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1

Chromosome abnormalities in sperm of individuals with constitutional sex chromosomal abnormalities  

Microsoft Academic Search

The most common type of karyotype abnormality detected in infertile subjects is represented by Klinefelter’s syndrome, and the most frequent non-chromosomal alteration is represented by Y chromosome long arm microdeletions. Here we report our experience and a review of the literature on sperm sex chromosome aneuploidies in these two conditions. Non mosaic 47,XXY Klinefelter patients (12 subjects) show a significantly

A. Ferlin; A. Garolla; C. Foresta

2005-01-01

2

Sex Chromosome  

NSDL National Science Digital Library

A sex chromosome is one of the two chromosomes that specify an organism's genetic sex. Humans have two kinds of sex chromosomes, one called X and the other Y. Normal females possess two X chromosomes and normal males one X and one Y.

BEGIN:VCARD VERSION:2.1 FN:Darryl Leja N:Leja;Darryl ORG:National Human Genome Research Institute REV:2005-04-14 END:VCARD

2005-04-14

3

[Disorders of sex chromosome].  

PubMed

Disorders of sex chromosome, X and Y, consist of abnormality of the number or structure of the sex chromosome. Because sex chromosomes have a variety of genes related to sexual differentiation, disorders of sex chromosome induce a variety of disorders of sexual differentiation. At first, in this title, the process of normal sexual differentiation is shown. Classical disorders of sex chromosome are Klinefelter syndrome, XX male, XYY male, Turner syndrome, XXX female, and XY female. True hermphroiditism, mixed gonadal dysgenesis, and pure gonadal dysgenesis are also included, because most of these disorders have abnormal sex chromosome. Molecular analysis of sex chromosome is clarifying disorders with a minute abnormality of sex chromosome. They include male infertility, premature ovarian failure, and fragile X syndrome. Explanations of the above disorders are given briefly. PMID:9396296

Namiki, M; Koh, E

1997-11-01

4

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

Microsoft Academic Search

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

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

2008-01-01

5

Analysis of sex chromosome abnormalities using X and Y chromosome DNA tiling path arrays  

PubMed Central

Background: Array comparative genomic hybridisation is a powerful tool for the detection of copy number changes in the genome. Methods: A human X and Y chromosome tiling path array was developed for the analysis of sex chromosome aberrations. Results: Normal X and Y chromosome profiles were established by analysis with DNA from normal fertile males and females. Detection of infertile males with known Y deletions confirmed the competence of the array to detect AZFa, AZFb and AZFc deletions and to distinguish between different AZFc lesions. Examples of terminal and interstitial deletions of Xp (previously characterised through cytogenetic and microsatellite analysis) have been assessed using the arrays, thus both confirming and refining the established deletion breakpoints. Breakpoints in iso?Yq, iso?Yp and X–Y translocation chromosomes and X–Y interchanges in XX males are also amenable to analysis. Discussion: The resolution of the tiling path clone set used allows breakpoints to be placed within 100–200?kb, permitting more precise genotype/phenotype correlations. These data indicate that the combined X and Y tiling path arrays provide an effective tool for the investigation and diagnosis of sex chromosome copy number aberrations and rearrangements.

Karcanias, A C; Ichimura, K; Mitchell, M J; Sargent, C A; Affara, N A

2007-01-01

6

Chromosomal Abnormalities and Schizophrenia  

PubMed Central

Schizophrenia is a common and serious psychiatric illness with strong evidence for genetic causation, but no specific loci yet identified. Chromosomal abnormalities associated with schizophrenia may help to understand the genetic complexity of the illness. This paper reviews the evidence for associations between chromosomal abnormalities and schizophrenia and related disorders. The results indicate that 22q11.2 microdeletions detected by fluorescence in-situ hybridization (FISH) are significantly associated with schizophrenia. Sex chromosome abnormalities seem to be increased in schizophrenia but insufficient data are available to indicate whether schizophrenia or related disorders are increased in patients with sex chromosome aneuploidies. Other reports of chromosomal abnormalities associated with schizophrenia have the potential to be important adjuncts to linkage studies in gene localization. Advances in molecular cytogenetic techniques (i.e., FISH) have produced significant increases in rates of identified abnormalities in schizophrenia, particularly in patients with very early age at onset, learning difficulties or mental retardation, or dysmorphic features. The results emphasize the importance of considering behavioral phenotypes, including adult onset psychiatric illnesses, in genetic syndromes and the need for clinicians to actively consider identifying chromosomal abnormalities and genetic syndromes in selected psychiatric patients.

BASSETT, ANNE S.; CHOW, EVA W.C.; WEKSBERG, ROSANNA

2011-01-01

7

Chromosome Abnormalities  

MedlinePLUS

... chromosome has attached to another at the centromere. Inversions: A portion of the chromosome has broken off, ... individual and was not inherited from the parents. Inversions - a portion of the chromosome has broken off, ...

8

Epilepsy and chromosomal abnormalities  

Microsoft Academic Search

Background  Many chromosomal abnormalities are associated with Central Nervous System (CNS) malformations and other neurological alterations,\\u000a among which seizures and epilepsy. Some of these show a peculiar epileptic and EEG pattern. We describe some epileptic syndromes\\u000a frequently reported in chromosomal disorders.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Detailed clinical assessment, electrophysiological studies, survey of the literature.\\u000a \\u000a \\u000a \\u000a Results  In some of these congenital syndromes the clinical presentation and EEG

Giovanni Sorge; Anna Sorge

2010-01-01

9

Sex Chromosomes and Speciation  

Microsoft Academic Search

Studies of reproductive isolation between animal species have shown (i) that if one sex of the hybrids between two species is sterile or inviable, it is usually the heterogametic sex (Haldane's rule), and (ii) the genes on the sex chromosomes play a particularly large role in hybrid sterility and inviability. We propose an explanation for these two observations which is

Eva Jablonka; Marion J. Lamb

1991-01-01

10

Chromosomal abnormalities and mental illness  

Microsoft Academic Search

Linkage studies of mental illness have provided suggestive evidence of susceptibility loci over many broad chromosomal regions. Pinpointing causative gene mutations by conventional linkage strategies alone is problematic. The breakpoints of chromosomal abnormalities occurring in patients with mental illness may be more direct pointers to the relevant gene locus. Publications that describe patients where chromosomal abnormalities co-exist with mental illness

D J MacIntyre; D H R Blackwood; D J Porteous; B S Pickard; W J Muir

2003-01-01

11

Meiotic chromosome abnormalities in human spermatogenesis.  

PubMed

The last few years have witnessed an explosion in the information about chromosome abnormalities in human sperm and the meiotic events that predispose to these abnormalities. We have determined that all chromosomes are susceptible to nondisjunction, but chromosomes 21 and 22 and, especially, the sex chromosomes have an increased frequency of aneuploidy. Studies are just beginning on the effects of potential mutagens on the chromosomal constitution of human sperm. The effects of pesticides and cancer therapeutic agents have been reviewed. In the last decade, there has been a great impetus to study chromosome abnormalities in sperm from infertile men because the advent of intracytoplasmic sperm injection (ICSI) made it possible for these men to father pregnancies. A large number of studies have demonstrated that infertile men have an increased frequency of chromosomally abnormal sperm and children, even when they have a normal somatic karyotype. Meiotic studies on the pachytene stage of spermatogenesis have demonstrated that infertile men have impaired chromosome synapsis, a significantly decreased frequency of recombination, and an increased frequency of chromosomes completely lacking a recombination site. Such errors make these cells susceptible to meiotic arrest and the production of aneuploid gametes. PMID:16714098

Martin, Renée H

2006-08-01

12

Chromosomal abnormalities and embryo development in recurrent miscarriage couples  

Microsoft Academic Search

BACKGROUND: Chromosomal abnormalities are an important cause of spontaneous abortion and recurrent mis- carriage (RM). Therefore, we have analysed the incidence of chromosomal abnormalities and embryo development in patients with RM. METHODS: Preimplantation genetic diagnosis (PGD) was performed on 71 couples with RM and 28 couples undergoing PGD for sex-linked diseases (control group). Chromosomes 13, 16, 18, 21, 22, X

C. Rubio; C. Simon; F. Vidal; L. Rodrigo; T. Pehlivan; J. Remohi; A. Pellicer

2003-01-01

13

Interpreting chromosomal abnormalities using Prolog.  

PubMed

This paper describes an expert system for interpreting the standard notation used to represent human chromosomal abnormalities, namely, the International System for Human Cytogenetic Nomenclature. Written in Prolog, this program is very powerful, easy to maintain, and portable. The system can be used as a front end to any database that employs cytogenetic notation, such as a patient registry. PMID:2185921

Cooper, G; Friedman, J M

1990-04-01

14

Distribution of alpha 1-antitrypsin (PI) phenotypes in chromosome abnormalities.  

PubMed

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 of meiosis. Phenotypic distributions of each group were statistically similar to control populations of cord bloods and bloods donors. PMID:6971795

Mulley, J C; Sutherland, G R

1981-01-01

15

Sex chromosomes and brain gender  

Microsoft Academic Search

In birds and mammals, differences in development between the sexes arise from the differential actions of genes that are encoded on the sex chromosomes. These genes are differentially represented in the cells of males and females, and have been selected for sex-specific roles. The brain is a sexually dimorphic organ and is also shaped by sex-specific selection pressures. Genes on

Arthur P. Arnold

2004-01-01

16

Disorders caused by chromosome abnormalities  

PubMed Central

Many human genetic disorders result from unbalanced chromosome abnormalities, in which there is a net gain or loss of genetic material. Such imbalances often disrupt large numbers of dosage-sensitive, developmentally important genes and result in specific and complex phenotypes. Alternately, some chromosomal syndromes may be caused by a deletion or duplication of a single gene with pleiotropic effects. Traditionally, chromosome abnormalities were identified by visual inspection of the chromosomes under a microscope. The use of molecular cytogenetic technologies, such as fluorescence in situ hybridization and microarrays, has allowed for the identification of cryptic or submicroscopic imbalances, which are not visible under the light microscope. Microarrays have allowed for the identification of numerous new syndromes through a genotype-first approach in which patients with the same or overlapping genomic alterations are identified and then the phenotypes are described. Because many chromosomal alterations are large and encompass numerous genes, the ascertainment of individuals with overlapping deletions and varying clinical features may allow researchers to narrow the region in which to search for candidate genes.

Theisen, Aaron; Shaffer, Lisa G

2010-01-01

17

Advances in Understanding Paternally Transmitted Chromosomal Abnormalities.  

National Technical Information Service (NTIS)

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 abnorma...

F. Marchetti E. Sloter A. J. Wyrobek

2002-01-01

18

Chromosome abnormalities in Indonesian patients with short stature  

PubMed Central

Background Short stature is associated with several disorders including wide variations of chromosomal disorders and single gene disorders. The objective of this report is to present the cytogenetic findings in Indonesian patients with short stature. Methods G-banding and interphase/metaphase FISH were performed on short stature patients with and without other clinical features who were referred by clinicians all over Indonesia to our laboratory during the year 2003–2009. Results The results of chromosomal analysis of ninety seven patients (mean age: 10.7 years old) were collected. The group of patients with other clinical features showed sex chromosome abnormalities in 45% (18/40) and autosomal abnormalities in 10% (4/40), whereas those with short stature only, 42.1% (24/57) had sex chromosome abnormalities and 1.75% (1/57) had autosomal abnormalities. The autosomal chromosomal abnormalities involved mostly subtelomeric regions. Results discrepancies between karyotype and FISH were found in 10 patients, including detection of low-level monosomy X mosaicism in 6 patients with normal karyotype, and detection of mosaic aneuploidy chromosome 18 in 1 patient with 45,XX,rob(13;14)(q10;q10). Statistical analysis showed no significant association between the groups and the type of chromosomal abnormalities. Conclusion Chromosome abnormalities account for about 50% of the short stature patients. Wide variations of both sex and autosomal chromosomes abnormalities were detected in the study. Since three out of five patients had autosomal structural abnormalities involving the subtelomeric regions, thus in the future, subtelomeric FISH or even a more sensitive method such as genomic/SNP microarray is needed to confirm deletions of subtelomeric regions of chromosome 9, 11 and 18. Low-level mosaicism in normal karyotype patients indicates interphase FISH need to be routinely carried out in short stature patients as an adjunct to karyotyping.

2012-01-01

19

Sex chromosomes and human growth  

Microsoft Academic Search

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

Lassi Alvesalo

1997-01-01

20

Sex chromosome polymorphism in guppies.  

PubMed

Sex chromosomes differ from autosomes by dissimilar gene content and, at a more advanced stage of their evolution, also in structure and size. This is driven by the divergence of the Y or W from their counterparts, X and Z, due to reduced recombination and the resulting degeneration as well as the accumulation of sex-specific and sexually antagonistic genes. A paradigmatic example for Y-chromosome evolution is found in guppies. In these fishes, conflicting data exist for a morphological and molecular differentiation of sex chromosomes. Using molecular probes and the previously established linkage map, we performed a cytogenetic analysis of sex chromosomes. We show that the Y chromosome has a very large pseudoautosomal region, which is followed by a heterochromatin block (HCY) separating the subtelomeric male-specific region from the rest of the chromosome. Interestingly, the size of the HCY is highly variable between individuals from different population. The largest HCY was found in one population of Poecilia wingei, making the Y almost double the size of the X and the largest chromosome of the complement. Comparative analysis revealed that the Y chromosomes of different guppy species are homologous and share the same structure and organization. The observed size differences are explained by an expansion of the HCY, which is due to increased amounts of repetitive DNA. In one population, we observed also a polymorphism of the X chromosome. We suggest that sex chromosome-linked color patterns and other sexually selected genes are important for maintaining the observed structural polymorphism of sex chromosomes. PMID:24676866

Nanda, Indrajit; Schories, Susanne; Tripathi, Namita; Dreyer, Christine; Haaf, Thomas; Schmid, Michael; Schartl, Manfred

2014-08-01

21

Sex Chromosomes and Sex Determination in Lepidoptera  

Microsoft Academic Search

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.

W. Traut; K. Sahara; F. Marec

2007-01-01

22

Schizophrenia and sex chromosome anomalies.  

PubMed

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 procedure. In this article, we review studies in which either complete karyotypes were determined for the whole sample or in which the presence of a Barr body in an individual was checked by full cytogenetic analysis. We also add two studies (of the former type) of our own--on a Swedish hospital cohort and a United States multiplex-schizophrenia family sample. These data, taken together, suggest that the sex chromosome aneuploidies, XXX and XXY, are increased in population of patients with schizophrenia, whereas too few subjects have been surveyed to determine whether an association also exists with XYY. Nevertheless, we conclude that this is consistent with a gene on the sex chromosomes having influence on the development of schizophrenia. A sex chromosome locus is compatible with an autosomal pattern of transmission if the gene is either pseudoautosomal (i.e., within the exchange region) or X-Y homologous (i.e., present in similar form in the nonrecombining regions of both X and Y chromosomes). PMID:7973466

DeLisi, L E; Friedrich, U; Wahlstrom, J; Boccio-Smith, A; Forsman, A; Eklund, K; Crow, T J

1994-01-01

23

Disorders of Sexual Development and Abnormal Early Development in Domestic Food-Producing Mammals: The Role of Chromosome Abnormalities, Environment and Stress Factors  

Microsoft Academic Search

The management of disorders of sexual development (DSD) in humans and domestic animals has been the subject of intense interest for decades. The association between abnormal chromosome constitutions and DSDs in domestic animals has been recorded since the beginnings of conventional cytogenetic analysis. Deviated karyotypes consisting of abnormal sex chromosome sets and\\/or the coexistence of cells with different sex chromosome

L. A. Favetta; D. A. F. Villagómez; L. Iannuzzi; G. Di Meo; A. Webb; S. Crain; W. A. King

2012-01-01

24

111. INHERITANCE OF SEX AND CROSSING OVER OF THE SEX CHROMOSOMES IN THE PLATYFISHl  

Microsoft Academic Search

AIDA (1921) has shown in the Japanese ricefield killifish, Aplocheilus, that the X and Y chromosomes of the male occasionally cross over. In 1930 he presented additional data on this, together with some interesting data involving aberrant sex ratios, which he interpreted as due to non- disjunction. In 1936 AIDA re-interpreted the abnormal sex ratios as due to sex reversal,

MYRON GORDON

25

Abnormal chromosomal arrangements in human oocytes.  

PubMed

Ninety-one human oocytes, lacking signs of fertilization 50 h after insemination in vitro, were investigated cytogenetically to assess the frequency and type of chromosomal abnormalities. Chromosome spreading permitted adequate karyotyping in 55 oocytes. Non-determined numerical aberrations occurred with the following frequencies: hypohaploidy, 10.9% (6/55), hyperhaploidy, 14.5% (8/55) and hyperdiploidy, 3.6% (2/55). Total aneuploidy occurred with a frequency of 29.1% and was observed in oocytes from 30 patients. No correlation was found between specific chromosomal aberrations and type of infertility, stimulation treatment or gonadotrophin levels. On the other hand, the frequency of aneuploidy was significantly higher (P less than 0.05) in patients greater than 35 years of age. Two chromosomal complements (3.6%) had structural rearrangements; one oocyte had both structural and numerical chromosomal abnormalities and the other had differently condensed regions on the long arms of three chromosomes from group C. The overall frequency of chromosomal aberrations was 32.7%. Only two samples contained an additional set of polar body chromosomes. Thirteen oocytes presented sperm chromosomes in an arrested stage of premature chromosome condensation of the G1 phase and four oocytes showed asynchronous condensation of pronuclear chromosomes. Finally, it was concluded that the high proportion of chromosomal aberrations observed in human oocytes may contribute significantly to abnormal embryonic development in vitro. PMID:2254403

Macas, E; Floersheim, Y; Hotz, E; Imthurn, B; Keller, P J; Walt, H

1990-08-01

26

Chromosomal Abnormalities in Couples with Reproductive Disorders  

Microsoft Academic Search

Aim: To determine the prevalence of chromosomal abnormalities in couples with reproductive disorders. Methods: A retrospective study was performed in 939 Mexican couples with reproductive disorders (542 with recurrent fetal loss, 356 with malformed\\/stillborn children, and 41 with sterility) whose karyotype was established on GTG-banded metaphases. Results: A chromosomal aberration was detected in one partner of 52 couples, including a

Juan Pablo Meza-Espinoza; Lilia Ortiz Anguiano; Horacio Rivera

2008-01-01

27

New Y chromosomes and early stages of sex chromosome differentiation: sex determination in Megaselia  

Microsoft Academic Search

The phorid fly Megaselia scalaris is a laboratory model for the turnover and early differentiation of sex chromosomes. Isolates from the field have an XY sex-determining\\u000a mechanism with chromosome pair 2 acting as X and Y chromosomes. The sex chromosomes are homomorphic but display early signs\\u000a of sex chromosome differentiation: a low level of molecular differences between X and Y.

Walther Traut

2010-01-01

28

Chromosome abnormalities in chronic active hepatitis  

PubMed Central

An investigation on human peripheral blood lymphocyte chromosomes in chronic active hepatitis was carried out. A higher percentage of chromatid and chromosome lesions was recorded in all patients studied as compared with control groups—normal individuals, healthy subjects who had suffered from acute viral hepatitis, patients with alcoholic liver disease, and patients with mechanical jaundice due to cancer. The possible origin of these abnormalities is discussed.

Stefanescu, D. T.; Moanga, M.; Teodorescu, M.; Brucher, J.

1972-01-01

29

Chromosomal abnormalities in patients with autism spectrum disorders from Taiwan.  

PubMed

Autism spectrum disorders (ASD) are childhood-onset neurodevelopmental disorders characterized by verbal communication impairments, social reciprocity deficits, and the presence of restricted interests and stereotyped behaviors. Genetic factors contribute to the incidence of ASD evidently. However, the genetic spectrum of ASD is highly heterogeneous. Chromosomal abnormalities contribute significantly to the genetic deficits of syndromic and non-syndromic ASD. In this study, we conducted karyotyping analysis in a sample of 500 patients (447 males, 53 females) with ASD from Taiwan, the largest cohort in Asia, to the best of our knowledge. We found three patients having sex chromosome aneuploidy, including two cases of 47, XXY and one case of 47, XYY. In addition, we detected a novel reciprocal chromosomal translocation between long arms of chromosomes 4 and 14, designated t(4;14)(q31.3;q24.1), in a patient with Asperger's disorder. This translocation was inherited from his unaffected father, suggesting it might not be pathogenic or it needs further hits to become pathogenic. In line with other studies, our study revealed that subjects with sex chromosomal aneuploidy are liable to neurodevelopmental disorders, including ASD, and conventional karyotyping analysis is still a useful tool in detecting chromosomal translocation in patients with ASD, given that array-based comparative genomic hybridization technology can provide better resolution in detecting copy number variations of genomic DNA. PMID:24132905

Liao, Hsiao-Mei; Gau, Susan Shur-Fen; Tsai, Wen-Che; Fang, Jye-Siung; Su, Ying-Cheng; Chou, Miao-Chun; Liu, Shih-Kai; Chou, Wen-Jiun; Wu, Yu-Yu; Chen, Chia-Hsiang

2013-10-01

30

XYY chromosome abnormality in sexual homicide perpetrators.  

PubMed

In a retrospective investigation of the court reports about sexual homicide perpetrators chromosome analysis had been carried out in 13 of 166 (7.8%) men. Three men (1.8%) with XYY chromosome abnormality were found. This rate is much higher than that found in unselected samples of prisoners (0.7-0.9%) or in the general population (0.01%). The three men had shown prepubescent abnormalities, school problems, and had suffered from physical abuse. The chromosome analysis in all cases had been carried out in connection with the forensic psychiatric court report due to the sexual homicide. However, two men had earlier psychiatric referrals. All were diagnosed as sexual sadistic, showed a psychopathic syndrome or psychopathy according to the Psychopathy Checklist-Revised [Hare RD, 1991, The Hare Psychopathy Checklist-Revised, Toronto, Ontario, Canada: Multi-Health Systems]. Two were multiple murderers. Especially forensic psychiatrists should be vigilant of the possibility of XYY chromosome abnormalities in sexual offenders. PMID:16389589

Briken, Peer; Habermann, Niels; Berner, Wolfgang; Hill, Andreas

2006-03-01

31

Evolution of Sex Chromosomes in Insects  

PubMed Central

Sex chromosomes have many unusual features relative to autosomes. Y (or W) chromosomes lack genetic recombination, are male- (female-) limited, and show an abundance of genetically inert heterochromatic DNA but contain few functional genes. X (or Z) chromosomes also show sex-biased transmission (i.e., X chromosomes show female-biased and Z-chromosomes show male-biased inheritance) and are hemizygous in the heterogametic sex. Their unusual ploidy level and pattern of inheritance imply that sex chromosomes play a unique role in many biological processes and phenomena, including sex determination, epigenetic chromosome-wide regulation of gene expression, the distribution of genes in the genome, genomic conflict, local adaptation, and speciation. The vast diversity of sex chromosome systems in insects—ranging from the classical male heterogametic XY system in Drosophila to ZW systems in Lepidoptera or mobile genes determining sex as found in house flies—implies that insects can serve as unique model systems to study various functional and evolutionary aspects of these different processes.

Kaiser, Vera B.; Bachtrog, Doris

2011-01-01

32

A specific chromosomal abnormality in rhabdomyosarcoma  

Microsoft Academic Search

A specific chromosomal abnormality, t(2;13)(q35;q14), was discovered in five cases of advanced rhabdomyosarcoma. It was identified directly in cells that had metastasized from bone marrow in one patient and in xenografts derived from the tumors of four other patients. The translocation was not restricted by histologic subtype, but was found in cases classified as alveolar, undifferentiated, or embryonal. Cytogenetic hallmarks

E. C. Douglass; M. Valentine; E. Etcubanas; D. Parham; B. L. Webber; P. J. Houghton; A. A. Green

1987-01-01

33

Autosomal Chromosome Abnormality: A Cause of Birth Defects.  

ERIC Educational Resources Information Center

Intended for parents and professionals, the book explains chromosome abnormalities in lay terms and discusses the relationship of specific conditions to birth defects. Chromosomal abnormalities are defined and factors in diagnosis and recurrence are discussed. Normal chromosome reproduction processes are covered while such numerical abnormalities

Plumridge, Diane

34

SEX CHROMOSOME ACTIVATION DURING SPERMATOGENESIS  

Microsoft Academic Search

INACTIVATION of chromosomal elements is a process which takes place in various organisms, cell types, and cell cycle stages. The reasons for chromosome inactivation, which is superimposed on the more specific level of gene control, are different for the various systems. Dosage compensation in female mammals us. mitotic chromosome shut-off are the extreme cases. Since in many systems every chromosome

E. LIFSCHYTZ

1974-01-01

35

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

ERIC Educational Resources Information Center

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…

Walzer, Stanley

1985-01-01

36

Prenatal diagnosis of sex chromosome aneuploidies and disorders of sex development - a retrospective analysis of 11-year data.  

PubMed

Abstract Objective: Analysis of prenatally diagnosed sex chromosome aneuploidies and disorders of sex development (DSDs). Methods: This study includes a retrospective data analysis of 46 prenatally detected sex chromosome aneuploidies and one case of 46,XY DSD diagnosed during an 11-year period (2002-2012) at our department. Results: Of the 46 sex chromosome aneuploidies, 29 cases (63.0%) were in the group of a selected population of women according to abnormal first-/second-trimester ultrasound and 17 (37.0%) cases in an unselected population of women who underwent fetal karyotyping because of advanced maternal age. The most common aneuploidy was Turner syndrome in full and mosaic form (50%). Complete androgen insensitivity syndrome was diagnosed in the case of 46,XY DSD. Conclusions: Sex chromosome aneuploidies must be taken into consideration if, in the first or second trimester, abnormalities are revealed on ultrasound, mainly Turner syndrome in full or mosaic form and 47,XYY. PMID:24445234

Vlatkovic, Ivanka Bekavac; Hafner, Tomislav; Miskovic, Berivoj; Vicic, Ana; Poljak, Borna; Stipoljev, Feodora

2014-07-01

37

Meiotic inactivation of sex chromosomes in mammals  

Microsoft Academic Search

During meiosis, heteromorphic mammalian X and Y chromosomes in males undergo transcription silencing and form a compact structure,\\u000a the XY body, containing specific modifications of the chromatin. In this review, we consider the dynamics of sex chromosome\\u000a inactivation and discuss the suggestion that the paternally inherited X-chromosome preserves inactivated state in zygote.\\u000a This state results from meiotic silencing and is

E. A. Vaskova; S. V. Pavlova; A. I. Shevchenko; S. M. Zakian

2010-01-01

38

Sex-specific chromosome instability in early human development.  

PubMed

The predominance of females segregating chromosome aberrations to their offspring has been explained mostly by selection disadvantage of unbalanced products of spermatogenesis. However, analysis of data from the literature supports the idea that somatic cells of early female embryos are similar to female germ cells in that they are prone to malsegregation. The goal of this study was to compare the sex ratio (male to female ratio) of carriers of presumably mitotic-occurring chromosome abnormalities to identify any sex biases. In examining the literature, we found a female prevalence in cases of mosaicism associated with uniparental disomy (UPD) (26 male individuals/conceptions and 45 female individuals/conceptions, sex ratio is 0.58, significantly different from 1.06 in newborn population, P = 0.0292). This predominance was highest at gestational age <16 week (8 male and 22 female conceptuses, sex ratio is 0.36, significantly different from expected figure of 1.28, P = 0.0025), which diminished at later stages of fetal development indicating potential correction of trisomies predominantly in females. There is a threefold prevalence of 46,XX/45,X mosaics over 46,XY/45,X mosaics in prenatally diagnosed cases, which also suggests a gender-specific postzygotic chromosome loss. The male prevalence in Prader-Willi syndrome with maternal UPD of chromosome 15 also can be explained by sex-specific trisomy correction, with predominant loss of a maternal chromosome causing biparental inheritance and therefore, complete correction of trisomy in females (without UPD). Finally, there is a female predominance in carriers of chromosome rearrangement with pericentromere break (mosaicism for Robertsonian translocation/isochromosome, centric fission, nonacrocentric isochromosome, and whole arm rearrangement), in both prenatal (21 males and 36 females, sex ratio is 0.58, P < 0.0184) and postnatal ill-defined cases (14 males and 35 females, sex ratio is 0.40, P = 0.001). Thus, the findings presented in this paper suggest that, in addition to reduction in male fertility, and to probable selection against abnormal cell line(s), there are two mechanisms that contribute to female preponderance among carriers of mosaicism: sex-specific chromosome loss and sex-specific centromere instability. The data obtained suggest that females may have gonadal mosaicism for aneuploidies and structural rearrangements more often than males. This may lead to the maternal origin bias in offspring with trisomies or structural rearrangements. PMID:16001445

Kovaleva, Natalia V

2005-08-01

39

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

ERIC Educational Resources Information Center

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)

And Others; Goh, Kong-oo

1978-01-01

40

Human Male Meiotic Sex Chromosome Inactivation  

Microsoft Academic Search

In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as

Marieke de Vries; Sanne Vosters; Gerard Merkx; Kathleen DHauwers; Derick G. Wansink; Liliana Ramos; Peter de Boer

2012-01-01

41

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

PubMed Central

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.

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

2011-01-01

42

Chromosomal abnormalities in spontaneous abortion after assisted reproductive treatment  

Microsoft Academic Search

BACKGROUND: We evaluated cytogenetic results occurring with first trimester pregnancy loss, and assessed the type and frequency of chromosomal abnormalities after assisted reproductive treatment (ART) and compared them with a control group. We also compared the rate of chromosomal abnormalities according to infertility causes in ICSI group. METHODS: A retrospective cohort analysis was made of all patients who were referred

Ji Won Kim; Woo Sik Lee; Tae Ki Yoon; Hyun Ha Seok; Jung Hyun Cho; You Shin Kim; Sang Woo Lyu; Sung Han Shim

2010-01-01

43

Chromosome Imbalance as a Driver of Sex Disparity in Disease  

PubMed Central

It has long been recognized that men and women exhibit different risks for diverse disorders ranging from metabolic to autoimmune diseases. However, the underlying causes of these disparities remain obscure. Analysis of patients with chromosomal abnormalities, including Turner syndrome (45X) and Klinefelter syndrome (47XXY), has highlighted the importance of X-linked gene dosage as a contributing factor for disease susceptibility. Escape from X-inactivation and X-linked imprinting can result in transcriptional differences between normal men and women as well as in patients with sex chromosome abnormalities. Animal models support a role for X-linked gene dosage in disease with O-linked N-acetylglucosamine transferase (OGT) emerging as a prime candidate for a pleiotropic effector. OGT encodes a highly regulated nutrient-sensing epigenetic modifier with established links to immunity, metabolism and development.

Abramowitz, Lara K.; Olivier-Van Stichelen, Stephanie; Hanover, John A.

2014-01-01

44

Human Male Meiotic Sex Chromosome Inactivation  

PubMed Central

In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as meiotic sex chromosome inactivation (MSCI), which has been studied best in mice. Post-meiotically this repression is largely maintained. Disturbance of MSCI in mice leads to harmful X,Y gene expression, eventuating in spermatocyte death and sperm heterogeneity. Sperm heterogeneity is a characteristic of the human male. For this reason we were interested in the efficiency of MSCI in human primary spermatocytes. We investigated MSCI in pachytene spermatocytes of seven probands: four infertile men and three fertile controls, using direct and indirect in situ methods. A considerable degree of variation in the degree of MSCI was detected, both between and within probands. Moreover, in post-meiotic stages this variation was observed as well, indicating survival of spermatocytes with incompletely inactivated sex chromosomes. Furthermore, we investigated the presence of H3K9me3 posttranslational modifications on the X and Y chromatin. Contrary to constitutive centromeric heterochromatin, this heterochromatin marker did not specifically accumulate on the XY body, with the exception of the heterochromatic part of the Y chromosome. This may reflect the lower degree of MSCI in man compared to mouse. These results point at relaxation of MSCI, which can be explained by genetic changes in sex chromosome composition during evolution and candidates as a mechanism behind human sperm heterogeneity.

de Vries, Marieke; Vosters, Sanne; Merkx, Gerard; D'Hauwers, Kathleen; Wansink, Derick G.; Ramos, Liliana; de Boer, Peter

2012-01-01

45

Comparative Analysis by Chromosome Painting of the Sex Chromosomes in Arvicolid Rodents  

Microsoft Academic Search

Sex chromosome evolution in mammals has been extensively investigated through chromosome-painting analyses. In some rodent species from the subfamily Arvicolinae the sex chromosomes contain remarkable features such as giant size, a consequence of heterochromatic enlargement, or asynaptic behaviour during male meiosis. Here, we have made a comparative study of the sex chromosomes in 6 arvicolid species using different probes from

M. J. Acosta; I. Romero-Fernández; A. Sánchez; J. A. Marchal

2011-01-01

46

Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)  

Microsoft Academic Search

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

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

2009-01-01

47

Assessment of numerical chromosomal abnormalities of the sperms before and after radiotherapy in seminoma patient  

PubMed Central

Objective: To assess numerical sex chromosomal abnormalities of the sperms before and after radiotherapy in seminoma patients and to evaluate their reproduction risks. Methods: Three color Fluorescence in situ hybridization (FISH) was performed on sperms harvested from one seminoma patient before and after radiotherapy and before surgery. The numerical sex chromosomal abnormalities were compared. Results: The ratio of 18-X and 18-Y sperm cells among the counted 40944 ones was close to 1:1 at three time points. The incidence of chromosome aneuploidy and diploid rate (18, X, Y) significantly increased after radiotherapy when compared with that before surgery and before radiotherapy. However, no significance was observed in the aneuploid and diploid rate between pre-operation group and pre-radiotherapy (post-operation) group except for the 18-YY karyotype (0.095% vs 0.026%, p<0.05). Conclusion: Our study shows increased incidence of numerical sex chromosomal abnormalities and high risk for reproductive and genetic diseases in patients treated with radiotherapy. Three colored FISH test is recommended to evaluate the rate of numerical chromosomal abnormalities; PGD and prenatal diagnosis are advised to improve the likelihood of a successful pregnancy.

Le, Wei; Huang, Shengsong; Gui, Yaping; Luo, Huarong; Wu, Denglong; Feng, Huailiang; Zhang, Jinfu

2014-01-01

48

FISH studies of chromosome abnormalities in germ cells and its relevance in reproductive counseling.  

PubMed

Chromosome abnormalities are one of the major causes of human infertility. In infertile males, abnormal karyotypes are more frequent than in the general population. Furthermore, meiotic disorders affecting the germ cell-line have been observed in men with normal somatic karyotypes consulting for infertility. In both cases, the production of unbalanced spermatozoa has been demonstrated. Basically addressed to establish reproductive risks, fluorescence in situ hybridization (FISH) on decondensed sperm heads has become the most frequently used method to evaluate the chromosomal constitution of spermatozoa in carriers of numerical sex chromosome abnormalities, carriers of structural chromosome reorganizations and infertile males with normal karyotype. The aim of this review is to present updated figures of the information obtained through sperm FISH studies with an emphasis on its clinical significance. Furthermore, the incorporation of novel FISH-based techniques (Multiplex-FISH; Multi-FISH) in male infertility studies is also discussed. PMID:16110350

Sarrate, Zaida; Blanco, Joan; Anton, Ester; Egozcue, Susana; Egozcue, Josep; Vidal, Francesca

2005-09-01

49

Current status of chromosomal abnormalities in mouse embryonic stem cell lines used in Japan.  

PubMed

We performed chromosomal analysis on 540 mouse embryonic stem (ES) cell lines obtained during 2001 to 2004 from 20 institutions in Japan. Overall, 66.5% of the ES cell lines showed normal chromosomal numbers, but 15.9%, 9.1%, and 2.8% showed modal chromosomal numbers of 41, 42, and 39, respectively. When we karyotyped 88 ES cell lines selected arbitrarily from the 540 lines, 53 (60.2%) showed normal diploid karyotypes; the sex chromosome constitution of 52 lines was XY, with the remaining 1 being XX. Among 35 ES cell lines showing abnormal karyotypes, trisomy of chromosome 8 (41, XY, +8) was dominant (51.4%), 14.3% had trisomy 8 with loss of one sex chromosome (40, XO, +8), and 11.4% had trisomy 8 together with trisomy 11 (42, XY, +8, +11). Karyotypic abnormalities including trisomy 8 and trisomy 11 occurred in 88.6% and 17.1% of ES cell lines, respectively. The XO sex chromosome constitution was observed in 25.7% of all abnormal ES cell lines. Of the 88 selected ES cell lines, 60 lines were established from strain 129 animals, 17 from F1 progeny of C57BL/6J x CBA (called TT2 in this study), and 11 from C57BL/6J mice. Normal diploid karyotypes were observed in 58.3% of lines derived from 129, 58.8% of those from TT2, and 72.7% of C57BL/6J. The relatively high incidence of abnormalities in chromosomal number and karyotype in ES cell lines used in Japan suggests the importance of chromosomal analysis of ES cells for successful establishment of new animal models through germline transmission. PMID:16521857

Sugawara, Ayako; Goto, Kazuo; Sotomaru, Yusuke; Sofuni, Toshio; Ito, Toshio

2006-02-01

50

Abnormalities of the corpus callosum in nonpsychotic children with chromosome 22q11 deletion syndrome  

Microsoft Academic Search

Chromosome 22q11 deletion syndrome (22q11DS) is associated with elevated rates of schizophrenia and other psychoses in adulthood. Childhood morphologic brain abnormalities are frequently reported, but the significance of these and their relationship to the development of schizophrenia are unclear. We sought to delineate midline neuroanatomical abnormalities in nonpsychotic children with 22q11DS and their age- and sex-matched controls and compare these

Vandana Shashi; Srirangam Muddasani; Cesar C. Santos; Margaret N. Berry; Thomas R. Kwapil; Eve Lewandowski; Matcheri S Keshavan

2004-01-01

51

The origin of cytologically unidentifiable chromosome abnormalities: six cases ascertained by targeted chromosome-band painting  

Microsoft Academic Search

De novo chromosome structural abnormalities cannot always be diagnosed by the use of standard cytogenetic techniques. We applied a previously developed chromosome-band-specific painting method to the diagnosis of such rearrangements. The diagnostic procedures consisted of microdissection of an aberrant chromosomal region of a given patient, polymerase chain reaction (PCR) amplification of the dissected chromosomal DNA, and subsequent competitive fluorescence in

T. Ohta; T. Tohma; H. Soejima; Y. Fukushima; T. Nagai; K. Yoshiura; Y. Jinno; N. Niikawa

1993-01-01

52

Psychiatric syndromes in individuals with chromosome 18 abnormalities.  

