Sutter, P.; Stadhouders, R.; Dutré, M.; Gerris, J.; Dhont, M.

    2012-01-01

    Aims: To analyze the prevalence and type of karyotype abnormalities in RIF patients and to evaluate the adequate timing for analysis and the presence of possible risk factors. Methods: 615 patients (317 women and 298 men) with RIF, having undergone at least 3 sequential failed IVF/ICSI cycles prior to karyotype analysis, were included in this study. Anomaly rates found were compared with published series. Results: Chromosomal abnormalities were diagnosed in 2.1% of patients (13/615): 8 females (2.5%) and 5 males (1.7%) which is significantly higher for the females than in unselected newborns (0.8%) and normo-ovulatory women (0.6%) but lower than in women with high-order implantation failure (10.8%). No significant differences were found with couples at the start of IVF/ICSI (2.0%). Karyotyping all patients prior to IVF/ICSI results in a higher cost than selecting RIF patients. Two subgroups showed an increased prevalence of abnormalities: secondary infertile women with a history of only miscarriages (9.1%) and women with female infertility (6.0%). Conclusion: A karyotype analysis is indicated in all women with RIF. Nulliparous women with a history of miscarriage and women with documented infertility are at greater risk of CA and are to be advised to undergo karyotyping. PMID:24753890

  12. Rates of trisomies 21, 18, 13 and other chromosome abnormalities in about 20 000 prenatal studies compared with estimated rates in live births

    Microsoft Academic Search

    Dina M. Schreinemachers; Philip K. Cross; Ernest B. Hook

    1982-01-01

    Data were analyzed on the results of 19675 prenatal cytogenetic diagnoses reported to two chromosome registries on women aged 35 or over for whom there was no known cytogenetic risk for a chromosome abnormality except parental age. The expected rates at amniocentesis of 47,+21; 47,+18; 47,+13; XXX; XXY; XYY; and other clinically significant cytogenetic defects by maternal age were obtained

  13. Detection of chromosomal abnormalities in chronic lymphocytic leukemia increased by interphase fluorescence in situ hybridization in tetradecanoylphorbol acetate–stimulated peripheral blood cells

    Microsoft Academic Search

    Jana Sánchez; Anna Aventín

    2007-01-01

    Interphase fluorescent in situ hybridization on unstimulated peripheral blood mononuclear cells (I-FISH-PBMC) is used to detect chromosomal abnormalities such as 11q?, 13q?, 17p?, and trisomy 12 in chronic lymphocytic leukemia (CLL). A total of 56 samples from 49 patients with CLL were studied using commercially available probes for chromosome regions 11q22.3 (ATM), 13q14 (13S272), 17p13 (p53) and 12 centromere (D12Z3).

  14. Resolution of sex chromosome constitution by genomic in situ hybridization and fluorescence in situ hybridization with (TTAGG) n telomeric probe in some species of Lepidoptera

    Microsoft Academic Search

    Atsuo Yoshido; František Marec; Ken Sahara

    2005-01-01

    We have developed a simple method to resolve the sex chromosome constitution in females of Lepidoptera by using a combination\\u000a of genomic in situ hybridization (GISH) and fluorescence in situ hybridization with (TTAGG)\\u000a n\\u000a telomeric probe (telomere-FISH). In pachytene configurations of sex chromosomes, GISH differentiated W heterochromatin and\\u000a telomere-FISH detected the chromosome ends. With this method we showed that Antheraea

  15. The roles of Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes in sex determination and differentiation mechanisms: Ubiquity and diversity across the animal kingdom.

    PubMed

    Picard, Marion Anne-Lise; Cosseau, Céline; Mouahid, Gabriel; Duval, David; Grunau, Christoph; Toulza, Čve; Allienne, Jean-François; Boissier, Jérôme

    2015-07-01

    The Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes have been intensively studied because they represent major transcription factors in the pathways governing sex determination and differentiation. These genes have been identified in animal groups ranging from cnidarians to mammals, and some of the genes functionally studied. Here, we propose to analyze (i) the presence/absence of various Dmrt gene groups in the different taxa across the animal kingdom; (ii) the relative expression levels of the Dmrt genes in each sex; (iii) the specific spatial (by organ) and temporal (by developmental stage) variations in gene expression. This review considers non-mammalian animals at all levels of study (i.e. no particular importance is given to animal models), and using all types of sexual strategy (hermaphroditic or gonochoric) and means of sex determination (i.e. genetic or environmental). To conclude this global comparison, we offer an analysis of the DM domains conserved among the different DMRT proteins, and propose a general sex-specific pattern for each member of the Dmrt gene family. PMID:26043799

  16. Cytogenetic abnormalities in Tunisian women with premature ovarian failure.

    PubMed

    Ayed, Wiem; Amouri, Ahlem; Hammami, Wajih; Kilani, Olfa; Turki, Zinet; Harzallah, Fatma; Bouayed-Abdelmoula, Nouha; Chemkhi, Imen; Zhioua, Fethi; Slama, Claude Ben

    2014-12-01

    To identify the distribution of chromosome abnormalities among Tunisian women with premature ovarian failure (POF) referred to the department of Cytogenetic at the Pasteur Institute of Tunis (Tunisia), standard cytogenetic analysis was carried out in a total of 100 women younger than 40 affected with premature ovarian failure. We identified 18 chromosomal abnormalities, including seven X-numerical anomalies in mosaic and non-mosaic state (45,X; 47,XXX), four sex reversal, three X-structural abnormalities (terminal deletion and isochromosomes), one autosomal translocation and one supernumerary marker. The overall prevalence of chromosomal abnormalities was 18% in our cohort. X chromosome aneuploidy was the most frequent aberration. This finding confirms the essential role of X chromosome in ovarian function and underlies the importance of cytogenetic investigations in the routine management of POF. PMID:25433561

  17. Testing for the footprint of sexually antagonistic polymorphisms in the pseudoautosomal region of a plant sex chromosome pair.

    PubMed

    Qiu, Suo; Bergero, Roberta; Charlesworth, Deborah

    2013-07-01

    The existence of sexually antagonistic (SA) polymorphism is widely considered the most likely explanation for the evolution of suppressed recombination of sex chromosome pairs. This explanation is largely untested empirically, and no such polymorphisms have been identified, other than in fish, where no evidence directly implicates these genes in events causing loss of recombination. We tested for the presence of loci with SA polymorphism in the plant Silene latifolia, which is dioecious (with separate male and female individuals) and has a pair of highly heteromorphic sex chromosomes, with XY males. Suppressed recombination between much of the Y and X sex chromosomes evolved in several steps, and the results in Bergero et al. (2013) show that it is still ongoing in the recombining or pseudoautosomal, regions (PARs) of these chromosomes. We used molecular evolutionary approaches to test for the footprints of SA polymorphisms, based on sequence diversity levels in S. latifolia PAR genes identified by genetic mapping. Nucleotide diversity is high for at least four of six PAR genes identified, and our data suggest the existence of polymorphisms maintained by balancing selection in this genome region, since molecular evolutionary (HKA) tests exclude an elevated mutation rate, and other tests also suggest balancing selection. The presence of sexually antagonistic alleles at a locus or loci in the PAR is suggested by the very different X and Y chromosome allele frequencies for at least one PAR gene. PMID:23733787

  18. Genomic Diversity in Two Related Plant Species with and without Sex Chromosomes - Silene latifolia and S. vulgaris

    PubMed Central

    Cegan, Radim; Vyskot, Boris; Kejnovsky, Eduard; Kubat, Zdenek; Blavet, Hana; Šafá?, Jan; Doležel, Jaroslav; Blavet, Nicolas; Hobza, Roman

    2012-01-01

    Background Genome size evolution is a complex process influenced by polyploidization, satellite DNA accumulation, and expansion of retroelements. How this process could be affected by different reproductive strategies is still poorly understood. Methodology/Principal Findings We analyzed differences in the number and distribution of major repetitive DNA elements in two closely related species, Silene latifolia and S. vulgaris. Both species are diploid and possess the same chromosome number (2n?=?24), but differ in their genome size and mode of reproduction. The dioecious S. latifolia (1C?=?2.70 pg DNA) possesses sex chromosomes and its genome is 2.5× larger than that of the gynodioecious S. vulgaris (1C?=?1.13 pg DNA), which does not possess sex chromosomes. We discovered that the genome of S. latifolia is larger mainly due to the expansion of Ogre retrotransposons. Surprisingly, the centromeric STAR-C and TR1 tandem repeats were found to be more abundant in S. vulgaris, the species with the smaller genome. We further examined the distribution of major repetitive sequences in related species in the Caryophyllaceae family. The results of FISH (fluorescence in situ hybridization) on mitotic chromosomes with the Retand element indicate that large rearrangements occurred during the evolution of the Caryophyllaceae family. Conclusions/Significance Our data demonstrate that the evolution of genome size in the genus Silene is accompanied by the expansion of different repetitive elements with specific patterns in the dioecious species possessing the sex chromosomes. PMID:22393373

  19. Frequency of chromosomal abnormalities in early embryos of the domestic sheep (Ovis aries)

    Microsoft Academic Search

    Susan E. Long; C. V. Williams

    1980-01-01

    Summary. Embryos or unfertilized eggs were collected 2 or 3 days post coitum from mature sheep of various breeds and crosses. The karyotypes of 89 of the 376 collected were established. There were 44 embryos with 2n = 54XX, 30 with 2n = 54XY;1 was a 2n\\/1n mosaic; 4 had 2n + 1 chromosomes giving an incidence of trisomy of

  20. The significance of radiation-induced chromosome abnormalities in radiological protection

    PubMed Central

    Dolphin, G. W.; Lloyd, D. C.

    1974-01-01

    A brief review is given of the production and analysis of chromosome aberrations induced by ionizing radiation. The various tissues in which it is possible to demonstrate aberrations are noted and particular emphasis is laid on the culture of peripheral blood lymphocytes. Some examples of recent applications of the technique are described. These are in the determination of suspected overdoses to radiation workers, in estimating doses to radiotherapy patients, and investigating the depth/biological profile for a negative ? meson beam. PMID:4841086

  1. Neurocognitive Outcomes of Individuals with a Sex Chromosome Trisomy: XXX, XYY, or XXY--A Systematic Review

    ERIC Educational Resources Information Center

    Leggett, Victoria; Jacobs, Patricia; Nation, Kate; Scerif, Gaia; Bishop, Dorothy V. M.

    2010-01-01

    Aim: To review systematically the neurodevelopmental characteristics of individuals with sex chromosome trisomies (SCTs). Method: A bibliographic search identified English-language articles on SCTs. The focus was on studies unbiased by clinical referral, with power of at least 0.69 to detect an effect size of 1.0. Results: We identified 35…

  2. Expression in fibroblast culture of the satellited-X chromosome associated with familial sex-linked mental retardation

    Microsoft Academic Search

    P. B. Jacky; F. J. Dill

    1980-01-01

    The satellited-X chromosome previously shown in lymphocyte culture to be associated with certain types of sex-linked mental retardation has, for the first time, been demonstrated in cultured skin fibroblasts and lymphocytes from two affected males and an obligate carrier female. These findings provide a basis for reliable diagnosis of female carriers and for the development of prenatal diagnosis.

  3. Evaluation of chromosomal abnormalities by clg-FISH and association with proliferative and apoptotic indexes in multiple myeloma

    PubMed Central

    Linardi, C.C.G.; Martinez, G.; Velloso, E.D.R.P.; Leal, A.M.; Kumeda, C.A.; Buccheri, V.; Azevedo, R.S.; Peliçario, L.M.; Dorlhiac-Llacer, P.

    2012-01-01

    Eighty-six newly diagnosed multiple myeloma (MM) patients from a public hospital of Săo Paulo (Brazil) were evaluated by cIg-FISH for the presence of del(13)(q14), t(4;14)(p16.3;q32) and del(17)(p13). These abnormalities were observed in 46.5, 9.3, and 7.0% of the patients, respectively. In order to identify the possible role of del(13)(q14) in the physiopathology of MM, we investigated the association between this abnormality and the proliferative and apoptotic indexes of plasma cells. When cases demonstrating t(4;14)(p16.3;q32) and del(17)(p13) were excluded from the analysis, we observed a trend towards a positive correlation between the proportion of cells carrying del(13)(q14) and plasma cell proliferation, determined by Ki-67 expression (r = 0.23, P = 0.06). On the other hand, no correlation between the proportion of cells carrying del(13)(q14) and apoptosis, determined by annexin-V staining, was detected (r = 0.05, P = 0.69). In general, patients carrying del(13)(q14) did not have lower survival than patients without del(13)(q14) (P = 0.15), but patients with more than 80% of cells carrying del(13)(q14) showed a lower overall survival (P = 0.033). These results suggest that, when del(13)(q14) is observed in a high proportion of malignant cells, it may have a role in determining MM prognosis. Another finding was a statistically significant lower overall survival of patients with t(4;14)(p16.3;q32) (P = 0.026). In the present study, almost half the patients with t(4;14)(p16.3;q32) died just after diagnosis, before starting treatment. This fact suggests that, in Săo Paulo, there may be even more patients with this chromosomal abnormality, but they probably die before being diagnosed due to unfavorable socioeconomic conditions. This could explain the low prevalence of this chromosomal abnormality observed in the present study. PMID:22911347

  4. In Situ Gene Mapping of Two Genes Supports Independent Evolution of Sex Chromosomes in Cold-Adapted Antarctic Fish

    PubMed Central

    Ghigliotti, Laura; Cheng, C.-H. Christina; Bonillo, Céline; Coutanceau, Jean-Pierre; Pisano, Eva

    2013-01-01

    Two genes, that is, 5S ribosomal sequences and antifreeze glycoprotein (AFGP) genes, were mapped onto chromosomes of eight Antarctic notothenioid fish possessing a X1X1X2X2/X1X2Y sex chromosome system, namely, Chionodraco hamatus and Pagetopsis macropterus (family Channichthyidae), Trematomus hansoni, T. newnesi, T. nicolai, T. lepidorhinus, and Pagothenia borchgrevinki (family Nototheniidae), and Artedidraco skottsbergi (family Artedidraconidae). Through fluorescence in situ hybridization (FISH), we uncovered distinct differences in the gene content of the Y chromosomes in the eight species, with C. hamatus and P. macropterus standing out among others in bearing 5S rDNA and AFGP sequences on their Y chromosomes, respectively. Both genes were absent from the Y chromosomes of any analyzed species. The distinct patterns of Y and non-Y chromosome association of the 5S rDNA and AFGP genes in species representing different Antarctic fish families support an independent origin of the sex heterochromosomes in notothenioids with interesting implications for the evolutionary/adaptational history of these fishes living in a cold-stable environment. PMID:23509694

  5. In situ gene mapping of two genes supports independent evolution of sex chromosomes in cold-adapted Antarctic fish.

    PubMed

    Ghigliotti, Laura; Cheng, C-H Christina; Bonillo, Céline; Coutanceau, Jean-Pierre; Pisano, Eva

    2013-01-01

    Two genes, that is, 5S ribosomal sequences and antifreeze glycoprotein (AFGP) genes, were mapped onto chromosomes of eight Antarctic notothenioid fish possessing a X1X1X2X2/X1X2Y sex chromosome system, namely, Chionodraco hamatus and Pagetopsis macropterus (family Channichthyidae), Trematomus hansoni, T. newnesi, T. nicolai, T. lepidorhinus, and Pagothenia borchgrevinki (family Nototheniidae), and Artedidraco skottsbergi (family Artedidraconidae). Through fluorescence in situ hybridization (FISH), we uncovered distinct differences in the gene content of the Y chromosomes in the eight species, with C. hamatus and P. macropterus standing out among others in bearing 5S rDNA and AFGP sequences on their Y chromosomes, respectively. Both genes were absent from the Y chromosomes of any analyzed species. The distinct patterns of Y and non-Y chromosome association of the 5S rDNA and AFGP genes in species representing different Antarctic fish families support an independent origin of the sex heterochromosomes in notothenioids with interesting implications for the evolutionary/adaptational history of these fishes living in a cold-stable environment. PMID:23509694

  6. Speech and language development in 41 children with sex chromosome anomalies.

    PubMed

    Bender, B; Fry, E; Pennington, B; Puck, M; Salbenblatt, J; Robinson, A

    1983-02-01

    Forty-one children with sex chromosome anomalies identified from the chromosome screening of a newborn population were blindly evaluated by a speech-language pathologist, along with a control group of 31 siblings. 47,XXX girls and 47,XXY boys were found to have increased problems in auditory perception, receptive language, and expressive language; the problems of the 47,XXY boys were less severe than those of the 47,XXX group, and reflected specific deficits in their ability to process linguistic information rather than a deficit in comprehension. An increased occurrence of speech production problems among the 45,X girls was associated with the presence of oral/structural malformations that often had no measurable effect on their production of speech sounds. Although the 45,X girls and 47,XYY boys had no significant increase of problems in auditory reception, receptive language, and expressive language, the trend of the data suggested more difficulty than in the control groups. The mosaic children were not different from the control subjects. Some children in all groups were found to have normal speech and language development. PMID:6823432

  7. A gradual process of recombination restriction in the evolutionary history of the sex chromosomes in dioecious plants.

    PubMed

    Nicolas, Michael; Marais, Gabriel; Hykelova, Vladka; Janousek, Bohuslav; Laporte, Valérie; Vyskot, Boris; Mouchiroud, Dominique; Negrutiu, Ioan; Charlesworth, Deborah; Monéger, Françoise

    2005-01-01

    To help understand the evolution of suppressed recombination between sex chromosomes, and its consequences for evolution of the sequences of Y-linked genes, we have studied four X-Y gene pairs, including one gene not previously characterized, in plants in a group of closely related dioecious species of Silene which have an X-Y sex-determining system (S. latifolia, S. dioica, and S. diclinis). We used the X-linked copies to build a genetic map of the X chromosomes, with a marker in the pseudoautosomal region (PAR) to orient the map. The map covers a large part of the X chromosomes--at least 50 centimorgans. Except for a recent rearrangement in S. dioica, the gene order is the same in the X chromosomes of all three species. Silent site divergence between the DNA sequences of the X and Y copies of the different genes increases with the genes' distances from the PAR, suggesting progressive restriction of recombination between the X and Y chromosomes. This was confirmed by phylogenetic analyses of the four genes, which also revealed that the least-diverged X-Y pair could have ceased recombining independently in the dioecious species after their split. Analysis of amino acid replacements vs. synonymous changes showed that, with one possible exception, the Y-linked copies appear to be functional in all three species, but there are nevertheless some signs of degenerative processes affecting the genes that have been Y-linked for the longest times. Although the X-Y system evolved quite recently in Silene (less than 10 million years ago) compared to mammals (about 320 million years ago), our results suggest that similar processes have been at work in the evolution of sex chromosomes in plants and mammals, and shed some light on the molecular mechanisms suppressing recombination between X and Y chromosomes. PMID:15630476

  8. Women’s experiences receiving abnormal prenatal chromosomal microarray testing results

    PubMed Central

    Bernhardt, Barbara A.; Soucier, Danielle; Hanson, Karen; Savage, Melissa S.; Jackson, Laird; Wapner, Ronald J.

    2013-01-01

    Purpose Genomic microarrays can detect copy number variants not detectable by conventional cytogenetics. This technology is diffusing rapidly into prenatal settings even though the clinical implications of many copy number variants are currently unknown. We conducted a qualitative pilot study to explore the experiences of women receiving abnormal results from prenatal microarray testing performed in a research setting. Methods Participants were a subset of women participating in a multicenter prospective study “Prenatal Cytogenetic Diagnosis by Array-based Copy Number Analysis”. Telephone interviews were conducted with 23 women receiving abnormal prenatal microarray results. Results We found that five key elements dominated the experiences of women who had received abnormal prenatal microarray results: an offer too good to pass up, blindsided by the results, uncertainty and unquantifiable risks, need for support, and toxic knowledge. Conclusion As prenatal microarray testing is increasingly utilized, uncertain findings will be common resulting in greater need for careful pre and post test counseling, and more education of, and resources for providers so they can adequately support the women who are undergoing testing. PMID:22955112

  9. Delineation of a deletion region critical for corpus callosal abnormalities in chromosome 1q43–q44

    PubMed Central

    Nagamani, Sandesh C Sreenath; Erez, Ayelet; Bay, Carolyn; Pettigrew, Anjana; Lalani, Seema R; Herman, Kristin; Graham, Brett H; Nowaczyk, Malgorzata JM; Proud, Monica; Craigen, William J; Hopkins, Bobbi; Kozel, Beth; Plunkett, Katie; Hixson, Patricia; Stankiewicz, Pawel; Patel, Ankita; Cheung, Sau Wai

    2012-01-01

    Submicroscopic deletions involving chromosome 1q43–q44 result in cognitive impairment, microcephaly, growth restriction, dysmorphic features, and variable involvement of other organ systems. A consistently observed feature in patients with this deletion are the corpus callosal abnormalities (CCAs), ranging from thinning and hypoplasia to complete agenesis. Previous studies attempting to delineate the critical region for CCAs have yielded inconsistent results. We conducted a detailed clinical and molecular characterization of seven patients with deletions of chromosome 1q43–q44. Using array comparative genomic hybridization, we mapped the size, extent, and genomic content of these deletions. Four patients had CCAs, and shared the smallest region of overlap that contains only three protein coding genes, CEP170, SDCCAG8, and ZNF238. One patient with a small deletion involving SDCCAG8 and AKT3, and another patient with an intragenic deletion of AKT3 did not have any CCA, implying that the loss of these two genes is unlikely to be the cause of CCA. CEP170 is expressed extensively in the brain, and encodes for a protein that is a component of the centrosomal complex. ZNF238 is involved in control of neuronal progenitor cells and survival of cortical neurons. Our results rule out the involvement of AKT3, and implicate CEP170 and/or ZNF238 as novel genes causative for CCA in patients with a terminal 1q deletion. PMID:21934713

  10. American College of Medical Genetics and Genomics technical standards and guidelines: microarray analysis for chromosome abnormalities in neoplastic disorders.

    PubMed

    Cooley, Linda D; Lebo, Matthew; Li, Marilyn M; Slovak, Marilyn L; Wolff, Daynna J

    2013-06-01

    Microarray methodologies, to include array comparative genomic hybridization and single-nucleotide polymorphism-based arrays, are innovative methods that provide genomic data. These data should be correlated with the results from the standard methods, chromosome and/or fluorescence in situ hybridization, to ascertain and characterize the genomic aberrations of neoplastic disorders, both liquid and solid tumors. Over the past several decades, standard methods have led to an accumulation of genetic information specific to many neoplasms. This specificity is now used for the diagnosis and classification of neoplasms. Cooperative studies have revealed numerous correlations between particular genetic aberrations and therapeutic outcomes. Molecular investigation of chromosomal abnormalities identified by standard methods has led to discovery of genes, and gene function and dysfunction. This knowledge has led to improved therapeutics and, in some disorders, targeted therapies. Data gained from the higher-resolution microarray methodologies will enhance our knowledge of the genomics of specific disorders, leading to more effective therapeutic strategies. To assist clinical laboratories in validation of the methods, their consistent use, and interpretation and reporting of results from these microarray methodologies, the American College of Medical Genetics and Genomics has developed the following professional standard and guidelines. PMID:23619274

  11. Genetic architecture of isolation between two species of Silene with sex chromosomes and Haldane's rule.

    PubMed

    Demuth, Jeffery P; Flanagan, Rebecca J; Delph, Lynda F

    2014-02-01

    Examination of the genetic architecture of hybrid breakdown can provide insight into the genetic mechanisms of commonly observed isolating phenomena such as Haldane's rule. We used line-cross analysis to dissect the genetic architecture of divergence between two plant species that exhibit Haldane's rule for male sterility and rarity, Silene latifolia and Silene diclinis. We made 15 types of crosses, including reciprocal F1, F2, backcrosses, and later-generation crosses, grew the seeds to flowering, and measured the number of viable ovules, proportion of viable pollen, and sex ratio. Typically, Haldane's rule for male rarity in XY animal hybrids is explained by interactions involving recessive X-linked alleles that are deleterious when hemizygous (dominance theory), whereas sterility is explained by rapid evolution of spermatogenesis genes (faster-male evolution). In contrast, we found that the genetic mechanisms underlying Haldane's rule between the two Silene species did not follow these conventions. Dominance theory was sufficient to explain male sterility, but male rarity likely involved faster-male evolution. We also found an effect of the neo-sex chromosomes of S. diclinis on the extreme rarity of some hybrid males. Our findings suggest that the genetic architecture of Haldane's rule in dioecious plants may differ from those commonly found in animals. PMID:24117135

  12. Expression of pro-EPIL peptides encoded by the insulin-like 4 (INSL4) gene in chromosomally abnormal pregnancies.

    PubMed

    Mock, P; Frydman, R; Bellet, D; Chassin, D; Bischof, P; Campana, A; Bidart, J M

    2000-10-01

    The recent development of a specific immunoassay based on monoclonal antibodies directed to chain C and chain A of early placenta insulin-like peptide (EPIL) encoded by the INSL4 gene, has made it possible to demonstrate pro-EPIL peptide expression during normal pregnancy. In the present study, we report on the expression of pro-EPIL peptides in chromosomally abnormal pregnancies, namely trisomy 21 and 18. EPIL peptide levels were measured in amniotic fluid (AF) and maternal serum (MS) from pregnancies with trisomy 21 (n=16) or 18 (n=14) and compared to levels detected in AF and MS from 33 chromosomally normal pregnancies between 12 and 32 weeks of gestation. Pro-EPIL peptide levels were significantly higher in amniotic fluids from T21 than in AF from chromosomally normal pregnancies (mean pro-EPIL levels +/- SEM, 449+/-129.2 ng/mL vs 137+/-29.6 ng/mL, P = 0.0195), whereas there was only a trend towards an increase in pro-EPIL peptide levels in maternal serum. In a limited matched gestational age range (15 to 17 weeks), it was confirmed that pro-EPIL peptide levels were significantly higher in AF from T21 pregnancies (644.0+/-155.9 ng/mL, n = 11) than in AF from normal pregnancies (177.8+/-39.0 ng/mL, n = 12; P < 0.0001). Interestingly, the expression patterns of pro-EPIL peptides, human chorionic gonadotropin (hCG) and its free subunits were parallel in T21 pregnancies as recently observed in normal pregnancies. These results are in line with previous observations suggesting that the biosynthesis of both hCG and EPIL follows common regulation pathways. PMID:11061561

  13. Absence of correlation between Sry polymorphisms and XY sex reversal caused by the M.m. domesticus Y chromosome

    SciTech Connect

    Carlisle, C.; Nagamine, C.M. [Vanderbilt Univ., School of Medicine, Nashville, TN (United States)] [Vanderbilt Univ., School of Medicine, Nashville, TN (United States); Winkinig, H.; Weichenhan, D. [Medizinische Universitaet Zu Luebeck (Germany)] [Medizinische Universitaet Zu Luebeck (Germany)

    1996-04-01

    Mus musculus domesticus Y chromosomes (Y{sup DOM} Chrs) vary in their ability to induce testes in the strain C57BL/6J. In severe cases, XY females develop (XY{sup DOM} sex reversal). To identify the molecular basis for the sex reversal, a 2.7-kb region of Sry, the testis-determining gene, was sequenced from Y{sup DOM} Chrs linked to normal testis determination, transient sex reversal, and severe sex reversal. Four mutations were identified. However, no correlation exists between these mutations and severity of XY{sup DOM} sex reversal. RT-PCR identified Sry transcripts in XY{sup DOM} sex-reversed fetal gonads at 11 d.p.c., the age when Sry is hypothesized to function. In addition, no correlation exists between XY{sup DOM} sex reversal and copy numbers of pSx1, a Y-repetitive sequence whose deletion is linked to XY sex reversal. We conclude that SRY protein variants, blockade of Sry transcription, and deletion of pSx1 sequences are not the underlying causes of XY{sup DOM} sex reversal. 63 refs., 6 figs., 6 tabs.

  14. Pseudosynapsis and Decreased Stringency of Meiotic Repair Pathway Choice on the Hemizygous Sex Chromosome of Caenorhabditis elegans Males

    PubMed Central

    Checchi, Paula M.; Lawrence, Katherine S.; Van, Mike V.; Larson, Braden J.; Engebrecht, JoAnne

    2014-01-01

    During meiosis, accurate chromosome segregation relies on homology to mediate chromosome pairing, synapsis, and crossover recombination. Crossovers are dependent upon formation and repair of double-strand breaks (DSBs) by homologous recombination (HR). In males of many species, sex chromosomes are largely hemizygous, yet DSBs are induced along nonhomologous regions. Here we analyzed the genetic requirements for meiotic DSB repair on the completely hemizygous X chromosome of Caenorhabditis elegans males. Our data reveal that the kinetics of DSB formation, chromosome pairing, and synapsis are tightly linked in the male germ line. Moreover, DSB induction on the X is concomitant with a brief period of pseudosynapsis that may allow X sister chromatids to masquerade as homologs. Consistent with this, neither meiotic kleisins nor the SMC-5/6 complex are essential for DSB repair on the X. Furthermore, early processing of X DSBs is dependent on the CtIP/Sae2 homolog COM-1, suggesting that as with paired chromosomes, HR is the preferred pathway. In contrast, the X chromosome is refractory to feedback mechanisms that ensure crossover formation on autosomes. Surprisingly, neither RAD-54 nor BRC-2 are essential for DSB repair on the X, suggesting that unlike autosomes, the X is competent for repair in the absence of HR. When both RAD-54 and the structure-specific nuclease XPF-1 are abrogated, X DSBs persist, suggesting that single-strand annealing is engaged in the absence of HR. Our findings indicate that alteration in sister chromatid interactions and flexibility in DSB repair pathway choice accommodate hemizygosity on sex chromosomes. PMID:24939994

  15. Chromosome study of Amazona amazonica and A. aestiva (Aves: Psittaciformes): determination of chromosome number and identification of sex chromosomes by C-banding methods

    Microsoft Academic Search

    R. Aquino; I. Ferrari

    1990-01-01

    Two parrot species, Amazona amazonica and A. aestiva, submitted to cytogenetic analysis presented a diploid chromosome number of 2n=70 (20M+50m). With the C-banding pattern, the cells of female speciments showed an almost totally heterochromatic W chromosome. No chromosome differences were observed in the two species studied.

  16. Sex-biased gene expression on the avian Z chromosome: highly expressed genes show higher male-biased expression.

    PubMed

    Naurin, Sara; Hasselquist, Dennis; Bensch, Staffan; Hansson, Bengt

    2012-01-01

    Dosage compensation, the process whereby expression of sex-linked genes remains similar between sexes (despite heterogamety) and balanced with autosomal expression, was long believed to be essential. However, recent research has shown that several lineages, including birds, butterflies, monotremes and sticklebacks, lack chromosome-wide dosage compensation mechanisms and do not completely balance the expression of sex-linked and autosomal genes. To obtain further understanding of avian sex-biased gene expression, we studied Z-linked gene expression in the brain of two songbirds of different genera (zebra finch, Taeniopygia guttata, and common whitethroat, Sylvia communis) using microarray technology. In both species, the male-bias in gene expression was significantly higher for Z than for autosomes, although the ratio of Z-linked to autosomal expression (Z:A) was relatively close to one in both sexes (range: 0.89-1.01). Interestingly, the Z-linked male-bias in gene expression increased with expression level, and genes with low expression showed the lowest degree of sex-bias. These results support the view that the heterogametic females have up-regulated their single Z-linked homologues to a high extent when the W-chromosome degraded and thereby managed to largely balance their Z:A expression with the exception of highly expressed genes. The male-bias in highly expressed genes points towards male-driven selection on Z-linked loci, and this and other possible hypotheses are discussed. PMID:23056488

  17. BETA-ENDORPHIN LEVELS IN LONGTAILED AND PIGTAILED MACAQUES VARY BY ABNORMAL BEHAVIOR RATING AND SEX

    PubMed Central

    Crockett, Carolyn M.; Sackett, Gene P.; Sandman, Curt A.; Chicz-DeMet, Aleksandra; Bentson, Kathleen L.

    2007-01-01

    Frequent or severe abnormal behavior may be associated with the release of endorphins that positively reinforce the behavior with an opiate euphoria or analgesia. One line of research exploring this association involves the superhormone, proopiomelanocortin (POMC). The products of POMC appear to be dysregulated in some human subjects who exhibit self-injurious behavior (SIB). Macaque monkeys have POMC very similar to humans, and some laboratory macaques display SIB or frequent stereotypies. We investigated associations between plasma levels of three immunoreactive POMC fragments with possible opioid action and abnormal behavior ratings in macaques. In 58 adult male and female macaques (24 Macaca fascicularis and 34 M. nemestrina), plasma levels of intact beta-endorphin (?E) and the N-terminal fragment (BEN) were significantly higher in animals with higher levels of abnormal behavior. The C-terminal fragment (BEC) was significantly higher in males but unrelated to ratings of abnormal behavior. Levels of ACTH, cortisol, and (?E-ACTH)/?E dysregulation index were unrelated to abnormal behavior. None of the POMC products differed significantly by subjects' species, age, or weight. The finding that intact beta-endorphin is positively related to abnormal behavior in two species of macaque is consistent with some previous research on human subjects and nonprimates. The positive relation of the N-terminal fragment of ?E to abnormal behavior is a new finding. PMID:17719139

  18. Chromosomal Aberrations and Polymorphic Evaluation in Males with Primary Infertility from Indian Population

    PubMed Central

    Pokale, Yamini S.; Jadhav, Ajinkya M.; Gangane, Suresh D.

    2014-01-01

    Background and objectives: The chromosomal abnormalities are one of the important causes of male infertility. In view of the genetic risks for the next generation, the importance of careful evaluation of karyotype is essential. The objective of this study was to determine the frequency of chromosomal abnormalities in infertile men with primary infertility from Indian population. Materials and Methods: The 78 infertile men with primary infertility, out of which 26 men were azoospermic, 19 men were oligospermic, 4 men were asthenospermic and 29 men were oligoasthenospermic were studied. Karyoptying was performed on peripheral blood lymphocytes by using the Giemsa trypsin banding (GTG) banding technique. Additional data was collected from published studies in Indian population leading to a total of 1814 cases. Results: Chromosome analysis of 78 infertile males showed major chromosome abnormalities in 10.2%, with 6.4% in autosomal chromosome abnormalities and 3.8% in sex chromosome abnormalities. The incidence of major chromosome abnormalities in oligospermic males were 21% and azoospermic males were 15.4 %. Chromosomal polymorphic variants were identified to be 16.7%. Combining the data from other published studies identified 153/ 1814 (8.4%) infertile men of chromosomal abnormalities; with 10.8% in azoospermia, 7.3% in oligospermia and 7.3% in oligoasthenoteratospermic from India. Interpretation and Conclusion: The overall high prevalence of chromosomal abnormalities in infertile males suggests that the conventional chromosomal analysis is an important investigative tool for male infertility, especially prior to use of any assisted reproductive techniques. PMID:25478430

  19. B-chromosomes and male-biased sex ratio with paternal inheritance in the fairy shrimp Branchipus schaefferi (Crustacea, Anostraca).

    PubMed

    Beladjal, L; Vandekerckhove, T T M; Muyssen, B; Heyrman, J; de Caesemaeker, J; Mertens, J

    2002-05-01

    This study reports on male-biased sex ratios in west Mediterranean populations of the freshwater anostracan Branchipus schaefferi (Crustacea, Anostraca, Branchipodidae), in contrast to populations elsewhere. Crossing experiments over several generations indicate a clear paternal inheritance of the trait, possibly with a dosage effect. Various mechanisms which may underlie this phenomenon are discussed, the most plausible being the presence of one or more supernumerary ('B') chromosomes--as evidenced by karyological observations--interfering with sex determination and probably having an accumulation mechanism in male individuals. PMID:11986871

  20. Effect of sex chromosome complement on sodium appetite and Fos-immunoreactivity induced by sodium depletion.

    PubMed

    Dadam, Florencia M; Caeiro, Ximena E; Cisternas, Carla D; Macchione, Ana F; Cambiasso, María J; Vivas, Laura

    2014-02-01

    Previous studies indicate a sex chromosome complement (SCC) effect on the angiotensin II-sexually dimorphic hypertensive and bradycardic baroreflex responses. We sought to evaluate whether SCC may differentially modulate sexually dimorphic-induced sodium appetite and specific brain activity due to physiological stimulation of the rennin angiotensin system. For this purpose, we used the "four core genotype" mouse model, in which the effect of gonadal sex and SCC is dissociated, allowing comparisons of sexually dimorphic traits between XX and XY females as well as in XX and XY males. Gonadectomized mice were sodium depleted by furosemide (50 mg/kg) and low-sodium diet treatment; control groups were administered with vehicle and maintained on normal sodium diet. Twenty-one hours later, the mice were divided into two groups: one group was submitted to the water-2% NaCl choice intake test, while the other group was perfused and their brains subjected to the Fos-immunoreactivity (FOS-ir) procedure. Sodium depletion, regardless of SCC (XX or XY), induced a significantly lower sodium and water intake in females than in males, confirming the existence in mice of sexual dimorphism in sodium appetite and the organizational involvement of gonadal steroids. Moreover, our results demonstrate a SCC effect on induced brain FOS-ir, showing increased brain activity in XX-SCC mice at the paraventricular nucleus, nucleus of the solitary tract, and lateral parabrachial nucleus, as well as an XX-SCC augmented effect on sodium depletion-induced brain activity at two circumventricular organs, the subfornical organ and area postrema, nuclei closely involved in fluid and blood pressure homeostasis. PMID:24259464

  1. Chromosome mapping of retrotransposable elements Rex1 and Rex3 in Leporinus Spix, 1829 species (Characiformes: Anostomidae) and its relationships among heterochromatic segments and W sex chromosome

    PubMed Central

    Splendore de Borba, Rafael; Lourenço da Silva, Edson; Parise-Maltempi, Patrícia Pasquali

    2013-01-01

    The family Anostomidae is an interesting model for studies of repetitive elements, mainly because of the presence of high numbers of heterochromatic segments related to a peculiar system of female heterogamety, which is restricted to a few species of Leporinus genus. Thus, cytogenetic mapping of the retrotransposable elements Rex1, Rex3, and Rex6 was performed in six Leporinus species, to elucidate the genomic organization of this genus. The sequencing of the Rex1 and Rex3 elements detected different base pair compositions in these elements among species, whereas the Rex6 element was not identified in the genomes of these species. FISH analysis using Rex1 detected different distribution patterns, L. elongatus, L. macrocephalus, and L. obtusidens had clusters in the terminal regions, whereas the signals were dispersed throughout all of the chromosomes with some signals in the terminal position in other species. The Rex3 signals were found mainly in the terminal positions in all the chromosomes of all species. The W chromosomes of L. elongatus, L. macrocephalus, and L. obtusidens contained the Rex1 and Rex3 signal in an interstitial position. These results suggest the emergence of different activity levels for these elements during the evolution of the species analyzed. Despite the conserved karyotype macrostructure species Leporinus often discussed, our results show some variation in hybridization patterns, particularly between the species with specific patterns in their sex chromosomes and species without this differentiated system. PMID:24404417

  2. Site-specific accumulation of a LINE-like retrotransposon in a sex chromosome of the dioecious plant Cannabis sativa

    Microsoft Academic Search

    Koichi Sakamoto; Nobuko Ohmido; Kiichi Fukui; Hiroshi Kamada; Shinobu Satoh

    2000-01-01

    Male-associated DNA sequences were analysed in hemp (Cannabis sativa L.), a dioecious plant with heteromorphic sex chromosomes. A male-associated DNA sequence in C. sativa (MADC1) and its flanking sequence encoded a reverse transcriptase that was strongly homologous to those of LINE-like retrotransposons from various plants and other organisms, as well as another open reading frame (ORF). Fluorescence in situ hybridization (FISH) with

  3. Angiotensin II Type 2 Receptor- and Acetylcholine-Mediated Relaxation: Essential Contribution of Female Sex Hormones and Chromosomes.

    PubMed

    Pessôa, Bruno Sevá; Slump, Denise E; Ibrahimi, Khatera; Grefhorst, Aldo; van Veghel, Richard; Garrelds, Ingrid M; Roks, Anton J M; Kushner, Steven A; Danser, A H Jan; van Esch, Joep H M

    2015-08-01

    Angiotensin-induced vasodilation, involving type 2 receptor (AT2R)-induced generation of nitric oxide (NO; by endothelial NO synthase) and endothelium-derived hyperpolarizing factors, may be limited to women. To distinguish the contribution of female sex hormones and chromosomes to AT2R function and endothelium-derived hyperpolarizing factor-mediated vasodilation, we made use of the four-core genotype model, where the testis-determining Sry gene has been deleted (Y(-)) from the Y chromosome, allowing XY(-) mice to develop a female gonadal phenotype. Simultaneously, by incorporating the Sry gene onto an autosome, XY(-)Sry and XXSry transgenic mice develop into gonadal male mice. Four-core genotype mice underwent a sham or gonadectomy (GDX) operation, and after 8 weeks, iliac arteries were collected to assess vascular function. XY(-)Sry male mice responded more strongly to angiotensin than XX female mice, and the AT2R antagonist PD123319 revealed that this was because of a dilator AT2R-mediated effect occurring exclusively in XX female mice. The latter could not be demonstrated in XXSry male and XY(-) female mice nor in XX female mice after GDX, suggesting that it depends on both sex hormones and chromosomes. Indeed, treating C57bl/6 GDX male mice with estrogen could not restore angiotensin-mediated, AT2R-dependent relaxation. To block acetylcholine-induced relaxation of iliac arteries obtained from four-core genotype XX mice, both endothelial NO synthase and endothelium-derived hyperpolarizing factor inhibition were required, whereas in four-core genotype XY animals, endothelial NO synthase inhibition alone was sufficient. These findings were independent of gonadal sex and unaltered after GDX. In conclusion, AT2R-induced relaxation requires both estrogen and the XX chromosome sex complement, whereas only the latter is required for endothelium-derived hyperpolarizing factors. PMID:26056343

  4. Origin of the X1X1X2X2/X1X2Y sex chromosome system of Harttia punctata (Siluriformes, Loricariidae) inferred from chromosome painting and FISH with ribosomal DNA markers.

    PubMed

    Blanco, Daniel Rodrigues; Vicari, Marcelo Ricardo; Lui, Roberto Laridondo; Artoni, Roberto Ferreira; de Almeida, Mara Cristina; Traldi, Josiane Baccarin; Margarido, Vladimir Pavan; Moreira-Filho, Orlando

    2014-04-01

    Harttia is a genus in the subfamily Loricariinae that accommodates fishes popularly known as armored catfishes. They show extensive karyotypic diversity regarding interspecific numerical/structural variation of the karyotypes, with the presence of the XX/XY1Y2 multiple sex chromosome system, as found in H. carvalhoi. In this context, this study aimed to characterize Harttia punctata chromosomally, for the first time, and to infer the rearrangements that originated the X1X1X2X2/X1X2Y multiple sex chromosome system present in this species. The data obtained in this study, with classical (Giemsa, C-banding and AgNORs) and molecular methodologies (fluorescence in situ hybridization) and chromosome microdissection, indicated that a translocation between distinct acrocentric chromosomes bearing rRNA genes, accompanied by deletions in both chromosomes, might have originated the neo-Y chromosome in this species. The data also suggest that the multiple sex chromosome systems present in H. carvalhoi and H. punctata had an independent origin, evidencing the recurrence of chromosome alterations in species from this genus. PMID:24577679

  5. Extension, single-locus conversion and physical mapping of sex chromosome sequences identify the Z microchromosome and pseudo-autosomal region in a dragon lizard, Pogona vitticeps.