PubMed

Chromosome 18 abnormalities are associated with a range of physical abnormalities such as short stature and hearing impairments. Psychiatric manifestations have also been observed. This study focuses on the presentations of psychiatric syndromes as they relate to specific chromosomal abnormalities of chromosome 18. Twenty-five subjects (13 with an 18q deletion, 9 with 18p tetrasomy, and 3 with an 18p deletion), were interviewed by psychiatrists (blind to specific chromosomal abnormality) using the DIGS (subjects 18 and older) or KSADS-PL (subjects under 18). A consensus best estimation diagnostic process was employed to determine psychiatric syndromes. Oligonucleotide Array Comparative Genomic Hybridization (Agilent Technologies) was utilized to define specific regions of chromosome 18 that were deleted or duplicated. These data were further analyzed to determine critical regions of the chromosome as they relate to phenotypic manifestations in these subjects. 58.3% of the chromosome 18q- deletion subjects had depressive symptoms, 58.3% had anxiety symptoms, 25% had manic symptoms, and 25% had psychotic symptoms. 66.6% of the chromosome 18p- deletion subjects had anxiety symptoms, and none had depressive, manic, or psychotic symptoms. Fifty percent of the chromosome 18p tetrasomy subjects had anxiety symptoms, 12.5% had psychotic symptoms, and 12.5% had a mood disorder. All three chromosomal disorders were associated with high anxiety rates. Psychotic, manic and depressive disorders were seen mostly in 18q- subjects and this may be helpful in narrowing regions for candidate genes for these psychiatric conditions. PMID:19927307

Zavala, Juan; Ramirez, Mercedes; Medina, Rolando; Heard, Patricia; Carter, Erika; Crandall, AnaLisa; Hale, Daniel; Cody, Jannine; Escamilla, Michael

2010-04-01

53

Evidence of a neo-sex chromosome in birds  

PubMed Central

Neo-sex chromosomes often originate from sex chromosome–autosome fusions and constitute an important basis for the study of gene degeneration and expression in a sex chromosomal context. Neo-sex chromosomes are known from many animal and plant lineages, but have not been reported in birds, a group in which genome organization seems particularly stable. Following indications of sex linkage and unexpected sex-biased gene expression in warblers (Sylvioidea; Passeriformes), we have conducted an extensive marker analysis targeting 31 orthologues of loci on zebra finch chromosome 4a in five species, representative of independent branches of Passerida. We identified a region of sex linkage covering approximately the first half (10?Mb) of chromosome 4a, and associated to both Z and W chromosomes, in three Sylvioidea passerine species. Linkage analysis in an extended pedigree of one species additionally confirmed the association between this part of chromosome 4a and the Z chromosome. Markers located between 10 and 21?Mb of chromosome 4a showed no signs of sex linkage, suggesting that only half of the chromosome was involved in this transition. No sex linkage was observed in non-Sylvioidea passerines, indicating that the neo-sex chromosome arose at the base of the Sylvioidea branch of the avian phylogeny, at 47.4–37.6 millions years ago (MYA), substantially later than the ancestral sex chromosomes (150 MYA). We hypothesize that the gene content of chromosome 4a might be relevant in its transition to a sex chromosome, based on the presence of genes (for example, the androgen receptor) that could offer a selective advantage when associated to Z-linked sex determination loci.

Pala, I; Naurin, S; Stervander, M; Hasselquist, D; Bensch, S; Hansson, B

2012-01-01

54

Comparative chromosome mapping of sex-linked genes and identification of sex chromosomal rearrangements in the Japanese wrinkled frog ( Rana rugosa , Ranidae) with ZW and XY sex chromosome systems  

Microsoft Academic Search

There are regional variations of sex chromosome morphologies in the Japanese wrinkled frog, Rana rugosa (2n?=?26): heterogametic ZZ\\/ZW-type and XX\\/XY-type sex chromosomes, and two different types of homomorphic sex chromosomes.\\u000a To search for homology between the ZW and XY sex chromosomes and the chromosome rearrangements that have occurred during sex\\u000a chromosomal differentiation in R. rugosa, we performed chromosome mapping of

Yoshinobu Uno; Chizuko Nishida; Yuki Oshima; Satoshi Yokoyama; Ikuo Miura; Yoichi Matsuda; Masahisa Nakamura

2008-01-01

55

Steps in the evolution of heteromorphic sex chromosomes  

Microsoft Academic Search

We review some recently published results on sex chromosomes in a diversity of species. We focus on several fish and some plants whose sex chromosomes appear to be ‘young’, as only parts of the chromosome are nonrecombining, while the rest is pseudoautosomal. However, the age of these systems is not yet very clear. Even without knowing what proportions of their

D Charlesworth; B Charlesworth; G Marais

2005-01-01

56

Paternity uncertainty overrides sex chromosome selection for preferential grandparenting  

Microsoft Academic Search

With respect to autosomal genes, a grandparent is equally related to male and female grandchildren. Because males are heterozygous for sex chromosomes, however, grandparents are asymmetrically related to male and female grandchildren via the sex chromosomes. For example, the Y chromosome from the paternal grandfather passes directly down to grandsons. This asymmetry leads to a prediction that genes on the

Elizabeth R. Chrastil; Wayne M. Getz; Harald A. Euler; Philip T. Starks

2006-01-01

57

Trisomy 13: A New Recurring Chromosome Abnormality in Acute Leukemia  

Microsoft Academic Search

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,

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

58

Chromosomal abnormalities in human breast cancer  

Microsoft Academic Search

This review emphasizes cytogenetic changes and DNA analyses by Southern blot in primary breast tumors, rather than metastases, established cell lines, and pleural effusions. The data suggests that the most frequently altered chromosomes and chromosome regions are 1p, 1q, 2q, 3p, 5, 6q, 8p, 8q, 11p, 11q, 12, 13q, 14q, 16, 17p, and 17q. Changes on 8q, 11p, 11q, 13q,

Wendy M. Mars; Grady F. Saunders

1990-01-01

59

Meiotic Sex Chromosome Inactivation in Drosophila  

PubMed Central

In several different taxa, there is indubitable evidence of transcriptional silencing of the X and Y chromosomes in male meiotic cells of spermatogenesis. However, the so called meiotic sex chromosome inactivation (MSCI) has been recently a hot bed for debate in Drosophila melanogaster. This review covers cytological and genetic observations, data from transgenic constructs with testis-specific promoters, global expression profiles obtained from mutant, wild-type, larvae and adult testes as well as from cells of different stages of spermatogenesis. There is no dispute on that D. melanogaster spermatogenesis presents a down-regulation of X chromosome that does not result from the lack of dosage compensation. However, the issue is currently focused on the level of reduction of X-linked expression, the precise time it occurs and how many genes are affected. The deep examination of data and experiments in this review exposes the limitations intrinsic to the methods of studying MSCI in D. melanogaster. The current methods do not allow us to affirm anything else than the X chromosome down-regulation in meiosis (MSCI). Therefore, conclusion about level, degree or precise timing is inadequate until new approaches are implemented to know the details of MSCI or other processes involved for D. melanogaster model.

Vibranovski, Maria D.

2014-01-01

60

Conserved sex chromosomes across adaptively radiated anolis lizards.  

PubMed

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

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

2014-07-01

61

A bird's-eye view of sex chromosome dosage compensation.  

PubMed

Intensive study of a few genetically tractable species with XX/XY sex chromosomes has produced generalizations about the process of sex chromosome dosage compensation that do not fare well when applied to ZZ/ZW sex chromosome systems, such as those in birds. The inherent sexual imbalance in dose of sex chromosome genes has led to the evolution of sex-chromosome-wide mechanisms for balancing gene dosage between the sexes and relative to autosomal genes. Recent advances in our knowledge of avian genomes have led to a reexamination of sex-specific dosage compensation (SSDC) in birds, which is less effective than in known XX/XY systems. Insights about the mechanisms of SSDC in birds also suggest similarities to and differences from those in XX/XY species. Birds are thus offering new opportunities for studying dosage compensation in a ZZ/ZW system, which should shed light on the evolution of SSDC more broadly. PMID:18489256

Arnold, Arthur P; Itoh, Yuichiro; Melamed, Esther

2008-01-01

62

Chromosome abnormality incidence in fetuses with cerebral ventriculomegaly.  

PubMed

Abstract Ventriculomegaly (VM) is a marker of aneuploidy and warrants a detailed examination of fetal anatomy. Chromosomal abnormalities worsen the fetal and neonatal prognosis significantly and karyotyping of fetuses is critically important when accompanying anomalies are detected. Here, we report the genetic results of 140 fetuses with isolated and non-isolated VM detected during a second trimester ultrasound examination followed by invasive in utero diagnostic procedures for karyotyping. VM was diagnosed in seven (5%) fetuses with abnormal karyotype and the chromosomal abnormality incidence was higher in severe VM (6.8%) than mild (4.2%). Higher chromosomal abnormality rates were detected when VM was isolated (8.6%), rather than associated with any anomaly (3.8%). These results suggest that karyotype analysis should be offered to all patients with any degree of VM, regardless of its association with structural anomalies. PMID:24678817

Gezer, C; Ekin, A; Ozeren, M; Taner, C E; Ozer, O; Koc, A; Bilgin, M; Gezer, N S

2014-07-01

63

Detection of Chromosomal Abnormalities in Human Sperm.  

National Technical Information Service (NTIS)

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...

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

1985-01-01

64

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

PubMed Central

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.

2013-01-01

65

[Detection of chromosomal abnormalities using cordocentesis].  

PubMed

Four cases of cytogenetic prenatal diagnosis of fetuses with chromosomal aberrations are presented: (1) the Patau syndrome; (2) and (4) the Down syndrome; (3) the Klinefelter syndrome. Cordocentesis has been shown to be expedient for rapid and accurate determination of fetus karyotype. Indicative for cytogenetic examination were ultrasonic data, maternal age, the values of AFP, HGG and nonconjugated estreol in maternal serum. Comparison of ultrasonic examination of fetuses with the data on abortus autotopsia was undertaken. The results demonstrate importance of ultrasonic, cytogenetic, biochemical and morphological research in prenatal malformation diagnosis. PMID:1722186

Zolotukhina, T V; Kuznetsov, M I; Kostiuk, E V; Shilova, N V; Solonichenko, V G

1991-08-01

66

Disorders of sexual development and abnormal early development in domestic food-producing mammals: the role of chromosome abnormalities, environment and stress factors.  

PubMed

The management of disorders of sexual development (DSD) in humans and domestic animals has been the subject of intense interest for decades. The association between abnormal chromosome constitutions and DSDs in domestic animals has been recorded since the beginnings of conventional cytogenetic analysis. Deviated karyotypes consisting of abnormal sex chromosome sets and/or the coexistence of cells with different sex chromosome constitutions in an individual seem to be the main causes of anomalies of sex determination and sex differentiation. In recent years, a growing interest has developed around the environmental insults, such as endocrine-disrupting compounds (EDC) and heat stressors, which affect fertility, early embryonic development and, in some instances, directly the sex ratio and/or the development of 1 specific sex versus the other. A variety of chemical compounds present in the environment at low doses has been shown to have major effects on the reproductive functions in human and domestic animals following prolonged exposure. In this review, we present an overview of congenital/chromosomal factors that are responsible for the DSDs and link them and the lack of proper embryonic development to environmental factors that are becoming a major global concern. PMID:22024933

Favetta, L A; Villagómez, D A F; Iannuzzi, L; Di Meo, G; Webb, A; Crain, S; King, W A

2012-01-01

67

Human postmeiotic sex chromatin and its impact on sex chromosome evolution  

PubMed Central

Sex chromosome inactivation is essential epigenetic programming in male germ cells. However, it remains largely unclear how epigenetic silencing of sex chromosomes impacts the evolution of the mammalian genome. Here we demonstrate that male sex chromosome inactivation is highly conserved between humans and mice and has an impact on the genetic evolution of human sex chromosomes. We show that, in humans, sex chromosome inactivation established during meiosis is maintained into spermatids with the silent compartment postmeiotic sex chromatin (PMSC). Human PMSC is illuminated with epigenetic modifications such as trimethylated lysine 9 of histone H3 and heterochromatin proteins CBX1 and CBX3, which implicate a conserved mechanism underlying the maintenance of sex chromosome inactivation in mammals. Furthermore, our analyses suggest that male sex chromosome inactivation has impacted multiple aspects of the evolutionary history of mammalian sex chromosomes: amplification of copy number, retrotranspositions, acquisition of de novo genes, and acquisition of different expression profiles. Most strikingly, profiles of escape genes from postmeiotic silencing diverge significantly between humans and mice. Escape genes exhibit higher rates of amino acid changes compared with non-escape genes, suggesting that they are beneficial for reproductive fitness and may allow mammals to cope with conserved postmeiotic silencing during the evolutionary past. Taken together, we propose that the epigenetic silencing mechanism impacts the genetic evolution of sex chromosomes and contributed to speciation and reproductive diversity in mammals.

Sin, Ho-Su; Ichijima, Yosuke; Koh, Eitetsu; Namiki, Mikio; Namekawa, Satoshi H.

2012-01-01

68

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

PubMed

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

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

2014-03-01

69

Homologous sex chromosomes in three deeply divergent anuran species.  

PubMed

Comparative genomic studies are revealing that, in sharp contrast with the strong stability found in birds and mammals, sex determination mechanisms are surprisingly labile in cold-blooded vertebrates, with frequent transitions between different pairs of sex chromosomes. It was recently suggested that, in context of this high turnover, some chromosome pairs might be more likely than others to be co-opted as sex chromosomes. Empirical support, however, is still very limited. Here we show that sex-linked markers from three highly divergent groups of anurans map to Xenopus tropicalis scaffold 1, a large part of which is homologous to the avian sex chromosome. Accordingly, the bird sex determination gene DMRT1, known to play a key role in sex differentiation across many animal lineages, is sex linked in all three groups. Our data provide strong support for the idea that some chromosome pairs are more likely than others to be co-opted as sex chromosomes because they harbor key genes from the sex determination pathway. PMID:23888863

Brelsford, Alan; Stöck, Matthias; Betto-Colliard, Caroline; Dubey, Sylvain; Dufresnes, Christophe; Jourdan-Pineau, Hélène; Rodrigues, Nicolas; Savary, Romain; Sermier, Roberto; Perrin, Nicolas

2013-08-01

70

Environmental Exposure to Polychlorinated Biphenyls and p,p?-DDE and Sperm Sex-Chromosome Disomy  

PubMed Central

Background: Chromosomal abnormalities contribute substantially to reproductive problems, but the role of environmental risk factors has received little attention. Objectives: We evaluated the association of polychlorinated biphenyl (PCB) and dichlorodiphenyldichloroethylene (p,p´-DDE) exposures with sperm sex-chromosome disomy. Methods: We conducted a cross-sectional study of 192 men from subfertile couples. We used multiprobe fluorescence in situ hybridization (FISH) for chromosomes X, Y, and 18 to determine XX, YY, XY, and total sex-chromosome disomy in sperm nuclei. Serum was analyzed for concentrations of 57 PCB congeners and p,p´-DDE. Poisson regression models were used to calculate incidence rate ratios (IRRs) for disomy by exposure quartiles, controlling for demographic characteristics and semen parameters. Results: The median percent disomy was 0.3 for XX and YY, 0.9 for XY, and 1.6 for total sex-chromosome disomy. We observed a significant trend of increasing IRRs for increasing quartiles of p,p´-DDE in XX, XY, and total sex-chromosome disomy, and a significant trend of increasing IRRs for increasing quartiles of PCBs for XY and total sex-chromosome disomy; however, there was a significant inverse association for XX disomy. Conclusions: Our findings suggest that exposure to p,p´-DDE may be associated with increased rates of XX, XY, and total sex-chromosome disomy, whereas exposure to PCBs may be associated with increased rates of YY, XY, and total sex-chromosome disomy. In addition, we observed an inverse association between increased exposure to PCBs and XX disomy. Further work is needed to confirm these findings.

McAuliffe, Megan E.; Williams, Paige L.; Korrick, Susan A.; Altshul, Larisa M.

2011-01-01

71

Abnormal chromosome behavior in human oocytes which remained unfertilized during human in vitro fertilization  

Microsoft Academic Search

Chromosomal abnormalities and abnormal embryonic development have previously been observed after human in vitro fertilization (IVF). Chromosomal abnormalities may arise not only after fertilization but even earlier during meiotic maturation of human oocytes in culture. Since chromosomal analysis is simple in oocytes during meiotic maturation, the chromosomal status was analyzed in oocytes which remained unfertilized in a human in vitro

Horst Spielmann; Christiane Krüger; Manfred Stauber; Richard Vogel

1985-01-01

72

"Idiopathic" mental retardation and new chromosomal abnormalities  

PubMed Central

Mental retardation is a heterogeneous condition, affecting 1-3% of general population. In the last few years, several emerging clinical entities have been described, due to the advent of newest genetic techniques, such as array Comparative Genomic Hybridization. The detection of cryptic microdeletion/microduplication abnormalities has allowed genotype-phenotype correlations, delineating recognizable syndromic conditions that are herein reviewed. With the aim to provide to Paediatricians a combined clinical and genetic approach to the child with cognitive impairment, a practical diagnostic algorithm is also illustrated. The use of microarray platforms has further reduced the percentage of "idiopathic" forms of mental retardation, previously accounted for about half of total cases. We discussed the putative pathways at the basis of remaining "pure idiopathic" forms of mental retardation, highlighting possible environmental and epigenetic mechanisms as causes of altered cognition.

2010-01-01

73

Molecular cytogenetic mapping of Humulus lupulus sex chromosomes.  

PubMed

Dioecy is relatively rare in plants and sex determination systems vary among such species. A good example of a plant with heteromorphic sex chromosomes is hop (Humulus lupulus). The genotypes carrying XX or XY chromosomes correspond to female and male plants, respectively. Until now no clear cytogenetic markers for the sex chromosomes of hop have been established. Here, for the first time the sex chromosomes of hop are clearly identified and characterized. The high copy sequence of hop (HSR1) has been cloned and localized on chromosomes by fluorescence in situ hybridization. The HSR1 repeat has shown subtelomeric location on autosomes with the same intensity of the signal. The signal has been present in the subtelomeric region of the long arm and in the near-centromeric region but absent in the telomeric region of the short arm of the X chromosome. At the same time the signal has been found in the telomeric region only of the long arm of the Y chromosome. This finding indicates that the sex chromosomes of hop have evolved from a pair of autosomes via ancient translocation or inversion. The observation of the meiotic configuration of the sex bivalents shows the location of a pseudoautosomal region on the long arms of X and Y chromosomes. PMID:21709414

Divashuk, M G; Alexandrov, O S; Kroupin, P Yu; Karlov, G I

2011-01-01

74

Preimplantation genetic diagnosis of numerical and structural chromosome abnormalities  

Microsoft Academic Search

The causes of the decline in implantation rates observed with increasing maternal age are still a matter for debate. Data from oocyte donation strongly suggest that in women of advanced reproductive age, the ability to become pregnant is largely unaffected while oocyte quality is compromised. The incidence of chromosomal abnormalities in embryos is considerably higher than that reported in spontaneous

Santiago Munné

2002-01-01

75

Relationship of Gene Expression and Chromosomal Abnormalities in Colorectal Cancer  

Microsoft Academic Search

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

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

76

Advanced age increases chromosome structural abnormalities in human spermatozoa  

PubMed Central

This study explores the relationship between sperm structural aberrations and age by using a multicolor multichromosome FISH strategy that provides information on the incidence of duplications and deletions on all the autosomes. ToTelvysion kit (Abbott Molecular, Abbott Park, IL, USA) with telomere-specific probes was used. We investigated the sperm of 10 male donors aged from 23 to 74 years old. The donors were divided into two groups according to age, a cohort of five individuals younger than 40 and a cohort of five individuals older than 60 years. The goal of this study was to determine (1) the relationship between donor age and frequency and type of chromosome structural abnormalities and (2) chromosomes more frequently involved in sperm structural aberrations. We found that the older patients had a higher rate of structural abnormalities (6.6%) compared with the younger cohort (4.9%). Although both duplications and deletions were seen more frequently in older men, our findings demonstrate the presence of an excess of duplications versus deletions in both groups at a ratio of 2 to 1. We demonstrate that the distribution of duplications and deletions was not linear along the chromosomes, although a trend toward a higher rate of abnormalities in larger chromosomes was observed. This work is the first study addressing the frequencies of sperm chromosome structural aberrations of all autosomes in a single assay thus making a contribution to the clarification of the amount and origin of damage present in human spermatozoa and in relation to age.

Templado, Cristina; Donate, Anna; Giraldo, Jesus; Bosch, Merce; Estop, Anna

2011-01-01

77

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.

78

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

PubMed

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 São 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 São 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

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

79

Sex chromosome evolution in the clam shrimp, Eulimnadia texana.  

PubMed

Chromosomes that determine sex are predicted to evolve differently than autosomes: a lack of recombination on one of the two sex chromosomes is predicted to allow an accumulation of deleterious alleles that eventually leads to reduced functionality and potential physical degradation of the nonrecombining chromosome. Because these changes should occur at an elevated evolutionary rate, it is difficult to find appropriate species in which to test these evolutionary predictions. The unique genetic sex-determining mechanism of the crustacean Eulimnadia texana prevents major chromosome degeneration because of expression of both 'proto-sex' (i.e. early stage of development) chromosomes in homozygous form (ZZ and WW). Herein, we exploit this unique genetic system to examine the predicted accumulation of deleterious alleles by comparing both homogametic sexual types to their heterogametic counterpart. We report differences in crossing over in a sex-linked region in the ZW hermaphrodites (approximately 3%) relative to the ZZ males (approximately 21%), indicative of cross-over suppression in the ZW hermaphrodites. Additionally, we report that both ZZ and WW genotypes have reduced fitness relative to ZW hermaphrodites, which is consistent with the prediction of harboured recessive mutations embedded on both the Z and the W chromosomes. These results suggest that the proto-sex chromosomes in E. texana accumulate recessive deleterious alleles. We hypothesize that recessive deleterious alleles of large effect cannot accumulate because of expression in both ZZ and WW individuals, keeping both chromosomes from losing significant function. PMID:20298443

Weeks, S C; Benvenuto, C; Sanderson, T F; Duff, R J

2010-05-01

80

Chromosome abnormalities and their relationship to morphology and development of human embryos  

Microsoft Academic Search

This review covers the relationship between chromosome abnormalities, morphological abnormalities and embryonic development. The baseline of chromosome abnormalities in human embryos produced by assisted reproduction is higher than 50%, regardless of maternal age. While aneuploidy increases with maternal age, abnormalities arising post-meiotically, such as mosaicism, chaoticism, polyploidy and haploidy, have similar incidence in all age groups (about 33%). Post-meiotic abnormalities

Santiago Munné

2006-01-01

81

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

PubMed Central

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.

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

82

A neo-sex chromosome that drives postzygotic sex determination in the hessian fly (Mayetiola destructor).  

PubMed

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

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

2010-03-01

83

Effects of sex chromosome aneuploidy on male sexual behavior.  

PubMed

Incidence of sex chromosome aneuploidy in men is as high as 1:500. The predominant conditions are an additional Y chromosome (47,XYY) or an additional X chromosome (47,XXY). Behavioral studies using animal models of these conditions are rare. To assess the role of sex chromosome aneuploidy on sexual behavior, we used mice with a spontaneous mutation on the Y chromosome in which the testis-determining gene Sry is deleted (referred to as Y(-)) and insertion of a Sry transgene on an autosome. Dams were aneuploid (XXY(-)) and the sires had an inserted Sry transgene (XYSry). Litters contained six male genotypes, XY, XYY(-), XXSry, XXY(-)Sry, XYSry and XYY(-)Sry. In order to eliminate possible differences in levels of testosterone, all of the subjects were castrated and received testosterone implants prior to tests for male sex behavior. Mice with an additional copy of the Y(-) chromosome (XYY(-)) had shorter latencies to intromit and achieve ejaculations than XY males. In a comparison of the four genotypes bearing the Sry transgene, males with two copies of the X chromosome (XXSry and XXY(-)Sry) had longer latencies to mount and thrust than males with only one copy of the X chromosome (XYSry and XYY(-)Sry) and decreased frequencies of mounts and intromissions as compared with XYSry males. The results implicate novel roles for sex chromosome genes in sexual behaviors. PMID:18363850

Park, J H; Burns-Cusato, M; Dominguez-Salazar, E; Riggan, A; Shetty, S; Arnold, A P; Rissman, E F

2008-08-01

84

Sex-Specific Embryonic Gene Expression in Species with Newly Evolved Sex Chromosomes  

PubMed Central

Sex chromosome dosage differences between females and males are a significant form of natural genetic variation in many species. Like many species with chromosomal sex determination, Drosophila females have two X chromosomes, while males have one X and one Y. Fusions of sex chromosomes with autosomes have occurred along the lineage leading to D. pseudoobscura and D. miranda. The resulting neo-sex chromosomes are gradually evolving the properties of sex chromosomes, and neo-X chromosomes are becoming targets for the molecular mechanisms that compensate for differences in X chromosome dose between sexes. We have previously shown that D. melanogaster possess at least two dosage compensation mechanisms: the well- characterized MSL-mediated dosage compensation active in most somatic tissues, and another system active during early embryogenesis prior to the onset of MSL-mediated dosage compensation. To better understand the developmental constraints on sex chromosome gene expression and evolution, we sequenced mRNA from individual male and female embryos of D. pseudoobscura and D. miranda, from ?0.5 to 8 hours of development. Autosomal expression levels are highly conserved between these species. But, unlike D. melanogaster, we observe a general lack of dosage compensation in D. pseudoobscura and D. miranda prior to the onset of MSL-mediated dosage compensation. Thus, either there has been a lineage-specific gain or loss in early dosage compensation mechanism(s) or increasing X chromosome dose may strain dosage compensation systems and make them less effective. The extent of female bias on the X chromosomes decreases through developmental time with the establishment of MSL-mediated dosage compensation, but may do so more slowly in D. miranda than D. pseudoobscura. These results also prompt a number of questions about whether species with more sex-linked genes have more sex-specific phenotypes, and how much transcript level variance is tolerable during critical stages of development.

Lott, Susan E.; Villalta, Jacqueline E.; Zhou, Qi; Bachtrog, Doris; Eisen, Michael B.

2014-01-01

85

Evolution of Genomic Structures on Mammalian Sex Chromosomes  

PubMed Central

Throughout mammalian evolution, recombination between the two sex chromosomes was suppressed in a stepwise manner. It is thought that the suppression of recombination led to an accumulation of deleterious mutations and frequent genomic rearrangements on the Y chromosome. In this article, we review three evolutionary aspects related to genomic rearrangements and structures, such as inverted repeats (IRs) and palindromes (PDs), on the mammalian sex chromosomes. First, we describe the stepwise manner in which recombination between the X and Y chromosomes was suppressed in placental mammals and discuss a genomic rearrangement that might have led to the formation of present pseudoautosomal boundaries (PAB). Second, we describe ectopic gene conversion between the X and Y chromosomes, and propose possible molecular causes. Third, we focus on the evolutionary mode and timing of PD formation on the X and Y chromosomes. The sequence of the chimpanzee Y chromosome was recently published by two groups. Both groups suggest that rapid evolution of genomic structure occurred on the Y chromosome. Our re-analysis of the sequences confirmed the species-specific mode of human and chimpanzee Y chromosomal evolution. Finally, we present a general outlook regarding the rapid evolution of mammalian sex chromosomes.

Katsura, Yukako; Iwase, Mineyo; Satta, Yoko

2012-01-01

86

Dosage compensation, the origin and the afterlife of sex chromosomes  

Microsoft Academic Search

Over the past 100 years Drosophila has been developed into an outstanding model system for the study of evolutionary processes. A fascinating aspect of evolution\\u000a is the differentiation of sex chromosomes. Organisms with highly differentiated sex chromosomes, such as the mammalian X and\\u000a Y, must compensate for the imbalance in gene dosage that this creates. The need to adjust the

Jan Larsson; Victoria H. Meller

2006-01-01

87

Fetal Facial Defects: Associated Malformations and Chromosomal Abnormalities  

Microsoft Academic Search

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

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

1993-01-01

88

Extreme heterochiasmy and nascent sex chromosomes in European tree frogs  

PubMed Central

We investigated sex-specific recombination rates in Hyla arborea, a species with nascent sex chromosomes and male heterogamety. Twenty microsatellites were clustered into six linkage groups, all showing suppressed or very low recombination in males. Seven markers were sex linked, none of them showing any sign of recombination in males (r=0.00 versus 0.43 on average in females). This opposes classical models of sex chromosome evolution, which envision an initially small differential segment that progressively expands as structural changes accumulate on the Y chromosome. For autosomes, maps were more than 14 times longer in females than in males, which seems the highest ratio documented so far in vertebrates. These results support the pleiotropic model of Haldane and Huxley, according to which recombination is reduced in the heterogametic sex by general modifiers that affect recombination on the whole genome.

Berset-Brandli, Laura; Jaquiery, Julie; Broquet, Thomas; Ulrich, Yuko; Perrin, Nicolas

2008-01-01

89

Wide range of chromosome abnormalities in the embryos of young egg donors  

Microsoft Academic Search

Embryo chromosome studies show high rates of abnormalities, above 50%, but most embryos studied were from patients aged 35 and older. The objectives of this study were firstly, to evaluate the rate of chromosome abnormalities in embryos from young egg donors, and secondly, to compare the range of chromosome abnormality rates between donors and non-egg donor cycles, both undergoing preimplantation

S Munní; J Ary; C Zouves; T Escudero; F Barnes; C Cinioglu; B Ary; J Cohen

2006-01-01

90

Identification of embryonic chromosomal abnormality using FISH-based preimplantaion genetic diagnosis  

Microsoft Academic Search

Objective: Embryonic chromosomal abnormality is one of the main reasons for in vitro fertilization (IVF) failure. This study aimed at evaluating the value of Fluorescence in-situ Hybridization (FISH)-based Preimplantation Ge- netic Diagnosis (PGD) in screening for embryonic chromosomal abnormality to increase the successful rate of IVF. Method: Ten couples, four with high risk of chromosomal abnormality and six infertile couples,

YE Ying-hui; XU Chen-ming; QIAN Yu-li

91

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

Microsoft Academic Search

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

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

2001-01-01

92

Is there a relationship between sperm chromosome abnormalities and sperm morphology?  

Microsoft Academic Search

This review explores the relationship between sperm chromosomal constitution and morphology. With the advent of techniques for obtaining information on the chromosome complements of spermatozoa, this relationship has been studied in fertile men and in men with a high frequency of chromosomal abnormalities. Using human sperm karyotype analysis, no relationship between sperm chromosome abnormalities and morphology was found in fertile

Fei Sun; Evelyn Ko; Renée H Martin

2006-01-01

93

Evolution of multiple sex chromosomes in the spider genus Malthonica (Araneae: Agelenidae) indicates unique structure of the spider sex chromosome systems.  

PubMed

Most spiders exhibit a multiple sex chromosome system, X(1)X(2)0, whose origin has not been satisfactorily explained. Examination of the sex chromosome systems in the spider genus Malthonica (Agelenidae) revealed considerable diversity in sex chromosome constitution within this group. Besides modes X(1)X(2)0 (M. silvestris) and X(1)X(2)X(3)0 (M. campestris), a neo-X(1)X(2)X(3)X(4)X(5)Y system in M. ferruginea was found. Ultrastructural analysis of spread pachytene spermatocytes revealed that the X(1)X(2)0 and X(1)X(2)X(3)0 systems include a pair of homomorphic sex chromosomes. Multiple X chromosomes and the pair exhibit an end-to-end pairing, being connected by attachment plaques. The X(1)X(2)X(3)X(4)X(5)Y system of M. ferruginea arose by rearrangement between the homomorphic sex chromosome pair and an autosome. Multiple X chromosomes and the sex chromosome pair do not differ from autosomes in a pattern of constitutive heterochromatin. Ultrastructural data on sex chromosome pairing in other spiders indicate that the homomorphic sex chromosome pair forms an integral part of the spider sex chromosome systems. It is suggested that this pair represents ancestral sex chromosomes of spiders, which generated multiple X chromosomes by non-disjunctions. Structural differentiation of newly formed X chromosomes has been facilitated by heterochromatinization of sex chromosome bivalents observed in prophase I of spider females. PMID:17899407

Král, Jirí

2007-01-01

94

The pseudoautosomal regions of the human sex chromosomes  

Microsoft Academic Search

In human females, both X chromosomes are equivalent in size and genetic content, and pairing and recombination can theoretically occur anywhere along their entire length. In human males, however, only small regions of sequence identity exist between the sex chromosomes. Recombination and genetic exchange is restricted to these regions of identity, which cover 2.6 and 0.4 Mbp, respectively, and are

Gudrun A. Rappold

1993-01-01

95

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

PubMed Central

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.

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

2014-01-01

96

Heritable artificial sex chromosomes in the medaka, Oryzias latipes  

Microsoft Academic Search

Chromosomal sex determination is widely used by vertebrates, however, only two genes have been identified as master sex-determining genes: SRY\\/Sry in mammals and DMY in the teleost medaka. Transfer of both genes into genetically female (XX) individuals can induce male development. However, transgenic strains have not been established in both cases because of infertility of the transgenic founders in mammals

H Otake; H Masuyama; Y Mashima; A Shinomiya; T Myosho; Y Nagahama; M Matsuda; S Hamaguchi; M Sakaizumi

2010-01-01

97

CYTOGENETIC ABNORMALITY IN MAN--Wider Implications of Theories of Sex Chromatin Origin  

PubMed Central

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.

Miles, Charles P.

1962-01-01

98

Sex determination in mice: Y and chromosome 17 interactions.  

PubMed

Mice provide material for studies of Y-chromosomal and autosomal sequences involved in sex determination. Eicher and coworkers have identified four subregions in the mouse Y chromosome, one of which corresponds to the Sxr fragment. This fragment demonstrates that only a small portion of the Y is necessary for male sex determination. The mouse Y chromosome also shows variants: the BALB/cWt Y chromosome, which causes nondisjunction of the Y in some germ cells leading to XO and XYY cells and resulting in many infertile true hermaphrodites; the YDom, a wild-type chromosome which can result in sex reversal on a C57BL/6J background; and Y-chromosomal variants detected with Y-derived genomic DNA clones among inbred strains. Two different autosomal loci affecting sex differentiation have been identified in the mouse by Eicher and coworkers. The first of these has not been mapped to a particular chromosome and has been designated Tda-1 (Testis-determining autosomal-1). This is the locus in C57BL/6J mice at which animals must be homozygous in order to develop as true hermaphrodites or sex-reversed animals in the presence of YDom. The other locus has been identified on proximal chromosome 17. This locus also caused hermaphrodites on the C57BL/6J background and it is most easily interpreted as a locus deleted in Thp. It is located in a region on chromosome 17 containing other genes or DNA sequences that may be related to sex determination. These include both the Hye (histocompatibility Y expression) locus that affects the amount of male-specific antigen detected by serological and cell-mediated assays and a concentration of Bkm sequences.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3503719

Erickson, R P; Durbin, E J; Tres, L L

1987-01-01

99

Sex chromosome differentiation in Belostoma (Insecta: Heteroptera: Belostomatidae).  

PubMed

Belostoma, a genus of the family Belostomatidae, includes species of great ecological importance as biocontrol agents. Few species of these species have been the subject of cytogenetic analyses. Karyotypic evolution in this genus involves agmatoploidy and simploidy; there are also different sex chromosome systems. We examined two Belostoma species (B. dilatatum and B. candidulum) collected from the Paranapanema River Basin (Brazil). Mitotic and meiotic analysis revealed 2n(?) = 26 + X?X?X?Y for B. dilatatum and 2n(?) = 14 + XY for B. candidulum; both karyotypes have holokinetic chromosomes. Differences in heterochromatin distribution were also observed between the species, besides variation in the localization of CMA??/DAPI? blocks. The existence of different types of sex chromosome systems in these species was confirmed based on arrangements of the chromosomes in different meiotic stages. We identified a new sex system in B. dilatatum, and make the first cytogenetic report on B. candidulum. PMID:22653651

Bardella, V B; Dias, A L; Giuliano-Caetano, L; Ribeiro, J R I; da Rosa, R

2012-01-01

100

Mouse models for evaluating sex chromosome effects that cause sex differences in non-gonadal tissues  

PubMed Central

XX and XY cells have a different number of X and Y genes. These differences in their genomes cause sex differences in the functions of cells, both in the gonads and in non-gonadal tissues. This review discusses mouse models that have shed light on these direct genetic effects of sex chromosomes that cause sex differences in physiology. Because many sex differences in tissues are caused by different effects of male and female gonadal hormones, it is important to attempt to discriminate between direct genetic and hormonal effects. Numerous mouse models exist in which the number of X or Y genes is manipulated, to observe the effects on phenotype. In two models, the Afour core genotypes@ model and SF1 knockout gonadless mice, it has been possible to detect sex chromosome effects that are not explained by group differences in gonadal hormones. Moreover, mouse models are available to determine whether the sex chromosome effects are caused by X or Y genes.

Arnold, Arthur P.

2009-01-01

101

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

PubMed

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

Lalatta, Faustina; Tint, G Stephen

2013-11-01

102

Replacing the combined test by cell-free DNA testing in screening for trisomies 21, 18 and 13: impact on the diagnosis of other chromosomal abnormalities.  

PubMed

Objective: To estimate the proportion of other chromosomal abnormalities that could be missed if combined testing was replaced by cell-free (cf) DNA testing as the method of screening for trisomies 21, 18 and 13. Methods: The prevalence of trisomies 21, 18 or 13, sex chromosome aneuploidies, triploidy and other chromosomal abnormalities was examined in pregnancies undergoing first-trimester combined screening and chorionic villus sampling (CVS). Results: In 1,831 clinically significant chromosomal abnormalities in pregnancies with combined risk for trisomies 21, 18 and 13 ?1:100, the contribution of trisomies 21, 18 or 13, sex chromosome aneuploidies, triploidy and other chromosomal abnormalities at high risk of adverse outcome was 82.9, 8.2, 3.9 and 5.0%, respectively. Combined screening followed by CVS for risk ?1:10 and cfDNA testing for risk 1:11-1:2,500 could detect 97% of trisomy 21 and 98% of trisomies 18 and 13. Additionally, 86% of monosomy X, half of 47,XXY, 47,XYY or 47,XXX, half of other chromosomal abnormalities and one third of triploidies, which are currently detected by combined screening and CVS for risk ?1:100, could be detected. Conclusions: Screening by cfDNA testing, contingent on results of combined testing, improves detection of trisomies, but misses a few of the other chromosomal abnormalities detected by screening with the combined test. © 2014 S. Karger AG, Basel. PMID:24525399

Syngelaki, Argyro; Pergament, Eugene; Homfray, Tessa; Akolekar, Ranjit; Nicolaides, Kypros H

2014-01-01

103

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  

Microsoft Academic Search

Chromosomal sex determination is the prevalent system found in animals but is rare among turtles. In fact, heteromorphic sex\\u000a chromosomes are known in only seven of the turtles possessing genotypic sex determination (GSD), two of which correspond to\\u000a cryptic sex microchromosomes detectable only with high-resolution cytogenetic techniques. Sex chromosomes were undetected\\u000a in previous studies of Emydura macquarii, a GSD side-necked

Pedro Alonzo Martinez; Tariq Ezaz; Nicole Valenzuela; Arthur Georges; Jennifer A. Marshall Graves

2008-01-01

104

Spermatogenic failure in male mice with four sex chromosomes.  

PubMed

There is accumulating evidence that meiosis, like mitosis, is monitored by a number of checkpoints. In mammals, the presence of asynapsed chromosomes at pachytene triggers a checkpoint (the pachytene or synapsis checkpoint) that removes cells via a p53-independent apoptotic pathway. In the special case of the sex bivalent in males, it is pseudoautosomal region (PAR) asynapsis that triggers the checkpoint. In male mice with three sex chromosomes (XYY or XYY(*X)) some pachytene spermatocytes achieve full (trivalent) PAR synapsis, but in many cells one sex chromosome remains as a univalent, thus triggering the checkpoint. Sperm counts in these males have been shown to be positively correlated with trivalent frequencies. In the present study sperm production and levels of sex chromosome synapsis were studied in mice with four sex chromosomes (XYYY(*X)) and XYY(*X)Y(*X)). These mice proved to be more severely affected than XYY or XYY(*X) mice. Nevertheless, pachytene synaptonemal complex analysis revealed that full PAR synapsis was achieved through the formation of radial quadrivalents or through the formation of two sex bivalents in 21%-49% of cells analysed. Given these levels of full PAR synapsis, the sperm counts were consistently lower than would have been predicted from the relationship between levels of PAR synapsis and sperm counts in mice with three sex chromosomes. It has been suggested that the inactivation of the asynapsed non-PAR X and Y axes of the XY bivalent of normal males (MSCI), which occurs during meiotic prophase, may be driven by Xist transcripts originating from the X. If this is the case, the non-PAR Y axes of YY and YY(*X) bivalents would fail to undergo MSCI. This could be cell lethal, either because of 'inappropriate' Y gene expression, or because the non-PAR Y axis may now trigger the synapsis checkpoint. PMID:11453555

Rodriguez, T A; Burgoyne, P S

2001-05-01

105

Control of introduced species using Trojan sex chromosomes.  

PubMed

To control introduced exotic species that have predominantly genetic, but environmentally reversible, sex determination (e.g. many species of fish), Gutierrez and Teem recently modeled the use of carriers of Trojan Y chromosomes--individuals who are phenotypically sex reversed from their genotype. Repeated introduction of YY females into wild populations should produce extreme male-biased sex ratios and eventual elimination of XX females, thus leading to population extinction. Analogous dynamics are expected in systems in which sex determination is influenced by one or a few major genes on autosomes. PMID:17640769

Cotton, Samuel; Wedekind, Claus

2007-09-01

106

Sex-specific adaptation drives early sex chromosome evolution in Drosophila  

PubMed Central

Most species’ sex chromosomes are derived from ancient autosomes and show few signatures of their origins. We studied the sex chromosomes of Drosophila miranda, where a neo-Y chromosome originated only about 1 million years (MY) ago. Whole genome and transcriptome analysis reveals massive degeneration of the neo-Y, that male-beneficial genes on the neo-Y are more likely to undergo accelerated protein-evolution, and that neo-Y genes evolve biased expression towards male-specific tissues, i.e. the shrinking gene content of the neo-Y becomes masculinized. In contrast, while older X chromosomes show a paucity of genes expressed in male tissues, neo-X genes highly expressed in male-specific tissues undergo increased rates of protein evolution if haploid in males. Thus, the response to sex-specific selection can shift at different stages of X differentiation, resulting in masculinization or demasculinization of the X-chromosomal gene content.

Zhou, Qi; Bachtrog, Doris

2014-01-01

107

Neurogenin 3 mediates sex chromosome effects on the generation of sex differences in hypothalamic neuronal development  

PubMed Central

The organizational action of testosterone during critical periods of development is the cause of numerous sex differences in the brain. However, sex differences in neuritogenesis have been detected in primary neuronal hypothalamic cultures prepared before the peak of testosterone production by fetal testis. In the present study we assessed the hypothesis of that cell-autonomous action of sex chromosomes can differentially regulate the expression of the neuritogenic gene neurogenin 3 (Ngn3) in male and female hypothalamic neurons, generating sex differences in neuronal development. Neuronal cultures were prepared from male and female E14 mouse hypothalami, before the fetal peak of testosterone. Female neurons showed enhanced neuritogenesis and higher expression of Ngn3 than male neurons. The silencing of Ngn3 abolished sex differences in neuritogenesis, decreasing the differentiation of female neurons. The sex difference in Ngn3 expression was determined by sex chromosomes, as demonstrated using the four core genotypes mouse model, in which a spontaneous deletion of the testis-determining gene Sry from the Y chromosome was combined with the insertion of the Sry gene onto an autosome. In addition, the expression of Ngn3, which is also known to mediate the neuritogenic actions of estradiol, was increased in the cultures treated with the hormone, but only in those from male embryos. Furthermore, the hormone reversed the sex differences in neuritogenesis promoting the differentiation of male neurons. These findings indicate that Ngn3 mediates both cell-autonomous actions of sex chromosomes and hormonal effects on neuritogenesis.

Scerbo, Maria J.; Freire-Regatillo, Alejandra; Cisternas, Carla D.; Brunotto, Mabel; Arevalo, Maria A.; Garcia-Segura, Luis M.; Cambiasso, Maria J.

2014-01-01

108

Genetic mapping of sex determination in a wild strawberry, Fragaria virginiana, reveals earliest form of sex chromosome  

Microsoft Academic Search

The evolution of separate sexes (dioecy) from hermaphroditism is one of the major evolutionary transitions in plants, and this transition can be accompanied by the development of sex chromosomes. Studies in species with intermediate sexual systems are providing unprecedented insight into the initial stages of sex chromosome evolution. Here, we describe the genetic mechanism of sex determination in the octoploid,

R B Spigler; K S Lewers; D S Main; T-L Ashman

2008-01-01

109

Incomplete dosage compensation in an evolving Drosophila sex chromosome.  

PubMed Central

Cellular autoradiography was used to measure relative rates of chromosomal RNA synthesis and to examine the regulatory phenomenon of X-linked dosage compensation in Drosophila miranda, a species containing two distinct, nonhomologous X chromosomes (X1 and X2). The X1 chromosome was found to be dosage-compensated, since the rate of RNA synthesis along the single X1 chromosome in males equaled that of both X1 chromosomes in females. Unlike other sex chromosomes that have been studied, the more recently evolved X2 heterochromosome exhibited regional differences in transcriptional activity when males and females were compared. The distal 10% of the X2 was not dosage-compensated, whereas the majority of an interior segment, representing 30% of the X2 chromosome's length, was found to be dosage-compensated. Our data are consistent with the idea that the evolution of X2 dosage compensation has paralleled the differentiation of the X2 sex chromosome. In addition, gene rearrangement seems to have accompanied the acquisition of a dosage-compensory mechanism in the X2.

Strobel, E; Pelling, C; Arnheim, N

1978-01-01

110

Genome structure and primitive sex chromosome revealed in Populus  

SciTech Connect

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.

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

2008-01-01

111

Analysis of Sex Chromosomes in Preimplantation Genetic Diagnosis for X-Chromosome-Linked Disorders  

Microsoft Academic Search

Preimplantation genetic diagnosis (PGD) is diagnostic tool to avoid inheritance of genetic disease by transferring unaffected embryos. Recently, PCR and FISH have been mainly applied to the diagnosis of single gene disorders and chromosomal abnormalities, respectively. Since with PGD, only a few cells are available for genetic tests, both gene and chromosomes analysis have to be obtained from the same,

Harumi Kubo; Yutaka Sasabe; Takayo Nishimura

2002-01-01

112

Chromosome abnormalities in sperm from infertile men with normal somatic karyotypes: teratozoospermia.  

PubMed

Teratozoospermia is characterized by the presence of spermatozoa with abnormal morphology in sperm. This condition is frequently associated with infertility and intracytoplasmic sperm injection (ICSI) is frequently used as the treatment of choice. However, the use of ICSI has created consequential debate concerning the genetic risk for the offspring. Fluorescence in situ hybridization technique (FISH), allowing the specific identification of human chromosomes in sperm nuclei, has been used to study chromosome abnormalities in sperm from men with teratozoospermia and a normal karyotype. In this review, we present studies that have tried to determine if men with a normal blood karyotype but suffering from teratozoospermia present a higher aneuploidy frequency. The literature is limited to three forms of teratozoospermia. The first group consists of "polymorphic teratozoospermia", where a majority of spermatozoa display more than one type of abnormality. In this case, only a slight increase in aneuploidy frequency is observed, which cannot be differentiated from the results observed in oligo-astheno-teratozoospermia (OAT). The second group, named "globozoospermia", is characterized by round spermatic heads, absence of acrosome and disorganization of mid-piece and tail. In this case, some studies have shown a significant, but moderate, increase in the aneuploidy frequency for acrocentrics and sex chromosomes. The aneuploidy frequency remains low, also ICSI can be proposed to these patients, but few successes occur. The third group consists of "enlarged head teratozoospermia", where almost all spermatozoa have an enlarged head, multiple tail and abnormal acrosome. In this case a very high level of missegregation is observed, leading to nearly 100% aneuploidy. In this particular group, ICSI must be refuted, and patients have to be redirected to other possibilities, like sperm donation. PMID:16192715

Machev, N; Gosset, P; Viville, S

2005-01-01

113

Evidence for different origin of sex chromosomes in snakes, birds, and mammals and step-wise differentiation of snake sex chromosomes  

PubMed Central

All snake species exhibit genetic sex determination with the ZZ/ZW type of sex chromosomes. To investigate the origin and evolution of snake sex chromosomes, we constructed, by FISH, a cytogenetic map of the Japanese four-striped rat snake (Elaphe quadrivirgata) with 109 cDNA clones. Eleven of the 109 clones were localized to the Z chromosome. All human and chicken homologues of the snake Z-linked genes were located on autosomes, suggesting that the sex chromosomes of snakes, mammals, and birds were all derived from different autosomal pairs of the common ancestor. We mapped the 11 Z-linked genes of E. quadrivirgata to chromosomes of two other species, the Burmese python (Python molurus bivittatus) and the habu (Trimeresurus flavoviridis), to investigate the process of W chromosome differentiation. All and 3 of the 11 clones were localized to both the Z and W chromosomes in P. molurus and E. quadrivirgata, respectively, whereas no cDNA clones were mapped to the W chromosome in T. flavoviridis. Comparative mapping revealed that the sex chromosomes are only slightly differentiated in P. molurus, whereas they are fully differentiated in T. flavoviridis, and E. quadrivirgata is at a transitional stage of sex-chromosome differentiation. The differentiation of sex chromosomes was probably initiated from the distal region on the short arm of the protosex chromosome of the common ancestor, and then deletion and heterochromatization progressed on the sex-specific chromosome from the phylogenetically primitive boids to the more advanced viperids.

Matsubara, Kazumi; Tarui, Hiroshi; Toriba, Michihisa; Yamada, Kazuhiko; Nishida-Umehara, Chizuko; Agata, Kiyokazu; Matsuda, Yoichi

2006-01-01

114

Sequencing papaya X and Yh chromosomes reveals molecular basis of incipient sex chromosome evolution  

PubMed Central

Sex determination in papaya is controlled by a recently evolved XY chromosome pair, with two slightly different Y chromosomes controlling the development of males (Y) and hermaphrodites (Yh). To study the events of early sex chromosome evolution, we sequenced the hermaphrodite-specific region of the Yh chromosome (HSY) and its X counterpart, yielding an 8.1-megabase (Mb) HSY pseudomolecule, and a 3.5-Mb sequence for the corresponding X region. The HSY is larger than the X region, mostly due to retrotransposon insertions. The papaya HSY differs from the X region by two large-scale inversions, the first of which likely caused the recombination suppression between the X and Yh chromosomes, followed by numerous additional chromosomal rearrangements. Altogether, including the X and/or HSY regions, 124 transcription units were annotated, including 50 functional pairs present in both the X and HSY. Ten HSY genes had functional homologs elsewhere in the papaya autosomal regions, suggesting movement of genes onto the HSY, whereas the X region had none. Sequence divergence between 70 transcripts shared by the X and HSY revealed two evolutionary strata in the X chromosome, corresponding to the two inversions on the HSY, the older of which evolved about 7.0 million years ago. Gene content differences between the HSY and X are greatest in the older stratum, whereas the gene content and order of the collinear regions are identical. Our findings support theoretical models of early sex chromosome evolution.

Wang, Jianping; Na, Jong-Kuk; Yu, Qingyi; Gschwend, Andrea R.; Han, Jennifer; Zeng, Fanchang; Aryal, Rishi; VanBuren, Robert; Murray, Jan E.; Zhang, Wenli; Navajas-Perez, Rafael; Feltus, F. Alex; Lemke, Cornelia; Tong, Eric J.; Chen, Cuixia; Man Wai, Ching; Singh, Ratnesh; Wang, Ming-Li; Min, Xiang Jia; Alam, Maqsudul; Charlesworth, Deborah; Moore, Paul H.; Jiang, Jiming; Paterson, Andrew H.; Ming, Ray

2012-01-01

115

Identification of embryonic chromosomal abnormality using FISH-based preimplantaion genetic diagnosis  

Microsoft Academic Search

Objective: Embryonic chromosomal abnormality is one of the main reasons for in vitro fertilization (IVF) failure. This study\\u000a aimed at evaluating the value of Fluorescence in-situ Hybridization (FISH)-based Preimplantation Genetic Diagnosis (PGD) in\\u000a screening for embryonic chromosomal abnormality to increase the successful rate of IVF. Method: Ten couples, four with high\\u000a risk of chromosomal abnormality and six infertile couples, underwent

Ying-hui Ye; Chen-ming Xu; Fan Jin; Yu-li Qian

2004-01-01

116

Sex-biased chromatin and regulatory cross-talk between sex chromosomes, autosomes, and mitochondria  

PubMed Central

Several autoimmune and neurological diseases exhibit a sex bias, but discerning the causes and mechanisms of these biases has been challenging. Sex differences begin to manifest themselves in early embryonic development, and gonadal differentiation further bifurcates the male and female phenotypes. Even at this early stage, however, there is evidence that males and females respond to environmental stimuli differently, and the divergent phenotypic responses may have consequences later in life. The effect of prenatal nutrient restriction illustrates this point, as adult women exposed to prenatal restrictions exhibited increased risk factors of cardiovascular disease, while men exposed to the same condition did not. Recent research has examined the roles of sex-specific genes, hormones, chromosomes, and the interactions among them in mediating sex-biased phenotypes. Such research has identified testosterone, for example, as a possible protective agent against autoimmune disorders and an XX chromosome complement as a susceptibility factor in murine models of lupus and multiple sclerosis. Sex-biased chromatin is an additional and likely important component. Research suggesting a role for X and Y chromosome heterochromatin in regulating epigenetic states of autosomes has highlighted unorthodox mechanisms of gene regulation. The crosstalk between the Y chromosomes and autosomes may be further mediated by the mitochondria. The organelles have solely maternal transmission and exert differential effects on males and females. Altogether, research supports the notion that the interaction between sex-biased elements might exert novel regulatory functions in the genome and contribute to sex-specific susceptibilities to autoimmune and neurological diseases.

2014-01-01

117

Frequency and the type of chromosomal abnormalities in patients with primary amenorrhea in northeast of iran.  

PubMed

Objective(s): Primary and secondary amenorrhea are different from each other in that the former refers to a physiological failure in the onset of spontaneous menarche during the time when it is expected. whereas the latter involves the cessation of normal menstruation any time prior to menopause. In this study we aimed to investigate chromosomal abnormalities in patients with Primary Amenorrhea in Northeast of Iran by employing GTG banding. Materials and Methods: Chromosomal analysis was carried out on 180 cases that were referred from different clinics in eastern cities of Iran to our laboratory from 2004 to 2009. We implemented the suggested protocol regarding peripheral blood lymphocyte culture for metaphase chromosome preparation as well as conventional analysis for G-banded chromosome. Results: The karyotype results revealed that 75.55% (n=136) had normal chromosome composition and 24.45% (n=44) showed chromosomal abnormalities. Among the patients with abnormal chromosome constituents 86.36% exhibit numerical aberration and 13.63% showed structural abnormalities. The most frequent abnormality detected was X chromosome monosomy, homogeneous (21 cases -11.66%) or mosaic (8 cases - 4.44%). The other 6 cases (3.33%) had X chromosome structural imbalanced abnormalities (homogeneous or in mosaic). Discussion: As expected, this study confirmed previously reported cytogentic abnormalities in patients with amenorrhea. Although there are percentage differences between these studies and also verities in chromosomal abnormalities, they have still demonstrated the importance of cytogenetic investigations in the etiological diagnosis of amenorrhea. PMID:24250944

Mohajertehran, Farnaz; Ghodsi, Kazem; Hafizi, Leili; Rezaee, Ameneh

2013-04-01

118

Frequency and the type of chromosomal abnormalities in patients with primary amenorrhea in northeast of iran.  

PubMed

Objective(s): Primary and secondary amenorrhea are different from each other in that the former refers to a physiological failure in the onset of spontaneous menarche during the time when it is expected. whereas the latter involves the cessation of normal menstruation any time prior to menopause. In this study we aimed to investigate chromosomal abnormalities in patients with Primary Amenorrhea in Northeast of Iran by employing GTG banding. Materials and Methods: Chromosomal analysis was carried out on 180 cases that were referred from different clinics in eastern cities of Iran to our laboratory from 2004 to 2009. We implemented the suggested protocol regarding peripheral blood lymphocyte culture for metaphase chromosome preparation as well as conventional analysis for G-banded chromosome. Results: The karyotype results revealed that 75.55% (n=136) had normal chromosome composition and 24.45% (n=44) showed chromosomal abnormalities. Among the patients with abnormal chromosome constituents 86.36% exhibit numerical aberration and 13.63% showed structural abnormalities. The most frequent abnormality detected was X chromosome monosomy, homogeneous (21 cases -11.66%) or mosaic (8 cases - 4.44%). The other 6 cases (3.33%) had X chromosome structural imbalanced abnormalities (homogeneous or in mosaic). Discussion: As expected, this study confirmed previously reported cytogentic abnormalities in patients with amenorrhea. Although there are percentage differences between these studies and also verities in chromosomal abnormalities, they have still demonstrated the importance of cytogenetic investigations in the etiological diagnosis of amenorrhea. PMID:24250941

Mohajertehran, Farnaz; Ghodsi, Kazem; Hafizi, Leili; Rezaee, Ameneh

2013-04-01

119

Frequency and the Type of Chromosomal Abnormalities in Patients with Primary Amenorrhea in Northeast of Iran  

PubMed Central

Objective(s): Primary and secondary amenorrhea are different from each other in that the former refers to a physiological failure in the onset of spontaneous menarche during the time when it is expected. whereas the latter involves the cessation of normal menstruation any time prior to menopause. In this study we aimed to investigate chromosomal abnormalities in patients with Primary Amenorrhea in Northeast of Iran by employing GTG banding. Materials and Methods: Chromosomal analysis was carried out on 180 cases that were referred from different clinics in eastern cities of Iran to our laboratory from 2004 to 2009. We implemented the suggested protocol regarding peripheral blood lymphocyte culture for metaphase chromosome preparation as well as conventional analysis for G-banded chromosome. Results: The karyotype results revealed that 75.55% (n=136) had normal chromosome composition and 24.45% (n=44) showed chromosomal abnormalities. Among the patients with abnormal chromosome constituents 86.36% exhibit numerical aberration and 13.63% showed structural abnormalities. The most frequent abnormality detected was X chromosome monosomy, homogeneous (21 cases –11.66%) or mosaic (8 cases – 4.44%). The other 6 cases (3.33%) had X chromosome structural imbalanced abnormalities (homogeneous or in mosaic). Discussion: As expected, this study confirmed previously reported cytogentic abnormalities in patients with amenorrhea. Although there are percentage differences between these studies and also verities in chromosomal abnormalities, they have still demonstrated the importance of cytogenetic investigations in the etiological diagnosis of amenorrhea.

Mohajertehran, Farnaz; Ghodsi, Kazem; Hafizi, Leili; Rezaee, Ameneh

2013-01-01

120

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.  

PubMed

Chromosomal sex determination is the prevalent system found in animals but is rare among turtles. In fact, heteromorphic sex chromosomes are known in only seven of the turtles possessing genotypic sex determination (GSD), two of which correspond to cryptic sex microchromosomes detectable only with high-resolution cytogenetic techniques. Sex chromosomes were undetected in previous studies of Emydura macquarii, a GSD side-necked turtle. Using comparative genomic hybridization (CGH) and GTG-banding, a heteromorphic XX/XY sex chromosome system was detected in E. macquarii. The Y chromosome appears submetacentric and somewhat larger than the metacentric X, the first such report for turtles. CGH revealed a male-specific chromosomal region, which appeared heteromorphic using GTG-banding, and was restricted to the telomeric region of the p arm. Based on our observations and the current phylogeny of chelid turtles, we hypothesize that the sex chromosomes of E. macquarii might be the result of a translocation of an ancestral Y microchromosome as found in a turtle belonging to a sister clade, Chelodina longicollis, onto the tip of an autosome. However, in the absence of data from an outgroup, the opposite (fission of a large XY into an autosome and a micro-XY) is theoretically equally likely. Alternatively, the sex chromosome systems of E. macquarii and C. longicollis may have evolved independently. We discuss the potential causes and consequences of such putative chromosome rearrangements in the evolution of sex chromosomes and sex-determining systems of turtles in general. PMID:18679815

Martinez, Pedro Alonzo; Ezaz, Tariq; Valenzuela, Nicole; Georges, Arthur; Marshall Graves, Jennifer A

2008-01-01

121

Chromosome abnormalities and the genetics of congenital corneal opacification  

PubMed Central

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.

Mataftsi, A.; Islam, L.; Kelberman, D.; Sowden, J.C.

2011-01-01

122

Directly transmitted unbalanced chromosome abnormalities and euchromatic variants  

PubMed Central

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.

Barber, J

2005-01-01

123

Chromosome abnormalities clustering and its implications for pathogenesis and prognosis in myeloma  

Microsoft Academic Search

The nonrandom recurrent nature of chromosome abnormalities in myeloma suggests a role for them in disease pathogenesis. We performed a careful cytogenetic analysis of patients with abnormal karyotypes (n = 254), to discern patterns of association, search for novel abnormalities and elucidate clinical implications. Patients with karyotypic abnormalities suggestive of myelodysplasia\\/acute leukemia were excluded. In this study we compared survival

C S Debes-Marun; G W Dewald; S Bryant; E Picken; R Santana-Dávila; N González-Paz; J M Winkler; R A Kyle; M A Gertz; T E Witzig; A Dispenzieri; M Q Lacy; S V Rajkumar; J A Lust; P R Greipp; R Fonseca

2003-01-01

124

European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations (ECARUCA); an online database for rare chromosome abnormalities.  

PubMed

During recent years a considerable improvement in diagnostic techniques has enabled cytogeneticists to find more and smaller chromosomal aberrations. However, accurate clinical knowledge about rare chromosome disorders is frequently lacking, mostly due to a significant decline in publishable cases. On the other hand, there is an increasing demand from parents and physicians for reliable information. In order to improve the quality and the quantity of data available, we designed a new database named the European Cytogeneticists Association Register of Unbalanced Chromosome Aberrations (ECARUCA) at http://www.ecaruca.net. This Internet-database contains cytogenetic and clinical data of patients with rare chromosome abnormalities, including microscopically visible aberrations, as well as microdeletions and -duplications. Cases with certain breakpoints collected in the Zurich Cytogenetic Database were transferred to ECARUCA. The advantages of ECARUCA compared to existing sources are that ECARUCA is interactive, dynamic and has long-term possibilities to store cytogenetic, molecular and clinical data. Professionals can login to submit new cases and perform searches in the database through the Internet. Currently the database contains 1500 unique chromosomal aberrations from almost 4000 patients. A frequent submission of new data ensures the up-to-date quality of the collection. Individual parent accounts allow parents to inform the ECARUCA team about the follow-up of their child. The ECARUCA database provides health care workers with accurate information on clinical aspects of rare chromosome disorders. Additionally, detailed correlations between chromosome aberrations and their phenotypes are of invaluable help in localising genes for mental retardation and congenital anomalies. PMID:16829349

Feenstra, I; Fang, J; Koolen, D A; Siezen, A; Evans, C; Winter, R M; Lees, M M; Riegel, M; de Vries, B B A; Van Ravenswaaij, C M A; Schinzel, A

2006-01-01

125

Evolution of a recent neo-Y sex chromosome in a laboratory population of Drosophila  

Microsoft Academic Search

In many species of animals, one of the sexes has a chromosome that is structurally and functionally different from its socalled\\u000a homologue. Conventionally, it is called Y chromosome or W chromosome depending on whether it is present in males or females\\u000a respectively. The corresponding homologous chromosomes are called X and Z chromosomes. The dimorphic sex chromosomes are believed\\u000a to have

M. T. Tanuja; N. B. Ramachandra; H. A. Ranganath

1999-01-01

126

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

PubMed

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 the Y is absent in the germ line of those studied (Fredga et al., 1976). Therefore, (3) a mechanism of double nondisjunction in early fetal life of XY females has to be postulated, which replaces the Y in the germ line by duplication of the X. It is assumed (4) that the X of XY females bears a sex-reversal factor that affects the male determining action of the Y (Fredga et al., 1977). There is (5) a strong presumption that in most cases the XY females are those that produce daughters only, but (6) a few exceptions may occur (FRANK, unpublished observations), suggesting that the regulation according to assumption 3 (perhaps also to 4) is incomplete in XY females. In the present report, four females are described with a 31,XO karyotype, two females with 33,XYY or 32,XY/33,XYY, respectively, two males with a 33,XXY, and one male with a 32,XX/33,XXY karyotype, as observed in a consecutive series of 502 wood lemmings. The incidence of sex-chromosome anomalies in liveborn and adult animals was 2.3%; the overall incidence, including embryos, was 1.79%. Neither the somatic XO constitution nor the existence of an extra Y in females precludes fertility. However, the XXY condition in the male results in sterility. There is certain evidence that an instability of the proposed mechanism for double mitotic nondisjunction of the sex chromosomes in oogonia accounts for the high rate of sex-chromosome aberrations in wood lemmings, at least when the mother is XY. PMID:17494626

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

1976-01-01

127

Isolation and development of a molecular sex marker for Bassiana duperreyi, a lizard with XX/XY sex chromosomes and temperature-induced sex reversal.  

PubMed

Sex determination in the endemic Australian lizard Bassiana duperreyi (Scincidae) is influenced by sex chromosomes and incubation temperature, challenging the traditional dichotomy in reptilian sex determination. Analysis of those interactions requires sex chromosome markers to identify temperature-induced sex reversal. Here, we report the isolation of Y chromosome DNA sequence from B. duperreyi using amplified fragment length polymorphism PCR, the conversion of that sequence to a single-locus assay, and its combination with a single-copy nuclear gene (C-mos) to form a duplex PCR test for chromosomal sex. The accuracy of the assay was tested on an independent panel of individuals with known phenotypic sex. When used on offspring from field nests, our test identified the likely occurrence of a low rate of natural sex reversal in this species. This work represents the first report of Y chromosome sequence from a reptile and one of the few reptile sex tests. PMID:19277717

Quinn, Alexander E; Radder, Rajkumar S; Sarre, Stephen D; Georges, Arthur; Ezaz, Tariq; Shine, Richard

2009-06-01

128

Evaluation of routine prenatal ultrasound examination in detecting fetal chromosomal abnormalities in a low risk population  

Microsoft Academic Search

Prenatal diagnosis performed by fetal ultrasound scan is now a routine part of antenatal care in many countries. We have used our registry of congenital malformations to determine how many fetal anomalies and consequently how many chromosomal abnormalities are detected by this procedure. In our region, evaluation of prenatal diagnosis of chromosomal abnormalities in women of 38 years and younger

Claude Stoll; Béatrice Dott; Yves Alembik; Marie-Paule Roth

1993-01-01

129

Abnormal methylation pattern in constitutive and facultative (X inactive chromosome) heterochromatin of ICF patients.  

PubMed

We have investigated the distribution of DNA methylation in chromosomes and nuclei of normal individuals and ICF (Immunodeficiency, Centromeric instability and Facial abnormalities) syndrome patients, using 5-methylcytosine monoclonal antibody. In this syndrome, DNA digestion with methyl-sensitive enzymes has previously shown a specific hypomethylation of classical satellites located in constitutive heterochromatin. The chromosome methylation pattern confirms this hypomethylation showing in addition a clear undermethylation of facultative heterochromatin (X inactive chromosome). Antibodies give, in normal and ICF chromosomes, a non-uniform labeling of euchromatin, generating a weak R-like banding pattern on chromosomes. This pattern reflects an unequal distribution of DNA methylation over the genome disclosing another aspect of chromosome organization. The breakpoints of chromosome rearrangements and the heterochromatin stretchings observed in ICF patients were analyzed by means of in situ hybridization. These chromosome modifications involve hypomethylated classical DNA satellite sequences. The underlying hypomethylation, associated with an abnormal chromatin organization, may predispose to chromosome instability. PMID:7881405

Miniou, P; Jeanpierre, M; Blanquet, V; Sibella, V; Bonneau, D; Herbelin, C; Fischer, A; Niveleau, A; Viegas-Péquignot, E

1994-12-01

130

Gene organization of the liverwort Y chromosome reveals distinct sex chromosome evolution in a haploid system  

PubMed Central

Y chromosomes are different from other chromosomes because of a lack of recombination. Until now, complete sequence information of Y chromosomes has been available only for some primates, although considerable information is available for other organisms, e.g., several species of Drosophila. Here, we report the gene organization of the Y chromosome in the dioecious liverwort Marchantia polymorpha and provide a detailed view of a Y chromosome in a haploid organism. On the 10-Mb Y chromosome, 64 genes are identified, 14 of which are detected only in the male genome and are expressed in reproductive organs but not in vegetative thalli, suggesting their participation in male reproductive functions. Another 40 genes on the Y chromosome are expressed in thalli and male sexual organs. At least six of these genes have diverged X-linked counterparts that are in turn expressed in thalli and sexual organs in female plants, suggesting that these X- and Y-linked genes have essential cellular 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.

Yamato, Katsuyuki T.; Ishizaki, Kimitsune; Fujisawa, Masaki; Okada, Sachiko; Nakayama, Shigeki; Fujishita, Mariko; Bando, Hiroki; Yodoya, Kohei; Hayashi, Kiwako; Bando, Tomoyuki; Hasumi, Akiko; Nishio, Tomohisa; Sakata, Ryoko; Yamamoto, Masayuki; Yamaki, Arata; Kajikawa, Masataka; Yamano, Takashi; Nishide, Taku; Choi, Seung-Hyuk; Shimizu-Ueda, Yuu; Hanajiri, Tsutomu; Sakaida, Megumi; Kono, Kaoru; Takenaka, Mizuki; Yamaoka, Shohei; Kuriyama, Chiaki; Kohzu, Yoshito; Nishida, Hiroyuki; Brennicke, Axel; Shin-i, Tadasu; Kohara, Yuji; Kohchi, Takayuki; Fukuzawa, Hideya; Ohyama, Kanji

2007-01-01

131

Cytogenetics and mechanisms of spontaneous abortions: increased apoptosis and decreased cell proliferation in chromosomally abnormal villi  

Microsoft Academic Search

Genetic defects of the zygote, such as chromosome aberrations, are the most frequent causes of abnormal embryonic development and spontaneous abortion. However, the underlying mechanisms remain unknown. Chromosome aberrations likely cause changes in placental morphology and function (such as size, shape, vascularity, and the presence of trophoblastic inclusion). We postulated that chromosome aberrations may affect rates of cell proliferation or

M. B. Qumsiyeh; K.-R. Kim; M. N. Ahmed; W. Bradford

2000-01-01

132

Non-random abnormalities of chromosomes 3, 6, and 8 associated with posterior uveal melanoma.  

PubMed

We present ten cases of posterior uveal melanoma which were karyotyped after short-term culture. One tumour had a normal chromosome complement. The remaining nine tumours were cytogenetically abnormal, with chromosomes 3, 6, 8, 11, and 13 most frequently involved. Abnormalities of chromosome 13 were seen in two cases, chromosome 11 in three cases, and chromosomes 3, 6, and 8 in five cases. Four tumours, all derived from the ciliary body, demonstrated monosomy 3 and i(8q), confirming the involvement of these aberrations with a subgroup of uveal melanomas arising from the ciliary body. PMID:1384670

Sisley, K; Cottam, D W; Rennie, I G; Parsons, M A; Potter, A M; Potter, C W; Rees, R C

1992-10-01

133

Comparative Sex Chromosome Genomics in Snakes: Differentiation, Evolutionary Strata, and Lack of Global Dosage Compensation  

PubMed Central

Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females). Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae), but completely heteromorphic sex chromosomes in both garter snakes (Colubridae) and pygmy rattlesnake (Viperidae). Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases). This demonstrates that mutation rates are male-biased in snakes (male-driven evolution), but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex chromosomes evolution.

Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

2013-01-01

134

Comparative sex chromosome genomics in snakes: differentiation, evolutionary strata, and lack of global dosage compensation.  

PubMed

Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females). Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae), but completely heteromorphic sex chromosomes in both garter snakes (Colubridae) and pygmy rattlesnake (Viperidae). Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases). This demonstrates that mutation rates are male-biased in snakes (male-driven evolution), but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex chromosomes evolution. PMID:24015111

Vicoso, Beatriz; Emerson, J J; Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

2013-01-01

135

Clinical implications of chromosomal abnormalities in gastric adenocarcinomas  

SciTech Connect

Gastric carcinoma (GC) is one of the most common malignancies worldwide and has a very poor prognosis. Genetic imbalances in 62 primary gastric adenocarcinomas of various histopathologic types and pathologic stages and six gastric cancer-derived cell lines were analyzed by comparative genomic hybridization, and the relationship of genomic abnormalities to clinical features in primary GC was evaluated at a genome-wide level. Eighty-four percent of the tumors and all six cell lines showed DNA copy number changes. The recurrent chromosomal abnormalities including gains at 15 regions and losses at 8 regions were identified. Statistical analyses revealed that gains at 17q24-qter (53 percent), 20q13-qter (48 percent), 1p32-p36 (42 percent), 22q12-qter (27 percent), 17p13-pter (24 percent), 16p13-pter (21 percent), 6p21-pter (19 percent), 20p12-pter (19 percent), 7p21-pter (18 percent), 3q28-qter (8 percent), and 13q13-q14 (8 percent), and losses at 18q12-qter (11 percent), 3p12 (8 percent), 3p25-pter (8 percent), 5q14-q23 (8 percent), and 9p21-p23 (5 percent), are associated with unique patient or tumor-related features. GCs of differing histopathologic features were shown to be associated with distinct patterns of genetic alterations, supporting the notion that they evolve through distinct genetic pathways. Metastatic tumors were also associated with specific genetic changes. These regions may harbor candidate genes involved in the pathogenesis of this malignancy.

Wu, Chew-Wun; Chen, Gen-Der; Fann, Cathy S.-J.; Lee, Anna F.-Y.; Chi, Chin-Wen; Liu, Jacqueline M.; Weier, Ulli; Chen, Jeou-Yuan

2003-06-23

136

Construction of physical maps for the sex-specific regions of papaya sex chromosomes  

PubMed Central

Background Papaya is a major fruit crop in tropical and subtropical regions worldwide. It is trioecious with three sex forms: male, female, and hermaphrodite. Sex determination is controlled by a pair of nascent sex chromosomes with two slightly different Y chromosomes, Y for male and Yh for hermaphrodite. The sex chromosome genotypes are XY (male), XYh (hermaphrodite), and XX (female). The papaya hermaphrodite-specific Yh chromosome region (HSY) is pericentromeric and heterochromatic. Physical mapping of HSY and its X counterpart is essential for sequencing these regions and uncovering the early events of sex chromosome evolution and to identify the sex determination genes for crop improvement. Results A reiterate chromosome walking strategy was applied to construct the two physical maps with three bacterial artificial chromosome (BAC) libraries. The HSY physical map consists of 68 overlapped BACs on the minimum tiling path, and covers all four HSY-specific Knobs. One gap remained in the region of Knob 1, the only knob structure shared between HSY and X, due to the lack of HSY-specific sequences. This gap was filled on the physical map of the HSY corresponding region in the X chromosome. The X physical map consists of 44 BACs on the minimum tiling path with one gap remaining in the middle, due to the nature of highly repetitive sequences. This gap was filled on the HSY physical map. The borders of the non-recombining HSY were defined genetically by fine mapping using 1460?F2 individuals. The genetically defined HSY spanned approximately 8.5?Mb, whereas its X counterpart extended about 5.4?Mb including a 900 Kb region containing the Knob 1 shared by the HSY and X. The 8.5?Mb HSY corresponds to 4.5?Mb of its X counterpart, showing 4?Mb (89%) DNA sequence expansion. Conclusion The 89% increase of DNA sequence in HSY indicates rapid expansion of the Yh chromosome after genetic recombination was suppressed 2–3 million years ago. The genetically defined borders coincide with the common BACs on the minimum tiling paths of HSY and X. The minimum tiling paths of HSY and its X counterpart are being used for sequencing these X and Yh-specific regions.

2012-01-01

137

Chromosomal Abnormalities in Patients with Congenital Heart Disease  

PubMed Central

Background Chromosomal abnormalities (CAs) are an important cause of congenital heart disease (CHD). Objective Determine the frequency, types and clinical characteristics of CAs identified in a sample of prospective and consecutive patients with CHD. Method Our sample consisted of patients with CHD evaluated during their first hospitalization in a cardiac intensive care unit of a pediatric referral hospital in Southern Brazil. All patients underwent clinical and cytogenetic assessment through high-resolution karyotype. CHDs were classified according to Botto et al. Chi-square, Fisher exact test and odds ratio were used in the statistical analysis (p < 0.05). Results Our sample consisted of 298 patients, 53.4% males, with age ranging from 1 day to 14 years. CAs were observed in 50 patients (16.8%), and 49 of them were syndromic. As for the CAs, 44 (88%) were numeric (40 patients with +21, 2 with +18, 1 with triple X and one with 45,X) and 6 (12%) structural [2 patients with der(14,21), +21, 1 with i(21q), 1 with dup(17p), 1 with del(6p) and 1 with add(18p)]. The group of CHDs more often associated with CAs was atrioventricular septal defect. Conclusions CAs detected through karyotyping are frequent in patients with CHD. Thus, professionals, especially those working in Pediatric Cardiology Services, must be aware of the implications that performing the karyotype can bring to the diagnosis, treatment and prognosis and for genetic counseling of patients and families.

Trevisan, Patricia; Zen, Tatiana Diehl; Rosa, Rafael Fabiano Machado; da Silva, Juliane Nascimento; Koshiyama, Dayane Bohn; Paskulin, Giorgio Adriano; Zen, Paulo Ricardo Gazzola

2013-01-01

138

Molecular-cytogenetic analysis reveals sequence differences between the sex chromosomes of Oreochromis niloticus: evidence for an early stage of sex-chromosome differentiation  

Microsoft Academic Search

Sex determination in the Nile tilapia, Oreochromis niloticus, is primarily genetic, with XX females and XY males. A candidate sex-determining region in the terminal region of the largest chromosome pair has been identified by analysis of meiotic chromosomes. This region shows an inhibition of pairing and synapsis in the XY genotype, but not in XX or YY genotypes, suggesting that

S. C. Harvey; J. Masabanda; L. A. P. Carrasco; N. R. Bromage; D. J. Penman; D. K. Griffin

2002-01-01

139

Fifty probands with extra structurally abnormal chromosomes characterized by fluorescence in situ hybridization  

SciTech Connect

Extra structurally abnormal chromosomes (ESACs) are small supernumerary chromosomes often associated with developmental abnormalities and malformations. We present 50 probands with ESACs characterized by fluorescence in situ hybridization using centromere-specific probes and chromosome-specific libraries. ESAC-specific libraries were constructed by flow sorting and subsequent amplification by DOP-PCR. Using such ESAC-specific libraries we were able to outline the chromosome regions involved. Twenty-three of the 50 ESACs were inverted duplications of chromosome 15 (inv dup(15)), including patients with normal phenotypes and others with similar clinical symptoms. These 2 groups differed in size and shape of the inv dup(15). Patients with a large inv dup(15), which included the Prader-Willi region, had a high risk of abnormality, whereas patients with a small inv dup(15), not including the Prader-Willi region, were normal. ESACs derived from chromosomes 13 or 21 appeared to have a low risk of abnormality, while one out of 3 patients with an ESAC derived from chromosome 14 had discrete symptoms. One out of 3 patients with an ESAC derived from chromosome 22 had severe anomalies, corresponding to some of the manifestations of the cat eye syndrome. Small extra ring chromosomes of autosomal origin and ESACs identified as i(12p) or i(18p) were all associated with a high risk of abnormality. 42 refs., 2 figs., 2 tabs.