    PubMed

    Quinn, A E; Ezaz, T; Sarre, S D; Graves, Ja Marshall; Georges, A

    2010-04-01

    Distribution of temperature-dependent sex determination (TSD) and genotypic sex determination (GSD) across the phylogeny of dragon lizards implies multiple independent origins of at least one, and probably both, modes of sex determination. Female Pogona vitticeps are the heterogametic sex, but ZZ individuals reverse to a female phenotype at high incubation temperatures. We used reiterated genome walking to extend Z and W chromosome-linked amplified fragment length polymorphism (AFLP) markers, and fluorescence in situ hybridization for physical mapping. One extended fragment hybridized to both W and Z microchromosomes, identifying the Z microchromosome for the first time, and a second hybridized to the centromere of all microchromosomes. W-linked sequences were converted to a single-locus PCR sexing assay. P. vitticeps sex chromosome sequences also shared homology with several other Australian dragons. Further physical mapping and isolation of sex-specific bacterial artificial chromosome clones will provide insight into the evolution of sex determination and sex chromosomes in GSD and TSD dragon lizards. PMID:19812616

  6. Impact of Additional Cytogenetic Abnormalities in Adults with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation.

    PubMed

    Aldoss, Ibrahim; Stiller, Tracey; Cao, Thai M; Palmer, Joycelynne M; Thomas, Sandra H; Forman, Stephen J; Pullarkat, Vinod

    2015-07-01

    The occurrence of additional cytogenetic abnormalities (ACAs) is common in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) but is of unknown significance in the tyrosine kinase inhibitor (TKI) era. We retrospectively analyzed data from a consecutive case series of adults with Ph+ ALL who had undergone allogeneic hematopoietic cell transplantation (alloHCT) at City of Hope between 2003 and 2014. Among 130 adults with Ph+ ALL who had TKI therapy before alloHCT, 78 patients had available data on conventional cytogenetics at diagnosis and were eligible for outcomes analysis. ACAs were observed in 41 patients (53%). There were no statistically significant differences in median age, median initial WBC count, post-HCT TKI maintenance, or disease status at the time of transplant between the Ph-only and ACA cohorts; however, the Ph-only cohort had a higher rate of minimal residual disease positivity at the time of HCT. Three-year leukemia-free survival (79.8% versus 39.5%, P = .01) and 3-year overall survival (83% versus 45.6%, P = .02) were superior in the Ph-only cohort compared with the ACA cohort, respectively. Monosomy 7 was the most common additional aberration observed in our ACA cohort (n = 12). Thus, when TKI therapy and alloHCT are used as part of adult Ph+ ALL therapy, the presence of ACAs appears to have a significant deleterious effect on outcomes post-HCT. PMID:25842050

  7. Low rates of X-Y recombination, not turnovers, account for homomorphic sex chromosomes in several diploid species of Palearctic green toads (Bufo viridis subgroup).

    PubMed

    Stöck, M; Savary, R; Betto-Colliard, C; Biollay, S; Jourdan-Pineau, H; Perrin, N

    2013-03-01

    Contrasting with birds and mammals, most ectothermic vertebrates present homomorphic sex chromosomes, which might be due either to a high turnover rate or to occasional X-Y recombination. We tested these two hypotheses in a group of Palearctic green toads that diverged some 3.3 million years ago. Using sibship analyses of sex-linked markers, we show that all four species investigated share the same pair of sex chromosomes and a pattern of male heterogamety with drastically reduced X-Y recombination in males. Phylogenetic analyses of sex-linked sequences show that X and Y alleles cluster by species, not by gametolog. We conclude that X-Y homomorphy and fine-scale sequence similarity in these species do not stem from recent sex-chromosome turnovers, but from occasional X-Y recombination. PMID:23316809

  8. Contrasting Patterns of Transposable Element and Satellite Distribution on Sex Chromosomes (XY1Y2) in the Dioecious Plant Rumex acetosa

    PubMed Central

    Steflova, Pavlina; Tokan, Viktor; Vogel, Ivan; Lexa, Matej; Macas, Jiri; Novak, Petr; Hobza, Roman; Vyskot, Boris; Kejnovsky, Eduard

    2013-01-01

    Rumex acetosa is a dioecious plant with the XY1Y2 sex chromosome system. Both Y chromosomes are heterochromatic and are thought to be degenerated. We performed low-pass 454 sequencing and similarity-based clustering of male and female genomic 454 reads to identify and characterize major groups of R. acetosa repetitive DNA. We found that Copia and Gypsy retrotransposons dominated, followed by DNA transposons and nonlong terminal repeat retrotransposons. CRM and Tat/Ogre retrotransposons dominated the Gypsy superfamily, whereas Maximus/Sireviruses were most abundant among Copia retrotransposons. Only one Gypsy subfamily had accumulated on Y1 and Y2 chromosomes, whereas many retrotransposons were ubiquitous on autosomes and the X chromosome, but absent on Y1 and Y2 chromosomes, and others were depleted from the X chromosome. One group of CRM Gypsy was specifically localized to centromeres. We also found that majority of previously described satellites (RAYSI, RAYSII, RAYSIII, and RAE180) are accumulated on the Y chromosomes where we identified Y chromosome-specific variant of RAE180. We discovered two novel satellites—RA160 satellite dominating on the X chromosome and RA690 localized mostly on the Y1 chromosome. The expression pattern obtained from Illumina RNA sequencing showed that the expression of transposable elements is similar in leaves of both sexes and that satellites are also expressed. Contrasting patterns of transposable elements (TEs) and satellite localization on sex chromosomes in R. acetosa, where not only accumulation but also depletion of repetitive DNA was observed, suggest that a plethora of evolutionary processes can shape sex chromosomes. PMID:23542206

  9. Contrasting patterns of transposable element and satellite distribution on sex chromosomes (XY1Y2) in the dioecious plant Rumex acetosa.

    PubMed

    Steflova, Pavlina; Tokan, Viktor; Vogel, Ivan; Lexa, Matej; Macas, Jiri; Novak, Petr; Hobza, Roman; Vyskot, Boris; Kejnovsky, Eduard

    2013-01-01

    Rumex acetosa is a dioecious plant with the XY1Y2 sex chromosome system. Both Y chromosomes are heterochromatic and are thought to be degenerated. We performed low-pass 454 sequencing and similarity-based clustering of male and female genomic 454 reads to identify and characterize major groups of R. acetosa repetitive DNA. We found that Copia and Gypsy retrotransposons dominated, followed by DNA transposons and nonlong terminal repeat retrotransposons. CRM and Tat/Ogre retrotransposons dominated the Gypsy superfamily, whereas Maximus/Sireviruses were most abundant among Copia retrotransposons. Only one Gypsy subfamily had accumulated on Y1 and Y2 chromosomes, whereas many retrotransposons were ubiquitous on autosomes and the X chromosome, but absent on Y1 and Y2 chromosomes, and others were depleted from the X chromosome. One group of CRM Gypsy was specifically localized to centromeres. We also found that majority of previously described satellites (RAYSI, RAYSII, RAYSIII, and RAE180) are accumulated on the Y chromosomes where we identified Y chromosome-specific variant of RAE180. We discovered two novel satellites-RA160 satellite dominating on the X chromosome and RA690 localized mostly on the Y1 chromosome. The expression pattern obtained from Illumina RNA sequencing showed that the expression of transposable elements is similar in leaves of both sexes and that satellites are also expressed. Contrasting patterns of transposable elements (TEs) and satellite localization on sex chromosomes in R. acetosa, where not only accumulation but also depletion of repetitive DNA was observed, suggest that a plethora of evolutionary processes can shape sex chromosomes. PMID:23542206

  10. Presence of XIST specific sequences and apparent failure of X dosage compensation by inactivation in a patient with a severe Turner phenotype and mosaicism for X chromosome abnormalities

    SciTech Connect

    Bent-Williams, A.H.; Felton, S.M.; Driscoll, D.J. [Univ. of Florida, Gainesville, FL (United States)] [and others

    1994-09-01

    An XIST FISH analysis and a late replication chromosome study was performed for a 10 year old female with Turner stigmata, mental retardation, multiple congenital anomalies and a cytogenetic mosaicism of 45,X,inv(9)(p11q13)/46,X,del(X)(q22),inv(9)(p11q13)/46,X,+mar,inv(9)(p11q13). The X chromosomes from a cell line in which one was deleted for the distal long arm segment (breakpoint of Xq22), observed in 6% of metaphase cells from peripheral blood and 23.3% of metaphase cells from skin fibroblasts, did not demonstrate an asynchronous or differential staining pattern by BrDU techniques. However, both the normal X chromosome and the deleted X chromosome were demonstrated to contain XIST specific sequences by FISH analysis. A very small marker chromosome, observed in 6% of metaphase cells from peripheral blood and 3.3% of metaphase cells from skin fibroblasts, appeared to consist exclusively of X chromosome alpha satellite centromeric material (DXZ1). This finding was consistent with the morphology of the marker chromosome as observed by conventional G-banding. Due to its small size and low level frequency, analysis by late replication BrDU techniques was not possible. The predominate cell line containing a signal X chromosome was observed in 88% of metaphase cells from peripheral blood and 73.3% of metaphase cells from skin fibroblasts. This case is significant because: (1) it represents another case of an X chromosome abnormality in which XIST is apparently present but not expressed; and (2) the more severe phenotype expressed is probably attributable to the failure of X gene dosage compensation by inactivation.

  11. Myelodysplastic Syndrome with 6q Deletion as the Sole Chromosome Abnormality in an Iranian Patient: A Case Report with Review of Literature

    PubMed Central

    Ferdowsi, Shirin; Shirkoohi, Reza; Toogeh, Gholamreza

    2013-01-01

    Abstract Background: The myelodysplastic syndrome (MDS) is a highly heterogenous disorder and karyotype analysis is helpful for diagnostic and prognostic estimation. Deletion in long arm chromosome 6 (6q del) as a sole abnormality is a rare event in MDS. This is the first case report of del (6q) as the only observed diagnostic change in Iran. We also reviewed the literature of this cytogenetic lesion.

  12. Abnormalities of the ETV6 gene occur in the majority of patients with aberrations of the short arm of chromosome 12: a combined PCR and Southern blotting analysis

    Microsoft Academic Search

    HE O’Connor; TA Butler; R Clark; S Swanton; CJ Harrison; LM Secker-Walker; L Foroni

    1998-01-01

    Involvement of the ETV6 gene, located at 12p13, has been investigated in 20 patients with an abnormality of the short arm of chromosome 12 (abn 12p) detected cytogenetically. Patients in the study had c\\/pre-B acute lymphoblastic leukemia (ALL) (nine children and three adults), T-ALL (three adults), acute myeloid leukemia (AML) (two adults), biphenotypic acute leukemia (Bip-L) (one adult), myelodysplasia (MDS)

  13. Age-specific incidences of chromosome abnormalities at the second trimester amniocentesis for Japanese mothers aged 35 and older: collaborative study of 5484 cases

    Microsoft Academic Search

    Nobuo Yaegashi; Masato Senoo; Shigeki Uehara; Hisako Suzuki; Tohru Maeda; Keiya Fujimori; Fumiki Hirahara; Akira Yajima

    1998-01-01

    The aim of this study was to calculate the expected incidences of chromosome abnormalities found at amniocentesis in Japanese\\u000a women aged 35 and older. From four clinics in Japan, we gathered genetic amniocentesis data on 5484 pregnant women at risk\\u000a only due to their advanced age, 35 years and older. We analyzed the data using the logistic regression model. Of

  14. Sex-dependent mechanisms for expansions and contractions of the CAG repeat on affected Huntington disease chromosomes

    SciTech Connect

    Kremer, B.; Theilmann, J.; Spence, N. [Univ. of British Columbia, Vancouver (Canada)] [and others

    1995-08-01

    A total of 254 affected parent-child pairs with Huntington disease (HD) and 440 parent-child pairs with CAG size in the normal range were assessed to determine the nature and frequency of intergenerational CAG changes in the HD gene. Intergenerational CAG changes are extremely rare (3/440 [0.68%]) on normal chromosomes. In contrast, on HD chromosomes, changes in CAG size occur in {approximately}70% of meioses on HD chromosomes, with expansions accounting for 73% of these changes. These intergenerational CAG changes make a significant but minor contribution to changes in age at onset (r{sup 2}=.19). The size of the CAG repeat influenced larger intergenerational expansions (>7 CAG repeats), but the likelihood of smaller expansions or contractions was not influenced by CAG size. Large expansions (>7 CAG repeats) occur almost exclusively through paternal transmission (0.96%; P<10{sub -7}), while offspring of affected mothers are more likely to show no change (P=.01) or contractions in CAG size (P=.002). This study demonstrates that sex of the transmitting parent is the major determinant for CAG intergenerational changes in the HD gene. Similar paternal sex effects are seen in the evolution of new mutations for HD from intermediate alleles and for large expansions on affected chromosomes. Affected mothers almost never transmit a significantly expanded CAG repeat, despite the fact that many have similar large-sized alleles, compared with affected fathers. The sex-dependent effects of major expansion and contractions of the CAG repeat in the HD gene implicate different effects of gametogenesis, in males versus females, on intergenerational CAG repeat stability. 22 refs., 4 figs., 3 tabs.

  15. A duplicated copy of DMRT1 in the sex-determining region of the Y chromosome of the medaka, Oryzias latipes

    Microsoft Academic Search

    Indrajit Nanda; Mariko Kondo; Ute Hornung; Shuichi Asakawa; Christoph Winkler; Atsushi Shimizu; Zhihong Shan; Thomas Haaf; Nobuyoshi Shimizu; Akihiro Shima; Michael Schmid; Manfred Schartl

    2002-01-01

    The genes that determine the development of the male or female sex are known in Caenorhabditis elegans, Drosophila, and most mammals. In many other organisms the existence of sex-determining factors has been shown by genetic evidence but the genes are unknown. We have found that in the fish medaka the Y chromosome-specific region spans only about 280 kb. It contains

  16. "How should I tell my child?" Disclosing the diagnosis of sex chromosome aneuploidies.

    PubMed

    Dennis, Anna; Howell, Susan; Cordeiro, Lisa; Tartaglia, Nicole

    2015-02-01

    To date, the disclosure of a sex chromosome aneuploidy (SCA) diagnosis to an affected individual has not been explored. This study aimed to assess the timing and content revealed to an affected child by his or her parent(s), resources accessed in preparation, parental feelings of preparedness, common parental concerns, and recommendations for disclosure approaches. Two online surveys were created: 1) for parents of a child with a diagnosis and 2) for individuals with a diagnosis. One-hundred thirty-nine parent surveys (XXY n?=?68, XXX n?=?21, XYY n?=?9, other SCAs n?=?41) and 67 individual surveys (XXY n?=?58, XXX n?=?9) were analyzed. Parents most frequently discussed the topics of learning disabilities (47 %) and genetics (45 %) with their child during the initial disclosure. A significantly greater proportion of parent respondents reported feeling prepared vs. unprepared for disclosure, regardless of their child's diagnosis (z-test of proportions, all p's?

  17. Sex chromosome trisomies in Europe: prevalence, prenatal detection and outcome of pregnancy.

    PubMed

    Boyd, Patricia Anne; Loane, Maria; Garne, Ester; Khoshnood, Babak; Dolk, Helen

    2011-02-01

    This study aims to assess prevalence and pregnancy outcome for sex chromosome trisomies (SCTs) diagnosed prenatally or in the first year of life. Data held by the European Surveillance of Congenital Anomalies (EUROCAT) database on SCT cases delivered 2000-2005 from 19 population-based registries in 11 European countries covering 2.5 million births were analysed. Cases included were livebirths diagnosed to 1 year of age, fetal deaths from 20 weeks gestation and terminations of pregnancy for fetal anomaly (TOPFA). In all, 465 cases of SCT were diagnosed between 2000 and 2005, a prevalence of 1.88 per 10,000 births (95% CI 1.71-2.06). Prevalence of XXX, XXY and XYY were 0.54 (95% CI 0.46-0.64), 1.04 (95% CI 0.92-1.17) and 0.30 (95% CI 0.24-0.38), respectively. In all, 415 (89%) were prenatally diagnosed and 151 (36%) of these resulted in TOPFA. There was wide country variation in prevalence (0.19-5.36 per 1000), proportion prenatally diagnosed (50-100%) and proportion of prenatally diagnosed resulting in TOPFA (13-67%). Prevalence of prenatally diagnosed cases was higher in countries with high prenatal detection rates of Down syndrome. The EUROCAT prevalence rate for SCTs diagnosed prenatally or up to 1 year of age represents 12% of the prevalence expected from cytogenetic studies of newborn babies, as the majority of cases are never diagnosed or are diagnosed later in life. There is a wide variation between European countries in prevalence, prenatal detection and TOPFA proportions, related to differences in screening policies as well as organizational and cultural factors. PMID:20736977

  18. Meiotic abnormalities in metaphase I human spermatocytes from infertile males: frequencies, chromosomes involved, and the relationships with polymorphic karyotype and seminal parameters.

    PubMed

    Sarrate, Zaida; Vidal, Francesca; Blanco, Joan

    2014-01-01

    The aim of this study was to look in depth at the relationship between meiotic anomalies and male infertility, such as the determination of the chromosomes involved or the correlation with patient features. For this purpose, a total of 31 testicular tissue samples from individuals consulting for fertility problems were analyzed. Metaphase I cells were evaluated using a sequential methodology combining Leishman stained procedures and multiplex fluorescence in situ hybridization protocols. The number of chromosomal units and chiasmata count per bivalent were established and a hierarchical cluster analysis of the individuals was performed. The relationship of the seminogram and the karyotype over recombination were evaluated using Poisson regression models. Results obtained in this study show a significant percentage of infertile individuals with altered meiotic behavior, mostly specified as a reduction in chiasmata count in medium and large chromosomes, the presence of univalents, and the observation of tetraploid metaphases. Moreover, the number and the type of anomalies were found to be different between cells of the same individual, suggesting the coexistence of cell lines with normal meiotic behavior and cell lines with abnormalities. In addition, chromosomal abnormalities in metaphase I are significantly associated with oligozoospermia and/or polymorphic karyotype variants. PMID:25080930

  19. Meiotic abnormalities in metaphase I human spermatocytes from infertile males: frequencies, chromosomes involved, and relationship with polymorphic karyotype and seminal parameters

    PubMed Central

    Sarrate, Zaida; Vidal, Francesca; Blanco, Joan

    2014-01-01

    The aim of this study was to look in depth at the relationship between meiotic anomalies and male infertility, such as the determination of the chromosomes involved or the correlation with patient features. For this purpose, a total of 31 testicular tissue samples from individuals consulting for fertility problems were analyzed. Metaphase I cells were evaluated using a sequential methodology combining Leishman stained procedures and multiplex fluorescence in situ hybridization protocols. The number of chromosomal units and chiasmata count per bivalent were established and a hierarchical cluster analysis of the individuals was performed. The relationship of the seminogram and the karyotype over recombination were evaluated using Poisson regression models. Results obtained in this study show a significant percentage of infertile individuals with altered meiotic behavior, mostly specified as a reduction in chiasmata count in medium and large chromosomes, the presence of univalents, and the observation of tetraploid metaphases. Moreover, the number and the type of anomalies were found to be different between cells of the same individual, suggesting the coexistence of cell lines with normal meiotic behavior and cell lines with abnormalities. In addition, chromosomal abnormalities in metaphase I are significantly associated with oligozoospermia and/or polymorphic karyotype variants. PMID:25080930

  20. Identification and molecular characterization of a small chromosome 10q duplication [dir dup (10) (q24.2-24.3)] inherited from a mother mosaic for the abnormality

    SciTech Connect

    Tonk, V.; Schneider, N.R.; Schultz, R.A. [Univ. of Texas Southwestern Medical Center at Dallas, TX (United States)] [and others

    1994-09-01

    Inheritance of a cytogenetic abnormality from a clinically normal parent who is mosaic for the anomaly is rare event, although recent data suggest that such events may be more frequent than originally thought. The identification of such cases can have important implications for genetic counseling and can offer valuable resources for the mapping and analysis of genes involved in human disease and development. We describe a family in which two siblings exhibited developmental delay and very specific neurological abnormalities which included normal muscle mass but reduced muscle tone and mild muscle weakness. Cytogenetic evaluation revealed that both children had inherited a tandem duplication of a small portion of the long arm of chromosome 10 [dir dup (10) (q24.2-24.3)]. The clinically normal mother was found to be mosaic for the duplication which was identified in only two of the twenty metaphases examined. Fluorescence in situ hybridization approaches, including total chromosome painting and the use of previously characterized regional-specific cosmid probes, were used to confirm and characterize the chromosome 10q origin of the duplicated material. This represents the smallest confirmed duplication of distal chromosome 10q reported to date.