Blennow, E.; Telenius, H.; Nordenskjoeld, M. [Karolinska Hospital, Stockholm (Sweden)] [and others

1995-01-02

140

Gonadal- and Sex-Chromosome-Dependent Sex Differences in the Circadian System  

PubMed Central

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.

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

2013-01-01

141

Searching for sex-reversals to explain population demography and the evolution of sex chromosomes.  

PubMed

Sex determination can be purely genetic (as in mammals and birds), purely environmental (as in many reptiles), or genetic but reversible by environmental factors during a sensitive period in life, as in many fish and amphibians (Wallace et al. 1999; Baroiller et al. 2009a; Stelkens & Wedekind 2010). Such environmental sex reversal (ESR) can be induced, for example, by temperature changes or by exposure to hormone-active substances. ESR has long been recognized as a means to produce more profitable single-sex cultures in fish farms (Cnaani & Levavi-Sivan 2009), but we know very little about its prevalence in the wild. Obviously, induced feminization or masculinization may immediately distort population sex ratios, and distorted sex ratios are indeed reported from some amphibian and fish populations (Olsen et al. 2006; Alho et al. 2008; Brykov et al. 2008). However, sex ratios can also be skewed by, for example, segregation distorters or sex-specific mortality. Demonstrating ESR in the wild therefore requires the identification of sex-linked genetic markers (in the absence of heteromorphic sex chromosomes) followed by comparison of genotypes and phenotypes, or experimental crosses with individuals who seem sex reversed, followed by sexing of offspring after rearing under non-ESR conditions and at low mortality. In this issue, Alho et al. (2010) investigate the role of ESR in the common frog (Rana temporaria) and a population that has a distorted adult sex ratio. They developed new sex-linked microsatellite markers and tested wild-caught male and female adults for potential mismatches between phenotype and genotype. They found a significant proportion of phenotypic males with a female genotype. This suggests environmental masculinization, here with a prevalence of 9%. The authors then tested whether XX males naturally reproduce with XX females. They collected egg clutches and found that some had indeed a primary sex ratio of 100% daughters. Other clutches seemed to result from multi-male fertilizations of which at least one male had the female genotype. These results suggest that sex-reversed individuals affect the sex ratio in the following generation. But how relevant is ESR if its prevalence is rather low, and what are the implications of successful reproduction of sex-reversed individuals in the wild? PMID:20529067

Wedekind, Claus

2010-05-01

142

Risk of Chromosomal Abnormalities in Early Spontaneous Abortion after Assisted Reproductive Technology: A Meta-Analysis  

PubMed Central

Background Studies on the risk of chromosomal abnormalities in early spontaneous abortion after assisted reproductive technology (ART) are relatively controversial and insufficient. Thus, to obtain a more precise evaluation of the risk of embryonic chromosomal abnormalities in first-trimester miscarriage after ART, we performed a meta-analysis of all available case–control studies relating to the cytogenetic analysis of chromosomal abnormalities in first-trimester miscarriage after ART. Methods Literature search in the electronic databases MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) based on the established strategy. Meta-regression, subgroup analysis, and Galbraith plots were conducted to explore the sources of heterogeneity. Results A total of 15 studies with 1,896 cases and 1,186 controls relevant to the risk of chromosomal abnormalities in first- trimester miscarriage after ART, and 8 studies with 601 cases and 602 controls evaluating frequency of chromosome anomaly for maternal age?35 versus <35 were eligible for the meta-analysis. No statistical difference was found in risk of chromosomally abnormal miscarriage compared to natural conception and the different types of ART utilized, whereas the risk of fetal aneuploidy significantly increased with maternal age?35 (OR 2.88, 95% CI: 1.74–4.77). Conclusions ART treatment does not present an increased risk for chromosomal abnormalities occurring in a first trimester miscarriage, but incidence of fetal aneuploidy could increase significantly with advancing maternal age.

Qin, Jun-Zhen; Pang, Li-Hong; Li, Min-Qing; Xu, Jing; Zhou, Xing

2013-01-01

143

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

PubMed Central

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.

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

2012-01-01

144

A major locus on mouse chromosome 18 controls XX sex reversal in Odd Sex (Ods) mice.  

PubMed

We have previously reported a dominant mouse mutant, Odd sex (Ods), in which XX Ods/+ mice on the FVB/N background show complete sex reversal, associated with expression of Sox9 in the fetal gonads. Remarkably, when crossed to the A/J strain approximately 95% of the (AXFVB) F(1) XX Ods/+ mice developed as fully fertile, phenotypic females, the remainder developing as males or hermaphrodites. Using a (AXFVB) F(2) population, we conducted a genome-wide linkage scan to identify the number and chromosomal location of potential Ods modifier genes. A single major locus termed Odsm1 was mapped to chromosome 18, tightly linked to D18Mit189 and D18Mit210. Segregation at this locus could account for the presence of sex reversal in 100% of XX Ods/+ mice which develop as males, for the absence of sex reversal in approximately 92% of XX Ods/+ mice which develop as females, and for the mixed sexual phenotype in approximately 72% of XX Ods/+ mice that develop with ambiguous genitalia. We propose that homozygosity for the FVB-derived allele strongly favors Ods sex reversal, whereas homozygosity for the A/J-derived allele inhibits it. In mice heterozygous at Odsm1, the phenotypic outcome, male, female or hermaphrodite, is determined by a complex interaction of several minor modifying loci. The close proximity of Smad2, Smad7 and Smad4 to D18Mit189/210 provides a potential mechanism through which Odsm1 might act. PMID:12588798

Qin, Yangjun; Poirier, Christophe; Truong, Cavatina; Schumacher, Armin; Agoulnik, Alexander I; Bishop, Colin E

2003-03-01

145

Lack of dosage compensation accompanies the arrested stage of sex chromosome evolution in ostriches.  

PubMed

Sex chromosome evolution is usually seen as a process that, once initiated, will inevitably progress toward an advanced stage of degeneration of the nonrecombining chromosome. However, despite evidence that avian sex chromosome evolution was initiated >100 Ma, ratite birds have been trapped in an arrested stage of sex chromosome divergence. We performed RNA sequencing of several tissues from male and female ostriches and assembled the transcriptome de novo. A total of 315 Z-linked genes fell into two categories: those that have equal expression level in the two sexes (for which Z-W recombination still occurs) and those that have a 2-fold excess of male expression (for which Z-W recombination has ceased). We suggest that failure to evolve dosage compensation has constrained sex chromosome divergence in this basal avian lineage. Our results indicate that dosage compensation is a prerequisite for, not only a consequence of, sex chromosome evolution. PMID:23329687

Adolfsson, Sofia; Ellegren, Hans

2013-04-01

146

Lack of Dosage Compensation Accompanies the Arrested Stage of Sex Chromosome Evolution in Ostriches  

PubMed Central

Sex chromosome evolution is usually seen as a process that, once initiated, will inevitably progress toward an advanced stage of degeneration of the nonrecombining chromosome. However, despite evidence that avian sex chromosome evolution was initiated >100 Ma, ratite birds have been trapped in an arrested stage of sex chromosome divergence. We performed RNA sequencing of several tissues from male and female ostriches and assembled the transcriptome de novo. A total of 315 Z-linked genes fell into two categories: those that have equal expression level in the two sexes (for which Z–W recombination still occurs) and those that have a 2-fold excess of male expression (for which Z–W recombination has ceased). We suggest that failure to evolve dosage compensation has constrained sex chromosome divergence in this basal avian lineage. Our results indicate that dosage compensation is a prerequisite for, not only a consequence of, sex chromosome evolution.

Adolfsson, Sofia; Ellegren, Hans

2013-01-01

147

MMPI Profiles of Males with Abnormal Sex Chromosome Complements  

ERIC Educational Resources Information Center

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)

Rosen, M.; And Others

1971-01-01

148

The Contribution of Chromosomal Abnormalities to Congenital Heart Defects: A Population-Based Study  

Microsoft Academic Search

We aimed to assess the frequency of chromosomal abnormalities among infants with congenital heart defects (CHDs) in an analysis\\u000a of population-based surveillance data. We reviewed data from the Metropolitan Atlanta Congenital Defects Program, a population-based\\u000a birth-defects surveillance system, to assess the frequency of chromosomal abnormalities among live-born infants and fetal\\u000a deaths with CHDs delivered from January 1, 1994, to December

Robert J. Hartman; Sonja A. Rasmussen; Lorenzo D. Botto; Tiffany Riehle-Colarusso; Christa L. Martin; Janet D. Cragan; Mikyong Shin; Adolfo Correa

149

The identification of chromosome abnormalities associated with the invasive phenotype of uveal melanoma in vitro.  

PubMed

Tumour cell cultures are often highly heterogeneous, containing sub-populations of cells with differing characteristics. To identify chromosome abnormalities that are associated with the invasive phenotype, we isolated highly invasive uveal melanoma cell populations using the Transwell assay. Using this invasion assay, invasive sub-populations of primary uveal melanoma short-term cultures, and an established cell line, were specifically isolated. A series of sequential assays were undertaken to enrich the invasive population, and the enhanced invasive ability was confirmed by Transwell invasion assay. Chromosome abnormalities in invasive and parental cells were identified by karyotyping and confirmed by comparative genome hybridisation. Invasive sub-populations of uveal melanoma cells were isolated from 3 uveal melanoma short term cultures and a uveal melanoma cell line. In all cases, invasive sub-populations had either acquired additional chromosome abnormalities to those present in the parental cell line, or other abnormalities present in the parental lines were lost. In the established cell line (SOM 157), invasive cells were characterised by widespread chromosomal instability, frequent telomere associations and additional copies of chromosome 20. The invasive phenotype of SOM 196 associated with the presence of a derivative chromosome 5, der(5)t(5;11)(q35;q12) whilst a translocation t(17;20)(q12;q13) was predominant amongst non-invasive cells. In two additional cultures, deletions on chromosome 6q were associated with reduced invasive ability. In conclusion, highly invasive populations of uveal melanoma cells demonstrate chromosomal abnormalities that differ from non-invasive cells. These include chromosome instability and abnormalities of chromosome 20, observations echoing those seen in metastatic uveal melanoma. PMID:16086231

Cross, Neil A; Rennie, Ian G; Murray, Anna K; Sisley, Karen

2005-01-01

150

Cytogenetic studies of Hynobiidae (Urodela) XIX. Morphological variation of sex chromosomes pairing behavior of sex lampbrush chromosomes in Hynobius quelpaertensis (Mori) from Cheju Island, South Korea.  

PubMed

Using Giemsa staining, C-banding and Ag-NOR staining techniques, we analyzed chromosomes in adult male and female Hynobius quelpaertensis and in embryos of this species in egg sacs collected from eight localities of Cheju Island, South Korea. Chromosome pair 21 was consistently homomorphic in male specimens, while it was heteromorphic in female specimens, suggesting the occurrence of ZZ/ZW sex chromosome constitution in this species. The W chromosome, being much larger than the Z chromosome, was of three morphologically distinct types: WA, WB and WC. Lampbrush chromosomes examined in the oocytes of one female specimen having the WA chromosome showed that the short arm of the WA chromosome and the long arm of the Z chromosome paired closely and hence are genetically homologous. We also tried to analyze the structural relationship among the three types of W chromosomes based on their C-banding and Ag-NOR patterns. PMID:15861305

Ikebe, Chikako; Kuro-o, Masaki; Ohtani, Hiromi; Kawase, Yoshie; Matsui, Tomomi; Kohno, Sei-ichi

2005-01-01

151

Identification of the sex-determining locus of Atlantic salmon (Salmo salar) on chromosome 2.  

PubMed

We have integrated data from linkage mapping, physical mapping and karyotyping to gain a better understanding of the sex-determining locus, SEX, in Atlantic salmon (Salmo salar). SEX has been mapped to Atlantic salmon linkage group 1 (ASL1) and is associated with several microsatellite markers. We have used probes designed from the flanking regions of these sex-linked microsatellite markers to screen a bacterial artificial chromosome (BAC) library, representing an 11.7x coverage of the Atlantic salmon genome, which has been HindIII fingerprinted and assembled into contigs. BACs containing sex-linked microsatellites and their related contigs have been identified and representative BACs have been placed on the Atlantic salmon chromosomes by fluorescent in situ hybridization (FISH). This identified chromosome 2, a large metacentric, as the sex chromosome. By positioning several BACs on this chromosome by FISH, it was possible to orient ASL1 with respect to chromosome 2. The region containing SEX appears to lie on the long arm between marker Ssa202DU and a region of heterochromatin identified by DAPI staining. BAC end-sequencing of clones within sex-linked contigs revealed five hitherto unmapped genes along the sex chromosome. We are using an in silico approach coupled with physical probing of the BAC library to extend the BAC contigs to provide a physical map of ASL1, with a view to sequencing chromosome 2 and, in the process, identifying the sex-determining gene. PMID:16276105

Artieri, C G; Mitchell, L A; Ng, S H S; Parisotto, S E; Danzmann, R G; Hoyheim, B; Phillips, R B; Morasch, M; Koop, B F; Davidson, W S

2006-01-01

152

Spectral Karyotyping for identification of constitutional chromosomal abnormalities at a national reference laboratory  

PubMed Central

Spectral karyotyping is a diagnostic tool that allows visualization of chromosomes in different colors using the FISH technology and a spectral imaging system. To assess the value of spectral karyotyping analysis for identifying constitutional supernumerary marker chromosomes or derivative chromosomes at a national reference laboratory, we reviewed the results of 179 consecutive clinical samples (31 prenatal and 148 postnatal) submitted for spectral karyotyping. Over 90% of the cases were requested to identify either small supernumerary marker chromosomes (sSMCs) or chromosomal exchange material detected by G-banded chromosome analysis. We also reviewed clinical indications of those cases with marker chromosomes in which chromosomal origin was identified by spectral karyotyping. Our results showed that spectral karyotyping identified the chromosomal origin of marker chromosomes or the source of derivative chromosomal material in 158 (88%) of the 179 clinical cases; the identification rate was slightly higher for postnatal (89%) compared to prenatal (84%) cases. Cases in which the origin could not be identified had either a small marker chromosome present at a very low level of mosaicism (< 10%), or contained very little euchromatic material. Supplemental FISH analysis confirmed the spectral karyotyping results in all 158 cases. Clinical indications for prenatal cases were mainly for marker identification after amniocentesis. For postnatal cases, the primary indications were developmental delay and multiple congenital anomalies (MCA). The most frequently encountered markers were of chromosome 15 origin for satellited chromosomes, and chromosomes 2 and 16 for non-satellited chromosomes. We were able to obtain pertinent clinical information for 47% (41/88) of cases with an identified abnormal chromosome. We conclude that spectral karyotyping is sufficiently reliable for use and provides a valuable diagnostic tool for establishing the origin of supernumerary marker chromosomes or derivative chromosomal material that cannot be identified with standard cytogenetic techniques.

2012-01-01

153

Gain of chromosome 17 is the most frequent abnormality detected in neuroblastoma by comparative genomic hybridization.  

PubMed Central

Neuroblastoma behavior is variable and outcome partially depends on genetic factors. However, tumors that lack high-risk factors such as MYCN amplification or 1p deletion may progress, possibly due to other genetic aberrations. Comparative genomic hybridization summarizes DNA copy number abnormalities in a tumor by mapping them to their positions on normal metaphase chromosomes. We analyzed 29 tumors from nearly equal proportions of children with stage I, II, III, IV, and IV-S disease by comparative genomic hybridization. We found two classes of copy number abnormalities: whole chromosome and partial chromosome. Whole chromosome losses were frequent at 11, 14, and X. The most frequent partial chromosome losses were on 1p and 11q. Gains were most frequent on chromosome 17 (72% of cases). The two patterns of gain for this chromosome were whole 17 gain and 17q gain, with 17q21-qter as a minimal common region of gain. Other common gains were on chromosomes 7, 6, and 18. High level amplifications were detected at 2p23-25 (MYCN region), at 4q33-35, and at 6p11-22. Chromosome 17q gains were associated with 1p and/or 11q deletions and advanced stage. The high frequency of chromosome 17 gain and its association with bad prognostic factors suggest an important role for this chromosome in the development of neuroblastoma.

Plantaz, D.; Mohapatra, G.; Matthay, K. K.; Pellarin, M.; Seeger, R. C.; Feuerstein, B. G.

1997-01-01

154

Meiotic Pairing and Segregation of Achiasmate Sex Chromosomes in Eutherian Mammals: The Role of SYCP3 Protein  

Microsoft Academic Search

In most eutherian mammals, sex chromosomes synapse and recombine during male meiosis in a small region called pseudoautosomal region. However in some species sex chromosomes do not synapse, and how these chromosomes manage to ensure their proper segregation is under discussion. Here we present a study of the meiotic structure and behavior of sex chromosomes in one of these species,

Roberto de la Fuente; María Teresa Parra; Alberto Viera; Adela Calvente; Rocío Gómez; José Ángel Suja; Julio S Rufas; Jesús Page

2007-01-01

155

LEOPARD syndrome with partly normal skin and sex chromosome mosaicism.  

PubMed

We report on a family with LEOPARD syndrome which was molecularly proven (p.Thr468Met in PTPN11) in a father and his adult son. The father had multiple lentigines dispersed equally over his body; the son was similarly affected except for the left part of thorax, back and left arm, which were completely devoid of lentigines and only showed a few nevi. In addition, the son was found to have a mosaic karyotype, 47,XYY/46,XY, in lymphocytes. Skin biopsies from the pigmented and unpigmented forearm showed that mainly a 47,XYY karyotype was present in the pigmented skin and mainly a 46,XY karyotype in the unpigmented skin. In both fibroblast cultures the PTPN11 mutation was present, and no additional mutation could be detected. We discuss the various possible explanations for this phenotype, which include the possibility of coincidence; revertant mosaicism; silencing of a second PTPN11 mutation; gene(s) located on a sex chromosome influencing the phenotype; and epigenetic influences. We favor that the co-occurrence of a sex chromosome mosaicism and mosaicism for skin symptoms in a single patient with LEOPARD syndrome is coincidence, but that mosaicism for LEOPARD skin symptoms in itself may well be more frequent and needs additional studies. Each of the above-hypothesized mechanisms may then remain possible. PMID:17935252

Writzl, Karin; Hoovers, Jan; Sistermans, Erik A; Hennekam, Raoul C M

2007-11-01

156

Sex chromosome turnover contributes to genomic divergence between incipient stickleback species.  

PubMed

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

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

2014-03-01

157

Sex Chromosome Turnover Contributes to Genomic Divergence between Incipient Stickleback Species  

PubMed Central

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.

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

158

The origin and evolution of vertebrate sex chromosomes and dosage compensation  

Microsoft Academic Search

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

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

2012-01-01

159

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.

160

Dynamic transposable element accumulation in the nascent sex chromosomes of papaya  

PubMed Central

From their inception, Y chromosomes in plants and animals are subjected to the powerful effects of Müller’s ratchet, a process spurred by suppression of recombination that results in a rapid accumulation of mutations and repetitive elements. These mutations eventually lead to gene loss and degeneration of the Y chromosome. Y chromosomes in mammals are ancient, whereas most sex chromosomes in plants and many in insects and fish evolved recently. Sex type in papaya is controlled by a pair of nascent sex chromosomes that evolved around 7 million years ago. The papaya X and Yh were recently sequenced, providing valuable insight into the early stages of sex chromosome evolution. Here we discuss the fruits of this work with a focus on the repeat accumulation, gene trafficking and promiscuous DNA sequences found in the slowly degenerating Yh chromosome of papaya.

VanBuren, Robert; Ming, Ray

2013-01-01

161

Dynamic transposable element accumulation in the nascent sex chromosomes of papaya.  

PubMed

From their inception, Y chromosomes in plants and animals are subjected to the powerful effects of Müller's ratchet, a process spurred by suppression of recombination that results in a rapid accumulation of mutations and repetitive elements. These mutations eventually lead to gene loss and degeneration of the Y chromosome. Y chromosomes in mammals are ancient, whereas most sex chromosomes in plants and many in insects and fish evolved recently. Sex type in papaya is controlled by a pair of nascent sex chromosomes that evolved around 7 million years ago. The papaya X and Y(h) were recently sequenced, providing valuable insight into the early stages of sex chromosome evolution. Here we discuss the fruits of this work with a focus on the repeat accumulation, gene trafficking and promiscuous DNA sequences found in the slowly degenerating Y(h) chromosome of papaya. PMID:23734293

Vanburen, Robert; Ming, Ray

2013-01-01

162

Structural Chromosome Abnormalities Associated with Obesity: Report of Four New subjects and Review of Literature  

PubMed Central

Obesity in humans is a complex polygenic trait with high inter-individual heritability estimated at 40–70%. Candidate gene, DNA linkage and genome-wide association studies (GWAS) have allowed for the identification of a large set of genes and genomic regions associated with obesity. Structural chromosome abnormalities usually result in congenital anomalies, growth retardation and developmental delay. Occasionally, they are associated with hyperphagia and obesity rather than growth delay. We report four new individuals with structural chromosome abnormalities involving 10q22.3-23.2, 16p11.2 and Xq27.1-q28 chromosomal regions with early childhood obesity and developmental delay. We also searched and summarized the literature for structural chromosome abnormalities reported in association with childhood obesity.

Dasouki, Majed J; Youngs, Erin L; Hovanes, Karine

2011-01-01

163

Genome-Wide Gene Expression Effects of Sex Chromosome Imprinting in Drosophila  

PubMed Central

Imprinting is well-documented in both plant and animal species. In Drosophila, the Y chromosome is differently modified when transmitted through the male and female germlines. Here, we report genome-wide gene expression effects resulting from reversed parent-of-origin of the X and Y chromosomes. We found that hundreds of genes are differentially expressed between adult male Drosophila melanogaster that differ in the maternal and paternal origin of the sex chromosomes. Many of the differentially regulated genes are expressed specifically in testis and midgut cells, suggesting that sex chromosome imprinting might globally impact gene expression in these tissues. In contrast, we observed much fewer Y-linked parent-of-origin effects on genome-wide gene expression in females carrying a Y chromosome, indicating that gene expression in females is less sensitive to sex chromosome parent-of-origin. Genes whose expression differs between females inheriting a maternal or paternal Y chromosome also show sex chromosome parent-of-origin effects in males, but the direction of the effects on gene expression (overexpression or underexpression) differ between the sexes. We suggest that passage of sex chromosome chromatin through male meiosis may be required for wild-type function in F1 progeny, whereas disruption of Y-chromosome function through passage in the female germline likely arises because the chromosome is not adapted to the female germline environment.

Lemos, Bernardo; Branco, Alan T.; Jiang, Pan-Pan; Hartl, Daniel L.; Meiklejohn, Colin D.

2013-01-01

164

A large pseudoautosomal region on the sex chromosomes of the frog Silurana tropicalis.  

PubMed

Sex chromosome divergence has been documented across phylogenetically diverse species, with amphibians typically having cytologically nondiverged ("homomorphic") sex chromosomes. With an aim of further characterizing sex chromosome divergence of an amphibian, we used "RAD-tags" and Sanger sequencing to examine sex specificity and heterozygosity in the Western clawed frog Silurana tropicalis (also known as Xenopus tropicalis). Our findings based on approximately 20 million genotype calls and approximately 200 polymerase chain reaction-amplified regions across multiple male and female genomes failed to identify a substantially sized genomic region with genotypic hallmarks of sex chromosome divergence, including in regions known to be tightly linked to the sex-determining region. We also found that expression and molecular evolution of genes linked to the sex-determining region did not differ substantially from genes in other parts of the genome. This suggests that the pseudoautosomal region, where recombination occurs, comprises a large portion of the sex chromosomes of S. tropicalis. These results may in part explain why African clawed frogs have such a high incidence of polyploidization, shed light on why amphibians have a high rate of sex chromosome turnover, and raise questions about why homomorphic sex chromosomes are so prevalent in amphibians. PMID:23666865

Bewick, Adam J; Chain, Frédéric J J; Zimmerman, Lyle B; Sesay, Abdul; Gilchrist, Michael J; Owens, Nick D L; Seifertova, Eva; Krylov, Vladimir; Macha, Jaroslav; Tlapakova, Tereza; Kubickova, Svatava; Cernohorska, Halina; Zarsky, Vojtech; Evans, Ben J

2013-01-01

165

A Large Pseudoautosomal Region on the Sex Chromosomes of the Frog Silurana tropicalis  

PubMed Central

Sex chromosome divergence has been documented across phylogenetically diverse species, with amphibians typically having cytologically nondiverged (“homomorphic”) sex chromosomes. With an aim of further characterizing sex chromosome divergence of an amphibian, we used “RAD-tags” and Sanger sequencing to examine sex specificity and heterozygosity in the Western clawed frog Silurana tropicalis (also known as Xenopus tropicalis). Our findings based on approximately 20 million genotype calls and approximately 200 polymerase chain reaction-amplified regions across multiple male and female genomes failed to identify a substantially sized genomic region with genotypic hallmarks of sex chromosome divergence, including in regions known to be tightly linked to the sex-determining region. We also found that expression and molecular evolution of genes linked to the sex-determining region did not differ substantially from genes in other parts of the genome. This suggests that the pseudoautosomal region, where recombination occurs, comprises a large portion of the sex chromosomes of S. tropicalis. These results may in part explain why African clawed frogs have such a high incidence of polyploidization, shed light on why amphibians have a high rate of sex chromosome turnover, and raise questions about why homomorphic sex chromosomes are so prevalent in amphibians.

Bewick, Adam J.; Chain, Frederic J.J.; Zimmerman, Lyle B.; Sesay, Abdul; Gilchrist, Michael J.; Owens, Nick D.L.; Seifertova, Eva; Krylov, Vladimir; Macha, Jaroslav; Tlapakova, Tereza; Kubickova, Svatava; Cernohorska, Halina; Zarsky, Vojtech; Evans, Ben J.

2013-01-01

166

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

PubMed Central

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.

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

2012-01-01

167

Possible causes of chromosome instability: comparison of chromosomal abnormalities in cancer cell lines with mutations in BRCA1, BRCA2, CHK2 and BUB1  

Microsoft Academic Search

A large proportion of epithelial cancers show the chromosome-instability phenotype, in which they have many chromosome abnormalities. This is thought to be the result of mutations that disrupt chromosome maintenance, but the causative mutations are not known. We identified cell lines known to have mutations that might cause chromosome instability, and examined their karyotypes. Two cell lines, the breast cancer

M. Grigorova; J. M. Staines; H. Ozdag; C. Caldas; P. A. W. Edwards

2004-01-01

168

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

PubMed

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

Sánchez, L

2014-01-01

169

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

PubMed

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

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

2012-07-01

170

Chromosomal Abnormalities and Y Chromosome Microdeletions in Infertile Men With Varicocele and Idiopathic Infertility of South Indian Origin  

Microsoft Academic Search

Various factors cause spermatogenesis arrest in men and, in a large number of cases, the underlying reason still remains unknown. Little attention is paid to determining the genetic defects of varicocele-related infertility. The objective of our present study was to investigate the chromosomal abnormalities and Y chromo- some microdeletions in infertile men of South Indian origin with var- icocele and

LAKSHMI RAO; ARVIND BABU; MURTHY KANAKAVALLI; VENKATA PADMALATHA; AMARPAL SINGH; PRASHANT KUMAR SINGH; MAMATA DEENADAYAL; LALJI SINGH

171

Interchromosomal Duplications on the Bactrocera oleae Y Chromosome Imply a Distinct Evolutionary Origin of the Sex Chromosomes Compared to Drosophila  

PubMed Central

Background Diptera have an extraordinary variety of sex determination mechanisms, and Drosophila melanogaster is the paradigm for this group. However, the Drosophila sex determination pathway is only partially conserved and the family Tephritidae affords an interesting example. The tephritid Y chromosome is postulated to be necessary to determine male development. Characterization of Y sequences, apart from elucidating the nature of the male determining factor, is also important to understand the evolutionary history of sex chromosomes within the Tephritidae. We studied the Y sequences from the olive fly, Bactrocera oleae. Its Y chromosome is minute and highly heterochromatic, and displays high heteromorphism with the X chromosome. Methodology/Principal Findings A combined Representational Difference Analysis (RDA) and fluorescence in-situ hybridization (FISH) approach was used to investigate the Y chromosome to derive information on its sequence content. The Y chromosome is strewn with repetitive DNA sequences, the majority of which are also interdispersed in the pericentromeric regions of the autosomes. The Y chromosome appears to have accumulated small and large repetitive interchromosomal duplications. The large interchromosomal duplications harbour an importin-4-like gene fragment. Apart from these importin-4-like sequences, the other Y repetitive sequences are not shared with the X chromosome, suggesting molecular differentiation of these two chromosomes. Moreover, as the identified Y sequences were not detected on the Y chromosomes of closely related tephritids, we can infer divergence in the repetitive nature of their sequence contents. Conclusions/Significance The identification of Y-linked sequences may tell us much about the repetitive nature, the origin and the evolution of Y chromosomes. We hypothesize how these repetitive sequences accumulated and were maintained on the Y chromosome during its evolutionary history. Our data reinforce the idea that the sex chromosomes of the Tephritidae may have distinct evolutionary origins with respect to those of the Drosophilidae and other Dipteran families.

Gabrieli, Paolo; Gomulski, Ludvik M.; Bonomi, Angelica; Siciliano, Paolo; Scolari, Francesca; Franz, Gerald; Jessup, Andrew; Malacrida, Anna R.; Gasperi, Giuliano

2011-01-01

172

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

SciTech Connect

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.

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

1994-09-01

173

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

174

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

PubMed Central

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.

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

2012-01-01

175

No prognostic effect of additional chromosomal abnormalities in children with acute lymphoblastic leukemia and 11q23 abnormalities  

Microsoft Academic Search

This study characterized the additional chromosomal abnormalities (ACA) associated with 11q23 rearrangements in 450 infants and children with acute lymphoblastic leukemia (ALL) and examined the impact of these ACA on survival. Overall, 213 (47%) cases had ACA but the incidence varied according to patient age and 11q23 subgroup. Infants and patients with t(4;11)(q21;q23) had the lowest incidence of ACA (50\\/182

A V Moorman; S C Raimondi; C-H Pui; A Baruchel; A Biondi; A J Carroll; E Forestier; P S Gaynon; J Harbott; D O Harms; N Heerema; R Pieters; M Schrappe; L B Silverman; E Vilmer; C J Harrison

2005-01-01

176

Chromosomal abnormalities in Day-6, in vitro-produced pig embryos.  

PubMed

A cytogenetic study was undertaken to quantify, by chromosomal karyotyping, the incidence and type of chromosomal abnormalities present in Day-6 in vitro-produced (IVP) porcine embryos. Morphologically normal Day-6 blastocysts (n=318) were fixed and grouped into six classes according to the number of total cells (from < or =20 to 61-70). Of 248 embryos suitable for analysis, 97 (39.1%) displayed chromosomal abnormalities. The abnormalities included haploidy (9.3%), polyploidy (71.1%) and mixoploidy (19.6%). Within polyploid embryos, triploidy and tetraploidy showed the highest incidence (56.5 and 27.5%, respectively); among mixoploid embryos, diploid-triploid embryos (2n/3n) were prevalent (36.8%). Overall, the mean cell number was 34.3 +/- 12.1 and the mitotic index was 8.6 +/- 6.1. Chromosomally abnormal embryos had fewer (P<0.01) total cells compared to normal (2n) embryos (31.8 +/- 1.3 versus 35.9 +/- 1.0). In addition, the incidence of polyploidy decreased as the number of cells increased, while that of mixoploidy did not differ. These data indicate that polyploidy affects a large percentage of IVP porcine embryos capable of developing to blastocysts and the incidence of chromosomal abnormalities is much higher than that reported previously in in vivo embryos in this species. Given the ability of morphologically normal embryos with an abnormal chromosome complement to undergo preimplantation development in vitro, and the inability to identify blastocysts with abnormal karyotype without cytogenetic analysis, careful consideration should be given to factors affecting ploidy of IVP embryos, especially the incidence of polyspermic fertilization, when evaluating criteria of a porcine in vitro embryo production scheme. PMID:14519476

McCauley, Tod C; Mazza, M R; Didion, Brad A; Mao, J; Wu, G; Coppola, G; Coppola, G F; Di Berardino, D; Day, Billy N

2003-11-01

177

The evolution of a neo-XY1Y2 sex chromosome system by autosome-sex chromosome fusion in Dundocoris nodulicarinus Jacobs (Heteroptera: Aradidae: Carventinae).  

PubMed

Sibling subspecies of Dundocoris nodulicarinus, inhabiting different isolated indigenous evergreen forests in South Africa, have chromosome numbers of 2n(male) = 14XY, 9XY1Y2 and 7XY1Y2. The ancestral chromosome number of Dundocoris is probably 2n(male) = 28XY and several chromosome fusions were involved in the karyotype evolution of these taxa. The XY1Y2 sex chromosome system of the 9XY1Y2 D. nodulicarinus novenus originated by the fusion of a large autosome with the X-chromosome, forming a neo-X with the homologue of the fused autosome forming the neo-Y (=Y1) and the original Y-chromosome, the Y2. While the original X- and Y-chromosomes are heterochromatic and heteropycnotic during prophase I, the autosomal part of the neo-X and the neo-Y stay euchromatic and behave like a normal autosomal pair, forming synapsis and chiasmata. The XY1Y2 sex chromosome system of the 7XY1Y2 D. nodulicarinus septeni probably originated from the 9XY1Y2 karyotype when the homologous chromosomes of a small autosomal pair fused with the original X- and Y-chromosomes, respectively. In both the subspecies with the neo-XY1Y2 systems, the original sex chromosomes still undergo chromatid segregation at anaphase I (= post-reductional). The evolution and behaviour of the karyotypes and sex chromosome systems during the course of meiosis in the subspecies of D. nodulicarinus are described, discussed and illustrated. PMID:15053487

Jacobs, D H

2004-01-01

178

Consistent Chromosome Abnormalities in Adenocarcinoma of the Pancreas1  

Microsoft Academic Search

Little is known about the somatic genetic changes which characterize pancreatic adenocarcinoma. The identification of acquired genomic alter ations would further our understanding of the biology of this neoplasm. We have studied 62 primary pancreatic adenocarcinomas obtained from surgical resections using classical cytogenetics and fluorescent in situ hybridization methods. Clonally abnormal karyotypes were observed in 44 neoplasms. Karyotypes were generally

Constance A. Griffin; Ralph H. Hruban; Laura A. Morsberger; Tara Ellingham; Patricia P. Long; Elizabeth M. Jaffee; Karen M. Hauda; Stefan K. Bohlander; Charles J. Yeo

179

Sex chromosome meiotic drive in hybrid males of the common shrew (Sorex araneus).  

PubMed

Patterns of sex chromosome segregation in six homozygous males of the common shrew (Sorex araneus LINNAEUS, 1758) belonging to two chromosomal races, as well as in 16 interracial hybrids were studied. Based on their karyotypes the hybrids can be subdivided into two groups: (a) complex heterozygotes, which form meiotic quadrivalents in chain and chain + ring configurations, and (b) complex heterozygotes, which form meiotic pentavalents in chain configurations. Random (1:1) segregation of sex chromosomes was found in homozygous as well as those heterozygous males which form meiotic complexes of four chromosomes. However, in some hybrids with meiotic pentavalents we observed a strong preferential segregation in favour of X chromosomes. PMID:19058534

Fedyk, Stanis?aw; Bajkowska, Urszula; Chetnicki, W?odzimierz

2005-01-01

180

Analysis of repetitive DNA sequences in the sex chromosomes of Oreochromis niloticus  

Microsoft Academic Search

In the Nile tilapia, Oreochromis niloticus, sex determination is primarily genetic, with XX females and XY males. While the X and Y chromosomes (the largest pair) cannot be distinguished in mitotic chromosome spreads, analysis of comparative hybridization of X and Y chromosome derived probes (produced, by microdissection and DOP-PCR, from XX and YY genotypes, respectively) to different genotypes (XX, XY

S. C. Harvey; C. Boonphakdee; R. Campos-Ramos; M. T. Ezaz; D. K. Griffin; N. R. Bromage; P Penman

2003-01-01

181

Aberrant chromosomal sex-determining mechanisms in mammals, with special reference to species with XY females.  

PubMed

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/XY1Y2 and X1X1X2X2/X1X2Y. The original X or the Y, respectively, have been translocated on to an autosome. The sex chromosomes of these species segregate regularly at meiosis; two kinds of sperm and one kind of egg are produced and the sex ratio is the normal 1:1. Individuals with deviating sex chromosome constitutions (XXY, XYY, XO or XXX) have been found in at least 16 mammalian species other than man. The phenotypic manifestations of these deviating constitutions are briefly discussed. In the dog, pig, goat and mouse exceptional XX males and in the horse XY females attract attention. Certain rodents have complicated mechanisms for sex determination: Ellobius lutescens and Tokudaia osimensis have XO males and females. Both sexes of Microtus oregoni are gonosomic mosaics (male OY/XY, female XX/XO). The wood lemming, Myopus schisticolor, the collared lemming, Dirostonyx torquatus, and perhaps also one or two species of the genus Akodon have XX and XY females and XY males. The XX, X*X and X*Y females of Myopus and Dicrostonyx are discussed in some detail. The wood lemming has proved to be a favourable natural model for studies in sex determination, because a large variety of sex chromosome aneuploids are born relatively frequently. The dosage model for sex determination is not supported by the wood lemming data. For male development, genes on both the X and the Y chromosomes are necessary. PMID:2907806

Fredga, K

1988-12-01

182

Chromosome abnormalities in Down's syndrome patients with acute leukemia  

SciTech Connect

Chromosome and cytologic studies were performed on three Down's syndrome (DS) patients with acute nonlymphocytic leukemia (ANLL). All three patients had an aneuploid clone in their leukemic cells: 50,XX, +6, +19, +21, +22, 48,XX, +8, +21, and 47,XY, +8, -21, +dic(21;21)(p13;p11). Every patient appeared to have acute undifferentiated leukemia when the blast cells were examined with Wright-Giemsa stain; cytochemistry studies, however, showed that the leukemic blasts were in an early stage of myeloid differentation. The two patients with +8 had a preleukemic phase; the blast cells of the patient with an extra no. 19 and no. 22 could not be differentiated morphologically from those of the two patients with an extra no. 8. Our findings and a review of data on 40 other patients suggest that most DS children with ANLL have hyperdiploidy, which is usually related to gains of C, F, and/or G chromosomes.

Kaneko, Y. (Univ. of Chicago, IL); Rowley, J.D.; Variakojis, D; Chilcote, R.R.; Moohr, J.W.; Patel, D.

1981-09-01

183

Abnormal chromosome 22 and recurrence of trisomy-22 syndrome.  

PubMed Central

Trisomy-22 was confirmed with both Q- and G-banding in two sibs. Growth and mental retardation plus various dysmorphic features of this syndrome are described and compared with previous reports. Cytogenetic studies reveal a morphologically atypical No. 22 in cells of the phenotypically normal mother (46,XX) and in both affected children. The variant G chromosome is identified as No. 22 by Q- and G-banding and is interpreted as a product of a pericentric inversion on the basis of general length, arm ratio (1.4), and anomalous satellite association frequency. Repeated nondisjunction for No. 22 is considered to have resulted from asynapsis caused by interference of an inversion loop configuration which, though short, comprised a major part of chromosome 22. Images

Emanuel, B S; Zackai, E H; Aronson, M M; Mellman, W J; Moorhead, P S

1976-01-01

184

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

PubMed

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 (and Zs and Ws) within species demonstrates that differentiated sex chromosomes were once homologous, and that the sex-specific non-recombining Y (or W) was progressively degraded. Consequently, genes are left in single copy in the heterogametic sex, which results in an imbalance of the dosage of genes on the sex chromosomes between the sexes, and also relative to the autosomes. Dosage compensation has evolved in diverse species to compensate for these dose differences, with the stringency of compensation apparently differing greatly between lineages, perhaps reflecting the concentration of genes on the original autosome pair that required dosage compensation. We discuss the organization and evolution of amniote sex chromosomes, and hypothesize that dosage insensitivity might predispose an autosome to evolving function as a sex chromosome. PMID:22086077

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

2012-01-01

185

Frequent Nonrandom Chromosome Abnormalities in 27 Patients with Untreated Large Cell Lymphoma and Immunoblastic Lymphoma1  

Microsoft Academic Search

Fresh tumor samples from 27 patients with large cell lymphoma, either previously untreated (26 patients) or minimally treated (one patient), were processed for cytogenetic studies. Cytogenetic abnormalities were observed in all patients, most commonly in chromosomes 1, 3, 7, 12, 14, 17, and 18. Nine chromosomal breakpoints appeared frequently: 14q32 in 14 instances; 18q21 in seven; 9pl3-21, 17pll-13, and 3q21-23

Fernando Cabanillas; Sen Pathak; Jose Trujillo; John Manning; Ruth Katz; Peter McLaughlin; William S. Velasquez; Fredrick B. Hagemeister; Angela Goodacre; Ann Cork; James J. Butler; J Freireich

186

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

Microsoft Academic Search

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

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

1995-01-01

187

Hypoxia-Induced Reactive Oxygen Species Cause Chromosomal Abnormalities in Endothelial Cells in the Tumor Microenvironment  

PubMed Central

There is much evidence that hypoxia in the tumor microenvironment enhances tumor progression. In an earlier study, we reported abnormal phenotypes of tumor-associated endothelial cells such as those resistant to chemotherapy and chromosomal instability. Here we investigated the role of hypoxia in the acquisition of chromosomal abnormalities in endothelial cells. Tumor-associated endothelial cells isolated from human tumor xenografts showed chromosomal abnormalities, >30% of which were aneuploidy. Aneuploidy of the tumor-associated endothelial cells was also shown by simultaneous in-situ hybridization for chromosome 17 and by immunohistochemistry with anti-CD31 antibody for endothelial staining. The aneuploid cells were surrounded by a pimonidazole-positive area, indicating hypoxia. Human microvascular endothelial cells expressed hypoxia-inducible factor 1 and vascular endothelial growth factor A in response to either hypoxia or hypoxia-reoxygenation, and in these conditions, they acquired aneuploidy in 7 days. Induction of aneuploidy was inhibited by either inhibition of vascular endothelial growth factor signaling with vascular endothelial growth factor receptor 2 inhibitor or by inhibition of reactive oxygen species by N-acetyl-L-cysteine. These results indicate that hypoxia induces chromosomal abnormalities in endothelial cells through the induction of reactive oxygen species and excess signaling of vascular endothelial growth factor in the tumor microenvironment.

Hida, Yasuhiro; Maishi, Nako; Towfik, Alam Mohammad; Inoue, Nobuo; Shindoh, Masanobu; Hida, Kyoko

2013-01-01

188

Evidence for Different Origins of Sex Chromosomes in Closely Related Oryzias Fishes: Substitution of the Master Sex-Determining Gene  

PubMed Central

The medaka Oryzias latipes and its two sister species, O. curvinotus and O. luzonensis, possess an XX–XY sex-determination system. The medaka sex-determining gene DMY has been identified on the orthologous Y chromosome [O. latipes linkage group 1 (LG1)] of O. curvinotus. However, DMY has not been discovered in other Oryzias species. These results and molecular phylogeny suggest that DMY was generated recently [?10 million years ago (MYA)] by gene duplication of DMRT1 in a common ancestor of O. latipes and O. curvinotus. We identified seven sex-linked markers from O. luzonensis (sister species of O. curvinotus) and constructed a sex-linkage map. Surprisingly, all seven sex-linked markers were located on an autosomal linkage group (LG12) of O. latipes. As suggested by the phylogenetic tree, the sex chromosomes of O. luzonensis should be “younger” than those of O. latipes. In the lineage leading to O. luzonensis after separation from O. curvinotus ?5 MYA, a novel sex-determining gene may have arisen and substituted for DMY. Oryzias species should provide a useful model for evolution of the master sex-determining gene and differentiation of sex chromosomes from autosomes.

Tanaka, Keita; Takehana, Yusuke; Naruse, Kiyoshi; Hamaguchi, Satoshi; Sakaizumi, Mitsuru

2007-01-01

189

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

PubMed

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

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

2014-07-01

190

Pachytene asynapsis drives meiotic sex chromosome inactivation and leads to substantial postmeiotic repression in spermatids.  

PubMed

Transcriptional silencing of the sex chromosomes during male meiosis (MSCI) is conserved among organisms with limited sex chromosome synapsis, including mammals. Since the 1990s the prevailing view has been that MSCI in mammals is transient, with sex chromosome reactivation occurring as cells exit meiosis. Recently, we found that any chromosome region unsynapsed during pachytene of male and female mouse meiosis is subject to transcriptional silencing (MSUC), and we hypothesized that MSCI is an inevitable consequence of this more general meiotic silencing mechanism. Here, we provide direct evidence that asynapsis does indeed drive MSCI. We also show that a substantial degree of transcriptional repression of the sex chromosomes is retained postmeiotically, and we provide evidence that this postmeiotic repression is a downstream consequence of MSCI/MSUC. While this postmeiotic repression occurs after the loss of MSUC-related proteins at the end of prophase, other histone modifications associated with transcriptional repression have by then become established. PMID:16580996

Turner, James M A; Mahadevaiah, Shantha K; Ellis, Peter J I; Mitchell, Michael J; Burgoyne, Paul S

2006-04-01

191

Risk of gonadoblastoma in female patients with Y chromosome abnormalities and dysgenetic gonads.  

PubMed

We report two female patients with gonadal dysgenesis and sex chromosome mosaicism involving the Y chromosome. Conventional karyotyping was supplemented with fluorescent in situ hybridisation techniques in order to confirm the presence of Y chromosomes. One patient is a phenotypic female with karyotype 45,X/46,X,idic(Y)(q11.2). She underwent a laparoscopic gonadectomy at which streak ovaries without evidence of gonadoblastoma were removed. The second patient presented as a virilised female with karyotype 45,X/47,XYY. At laparoscopy, she was found to have mixed gonadal dysgenesis with a gonadoblastoma in situ. We recommend early gonadectomy in female children presenting with gonadal dysgenesis and the presence of a Y chromosome although once the gonadoblastoma locus on Y chromosome gene has been cloned it may be possible to identify those patients who have a low risk of developing gonadoblastoma. PMID:10365364

Gibbons, B; Tan, S Y; Yu, C C; Cheah, E; Tan, H L

1999-04-01

192

XX male sex reversal with genital abnormalities associated with a de novo SOX3 gene duplication.  

PubMed

Differentiation of the bipotential gonad into testis is initiated by the Y chromosome-linked gene SRY (Sex-determining Region Y) through upregulation of its autosomal direct target gene SOX9 (Sry-related HMG box-containing gene 9). Sequence and chromosome homology studies have shown that SRY most probably evolved from SOX3, which in humans is located at Xq27.1. Mutations causing SOX3 loss-of-function do not affect the sex determination in mice or humans. However, transgenic mouse studies have shown that ectopic expression of Sox3 in the bipotential gonad results in upregulation of Sox9, resulting in testicular induction and XX male sex reversal. However, the mechanism by which these rearrangements cause sex reversal and the frequency with which they are associated with disorders of sex development remains unclear. Rearrangements of the SOX3 locus were identified recently in three cases of human XX male sex reversal. We report on a case of XX male sex reversal associated with a novel de novo duplication of the SOX3 gene. These data provide additional evidence that SOX3 gain-of-function in the XX bipotential gonad causes XX male sex reversal and further support the hypothesis that SOX3 is the evolutionary antecedent of SRY. PMID:22678921

Moalem, Sharon; Babul-Hirji, Riyana; Stavropolous, Dmitri J; Wherrett, Diane; Bägli, Darius J; Thomas, Paul; Chitayat, David

2012-07-01

193

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

SciTech Connect

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.

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

1994-01-01

194

No prognostic effect of additional chromosomal abnormalities in children with acute lymphoblastic leukemia and 11q23 abnormalities.  

PubMed

This study characterized the additional chromosomal abnormalities (ACA) associated with 11q23 rearrangements in 450 infants and children with acute lymphoblastic leukemia (ALL) and examined the impact of these ACA on survival. Overall, 213 (47%) cases had ACA but the incidence varied according to patient age and 11q23 subgroup. Infants and patients with t(4;11)(q21;q23) had the lowest incidence of ACA (50/182 (27%) and 57/216 (26%) respectively), whereas patients with del(11)(q23) had the highest incidence (66/93 (71%)). Del(11)(q23) abnormalities were heterogeneous and occasionally secondary to t(9;22)(q34;q11.2). Thus, patients with del(11)(q23) comprised a separate biological entity, which was clearly distinct from those with an 11q23 translocation. The most frequent specific ACA were trisomy X (n = 38), abnormal 12p (n = 32), abnormal 9p (n = 28) and del(6q) (n = 19). The presence of ACA did not change the 5 year event-free survival estimates among children (56% (95% Cl 46-65%) vs 62% (54-69%)) or infants (22% (15-29%) vs 18% (9-29%)), nor when the different 11q23 subgroups were analyzed separately. This study has conclusively demonstrated that there is no prognostic effect of secondary chromosomal changes in association with 11q23 abnormalities in childhood ALL. However, characterization of these ACA is important to determine their potential role in initiation of MLL driven leukemogenesis. PMID:15744345

Moorman, A V; Raimondi, S C; Pui, C H; Baruchel, A; Biondi, A; Carroll, A J; Forestier, E; Gaynon, P S; Harbott, J; Harms, D O; Heerema, N; Pieters, R; Schrappe, M; Silverman, L B; Vilmer, E; Harrison, C J

2005-04-01

195

Meiosis-specific protein selectively associated with sex chromosomes of rat pachytene spermatocytes.  

PubMed Central

During the first meiotic prophase of mammalian spermatogenesis, the sex chromosomes X and Y show a characteristic allocyclic behavior with respect to the autosomes. This is particularly evident during pachytene stage when sex chromosomes form the so-called sex vesicle. This structure is characterized by the condensed state of chromatin, transcriptional inactivity, and the limited extension of chromosome pairing, which is usually restricted to a short segment of sex chromosome axial elements. The molecular basis and functional significance of sex vesicle formation during mammalian spermatogenesis remain obscure. Here we report on the identification of a meiosis-specific sex vesicle protein we called XY40. Immunocytochemical localization on rat testis cryosections with a XY40-specific monoclonal antibody revealed that the labeling is confined to the axial elements of sex chromosomes. Biochemical characterization showed that protein XY40 (40 kDa; pI 5.7-5.8) can be extracted from rat pachytene spermatocytes and recovered in particles of 9.5 S with a native molecular mass of approximately 152 kDa. We speculate that protein XY40 may be involved in the allocyclic behavior of sex chromosomes during male meiotic prophase. Images

Smith, A; Benavente, R

1992-01-01

196

Method of detecting genetic translocations identified with chromosomal abnormalities  

DOEpatents

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 analyses. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acid probes are typically of a complexity greater than 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, particularly 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 but genetically different diseases, and for many prognostic and diagnostic applications.

Gray, Joe W. (Livermore, CA); Pinkel, Daniel (Walnut Creek, CA); Tkachuk, Douglas (Livermore, CA)

2001-01-01

197

Method of detecting genetic deletions identified with chromosomal abnormalities  

DOEpatents

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.

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

2013-11-26

198

Sex Chromosome-Specific Regulation in the Drosophila Male Germline But Little Evidence for Chromosomal Dosage Compensation or Meiotic Inactivation  

PubMed Central

The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW in females) has repeatedly elicited the evolution of two kinds of chromosome-specific regulation: dosage compensation—the equalization of X chromosome gene expression in males and females— and meiotic sex chromosome inactivation (MSCI)—the transcriptional silencing and heterochromatinization of the X during meiosis in the male (or Z in the female) germline. How the X chromosome is regulated in the Drosophila melanogaster male germline is unclear. Here we report three new findings concerning gene expression from the X in Drosophila testes. First, X chromosome-wide dosage compensation appears to be absent from most of the Drosophila male germline. Second, microarray analysis provides no evidence for X chromosome-specific inactivation during meiosis. Third, we confirm the previous discovery that the expression of transgene reporters driven by autosomal spermatogenesis-specific promoters is strongly reduced when inserted on the X chromosome versus the autosomes; but we show that this chromosomal difference in expression is established in premeiotic cells and persists in meiotic cells. The magnitude of the X-autosome difference in transgene expression cannot be explained by the absence of dosage compensation, suggesting that a previously unrecognized mechanism limits expression from the X during spermatogenesis in Drosophila. These findings help to resolve several previously conflicting reports and have implications for patterns of genome evolution and speciation in Drosophila.

Meiklejohn, Colin D.; Landeen, Emily L.; Cook, Jodi M.; Kingan, Sarah B.; Presgraves, Daven C.

2011-01-01

199

Cytogenetic analysis shows that the unusually large chromosome in the sex-limited pB silkworm (Bombyx mori) strain consists of three chromosomes.  

PubMed

We have discovered an inordinately large chromosome pair at the pachytene stage in the oocyte of the sex-limited pB (black larval marking) silkworm (Bombyx mori) strain (TWPB). We have analyzed the composition and arrangement of this large chromosome. A genetic linkage analysis shows that the large chromosome is made up of the W chromosome, the second chromosome fragment (pB fragment), and the fifth chromosome (linkage group) containing at least the region from map position 0.0 to 40.8. We also observed a sex heterochromatin body (SB) that we deduced to be made up of condensed W chromosomes. The number of SBs in each female nucleus among the sucking stomach cells of the TWPB strain was variable. Evidently, the W chromosome of the TWPB strain is attached to another chromosome. The composition of the W chromosome, the second chromosome fragment, and the fifth chromosome was studied through linkage analysis for these three chromosomes. We used two strains derived from the TWPB strain, the sex-limited pM (moricaud larval marking)-like (TWPML) and the autosomal pM-like (T5PML). The results show that the TWPML strain originates through a detachment of the fifth chromosome from the large chromosome of the TWPB strain, and the T5PML strain originates through a detachment of the W chromosome from that. Accordingly, the large chromosome of the TWPB strain is arranged in the order W chromosome--second chromosome fragment--fifth chromosome. PMID:11338434

Tanaka, N; Yokoyama, T; Abe, H; Tsuchida, K; Ninagi, O; Oshiki, T

2000-01-01

200

Limb malformations and abnormal sex hormone concentrations in frogs.  

PubMed Central

Declines in amphibian populations, and amphibians with gross malformations, have prompted concern regarding the biological status of many anuran species. A survey of bullfrogs, Rana catesbeiana, and green frogs, Rana clamitans, conducted in central and southern New Hampshire showed malformed frogs at 81% of the sites sampled (13 of 16 sites). Brain gonadotropin-releasing hormone (GnRH) and the synthesis of androgens and estradiol, hormones essential to reproductive processes, were measured from limb-malformed and normal (no limb malformation) frogs. Normal frogs had significantly higher concentrations (nearly 3-fold) of in vitro produced androgens and of brain GnRH than malformed frogs. Because most malformations are thought to occur during development, we propose that environmental factors or endocrine-disrupting chemicals that may cause developmental abnormalities also act during early development to ultimately cause abnormally reduced GnRH and androgen production in adult frogs. The consequences of reduced GnRH and androgens on anuran reproductive behavior and population dynamics are unknown but certainly may be profound and warrant further research.

Sower, S A; Reed, K L; Babbitt, K J

2000-01-01

201

Distinct chromosomal abnormality pattern in primary liver cancer of non-B, non-C patients  

Microsoft Academic Search

To discriminate among the chromosomal abnormalities associated with the etiology of hepatocellular carcinoma (HCC), we performed a comparative genomic hybridization (CGH) analysis on 34 HCCs resected on non-cirrhotic livers from patients serologically negative for both hepatitis B (HBV) and C (HCV) viruses. The results were compared to those of a previous analysis of 50 HCCs selected on the basis of

Agnès Marchio; Pascal Pineau; Mounira Meddeb; Benoît Terris; Pierre Tiollais; Alain Bernheim; Anne Dejean

2000-01-01

202

Overview of Epidemiology, Genetics, Birth Defects, and Chromosome Abnormalities Associated With CDH  

PubMed Central

Congenital diaphragmatic hernia (CDH) is a common and well-studied birth defect. The etiology of most cases remains unknown but increasing evidence points to genetic causation. The data supporting genetic etiologies which are detailed below include the association of CDH with recurring chromosome abnormalities, the existence of CDH-multiplex families, and the co-occurrence of CDH with additional congenital malformations.

Pober, Barbara R.

2010-01-01

203

Caenorhabditis elegans Histone Methyltransferase MET-2 Shields the Male X Chromosome from Checkpoint Machinery and Mediates Meiotic Sex Chromosome Inactivation  

PubMed Central

Meiosis is a specialized form of cellular division that results in the precise halving of the genome to produce gametes for sexual reproduction. Checkpoints function during meiosis to detect errors and subsequently to activate a signaling cascade that prevents the formation of aneuploid gametes. Indeed, asynapsis of a homologous chromosome pair elicits a checkpoint response that can in turn trigger germline apoptosis. In a heterogametic germ line, however, sex chromosomes proceed through meiosis with unsynapsed regions and are not recognized by checkpoint machinery. We conducted a directed RNAi screen in Caenorhabditis elegans to identify regulatory factors that prevent recognition of heteromorphic sex chromosomes as unpaired and uncovered a role for the SET domain histone H3 lysine 9 histone methyltransferase (HMTase) MET-2 and two additional HMTases in shielding the male X from checkpoint machinery. We found that MET-2 also mediates the transcriptional silencing program of meiotic sex chromosome inactivation (MSCI) but not meiotic silencing of unsynapsed chromatin (MSUC), suggesting that these processes are distinct. Further, MSCI and checkpoint shielding can be uncoupled, as double-strand breaks targeted to an unpaired, transcriptionally silenced extra-chromosomal array induce checkpoint activation in germ lines depleted for met-2. In summary, our data uncover a mechanism by which repressive chromatin architecture enables checkpoint proteins to distinguish between the partnerless male X chromosome and asynapsed chromosomes thereby shielding the lone X from inappropriate activation of an apoptotic program.

Checchi, Paula M.; Engebrecht, JoAnne

2011-01-01

204

Old but not (so) degenerated-slow evolution of largely homomorphic sex chromosomes in ratites.  

PubMed

Degeneration of the nonrecombining chromosome is a common feature of sex chromosome evolution, readily evident by the presence of a pair of largely heteromorphic chromosomes, like in eutherian mammals and birds. However, in ratites (order Palaeognathae, including, e.g., ostrich), the Z and W chromosomes are similar in size and largely undifferentiated, despite avian sex chromosome evolution was initiated > 130 Ma. To better understand what may limit sex chromosome evolution, we performed ostrich transcriptome sequencing and studied genes from the nonrecombining region of the W chromosome. Fourteen gametologous gene pairs present on the W chromosome and Z chromosome were identified, with synonymous sequence divergence of 0.027-0.177. The location of these genes on the Z chromosome was consistent with a sequential increase in divergence, starting 110-157 and ending 24-30 Ma. On the basis of the occurrence of Z-linked genes hemizygous in females, we estimate that about one-third of the Z chromosome does not recombine with the W chromosome in female meiosis. Pairwise dN/dS between gametologs decreased with age, suggesting strong evolutionary constraint in old gametologs. Lineage-specific dN/dS was consistently higher in W-linked genes, in accordance with the lower efficacy of selection expected in nonrecombining chromosomes. A higher ratio of GC > AT:AT > GC substitutions in W-linked genes supports a role for GC-biased gene conversion in differentially driving base composition on the two sex chromosomes. A male-to-female (M:F) expression ratio of close to one for recombining genes and close to two for Z-linked genes lacking a W copy show that dosage compensation is essentially absent. Some gametologous genes have retained active expression of the W copy in females (giving a M:F ratio of 1 for the gametologous gene pair), whereas for others W expression has become severely reduced resulting in a M:F ratio of close to 2. These observations resemble the patterns of sex chromosome evolution seen in other avian and mammalian lineages, suggesting similar underlying evolutionary processes, although the rate of sex chromosome differentiation has been atypically low. Lack of dosage compensation may be a factor hindering sex chromosome evolution in this lineage. PMID:24618361

Yazdi, Homa Papoli; Ellegren, Hans

2014-06-01

205

Contrasting patterns of X/Y polymorphism distinguish Carica papaya from other sex chromosome systems.  

PubMed

The sex chromosomes of the tropical crop papaya (Carica papaya) are evolutionarily young and consequently allow for the examination of evolutionary mechanisms that drive early sex chromosome divergence. We conducted a molecular population genetic analysis of four X/Y gene pairs from a collection of 45 wild papaya accessions. These population genetic analyses reveal striking differences in the patterns of polymorphism between the X and Y chromosomes that distinguish them from other sex chromosome systems. In most sex chromosome systems, the Y chromosome displays significantly reduced polymorphism levels, whereas the X chromosome maintains a level of polymorphism that is comparable to autosomal loci. However, the four papaya sex-linked loci that we examined display diversity patterns that are opposite this trend: the papaya X alleles exhibit significantly reduced polymorphism levels, whereas the papaya Y alleles maintain greater than expected levels of diversity. Our analyses suggest that selective sweeps in the regions of the X have contributed to this pattern while also revealing geographically restricted haplogroups on the Y. We discuss the possible role sexual selection and/or genomic conflict have played in shaping the contrasting patterns of polymorphism found for the papaya X and Y chromosomes. PMID:22855536

Weingartner, Laura A; Moore, Richard C

2012-12-01

206

Non-homologous sex chromosomes of birds and snakes share repetitive sequences.  

PubMed

Snake sex chromosomes provided Susumo Ohno with the material on which he based his theory of how sex chromosomes differentiate from autosomal pairs. Like birds, snakes have a ZZ male/ZW female sex chromosome system, in which the snake Z is a macrochromosome much the same size as the bird Z. However, the gene content shows clearly that the snake and bird Z chromosomes are completely non-homologous. The molecular aspect of W chromosome degeneration in snakes remains largely unexplored. We used comparative genomic hybridization to identify the female-specific region of the W chromosome in representative species of Australian snakes. Using this approach, we show that an increasingly complex suite of repeats accompanies the evolution of W chromosome heteromorphy. In particular, we found that while the python Liasis fuscus exhibits no sex-specific repeats and indeed, no cytologically recognizable sex-specific region, the colubrid Stegonotus cucullatus shows a large domain on the short arm of the W chromosome that consists of female-specific repeats, and the large W of Notechis scutatus is composed almost entirely of repetitive sequences, including Bkm and 18S rDNA-related elements. FISH mapping of both simple and complex probes shows patterns of repeat amplification concordant with the size of the female-specific region in each species examined. Mapping of intronic sequences of genes that are sex-linked in both birds (DMRT1) and snakes (CTNNB1) reveals massive amplification in discrete domains on the W chromosome of the elapid N. scutatus. Using chicken W chromosome paint, we demonstrate that repetitive sequences are shared between the sex chromosomes of birds and derived snakes. This could be explained by ancestral but as yet undetected shared synteny of bird and snake sex chromosomes or may indicate functional homology of the repeats and suggests that degeneration is a convergent property of sex chromosome evolution. We also establish that synteny of snake Z-linked genes has been conserved for at least 166 million years and that the snake Z consists of two conserved blocks derived from the same ancestral vertebrate chromosome. PMID:20734128

O'Meally, Denis; Patel, Hardip R; Stiglec, Rami; Sarre, Stephen D; Georges, Arthur; Marshall Graves, Jennifer A; Ezaz, Tariq

2010-11-01

207

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

Microsoft Academic Search

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

B. K. Hecht; M Chatel; J. Gioanni

1994-01-01

208

Somatic Chromosome Abnormalities in the Lungs of Patients with Pulmonary Arterial Hypertension  

PubMed Central

Rationale: Vascular remodeling in pulmonary arterial hypertension (PAH) involves proliferation and migration of endothelial and smooth muscle cells, leading to obliterative vascular lesions. Previous studies have indicated that the endothelial cell proliferation is quasineoplastic, with evidence of monoclonality and instability of short DNA microsatellite sequences. Objectives: To assess whether there is larger-scale genomic instability. Methods: We performed genome-wide microarray copy number analysis on pulmonary artery endothelial cells and smooth muscle cells isolated from the lungs of patients with PAH. Measurements and Main Results: Mosaic chromosomal abnormalities were detected in PAEC cultures from five of nine PAH lungs but not in normal (n = 8) or disease control subjects (n = 5). Fluorescent in situ hybridization analysis confirmed the presence of these abnormalities in vivo in two of three cases. One patient harbored a germline mutation of BMPR2, the primary genetic cause of PAH, and somatic loss of chromosome-13, which constitutes a second hit in the same pathway by deleting Smad-8. In two female subjects with mosaic loss of the X chromosome, methylation analysis showed that the active X was deleted. One subject also showed completely skewed X-inactivation in the nondeleted cells, suggesting the pulmonary artery endothelial cell population was clonal before the acquisition of the chromosome abnormality. Conclusions: Our data indicate a high frequency of genetically abnormal subclones within PAH lung vessels and provide the first definitive evidence of a second genetic hit in a patient with a germline BMPR2 mutation. We propose that these chromosome abnormalities may confer a growth advantage and thus contribute to the progression of PAH.

Aldred, Micheala A.; Comhair, Suzy A.; Varella-Garcia, Marileila; Asosingh, Kewal; Xu, Weiling; Noon, George P.; Thistlethwaite, Patricia A.; Tuder, Rubin M.; Erzurum, Serpil C.; Geraci, Mark W.; Coldren, Christopher D.

2010-01-01

209

Assessemnt of nasal bone in first trimester screening for chromosomal abnormalities in Khuzestan  

PubMed Central

Background: Fetal nasal bone assessment is a non-invasive procedure that helps provide even greater assurance to patients undergoing their first trimester risk assessment for aneuploidies. Absence or presence of this factor is different in some races. Objective: The study was aimed to evaluate nasal bone in the first trimester of pregnancy in the indigenous population of Khuzestan Province, and to monitor its value in the diagnosis of chromosomal abnormalities. Materials and Methods: This study was conducted on 2314 pregnant women between 17-43 years old who referred for first trimester screening for chromosomal abnormalities. Gestational age was between 11-13w + 6 days. Nuchal translucency (NT), fetal heart rate (FHR), crown rump length (CRL), and maternal age and maternal blood serum factors (Free HCG) and pregnancy-associated plasma protein-A (PAPP-A) and nasal bone were assessed. Finally the risk of trisomies was calculated. The statistical tests are based on the relationship between chromosomal abnormality and the presence or absence of the nasal bone. Results: In 114 cases we could not examine the nasal bone. Also, in 20 cases missed abortion happened without knowing the karyotype. 2173 cases were delivered normal baby, and in seven cases chromosomal abnormalities were diagnosed. Nasal bone was absent in all three cases with trisomy 21 and six of 2173 cases with normal phenotype (0.3%). With use of the Fisher exact test (p=0.0001), a significant correlation was found between the absence of the nasal bone and the risk of chromosomal abnormality. Conclusion: Inclusion of the nasal bone in first-trimester combined screening for aneuploidies achieves greater detection rate especially in Down syndrome.

Masihi, Sara; Barati, Mojgan; Mohamadjafari, Razieh; Hashemi, Marzieh

2014-01-01

210

Health-related quality of life experienced by children with chromosomal abnormalities and congenital heart defects.  

PubMed

Long-term outcomes are fundamental in advising parents about the potential future of their children with congenital heart disease (CHD). No published reports have described the health-related quality of life (HRQL) experienced by children with chromosomal abnormalities who had surgery in early infancy for CHD. A study was undertaken to assess HRQL among children with chromosomal abnormalities and CHD. The authors hypothesized that these children have a worse HRQL than healthy children or a cohort of children matched for CHD diagnosis. Infants with chromosomal abnormalities undergoing cardiac surgery for CHD at 6 weeks of age or younger at the Stollery Children's Hospital between July 2000 and June 2005 were included in the study. The HRQL of these infants was assessed using the Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales completed by their parents at a 4-year follow-up evaluation. The study compared the scores for 16 children with normative data. The children with chromosomal abnormalities and CHD had significantly lower mean total PedsQL (71.3 vs. 87.3; p < 0.0001), Psychosocial Summary (70.3 vs. 86.1; p < 0.0001), and Physical Summary (74.3 vs. 89.2; p = 0.0006) scores. Compared with the matched children, those with chromosomal abnormalities had a significantly lower median total PedsQL (75.0 vs. 84.6; p = 0.03), Physical Summary (79.5 vs. 96.9; p = 0.007), and School Functioning (68.5 vs. 83.0; p = 0.03) scores. A better understanding of the mechanisms and determinants of HRQL in these children has the potential to yield important implications for clinical practice including clarity for treatment decision making as well as determination of targeted supports and services to meet the needs of these children and their families differentially. PMID:24158648

Garcia Guerra, Gonzalo; Joffe, Ari R; Robertson, Charlene M T; Atallah, Joseph; Alton, Gwen; Sauve, Reg S; Dinu, Irina A; Ross, David B; Rebeyka, Ivan M

2014-03-01

211

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

PubMed

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 São 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

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

2012-12-01

212

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

PubMed Central

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 São 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.

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

2012-01-01

213

Robertsonian translocation in a sex reversal dog (XX, SRY negative) may indicate that the causative mutation for this intersexuality syndrome resides on canine chromosome 23 (CFA23).  

PubMed

A Bernese mountain dog was subjected for clinical evaluation due to the presence of ambiguous external genitalia (enlarged clitoris). Anatomical and histological studies revealed the presence of one testicle, one ovotestis and a uterus. This dog was classified as a female-to-male sex reversal, with 2 normal X chromosomes and a lack of the Y chromosome-linked genes SRY and ZFY. It is the first case of this syndrome in this breed. Apparently a Robertsonian translocation, rob(5;23), was also identified in this dog and it is again the first case of this type of chromosome abnormality in this breed, as well as the first case of co-occurrence of the sex reversal syndrome along with a centric fusion in the dog. Since on the canine chromosome 23 (CFA23) 3 genes (FOXL2,PISRT1 and CTNNB1) involved in the sex determination process are present, further cytogenetic FISH studies were carried out with the use of BAC probes specific for this chromosome. It was found that a pericentromeric fragment of CFA23 was deleted as a result of the centric fusion. We hypothesize that a cis regulatory sequence for the sex determination genes on CFA23 (e.g. proximally located CTNNB1) is present in the deleted fragment. Thus, a causative mutation responsible for this sex reversal syndrome may reside on CFA23. PMID:21430365

Switonski, M; Szczerbal, I; Nizanski, W; Kociucka, B; Bartz, M; Dzimira, S; Mikolajewska, N

2011-01-01

214

How did the platypus get its sex chromosome chain? A comparison of meiotic multiples and sex chromosomes in plants and animals  

Microsoft Academic Search

The duck-billed platypus is an extraordinary mammal. Its chromosome complement is no less extraordinary, for it includes a\\u000a system in which ten sex chromosomes form an extensive meiotic chain in males. Such meiotic multiples are unprecedented in\\u000a vertebrates but occur sporadically in plant and invertebrate species. In this paper, we review the evolution and formation\\u000a of meiotic multiples in plants

Frank Gruetzner; Terry Ashley; David M. Rowell; Jennifer A. Marshall Graves

2006-01-01

215

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

Microsoft Academic Search

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

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

1999-01-01

216

Neo-sex chromosome diversity in Neotropical melanopline grasshoppers (Melanoplinae, Acrididae)  

Microsoft Academic Search

We report the results of a study on the neo-sex chromosome systems of six Neotropical Melanoplinae species for contributing\\u000a to a better understanding of their origin and behaviour of these systems. Our analyses included detailed descriptions of the\\u000a structure and behaviour of the sex chromosome configurations in male and female meiosis of species belonging to the genera\\u000a Ronderosia, Dichromatos and

Elio R. D. Castillo; Claudio J. Bidau; Dardo A. Martí

2010-01-01

217

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

PubMed Central

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 into two unlinked sex-determining regions, forming independent gene clusters that then fused via chromosomal translocation. A transitional tripolar intermediate state then converted to a bipolar system via gene conversion or recombination between the linked and unlinked sex-determining regions. MAT was subsequently subjected to intra- and interallelic gene conversion and inversions that suppress recombination. These events resemble those that shaped mammalian sex chromosomes, illustrating convergent evolution in sex-determining structures in the animal and fungal kingdoms.

2004-01-01

218

Independent Origin of Sex Chromosomes in Two Species of the Genus Silene  

PubMed Central

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.

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

2008-01-01

219

Sexual differentiation in the developing mouse brain: contributions of sex chromosome genes  

PubMed Central

Neural sexual differentiation begins during embryogenesis and continues after birth for a variable amount of time depending on the species and brain region. Because gonadal hormones were the first factors identified in neural sexual differentiation, their role in this process has eclipsed investigation of other factors. Here, we use a mouse with a spontaneous translocation that produces four different unique sets of sex chromosomes. Each genotype has one normal X-chromosome, and a unique second sex chromosome, creating the following genotypes: XY*x, XX, XY*, XXY*. This Y* mouse line is used by several laboratories to study two human aneuploid conditions: Turner and Klinefelter syndromes. Since sex chromosome number affects behavior and brain morphology, we surveyed brain gene expression at embryonic days 11.5 and 18.5 to isolate X-chromosome dose effects in the developing brain as possible mechanistic changes underlying the phenotypes. We compared gene expression differences between gonadal males and females as well as individuals with one versus two X-chromosomes. We present data showing, in addition to genes reported to escape X-inactivation, a number of autosomal genes are differentially expressed between the sexes and in mice with different numbers of X-chromosomes. Based on our results, we can now identify the genes present in the region around the chromosomal break point that produces the Y* model. Our results also indicate an interaction between gonadal development and sex chromosome number that could further elucidate the role of sex chromosome genes and hormones in the sexual differentiation of behavior.

Wolstenholme, Jennifer T.; Rissman, Emilie F.; Bekiranov, Stefan

2012-01-01

220

Analysis of non-clonal chromosome abnormalities observed in hematologic malignancies among Southwest Oncology Group patients  

SciTech Connect

From 1987-1994, the Southwest Oncology Group Cytogenetics Committee reviewed 1571 studies in 590 adult patient cases with ALL, AML, CML or CLL. These were analyzed for the presence of clinically important non-clonal abnormalities (NCA). Abnormalities were defined as non-clonal if one metaphase had a structural abnormality or an extra chromosome. Chromosome loss was not analyzed due to the possibility of random loss. In 72 cases (12%) comprising 136 studies, at least one NCA was observed. In 21 of these cases (29%), NCAs consisted of obvious clonal evolution or instability, and thus were not included in the analysis. At least one structural NCA was observed in which the abnormality differed from the mainline in 36 (50%) patients. Seventeen of the 36 cases had a normal mode. Nineteen of the 36 patients had an abnormal or normal/abnormal mode. At least one numerical NCA was found in 15 cases (21%). Fifteen cases (21%) contained at least one marker chromosome. Several cases involved NCA in more than one of the above divisions. NCAs could be classified into several categories: (1){open_quotes}the clone to come{close_quotes}, (2) evolving clones which then disappeared, (3) NCAs with putative clinical importance that never became clonal, (4) NCAs during remission identical to the preceding clonal abnormality, (5) NCAs which indicated clonal evolution or instability. Examples include one metaphase with t(9;22) or del(20q) or inv(16) or +8 which either preceded or followed clonal findings of the same aberration. Such findings should be communicated to the clinician.

McConnell, T.S. [Univ. of New Mexico, Albuquerque, NM (United States); Dobin, S.M. [Oregon Health Sciences Univ., Portland, OR (United States)

1994-09-01

221

Chromosomal Disorders and Autism.  

ERIC Educational Resources Information Center

This paper reviews the literature on chromosomal aberrations in autism, especially possible gene markers. It notes that Chromosome 15 and numerical and structural abnormalities of the sex chromosomes have been most frequently reported as related to the genesis of autism. (Author/DB)

Gillberg, Christopher

1998-01-01

222

Comparative Genetic Mapping Points to Different Sex Chromosomes in Sibling Species of Wild Strawberry (Fragaria)  

PubMed Central

Separate sexes have evolved repeatedly from hermaphroditic ancestors in flowering plants, and thus select taxa can provide unparalleled insight into the evolutionary dynamics of sex chromosomes that are thought to be shared by plants and animals alike. Here we ask whether two octoploid sibling species of wild strawberry—one almost exclusively dioecious (males and females), Fragaria chiloensis, and one subdioecious (males, females, and hermaphrodites), F. virginiana—share the same sex-determining chromosome. We created a genetic map of the sex chromosome and its homeologs in F. chiloensis and assessed macrosynteny between it and published maps of the proto-sex chromosome of F. virginiana and the homeologous autosome of hermaphroditic diploid species. Segregation of male and female function in our F. chiloensis mapping population confirmed that linkage and dominance relations are similar to those in F. virginiana. However, identification of the molecular markers most tightly linked to the sex-determining locus in the two octoploid species shows that, in both, this region maps to homeologues of chromosome 6 in diploid congeners, but is located at opposite ends of their respective chromosomes.

Goldberg, Margot T.; Spigler, Rachel B.; Ashman, Tia-Lynn

2010-01-01

223

Additional chromosome abnormalities in patients with acute promyelocytic leukemia treated with all-trans retinoic acid and chemotherapy  

PubMed Central

Background Acute promyelocytic leukemia is a subtype of acute myeloid leukemia characterized by the t(15;17). The incidence and prognostic significance of additional chromosomal abnormalities in acute promyelocytic leukemia is still a controversial matter. Design and Methods Based on cytogenetic data available for 495 patients with acute promyelocytic leukemia enrolled in two consecutive PETHEMA trials (LPA96 and LPA99), we analyzed the incidence, characteristics, and outcome of patients with acute promyelocytic leukemia with and without additional chromosomal abnormalities who had been treated with all-trans retinoic acid plus anthracycline monochemotherapy for induction and consolidation. Results Additional chromosomal abnormalities were observed in 140 patients (28%). Trisomy 8 was the most frequent abnormality (36%), followed by abn(7q) (5%). Patients with additional chromosomal abnormalities more frequently had coagulopathy (P=0.03), lower platelet counts (P=0.02), and higher relapse-risk scores (P=0.02) than their counterparts without additional abnormalities. No significant association with FLT3/ITD or other clinicopathological characteristics was demonstrated. Patients with and without additional chromosomal abnormalities had similar complete remission rates (90% and 91%, respectively). Univariate analysis showed that additional chromosomal abnormalities were associated with a lower relapse-free survival in the LPA99 trial (P=0.04), but not in the LPA96 trial. However, neither additional chromosomal abnormalities overall nor any specific abnormality was identified as an independent risk factor for relapse in multivariate analysis. Conclusions The lack of independent prognostic value of additional chromosomal abnormalities in acute promyelocytic leukemia does not support the use of alternative therapeutic strategies when such abnormalities are found.

Cervera, Jose; Montesinos, Pau; Hernandez-Rivas, Jesus M.; Calasanz, Maria J.; Aventin, Anna; Ferro, Maria T.; Luno, Elisa; Sanchez, Javier; Vellenga, Edo; Rayon, Chelo; Milone, Gustavo; de la Serna, Javier; Rivas, Concha; Gonzalez, Jose D.; Tormo, Mar; Amutio, Elena; Gonzalez, Marcos; Brunet, Salut; Lowenberg, Bob; Sanz, Miguel A.