  1. DNA replication in the sex chromosomes of the pronghorn and the Rocky Mountain goat

    Microsoft Academic Search

    A. Dain

    1977-01-01

    The X chromosome of the male pronghorn (Antilocapra americana) is larger than the “original” type and carries a large segment of late-labelling chromatin. The Y chromosome has a late-labelling segment that appears to duplicate synchronously with that of the X. Both chromosomes have segments that label throughout the period of observation; that of the X is about 4.7 % of

  2. The sex-chromosome constitution and early postimplantation development of diandric triploid mouse embryos

    Microsoft Academic Search

    M. H. Kaufman; S. Speirs; K. K. H. Lee

    1989-01-01

    Diandric triploid mouse embryos were produced by standard micromanipulatory techniques, using eggs isolated from female mice with a normal chromosome constitution that had been mated to homozygous Rb(1.3)lBnr males (which carry a large metacentric “marker” chromosome, viz., a Robertsonian translocation involving chromosomes 1 and 3). The tripronucleate embryos were transferred to the oviducts of pseudopregnant mice, which were subsequently autopsied

  3. Potential use of buccal smears for rapid diagnosis of autosomal trisomy or chromosomal sex in newborn infants using DNA probes

    SciTech Connect

    Harris, C.; Clark, K.; Lazarski, K. [Univ. of Wisconsin, Madison, WI (United States); Wilkerson, C. [Univ. of Wisconsin Medical School, Madison, WI (United States); Meisner, L. [Univ. of Wisconsin, Madison, WI (United States)]|[Univ. of Wisconsin Medical School, Madison, WI (United States)

    1994-12-01

    Buccal smears from 3 women and 1 man were probed with alpha satellite DNA probes for chromosomes 8, 18, X, and Y. Buccal smears were also collected from an adolescent phenotypic female with uterine agenesis, as well as from newborn infants with suspected trisomy 18 and trisomy 21. The clinical cases were confirmed with conventional cytogenetic studies of peripheral lymphocytes. Overall probe efficiency at detecting expected chromosome number in interphase cells was found to be 71% {+-} 6.8%. Higher than expected n-1 signal numbers may be due to karyopyknotic intermediate epithelial cells present in all collected samples. Overall probe efficiency was found to be consistent using alpha satellite and cosmid probes, both of which accurately reflected the modal copy number of the target chromosomes. False trisomy was less than 1%. This study suggests DNA probes can be used in buccal smears for rapid diagnosis of trisomies and chromosomal sex in newborns, but because of high rates of false hydropoploid signals, probed buccal smear specimens may not be accurate at diagnosing mosaicism. 9 refs., 2 figs., 1 tab.

  4. Age-associated micronuclei, kinetochores and sex chromosome loss in men

    SciTech Connect

    Nath, J.; Hando, J. [West Virginia Univ., Morgantown, WV (United States); Tucker, J.D. [Lawrence Livermore National Laboratory, CA (United States)

    1995-11-01

    Studies on aneuploidy have shown a significant increase in the loss of chromosomes in both males and females with age and also a significant increase in micronucleus formation in lymphocytes with age. This study attempted (1) to ascertain whether the age-associated increase in Y chromosome loss and micronucleus formation are related. (2) to determine whether there is a correlation between Y chromosome-negative metaphase cells and Y chromosome-positive micronuclei from the same donors, and (3) to determine the relationships among the kinetochore status of micronuclei, Y chromosome-positive micronuclei, and age. Blood samples were obtained from thirty-five healthy males ranging in age from 22 to 79 years, and from the umbilical cords of eighteen newborn males. Two thousand binucleated cells were scored per sample. The kinetochore status of each micronucleus was recorded. Slides were then hybridized with the Y chromosome specific probe pHY10, labeled with biotinylated dUTP, and visualized with fluorescein conjugated avidin. All micronucleated cells were relocated and scored as Y+ or Y- depending on their Y probe status. A total of 303 micronuclei were scored, of which 41 (13.5%) contained the Y chromosome. ANOVA shows a significant increase in the number of Y chromosome-positive micronuclei with age (p<0.001). Of the 41 Y+ micronuclei 36 (87.8%) were kinetochore negative, suggesting a relationship between the absence of kinetochore function and micronucleus formation. Also, 500 metaphase spreads per sample were scored for the Y chromosome, showing an increase in Y-cells with age (p<0.001). A correlation analysis between Y chromosome-positive micronuclei and Y chromosome-negative metaphase cells resulted in a correlation coefficient of 0.71 (p.005).

  5. Sex-linked dominant

    MedlinePLUS

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... type of chromosome that is affected (autosomal or sex chromosome). It also depends on whether the trait ...

  6. Maternal serum free beta-hCG and PAPP-A in fetal sex chromosome defects in the first trimester.

    PubMed

    Spencer, K; Tul, N; Nicolaides, K H

    2000-05-01

    We have studied maternal serum free beta-hCG and PAPP-A, and fetal nuchal translucency (NT) in a series of 46 cases of fetal Turner's syndrome, 13 cases of other sex chromosomal anomalies and compared these with 947 control pregnancies in the first trimester. In cases of Turner's syndrome (45,X) the median fetal NT was significantly higher than in controls (4.76 MoM), the median PAPP-A was significantly lower (0.49 MoM), whilst the free beta-hCG was not significantly different (1.11 MoM). For NT, 93% (43/46) of cases were equal to or greater than the 95th centile of controls, for PAPP-A 35% (16/46) of cases were less than or equal to the 5th centile of controls and for free beta-hCG 15% (7/46) of cases were equal to or greater than the 95th centile of controls. For other sex chromosomal anomalies (47XXX, XXY, XYY) the median NT was increased (2.07 MoM) whilst PAPP-A was not significantly decreased (0.88 MoM) and free beta-hCG was not significantly different (1.07 MoM) from controls. Using a previously derived multivariate risk algorithm for trisomy 21, incorporating NT, PAPP-A, free beta-hCG and maternal age, 96% of the Turner's cases and 62% of the other sex chromosomal anomalies would have been identified. PMID:10820406

  7. Slcyt, a newly identified sex-linked gene, has recently moved onto the X chromosome in Silene latifolia (Caryophyllaceae).

    PubMed

    Kaiser, Vera B; Bergero, Roberta; Charlesworth, Deborah

    2009-10-01

    The sex chromosomes of the plant species Silene latifolia (white campion) are very young (only 5-10 My old), and all 11 X-linked genes so far described have Y-linked homologues. Theory predicts that X chromosomes should accumulate a nonrandom set of genes. However, little is known about the importance of gene movements between the X and the autosomes in plants, or in any very young sex chromosome system. Here, we isolate from cDNA a new gene, Slcyt, on the S. latifolia X, which encodes a cytochrome B protein. We genetically mapped SlCyt and found that it is located approximately 1 cM from the pseudoautosomal region. Genes in this region of the X chromosome have low divergence values from their homologous Y-linked genes, indicating that the X only recently stopped recombining with the Y. Genetic mapping in Silene vulgaris suggests that Slcyt originally belonged to a different linkage group from that of the other S. latifolia X-linked genes. Silene latifolia has no Y-linked homologue of Slcyt, and also no autosomal paralogues seem to exist. Slcyt moved from an autosome to the X very recently, as the Cyt gene is also X linked in Silene dioica, the sister species to S. latifolia, but is probably autosomal in Silene diclinis, implying that a translocation to the X probably occurred after the split between S. diclinis and S. latifolia/S. dioica. Diversity at Slcyt is extremely low (pi(syn) = 0.16%), and we find an excess of high frequency-derived variants and a negative Tajima's D, suggesting that the translocation was driven by selection. PMID:19587127

  8. Estimates of sperm sex chromosome disomy and diploidy rates in a 47,XXY\\/46,XY mosaic Klinefelter patient

    Microsoft Academic Search

    Alvin Soon Tiong Lim; Yang Fong; Su Ling Yu

    1999-01-01

    A 47,XXY\\/46,XY male was investigated for the incidence of aneuploidy in sperm sex chromosomes using a three-colour X\\/Y\\/18\\u000a fluorescence in situ hybridisation (FISH) protocol. A total of 1701 sperm nuclei were analysed. The ratio of X-bearing to\\u000a Y-bearing sperm did not differ from the expected 1?:?1 ratio although there were more 23,Y sperm than 23,X sperm (844 vs 795).\\u000a There

  9. Multicolor banding detects a complex three chromosome, seven breakpoint unbalanced rearrangement in an ICSI-derived fetus with multiple abnormalities.

    PubMed

    Seller, Mary J; Bint, Susan; Kavalier, Fred; Brown, Richard N; Ogilvie, Caroline Mackie

    2006-05-15

    We describe a fetus from an intracytoplasmic sperm injection (ICSI) pregnancy with severe facial clefts, receding jaw, preauricular skin tags, postaxial hexadactyly, bi-lobed right lung, supernumerary cranial bone, and dilated lateral ventricles of the brain. Using a combination of G-banding, fluorescence in situ hybridization (FISH), whole chromosome paints (WCPs), subtelomere probes, and multicolor banding (MCB), the karyotype was found to include a de novo unbalanced highly complex chromosome rearrangement (hCCR) involving chromosomes 3, 12, and 15 with seven breakpoints, and including monosomy for two separate regions of chromosome 12. PMID:16596677

  10. Enzymatic amplification of a Y chromosome repeat in a single blastomere allows identification of the sex of preimplantation mouse embryos

    SciTech Connect

    Bradbury, M.W.; Isola, L.M.; Gordon, J.W. (Mount Sinai School of Medicine, New York, NY (USA))

    1990-06-01

    The polymerase chain reaction (PCR) technique has been adapted to identify the sex of preimplantation mouse embryos rapidly. PCR was used to amplify a specific repeated DNA sequence on the Y chromosome from a single isolated blastomere in under 12 hr. The remainder of the biopsied embryo was then transferred to a pseudopregnant female and carried to term. Using this technique, 72% of embryos can be classed as potentially either male or female. Transfers of such embryos have produced pregnancies with 8/8 fetuses (100%) being of the predicted sex. Variations of the technique have demonstrated certain limitations to the present procedure as well as indicated possible strategies for improvement of the assay. The PCR technique may have wide application in the genetic analysis of preimplantation embryos.

  11. A sex-linked SCAR marker in Bryonia dioica (Cucurbitaceae), a dioecious species with XY sex-determination and homomorphic sex chromosomes

    Microsoft Academic Search

    R. K. OYAMA; S. M. VOLZ; S. S. RENNER

    2008-01-01

    Genetic crosses between the dioecious Bryonia dioica (Cucurbitaceae) and the monoecious B. alba in 1903 provided the first clear evidence for Mendelian inheritance of dioecy and made B. dioica the first organism for which XY sex- determination was experimentally proven. Applying molecular tools to this system, we developed a sex-linked sequence-characterized amplified region (SCAR) marker for B. dioica and sequenced

  12. Sequencing of a patient with balanced chromosome abnormalities and neurodevelopmental disease identifies disruption of multiple high risk loci by structural variation.

    PubMed

    Blake, Jonathon; Riddell, Andrew; Theiss, Susanne; Gonzalez, Alexis Perez; Haase, Bettina; Jauch, Anna; Janssen, Johannes W G; Ibberson, David; Pavlinic, Dinko; Moog, Ute; Benes, Vladimir; Runz, Heiko

    2014-01-01

    Balanced chromosome abnormalities (BCAs) occur at a high frequency in healthy and diseased individuals, but cost-efficient strategies to identify BCAs and evaluate whether they contribute to a phenotype have not yet become widespread. Here we apply genome-wide mate-pair library sequencing to characterize structural variation in a patient with unclear neurodevelopmental disease (NDD) and complex de novo BCAs at the karyotype level. Nucleotide-level characterization of the clinically described BCA breakpoints revealed disruption of at least three NDD candidate genes (LINC00299, NUP205, PSMD14) that gave rise to abnormal mRNAs and could be assumed as disease-causing. However, unbiased genome-wide analysis of the sequencing data for cryptic structural variation was key to reveal an additional submicroscopic inversion that truncates the schizophrenia- and bipolar disorder-associated brain transcription factor ZNF804A as an equally likely NDD-driving gene. Deep sequencing of fluorescent-sorted wild-type and derivative chromosomes confirmed the clinically undetected BCA. Moreover, deep sequencing further validated a high accuracy of mate-pair library sequencing to detect structural variants larger than 10 kB, proposing that this approach is powerful for clinical-grade genome-wide structural variant detection. Our study supports previous evidence for a role of ZNF804A in NDD and highlights the need for a more comprehensive assessment of structural variation in karyotypically abnormal individuals and patients with neurocognitive disease to avoid diagnostic deception. PMID:24625750

  13. Sequencing of a Patient with Balanced Chromosome Abnormalities and Neurodevelopmental Disease Identifies Disruption of Multiple High Risk Loci by Structural Variation

    PubMed Central

    Blake, Jonathon; Riddell, Andrew; Theiss, Susanne; Gonzalez, Alexis Perez; Haase, Bettina; Jauch, Anna; Janssen, Johannes W. G.; Ibberson, David; Pavlinic, Dinko; Moog, Ute; Benes, Vladimir; Runz, Heiko

    2014-01-01

    Balanced chromosome abnormalities (BCAs) occur at a high frequency in healthy and diseased individuals, but cost-efficient strategies to identify BCAs and evaluate whether they contribute to a phenotype have not yet become widespread. Here we apply genome-wide mate-pair library sequencing to characterize structural variation in a patient with unclear neurodevelopmental disease (NDD) and complex de novo BCAs at the karyotype level. Nucleotide-level characterization of the clinically described BCA breakpoints revealed disruption of at least three NDD candidate genes (LINC00299, NUP205, PSMD14) that gave rise to abnormal mRNAs and could be assumed as disease-causing. However, unbiased genome-wide analysis of the sequencing data for cryptic structural variation was key to reveal an additional submicroscopic inversion that truncates the schizophrenia- and bipolar disorder-associated brain transcription factor ZNF804A as an equally likely NDD-driving gene. Deep sequencing of fluorescent-sorted wild-type and derivative chromosomes confirmed the clinically undetected BCA. Moreover, deep sequencing further validated a high accuracy of mate-pair library sequencing to detect structural variants larger than 10 kB, proposing that this approach is powerful for clinical-grade genome-wide structural variant detection. Our study supports previous evidence for a role of ZNF804A in NDD and highlights the need for a more comprehensive assessment of structural variation in karyotypically abnormal individuals and patients with neurocognitive disease to avoid diagnostic deception. PMID:24625750

  14. B Chromosomes Have a Functional Effect on Female Sex Determination in Lake Victoria Cichlid Fishes

    Microsoft Academic Search

    Kohta Yoshida; Yohey Terai; Shinji Mizoiri; Mitsuto Aibara; Hidenori Nishihara; Masakatsu Watanabe; Asato Kuroiwa; Hirohisa Hirai; Yuriko Hirai; Yoichi Matsuda; Norihiro Okada

    2011-01-01

    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, we performed cytogenetic analysis in 11 cichlid species

  15. Sex Differences in the Cerebellum and Frontal Cortex: Roles of Estrogen Receptor Alpha and Sex Chromosome Genes

    Microsoft Academic Search

    Jean M. Abel; Diane M. Witt; Emilie F. Rissman

    2011-01-01

    Most neurobehavioral diseases are sexually dimorphic in their incidence, and sex differences in the brain may be key for understanding and treating these diseases. Calbindin (Calb) D28K is used as a biomarker for the well-studied sexually dimorphic nucleus, a hypothalamic structure that is larger in males than in females. In the current study weanling C56BL\\/6J mice were used to examine

  16. Sex chromosome pre-reduction in male meiosis of Lethocerus patruelis (Stĺl, 1854) (Heteroptera, Belostomatidae) with some notes on the distribution of the species

    PubMed Central

    Grozeva, Snejana; Kuznetsova, Valentina G.; Simov, Nikolay; Langourov, Mario; Dalakchieva, Svetla

    2013-01-01

    Abstract The karyotype and meiosis in males of giant water bug Lethocerus patruelis (Heteroptera: Belostomatidae: Lethocerinae) were studied using standard and fluorochrome (CMA3 and DAPI) staining of chromosomes. The species was shown to have 2n = 22A + 2m + XY where 2m are a pair of microchromosomes. NORs are located in X and Y chromosomes. Within Belostomatidae, Lethocerus patruelis is unique in showing sex chromosome pre-reduction in male meiosis, with the sex chromosomes undergoing reductional division at anaphase I and equational division at anaphase II. Cytogenetic data on the family Belostomatidae are summarized and compared. In addition, the structure of the male internal reproductive organs of Lethocerus patruelis is presented, the contemporary distribution of Lethocerus patruelis in Bulgaria and in the northern Aegean Islands is discussed, and the first information about the breeding and nymphal development of this species in Bulgaria is provided. PMID:24039515

  17. Inter- and intraspecies phylogenetic analyses reveal extensive X-Y gene conversion in the evolution of gametologous sequences of human sex chromosomes.

    PubMed

    Trombetta, Beniamino; Sellitto, Daniele; Scozzari, Rosaria; Cruciani, Fulvio

    2014-08-01

    It has long been believed that the male-specific region of the human Y chromosome (MSY) is genetically independent from the X chromosome. This idea has been recently dismissed due to the discovery that X-Y gametologous gene conversion may occur. However, the pervasiveness of this molecular process in the evolution of sex chromosomes has yet to be exhaustively analyzed. In this study, we explored how pervasive X-Y gene conversion has been during the evolution of the youngest stratum of the human sex chromosomes. By comparing about 0.5 Mb of human-chimpanzee gametologous sequences, we identified 19 regions in which extensive gene conversion has occurred. From our analysis, two major features of these emerged: 1) Several of them are evolutionarily conserved between the two species and 2) almost all of the 19 hotspots overlap with regions where X-Y crossing-over has been previously reported to be involved in sex reversal. Furthermore, in order to explore the dynamics of X-Y gametologous conversion in recent human evolution, we resequenced these 19 hotspots in 68 widely divergent Y haplogroups and used publicly available single nucleotide polymorphism data for the X chromosome. We found that at least ten hotspots are still active in humans. Hence, the results of the interspecific analysis are consistent with the hypothesis of widespread reticulate evolution within gametologous sequences in the differentiation of hominini sex chromosomes. In turn, intraspecific analysis demonstrates that X-Y gene conversion may modulate human sex-chromosome-sequence evolution to a greater extent than previously thought. PMID:24817545

  18. SRY and karyotypic status of one abnormal and two intersexual marsupials.

    PubMed

    Watson, C M; Johnston, P G; Rodger, K A; McKenzie, L M; O'Neill, R J; Cooper, D W

    1997-01-01

    An intersexual agile wallaby (Macropus agilis) with a penis, a pouch and four teats had a sex-chromosome constitution of XXY in lymphocytes and cultured fibroblasts; the sex-determining region Y (SRY) gene was present, consistent with the presence of a testis. An intersexual eastern grey kangaroo (Macropus giganteus) with a small empty scrotum and no penis, and an abnormal red kangaroo (Macropus rufus) with no penis, pouch or teats, both had XX sex-chromosome complements; the SRY gene was not present, consistent with testis absence. The agile wallaby and grey kangaroo described here provide further evidence that scrotal development in marsupials is independent of the Y chromosome. The cause of the abnormalities in the XX individuals cannot be determined until candidate genes are identified. These animals provide a basis for further genetic studies into marsupial intersexuality and sex differentiation. PMID:9208434

  19. Chromosomal abnormalities in Philadelphia chromosome-negative metaphases appearing during imatinib mesylate therapy in patients with newly diagnosed chronic myeloid leukemia in chronic phase

    Microsoft Academic Search

    Elias Jabbour; Hagop M. Kantarjian; Lynne V. Abruzzo; Susan O'Brien; Guillermo Garcia-Manero; Srdan Verstovsek; Jianqin Shan; Mary Beth Rios; Jorge Cortes

    2007-01-01

    The development of chromosomal abnor- malities (CAs) in the Philadelphia chromo- some (Ph)-negative metaphases during ima- tinib (IM) therapy in patients with newly diagnosed chronic myecloid leukemia (CML) has been reported only anecdotally. We as- sessed the frequency and significance of this phenomenon among 258 patients with newly diagnosed CML in chronic phase re- ceiving IM. After a median follow-up

  20. TWO SEX-CHROMOSOME-LINKED MICROSATELLITE LOCI SHOW GEOGRAPHIC VARIANCE AMONG NORTH AMERICAN OSTRINIA NUBILALIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A (GAAAAT)n repeat microsatellite was isolated from a partial Ostrinia nubilalis genomic library. Pedigree analysis indicated the marker was female specific, and referred to as Ostrinia nubilalis W-chromosome marker 1 (ONW1). Polymerase chain reaction (PCR) and DNA sequence analysis indicated that ...

  1. A sex-chromosome hybrid zone in the grasshopper Podisma pedestris (Orthoptera: Acrididae)

    Microsoft Academic Search

    Godfrey M Hewitt

    1975-01-01

    Podisma pedestris exists as both an XO and neoXY form in the Southern French Alps These chromosome types are shown to be contiguously allopatric and hybrid populations have been located in several places. Hybridisation appears to be occurring freely, but the hybrid zones are quite narrow. In several places the two distributions are separated by geographic barriers such as high

  2. A Pseudoautosomal Random Amplified Polymorphic DNA Marker for the Sex Chromosomes of Silene dioica

    Microsoft Academic Search

    Veronica S. Di Stilio; Richard V. Kesseli; David L. Mulcahy

    1998-01-01

    The segregation pattern of an 810-bp random amplified polymorphic DNA (RAPD) band in the F1 and backcross generations of a Silene dioica (L.) Clairv. family provides evidence that this molecular marker is located in the pseudoautosomal region (PAR) of the X and Y chromosomes. The marker was found through a combination of bulked segregant analysis (BSA) and RAPD techniques. Recombination

  3. Chromosomes and cancer cells

    Microsoft Academic Search

    Sarah L. Thompson; Duane A. Compton

    2011-01-01

    Two prominent features of cancer cells are abnormal numbers of chromosomes (aneuploidy) and large-scale structural rearrangements\\u000a of chromosomes. These chromosome aberrations are caused by genomic instabilities inherent to most cancers. Aneuploidy arises\\u000a through chromosomal instability (CIN) by the persistent loss and gain of whole chromosomes. Chromosomal rearrangements occur\\u000a through chromosome structure instability (CSI) as a consequence of improper repair of

  4. A gene mapping to the sex-determining region of the mouse Y chromosome is a member of a novel family of embryonically expressed genes

    Microsoft Academic Search

    John Gubbay; Jérôme Collignon; Peter Koopman; Blanche Capel; Androulla Economou; Andrea Münsterberg; Nigel Vivian; Peter Goodfellow; Robin Lovell-Badge

    1990-01-01

    A gene mapping to the sex-determining region of the mouse Y chromosome is deleted in a line of XY female mice mutant for Tdy, and is expressed at a stage during male gonadal development consistent with its having a role in testis determination. This gene is a member of a new family of at least five mouse genes, related by

  5. Dermatoglyphic findings in 54 tripleX females and a review of some general principles applying to the soles in sex chromosome aneuploidy

    Microsoft Academic Search

    P Saldańa-Garcia

    1975-01-01

    The dermatoglyphic findings from 54 females with XXX sex chromosomes are reported. Sole prints were available for study in 33 cases. Compared with female controls, an excess of radial loops and arches and a reduced mean for total finger ridge-count were the main peculiarities on the fingers. On the palms, the absence of pattern in areas I and II, and

  6. Chromosome banding studies in two patients with XXXXY syndrome.

    PubMed Central

    Levy, C L; Sparkes, R S; Carlson, H E

    1978-01-01

    In 2 adult male patients with 49 chromosomes, an XXXXY sex chromosome constitution was confirmed by trypsin-Giemsa banding sites. Clinical findings as well as fingerprint ridge counts were typical of the syndrome. Primary hypogonadism was documented by finding low serum testosterone and raised serum LH and FSH levels. Several radiological abnormalities, not previously described in this syndrome, were seen in 1 patient. Images PMID:568665

  7. Unbalanced chromosome 1 abnormalities leading to partial trisomy 1q in four infants with Down syndrome and acute megakaryocytic leukemia

    Microsoft Academic Search

    Maria Luiza Macedo Silva; Maria do Socorro Pombo-de-Oliveira; Susana C Raimondi; Hasmik Mkrtchyan; Eliana Abdelhay; Amanda Faria de Figueiredo; Mariana Tavares de Souza; Daniela Ribeiro Ney Garcia; Eliane Maria Soares de Ventura; Adriana Martins de Sousa; Thomas Liehr

    2009-01-01

    BACKGROUND: Children with Down syndrome (DS) have an increased risk of childhood acute leukemia, especially acute megakaryoblastic leukemia (AMKL) also called acute myeloid leukemia (AML) type M7. Here four yet unreported infants with such malignancies are reported. RESULTS: An unbalanced translocation involving chromosome 1 was identified by GTG banding in all cases. These were characterized in more detail by molecular

  8. Sex determination in dioecious Silene latifolia. Effects of the Y chromosome and the parasitic smut fungus (Ustilago violacea) on gene expression during flower development.

    PubMed Central

    Scutt, C P; Li, T; Robertson, S E; Willis, M E; Gilmartin, P M

    1997-01-01

    We have embarked on a molecular cloning approach to the investigation of sex determination in Silene latifolia Poiret, a dioecious plant species with morphologically distinguishable sex chromosomes. One of our key objectives was to define a range of genes that are up-regulated in male plants in response to Y chromosome sex-determination genes. Here we present the characterization of eight male-specific cDNA sequences and classify these according to their expression dynamics to provide a range of molecular markers for dioecious male flower development. Genetically female S. latifolia plants undergo a partial sex reversal in response to infection by the parasitic smut fungus Ustilago violacea. This phenomenon has been exploited in these studies; male-specific cDNAs have been further categorized as inducible or noninducible in female plants by smut fungus infection. Analysis of the organ-specific expression of male-specific probes in male and female flowers has also identified a gene that is regulated in a sex-specific manner in nonreproductive floral tissues common to both male and female plants. This observation provides, to our knowledge, the first molecular marker for dominant effect of the Y chromosome in nonreproductive floral organs. PMID:9232878

  9. Getting a Full Dose? Reconsidering Sex Chromosome Dosage Compensation in the Silkworm, Bombyx mori

    E-print Network

    Walters, James R.; Hardcastle, Thomas J.

    2011-04-20

    -wise analysis using the ML thresh- old and the PTL and VSN normalizations. Table 1 Summary of Microarray Analysis of Bombyx mori Male:Female Expression Ratios on the Z and Autosomes from Nine Different Tissues Gonad Head Integument Malpighian Tubules Ant... online). Mean and median M:F expression ratios from the two groups of chromosomes generally differ by only a few percentage points in somatic tissues. Even for head and integument, which show significant differences across all the different analyses...

  10. Mapping of sex-linked genes onto the genome sequence using various aberrations of the Z chromosome in Bombyx mori

    Microsoft Academic Search

    Tsuguru Fujii; Hiroaki Abe; Susumu Katsuma; Kazuei Mita; Toru Shimada

    2008-01-01

    Many strains of Bombyx mori carry chromosomal aberrations, and they are useful resources for integration between phenotypes and genomic sequences. We compared the molecular structures of three kinds of Z chromosomes, i.e., two strains with chromosome deletions and one strain with translocation involving the Z chromosome. Using polymerase chain reaction markers, we showed that: (1) the Z1 chromosome lacks more

  11. The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

    PubMed Central

    Metin, Banu; Findley, Keisha; Heitman, Joseph

    2010-01-01

    Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals. PMID:20502678

  12. The sex-linked region in Populus tremuloides Turesson 141 corresponds to a pericentromeric region of about two million base pairs on P. trichocarpa chromosome 19.

    PubMed

    Kersten, B; Pakull, B; Groppe, K; Lueneburg, J; Fladung, M

    2014-03-01

    In the dioecious genus Populus, sex determination has been located to chromosome 19. However, despite a high degree of genome collinearity, various Populus species seem to differ with regard to the location of the sex-determining region on the respective chromosome and the apparent heterogametic sex. In this study, the boundaries of the recombination-suppressed, sex-linked region of the male P. tremuloides clone Turesson 141 were localised by genetic mapping using new SNP and InDel markers. The respective region seems to be located in a pericentromeric position. The corresponding P. trichocarpa genome region spans about two million bp and comprises 65 gene loci, which were bioinformatically evaluated for their potential as candidate genes for sex determination. Three putative transcription factor genes and four genes that are potentially involved in flower development processes, e.g. meristem transition from the vegetative to the reproductive phase, were identified. Populus tremuloides sequence data of the sex-linked region is required for a final search for candidate genes. PMID:23710995

  13. Inference of sex-specific expansion patterns in human populations from Y-chromosome polymorphism.

    PubMed

    Aimé, Carla; Heyer, Evelyne; Austerlitz, Frédéric

    2015-06-01

    Studying the current distribution of genetic diversity in humans has important implications for our understanding of the history of our species. We analyzed a set of linked STR and SNP loci from the paternally inherited Y chromosome to infer the past demography of 55 African and Eurasian populations, using both the parametric and nonparametric coalescent-based methods implemented in the BEAST application. We inferred expansion events in most sedentary farmer populations, while we found constant effective population sizes for both nomadic hunter-gatherers and seminomadic herders. Our results differed, on several aspects, from previous results on mtDNA and autosomal markers. First, we found more recent expansion patterns in Eurasia than in Africa. This discrepancy, substantially stronger than the ones found with the other kind of markers, may result from a lower effective population size for men, which might have made male-transmitted markers more sensitive to the out-of-Africa bottleneck. Second, we found expansion signals only for sedentary farmers but not for nomadic herders in Central Asia, while these signals were found for both kind of populations in this area when using mtDNA or autosomal markers. Expansion signals in this area may result from spatial expansion processes and may have been erased for the Y chromosome among the herders because of restricted male gene flow. Am J Phys Anthropol 157:217-225, 2015. © 2015 Wiley Periodicals, Inc. PMID:25662940

  14. Current controversies in prenatal diagnosis 1: NIPT for chromosome abnormalities should be offered to women with low a priori risk.

    PubMed

    Van Lith, Jan M M; Faas, Brigitte H W; Bianchi, Diana W

    2015-01-01

    In its successful annual cycle of controversies and debates, the International Society of Prenatal Diagnosis and Therapy once again addressed non-invasive prenatal testing (NIPT) by following up on the 2013 controversy, 'Should non-invasive DNA testing be the standard screening test for Down syndrome in all pregnant women'? with the proposition, 'NIPT for chromosomel abnormalities should be offered to women with low a priori risk'. PMID:25393690

  15. Unique double de novo structural rearrangements for chromosome 11 with 46,XX,del(11)(q13q23)/46,XX,inv dup(11)(q13q23) in an infant with minor congenital abnormalities and delayed development

    SciTech Connect

    Tharapel, A.T.; Zhao, J.; Smith, M.E. [Univ. of Tennessee, Memphis, TN (United States)] [and others

    1994-09-01

    Reported here is a patient with two most unusual structural rearrangements, both involving chromosome 11. The first cell line showed an interstitial deletion of a chromosome 11 with a 46,XX,del(11)(q13q23) chromosome complement. In the second cell line, one of the chromosome 11s had a duplication for the exact region, (11)(q13q23), that was deleted in the first cell line. This duplication also appeared to be inverted with karyotype 46,XX,inv dup(11)(q13q23). Interestingly, chromosome analysis did not reveal a normal cell line and the two abnormal cell lines were present in a 1:1 ratio. Parental chromosome analyses showed normal karyotypes. The patient was referred for genetic evaluation because of developmental delay. Minor congenital anomalies presented on physical examination included: weight and height at or below the 5th percentile, microcephaly, downward slanting palpebral fissures, severe clinodactyly of one toe, bilateral short fifth fingers and a broad based gait. Results of the MRI and urine metabolic screen were normal. Two hypotheses are advanced to explain the origin of the abnormality. It is most likely that the abnormality arose as a postzygotic event at the very early zygotic division. During the first DNA synthesis after fertilization and before the zygotic division, DNA synthesis errors could result in two chromatids, one with a deletion and the other with a duplication. It is also possible that after the DNA synthesis prior to the first cell division, the chromatids of the same chromosome 11 for unknown reasons were involved in uneven double somatic crossing over events resulting in deleted and duplicated chromatids, respectively. The 1:1 cell ratio found in the patient and the apparent non-existence of a normal cell line further suggest that the origin of the abnormality was post-zygotic.

  16. Structural chromosome abnormalities, increased DNA strand breaks and DNA strand break repair deficiency in dermal fibroblasts from old female human donors

    PubMed Central

    Kalfalah, Faiza; Seggewiß, Sabine; Walter, Regina; Tigges, Julia; Moreno-Villanueva, María; Bürkle, Alexander; Ohse, Sebastian; Busch, Hauke; Boerries, Melanie; Hildebrandt, Barbara; Royer-Pokora, Brigitte; Boege, Fritz

    2015-01-01

    Dermal fibroblasts provide a paradigmatic model of cellular adaptation to long-term exogenous stress and ageing processes driven thereby. Here we addressed whether fibroblast ageing analysed ex vivo entails genome instability. Dermal fibroblasts from human female donors aged 20–67 years were studied in primary culture at low population doubling. Under these conditions, the incidence of replicative senescence and rates of age-correlated telomere shortening were insignificant. Genome-wide gene expression analysis revealed age-related impairment of mitosis, telomere and chromosome maintenance and induction of genes associated with DNA repair and non-homologous end-joining, most notably XRCC4 and ligase 4. We observed an age-correlated drop in proliferative capacity and age-correlated increases in heterochromatin marks, structural chromosome abnormalities (deletions, translocations and chromatid breaks), DNA strand breaks and histone H2AX-phosphorylation. In a third of the cells from old and middle-aged donors repair of X-ray induced DNA strand breaks was impaired despite up-regulation of DNA repair genes. The distinct phenotype of genome instability, increased heterochromatinisation and (in 30% of the cases futile) up-regulation of DNA repair genes was stably maintained over several cell passages indicating that it represents a feature of geroconversion that is distinct from cellular senescence, as it does not encompass a block of proliferation. PMID:25678531

  17. Pure Red Cell Aplasia in a Patient with Trrisomy X Chromosome Abnormality and Reactivated Epstein-Barr Virus Infection

    Microsoft Academic Search

    Masanori Daibata; Hisanori Machida; Yuiko Nemoto; Hirokuni Taguchi

    2003-01-01

    We describe a woman with a congenital chromosome anomaly, 47,XXX, who developed chronic pure red cell aplasia (PRCA).The patient\\u000a had serologic reactivity consistent with that of reactivated Epstein-Barr virus (EBV) infection, as judged by high titers\\u000a for anti-EBV viral capsid antigen (VCA) immunoglobulin G (IgG) and anti-early antigen (EA) IgG.Detection of EBV genome in\\u000a peripheral blood cells and cell-free serum

  18. A Locus Identified on Chromosome18P11.31 is Associated with Hippocampal Abnormalities in a Family with Mesial Temporal Lobe Epilepsy

    PubMed Central

    Maurer-Morelli, Cláudia V.; Secolin, Rodrigo; Morita, Márcia E.; Domingues, Romęnia R.; Marchesini, Rafael B.; Santos, Neide F.; Kobayashi, Eliane; Cendes, Fernando; Lopes-Cendes, Iscia

    2012-01-01

    We aimed to identify the region harboring a putative candidate gene associated with hippocampal abnormalities (HAb) in a family with mesial temporal lobe epilepsy (MTLE). Genome-wide scan was performed in one large kindred with MTLE using a total of 332 microsatellite markers at ?12?cM intervals. An additional 13 markers were genotyped in the candidate region. Phenotypic classes were defined according to the presence of hippocampal atrophy and/or hyperintense hippocampal T2 signal detected on magnetic resonance imaging. We identified a significant positive LOD score on chromosome 18p11.31 with a Zmax of 3.12 at D18S452. Multipoint LOD scores and haplotype analyses localized the candidate locus within a 6-cM interval flanked by D18S976 and D18S967. We present here evidence that HAb, which were previously related mainly to environmental risk factors, may be influenced by genetic predisposition. This finding may have major impact in the study of the mechanisms underlying abnormalities in mesial temporal lobe structures and their relationship with MTLE. PMID:23015801

  19. Human Chromosomes

    NSDL National Science Digital Library

    BEGIN:VCARD VERSION:2.1 FN:Access Excellence N:Excellence; Access REV:2005-03-12 END:VCARD

    2005-03-12

    Representation of the 23 paired chromosomes of the human male. Chromosome: a very long DNA molecule and associated proteins, that carry portions of the hereditary information of an organism. a. Structure of a chromosome (Typical metaphase chromosome): A chromosome is formed from a single DNA molecule that contains many genes. A chromosomal DNA molecule contains three specific nucleotide sequences which are required for replication: a DNA replication origin; a centromere to attach the DNA to the mitotic spindle.; a telomere located at each end of the linear chromosome. The DNA molecule is highly condensed. The human DNA helix occupy too much space in the cell. Small proteins are responsible for packing the DNA into units called nucleosomes. b. Stained chromosomes: Chromosomes are stained with A-T (G bands) and G-C (R bands) base pair specific dyes. When they are stained, the mitotic chromosomes have a banded structure that unambiguously identifies each chromosome of a karyotype. Each band contains millions of DNA nucleotide pairs which do not correspond to any functional structure. Adapted from K.F. Jorgenson, J.H. van de Sande, and C.C. Lin, Chromosoma 68:287-302, 1978. c. Karyotype of a male: The human haploid genome contains 3,000,000,000 DNA nucleotide pairs, divided among twenty two (22) pairs of autosomes and one pair of sex chromosomes.

  20. The human sex ratio from conception to birth

    PubMed Central

    Orzack, Steven Hecht; Stubblefield, J. William; Akmaev, Viatcheslav R.; Colls, Pere; Munné, Santiago; Scholl, Thomas; Steinsaltz, David; Zuckerman, James E.

    2015-01-01

    We describe the trajectory of the human sex ratio from conception to birth by analyzing data from (i) 3- to 6-d-old embryos, (ii) induced abortions, (iii) chorionic villus sampling, (iv) amniocentesis, and (v) fetal deaths and live births. Our dataset is the most comprehensive and largest ever assembled to estimate the sex ratio at conception and the sex ratio trajectory and is the first, to our knowledge, to include all of these types of data. Our estimate of the sex ratio at conception is 0.5 (proportion male), which contradicts the common claim that the sex ratio at conception is male-biased. The sex ratio among abnormal embryos is male-biased, and the sex ratio among normal embryos is female-biased. These biases are associated with the abnormal/normal state of the sex chromosomes and of chromosomes 15 and 17. The sex ratio may decrease in the first week or so after conception (due to excess male mortality); it then increases for at least 10–15 wk (due to excess female mortality), levels off after ?20 wk, and declines slowly from 28 to 35 wk (due to excess male mortality). Total female mortality during pregnancy exceeds total male mortality. The unbiased sex ratio at conception, the increase in the sex ratio during the first trimester, and total mortality during pregnancy being greater for females are fundamental insights into early human development. PMID:25825766

  1. The human sex ratio from conception to birth.

    PubMed

    Orzack, Steven Hecht; Stubblefield, J William; Akmaev, Viatcheslav R; Colls, Pere; Munné, Santiago; Scholl, Thomas; Steinsaltz, David; Zuckerman, James E

    2015-04-21

    We describe the trajectory of the human sex ratio from conception to birth by analyzing data from (i) 3- to 6-d-old embryos, (ii) induced abortions, (iii) chorionic villus sampling, (iv) amniocentesis, and (v) fetal deaths and live births. Our dataset is the most comprehensive and largest ever assembled to estimate the sex ratio at conception and the sex ratio trajectory and is the first, to our knowledge, to include all of these types of data. Our estimate of the sex ratio at conception is 0.5 (proportion male), which contradicts the common claim that the sex ratio at conception is male-biased. The sex ratio among abnormal embryos is male-biased, and the sex ratio among normal embryos is female-biased. These biases are associated with the abnormal/normal state of the sex chromosomes and of chromosomes 15 and 17. The sex ratio may decrease in the first week or so after conception (due to excess male mortality); it then increases for at least 10-15 wk (due to excess female mortality), levels off after ?20 wk, and declines slowly from 28 to 35 wk (due to excess male mortality). Total female mortality during pregnancy exceeds total male mortality. The unbiased sex ratio at conception, the increase in the sex ratio during the first trimester, and total mortality during pregnancy being greater for females are fundamental insights into early human development. PMID:25825766

  2. Analysis of sex-chromosome aneuploidy in interspecific backcross progeny between the laboratory mouse strain C57BL\\/6 and Mus spretus

    Microsoft Academic Search

    Y. Matsuda; V. M. Chapman

    1992-01-01

    Sex-chromosomal aneuploidy was identified in four female progeny of 200 interspecific backcrosses between laboratory mice (C57BL\\/6Ros) and Mus spretus. The progeny included two 39, XO monosomy mice resulting from a backcross with M. spretus, as well as a 41, XXX trisomic mouse and a 40, XX\\/41, XXX mosaic mouse resulting from two separate backcrosses with C57BL\\/6 mice. The parental origin

  3. Chromosomal abnormality at 6p25.1-25.3 identifies a susceptibility locus for hypothalamic hamartoma associated with epilepsy.

    PubMed

    Kerrigan, John F; Kruer, Michael C; Corneveaux, Jason; Panganiban, Corrie B; Itty, Abraham; Reiman, David; Ng, Yu-Tze; Stephan, Dietrich A; Craig, David W

    2007-06-01

    The pathogenesis of hypothalamic hamartoma (HH) associated with epilepsy is unknown. We have identified an individual with HH and refractory epilepsy exhibiting subtle dysmorphic features. High-resolution karyotype identified a duplication of the terminal end of 6p (6p25.1-25.3), confirmed by fluorescent in situ-hybridization (FISH). Copy number analysis with high-density (250K) single nucleotide polymorphism (SNP) genotyping microarrays characterized the abnormality as a series of amplified regions between 1.4 Mb and 10.2 Mb, with a small tandem deletion from 8.8 Mb to 9.7 Mb. There are 38 RefSeq genes within the duplicated regions, and no known coding sequences within the deletion. This unique patient helps identify 6p25.1-25.3 as a possible susceptibility locus for sporadic HH. PMID:17512701

  4. Human X chromosome

    SciTech Connect

    NONE

    1993-12-31

    Chapter 21, describes in detail the human X chromosome. X chromatin (or Barr body) formation, inactivation and reactivation of the X chromosome, X;Y translocations, and sex reversal are discussed. 30 refs., 3 figs.

  5. Sex-specific differences in chromosome-dependent regulation of vascular reactivity in female consomic rat strains from a SS × BN cross

    PubMed Central

    Kunert, Mary Pat; Dwinell, Melinda R.; Drenjancevic Peric, Ines; Lombard, Julian H.