2010-01-01

224

Abnormalities of chromosomes 3 and 8 in posterior uveal melanoma correlate with prognosis.  

PubMed

Posterior uveal melanomas have nonrandom alterations affecting chromosomes 3, 6, and 8. Loss of chromosome 3 in uveal melanoma has been shown to act as a predictor of disease-free and overall survival. To confirm the significance of chromosome 3 loss and to extend the observations to include those of the associated alterations of chromosome 8, we have conducted a cytogenetic analysis on a series of 42 tumours from patients with primary uveal melanoma who were followed up for a median of 31 months (range = 8-96 months). Abnormalities of chromosomes 3 and 8 were the commonest changes and were confirmed in 10 tumours using fluorescence in situ hybridization. Monosomy of chromosome 3 was found in 21 (50%) of the tumours, and 23 (54%) tumours had additional copies of 8q. Alterations of chromosomes 3 and 8 were found occurring together in 19 (45%) of the tumours and were significantly associated with a ciliary body component (P < 0.0001). Prognostic indicators and changes of chromosomes 3 and 8 were analysed for correlation with patient survival. Of the chosen parameters, only ciliary body involvement (P = 0.003), monosomy of chromosome 3 (P = 0.0007), and additional copies of 8q (P = 0.003) correlated with reduced survival. Evaluation of the dosage effect of additional copies of chromosome arm 8q showed a significant association with reduced survival (P = 0.0001), which was also predictive of a decreased disease-free interval (P = 0.01). Thus, the cytogenetic analysis of uveal melanoma may provide a valuable predictor of prognosis. PMID:9135991

Sisley, K; Rennie, I G; Parsons, M A; Jacques, R; Hammond, D W; Bell, S M; Potter, A M; Rees, R C

1997-05-01

225

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

SciTech Connect

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.

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

226

Centrosomal abnormalities, multipolar mitoses, and chromosomal instability in head and neck tumours with dysfunctional telomeres  

PubMed Central

Carcinomas of the head and neck typically exhibit complex chromosome aberrations but the underlying mutational mechanisms remain obscure. Evaluation of cell division dynamics in low-passage cell lines from three benign and five malignant head and neck tumours revealed a strong positive correlation between multipolarity of the mitotic spindle and the formation of bridges at anaphase in both benign and malignant tumours. Cells exhibiting a high rate of mitotic abnormalities also showed several chromosome termini lacking TTAGGG repeats and a high frequency of dicentric chromosomes. Multicolour karyotyping demonstrated a preferential involvement in structural rearrangements of chromosomes with deficient telomeres. The majority of malignant, mitotically unstable tumours expressed the reverse transcriptase subunit of telomerase. These data indicate that some of the genomic instability in head and neck tumours is initiated by telomere dysfunction, leading to the formation of dicentric chromosomes. These form chromosome bridges at mitosis that could prevent the normal anaphase-telophase transition. In turn, this may cause an accumulation of centrosomes and mitotic multipolarity. Telomerase expression does not confer total stability to the tumour genome but could be crucial for moderating the rate of chromosomal evolution. British Journal of Cancer (2002) 37, 202–207. doi:10.1038/sj.bjc.6600438 www.bjcancer.com © 2002 Cancer Research UK

Gisselsson, D; Jonson, T; Yu, C; Martins, C; Mandahl, N; Wiegant, J; Jin, Y; Mertens, F; Jin, C

2002-01-01

227

The role of repetitive DNA in structure and evolution of sex chromosomes in plants.  

PubMed

Eukaryotic genomes contain a large proportion of repetitive DNA sequences, mostly transposable elements (TEs) and tandem repeats. These repetitive sequences often colonize specific chromosomal (Y or W chromosomes, B chromosomes) or subchromosomal (telomeres, centromeres) niches. Sex chromosomes, especially non-recombining regions of the Y chromosome, are subject to different evolutionary forces compared with autosomes. In non-recombining regions of the Y chromosome repetitive DNA sequences are accumulated, representing a dominant and early process forming the Y chromosome, probably before genes start to degenerate. Here we review the occurrence and role of repetitive DNA in Y chromosome evolution in various species with a focus on dioecious plants. We also discuss the potential link between recombination and transposition in shaping genomes. PMID:19277056

Kejnovsky, E; Hobza, R; Cermak, T; Kubat, Z; Vyskot, B

2009-06-01

228

Persistent Mosaicism for 12p Duplication/Triplication Chromosome Structural Abnormality in Peripheral Blood  

PubMed Central

We present a rare case of mosaicism for a structural abnormality of chromosome 12 in a patient with phenotypic features of Pallister-Killian syndrome. A six-month-old child with dysmorphic features, exotropia, hypotonia, and developmental delay was mosaic for both a normal karyotype and a cell line with 12p duplication/triplication in 25 percent of metaphase cells. Utilization of fluorescence in situ hybridization (FISH) identified three copies of probes from the end of the short arm of chromosome 12 (TEL(12p13) locus and the subtelomere (12p terminal)) on the structurally abnormal chromosome 12. Genome-wide SNP array analysis revealed that the regions of duplication and triplication were of maternal origin. The abnormal cell line in our patient was present at 25 percent at six months and 19 months of age in both metaphase and interphase cells from peripheral blood, where typically the isochromosome 12p is absent in the newborn. This may suggest that the gene(s) resulting in a growth disadvantage of abnormal cells in peripheral blood of patients with tetrasomy 12p may not have the same influence when present in only three copies.

Shackelford, Amy L.; Conlin, Laura K.; Spinner, Nancy B.; Wenger, Sharon L.

2013-01-01

229

The Number of X Chromosomes Causes Sex Differences in Adiposity in Mice  

Microsoft Academic Search

Sexual dimorphism in body weight, fat distribution, and metabolic disease has been attributed largely to differential effects of male and female gonadal hormones. Here, we report that the number of X chromosomes within cells also contributes to these sex differences. We employed a unique mouse model, known as the “four core genotypes,” to distinguish between effects of gonadal sex (testes

Xuqi Chen; Rebecca McClusky; Jenny Chen; Simon W. Beaven; Peter Tontonoz; Arthur P. Arnold; Karen Reue

2012-01-01

230

Molecular differentiation of the homomorphic sex chromosomes in Megaselia scalaris (Diptera) detected by random DNA probes  

Microsoft Academic Search

Randomly cloned DNA fragments and a poly-(GATA) containing sequence were used as probes to identify sex chromosomal inheritance and to detect differences at the molecular level between the homomorphic X and Y in the phorid fly,Megaselia scalaris. Restriction fragment length differences between males and females and between two laboratory stocks of different geographic origin were used to differentiate between sex

Ute Willhoeft; Walther Traut

1990-01-01

231

Brain Organization in a Reptile Lacking Sex Chromosomes: Effects of Gonadectomy and Exogenous Testosterone  

Microsoft Academic Search

In mammals, males and females differ both genetically and hormonally, making it difficult to assess the relative contributions of genetic constitution and fetal environment in the process of sexual differentiation. Many reptiles lack sex chromosomes, relying instead on the temperature of incubation to determine sex. In the leopard gecko (Eublepharis macularius), an incubation temperature of 26°C produces all females, whereas

David Crews; Patricia Coomber; Ryan Baldwin; Nilofer Azad; Francisco Gonzalez-Lima

1996-01-01

232

Chromosomal evolution in bovids: a comparison of cattle, sheep and goat G- and R-banded chromosomes and cytogenetic divergences among cattle, goat and river buffalo sex chromosomes.  

PubMed

A G- and R-banding comparison of cattle (Bos taurus, 2n = 60), goat (Capra hircus, 2n = 60) and sheep (Ovis aries, 2n = 54) chromosomes at the 450 band level was made. The study revealed a large number of banding homologies among the autosomes of the three species and resolved some ambiguities in arranging some of their small disputed acrocentrics by direct and indirect comparisons with some bovid marker chromosomes. A loss of the subcentromeric G-positive band in sheep chromosome 2g was observed when the G-banding patterns of sheep 2q and homologous cattle and goat chromosome 2 were compared. The chromosomal divergences among cattle, goat and river buffalo (Bubalus bubalis, 2n = 50) sex chromosomes are shown to have occurred by pericentric and paracentric inversions with a loss (or acquisition of constitutive heterochromatin. PMID:7551543

Iannuzzi, L; Di Meo, G P

1995-08-01

233

CAFE: an R package for the detection of gross chromosomal abnormalities from gene expression microarray data  

PubMed Central

Summary: The current methods available to detect chromosomal abnormalities from DNA microarray expression data are cumbersome and inflexible. CAFE has been developed to alleviate these issues. It is implemented as an R package that analyzes Affymetrix *.CEL files and comes with flexible plotting functions, easing visualization of chromosomal abnormalities. Availability and implementation: CAFE is available from https://bitbucket.org/cob87icW6z/cafe/ as both source and compiled packages for Linux and Windows. It is released under the GPL version 3 license. CAFE will also be freely available from Bioconductor. Contact: sander.h.bollen@gmail.com or nancy.mah@mdc-berlin.de Supplementary information: Supplementary data are available at Bioinformatics online.

Bollen, Sander; Mah, Nancy

2014-01-01

234

Solar activity cycle and the incidence of foetal chromosome abnormalities detected at prenatal diagnosis  

NASA Astrophysics Data System (ADS)

We studied 2001 foetuses during the period of minimal solar activity of solar cycle 21 and 2265 foetuses during the period of maximal solar activity of solar cycle 22, in all women aged 37 years and over who underwent free prenatal diagnosis in four hospitals in the greater Tel Aviv area. There were no significant differences in the total incidence of chromosomal abnormalities or of trisomy between the two periods (2.15% and 1.8% versus 2.34% and 2.12%, respectively). However, the trend of excessive incidence of chromosomal abnormalities in the period of maximal solar activity suggests that a prospective study in a large population would be required to rule out any possible effect of extreme solar activity.

Halpern, Gabrielle J.; Stoupel, Eliahu G.; Barkai, Gad; Chaki, Rina; Legum, Cyril; Fejgin, Moshe D.; Shohat, Mordechai

1995-06-01

235

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

PubMed Central

Sex chromosome inactivation in male germ cells is a paradigm of epigenetic programming during sexual reproduction. Recent progress has revealed the underlying mechanisms of sex chromosome inactivation in male meiosis. The trigger of chromosome-wide silencing is activation of the DNA damage response (DDR) pathway, which is centered on the mediator of DNA damage checkpoint 1 (MDC1), a binding partner of phosphorylated histone H2AX (?H2AX). This DDR pathway shares features with the somatic DDR pathway recognizing DNA replication stress in the S phase. Additionally, it is likely to be distinct from the DDR pathway that recognizes meiosis-specific double-strand breaks. This review article extensively discusses the underlying mechanism of sex chromosome inactivation.

Ichijima, Yosuke; Sin, Ho-Su

2013-01-01

236

A sex-chromosome mutation in Silene latifolia  

Microsoft Academic Search

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

Paige M. MillerRichard; Richard V. Kesseli

237

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

PubMed Central

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.

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

2014-01-01

238

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

PubMed

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

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

2014-01-01

239

Maternal Serum Placental Protein 13 at Eleven to Thirteen Weeks in Chromosomally Abnormal Pregnancies  

Microsoft Academic Search

Objective: To investigate whether the maternal serum concentration of placental protein 13 (PP13) is altered in chromosomally abnormal pregnancies and to examine the potential value of this placental protein in screening for aneuploidies at 11–13 weeks. Methods: The maternal serum concentration of PP13 at 11–13 weeks was compared in 536 euploid and 134 aneuploid pregnancies (trisomy 21: n = 49;

Ranjit Akolekar; José María Pérez Penco; Evdoxia Skyfta; Jesús Rodríguez Calvo; Kypros H. Nicolaides

2010-01-01

240

Chromosomal abnormalities & oxidative stress in women with premature ovarian failure (POF)  

PubMed Central

Background & objectives: Premature ovarian failure (POF) is defined as the cessation of ovarian function under the age of 40 yr and is characterized by amenorrhoea, hypoestrogenism and elevated serum gonadotrophin levels. The cause of POF remains undetermined in majority of the cases. This study was aimed to investigate the type and frequency of cytogenetic abnormalities in patients with idiopathic POF and also to study the role of oxidative stress in such cases. Methods: Seventy five women with idiopathic POF were included in this study. Chromosome analysis was done in peripheral blood lymphocytes by conventional GTG banding to identify numerical or structural abnormalities. Cytogenetically normal cases were investigated for reactive oxygen species (ROS) levels in their blood by luminol-chemiluminescence assay. Results: Eighteen chromosomal anomalies were identified in POF patients (24%). Majority of the cases were found to have X-chromosome abnormalities (28%). Overall median ROS range was found to be significantly higher (P<0.01) in POF patients [50480 (120,132966) RLU/min] compared to controls [340 (120,5094) RLU/min]. Among these, 50 per cent of the POF patients had higher ROS levels, 20 per cent had medium elevation and 30 per cent were found to have normal values comparable to controls. Interpretation & conclusions: X-chromosome anomalies were found to be the major contributor of POF. Oxidative stress may be the underlying aetiology in idiopathic premature ovarian failure. Thus the results of this study highlight the role of cytogenetic abnormalities and supraphysiological levels of ROS in causation of idiopathic POF. But the role of oxidative stress needs to be confirmed by other studies on patients from different geographical areas and from different ethnicities.

Kumar, Manoj; Pathak, Dhananjay; Venkatesh, Sundararajan; Kriplani, Alka; Ammini, A.C.; Dada, Rima

2012-01-01

241

A New Neurological Syndrome with Mental Retardation, Choreoathetosis, and Abnormal Behavior Maps to Chromosome Xp11  

PubMed Central

Summary Choreoathetosis is a major clinical feature in only a small number of hereditary neurological disorders. We define a new X-linked syndrome with a unique clinical picture characterized by mild mental retardation, choreoathetosis, and abnormal behavior. We mapped the disease in a four-generation pedigree to chromosome Xp11 by linkage analysis and defined a candidate region containing a number of genes possibly involved in neuronal signaling, including a potassium channel gene and a neuronal G protein–coupled receptor.

Reyniers, Edwin; Van Bogaert, Patrick; Peeters, Nils; Vits, Lieve; Pauly, Fernand; Fransen, Erik; Van Regemorter, Nicole; Kooy, R. Frank

1999-01-01

242

Cytogenetics of the genus Leporinus (Pisces, Anostomidae). 1. Karyotype analysis, heterochromatin distribution and sex chromosomes.  

PubMed

Cytogenetic analyses (Giemsa staining, C-banding, AgNO3 labelling of nucleolus organizer regions (NORs) and staining with base-specific fluorochromes) were performed on the South American fish species Leporinus friderici, L. obtusidens and L. elongatus. The overall karyotypic structure, position of NORs, as well as the amount, distribution and composition of constitutive heterochromatin were determined. Particular attention was given to the highly differentiated ZZ/ZW sex chromosome system of L. obtusidens and L. elongatus. Sharing the apparently ancient macroscopic karyotype of Anostomidae, all three species have 2n = 54 meta- or submetacentric chromosomes. NORs were found exclusively on chromosome pair 2, which may represent the ancestral NOR-bearing chromosome of the anostomid karyotype. Observed differences in the relative position of NORs along chromosome 2 and variations in the amount and distribution of constitutive heterochromatin throughout the karyotype were most probably caused by heterochromatin-mediated chromosome rearrangements. Detailed analysis of the morphologically similar heteromorphic ZZ/ZW sex chromosomes of L. obtusidens and L. elongatus allowed detection of differences in the DNA composition of the largely heterochromatic W chromosomes. However, since these and the W chromosomes of three other Leporinus species exhibit homologies with respect to their relative size, centromere position and amount and distribution of heterochromatin, it is concluded that they evolved from the same ancestral W chromosome. PMID:9088639

Koehler, M R; Dehm, D; Guttenbach, M; Nanda, I; Haaf, T; Molina, W F; Galetti, P M; Schmid, M

1997-02-01

243

Dosage Compensation Regulatory Proteins and the Evolution of Sex Chromosomes in Drosophila  

PubMed Central

In the fruitfly Drosophila melanogaster, the four male-specific lethal (msl) genes are required to achieve dosage compensation of the male X chromosome. The MSL proteins are thought to interact with cis-acting sites that confer dosage compensation to nearby genes, as they are detected at hundreds of discrete sites along the length of the polytene X chromosome in males but not in females. The histone H4 acetylated isoform, H4Ac16, colocalizes with the MSL proteins at a majority of sites on the D. melanogaster X chromosome. Using polytene chromosome immunostaining of other species from the genus Drosophila, we found that X chromosome association of MSL proteins and H4Ac16 is conserved despite differences in the sex chromosome karyotype between species. Our results support a model in which cis-acting regulatory sites for dosage compensation evolve on a neo-X chromosome arm in response to the degeneration of its former homologue.

Bone, J. R.; Kuroda, M. I.

1996-01-01

244

Incidence of chromosome aberrations among 11 148 newborn children  

Microsoft Academic Search

Chromosome analysis has been made of 11 148 children; 29 had sex chromosome abnormalities (2.60 per 1000) and 64 autosomal abnormalities (5.74 per 1000). The total incidence of major chromosome abnormalities was 8.34 per 1000.

Johannes Nielsen; Ingelise Sillesen

1975-01-01

245

Radiation exposure and chromosome abnormalities. Human cytogenetic studies at the National Institute of Radiological Sciences, Japan, 1963-1988.  

PubMed

The results of human cytogenetic studies performed at the National Institute of Radiological Sciences (NIRS), Chiba, Japan for about 25 years are described. The studies were pursued primarily under two major projects: one involving people exposed to radiation under various conditions and the other involving patients with malignant diseases, especially leukemias. Whereas chromosome abnormalities in radiation-exposed people are excellent indicators of radiation exposure, their behavior in bone marrow provide useful information for a better understanding of chromosome abnormalities in leukemias and related disorders. The role of chromosome abnormalities in the genesis and development of leukemia and related disorders is considered, suggesting a view for future studies in this field. PMID:2302680

Ishihara, T; Kohno, S; Minamihisamatsu, M

1990-03-01

246

Radiation exposure and chromosome abnormalities. Human cytogenetic studies at the National Institute of Radiological Sciences, Japan, 1963-1988  

SciTech Connect

The results of human cytogenetic studies performed at the National Institute of Radiological Sciences (NIRS), Chiba, Japan for about 25 years are described. The studies were pursued primarily under two major projects: one involving people exposed to radiation under various conditions and the other involving patients with malignant diseases, especially leukemias. Whereas chromosome abnormalities in radiation-exposed people are excellent indicators of radiation exposure, their behavior in bone marrow provide useful information for a better understanding of chromosome abnormalities in leukemias and related disorders. The role of chromosome abnormalities in the genesis and development of leukemia and related disorders is considered, suggesting a view for future studies in this field.

Ishihara, T.; Kohno, S.; Minamihisamatsu, M. (National Institute of Radiological Sciences, Chiba (Japan))

1990-03-01

247

A contribution to the differential diagnosis of the "group of schizophrenias": structural abnormality of chromosome 4.  

PubMed Central

A structural abnormality of chromosome 4 [inv 4 (p15.2; q21.3)] is reported in a male presenting with DSM-III-R schizophrenia, undifferentiated type (295.94) and in his mother, who displayed symptoms associated with schizotypal personality disorder (DSM-III-R 301.22). The proband had a performance IQ of 91, poor motor coordination, stature in the lowest quartile and an impaired sense of time. There were no diagnostic physical or neurological abnormalities. Mild ventricular enlargement and prominent sulci were found on computed tomography. Both he and his chromosomally normal father had strabismus which required surgical correction. This case joins the long list of chromosomal abnormalities previously reported to confer an increased risk of mental illness and emphasizes the importance of a sophisticated differential diagnosis in evaluating patients who present with symptoms of schizophrenia. The implications for recent initiatives which attempt to localize genes conferring susceptibility to schizophrenia and other major mental illnesses are discussed. Images Fig. 2

Palmour, R M; Miller, S; Fielding, A; Vekemans, M; Ervin, F R

1994-01-01

248

Sequential gene targeting to make chimeric tumor models with de novo chromosomal abnormalities.  

PubMed

The discovery of chromosomal translocations in leukemia/lymphoma and sarcomas presaged a widespread discovery in epithelial tumors. With the advent of new-generation whole-genome sequencing, many consistent chromosomal abnormalities have been described together with putative driver and passenger mutations. The multiple genetic changes required in mouse models to assess the interrelationship of abnormalities and other mutations are severe limitations. Here, we show that sequential gene targeting of embryonic stem cells can be used to yield progenitor cells to generate chimeric offspring carrying all the genetic changes needed for cell-specific cancer. Illustrating the technology, we show that MLL-ENL fusion is sufficient for lethal leukocytosis and proof of genome integrity comes from germline transmission of the sequentially targeted alleles. This accelerated technology leads to a reduction in mouse numbers (contributing significantly to the 3Rs), allows fluorescence tagging of cancer-initiating cells, and provides a flexible platform for interrogating the interaction of chromosomal abnormalities with mutations. PMID:24419086

Chambers, Jennifer S; Tanaka, Tomoyuki; Brend, Tim; Ali, Hanif; Geisler, Nicola J; Khazin, Leah; Cigudosa, Juan C; Dear, T Neil; MacLennan, Kenneth; Rabbitts, Terence H

2014-03-01

249

Placental C4d as a common feature of chromosomally normal and abnormal miscarriages.  

PubMed

Placental C4d deposition is a feature of classical complement pathway activation and has been documented in various obstetrical settings. However, it is unknown whether placental C4d deposition is present in miscarriages and its frequency is different between chromosomally normal and abnormal miscarriages. This study was conducted to assess villous C4d deposition in miscarriages and to determine whether its frequency is different between chromosomally normal and abnormal miscarriages. Tissue samples (N?=?58) of elective abortions (n?=?20), miscarriages with normal chromosomes (n?=?15), trisomy 16 (n?=?13), and trisomy 22 (n?=?10) were analyzed. Immunohistochemical staining for C4d and CD138 was done. Placental C4d deposition was defined as linear C4d immunoreactivity along the syncytiotrophoblast. Placental C4d immunoreactivity was detected in 73.3 % (11/15) and 56.5 % (13/23) of miscarriages with normal chromosomes and trisomy cases, respectively, while it was found in 5 % (1/20) of elective abortions (p?chromosomes and trisomy cases, respectively, but not in elective abortions (p?=?0.07 and 0.01, for each). The frequencies of C4d deposition (46.2 vs. 70.0 %) and chronic deciduitis (38.5 vs. 20.0 %) were not also different between trisomy 16 and trisomy 22 cases. Placental C4d deposition is a prominent feature of miscarriages regardless of their chromosomal status. The overall findings suggest that complement-mediated placental injury is a common pathology of miscarriage with diagnostic values in routine pathology practice. PMID:24671647

Lee, Joong Yeup; Hong, Joon-Seok; Kim, Eun Na; Ahn, Soyeon; Choe, Jin; Hwang, Doyeong; Kim, Ki Chul; Kim, Seok Hyun; Kim, Chong Jai

2014-05-01

250

Genomic imprinting as a probable explanation for variable intrafamilial phenotypic expression of an unusual chromosome 3 abnormality  

SciTech Connect

We present a 4 generation family in which an abnormal chromosome 3 with dup(3)(q25) segregated from great-grandmother to grandmother to son without phenotypic effect. The son`s 2 daughters have dysmorphic features, mild developmental delays and congenital heart disease. Both girls have the abnormal chr. 3 but are the only family members with the abnormality to have phenotypic effects. An unaffected son of the father has normal chromosomes. FISH with whole chromosome paints for chromosomes 1, 2, 6, 7, 8, 14, 18, and 22 excluded these as the origin of the extra material. Chromosome 3-specific paint revealed a uniform pattern, suggesting that the extra material is from chromosome 3. Comparative genomic hybridization and DNA studies are pending. Possible explanations for the discordance in phenotypes between the 4th generation offspring and the first 3 generations include: an undetected rearrangement in the previous generations that is unbalanced in the two affected individuals; the chromosome abnormality may be a benign variant and unrelated to the phenotype; or, most likely, genomic imprinting. Genomic imprinting is suggested by the observation that a phenotypic effect was only seen after the chromosome was inherited from the father. The mothers in the first two generations appear to have passed the abnormal chr. 3 on without effect. This is an opportunity to delineate a region of the human genome affected by paternal imprinting.

Fryburg, J.S.; Shashi, V.; Kelly, T.E. [Univ. of Virginia Health Science Center, Charlottesville, VA (United States)] [and others

1994-09-01

251

Possible causes of chromosome instability: comparison of chromosomal abnormalities in cancer cell lines with mutations in BRCA1, BRCA2, CHK2 and BUB1.  

PubMed

A large proportion of epithelial cancers show the chromosome-instability phenotype, in which they have many chromosome abnormalities. This is thought to be the result of mutations that disrupt chromosome maintenance, but the causative mutations are not known. We identified cell lines known to have mutations that might cause chromosome instability, and examined their karyotypes. Two cell lines, the breast cancer line HCC1937 and the pancreatic cancer line CAPAN-1, that have mutations respectively in BRCA1 and BRCA2, had very abnormal karyotypes, with many structural and numerical chromosome changes and substantial variation between metaphases. However, two colorectal cancer lines with mutations in BUB1, a spindle checkpoint protein involved in chromosome segregation, had rather simple near-tetraploid karyotypes, with minimal loss or gain of chromosomes other than the endoreduplication event, and minimal structural change. Apart from tetraploidy, these karyotypes were typical of colorectal lines considered to be chromosomally stable. Two lines derived from the same tumour, DLD-1 and HCT-15, with bi-allelic mutation of CHK2, had karyotypes that were typical of near-diploid colorectal lines considered chromosomally stable. The karyotypes observed supported the proposed role for BRCA1 and BRCA2 mutations in chromosomal instability, but showed that the tested mutations in BUB1 and CHK2 did not result in karyotypes that would have been predicted if they were sufficient for chromosomal instability. PMID:15162061

Grigorova, M; Staines, J M; Ozdag, H; Caldas, C; Edwards, P A W

2004-01-01

252

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

PubMed Central

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 chromosomes. Here I demonstrate that four genes that are X-linked in S. latifolia are also linked in nondioecious S. vulgaris, which is consistent with Ohno's (1967) hypothesis that sex chromosomes evolve from a single pair of autosomes. I also report a genetic map for four S. latifolia X-linked genes, SlX1, DD44X, SlX4, and a new X-linked gene SlssX, which encodes spermidine synthase. The order of the genes on the S. latifolia X chromosome and divergence between the homologous X- and Y-linked copies of these genes supports the “evolutionary strata” model, with at least three consecutive expansions of the nonrecombining region on the Y chromosome (NRY) in this plant species.

Filatov, Dmitry A.

2005-01-01

253

Chromatin structural changes around satellite repeats on the female sex chromosome in Schistosoma mansoni and their possible role in sex chromosome emergence  

PubMed Central

Background In the leuphotrochozoan parasitic platyhelminth Schistosoma mansoni, male individuals are homogametic (ZZ) whereas females are heterogametic (ZW). To elucidate the mechanisms that led to the emergence of sex chromosomes, we compared the genomic sequence and the chromatin structure of male and female individuals. As for many eukaryotes, the lower estimate for the repeat content is 40%, with an unknown proportion of domesticated repeats. We used massive sequencing to de novo assemble all repeats, and identify unambiguously Z-specific, W-specific and pseudoautosomal regions of the S. mansoni sex chromosomes. Results We show that 70 to 90% of S. mansoni W and Z are pseudoautosomal. No female-specific gene could be identified. Instead, the W-specific region is composed almost entirely of 36 satellite repeat families, of which 33 were previously unknown. Transcription and chromatin status of female-specific repeats are stage-specific: for those repeats that are transcribed, transcription is restricted to the larval stages lacking sexual dimorphism. In contrast, in the sexually dimorphic adult stage of the life cycle, no transcription occurs. In addition, the euchromatic character of histone modifications around the W-specific repeats decreases during the life cycle. Recombination repression occurs in this region even if homologous sequences are present on both the Z and W chromosomes. Conclusion Our study provides for the first time evidence for the hypothesis that, at least in organisms with a ZW type of sex chromosomes, repeat-induced chromatin structure changes could indeed be the initial event in sex chromosome emergence.

2012-01-01

254

47,XXY males: sex chromosomes and tooth size.  

PubMed

Permanent tooth crowns of 47,XXY males were found to be generally larger than those of control males and females and their first-degree male and female relatives. These results suggest that tooth-size increase in 47,XXY males is due to a direct genetic effect and support the concept of the presence of a specific growth gene (or genes) in the human X and Y chromosomes. The effect of this gene (or genes) seems to be the promotion of tooth growth, and the Y chromosome is more effective than the X chromosome in this respect. PMID:7446531

Alvesalo, L; Portin, P

1980-11-01

255

Sex chromosome loss may represent a disease-associated clonal population in chronic lymphocytic leukemia.  

PubMed

Whether sex chromosome loss (SCL) is an age-related phenomenon or a cytogenetic marker of hematological disease is unclear. To address this issue in chronic lymphocytic leukemia (CLL), we investigated 20 cases with X or Y chromosome loss detected by conventional cytogenetics (CC). The frequency of SCL was low in CLL (2.3%). It was the sole abnormality, as detected by CC, in 10/20 (50%) patients. Fluorescence in situ hybridization (FISH) analyses confirmed SCL in all patients tested, present in 5-88% of cells (median: 68%). Deletions of 13q were observed by FISH in 16/20 (80%) patients. Compared with CLL without SCL, SCL was significantly associated with 13q deletion, especially when bi-allelic (P = 0.04). Co-hybridization analyses showed that SCL could be a concomitant, primary or secondary change, or be present in an independent clone. FISH analyses were performed on blood sub-populations isolated by Ficoll or flow cytometry. Comparing mononuclear cells (including CLL cells) and polynuclear cells separated by Ficoll, a maximum of 2% of polynuclear cells were found with SCL, whereas mononuclear cells exhibited a significantly higher loss frequency (range: 6-87%) (P = 0.03). Comparing B-cells (including CLL cells) and T-cells sorted by flow cytometry, the proportion of B-CD19+ cells with SCL was significantly higher (range: 88-96%) than that observed in T-CD3+ cells (range: 2-6%) (P = 0.008). We conclude that SCL has to be considered as a clonal aberration in CLL that may participate in the oncogenic process. PMID:24424752

Chapiro, Elise; Antony-Debre, Ileana; Marchay, Nathalie; Parizot, Christophe; Lesty, Claude; Cung, Hong-Anh; Mathis, Stephanie; Grelier, Aurore; Maloum, Karim; Choquet, Sylvain; Azgui, Zahia; Uzunov, Madalina; Leblond, Veronique; Merle-Beral, Helene; Sutton, Laurent; Davi, Frederic; Nguyen-Khac, Florence

2014-03-01

256

High-Resolution Identification of Chromosomal Abnormalities Using Oligonucleotide Arrays Containing 116,204 SNPs  

PubMed Central

Mutation of the human genome ranges from single base-pair changes to whole-chromosome aneuploidy. Karyotyping, fluorescence in situ hybridization, and comparative genome hybridization are currently used to detect chromosome abnormalities of clinical significance. These methods, although powerful, suffer from limitations in speed, ease of use, and resolution, and they do not detect copy-neutral chromosomal aberrations—for example, uniparental disomy (UPD). We have developed a high-throughput approach for assessment of DNA copy-number changes, through use of high-density synthetic oligonucleotide arrays containing 116,204 single-nucleotide polymorphisms, spaced at an average distance of 23.6 kb across the genome. Using this approach, we analyzed samples that failed conventional karyotypic analysis, and we detected amplifications and deletions across a wide range of sizes (1.3–145.9 Mb), identified chromosomes containing anonymous chromatin, and used genotype data to determine the molecular origin of two cases of UPD. Furthermore, our data provided independent confirmation for a case that had been misinterpreted by karyotype analysis. The high resolution of our approach provides more-precise breakpoint mapping, which allows subtle phenotypic heterogeneity to be distinguished at a molecular level. The accurate genotype information provided on these arrays enables the identification of copy-neutral loss-of-heterozygosity events, and the minimal requirement of DNA (250 ng per array) allows rapid analysis of samples without the need for cell culture. This technology overcomes many limitations currently encountered in routine clinical diagnostic laboratories tasked with accurate and rapid diagnosis of chromosomal abnormalities.

Slater, Howard R.; Bailey, Dione K.; Ren, Hua; Cao, Manqiu; Bell, Katrina; Nasioulas, Steven; Henke, Robert; Choo, K. H. Andy; Kennedy, Giulia C.

2005-01-01

257

47,XXX females, sex chromosomes, and tooth crown structure.  

PubMed

Enamel thickness of the maxillary permanent central incisors and canines in seven Finnish 47,XXX females, their first-degree male and female relatives, and control males and females from the general population were determined from radiographs. The results showed that enamel in teeth of 47,XXX females was clearly thicker than that of normal controls. On the other hand, the thickness of "dentin" (distance between mesial and distal dentinoenamel junctions) in 47,XXX females' teeth was about the same as that in normal control females, but clearly reduced as compared with that in control males. It is therefore obvious that in the triple-X chromosome complement the extra X chromosome is active in amelogenesis, whereas it has practically no influence on the growth of dentin. The calculations based on present and previous results in 45,X females and 47,XYY males indicate that the X chromosome increases metric enamel growth somewhat more effectively than the Y chromosome. Possibly, halfway states exist between active and repressed enamel genes on the X chromosome. The Y chromosome seems to promote dental growth in a holistic fashion. PMID:3692479

Alvesalo, L; Tammisalo, E; Therman, E

1987-12-01

258

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

PubMed

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 of S. cynthia neo-sex chromosomes. FISH mapping revealed that the Z chromosome and chromosome 12 of B. mori correspond to the Z chromosome and an autosome (A?) of S. c. ricini (Vietnam population, 2n=27, Z0 in female moths), respectively. B. mori chromosome 11 corresponds partly to another autosome (A?) and partly to a chromosome carrying nucleolar organizer region (NOR) of this subspecies. The NOR chromosome of S. c. ricini is also partly homologous to B. mori chromosome 24. Furthermore, our results revealed that two A? homologues each fused with the W and Z chromosomes in a common ancestor of both Japanese subspecies S. c. walkeri (Sapporo population, 2n=26, neo-Wneo-Z) and S. cynthia subsp. indet. (Nagano population, 2n=25, neo-WZ?Z?). One homologue, corresponding to the A? autosome in S. c. ricini and S. c. walkeri, fused with the W chromosome in S. cynthia subsp. indet. Consequently, the other homologue became a Z? chromosome. These results clearly showed a step-by-step evolution of the neo-sex chromosomes by repeated autosome-sex chromosome fusions. We suggest that the rearrangements of sex chromosomes may facilitate divergence of S. cynthia subspecies towards speciation. PMID:20668432

Yoshido, A; Sahara, K; Marec, F; Matsuda, Y

2011-04-01

259

The origin of an unusual sex chromosome constitution in Acomys sp. (Rodentia, Muridae) from Tanzania.  

PubMed

This paper describes a case which presents an evident variation from the "standard" XX/XY sex chromosomal constitution in a rodent, Acomys sp. This species known to be found in three localities of East Africa has only recently been separated from A. spinosissimus, its closest relative. In our study, five specimens of Acomys sp. and eight specimens of A. spinosissimus were live-trapped in five localities. Comparisons between the two taxa assed by G-banding show a complete homology in the chromosomal shape and banding pattern for 29 pairs of chromosomes corresponding to the complete autosomal set of A. spinosissimus. However, while all the A. spinosissimus analysed have 2n = 60 and a XY-XX system, in Acomys sp. males and females constitute mosaics for sex chromosomes in the bone marrow cells. Females (2n = 59, 60) have an excess (97%) of aneuploid cells with one single giant X chromosome, and males (2n = 60, 61) show X0/XY cells occurring in somatic tissues and XY cells in the germinal lineage. In addition, an odd heterochromatic submetacentric chromosome was identified in all the cells examined in two males and a female of Acomys sp. Since this chromosome was not related to sex determination and it is not present in all the analysed specimens, it can be considered as a B chromosome. Finally, the in situ fluorescence hybridisation (FISH) with telomeric probes showed a very intense interstitial telomeric signal (ITS) at the medial part on the long heterochromatic arm of the X chromosome. This could be due to recent chromosomal rearrangement. PMID:17180438

Castiglia, Riccardo; Makundi, Rhodes; Corti, Marco

2007-10-01

260

46,XX sex reversal with partial duplication of chromosome arm 22q.  

PubMed

We present a case of 46,XX sex reversal in the absence of SRY but with partial duplication of chromosome 22q. The subject had multiple congenital anomalies but nearly complete masculinization of the external genitalia. Our case along with a previous case supports the existence of a gene on chromosome 22q that can trigger testis determination in the absence of SRY. We proposed that overexpression of the SOX10 gene at 22q13 might be the cause of sex reversal. We investigated 13 additional subjects with SRY-negative 46,XX sex reversal for microduplication of chromosome arm 22q in the region of SOX10 gene, but could not find evidence for it. PMID:15108202

Seeherunvong, Tossaporn; Perera, Erasmo M; Bao, Yong; Benke, Paul J; Benigno, Adelaida; Donahue, Roger P; Berkovitz, Gary D

2004-06-01

261

Maternal age-specific rates of fetal chromosomal abnormalities in Korean pregnant women of advanced maternal age  

PubMed Central

Objective To evaluate the association of maternal age with occurrence of fetal chromosomal abnormalities in Korean pregnant women of advanced maternal age (AMA). Methods A retrospective review of the amniocentesis or chorionic villous sampling (CVS) database at Gangnam and Bundang CHA Medical Centers, between January 2001 and February 2012, was conducted. This study analyzed the incidence of fetal chromosomal abnormalities according to maternal age and the correlation between maternal age and fetal chromosomal abnormalities in Korean pregnant women ?35 years of age. In addition, we compared the prevalence of fetal chromosomal abnormalities between women of AMA only and the others as the indication for amniocentesis or CVS. Results A total of 15,381 pregnant women were selected for this study. The incidence of aneuploidies increased exponentially with maternal age (P<0.0001). In particular, the risk of trisomy 21 (standard error [SE], 0.0378; odds ratio, 1.177; P<0.001) and trisomy 18 (SE, 0.0583; odds ratio, 1.182; P=0.0040) showed significant correlation with maternal age. Comparison between women of AMA only and the others as the indication for amniocentesis or CVS showed a significantly lower rate of fetal chromosomal abnormalities only in the AMA group, compared with the others (P<0.0001). Conclusion This study demonstrates that AMA is no longer used as a threshold for determination of who is offered prenatal diagnosis, but is a common risk factor for fetal chromosomal abnormalities.

Kim, Young Joo; Lee, Jee Eun; Kim, Soo Hyun; Cha, Dong Hyun

2013-01-01

262

Scoliosis and vertebral anomalies: Additional abnormal phenotypes associated with chromosome 16p11.2 rearrangement.  