    2008-01-01

    High-throughput studies in the Medical College of Wisconsin Program for Genomic Applications (Physgen) were designed to link chromosomes with physiological function in consomic strains derived from a cross between Dahl salt-sensitive SS/JrHsdMcwi (SS) and Brown Norway normotensive BN/NHsdMcwi (BN) rats. The specific goal of the vascular protocol was to characterize the responses of aortic rings from these strains to vasoconstrictor and vasodilator stimuli (phenylephrine, acetylcholine, sodium nitroprusside, and bath hypoxia) to identify chromosomes that either increase or decrease vascular reactivity to these vasoactive stimuli. Because previous studies demonstrated sex-specific quantitative trait loci (QTLs) related to regulation of cardiovascular phenotypes in an F2 cross between the parental strains, males and females of each consomic strain were included in all experiments. As there were significant sex-specific differences in aortic sensitivity to vasoconstrictor and vasodilator stimuli compared with the parental SS strain, we report the results of the females separately from the males. There were also sex-specific differences in aortic ring sensitivity to these vasoactive stimuli in consomic strains that were fed a high-salt diet (4% NaCl) for 3 wk to evaluate salt-induced changes in vascular reactivity. Differences in genetic architecture could contribute to sex-specific differences in the development and expression of cardiovascular diseases via differential regulation and expression of genes. Our findings are the first to link physiological traits with specific chromosomes in female SS rats and support the idea that sex is an important environmental variable that plays a role in the expression and regulation of genes. PMID:18509103

  6. Systematic chromosome examination of two families with schizophrenia and two families with manic depressive illness

    SciTech Connect

    Friedrich, U.; Mors, O.; Ewald, H. [Aarhus Univ. (Denmark)] [Aarhus Univ. (Denmark)

    1996-02-16

    Systematic and detailed chromosome analysis, combined with a semistructured interview, was performed in 2 families with schizophrenia and in 2 families with manic depressive illness. Prometaphase technique did not reveal any subtle structural chromosome abnormalities. However, in standard techniques, gain and loss of sex chromosomes were observed. This occurred in patients at a younger age than in unaffected persons. This gives rise to the suspicion that sex chromosome aneuploidy may somehow be related to the development of psychosis. But since the data set is small, especially with respect to schizophrenia, further studies are needed to elucidate this observation. In one family, cosegregation of the disease locus with a marker on chromosome 21 was seen. Therefore, further research should determine if chromosome 21 contains a gene for manic depressive illness. 10 refs., 3 figs., 2 tabs.

  7. Genomics of sex determination.

    PubMed

    Zhang, Jisen; Boualem, Adnane; Bendahmane, Abdelhafid; Ming, Ray

    2014-04-01

    Sex determination is a major switch in the evolutionary history of angiosperm, resulting 11% monoecious and dioecious species. The genomic sequences of papaya sex chromosomes unveiled the molecular basis of recombination suppression in the sex determination region, and candidate genes for sex determination. Identification and analyses of sex determination genes in cucurbits and maize demonstrated conservation of sex determination mechanism in one lineage and divergence between the two systems. Epigenetic control and hormonal influence of sex determination were elucidated in both plants and animals. Intensive investigation of potential sex determination genes in model species will improve our understanding of sex determination gene network. Such network will in turn accelerate the identification of sex determination genes in dioecious species with sex chromosomes, which are burdensome due to no recombination in sex determining regions. The sex determination genes in dioecious species are crucial for understanding the origin of dioecy and sex chromosomes, particularly in their early stage of evolution. PMID:24682067

  8. Human Spermatogenic Failure Purges Deleterious Mutation Load from the Autosomes and Both Sex Chromosomes, including the Gene DMRT1

    PubMed Central

    Thompson, Emma; Carvalho, Filipa; Gonçalves, Joăo; Huang, Ni; Matthiesen, Rune; Noordam, Michiel J.; Quintela, Inés; Ramu, Avinash; Seabra, Catarina; Wilfert, Amy B.; Dai, Juncheng; Downie, Jonathan M.; Fernandes, Susana; Guo, Xuejiang; Sha, Jiahao; Amorim, António; Barros, Alberto; Carracedo, Angel; Hu, Zhibin; Hurles, Matthew E.; Moskovtsev, Sergey; Ober, Carole; Paduch, Darius A.; Schiffman, Joshua D.; Schlegel, Peter N.; Sousa, Mário; Carrell, Douglas T.; Conrad, Donald F.

    2013-01-01

    Gonadal failure, along with early pregnancy loss and perinatal death, may be an important filter that limits the propagation of harmful mutations in the human population. We hypothesized that men with spermatogenic impairment, a disease with unknown genetic architecture and a common cause of male infertility, are enriched for rare deleterious mutations compared to men with normal spermatogenesis. After assaying genomewide SNPs and CNVs in 323 Caucasian men with idiopathic spermatogenic impairment and more than 1,100 controls, we estimate that each rare autosomal deletion detected in our study multiplicatively changes a man's risk of disease by 10% (OR 1.10 [1.04–1.16], p<2×10?3), rare X-linked CNVs by 29%, (OR 1.29 [1.11–1.50], p<1×10?3), and rare Y-linked duplications by 88% (OR 1.88 [1.13–3.13], p<0.03). By contrasting the properties of our case-specific CNVs with those of CNV callsets from cases of autism, schizophrenia, bipolar disorder, and intellectual disability, we propose that the CNV burden in spermatogenic impairment is distinct from the burden of large, dominant mutations described for neurodevelopmental disorders. We identified two patients with deletions of DMRT1, a gene on chromosome 9p24.3 orthologous to the putative sex determination locus of the avian ZW chromosome system. In an independent sample of Han Chinese men, we identified 3 more DMRT1 deletions in 979 cases of idiopathic azoospermia and none in 1,734 controls, and found none in an additional 4,519 controls from public databases. The combined results indicate that DMRT1 loss-of-function mutations are a risk factor and potential genetic cause of human spermatogenic failure (frequency of 0.38% in 1306 cases and 0% in 7,754 controls, p?=?6.2×10?5). Our study identifies other recurrent CNVs as potential causes of idiopathic azoospermia and generates hypotheses for directing future studies on the genetic basis of male infertility and IVF outcomes. PMID:23555275

  9. Attention-Deficit Hyperactivity Disorder Symptoms in Children and Adolescents with Sex Chromosome Aneuploidy: XXY, XXX, XYY, and XXYY

    PubMed Central

    Tartaglia, Nicole R.; Ayari, Natalie; Hutaff-Lee, Christa; Boada, Richard

    2012-01-01

    Objective Attentional problems, hyperactivity, and impulsivity have been described as behavioral features associated with sex chromosome aneuploidy (SCA). In this study, the authors compare attention-deficit hyperactivity disorder (ADHD) symptoms in 167 participants aged 6 to 20 years with 4 types of SCA (XXY n = 56, XYY n = 33, XXX n = 25, and XXYY n = 53). They also evaluate factors associated with ADHD symptomatology (cognitive and adaptive scores, prenatal vs postnatal ascertainment) and describe the clinical response to psychopharmacologic medications in a subset of patients treated for ADHD. Methods Evaluation included medical and developmental history, cognitive and adaptive functioning assessment, and parent and teacher ADHD questionnaires containing DSM-IV criteria. Results In the total study group, 58% (96/167) met DSM-IV criteria for ADHD on parent-report questionnaires (36% in XXY, 52% in XXX, 76% in XYY, and 72% in XXYY). The Inattentive subtype was most common in XXY and XXX, whereas the XYY and XXYY groups were more likely to also have hyperactive/impulsive symptoms. There were no significant differences in Verbal, Performance, or Full Scale IQ between children with symptom scores in the ADHD range compared with those below the ADHD range. However, adaptive functioning scores were significantly lower in the group whose scores in the ADHD range were compared with those of the group who did not meet ADHD DSMIV criteria. Those with a prenatal diagnosis of XXY were less likely to meet criteria for ADHD compared with the postnatally diagnosed group. Psychopharmacologic treatment with stimulants was effective in 78.6% (66/84). Conclusions Children and adolescents with SCA are at increased risk for ADHD symptoms. Recommendations for ADHD evaluation and treatment in consideration of other aspects of the SCA medical and behavioral phenotype are provided. PMID:22333574

  10. Chromosome studies in the red howler monkey, Alouatta seniculus stramineus (Platyrrhini, Primates): description of an X1X2Y1Y2\\/X1X1X2X2sex-chromosome system and karyological comparisons with other subspecies

    Microsoft Academic Search

    M. M. C. Lima; H. N. Seuánez

    1991-01-01

    In the red howler monkey, Alouatta seniculus stramineus (2n = 47, 48, or 49), variations in diploid chromosome number are due to different numbers of microchromo-somes. Males exhibit a Y autosome translocation involving the short arm of an individual biarmed autosome. Consequently, the sex-chromosome constitution in the male is X1X2Y1Y2with X1 representing the original X chromosome, X2 the biarmed autosome

  11. Karyotype and identification of sex in two endangered crane species

    USGS Publications Warehouse

    Goodpasture, C.; Seluja, G.; Gee, G.

    1992-01-01

    A laboratory procedure for sex identification of monomorphic birds was developed using modern cytological methods of detecting chromosome abnormalities in human amniotic fluid samples. A pin feather is taken from a pre-fledging bird for tissue culture and karyotype analysis. Through this method, the sex was identified and the karyotype described of the whooping crane (Grus americana) and the Mississippi sandhill crane (G. canadensis pulla). Giemsa-stained karyotypes of these species showed an identical chromosome constitution with 2n = 78 + 2. However, differences in the amount of centromeric heterochromatin were observed in the Mississippi sandhill crane when compared to the whooping crane C-banded karyotype.

  12. The Y Chromosome

    ERIC Educational Resources Information Center

    Offner, Susan

    2010-01-01

    The Y chromosome is of great interest to students and can be used to teach about many important biological concepts in addition to sex determination. This paper discusses mutation, recombination, mammalian sex determination, sex determination in general, and the evolution of sex determination in mammals. It includes a student activity that…

  13. Cytogenetics of bisexual/unisexual species of Poecilia. I. C-bands, Ag-NOR polymorphisms, and sex chromosomes in three populations of Poecilia latipinna.

    PubMed

    Sola, L; Monaco, P J; Rasch, E M

    1990-01-01

    Three populations of the North American cyprinodont fish Poecilia latipinna, considered to be one of the progenitor species of the gynogenetic unisexual P. formosa, were analyzed by C-banding and Ag-staining. C-bands were found to be polymorphic, and Ag-staining showed a high degree of variability in both the number and location of nucleolus organizer regions. The C-banding and Ag-staining patterns allow, to a certain extent, to distinguish individual specimens from each of these populations. Females of the three populations were found to have a heteromorphic chromosome pair, which was frequently identifiable with Giemsa staining and always after C-banding. This pair could be interpreted as sex chromosomes of the ZW/ZZ type. PMID:2369844

  14. The G516T CYP2B6 Germline Polymorphism Affects the Risk of Acute Myeloid Leukemia and Is Associated with Specific Chromosomal Abnormalities

    PubMed Central

    Daraki, Aggeliki; Zachaki, Sophia; Koromila, Theodora; Diamantopoulou, Paraskevi; Pantelias, Gabriel E.; Sambani, Constantina; Aleporou, Vasiliki; Kollia, Panagoula; Manola, Kalliopi N.

    2014-01-01

    The etiology of acute myeloid leukemia (AML) underlies the influence of genetic variants in candidate genes. The CYP2B6 enzyme detoxifies many genotoxic xenobiotics, protecting cells from oxidative damage. The CYP2B6 gene is subjected to a single-nucleotide polymorphism (G516T) with heterozygotes (GT) and homozygotes (TT) presenting decreased enzymatic activity. This case-control study aimed to investigate the association of CYP2B6 G516T polymorphism with the susceptibility of AML and its cytogenetic and clinical characteristics. Genotyping was performed on 619 AML patients and 430 healthy individuals using RCR-RFLP and a novel LightSNip assay. The major finding was a statistically higher frequency of the variant genotypes (GT and TT) in patients compared to the controls (GT:38.8% vs 29.8% and TT:9.3% vs 5.3% respectively) (p<0.001). More specifically, a significantly higher frequency of GT+TT genotypes in de novo AML patients (46.6%) and an immensely high frequency of TT in secondary AML (s-AML) (20.5%) were observed. The statistical analysis showed that the variant T allele was approximately 1.5-fold and 2.4-fold higher in de novo and s-AML respectively than controls. Concerning FAB subtypes, the T allele presented an almost 2-fold increased in AML-M2. Interestingly, a higher incidence of the TT genotype was observed in patients with abnormal karyotypes. In particular, positive correlations of the mutant allele were found in patients carrying specific chromosomal aberrations [-7/del(7q), -5/del(5q), +8, +21 or t(8;21)], complex or monosomal karyotypes. Finally, a strikingly higher frequency of TT genotype was also observed in patients stratified to the poor risk group. In conclusion, our results provide evidence for the involvement of the CYP2B6 polymorphism in AML susceptibility and suggest a possible role of the CYP2B6 genetic background on the development of specific chromosomal aberrations. PMID:24586425

  15. Commentary: Unravelling the Effects of Additional Sex Chromosomes on Cognition and Communication--Reflections on Lee et al. (2012)

    ERIC Educational Resources Information Center

    Bishop, Dorothy V. M.

    2012-01-01

    Most people have 23 pairs of chromosomes; one set from the mother and one from the father. However, nondisjunction errors during meiosis can lead to a case of trisomy, where there are three rather than two chromosomes. Although such events are not uncommon, they are usually lethal, and account for a high proportion of spontaneous abortions. There…

  16. B-chromosome evolution.

    PubMed Central

    Camacho, J P; Sharbel, T F; Beukeboom, L W

    2000-01-01

    B chromosomes are extra chromosomes to the standard complement that occur in many organisms. They can originate in a number of ways including derivation from autosomes and sex chromosomes in intra- and interspecies crosses. Their subsequent molecular evolution resembles that of univalent sex chromosomes, which involves gene silencing, heterochromatinization and the accumulation of repetitive DNA and transposons. B-chromosome frequencies in populations result from a balance between their transmission rates and their effects on host fitness. Their long-term evolution is considered to be the outcome of selection on the host genome to eliminate B chromosomes or suppress their effects and on the B chromosome's ability to escape through the generation of new variants. Because B chromosomes interact with the standard chromosomes, they can play an important role in genome evolution and may be useful for studying molecular evolutionary processes. PMID:10724453

  17. Multiplex ligation-dependent probe amplification workflow for the detection of submicroscopic chromosomal abnormalities in patients with developmental delay/intellectual disability

    PubMed Central

    2013-01-01

    Background Array based comparative genomic hybridization (arrayCGH) has been increasingly used as the method of choice for diagnosis of patients with unexplained developmental delay/intellectual disability (DD/ID) but is not universally available for the high throughput use in routine practice. The next-generation sequencing (NGS) techniques, emerging as a new tool in clinical diagnostics, are at present quite labour-intensive and expensive. Since multiplex ligation-dependent probe amplification (MLPA) is relatively fast, easily interpreted and cost-effective, it is still a method of choice for screening large cohorts of patients with DD/ID. Results We prospectively studied a cohort of 150 patients with DD/ID with or without dysmorphic features or additional congenital abnormalities. We used two distinct MLPA kits, SALSA P036 and P070, for subtelomere screening and MLPA kit SALSA P245 for the 21 common microdeletion syndromes. Subtelomere analysis was performed by both kits in all patients. All imbalances were verified by follow-up MLPA kits. The MLPA analysis revealed chromosome aberrations in 21 (14%) cases: 11 subtelomeric rearrangements and 10 microdeletions. Conclusions We have presented the results of the investigation of patients with DD/ID obtained by using a combination of the MLPA sets for subtelomere aberrations and microdeletion syndromes followed by the confirmation of the aberrant results by the region-specific MLPA kits. The use of two subtelomeric kits per patient and investigation of all aberrations by follow-up sets has reduced the rate of false positive and negative results and improved the diagnostic yield. The relatively low cost, simplicity and reliability makes MLPA an effective first-tier cytogenetic diagnostic test for screening large cohorts of DD/ID patients. PMID:23383958

  18. Gene content, organization and molecular evolution of plant organellar genomes and sex chromosomes: insights from the case of the liverwort Marchantia polymorpha.

    PubMed

    Ohyama, Kanji; Takemura, Miho; Oda, Kenji; Fukuzawa, Hideya; Kohchi, Takayuki; Nakayama, Sigeki; Ishizaki, Kimitsune; Fujisawa, Masaki; Yamato, Katsuyuki

    2009-01-01

    The complete nucleotide sequence of chloroplast DNA (121,025 base pairs, bp) from a liverwort, Marchantia polymorpha, has made clear the entire gene organization of the chloroplast genome. Quite a few genes encoding components of photosynthesis and protein synthesis machinery have been identified by comparative computer analysis. We also determined the complete nucleotide sequence of the liverwort mitochondrial DNA and deduced 96 possible genes in the sequence of 186,608 bp. The complete chloroplast genome encodes twenty introns (19 group II and 1 group I) in 18 different genes. One of the chloroplast group II introns separates a ribosomal protein gene in a trans-position. The mitochondrial genome contains thirty-two introns (25 group II and 7 group I) in the coding regions of 17 genes. From the evolutionary point of view, we describe the origin of organellar introns and give evidence for vertical and horizontal intron transfers and their intragenomic propagation. Furthermore, we describe the gene organization of the Y chromosome in the dioecious liverwort M. polymorpha, the first detailed view of a Y chromosome in a haploid organism. On the 10 megabase (Mb) Y chromosome, 64 genes are identified, 14 of which are detected only in the male genome. These 14 genes are expressed in reproductive organs but not in vegetative thalli, suggesting their participation in male reproductive functions. These findings indicate that the Y and X chromosomes share the same ancestral autosome and support the prediction that in a haploid organism essential genes on sex chromosomes are more likely to persist than in a diploid organism. PMID:19282647

  19. CHROMOSOMAL ABNORMALITIES AMONG WELDER TRAINEES

    EPA Science Inventory

    Serial cytogenetic observations were made on a group of 273 military recruits who were being trained as welders at Aberdeen, Maryland. The trainees were being exposed to presumably increased levels of ozone in the course of their welding school experience, and it was the purpose ...

  20. Fate of SRY, PABY, DYS1, DYZ3 and DYZ1 loci in Indian patients harbouring sex chromosomal anomalies

    Microsoft Academic Search

    Anu Bashamboo; Mohammed Mahidur Rahman; Aparna Prasad; Sebastian Padinjarel Chandy; Jamal Ahmad; Sher Ali

    2005-01-01

    We analysed chromosomes, conducted hormonal assays and screened genomic DNA of 34 patients with or without detectable Y chromosome for the presence\\/absence of SRY, PABY, DYS1, DYZ3 and DYZ1 loci and for mutations in the SRY gene. The samples studied represented cases of oligozoospermia, cryptorchidism, Swyer syndrome, Turner syndrome, male pseudoher- maphroditism, XXY female syndrome, Klinefelter's syndrome, repeated abortion and

  1. Mapping of sex-linked genes onto the genome sequence using various aberrations of the Z chromosome in Bombyx mori.

    PubMed

    Fujii, Tsuguru; Abe, Hiroaki; Katsuma, Susumu; Mita, Kazuei; Shimada, Toru

    2008-12-01

    Many strains of Bombyx mori carry chromosomal aberrations, and they are useful resources for integration between phenotypes and genomic sequences. We compared the molecular structures of three kinds of Z chromosomes, i.e., two strains with chromosome deletions and one strain with translocation involving the Z chromosome. Using polymerase chain reaction markers, we showed that: (1) the Z(1) chromosome lacks more than 6Mb, including the proximal end; (2) the Z(Vg) chromosome lacks 1.5Mb in the interstitial portion; and (3) the +(od)p(Sa)+(p)W carries a 0.6-Mb Z-derived fragment surrounding the +(od) gene. The breakpoint junctions of these deletions and a translocation were precisely determined. Through deletion mapping, we narrowed down the regions where distinct oily (od), vestigial (Vg), and muscle dystrophy (Md) are located and identified a candidate gene for od. A retroposon-mediated deletion in BmBLOS2--the Bombyx gene homologous to human "biogenesis of lysosome-related organelles complex-1, subunit 2''--was detected in the od mutant. Although the genes responsible for Vg and Md were not definitively identified, we propose the candidate genes on the basis of their locations and phenotypes. PMID:19216995

  2. Localization of male-specifically expressed MROS genes of Silene latifolia by PCR on flow-sorted sex chromosomes and autosomes.

    PubMed Central

    Kejnovský, E; Vrána, J; Matsunaga, S; Soucek, P; Siroký, J; Dolezel, J; Vyskot, B

    2001-01-01

    The dioecious white campion Silene latifolia (syn. Melandrium album) has heteromorphic sex chromosomes, XX in females and XY in males, that are larger than the autosomes and enable their separation by flow sorting. The group of MROS genes, the first male-specifically expressed genes in dioecious plants, was recently identified in S. latifolia. To localize the MROS genes, we used the flow-sorted X chromosomes and autosomes as a template for PCR with internal primers. Our results indicate that the MROS3 gene is located in at least two copies tandemly arranged on the X chromosome with additional copy(ies) on the autosome(s), while MROS1, MROS2, and MROS4 are exclusively autosomal. The specificity of PCR products was checked by digestion with a restriction enzyme or reamplification using nested primers. Homology search of databases has shown the presence of five MROS3 homologues in A. thaliana, four of them arranged in two tandems, each consisting of two copies. We conclude that MROS3 is a low-copy gene family, connected with the proper pollen development, which is present not only in dioecious but also in other dicot plant species. PMID:11454773

  3. Chronic exposure of mutant DISC1 mice to lead produces sex-dependent abnormalities consistent with schizophrenia and related mental disorders: a gene-environment interaction study.

    PubMed

    Abazyan, Bagrat; Dziedzic, Jenifer; Hua, Kegang; Abazyan, Sofya; Yang, Chunxia; Mori, Susumu; Pletnikov, Mikhail V; Guilarte, Tomas R

    2014-05-01

    The glutamatergic hypothesis of schizophrenia suggests that hypoactivity of the N-methyl-D-aspartate receptor (NMDAR) is an important factor in the pathophysiology of schizophrenia and related mental disorders. The environmental neurotoxicant, lead (Pb(2+)), is a potent and selective antagonist of the NMDAR. Recent human studies have suggested an association between prenatal Pb(2+) exposure and the increased likelihood of schizophrenia later in life, possibly via interacting with genetic risk factors. In order to test this hypothesis, we examined the neurobehavioral consequences of interaction between Pb(2+) exposure and mutant disrupted in schizophrenia 1 (mDISC1), a risk factor for major psychiatric disorders. Mutant DISC1 and control mice born by the same dams were raised and maintained on a regular diet or a diet containing moderate levels of Pb(2+). Chronic, lifelong exposure of mDISC1 mice to Pb(2+) was not associated with gross developmental abnormalities but produced sex-dependent hyperactivity, exaggerated responses to the NMDAR antagonist, MK-801, mildly impaired prepulse inhibition of the acoustic startle, and enlarged lateral ventricles. Together, these findings support the hypothesis that environmental toxins could contribute to the pathogenesis of mental disease in susceptible individuals. PMID:23716713

  4. Sleep and Sex: What Can Go Wrong? A Review of the Literature on Sleep Related Disorders and Abnormal Sexual Behaviors and Experiences

    PubMed Central

    Schenck, Carlos H.; Arnulf, Isabelle; Mahowald, Mark W.

    2007-01-01

    Study Objectives: To formulate the first classification of sleep related disorders and abnormal sexual behaviors and experiences. Design: A computerized literature search was conducted, and other sources, such as textbooks, were searched. Results: Many categories of sleep related disorders were represented in the classification: parasomnias (confusional arousals/sleepwalking, with or without obstructive sleep apnea; REM sleep behavior disorder); sleep related seizures; Kleine-Levin syndrome (KLS); severe chronic insomnia; restless legs syndrome; narcolepsy; sleep exacerbation of persistent sexual arousal syndrome; sleep related painful erections; sleep related dissociative disorders; nocturnal psychotic disorders; miscellaneous states. Kleine-Levin syndrome (78 cases) and parasomnias (31 cases) were most frequently reported. Parasomnias and sleep related seizures had overlapping and divergent clinical features. Thirty-one cases of parasomnias (25 males; mean age, 32 years) and 7 cases of sleep related seizures (4 males; mean age, 38 years) were identified. A full range of sleep related sexual behaviors with self and/or bed partners or others were reported, including masturbation, sexual vocalizations, fondling, sexual intercourse with climax, sexual assault/rape, ictal sexual hyperarousal, ictal orgasm, and ictal automatism. Adverse physical and/or psychosocial effects from the sleepsex were present in all parasomnia and sleep related seizure cases, but pleasurable effects were reported by 5 bed partners and by 3 patients with sleep related seizures. Forensic consequences were common, occurring in 35.5% (11/31) of parasomnia cases, with most (9/11) involving minors. All parasomnias cases reported amnesia for the sleepsex, in contrast to 28.6% (2/7) of sleep related seizure cases. Polysomnography (without penile tumescence monitoring), performed in 26 of 31 parasomnia cases, documented sexual moaning from slow wave sleep in 3 cases and sexual intercourse during stage 1 sleep/wakefulness in one case (with sex provoked by the bed partner). Confusional arousals (CAs) were diagnosed as the cause of “sleepsex” (“sexsomnia”) in 26 cases (with obstructive sleep apnea [OSA] comorbidity in 4 cases), and sleepwalking in 2 cases, totaling 90.3% (28/31) of cases being NREM sleep parasomnias. REM behavior disorder was the presumed cause in the other 3 cases. Bedtime clonazepam therapy was effective in 90% (9/10) of treated parasomnia cases; nasal continuous positive airway pressure therapy was effective in controlling comorbid OSA and CAs in both treated cases. All five treated patients with sleep related sexual seizures responded to anticonvulsant therapy. The hypersexuality in KLS, which was twice as common in males compared to females, had no reported effective therapy. Conclusions: A broad range of sleep related disorders associated with abnormal sexual behaviors and experiences exists, with major clinical and forensic consequences. Citation: Schenck CH; Arnulf I; Mahowald MW et al. Sleep and sex: what can go wrong? A review of the literature on sleep related disorders and abnormal sexual behaviors and experiences. SLEEP 2007;30(6):683-702. PMID:17580590

  5. Narrowing Down the Mapping of Plant Sex-Determination Regions Using New Y-Chromosome-Specific Markers and Heavy-Ion Beam Irradiation-Induced Y-Deletion Mutants in Silene latifolia.

    PubMed

    Fujita, Naoko; Torii, Chihiro; Ishii, Kotaro; Aonuma, Wataru; Shimizu, Yuji; Kazama, Yusuke; Abe, Tomoko; Kawano, Shigeyuki

    2012-02-01

    Silene latifolia is a well-studied model system for plant XY sex determination. Three maleness factors are thought to function on the Y chromosome, gynoecium suppression factor (GSF), stamen-promoting factor (SPF), and male fertility factor (MFF), and their deletions result in hermaphrodites, anther defects, and pollen defects, respectively. Although a framework map of the Y chromosome exists, the sex determination genes have not been identified, and no markers close enough to potentially be used for BAC library screening are yet available. The analysis of Y deletion mutants by Y-chromosome-specific STS markers is an efficient way to isolate sex determination regions, but more Y-specific STS markers are needed to accelerate the exploration of sex determination factors. Herein, we report a marker design method that uses simple sequence repeats, which is especially effective on the Y chromosome of S. latifolia because it contains many simple sequence repeats. Six new Y-chromosome-specific STS markers were obtained, SmicSy1-6. These were used to detect relatively small Y deletion sites in heavy-ion beam irradiation-induced mutants. The mapping of male sex determination regions was narrowed down by using more markers and smaller-sized Y deletion mutants. One new marker, SmicSy6, is a proximal marker to SPF and, thus, a second index for SPF. The region including SPF is thought to be located between two SPF proximal markers. The flower phenotype correlates with the deletion size of SPF using SPF proximal markers. These findings represent new progress in isolating the sex determination factor, which has been studied for more than 50 years. PMID:22384405

  6. The obscure events contributing to the evolution of an incipient sex chromosome in Populus A retrospective working hypothesis.

    SciTech Connect

    Tuskan, Gerald A [ORNL; Tschaplinski, Timothy J [ORNL; Chen, Jay [ORNL; Labbe, Jessy L [ORNL; Ranjan, Priya [ORNL; DiFazio, Steven P [West Virginia University; Slavov, Goncho T. [West Virginia University; Yin, Tongming [ORNL

    2012-01-01

    Genetic determination of gender is a fundamental developmental and evolutionary process in plants. Although it appears that dioecy in Populus is partially genetically controlled, the precise gender-determining systems remain unclear. The recently-released second draft assembly and annotated gene set of the Populus genome provided an opportunity to re-visit this topic. We hypothesized that over evolutionary time, selective pressure has reformed the genome structure and gene composition in the peritelomeric region of the chromosome XIX which has resulted in a distinctive genome structure and cluster of genes contributing to gender determination in Populus. Multiple lines of evidence support this working hypothesis. First, the peritelomeric region of the chromosome XIX contains significantly fewer single nucleotide polymorphisms than the rest of Populus genome and has a distinct evolutionary history. Second, the peritelomeric end of chromosome XIX contains the largest cluster of the nucleotide-binding site-leucine-rich repeat (NBS-LRR) class of disease resistances genes in the entire Populus genome. Third, there is a high occurrence of small microRNAs on chromosome XIX coincident to the region containing the putative gender-determining locus and the major cluster of NBS-LRR genes. Further, by analyzing the metabolomic profiles of floral bud in male and female Populus trees using a gas chromatography-mass spectrometry, we found there are gender-specific accumulations of phenolic glycosides. Taken together, these findings provide new insights into the genetic control of gender determination in Populus.

  7. In situ hybridization of chromosome 6 on fine-needle aspirates from breast carcinomas: Comparison of numerical abnormalities and ER\\/PgR status and staining pattern

    Microsoft Academic Search

    Torill Sauer; Kahsai Beraki; Peter Wilhelm Jebsen; Eli Ormerod; Oddvar Naess

    1997-01-01

    The estrogen receptor (ER) gene is located on chromosome 6. The aim of our study was to investigate whether numerical chromo- somal aberrations were reflected in estrogen\\/progesterone receptor (PgR) status and staining pattern. Fine-needle aspirates from 51 breast carcinomas were investigated immunocytochemically for ER\\/PgR and by in situ hybridization technique using digoxigenin- labeled a-satellite probe for chromosome 6. Cases with$70%

  8. Brain morphological abnormalities in 49,XXXXY syndrome: A pediatric magnetic resonance imaging study???

    PubMed Central

    Blumenthal, Jonathan D.; Baker, Eva H.; Lee, Nancy Raitano; Wade, Benjamin; Clasen, Liv S.; Lenroot, Rhoshel K.; Giedd, Jay N.

    2013-01-01

    As a group, people with the sex chromosome aneuploidy 49,XXXXY have characteristic physical and cognitive/behavioral tendencies, although there is high individual variation. In this study we use magnetic resonance imaging (MRI) to examine brain morphometry in 14 youth with 49,XXXXY compared to 42 age-matched healthy controls. Total brain size was significantly smaller (t = 9.0, p < .001), and rates of brain abnormalities such as colpocephaly, plagiocephaly, periventricular cysts, and minor craniofacial abnormalities were significantly increased. White matter lesions were identified in 50% of subjects, supporting the inclusion of 49,XXXXY in the differential diagnosis of small multifocal white matter lesions. Further evidence of abnormal development of white matter was provided by the smaller cross sectional area of the corpus callosum. These results suggest that increased dosage of genes on the X chromosome has adverse effects on white matter development. PMID:23667827

  9. The battle of the sexes after fertilization: behaviour of paternal and maternal chromosomes in the early mammalian embryo

    Microsoft Academic Search

    Thomas Haaf

    2001-01-01

    In the early diploid mammalian embryo, a father's chromosomes don't mix with the mother's until some time after fertilization.\\u000a This topological genome separation is preserved up to the four-cell embryo stage and then gradually disappears. Unlike maternal\\u000a DNA, sperm DNA arrives in an almost crystalline structure, heavily modified with methylcytosines (MeCs), which keep genes\\u000a inactive. Compartmentalization of the nucleus according

  10. The control of sex chromatin

    Microsoft Academic Search

    O. J. Miller; Dorothy Warburton

    1968-01-01

    Sex chromatin counts for more than 50 individuals with three or more X chromosomes in their complement were analyzed. The observed distribution of cells with 0, 1, 2,...n sex chromatin bodies in polysomic-X individuals was compared with the binomial distribution expected on the assumption of a constant probability that an X chromosome will form a visible sex chromatin body. The

  11. Identification and molecular characterization of a sex chromosome rearrangement causing a soft and pliable (spli) larval body phenotype in the silkworm, Bombyx mori.

    PubMed

    Fujii, Tsuguru; Kuwazaki, Seigo; Yamamoto, Kimiko; Abe, Hiroaki; Ohnuma, Akio; Katsuma, Susumu; Mita, Kazuei; Shimada, Toru

    2010-01-01

    We carried out genetic and cytogenetic analyses of X-ray-induced deleterious Z chromosomes that result in a soft and pliable (spli) phenotype in the silkworm, Bombyx mori. In a B. mori strain with a spli phenotype, we found the Z chromosome broken between the sch (1-21.5) and od (1-49.6) loci. We also found a chromosomal fragment bearing a fifth-chromosome locus for egg and eye pigmentation fused to a Z chromosome fragment. By means of fluorescence in situ hybridization using bacterial artificial chromosome clones as probes, we confirmed that the fused chromosome is composed of a fragment of chromosome 5 and a fragment of the Z chromosome. Moreover, a predicted gene, GA002017, the Bombyx ortholog of the Drosophila gene acj6 (Bmacj6), was completely deleted by the Z chromosome breakage event. The relationship between Bmacj6 and the spli phenotype is discussed. PMID:20130748

  12. Reduced adaptation of a non-recombining neo-Y chromosome 

    E-print Network

    Bachtrog, Doris; Charlesworth, Brian

    2002-03-21

    Sex chromosomes are generally believed to have descended from a pair of homologous autosomes. Suppression of recombination between the ancestral sex chromosomes led to the genetic degeneration of the Y chromosome1. In ...

  13. Incomplete sister chromatid separation of long chromosome arms

    Microsoft Academic Search

    W. Rens; L. Torosantucci; F. Degrassi; M. A. Ferguson-Smith

    2006-01-01

    Chromosome segregation ensures the equal partitioning of chromosomes at mitosis. However, long chromosome arms may pose a problem for complete sister chromatid separation. In this paper we report on the analysis of cell division in primary cells from field vole Microtus agrestis, a species with 52 chromosomes including two giant sex chromosomes. Dual chromosome painting with probes specific for the

  14. A Prenatally Ascertained De Novo Terminal Deletion of Chromosomal Bands 1q43q44 Associated with Multiple Congenital Abnormalities in a Female Fetus

    PubMed Central

    Christopoulou, Georgia; Donoghue, Jacqueline; Konstantinidou, Anastasia E.; Velissariou, Voula

    2015-01-01

    Terminal deletions in the long arm of chromosome 1 result in a postnatally recognizable disorder described as 1q43q44 deletion syndrome. The size of the deletions and the resulting phenotype varies among patients. However, some features are common among patients as the chromosomal regions included in the deletions. In the present case, ultrasonography at 22 weeks of gestation revealed choroid plexus cysts (CPCs) and a single umbilical artery (SUA) and therefore amniocentesis was performed. Chromosomal analysis revealed a possible terminal deletion in 1q and high resolution array CGH confirmed the terminal 1q43q44 deletion and estimated the size to be approximately 8?Mb. Following termination of pregnancy, performance of fetopsy allowed further clinical characterization. We report here a prenatal case with the smallest pure terminal 1q43q44 deletion, that has been molecularly and phenotypically characterized. In addition, to our knowledge this is the first prenatal case reported with 1q13q44 terminal deletion and Pierre-Robin sequence (PRS). Our findings combined with review data from the literature show the complexity of the genetic basis of the associated syndrome. PMID:25722899

  15. Phosphatase and tensin homolog, deleted on chromosome 10 deficiency in brain causes defects in synaptic structure, transmission and plasticity, and myelination abnormalities.

    PubMed

    Fraser, M M; Bayazitov, I T; Zakharenko, S S; Baker, S J

    2008-01-24

    The phosphatidylinositol 3-kinase (PI3K) signaling pathway modulates growth, proliferation and cell survival in diverse tissue types and plays specialized roles in the nervous system including influences on neuronal polarity, dendritic branching and synaptic plasticity. The tumor-suppressor phosphatase with tensin homology (PTEN) is the central negative regulator of the PI3K pathway. Germline PTEN mutations result in cancer predisposition, macrocephaly and benign hamartomas in many tissues, including Lhermitte-Duclos disease, a cerebellar growth disorder. Neurological abnormalities including autism, seizures and ataxia have been observed in association with inherited PTEN mutation with variable penetrance. It remains unclear how loss of PTEN activity contributes to neurological dysfunction. To explore the effects of Pten deficiency on neuronal structure and function, we analyzed several ultra-structural features of Pten-deficient neurons in Pten conditional knockout mice. Using Golgi stain to visualize full neuronal morphology, we observed that increased size of nuclei and somata in Pten-deficient neurons was accompanied by enlarged caliber of neuronal projections and increased dendritic spine density. Electron microscopic evaluation revealed enlarged abnormal synaptic structures in the cerebral cortex and cerebellum. Severe myelination defects included thickening and unraveling of the myelin sheath surrounding hypertrophic axons in the corpus callosum. Defects in myelination of axons of normal caliber were observed in the cerebellum, suggesting intrinsic abnormalities in Pten-deficient oligodendrocytes. We did not observe these abnormalities in wild-type or conditional Pten heterozygous mice. Moreover, conditional deletion of Pten drastically weakened synaptic transmission and synaptic plasticity at excitatory synapses between CA3 and CA1 pyramidal neurons in the hippocampus. These data suggest that Pten is involved in mechanisms that control development of neuronal and synaptic structures and subsequently synaptic function. PMID:18082964

  16. Detection of amplified or deleted chromosomal regions

    DOEpatents

    Stokke, T.; Pinkel, D.; Gray, J.W.

    1995-12-05

    The present invention relates to in situ hybridization methods for the identification of new chromosomal abnormalities associated with various diseases. In particular, it provides probes which are specific to a region of amplification in chromosome 20. 3 figs.

  17. Dynamic gene order on the Silene latifolia Y chromosome

    Microsoft Academic Search

    Elaine C. Howell; Susan J. Armstrong; Dmitry A. Filatov

    2011-01-01

    Dioecious Silene latifolia evolved heteromorphic sex chromosomes within the last ten million years, making it a species of choice for studies of the\\u000a early stages of sex chromosome evolution in plants. About a dozen genes have been isolated from its sex chromosomes and basic\\u000a genetic and deletion maps exist for the X and Y chromosomes. However, discrepancies between Y chromosome

  18. Diverse outcomes of homologous recombination in the human Y chromosome

    E-print Network

    Lange, Julian H. (Julian Hendrik)

    2008-01-01

    Mammalian sex chromosomes began diverging from an ordinary pair of autosomes roughly 300 million years ago. Inversions in the evolving Y chromosome sequentially suppressed recombination with the X chromosome. While ...

  19. High incidence of chromosomal abnormalities at 1p36 and 9p21 in early-stage central type squamous cell carcinoma and squamous dysplasia of bronchus detected by autofluorescence bronchoscopy.

    PubMed

    Shibukawa, Kiyoko; Miyokawa, Naoyuki; Tokusashi, Yoshihiko; Sasaki, Takaaki; Osanai, Shinobu; Ohsaki, Yoshinobu

    2009-07-01

    Heavy smokers with central type squamous cell carcinoma (SCC) frequently have multiple cancerous lesions in the bronchus. Autofluorescence bronchoscopy (AFB) is useful in the detection of early bronchogenic cancer and dysplastic lesions. We investigated the loss of heterozygosity (LOH) and microsatellite instability (MSI) and expression of four proteins in 13 early stage SCC (early SCC) and 9 squamous dysplasia detected by AFB and 19 cases of surgically resected invasive SCC (invasive SCC). In early SCC and squamous dysplasia, LOH/MSI of chromosome 1p36 was found in 62 and 33%, respectively, and of 9p21 in 54 and 63%, respectively. TAp73 expression of early SCC and squamous dysplasia was lower than that of normal bronchial epithelium, and p16 expression was not detectable in these lesions. These results suggested that the genetic abnormalities had already developed in the early stage of carcinogenesis of SCC, including squamous dysplasia. The AFB system was able to reveal abnormal autofluorescence in these precancerous lesions, including squamous dysplasia. PMID:19513508

  20. Ring Chromosome 13 and Ambiguous Genitalia

    PubMed Central

    Özsu, Elif; Ye?iltepe Mutlu, Gül; ?pekçi, Belk?s

    2014-01-01

    Ambiguous genitalia, known to be associated with sex chromosome disorders, may also be seen with autosomal chromosome anomalies. Herein, we report a case with ambiguous genitalia and ring chromosome 13. Ring chromosome 13 is a rare genetic anomaly in which the loss of genetic material determines the clinical spectrum. PMID:24932608

  1. Ring chromosome 13 and ambiguous genitalia.

    PubMed

    Ozsu, Elif; Ye?iltepe Mutlu, Gül; Ipekçi, Belk?s

    2014-01-01

    Ambiguous genitalia, known to be associated with sex chromosome disorders, may also be seen with autosomal chromosome anomalies. Herein, we report a case with ambiguous genitalia and ring chromosome 13. Ring chromosome 13 is a rare genetic anomaly in which the loss of genetic material determines the clinical spectrum. PMID:24932608