PubMed

The typical chromosome 16p11.2 rearrangements are estimated to occur at a frequency of approximately 0.6% of all samples tested clinically and have been identified as a major cause of autism spectrum disorders, developmental delay, behavioral abnormalities, and seizures. Careful examination of patients with these rearrangements revealed association with abnormal head size, obesity, dysmorphism, and congenital abnormalities. In this report, we extend this list of phenotypic abnormalities to include scoliosis and vertebral anomalies. We present detailed characterization of phenotypic and radiological data of 10 new patients, nine with the 16p11.2 deletion and one with the duplication within the coordinates chr16:29,366,195 and 30,306,956 (hg19) with a minimal size of 555?kb. We discuss the phenotypical and radiological findings in our patients and review 5 previously reported patients with 16p11.2 rearrangement and similar skeletal abnormalities. Our data suggest that patients with the recurrent 16p11.2 rearrangement have increased incidence of scoliosis and vertebral anomalies. However, additional studies are required to confirm this observation and to establish the incidence of these anomalies. We discuss the potential implications of our findings on the diagnosis, surveillance and genetic counseling of patients with 16p11.2 rearrangement. © 2014 Wiley Periodicals, Inc. PMID:24458548

Al-Kateb, Hussam; Khanna, Geetika; Filges, Isabel; Hauser, Natalie; Grange, Dorothy K; Shen, Joseph; Smyser, Christopher D; Kulkarni, Shashikant; Shinawi, Marwan

2014-05-01

263

Inflammatory Cytokines in Maternal Circulation and Placenta of Chromosomally Abnormal First Trimester Miscarriages  

PubMed Central

The impact of abnormal placental karyotype on the inflammatory response within the villous tissue and peripheral circulation of women with miscarriage was evaluated. Villous (n = 38) and venous blood samples (n = 26) were obtained from women with missed miscarriage. Tissue chromosome analysis indicated 23 abnormal and 15 normal karyotypes. Concentration of tumour necrosis factor alpha (TNF?), TNF-R1 and TNF-R2, and interleukin (IL)-10 were measured using flowcytometric bead array in fresh villous homogenate, cultured villous extracts, culture medium, maternal whole blood, and plasma. Plasma TNF?/IL-10 ratios were significantly (P < 0.05) lower in miscarriages with abnormal karyotype. In the abnormal karyotype group, there were significantly higher levels of TNF? (P < 0.01), IL-10 (P < 0.01), TNF-R1 (P < 0.001), and TNF-R2 (P < 0.001) in the villous extracts and culture-conditioned medium compared to normal karyotype group. In miscarriage with abnormal karyotype, there is an exacerbated placental inflammatory response, in contrast to miscarriage of normal karyotype where maternal systemic response is increased.

Calleja-Agius, Jean; Jauniaux, Eric; Muttukrishna, Shanthi

2012-01-01

264

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

PubMed

Conventional and molecular chromosomal analyses were carried out on three populations of Apareiodon ibitiensis sampled from the hydrographic basins of the São 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 São 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

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

2009-12-01

265

Identification of X Chromosome Regions in Caenorhabditis Elegans That Contain Sex-Determination Signal Elements  

PubMed Central

The primary sex-determination signal of Caenorhabditis elegans is the ratio of X chromosomes to sets of autosomes (X/A ratio). This signal coordinately controls both sex determination and X chromosome dosage compensation. To delineate regions of X that contain counted signal elements, we examined the effect on the X/A ratio of changing the dose of specific regions of X, using duplications in XO animals and deficiencies in XX animals. Based on the mutant phenotypes of genes that are controlled by the signal, we expected that increases (in males) or decreases (in hermaphrodites) in the dose of X chromosome elements could cause sex-specific lethality. We isolated duplications and deficiencies of specific X chromosome regions, using strategies that would permit their recovery regardless of whether they affect the signal. We identified a dose-sensitive region at the left end of X that contains X chromosome signal elements. XX hermaphrodites with only one dose of this region have sex determination and dosage compensation defects, and XO males with two doses are more severely affected and die. The hermaphrodite defects are suppressed by a downstream mutation that forces all animals into the XX mode of sex determination and dosage compensation. The male lethality is suppressed by mutations that force all animals into the XO mode of both processes. We were able to subdivide this region into three smaller regions, each of which contains at least one signal element. We propose that the X chromosome component of the sex-determination signal is the dose of a relatively small number of genes.

Akerib, C. C.; Meyer, B. J.

1994-01-01

266

Whole-genome sequence of a flatfish provides insights into ZW sex chromosome evolution and adaptation to a benthic lifestyle.  

PubMed

Genetic sex determination by W and Z chromosomes has developed independently in different groups of organisms. To better understand the evolution of sex chromosomes and the plasticity of sex-determination mechanisms, we sequenced the whole genomes of a male (ZZ) and a female (ZW) half-smooth tongue sole (Cynoglossus semilaevis). In addition to insights into adaptation to a benthic lifestyle, we find that the sex chromosomes of these fish are derived from the same ancestral vertebrate protochromosome as the avian W and Z chromosomes. Notably, the same gene on the Z chromosome, dmrt1, which is the male-determining gene in birds, showed convergent evolution of features that are compatible with a similar function in tongue sole. Comparison of the relatively young tongue sole sex chromosomes with those of mammals and birds identified events that occurred during the early phase of sex-chromosome evolution. Pertinent to the current debate about heterogametic sex-chromosome decay, we find that massive gene loss occurred in the wake of sex-chromosome 'birth'. PMID:24487278

Chen, Songlin; Zhang, Guojie; Shao, Changwei; Huang, Quanfei; Liu, Geng; Zhang, Pei; Song, Wentao; An, Na; Chalopin, Domitille; Volff, Jean-Nicolas; Hong, Yunhan; Li, Qiye; Sha, Zhenxia; Zhou, Heling; Xie, Mingshu; Yu, Qiulin; Liu, Yang; Xiang, Hui; Wang, Na; Wu, Kui; Yang, Changgeng; Zhou, Qian; Liao, Xiaolin; Yang, Linfeng; Hu, Qiaomu; Zhang, Jilin; Meng, Liang; Jin, Lijun; Tian, Yongsheng; Lian, Jinmin; Yang, Jingfeng; Miao, Guidong; Liu, Shanshan; Liang, Zhuo; Yan, Fang; Li, Yangzhen; Sun, Bin; Zhang, Hong; Zhang, Jing; Zhu, Ying; Du, Min; Zhao, Yongwei; Schartl, Manfred; Tang, Qisheng; Wang, Jun

2014-03-01

267

The Epigenome of Evolving Drosophila Neo-Sex Chromosomes: Dosage Compensation and Heterochromatin Formation  

PubMed Central

Sex chromosomes originated from autosomes but have evolved a highly specialized chromatin structure. Drosophila Y chromosomes are composed entirely of silent heterochromatin, while male X chromosomes have highly accessible chromatin and are hypertranscribed as a result of dosage compensation. Here, we dissect the molecular mechanisms and functional pressures driving heterochromatin formation and dosage compensation of the recently formed neo-sex chromosomes of Drosophila miranda. We show that the onset of heterochromatin formation on the neo-Y is triggered by an accumulation of repetitive DNA. The neo-X has evolved partial dosage compensation and we find that diverse mutational paths have been utilized to establish several dozen novel binding consensus motifs for the dosage compensation complex on the neo-X, including simple point mutations at pre-binding sites, insertion and deletion mutations, microsatellite expansions, or tandem amplification of weak binding sites. Spreading of these silencing or activating chromatin modifications to adjacent regions results in massive mis-expression of neo-sex linked genes, and little correspondence between functionality of genes and their silencing on the neo-Y or dosage compensation on the neo-X. Intriguingly, the genomic regions being targeted by the dosage compensation complex on the neo-X and those becoming heterochromatic on the neo-Y show little overlap, possibly reflecting different propensities along the ancestral chromosome that formed the sex chromosome to adopt active or repressive chromatin configurations. Our findings have broad implications for current models of sex chromosome evolution, and demonstrate how mechanistic constraints can limit evolutionary adaptations. Our study also highlights how evolution can follow predictable genetic trajectories, by repeatedly acquiring the same 21-bp consensus motif for recruitment of the dosage compensation complex, yet utilizing a diverse array of random mutational changes to attain the same phenotypic outcome.

Kaiser, Vera B.; Alekseyenko, Artyom A.; Gorchakov, Andrey A.; Bachtrog, Doris

2013-01-01

268

Sex chromosomes and associated rDNA form a heterochromatic network in the polytene nuclei of Bactrocera oleae (Diptera: Tephritidae).  

PubMed

The olive fruit fly, Bactrocera oleae, has a diploid set of 2n = 12 chromosomes including a pair of sex chromosomes, XX in females and XY in males, but polytene nuclei show only five polytene chromosomes, obviously formed by five autosome pairs. Here we examined the fate of the sex chromosomes in the polytene complements of this species using fluorescence in situ hybridization (FISH) with the X and Y chromosome-derived probes, prepared by laser microdissection of the respective chromosomes from mitotic metaphases. Specificity of the probes was verified by FISH in preparations of mitotic chromosomes. In polytene nuclei, both probes hybridized strongly to a granular heterochromatic network, indicating thus underreplication of the sex chromosomes. The X chromosome probe (in both female and male nuclei) highlighted most of the granular mass, whereas the Y chromosome probe (in male nuclei) identified a small compact body of this heterochromatic network. Additional hybridization signals of the X probe were observed in the centromeric region of polytene chromosome II and in the telomeres of six polytene arms. We also examined distribution of the major ribosomal DNA (rDNA) using FISH with an 18S rDNA probe in both mitotic and polytene chromosome complements of B. oleae. In mitotic metaphases, the probe hybridized exclusively to the sex chromosomes. The probe signals localized a discrete rDNA site at the end of the short arm of the X chromosome, whereas they appeared dispersed over the entire dot-like Y chromosome. In polytene nuclei, the rDNA was found associated with the heterochromatic network representing the sex chromosomes. Only in nuclei with preserved nucleolar structure, the probe signals were scattered in the restricted area of the nucleolus. Thus, our study clearly shows that the granular heterochromatic network of polytene nuclei in B. oleae is formed by the underreplicated sex chromosomes and associated rDNA. PMID:22825842

Drosopoulou, Elena; Nakou, Ifigeneia; Síchová, Jindra; Kubí?ková, Svatava; Marec, František; Mavragani-Tsipidou, Penelope

2012-06-01

269

Sex chromosome loss and aging: In situ hybridization studies on human interphase nuclei  

Microsoft Academic Search

A total of 1,000 lymphocyte interphase nuclei per proband from 90 females and 138 males age 1 wk to 93 years were analyzed by in situ hybridization for loss of the X and Y chromosomes, respectively. Both sex chromosomes showed an age-dependent loss. In males, Y hypoploidy was very low up to age 15 years (0.05%) but continuously increased to

M. Guttenbach; B. Koschorz; U. Bernthaler

1995-01-01

270

Molecular analysis of sex chromosome-linked mutants in the silkworm Bombyx mori  

Microsoft Academic Search

In Bombyx mori, the W chromosome determines the female sex. A few W chromosome-linked mutations that cause masculinization of the female\\u000a genitalia have been found. In female antennae of a recently isolated mutant, both female-type and male-type Bmdsx mRNAs were expressed, and BmOr1 (bombykol receptor) and BmOr3 (bombykal receptor), which are predominantly expressed in the antennae of male moths, were

Tsuguru Fujii; Hiroaki Abe; Toru Shimada

2010-01-01

271

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

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.

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

2003-01-01

272

Complex chromosomal abnormalities in a patient with HTLV-1 positive T-cell leukemia  

SciTech Connect

HTLV-1 positive adult T-cell leukemia (ATL) is associated with numerous chromosomal abnormalities. The chromosomal rearrangements can be extremely complex and additional material is often present, making precise identification by routine cytogenetic techniques difficult. We report a case of ATL that was established of bone marrow cells by both QFQ and GTG banding techniques revealed a highly complex 49,XX,der(2)t(2;?)(q37;?),+5,+2mar karyotype in the dividing cells. The identical cytogenetic findings were also seen in unstimulated peripheral blood collected one week later. Using the FISH-technique, we applied spectrum green-labeled No. 1- and No. 7-specific WCP, spectrum orange-labeled No. 2- and No. 5-specific WCP (GIBCO/BRL, Gaithersburg, MD) and biotin-labeled No. 18-specific WCP (Oncor, Gaithersburg, MD) to metaphase chromosomes. The large marker chromosome was identified as an extra 1q arm, the material attached to the distal 2q was additional 7q. The presence of three No. 5 chromosomes was verified and the small marker was determined to be an extra partial 5p in Robertsonian translocation with an additional partial 18q arm. The karyotype was revised to 49,XX,+1q,der(2)t(2;7)(q37;q22),+5,+t(5;18)(p14{r_arrow}p11::q11{r_arrow}q12). Identification of the numerous chromosomal anomalies associated with the disease by molecular techniques shall lead to a better understanding of this deadly cancer.

Hyde, P.; Macera, M.J.; Gogineni, S.K. [Long Island College Hospital, Brooklyn, NY (United States)] [and others

1994-09-01

273

Prader-Willi-like phenotypes: a systematic review of their chromosomal abnormalities.  

PubMed

Prader-Willi syndrome (PWS) is caused by the lack of expression of genes located on paternal chromosome 15q11-q13. This lack of gene expression may be due to a deletion in this chromosomal segment, to maternal uniparental disomy of chromosome 15, or to a defect in the imprinting center on 15q11-q13. PWS is characterized by hypotonia during the neonatal stage and in childhood, accompanied by a delay in neuropsychomotor development. Overeating, obesity, and mental deficiency arise later on. The syndrome has a clinical overlap with other diseases, which makes it difficult to accurately diagnose. The purpose of this article is to review the Prader-Willi-like phenotype in the scientific literature from 2000 to 2013, i.e., to review the cases of PWS caused by chromosomal abnormalities different from those found on chromosome 15. A search was carried out using the "National Center for Biotechnology Information" (www.pubmed.com) and "Scientific Electronic Library Online (www.scielo.br) databases and combinations of key words such as "Prader-Willi-like phenotype" and "Prader-Willi syndrome phenotype". Editorials, letters, reviews, and guidelines were excluded. Articles chosen contained descriptions of patients diagnosed with the PWS phenotype but who were negative for alterations on 15q11-q13. Our search found 643 articles about PWS, but only 14 of these matched with the Prader-Willi-like phenotype and with the selected years of publication (2000-2013). If two or more articles reported the same chromosomal alterations for Prader-Willi-like phenotype, the most recent was chosen. Twelve articles of 14 were case reports and 2 reported series of cases. PMID:24737477

Rocha, C F; Paiva, C L A

2014-01-01

274

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

SciTech Connect

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.

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

1995-02-13

275

Z and W sex chromosomes in the cane toad ( Bufo marinus )  

Microsoft Academic Search

The cane toad (Bufo marinus) is one of the most notorious animal pests encountered in Australia. Members of the genus Bufo historically have been regarded as having genotypic sex determination with male homogamety\\/female heterogamety. Nevertheless,\\u000a as with many toads, karyotypic analyses of the cane toad have so far failed to identify heteromorphics sex chromosomes. In\\u000a this study, we used comparative

John Abramyan; Tariq Ezaz; Jennifer A. Marshall Graves; Peter Koopman

2009-01-01

276

Sex Chromosomes Regulate Nighttime Sleep Propensity during Recovery from Sleep Loss in Mice  

PubMed Central

Sex differences in spontaneous sleep amount are largely dependent on reproductive hormones; however, in mice some sex differences in sleep amount during the active phase are preserved after gonadectomy and may be driven by non-hormonal factors. In this study, we sought to determine whether or not these sex differences are driven by sex chromosome complement. Mice from the four core genotype (FCG) mouse model, whose sex chromosome complement (XY, XX) is independent of phenotype (male or female), were implanted with electroencephalographic (EEG) and electromyographic (EMG) electrodes for the recording of sleep-wake states and underwent a 24-hr baseline recording followed by six hours of forced wakefulness. During baseline conditions in mice whose gonads remained intact, males had more total sleep and non-rapid eye movement sleep than females during the active phase. Gonadectomized FCG mice exhibited no sex differences in rest-phase sleep amount; however, during the mid-active-phase (nighttime), XX males had more spontaneous non-rapid eye movement (NREM) sleep than XX females. The XY mice did not exhibit sex differences in sleep amount. Following forced wakefulness there was a change in the factors regulating sleep. XY females slept more during their mid-active phase siestas than XX females and had higher NREM slow wave activity, a measure of sleep propensity. These findings suggest that the process that regulates sleep propensity is sex-linked, and that sleep amount and sleep propensity are regulated differently in males and females following sleep loss.

Pinckney, Lennisha; Paul, Ketema N.

2013-01-01

277

Sex-dependent selection differentially shapes genetic variation on and off the guppy Y chromosome.  

PubMed

Because selection is often sex-dependent, alleles can have positive effects on fitness in one sex and negative effects in the other, resulting in intralocus sexual conflict. Evolutionary theory predicts that intralocus sexual conflict can drive the evolution of sex limitation, sex-linkage, and sex chromosome differentiation. However, evidence that sex-dependent selection results in sex-linkage is limited. Here, we formally partition the contribution of Y-linked and non-Y-linked quantitative genetic variation in coloration, tail, and body size of male guppies (Poecilia reticulata)-traits previously implicated as sexually antagonistic. We show that these traits are strongly genetically correlated, both on and off the Y chromosome, but that these correlations differ in sign and magnitude between both parts of the genome. As predicted, variation in attractiveness was found to be associated with the Y-linked, rather than with the non-Y-linked component of genetic variation in male ornamentation. These findings show how the evolution of Y-linkage may be able to resolve sexual conflict. More generally, they provide unique insight into how sex-specific selection has the potential to differentially shape the genetic architecture of fitness traits across different parts of the genome. PMID:21790565

Postma, Erik; Spyrou, Nicolle; Rollins, Lee Ann; Brooks, Robert C

2011-08-01

278

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

NSDL National Science Digital Library

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.

2008-10-06

279

A new neurological syndrome with mental retardation, choreoathetosis, and abnormal behavior maps to chromosome Xp11.  

PubMed

Choreoathetosis is a major clinical feature in only a small number of hereditary neurological disorders. We define a new X-linked syndrome with a unique clinical picture characterized by mild mental retardation, choreoathetosis, and abnormal behavior. We mapped the disease in a four-generation pedigree to chromosome Xp11 by linkage analysis and defined a candidate region containing a number of genes possibly involved in neuronal signaling, including a potassium channel gene and a neuronal G protein-coupled receptor. PMID:10521307

Reyniers, E; Van Bogaert, P; Peeters, N; Vits, L; Pauly, F; Fransen, E; Van Regemorter, N; Kooy, R F

1999-11-01

280

Cognition and the Sex Chromosomes: Studies in Turner Syndrome  

Microsoft Academic Search

Turner syndrome (TS) is a human genetic disorder involving females who lack all or part of one X chromosome. The complex phenotype includes ovarian failure, a characteristic neurocognitive profile and typical physical features. TS features are associated not only with complete monosomy X but also with partial deletions of either the short (Xp) or long (Xq) arm (partial monosomy X).

Judith Ross; David Roeltgen; Andrew Zinn

2006-01-01

281

Chromosome analysis of postimplantation stage embryos for studying possible causes of developmental abnormalities in nonobese diabetic mice.  

PubMed

The chromosomes of postimplantation stage embryos of nonobese diabetic (NOD) mice were analyzed to investigate the causal mechanism of congenital anomalies in diabetic pregnancies. Postimplantation stage embryos (day 12 of gestation) in diabetic (NOD-DM) and nondiabetic (NOD-N) NOD mice had either a high or low incidence of chromosomal abnormalities. A large majority of externally normal embryos from NOD-DM and NOD-N mice had low incidences. A high incidence of chromosomal abnormalities was found in externally abnormal embryos of NOD-DM and NOD-N mice, and in a smaller number of externally normal NOD-N and NOD-DM embryos. No control ICR embryo manifested a high incidence of chromosomal abnormalities. In the NOD-DM embryos, the chromosomes appeared to be influenced by long-term maternal diabetic conditions, while high incidences of chromosomal abnormalities in the NOD-N embryos suggested a probable cause by other factor(s) (e.g. a genetic predisposition) or by a very mild diabetic condition because the NOD-N mice were prediabetic. PMID:1797135

Tatewaki, R; Otani, H; Ando, S; Hashimoto, R; Naora, H; Tanaka, O

1991-01-01

282

Sex chromosome aberrations and stature: deduction of the principal factors involved in the determination of adult height  

Microsoft Academic Search

Although sex chromosome aberrations are frequently associated with statural changes, the underlying factors have not been clarified. To define the factors leading to the statural changes, we took the following three steps: (1) determination of the mean adult height in non-mosaic Caucasian patients with sex chromosome aberrations reported in the literature (assessment of genetic height potential); (2) assessment of the

Tsutomu Ogata; Nobutake Matsuo

1993-01-01

283

Heterochromatin, sex chromosomes and rRNA gene clusters in Coprophanaeus beetles (Coleoptera, Scarabaeidae).  

PubMed

Repetitive DNA sequences constitute a high fraction of eukaryotic genomes and are considered a key component for the chromosome and karyotype evolution. For a better understanding of their evolutionary role in beetles, we examined the chromosomes of 5 species of the genus Coprophanaeus by C-banding, fluorochrome staining CMA?/DA/DAPI, and fluorescence in situ hybridization (FISH) with probes for 18S and 5S rRNA genes. The Coprophanaeus species have identical chromosome numbers and a conserved chromosome morphology. However, they show different sex chromosome forms, XY, Xy, XY(p), and heterochromatin seems to be involved in the origin and diversification of these forms. C-banding showed primarily the presence of diphasic chromosomes in all species examined. After CMA?/DA/DAPI staining, 1-9 autosomal pairs showed CMA?-positive blocks depending on the species, while DAPI-positive blocks were detected only in Coprophanaeusdardanus. FISH mapping revealed 5S rDNA signals in one autosomal pair in each species, whereas the number of pairs with 18S rDNA signals varied from 1-8 between the Coprophanaeus species. Our results suggest that distinct genetic mechanisms had been involved in the karyotype evolution of Coprophanaeus species, i.e. mechanisms maintaining the conserved number of 5S rDNA clusters and those generating variability in the amount of heterochromatin, sex chromosome forms, and distribution of 18S rDNA clusters. PMID:22797215

Oliveira, S G; Cabral-de-Mello, D C; Arcanjo, A P; Xavier, C; Souza, M J; Martins, C; Moura, R C

2012-01-01

284

Developmental abnormalities of the gonad and abnormal sex hormone concentrations in juvenile alligators from contaminated and control lakes in Florida.  

PubMed Central

The reproductive development of alligators from a contaminated and a control lake in central Florida was examined. Lake Apopka is adjacent to an EPA Superfund site, listed due to an extensive spill of dicofol and DDT or its metabolites. These compounds can act as estrogens. Contaminants in the lake also have been derived from extensive agricultural activities around the lake that continue today and a sewage treatment facility associated with the city of Winter Garden, Florida. We examined the hypothesis that an estrogenic contaminant has caused the current failure in recruitment of alligators on Lake Apopka. Supporting data include the following: At 6 months of age, female alligators from Lake Apopka had plasma estradiol-17 beta concentrations almost two times greater than normal females from the control lake, Lake Woodruff. The Apopka females exhibited abnormal ovarian morphology with large numbers of polyovular follicles and polynuclear oocytes. Male juvenile alligators had significantly depressed plasma testosterone concentrations comparable to levels observed in normal Lake Woodruff females but more than three times lower than normal Lake Woodruff males. Additionally, males from Lake Apopka had poorly organized testes and abnormally small phalli. The differences between lakes and sexes in plasma hormone concentrations of juvenile alligators remain even after stimulation with luteinizing hormone. Our data suggest that the gonads of juveniles from Lake Apopka have been permanently modified in ovo, so that normal steroidogenesis is not possible, and thus normal sexual maturation is unlikely. Images p680-a Figure 1. Figure 2. Figure 3. A Figure 3. B Figure 3. C Figure 4. A Figure 4. B Figure 4. C Figure 4. D Figure 5. A Figure 5. B Figure 5. C

Guillette, L J; Gross, T S; Masson, G R; Matter, J M; Percival, H F; Woodward, A R

1994-01-01

285

Embryo Sexing and Sex Chromosomal Chimerism Analysis by Loop-Mediated Isothermal Amplification in Cattle and Water Buffaloes  

PubMed Central

Abstract In domestic animals of the family Bovidae, sex preselection of offspring has been demanded for convenience of milk/beef production and animal breeding. Development of the nonsurgical embryo transfer technique and sexing methods of preimplantation embryos made it possible. Sexing based on detection of Y chromosome-specific DNA sequences is considered the most reliable method to date. PCR enables amplification of a target sequence from a small number of blastomeres. However, it requires technical skill and is time consuming. Furthermore, PCR has the risk of false positives because of DNA contamination during handling of the PCR products in duplicate PCR procedures and/or electrophoresis. Therefore, for embryo sexing to become widely used in the cattle embryo transfer industry, a simple, rapid and precise sexing method needs to be developed. Loop-mediated isothermal amplification (LAMP) is a novel DNA amplification method, and the reaction is carried out under isothermal conditions (range, 60 to 65 C) using DNA polymerase with strand displacement activity. When the target DNA is amplified by LAMP, a white precipitate derived from magnesium pyrophosphate (a by-product of the LAMP reaction) is observed. It is noteworthy that LAMP does not need special reagents or electrophoresis to detect the amplified DNA. This review describes the development and application of an embryo sexing method using LAMP in cattle and water buffaloes.

HIRAYAMA, Hiroki; KAGEYAMA, Soichi; MORIYASU, Satoru; SAWAI, Ken; MINAMIHASHI, Akira

2013-01-01

286

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

PubMed

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

Kovaleva, Natalia V; Mutton, David E

2005-04-01

287

The Organizational Concept and Vertebrates without Sex Chromosomes  

Microsoft Academic Search

The diversity in vertebrate reproductive patterns provides natural experiments that yield new insights into behavioral endocrinology. Discussed here is the generality of the concept of an organizing sex during sexual differentiation. In its present form the Organizational Concept emphasizes hormonally induced organization of the male phenotype, with the female phenotype being the neutral or default condition. Does this concept extend

David Crews

1993-01-01

288

Fatness QTL on chicken chromosome 5 and interaction with sex  

Microsoft Academic Search

Quantitative trait loci (QTL) affecting fatness in male chickens were previously identified on chromosome 5 (GGA5) in a three-generation design derived from two experimental chicken lines divergently selected for abdominal fat weight. A new design, established from the same pure lines, produced 407 F2 progenies (males and females) from 4 F1-sire families. Body weight and abdominal fat were measured on

Behnam Abasht; Frédérique Pitel; Sandrine Lagarrigue; Elisabeth Le Bihan-Duval; Pascale Le Roy; Olivier Demeure; Florence Vignoles; Jean Simon; Larry Cogburn; Sammy Aggrey; Alain Vignal; Madeleine Douaire

2006-01-01

289

High Incidence of Sperm Sex Chromosomes Aneuploidies in Two Patients with Klinefelter's Syndrome  

Microsoft Academic Search

In this study we have investigated the arrangement of sex chro- mosomes in sperm from two severe oligozoospermic patients, appar- ently affected by the classic form of Klinefelter's syndrome (KS). Multicolor fluorescence in situ hybridization has been used to recog- nize chromosomes X, Y, and 8 in sperm from patients and 10 fertile men with normal 46,XY karyotype. In patients

C. FORESTA; C. GALEAZZI; A. BETTELLA; M. STELLA; C. SCANDELLARI

2010-01-01

290

Latrunculin A Treatment Prevents Abnormal Chromosome Segregation for Successful Development of Cloned Embryos  

PubMed Central

Somatic cell nuclear transfer to an enucleated oocyte is used for reprogramming somatic cells with the aim of achieving totipotency, but most cloned embryos die in the uterus after transfer. While modifying epigenetic states of cloned embryos can improve their development, the production rate of cloned embryos can also be enhanced by changing other factors. It has already been shown that abnormal chromosome segregation (ACS) is a major cause of the developmental failure of cloned embryos and that Latrunculin A (LatA), an actin polymerization inhibitor, improves F-actin formation and birth rate of cloned embryos. Since F-actin is important for chromosome congression in embryos, here we examined the relation between ACS and F-actin in cloned embryos. Using LatA treatment, the occurrence of ACS decreased significantly whereas cloned embryo-specific epigenetic abnormalities such as dimethylation of histone H3 at lysine 9 (H3K9me2) could not be corrected. In contrast, when H3K9me2 was normalized using the G9a histone methyltransferase inhibitor BIX-01294, the Magea2 gene—essential for normal development but never before expressed in cloned embryos—was expressed. However, this did not increase the cloning success rate. Thus, non-epigenetic factors also play an important role in determining the efficiency of mouse cloning.

Terashita, Yukari; Yamagata, Kazuo; Tokoro, Mikiko; Itoi, Fumiaki; Wakayama, Sayaka; Li, Chong; Sato, Eimei; Tanemura, Kentaro; Wakayama, Teruhiko

2013-01-01

291

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

Microsoft Academic Search

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

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

2009-01-01

292

The origin of mitotic sex-chromosome association in the brush-tailed possum, Trichosurus vulpecula (marsupalia:phalangeridae).  

PubMed

Nonrandom associations between the sex chromosomes of the brush-tailed possum, Trichosurus vulpecula, were found to be due to association of nucleolar organizer regions (NOR's) on the X and Y chromosomes. NOR association was also observed between an autosome and the X chromosome. These findings, based on silver staining, are in contrast to the report of MURRAY (1977), who observed sex-chromosome association in this animal and indicated that these nonrandom associations may reflect an association between heterochromatic regions during interphase. We observed only two pairs of NOR's per cell in this animal, one autosomal and one on the sex chromosomes, rather than the several such regions observed by MURRAY, who used an N-banding technique. We discuss the problem of nonhomologous chromosome association in mammalian cells as influenced by heterochromatin and NOR's and find little support for nonhomologous chromosome associations at mitotic metaphase due to heterochromatin association. PMID:6186438

Stock, A D; Mengden, G A

1982-01-01

293

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

SciTech Connect

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.

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

294

Influence of sex chromosome constitution on the genomic imprinting of germ cells.  

PubMed

Germ cells in XY male mice establish site-specific methylation on imprinted genes during spermatogenesis, whereas germ cells in XX females establish their imprints in growing oocytes. We showed previously that in vitro, sex-specific methylation patterns of pluripotent stem cell lines derived from germ cells were influenced more by the sex chromosome constitution of the cells themselves than by the gender of the embryo from which they had been derived. To see whether the same situation would prevail in vivo, we have now determined the methylation status of H19 expressed from the maternal allele, and the expression and methylation status of a paternally expressed gene Peg3, in germ cells from sex-reversed and control embryos. For these imprinted genes, we conclude that the female imprint is a response of the germ cells to undergoing oogenesis, rather than to their XX chromosome constitution. Similarly, both our XY and our sex-reversed XX male germ cells clearly showed a male rather than a female pattern of DNA methylation; here, however, the sex chromosome constitution had a significant effect, with XX male germ cells less methylated than the XY controls. PMID:16847261

Durcova-Hills, Gabriela; Hajkova, Petra; Sullivan, Stephen; Barton, Sheila; Surani, M Azim; McLaren, Anne

2006-07-25

295

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

PubMed Central

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.

Yin, Tongming; DiFazio, Stephen P.; Gunter, Lee E.; Zhang, Xinye; Sewell, Michell M.; Woolbright, Scott A.; Allan, Gery J.; Kelleher, Collin T.; Douglas, Carl J.; Wang, Mingxiu; Tuskan, Gerald A.

2008-01-01

296

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

SciTech Connect

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.

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

297

Geographic variation in sex-chromosome differentiation in the common frog (Rana temporaria).  

PubMed

In sharp contrast with birds and mammals, sex-determination systems in ectothermic vertebrates are often highly dynamic and sometimes multifactorial. Both environmental and genetic effects have been documented in common frogs (Rana temporaria). One genetic linkage group, mapping to the largest pair of chromosomes and harbouring the candidate sex-determining gene Dmrt1, associates with sex in several populations throughout Europe, but association varies both within and among populations. Here, we show that sex association at this linkage group differs among populations along a 1500-km transect across Sweden. Genetic differentiation between sexes is strongest (FST  = 0.152) in a northern-boreal population, where male-specific alleles and heterozygote excesses (FIS  = -0.418 in males, +0.025 in females) testify to a male-heterogametic system and lack of X-Y recombination. In the southernmost population (nemoral climate), in contrast, sexes share the same alleles at the same frequencies (FST  = 0.007 between sexes), suggesting unrestricted recombination. Other populations show intermediate levels of sex differentiation, with males falling in two categories: some cluster with females, while others display male-specific Y haplotypes. This polymorphism may result from differences between populations in the patterns of X-Y recombination, co-option of an alternative sex-chromosome pair, or a mixed sex-determination system where maleness is controlled either by genes or by environment depending on populations or families. We propose approaches to test among these alternative models, to disentangle the effects of climate and phylogeography on the latitudinal trend, and to sort out how this polymorphism relates to the 'sexual races' described in common frogs in the 1930s. PMID:24935195

Rodrigues, Nicolas; Merilä, Juha; Patrelle, Cécile; Perrin, Nicolas

2014-07-01

298

Differentiation of Z and W chromosomes revealed by replication banding and FISH mapping of sex-chromosome-linked DNA markers in the cassowary (Aves, Ratitae).  

PubMed

We identified sex chromosomes of the double-wattled cassowary (Casuarius casuarius) by a replication banding method. The acrocentric Z chromosome, the fifth largest pair in males and slightly smaller W chromosome show no sign of heterochromatinization and share a nearly identical banding pattern in the distal half of the long arm. These chromosomes were further characterized by FISH with three probes linked either to Z or W chromosome in most avian species examined thus far. Contrary to the situation in the chicken, we obtained positive signals with Z-specific ZOV3 and W-specific EEO.6 in the distal region of both Z and W chromosomes. However, IREBP signals localized to the proximal half of the Z chromosome were not detected on the W chromosome. Thus, structural rearrangements such as deletions and inversions might have been the initial step of W chromosome differentiation from an ancestral homomorphic pair in this species. PMID:10628664

Nishida-Umehara, C; Fujiwara, A; Ogawa, A; Mizuno, S; Abe, S; Yoshida, M C

1999-01-01

299

Four loci on abnormal chromosome 10 contribute to meiotic drive in maize.  

PubMed Central

We provide a genetic analysis of the meiotic drive system on maize abnormal chromosome 10 (Ab10) that causes preferential segregation of specific chromosomal regions to the reproductive megaspore. The data indicate that at least four chromosomal regions contribute to meiotic drive, each providing distinct functions that can be differentiated from each other genetically and/or phenotypically. Previous reports established that meiotic drive requires neocentromere activity at specific tandem repeat arrays (knobs) and that two regions on Ab10 are involved in trans-activating neocentromeres. Here we confirm and extend data suggesting that only one of the neocentromere-activating regions is sufficient to move many knobs. We also confirm the localization of a locus/loci on Ab10, thought to be a prerequisite for meiotic drive, which promotes recombination in structural heterozygotes. In addition, we identified two new and independent functions required for meiotic drive. One was identified through the characterization of a deletion derivative of Ab10 [Df(L)] and another as a newly identified meiotic drive mutation (suppressor of meiotic drive 3). In the absence of either function, meiotic drive is abolished but neocentromere activity and the recombination effect typical of Ab10 are unaffected. These results demonstrate that neocentromere activity and increased recombination are not the only events required for meiotic drive.

Hiatt, Evelyn N; Dawe, R Kelly

2003-01-01

300

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

PubMed

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 normal female diploid cells or all X chromosomes in excess of one in sex chromosome aneuploids. Our previous studies showing that XIST expression does not eventuate the inactivation of X-linked genes in fetal bovine testis had suggested that XIST expression may not be an indicator of X inactivation in this species. In this study, we used a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) approach on cultures of bovine cells with varying sex chromosome constitution (XY, XX, XXY and XXX) to test whether the levels of XIST expressed conform to the number of late replicating (inactive) X chromosomes displayed by proliferating cells in these cultures. Expression patterns of four X-linked genes, including hypoxanthine phosphorybosyl transferase (HPRT), glucose-6-phosphate dehydrogenase (G6PD), zinc finger protein locus on the X (ZFX). and 'selected mouse cDNA on the X' (SMCX), in all these cells were also tested. Results showed that XIST expression was significantly higher (p < 0.05) in XXX cells compared to XX and XXY cells and that G6PD. HPRT, and SMCX loci are subject to X inactivation. The significantly higher levels of ZFX expressed in XXX cells compared to XX and XXY cells (p < 0.05) confirmed that this bovine locus, as human ZFX, escapes X inactivation. However, the levels of XIST and ZFX expressed were not proportional to the X chromosome load in these cells suggesting that X-linked loci escaping inactivation may be regulated at transcription (or post-transcription) level by mechanisms that prevent gene-specific product accumulation beyond certain levels in sex chromosome aneuploids. PMID:15125640

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

2004-01-01

301

Sex chromosome mosaicism in males carrying Y chromosome long arm deletions.  

PubMed

Microdeletions of the long arm of the Y chromosome (Yq) are a common cause of male infertility. Since large structural rearrangements of the Y chromosome are commonly associated with a 45,XO/46,XY chromosomal mosaicism, we studied whether submicroscopic Yq deletions could also be associated with the development of 45,XO cell lines. We studied blood samples from 14 infertile men carrying a Yq microdeletion as revealed by polymerase chain reaction (PCR). Patients were divided into two groups: group 1 (n = 6), in which karyotype analysis demonstrated a 45,X/46,XY mosaicism, and group 2 (n = 8) with apparently a normal 46,XY karyotype. 45,XO cells were identified by fluorescence in-situ hybridization (FISH) using X and Y centromeric probes. Lymphocytes from 11 fertile men were studied as controls. In addition, sperm cells were studied in three oligozoospermic patients in group 2. Our results showed that large and submicroscopic Yq deletions were associated with significantly increased percentages of 45,XO cells in lymphocytes and of sperm cells nullisomic for gonosomes, especially for the Y chromosome. Moreover, two isodicentric Y chromosomes, classified as normal by cytogenetic methods, were detected. Therefore, Yq microdeletions may be associated with Y chromosomal instability leading to the formation of 45,XO cell lines. PMID:11098026

Siffroi, J P; Le Bourhis, C; Krausz, C; Barbaux, S; Quintana-Murci, L; Kanafani, S; Rouba, H; Bujan, L; Bourrouillou, G; Seifer, I; Boucher, D; Fellous, M; McElreavey, K; Dadoune, J P

2000-12-01

302

The chromatin landscape of Drosophila: comparisons between species, sexes, and chromosomes.  

PubMed

The chromatin landscape is key for gene regulation, but little is known about how it differs between sexes or between species. Here, we study the sex-specific chromatin landscape of Drosophila miranda, a species with young sex chromosomes, and compare it with Drosophila melanogaster. We analyze six histone modifications in male and female larvae of D. miranda (H3K4me1, H3K4me3, H3K36me3, H4K16ac, H3K27me3, and H3K9me2), and define seven biologically meaningful chromatin states that show different enrichments for transcribed and silent genes, repetitive elements, housekeeping, and tissue-specific genes. The genome-wide distribution of both active and repressive chromatin states differs between males and females. In males, active chromatin is enriched on the X, relative to females, due to dosage compensation of the hemizygous X. Furthermore, a smaller fraction of the euchromatic portion of the genome is in a repressive chromatin state in males relative to females. However, sex-specific chromatin states appear not to explain sex-biased expression of genes. Overall, conservation of chromatin states between male and female D. miranda is comparable to conservation between D. miranda and D. melanogaster, which diverged >30 MY ago. Active chromatin states are more highly conserved across species, while heterochromatin shows very low levels of conservation. Divergence in chromatin profiles contributes to expression divergence between species, with ?26% of genes in different chromatin states in the two species showing species-specific or species-biased expression, an enrichment of approximately threefold over null expectation. Our data suggest that heteromorphic sex chromosomes in males (that is, a hypertranscribed X and an inactivated Y) may contribute to global redistribution of active and repressive chromatin marks between chromosomes and sexes. PMID:24840603

Brown, Emily J; Bachtrog, Doris

2014-07-01

303

Robertsonian polymorphism, B chromosomes variation and sex chromosomes heteromorphism in the african water rat Dasymys (Rodentia, Muridae).  