  2. The DNA sequence of the human X chromosome

    Microsoft Academic Search

    Mark T. Ross; Darren V. Grafham; Alison J. Coffey; Steven Scherer; Kirsten McLay; Donna Muzny; Matthias Platzer; Gareth R. Howell; Christine Burrows; Christine P. Bird; Adam Frankish; Frances L. Lovell; Kevin L. Howe; Jennifer L. Ashurst; Robert S. Fulton; Ralf Sudbrak; Gaiping Wen; Matthew C. Jones; Matthew E. Hurles; T. Daniel Andrews; Carol E. Scott; Stephen Searle; Juliane Ramser; Adam Whittaker; Rebecca Deadman; Nigel P. Carter; Sarah E. Hunt; Rui Chen; Andrew Cree; Preethi Gunaratne; Paul Havlak; Anne Hodgson; Michael L. Metzker; Stephen Richards; Graham Scott; David Steffen; Erica Sodergren; David A. Wheeler; Kim C. Worley; Rachael Ainscough; Kerrie D. Ambrose; M. Ali Ansari-Lari; Swaroop Aradhya; Robert I. S. Ashwell; Anne K. Babbage; Claire L. Bagguley; Andrea Ballabio; Ruby Banerjee; Gary E. Barker; Karen F. Barlow; Ian P. Barrett; Karen N. Bates; David M. Beare; Helen Beasley; Oliver Beasley; Alfred Beck; Graeme Bethel; Karin Blechschmidt; Nicola Brady; Sarah Bray-Allen; Anne M. Bridgeman; Andrew J. Brown; Mary J. Brown; David Bonnin; Elspeth A. Bruford; Christian Buhay; Paula Burch; Deborah Burford; Joanne Burgess; Wayne Burrill; John Burton; Jackie M. Bye; Carol Carder; Laura Carrel; Joseph Chako; Joanne C. Chapman; Dean Chavez; Ellson Chen; Guan Chen; Yuan Chen; Zhijian Chen; Craig Chinault; Alfredo Ciccodicola; Sue Y. Clark; Graham Clarke; Chris M. Clee; Sheila Clegg; Kerstin Clerc-Blankenburg; Karen Clifford; Vicky Cobley; Charlotte G. Cole; Jen S. Conquer; Nicole Corby; Richard E. Connor; Robert David; Joy Davies; Clay Davis; John Davis; Oliver Delgado; Denise DeShazo; Pawandeep Dhami; Yan Ding; Huyen Dinh; Steve Dodsworth; Heather Draper; Shannon Dugan-Rocha; Andrew Dunham; Matthew Dunn; K. James Durbin; Ireena Dutta; Tamsin Eades; Matthew Ellwood; Alexandra Emery-Cohen; Helen Errington; Kathryn L. Evans; Louisa Faulkner; Fiona Francis; John Frankland; Audrey E. Fraser; Petra Galgoczy; James Gilbert; Rachel Gill; Gernot Glöckner; Simon G. Gregory; Susan Gribble; Coline Griffiths; Russell Grocock; Yanghong Gu; Rhian Gwilliam; Cerissa Hamilton; Elizabeth A. Hart; Alicia Hawes; Paul D. Heath; Katja Heitmann; Steffen Hennig; Judith Hernandez; Bernd Hinzmann; Sarah Ho; Michael Hoffs; Phillip J. Howden; Elizabeth J. Huckle; Jennifer Hume; Paul J. Hunt; Adrienne R. Hunt; Judith Isherwood; Leni Jacob; David Johnson; Sally Jones; Pieter J. de Jong; Shirin S. Joseph; Stephen Keenan; Susan Kelly; Joanne K. Kershaw; Ziad Khan; Petra Kioschis; Sven Klages; Andrew J. Knights; Anna Kosiura; Christie Kovar-Smith; Gavin K. Laird; Cordelia Langford; Stephanie Lawlor; Margaret Leversha; Lora Lewis; Wen Liu; Christine Lloyd; David M. Lloyd; Hermela Loulseged; Jane E. Loveland; Jamieson D. Lovell; Ryan Lozado; Jing Lu; Rachael Lyne; Jie Ma; Manjula Maheshwari; Lucy H. Matthews; Jennifer McDowall; Stuart McLaren; Amanda McMurray; Patrick Meidl; Thomas Meitinger; Sarah Milne; George Miner; Shailesh L. Mistry; Margaret Morgan; Sidney Morris; Ines Müller; James C. Mullikin; Ngoc Nguyen; Gabriele Nordsiek; Gerald Nyakatura; Christopher N. O'Dell; Geoffery Okwuonu; Sophie Palmer; Richard Pandian; David Parker; Julia Parrish; Shiran Pasternak; Dina Patel; Alex V. Pearce; Danita M. Pearson; Sarah E. Pelan; Lesette Perez; Keith M. Porter; Yvonne Ramsey; Kathrin Reichwald; Susan Rhodes; Kerry A. Ridler; David Schlessinger; Mary G. Schueler; Harminder K. Sehra; Charles Shaw-Smith; Hua Shen; Elizabeth M. Sheridan; Ratna Shownkeen; Carl D. Skuce; Michelle L. Smith; Elizabeth C. Sotheran; Helen E. Steingruber; Charles A. Steward; Roy Storey; R. Mark Swann; David Swarbreck; Paul E. Tabor; Stefan Taudien; Tineace Taylor; Brian Teague; Karen Thomas; Andrea Thorpe; Kirsten Timms; Alan Tracey; Steve Trevanion; Anthony C. Tromans; Michele d'Urso; Daniel Verduzco; Donna Villasana; Lenee Waldron; Melanie Wall; Qiaoyan Wang; James Warren; Georgina L. Warry; Xuehong Wei; Anthony West; Siobhan L. Whitehead; Mathew N. Whiteley; Jane E. Wilkinson; David L. Willey; Gabrielle Williams; Leanne Williams; Angela Williamson; Helen Williamson; Laurens Wilming; Rebecca L. Woodmansey; Paul W. Wray; Jennifer Yen; Jingkun Zhang; Jianling Zhou; Huda Zoghbi; Sara Zorilla; David Buck; Richard Reinhardt; Annemarie Poustka; André Rosenthal; Hans Lehrach; Alfons Meindl; Patrick J. Minx; LaDeana W. Hillier; Huntington F. Willard; Richard K. Wilson; Robert H. Waterston; Catherine M. Rice; Mark Vaudin; Alan Coulson; David L. Nelson; George Weinstock; John E. Sulston; Richard Durbin; Tim Hubbard; Richard A. Gibbs; Stephan Beck; Jane Rogers; David R. Bentley

    2005-01-01

    The human X chromosome has a unique biology that was shaped by its evolution as the sex chromosome shared by males and females. We have determined 99.3% of the euchromatic sequence of the X chromosome. Our analysis illustrates the autosomal origin of the mammalian sex chromosomes, the stepwise process that led to the progressive loss of recombination between X and

  3. Gallery 31: mys inserted in chromosomes

    NSDL National Science Digital Library

    2009-12-26

    Repetitive DNA can have preferred insertion sites. In this example, yellow represents the distribution of mys (a type of LINE) over a mouse genome where chromosomes are orange. There are more mys inserted in the sex (X) chromosomes.

  4. Xp22.3 interstitial deletion: a recognizable chromosomal abnormality encompassing VCX3A and STS genes in a patient with X-linked ichthyosis and mental retardation.

    PubMed

    Ben Khelifa, Hela; Soyah, Najla; Ben-Abdallah-Bouhjar, Inesse; Gritly, Ryma; Sanlaville, Damien; Elghezal, Hatem; Saad, Ali; Mougou-Zerelli, Soumaya

    2013-09-25

    X-linked ichthyosis is a genetic disorder affecting the skin and caused by a deficit in the steroid sulfatase enzyme (STS), often associated with a recurrent microdeletion at Xp22.31. Most of the STS deleted patients have X-linked ichthyosis as the only clinical feature and it is believed that patients with more complex disorders including mental retardation could be present as a result of contiguous gene deletion. In fact, VCX3A gene, a member of the VCX (variable charge, X chromosome) gene family, was previously proposed as the candidate gene for X-linked non-specific mental retardation in patients with X-linked ichthyosis. We report on a boy with familial ichthyosis, dysmorphic features and moderate mental retardation with approximately 2 Mb interstitial deletion on Xp22.3 involving VCX3A and STS genes. PMID:23791652

  5. A retrospective chromosome studies among Iranian infertile women: Report of 21 years

    PubMed Central

    Azimi, Cyrus; Khaleghian, Malihea; Farzanfar, Farideh

    2013-01-01

    Background: The infertility is an important health problem, affecting about 15% of couples. The important role of genetic factors in pathogenesis of infertility is now increasingly recognized. The value of karyotyping women in the routine work-out of couples referred for sterility has long been recommended. Objective: The aim of this study was to define the frequency of all chromosomal aberrations among women which referred to our department due to infertility during the 21-year period. Materials and Methods: In this 21-year retrospective study, for the first time, we investigated 896 women which referred to our department due to infertility during 1986 to 2006. For chromosome analysis, heparinized peripheral blood samples were cultured, harvested and banded according to standard methods. Results: Out of 896 patients, 710 patients (79.24%) had a normal karyotype, and 186 patients (20.76%) showed abnormal karyotype. Among the abnormal ones 48 patients (25.81%) showed Turner's syndrome (45,X), and 45 patients (24.19%) were sex reversal with 46,XY karyotype. The rest of 93 patients (50%) revealed a wide range of chromosome abnormalities. Conclusion: Our results emphasized the importance of the standard cytogenetic methods in assessing the genetic characteristics of infertile females, which allows detecting a variety of somatic chromosome abnormalities, because some of these may interfere with the success of reproduction. PMID:24639762

  6. The Performance of Whole Genome Amplification Methods and Next-Generation Sequencing for Pre-Implantation Genetic Diagnosis of Chromosomal Abnormalities.

    PubMed

    Li, Na; Wang, Li; Wang, Hui; Ma, Minyue; Wang, Xiaohong; Li, Yi; Zhang, Wenke; Zhang, Jianguang; Cram, David S; Yao, Yuanqing

    2015-04-20

    Reliable and accurate pre-implantation genetic diagnosis (PGD) of patient's embryos by next-generation sequencing (NGS) is dependent on efficient whole genome amplification (WGA) of a representative biopsy sample. However, the performance of the current state of the art WGA methods has not been evaluated for sequencing. Using low template DNA (15 pg) and single cells, we showed that the two PCR-based WGA systems SurePlex and MALBAC are superior to the REPLI-g WGA multiple displacement amplification (MDA) system in terms of consistent and reproducible genome coverage and sequence bias across the 24 chromosomes, allowing better normalization of test to reference sequencing data. When copy number variation sequencing (CNV-Seq) was applied to single cell WGA products derived by either SurePlex or MALBAC amplification, we showed that known disease CNVs in the range of 3-15 Mb could be reliably and accurately detected at the correct genomic positions. These findings indicate that our CNV-Seq pipeline incorporating either SurePlex or MALBAC as the key initial WGA step is a powerful methodology for clinical PGD to identify euploid embryos in a patient's cohort for uterine transplantation. PMID:25953353

  7. Sequence of the mouse Y chromosome

    E-print Network

    Alföldi, Jessica E

    2008-01-01

    The mouse Y chromosome has been studied for over 50 years, from the early sex determination and immunological phenotypes attributed to it in the 1950s, to the several mouse Y permatogenic phenotypes and the sex ratio ...

  8. CHROMOSOMAL LOCATION AND GENE PAUCITY IN THE MALE SPECIFIC REGION ON PAPAYA Y CHROMOSOME

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sex chromosomes in flowering plants evolved recently and many of them remain homomorphic, including those in papaya. We investigated the chromosomal location of papaya’s small male specific region of the hermaphrodite Y (Yh) chromosome (MSY) and its genomic features. We conducted chromosome fluoresc...

  9. Purine and pyrimidine metabolism in human gliomas: relation to chromosomal aberrations.

    PubMed

    Bardot, V; Dutrillaux, A M; Delattre, J Y; Vega, F; Poisson, M; Dutrillaux, B; Luccioni, C

    1994-08-01

    Chromosomal aberrations in human gliomas are principally numerical. In tumours of low malignancy, karyotypes are frequently normal, but occasionally an excess of chromosome 7 and a loss of sex chromosome are observed. In highly malignant tumours, the most frequent aberrations are gain of chromosome 7, loss of chromosome 10 and less frequently losses or deletions of chromosomes 9, 22, 6, 13 and 14 or gains of chromosomes 19 and 20. To understand the meaning of these chromosome imbalances, the relationships between chromosome abnormalities and metabolic disturbances were studied. The losses or deletions observed affected principally chromosomes carrying genes encoding enzymes involved in purine metabolism. The activities of ten enzymes were measured: adenosine kinase, adenine phosphoribosyltransferase, adenylate kinase, methylthioadenosine phosphorylase, hypoxanthine phosphoribosyltransferase, adenylosuccinate lyase, inosine monophosphate dehydrogenase, adenosine deaminase, nucleoside phosphorylase and adenosine monophosphate deaminase. In parallel, two enzymes involved in pyrimidine metabolism, thymidine kinase and thymidylate synthase (TS), were studied. The activities of all these enzymes were measured on samples from 30 human primary glial tumours with low or high malignancy, six xenografted tumours at different passages, four portions of normal brain tissue and four non-glial brain neoplasms. As suggested by cytogenetic data, the enzymatic results showed a relatively low activity of purine metabolism in glial tumours when compared with normal brain and non-glial brain neoplasms. Considering the two enzymes involved in pyrimidine metabolism, only TS had higher activity in glial tumours of high malignancy than in normal brain. In comparison with normal brain, the balance between salvage and de novo pathways changes in gliomas, and even more in grafted tumours, in favour of de novo synthesis. The relation between chromosomes and metabolic imbalances does not correspond to a simple gene dosage effect in these tumours. These data suggest that the decrease of adenosine metabolism occurs before chromosomal aberrations appear, since it is observed in tumours of low malignancy when most karyotypes are still normal, and that the de novo pathway increases with tumour progression. PMID:8054268

  10. Human chromosomes: Structure, behavior, and effects

    SciTech Connect

    Therman, E.; Susman, M.

    1993-12-31

    The book `Human Chromosomes: Structure, Behavior, and Effects` covers the most important topics regarding human chromosomes and current research in cytogenetics. Attention is given both to structure and function of autosomes and sex chromosomes, as well as definitions and causes of chromosomal aberrations. This often involves discussion about various aspects of the cell cycle (both mitosis and meiosis). Methods and techniques involved in researching and mapping human chromosomes are also discussed.

  11. Nail abnormalities

    MedlinePLUS

    Beau's lines; Fingernail abnormalities; Spoon nails; Onycholysis; Leukonychia; Koilonychia; Brittle nails ... of the nail bed from the nail plate (onycholysis). Severe illness or surgery may cause horizontal depressions ...

  12. Chromosomal breakpoints characterization of two supernumerary ring chromosomes 20.

    PubMed

    Guediche, N; Brisset, S; Benichou, J-J; Guérin, N; Mabboux, P; Maurin, M-L; Bas, C; Laroudie, M; Picone, O; Goldszmidt, D; Prévot, S; Labrune, P; Tachdjian, G

    2010-02-01

    The occurrence of an additional ring chromosome 20 is a rare chromosome abnormality, and no common phenotype has been yet described. We report on two new patients presenting with a supernumerary ring chromosome 20 both prenatally diagnosed. The first presented with intrauterine growth retardation and some craniofacial dysmorphism, and the second case had a normal phenotype except for obesity. Conventional cytogenetic studies showed for each patient a small supernumerary marker chromosome (SMC). Using fluorescence in situ hybridization, these SMCs corresponded to ring chromosomes 20 including a part of short and long arms of chromosome 20. Detailed molecular cytogenetic characterization showed different breakpoints (20p11.23 and 20q11.23 for Patient 1 and 20p11.21 and 20q11.21 for Patient 2) and sizes of the two ring chromosomes 20 (13.6 Mb for case 1 and 4.8 Mb for case 2). Review of the 13 case reports of an extra r(20) ascertained postnatally (8 cases) and prenatally (5 cases) showed varying degrees of phenotypic abnormalities. We document a detailed molecular cytogenetic chromosomal breakpoints characterization of two cases of supernumerary ring chromosomes 20. These results emphasize the need to characterize precisely chromosomal breakpoints of supernumerary ring chromosomes 20 in order to establish genotype-phenotype correlation. This report may be helpful for prediction of natural history and outcome, particularly in prenatal diagnosis. PMID:20101685

  13. Chromosomal Aberrations and Schizophrenia

    PubMed Central

    Bassett, Anne S.

    2011-01-01

    Chromosomal aberrations associated with schizophrenic disorders may suggest regions in which to focus a search for genes predisposing to schizophrenia by a linkage strategy. As for other genetic illnesses, chromosomal abnormalities may also provide useful tools for subsequent physical mapping, fine localisation, and isolation of important susceptibility genes. Identification of several chromosomal aberrations may be especially important, given the unknown pathophysiology, the paucity of known brain genes, and the probable genetic heterogeneity of schizophrenia and manic-depression. However, because psychiatric disorders are common and inherited in a complex manner, researchers must use caution when drawing inferences about associations with chromosomal aberrations. Reported abnormalities involving autosomes (chromosomes 1 –22) associated with psychotic disorders are reviewed. Their relevance to linkage studies localising genes for schizophrenia was estimated by standardised criteria for specificity, diagnosis, family history, and overall weight of evidence. Four ‘possibly relevant’ chromosomal regions were identified: 5q, 11q, 18q, and 19p. This paper outlines strategies for future studies to detect new chromosomal aberrations associated with major psychotic disorders that may be relevant to isolating the genes for schizophrenia. PMID:1393302

  14. Dynamic gene order on the Silene latifolia Y chromosome.

    PubMed

    Howell, Elaine C; Armstrong, Susan J; Filatov, Dmitry A

    2011-06-01

    Dioecious Silene latifolia evolved heteromorphic sex chromosomes within the last ten million years, making it a species of choice for studies of the early stages of sex chromosome evolution in plants. About a dozen genes have been isolated from its sex chromosomes and basic genetic and deletion maps exist for the X and Y chromosomes. However, discrepancies between Y chromosome maps led to the proposal that individual Y chromosomes may differ in gene order. Here, we use an alternative approach, with fluorescence in situ hybridization (FISH), to locate individual genes on S. latifolia sex chromosomes. We demonstrate that gene order on the Y chromosome differs between plants from two populations. We suggest that dynamic gene order may be a general property of Y chromosomes in species with XY systems, in view of recent work demonstrating that the gene order on the Y chromosomes of humans and chimpanzees are dramatically different. PMID:21327830

  15. The Genetic Analysis of Snf: A Drosophila Sex Determination Gene Required for Activation of Sex-Lethal in Both the Germline and the Soma

    PubMed Central

    Salz, H. K.

    1992-01-01

    Our analysis demonstrates that snf is a positive regulator of Sex-lethal in both the germline and the soma. In the germline, unregulated expression of Sex-lethal can bypass the requirement for snf(+) gene function, implying that snf is required for Sex-lethal activity in the germline. This conclusion is supported by the finding that the Sex-lethal transcription pattern is abnormal in a snf mutant background. In the soma, activation of Sex-lethal appears to be sensitive to snf gene dosage only when the probability of Sex-lethal activation has been otherwise reduced. We also show that the activity of one of the constitutive Sex-lethal alleles (Sxl(M1)) is sensitive to snf gene dosage, demonstrating that, in spite of its constitutive behavior in some assays, Sxl(M1) is still subject to some regulation. In spite of snf's role in the somatic activation of Sex-lethal, no lethal alleles of snf were isolated in a screen of ~25,000 chromosomes. The observation that the existing snf mutations present a lethal phenotype only in certain genetic backgrounds suggests that snf is required, but is not essential, for the activation of Sex-lethal in the soma. In contrast, snf does appear to be essential for activation of Sex-lethal in the germline, as evidenced by its female-sterile phenotype. PMID:1551576

  16. Chromosome 9 of Ellobius lutescens is the X chromosome

    Microsoft Academic Search

    Walther Vogel; Peter Steinbach; Mahmoud Djalali; Karl Mehnert; Sher Ali; Jörg Thomas Epplen

    1988-01-01

    Ellobius lutescens carries an apparently identical karyotype (2n = 17) in both sexes. On the basis of indirect evidence the unpaired chromosome 9 has been considered to represent the X chromosome of this species. We have obtained data to substantiate this view by four different techniques. After fusion of HPRT- RAG cells with E. lutescens fibroblasts we demonstrated that the

  17. Substitution Rates in a New Silene latifolia Sex-Linked Gene, SlssX\\/Y

    Microsoft Academic Search

    Dmitry A. Filatov

    2004-01-01

    Dioecious white campion Silene latifolia has sex chromosomal sex determination, with homogametic (XX) females and heterogametic (XY) males. This species has become popular in studies of sex chromosome evolution. However, the lack of genes isolated from the X and Y chromosomes of this species is a major obstacle for such studies. Here, I report the isolation of a new sex-linked

  18. An XX/XY sex microchromosome system in a freshwater turtle, Chelodina longicollis (Testudines: Chelidae) with genetic sex determination

    E-print Network

    Canberra, University of

    An XX/XY sex microchromosome system in a freshwater turtle, Chelodina longicollis (Testudines: Chelidae) with genetic sex determination Tariq Ezaz1*, Nicole Valenzuela2 , Frank Gru¨tzner1 , Ikuo Miura3, microchromosomes, sex chromosomes Abstract Heteromorphic sex chromosomes are rare in turtles, having been described

  19. [Rheumatic diseases and sex differences].

    PubMed

    Ochiai, Moeko; Yamanaka, Hisashi

    2015-04-01

    Recently a concept of "sex differences" in medicine has been spreading. It is well known that autoimmune diseases, especially rheumatoid arthritis or systemic lupus erythematosus mostly affect women, and it is clear that there is a strong sex differences in many rheumatic diseases. Sex difference influences to progression or prognosis of the disease. Although the mechanisms of sex difference are not clear, the influence of sex hormones or sex chromosomes which gives immune system is partially elucidated. In addition, sex hormones may become the future new treatment target, and progress in the study regarding this event is expected in the future. PMID:25936155

  20. PCR in situ followed by microdissection allows whole chromosome painting probes to be made from single microdissected chromosomes

    Microsoft Academic Search

    Allen T. Christian; Holly E. Garcia; James D. Tucker

    1999-01-01

    .   Whole-chromosome painting probes (WCPs) and chromosome-arm painting probes (CAPs) are an integral part of the cytogenetic\\u000a analysis of chromosome abnormalities. While these are routinely made by chromosome microdissection, multiple copies of the\\u000a dissected region have been necessary to achieve a library sufficiently complex to provide adequate painting. Performing multiple\\u000a dissections of chromosomes or chromosome regions is time consuming and