PubMed

Chromosome banding analysis (G- and C-bands) of Dasymys rufulus from Senegal, Mali and the Ivory Coast, and D. cf. incomtus from Eastern and South-western Ethiopia was carried out. The diploid numbers (2N) in the former species range between 36 and 39 due to the presence of 0-3 small biarmed heterochromatic B chromosomes, resulting in a corresponding variation of the number of autosomal arms (NFa) between 44 and 50. The basic autosomal set was, however, constant and identical in these specimens. The karyotypes of D. cf. incomtus from Eastern and Western Ethiopia were found to be different (2N = 40 and 38, respectively). Comparison of G-banding patterns of the species studied revealed that they differ from each others by 1-2 Rb fusions/fissions, one paracentric inversion and heteromorphous sex chromosomes resulting from addition/deletion of heterochromatic blocks (X) and pericentric inversion (Y). In the light of the available chromosome banding data, the significance of intraspecies karyotypic variability within D. cf. incomtus and its relevance to the systematics of the genus are discussed. PMID:11196132

Volobouev, V T; Sicard, B; Aniskin, V M; Gautun, J C; Granjon, L

2000-01-01

304

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

PubMed

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

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

2013-12-01

305

Comparative cytogenetic analysis of sex chromosomes in several Canidae species using zoo-FISH.  

PubMed

Sex chromosome differentiation began early during mammalian evolution. The karyotype of almost all placental mammals living today includes a pair of heterosomes: XX in females and XY in males. The genomes of different species may contain homologous synteny blocks indicating that they share a common ancestry. One of the tools used for their identification is the Zoo-FISH technique. The aim of the study was to determine whether sex chromosomes of some members of the Canidae family (the domestic dog, the red fox, the arctic fox, an interspecific hybrid: arctic fox x red fox and the Chinese raccoon dog) are evolutionarily conservative. Comparative cytogenetic analysis by Zoo-FISH using painting probes specific to domestic dog heterosomes was performed. The results show the presence of homologous synteny covering the entire structures of the X and the Y chromosomes. This suggests that sex chromosomes are conserved in the Canidae family. The data obtained through Zoo-FISH karyotype analysis append information obtained using other comparative genomics methods, giving a more complete depiction of genome evolution. PMID:22428301

Bugno-Poniewierska, Monika; Sojecka, Agnieszka; Pawlina, Klaudia; Jakubczak, Andrzej; Jezewska-Witkowska, Grazyna

2012-01-01

306

Chromosomal microarray analysis as a first-line test in pregnancies with a priori low risk for the detection of submicroscopic chromosomal abnormalities  

PubMed Central

In this study, we aimed to explore the utility of chromosomal microarray analysis (CMA) in groups of pregnancies with a priori low risk for detection of submicroscopic chromosome abnormalities, usually not considered an indication for testing, in order to assess whether CMA improves the detection rate of prenatal chromosomal aberrations. A total of 3000 prenatal samples were processed in parallel using both whole-genome CMA and conventional karyotyping. The indications for prenatal testing included: advanced maternal age, maternal serum screening test abnormality, abnormal ultrasound findings, known abnormal fetal karyotype, parental anxiety, family history of a genetic condition and cell culture failure. The use of CMA resulted in an increased detection rate regardless of the indication for analysis. This was evident in high risk groups (abnormal ultrasound findings and abnormal fetal karyotype), in which the percentage of detection was 5.8% (7/120), and also in low risk groups, such as advanced maternal age (6/1118, 0.5%), and parental anxiety (11/1674, 0.7%). A total of 24 (0.8%) fetal conditions would have remained undiagnosed if only a standard karyotype had been performed. Importantly, 17 (0.6%) of such findings would have otherwise been overlooked if CMA was offered only to high risk pregnancies.The results of this study suggest that more widespread CMA testing of fetuses would result in a higher detection of clinically relevant chromosome abnormalities, even in low risk pregnancies. Our findings provide substantial evidence for the introduction of CMA as a first-line diagnostic test for all pregnant women undergoing invasive prenatal testing, regardless of risk factors.

Fiorentino, Francesco; Napoletano, Stefania; Caiazzo, Fiorina; Sessa, Mariateresa; Bono, Sara; Spizzichino, Letizia; Gordon, Anthony; Nuccitelli, Andrea; Rizzo, Giuseppe; Baldi, Marina

2013-01-01

307

Effect of separating bull semen into X and Y chromosome-bearing fractions on the sex ratio of resulting embryos.  

PubMed Central

Seventy-six, day 12 to day 15 bovine embryos, collected from 14 donors which had been inseminated with either X or Y chromosome-bearing spermatozoa fractions of semen separated by a thermal convection counterstreaming sedimentation and forced convection galvanization process, were processed for sexing by chromosomal analysis. Fifty-seven embryos were sexed; 20 from Y chromosome-bearing and 37 from X chromosome-bearing fractions of semen. Statistical analysis of the sexing data indicated that there was no significant difference in the male: female ratio for donors receiving male fractions compared to those receiving female fractions. The Y chromosome-bearing fractions produced a male: female ratio that was indistinguishable from the expected 1:1 ratio. However, the X chromosome-bearing fractions of semen produced a highly significant deviation from the expected 1:1 ratio towards the male.

Hagele, W C; Hare, W C; Singh, E L; Grylls, J L; Abt, D A

1984-01-01

308

Preimplantation genetic diagnosis increases the implantation rate in human in vitro fertilization by avoiding the transfer of chromosomally abnormal embryos  

Microsoft Academic Search

Objective: To verify the percentage of chromosomally abnormal preimplantation embryos in patients with a poor prognosis and possibly to increase the chance of implantation by selecting chromosomally normal embryos.Design: A prospective, randomized, controlled study.Setting: In vitro fertilization program at the Reproductive Medicine Unit of the Societá Italiana Studi Medicina della Riproduzione, Bologna, Italy.Patient(s): In a total of 28 stimulated cycles,

Luca Gianaroli; M. Cristina Magli; Anna Pia Ferraretti; Agnese Fiorentino; John Garrisi; Santiago Munné

1997-01-01

309

Dosage Effects of X and Y Chromosomes on Language and Social Functioning in Children with Supernumerary Sex Chromosome Aneuploidies: Implications for Idiopathic Language Impairment and Autism Spectrum Disorders  

ERIC Educational Resources Information Center

Background: Supernumerary sex chromosome aneuploidies (X/Y-aneuploidies), the presence of extra X and/or Y chromosomes, are associated with heightened rates of language impairments and social difficulties. However, no single study has examined different language domains and social functioning in the same sample of children with tri-, tetra-, and…

Lee, Nancy Raitano; Wallace, Gregory L.; Adeyemi, Elizabeth I.; Lopez, Katherine C.; Blumenthal, Jonathan D.; Clasen, Liv S.; Giedd, Jay N.

2012-01-01

310

Experimental Population Genetics of Meiotic Drive Systems. III. Neutralization of Sex-Ratio Distortion in Drosophila through Sex-Chromosome Aneuploidy  

PubMed Central

Laboratory populations of Drosophila melanogaster were challenged by pseudo-Y drive, which mimics true Y-chromosome meiotic drive through the incorporation of Segregation Distorter (SD) in a T(Y;2) complex. This causes extreme sex-ratio distrotion and can ultimately lead to population extinction. Populations normally respond by the gradual accumulation of drive suppressors, and this reduction in strength of distortion allows the sex ratio to move closer to the optimal value of 1:1. One population monitored, however, was rapidly able to neutralize the effects of sex-ratio distortion by the accumulation of sex-chromosome aneuploids (XXY, XYY). This apparently occurs because XX-bearing eggs, produced in relatively high numbers (?4%) by XXY genotypes, become the main population source of females under strong Y-chromosome drive. Computer simulation for a discrete generation model incorporating random mating with differences in fitness and segregation permits several predictions that can be compared to the data. First, sex-chromosome aneuploids should rapidly attain equilibrium, while stabilizing the population at ?60% males. This sex ratio should be roughly independent of the strength of the meiotic drive. Moreover, conditions favoring the accumulation of drive suppressors (e.g., weak distortion, slow population extinction) are insufficient for maintaining aneuploidy, while conditions favoring aneuploidy (e.g., strong distortion, low production of females) lead to population extinction before drive suppressors can accumulate. Thus, the different mechanisms for neutralizing sex-ratio distortion are complementary. In addition, Y drive and sex-chromosome aneuploidy are potentially co-adaptive, since under some conditions neither will survive alone. Finally, these results suggest the possibility that genetic variants promoting sex-chromosome nondisjunction may have a selective advantage in natural populations faced with sex-ratio distortion.

Lyttle, Terrence W.

1981-01-01

311

Sex Chromosome Mosaicism and Hybrid Speciation among Tiger Swallowtail Butterflies  

PubMed Central

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.

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

2011-01-01

312

Sex chromosome mosaicism and hybrid speciation among tiger swallowtail butterflies.  

PubMed

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

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

2011-09-01

313

No Evidence for a Second Evolutionary Stratum during the Early Evolution of Mammalian Sex Chromosomes  

PubMed Central

Mammalian sex chromosomes originated from a pair of autosomes, and homologous genes on the sex chromosomes (gametologs) differentiated through recombination arrest between the chromosomes. It was hypothesized that this differentiation in eutherians took place in a stepwise fashion and left a footprint on the X chromosome termed “evolutionary strata.” The evolutionary stratum hypothesis claims that strata 1 and 2 (which correspond to the first two steps of chromosomal differentiation) were generated in the stem lineage of Theria or before the divergence between eutherians and marsupials. However, this prediction relied solely on the molecular clock hypothesis between pairs of human gametologs, and molecular evolution of marsupial sex chromosomal genes has not yet been investigated. In this study, we analyzed the following 7 pairs of marsupial gametologs, together with their eutherian orthologs that reside in stratum 1 or 2: SOX3/SRY, RBMX/Y, RPS4X/Y, HSFX/Y, XKRX/Y, SMCX/Y (KDM5C/D, JARID1C/D), and UBE1X/Y (UBA1/UBA1Y). Phylogenetic analyses and estimated divergence time of these gametologs reveal that they all differentiated at the same time in the therian ancestor. We have also provided strong evidence for gene conversion that occurred in the 3? region of the eutherian stratum 2 genes (SMCX/Y and UBE1X/Y). The results of the present study show that (1) there is no compelling evidence for the second stratum in the stem lineage of Theria; (2) gene conversion, which may have occurred between SMCX/Y and UBE1X/Y in the eutherian lineage, potentially accounts for their apparently lower degree of overall divergence.

Katsura, Yukako; Satta, Yoko

2012-01-01

314

[Obstetric ultrasound between the 11th and 14th weeks: beyond the screening for chromosomal abnormalities].  

PubMed

This is a traditional (narrative) review with the objective of highlighting the contribution of obstetric ultrasonography (US) between the 11th and 14th week of pregnancy, commonly called first trimester anomaly scan. In addition to being used for the screening of chromosomal anomalies, US can be employed during this period to confirm or determine gestational age, evaluate fetal anatomy, diagnose malformations, screen major structural abnormalities and genetic syndromes, define the prognosis of pregnancy, diagnose and characterize multiple pregnancies, and screen preeclampsia and intrauterine growth restriction. The most important studies about this subject published between 1990 and 2010 in the Cochrane and PubMed libraries were included. The selected studies can be classified with scientific levels I to III. PMID:21625794

Peralta, Cleisson Fábio Andrioli; Barini, Ricardo

2011-01-01

315

Meiotic chromosomes and sex determination mechanism in Thailand and Hawaii isolates of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae).  

PubMed

Angiostrongylus cantonensis, the nematode lungworm of rats, has a XX/X0 sex-determination mechanism. The chromosome constitution consists of 10 autosomes, with 2n=12, XX in the female and 2n=11, X0 in the male. Meiosis-I shows five bivalents and one univalent for the male worm, and six bivalents for the female worm. The chromosome constitution of the Thailand and Hawaii isolates of A. cantonensis is similar to those reported for the taxa from Japan, Egypt and mainland China. PMID:20237450

Eamsobhana, P; Yoolek, A; Yong, H S

2009-12-01

316

Arrested human embryos are more likely to have abnormal chromosomes than developing embryos from women of advanced maternal age  

PubMed Central

Background Aneuploidy is one of the major factors that result in low efficiency in human infertility treatment by in vitro fertilization (IVF). The development of DNA microarray technology allows for aneuploidy screening by analyzing all 23 pairs of chromosomes in human embryos. All chromosome screening for aneuploidy is more accurate than partial chromosome screening, as errors can occur in any chromosome. Currently, chromosome screening for aneuploidy is performed in developing embryos, mainly blastocysts. It has not been performed in arrested embryos and/or compared between developing embryos and arrested embryos from the same IVF cycle. Methods The present study was designed to examine all chromosomes in blastocysts and arrested embryos from the same cycle in patients of advanced maternal ages. Embryos were produced by routine IVF procedures. A total of 90 embryos (45 blastocysts and 45 arrested embryos) from 17 patients were biopsied and analyzed by the Agilent DNA array platform. Results It was found that 50% of the embryos developed to blastocyst stage; however, only 15.6% of the embryos (both blastocyst and arrested) were euploid, and most (84.4%) of the embryos had chromosomal abnormalities. Further analysis indicated that 28.9% of blastocysts were euploid and 71.1% were aneuploid. By contrast, only one (2.2%) arrested embryo was euploid while others (97.8%) were aneuploid. The prevalence of multiple chromosomal abnormalities in the aneuploid embryos was also higher in the arrested embryos than in the blastocysts. Conclusions These results indicate that high proportions of human embryos from patients of advanced maternal age are aneuploid, and the arrested embryos are more likely to have abnormal chromosomes than developing embryos.

2014-01-01

317

A Dominantly Acting Murine Allele of Mcm4 Causes Chromosomal Abnormalities and Promotes Tumorigenesis  

PubMed Central

Here we report the isolation of a murine model for heritable T cell lymphoblastic leukemia/lymphoma (T-ALL) called Spontaneous dominant leukemia (Sdl). Sdl heterozygous mice develop disease with a short latency and high penetrance, while mice homozygous for the mutation die early during embryonic development. Sdl mice exhibit an increase in the frequency of micronucleated reticulocytes, and T-ALLs from Sdl mice harbor small amplifications and deletions, including activating deletions at the Notch1 locus. Using exome sequencing it was determined that Sdl mice harbor a spontaneously acquired mutation in Mcm4 (Mcm4D573H). MCM4 is part of the heterohexameric complex of MCM2–7 that is important for licensing of DNA origins prior to S phase and also serves as the core of the replicative helicase that unwinds DNA at replication forks. Previous studies in murine models have discovered that genetic reductions of MCM complex levels promote tumor formation by causing genomic instability. However, Sdl mice possess normal levels of Mcms, and there is no evidence for loss-of-heterozygosity at the Mcm4 locus in Sdl leukemias. Studies in Saccharomyces cerevisiae indicate that the Sdl mutation produces a biologically inactive helicase. Together, these data support a model in which chromosomal abnormalities in Sdl mice result from the ability of MCM4D573H to incorporate into MCM complexes and render them inactive. Our studies indicate that dominantly acting alleles of MCMs can be compatible with viability but have dramatic oncogenic consequences by causing chromosomal abnormalities.

Bagley, Bruce N.; Keane, Thomas M.; Maklakova, Vilena I.; Marshall, Jonathon G.; Lester, Rachael A.; Cancel, Michelle M.; Paulsen, Alex R.; Bendzick, Laura E.; Been, Raha A.; Kogan, Scott C.; Cormier, Robert T.; Kendziorski, Christina; Adams, David J.; Collier, Lara S.

2012-01-01

318

A novel syndrome of abnormal striatum and congenital cataract: evidence for linkage to chromosomes 11.  

PubMed

We report a consanguineous family of three girls and one boy affected with a novel syndrome involving the lens and the basal ganglia. The phenotype is strikingly similar between affected siblings with cognitive impairment, attention deficit hyperactivity disorder (ADHD), microcephaly, growth retardation, congenital cataract, and dystonia. The magnetic resonance imaging showed unusual pattern of swelling of the caudate heads and thinning of the putamina with severe degree of hypometabolism on the [18F] deoxyglucose positron emission tomography. Furthermore, the clinical assessment provides the evidence that the neurological phenotype is very slowly progressive. We utilized the 10K single-nucleotide polymorphism (SNP) microarray genotyping for linkage analysis. Genome-wide scan indicated a 45.9-Mb region with a 4.2353 logarithm of the odds score on chromosome 11. Affymetrix genome-wide human SNP array 6.0 assay did not show any gross chromosomal abnormality. Targeted sequencing of two candidate genes within the linkage interval (PAX6 and B3GALTL) as well as mtDNA genome sequencing did not reveal any putative mutations. PMID:23181898

Al-Owain, M; Al-Zahrani, J; Al-Bakheet, A; Abudheim, N; Al-Younes, B; Aldhalaan, H; Al-Zaidan, H; Colak, D; Almohaileb, F; Abouzied, M E; Al-Fadhli, F; Meyer, B; Kaya, N

2013-09-01

319

Chromosome abnormalities and sister chromatid exchanges in children with acute intoxication due to inhalation of volatile substances.  

PubMed

Deliberate inhalation of volatile substances is a common and harmful practice among young persons worldwide. Recently, we described chromosome damage in children who chronically inhale volatile agents. Clinical and cytogenetic studies were performed for 15 "sniffing" children (13 boys and 2 girls), the purpose of which was to define the chromosomal effect of the acute intoxication. A significant increase in the rate of chromosome abnormalities and in the frequency of sister chromatid exchanges (SCEs) was found in sniffers vs. controls. The values were also higher in children who were acutely intoxicated than in those who chronically inhaled volatile agents. Clinical, socioeconomic, and cytogenetic findings are also discussed. PMID:2916855

Salamanca-Gómez, F; Hernandez, S; Palma, V; Navarrete, C; Garcia, T; Moreta, G; Buentello, L

1989-01-01

320

In B-cell chronic lymphocytic leukaemia chromosome 17 abnormalities and not trisomy 12 are the single most important cytogenetic abnormalities for the prognosis: A cytogenetic and immunophenotypic study of 480 unselected newly diagnosed patients  

Microsoft Academic Search

Of 560 consecutive, newly diagnosed untreated patients with B CLL submitted for chromosome study, G-banded karyotypes could be obtained in 480 cases (86%). Of these, 345 (72%) had normal karyotypes and 135 (28%) had clonal chromosome abnormalities: trisomy 12 (+12) was found in 40 cases, 20 as +12 alone (+12single), 20 as +12 with additional abnormalities (+12complex). Other frequent findings

C. H. Geisler; P. Philip; B. Egelund Christensen; K. Hou-Jensen; N. Tinggaard Pedersen; O. Myhre Jensen; K. Thorling; E. Andersen; H. S. Birgens; A. Drivsholm; J. Ellegaard; J. K. Larsen; T. Plesner; P. Brown; P. Kragh Andersen; M. Mørk Hansen

1997-01-01

321

Chromosome 3q21 abnormalities associated with hyperactive thrombopoiesis in acute blastic transformation of chronic myeloid leukemia.  

PubMed

Two patients with acute blastic transformation of chronic myeloid leukemia (CML) associated with strikingly elevated platelet counts showed abnormalities of chromosome 3q in addition to the standard Philadelphia (Ph1) chromosome translocation. The first patient had an inversion of chromosome 3 (q21q26) cytologically identical to an inversion 3 previously reported in de novo acute megakaryoblastic leukemia, and the second patient showed a translocation between chromosome 3q and the chromosome 9 homologue not involved in the Ph1 translocation, [t(3;9)(q21;q34)]. Previous studies had incriminated either 3q21 or 3q26 as the locus for a regulatory thrombopoietic gene, but the current study suggests that 3q21 is the relevant site. PMID:3461853

Bernstein, R; Bagg, A; Pinto, M; Lewis, D; Mendelow, B

1986-09-01

322

A chromosomal translocation causing multiple abnormalities including open eyelids at birth and glomerulonephritis.  

PubMed

We have characterized the phenotype of a mouse with a t(2;13) reciprocal translocation induced by chlorambucil. It results in abnormal eyelid formation as well as a series of neurological, physiological, and immunological abnormalities. This mutant has been termed T(2;13)1Fla/+. T(2;13)1Fla/+ mice exhibit open eyelids at birth, a dilute coat color, hyperactivity, and occasional circling and stargazing activity. At 1-6 months, T(2;13)1Fla/+ mice show signs of immune complex-mediated glomerulonephritis and die prematurely. Additionally, double-stranded DNA autoantibodies have been found in sera of T(2;13)1Fla/+ mice. Cytogenetic analysis situated the translocation breakpoint at the proximal end of Chromosome (chr) 2 at band A2, and on Chr 13 at band A4. The mutant phenotype completely correlated with the presence of the translocation. Additional genetic studies have mapped the mutation and translocation breakpoint to Chr 13 between D13Mit16 and D13Mit64, and to Chr 2 proximal to D2Mit5. By fluorescent in situ hybridization (FISH), the position of this mutation/translocation on Chr 13 has been mapped to a region less than 1cM from D13Mit61. PMID:12226706

Guarnieri, Mary H; Cacheiro, Nestor L; Rudofsky, Ulrich H; Montgomery, Jeffry C; Collins, Doris N; Flaherty, Lorraine A

2002-08-01

323

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

PubMed

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

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

324

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

PubMed Central

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.

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

325

Prenatal diagnosis of conotruncal malformations: diagnostic accuracy, outcome, chromosomal abnormalities, and extracardiac anomalies.  

PubMed

The purpose of this study was to determine whether continuing experience in prenatal diagnosis of conotruncal malformations (CTMs) has resulted in improved diagnostic accuracy and outcome. Previous reports have demonstrated particular difficulty with ascertainment of the spatial relationship of the great arteries in patients with CTM. The prognosis for fetuses with CTM was poor. Medical records of 113 consecutive fetuses in whom a CTM (tetralogy of Fallot [TOF], double-outlet right ventricle [DORV], type B aortic arch interruption, transposition of the great arteries [TGA], and persistent truncus arteriosus [TA]) was diagnosed antenatally between 1994 and 2003 were reviewed. The diagnosis of the 91 fetuses with CTM included TOF (n = 32), TGA (n = 29), DORV (n = 22), and TA (n = 8). The great arterial spatial relationship was diagnosed accurately in 84 of the 91 (92%) live-born infants. In the other seven infants with DORV, the great arterial spatial relationship was identified inaccurately. The overall survival to 30 days was 85 of 91 (93%). Twenty-three of 91 (25%) patients had extracardiac anomalies. Genetic diagnosis (amniocentesis) was obtained in 63 of 94 patients; 11 (17%) had chromosomal abnormalities. Maternal glucose tolerance results were obtained in 65 of the 91 patients and were abnormal in 25 of 65 (38%). Prenatal diagnostic accuracy of conotruncal malformations is excellent; the arterial spatial relationship of DORV remains problematic. The populations of fetuses with CTMs who continue to develop to term have an excellent prognosis. PMID:16625498

Sivanandam, Shanthi; Glickstein, Julie S; Printz, Beth F; Allan, Lindsey D; Altmann, Karen; Solowiejczyk, David E; Simpson, Lynn; Perez-Delboy, Annette; Kleinman, Charles S

2006-05-01

326

RNF8 regulates active epigenetic modifications and escape gene activation from inactive sex chromosomes in post-meiotic spermatids  

PubMed Central

Sex chromosomes are uniquely subject to chromosome-wide silencing during male meiosis, and silencing persists into post-meiotic spermatids. Against this background, a select set of sex chromosome-linked genes escapes silencing and is activated in post-meiotic spermatids. Here, we identify a novel mechanism that regulates escape gene activation in an environment of chromosome-wide silencing in murine germ cells. We show that RNF8-dependent ubiquitination of histone H2A during meiosis establishes active epigenetic modifications, including dimethylation of H3K4 on the sex chromosomes. RNF8-dependent active epigenetic memory, defined by dimethylation of H3K4, persists throughout meiotic division. Various active epigenetic modifications are subsequently established on the sex chromosomes in post-meiotic spermatids. These RNF8-dependent modifications include trimethylation of H3K4, histone lysine crotonylation (Kcr), and incorporation of the histone variant H2AFZ. RNF8-dependent epigenetic programming regulates escape gene activation from inactive sex chromosomes in post-meiotic spermatids. Kcr accumulates at transcriptional start sites of sex-linked genes activated in an RNF8-dependent manner, and a chromatin conformational change is associated with RNF8-dependent epigenetic programming. Furthermore, we demonstrate that this RNF8-dependent pathway is distinct from that which recognizes DNA double-strand breaks. Our results establish a novel connection between a DNA damage response factor (RNF8) and epigenetic programming, specifically in establishing active epigenetic modifications and gene activation.

Sin, Ho-Su; Barski, Artem; Zhang, Fan; Kartashov, Andrey V.; Nussenzweig, Andre; Chen, Junjie; Andreassen, Paul R.; Namekawa, Satoshi H.

2012-01-01

327

Aberrant subclavian artery origin in tetralogy of Fallot with pulmonary stenosis is associated with chromosomal or genetic abnormality.  

PubMed

We determined the relationship between aortic arch anatomy in tetralogy of Fallot with pulmonary stenosis and chromosomal or genetic abnormality, by performing analysis of 257 consecutive patients undergoing surgical repair from January, 2003 to March, 2011. Chromosomal or genetic abnormality was identified in 49 of the 257 (19%) patients. These included trisomy 21 (n = 14); chromosome 22q11.2 deletion (n = 16); other chromosomal abnormalities (n = 9); CHARGE (n = 2); Pierre Robin (n = 2); and Kabuki, Alagille, Holt-Oram, Kaufman McKusick, Goldenhar, and PHACE (n = 1 each). Aortic anatomy was classified as left arch with normal branching, right arch with mirror image branching, left arch with aberrant right subclavian artery, or right arch with aberrant left subclavian artery. Associated syndromes occurred in 33 of 203 (16%) patients with left arch and normal branching (odds ratio 1); three of 36 (8%) patients with right arch and mirror image branching (odds ratio 0.4, 95% confidence interval 0.1-1.6); seven of eight (88%) patients with left arch and aberrant right subclavian artery (odds ratio 36, 95% confidence interval 4-302); and six of 10 (60%) patients with right arch and aberrant left subclavian artery (odds ratio 8, 95% confidence interval 2-26). Syndromes were present in 13 of 18 (72%) patients with either right or left aberrant subclavian artery (odds ratio 15, 95% confidence interval 4-45). Syndromes in patients with an aberrant subclavian artery included trisomy 21 (n = 4); chromosome 22q11.2 deletion (n = 5); and Holt-Oram, PHACE, CHARGE, and chromosome 18p deletion (n = 1 each). Aberrant right or left subclavian artery in tetralogy of Fallot with pulmonary stenosis is associated with an increased incidence of chromosomal or genetic abnormality, whereas right aortic arch with mirror image branching is not. The assessment of aortic arch anatomy at prenatal diagnosis can assist counselling. PMID:23732114

Oswal, Nilesh; Christov, Georgi; Sridharan, Shankar; Khambadkone, Sachin; Bull, Catherine; Sullivan, Ian

2014-06-01

328

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

PubMed Central

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.

Meneely, Philip M.; Wood, William B.

1984-01-01

329

Flow cytometric sexing of X- and Y-chromosome-bearing sperm in Sika deer ( Cervus nippon)  

Microsoft Academic Search

The objectives of the study were to determine a practical method of using predetermined sexed semen in Sika deer (Cervus nippon). Semen was collected by electro-ejaculation from two Sika stags and transported to the laboratory and separated into X- and Y-chromosome-bearing sperm after analysis and re-analysis (using a modified high-speed cell sorter), or control (unsorted) semen. Eighty-four Sika hinds were

Q. H. Gao; H. J. Wei; J. Luo; C. M. Han; S. Schoenian; H. Z. Du; Q. S. Lu; J. Qian

2009-01-01

330

Arsenic Exposure, Dermatological Lesions, Hypertension, and Chromosomal Abnormalities among People in a Rural Community of Northwest Iran  

Microsoft Academic Search

Chronic exposure to arsenic compounds is one of the major public-health problems in many developing and some developed countries. The aim of this study was to investigate the effects of chronic exposure to arsenic on dermatological lesions, hypertension, and chromosomal abnormalities among people in a com- munity in the northwest of Iran. The occurrence of dermatological lesions, hypertension, and chromo-

Saeed Dastgiri; Mohammad Mosaferi; Mohammad A. H. Fizi; Nahid Olfati; Shahin Zolali; Nasser Pouladi; Parvin Azarfam

2010-01-01

331

Additional chromosome abnormalities in patients with acute promyelocytic leukemia treated with all-trans retinoic acid and chemotherapy  

Microsoft Academic Search

Background The incidence and prognostic value of additional chromosome abnormalities (ACA) in acute promyelocytic leukemia (APL) is still a controversial matter. Design and Methods We analyze the incidence, characteristics, and outcome of APL patients with and without ACA who have been treated with all-trans retinoic acid (ATRA) plus anthracycline mono- chemotherapy for induction and consolidation. Cytogenetic analysis was available in

José Cervera; Pau Montesinos; Jesús M. Hernández-Rivas; María J. Calasanz; Anna Aventín; María T. Ferro; Elisa Luño; Javier Sánchez; Edo Vellenga; Chelo Rayón; Gustavo Milone; Javier de la Serna; Concha Rivas; José D. González; Mar Tormo; Elena Amutio; Marcos González; Salut Brunet; Bob Lowenberg; Miguel A. Sanz

332

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

PubMed Central

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.

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

333

Nonrandom sex-chromosome association and constitutive heterochromatin in the brush-tailed possum, Trichosurus vulpecula (Marsupialia: Phalangeridae).  

PubMed

Nonrandom associations between the short arms of the sex chromosomes of six Trichosurus vulpecula were studied in 455 cells from the spleen and bone marrow. The association occurs in both sexes and was found to be independent of age. There was, however, a significant difference in the degree of association between the two tissues studied. Regions of constitutive heterochromatin were found to be located in the short arms of the X and Y chromosomes by using a C-banding technique. Nucleolar organizers were detected in the middle of the long arm of the X chromosome and in the short arm of the Y chromosome by N-banding. These results indicate that the nonrandom association of the sex chromosomes may reflect an association between heterochromatin regions during interphase of the cell cycle. PMID:862434

Murray, J D

1977-01-01

334

Clinical Utility of Array Comparative Genomic Hybridization for Detection of Chromosomal Abnormalities in Pediatric Acute Lymphoblastic Leukemia  

PubMed Central

Background Accurate detection of recurrent chromosomal abnormalities is critical to assign patients to risk-based therapeutic regimens for pediatric acute lymphoblastic leukemia (ALL). Procedure We investigated the utility of array comparative genomic hybridization (aCGH) for detection of chromosomal abnormalities compared to standard clinical evaluation with karyotype and fluorescent in-situ hybridization (FISH). Fifty pediatric ALL diagnostic bone marrows were analyzed by bacterial artificial chromosome (BAC) array, and findings compared to standard clinical evaluation. Results Sensitivity of aCGH was 79% to detect karyotypic findings other than balanced translocations, which cannot be detected by aCGH because they involve no copy number change. aCGH also missed abnormalities occurring in subclones constituting less than 25% of cells. aCGH detected 44 additional abnormalities undetected or misidentified by karyotype, 21 subsequently validated by FISH, including abnormalities in 4 of 10 cases with uninformative cytogenetics. aCGH detected concurrent terminal deletions of both 9p and 20q in three cases, in two of which the 20q deletion was undetected by karyotype. A narrow region of loss at 7p21 was detected in two cases. Conclusions An array with increased BAC density over regions important in ALL, combined with PCR for fusion products of balanced translocations, could minimize labor- and time-intensive cytogenetic assays and provide key prognostic information in the approximately 35% of cases with uninformative cytogenetics.

Rabin, Karen R.; Man, Tsz-Kwong; Yu, Alexander; Folsom, Matthew R.; Zhao, Yi-Jue; Rao, Pulivarthi H.; Plon, Sharon E.; Naeem, Rizwan C.

2014-01-01

335

Evidence that sex chromosome asynapsis, rather than excess Y gene dosage, is responsible for the meiotic impairment of XYY mice.  

PubMed

There is extensive evidence for the existence of a meiotic checkpoint that acts to eliminate spermatocytes that fail to achieve full sex chromosome synapsis at the pachytene stage of the first meiotic prophase. XYY mice are nearly always sterile, with clear signs of meiotic impairment, and sex chromosome asynapsis has been proposed to underlie this impairment. However, a study of XYY*(X) mice (mice having three sex chromosomes but only a single dose of Y genes) revealed that these mice are fertile, and thus implicated Y gene dosage as a major factor in the sterility of XYY mice. To address this question further, sex chromosome synapsis and spermatogenic proficiency were compared between XYY*(X) and XYY mice generated in the same litters. This established that differences in spermatogenic proficiency within and between the two genotypes correlated with the frequency of radial trivalent formation (full sex chromosome synapsis); XYY*(X) males, as a group, had double the radial trivalent frequency of XYY males. This observation provides strong support for the view that sex chromosome asynapsis (or some consequence thereof), rather than Y gene dosage, is the major factor leading to the meiotic impairment of XYY mice. PMID:10894933

Rodriguez, T A; Burgoyne, P S

2000-01-01

336

Two sex-chromosome-linked microsatellite loci show geographic variance among North American Ostrinia nubilalis  

PubMed Central

PCR-based O. nubilalis population and pedigree analysis indicated female specificity of a (GAAAAT)n microsatellite, and male specificity of a CAYCARCGTCACTAA repeat unit marker. These loci were respectively named Ostrinia nubilalis W-chromosome 1 (ONW1) and O. nubilalis Z-chromosome 1 (ONZ1). Intact repeats of three, four, or five GAAAAT units are present among ONW1 alleles, and biallelic variation exists at the ONZ1 locus. Screening of 493 male at ONZ1 and 448 heterogametic females at ONZ1 and ONW1 loci from eleven North American sample sites was used to construct genotypic data. Analysis of molecular variance (AMOVA) and F-statistics indicated no female haplotype or male ONZ1 allele frequency differentiation between voltinism ecotypes. Four subpopulations from northern latitudes, Minnesota and South Dakota, showed the absence of a single female haplotype, a significant deviation of ONZ1 data from Hardy-Weinberg expectation, and low-level geographic divergence from other subpopulations. Low ONZ1 and ONW1 allele diversity could be attributed either to large repeat unit sizes, low repeat number, reduced effective population (Ne) size of sex chromosomes, or the result of recent O. nubilalis introduction and population expansion, but likely could not be due to inbreeding. These sequences have been deposited in GenBank AF442958, and AY102618 to AY102620. Abbreviation: ONW1 Ostrinia nubilalis W-chromosome marker number 1 ONZ1 Ostrinia nubilalis Z-chromosome marker number 1

Coates, Brad S.; Hellmich, Richard L.

2003-01-01

337

Sex-specific telomere length profiles and age-dependent erosion dynamics of individual chromosome arms in humans  

Microsoft Academic Search

During aging, telomeres are gradually shortened, eventually leading to cellular senescence. By T\\/C-FISH (telomere\\/centromere-FISH), we investigated human telomere length differences on single chromosome arms of 205 individuals in different age groups and sexes. For all chromosome arms, we found a linear correlation between telomere length and donor age. Generally, males had shorter telomeres and higher attrition rates. Every chromosome arm

S. Mayer; S. Brüderlein; S. Perner; I. Waibel; A. Holdenried; N. Ciloglu; C. Hasel; T. Mattfeldt; K. V. Nielsen; P. Möller

2006-01-01

338

The localization of “ordinary” sex-linked genes in section 20 of the polytene X chromosome of Drosophila melanogaster  

Microsoft Academic Search

A cytogenetic procedure is described whereby a combination of polytene chromosome analysis and complementation mapping has permitted the unequivocal localization of “ordinary” sex-linked genes (those not covered by the Y-chromosome) in Section 20, the most proximal region of Bridges' (1938) map of the polytene X-chromosome. Thus far, eleven functional units in Section 20 distal to the bobbed locus, but none

Abraham Schalet; George Lefevre

1973-01-01

339

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

SciTech Connect

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.

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

1982-11-26

340

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

Microsoft Academic Search

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

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

2009-01-01

341

Construction of Papaya Male and Female BAC Libraries and Application in Physical Mapping of the Sex Chromosomes  

PubMed Central

Papaya is a major fruit crop in the tropics and has recently evolved sex chromosomes. Towards sequencing the papaya sex chromosomes, two bacterial artificial chromosome (BAC) libraries were constructed from papaya male and female genomic DNA. The female BAC library was constructed using restriction enzyme BstY I and consists of 36,864 clones with an average insert size of 104?kb, providing 10.3x genome equivalents. The male BAC library was constructed using restriction enzyme EcoR I and consists of 55,296 clones with an average insert size of 101?kb, providing 15.0x genome equivalents. The male BAC library was used in constructing the physical map of the male-specific region of the male Y chromosome (MSY) and in filling gaps and extending the physical map of the hermaphrodite-specific region of the Yh chromosome (HSY) and the X chromosome physical map. The female BAC library was used to extend the X physical map gap. The MSY, HSY, and X physical maps offer a unique opportunity to study chromosomal rearrangements, Y chromosome degeneration, and dosage compensation of the papaya nascent sex chromosomes.

Gschwend, Andrea R.; Yu, Qingyi; Moore, Paul; Saski, Christopher; Chen, Cuixia; Wang, Jianping; Na, Jong-Kuk; Ming, Ray

2011-01-01

342

Possible influences on the expression of X chromosome-linked dystrophin abnormalities by heterozygosity for autosomal recessive Fukuyama congenital muscular dystrophy.  

PubMed Central

Abnormalities of dystrophin, a cytoskeletal protein of muscle and nerve, are generally considered specific for Duchenne and Becker muscular dystrophy. However, several patients have recently been identified with dystrophin deficiency who, before dystrophin testing, were considered to have Fukuyama congenital muscular dystrophy (FCMD) on the basis of clinical findings. Epidemiologic data suggest that only 1/3500 males with autosomal recessive FCMD should have abnormal dystrophin. To explain the observation of 3/23 FCMD males with abnormal dystrophin, we propose that dystrophin and the FCMD gene product interact and that the earlier onset and greater severity of these patients' phenotype (relative to Duchenne muscular dystrophy) are due to their being heterozygous for the FCMD mutation in addition to being hemizygous for Duchenne muscular dystrophy, a genotype that is predicted to occur in 1/175,000 Japanese males. This model may help explain the genetic basis for some of the clinical and pathological variability seen among patients with FCMD, and it has potential implications for understanding the inheritance of other autosomal recessive disorders in general. For example, sex ratios for rare autosomal recessive disorders caused by mutations in proteins that interact with X chromosome-linked gene products may display predictable deviation from 1:1. Images

Beggs, A H; Neumann, P E; Arahata, K; Arikawa, E; Nonaka, I; Anderson, M S; Kunkel, L M

1992-01-01

343

Studies on Brahma rasayana in male swiss albino mice: Chromosomal aberrations and sperm abnormalities  

PubMed Central

Ayurveda, the Indian holistic healthcare system encompasses traditional medicines with a principle of creating harmony and maintaining balance within the natural rhythms of the body. Rasayana is one of the branches of Ayurveda frequently used as rejuvenant therapy to overcome many discomforts and prevent diseases. It has been reported that rasayanas have immunomodulatory, antioxidant and antitumor functions. However, the genotoxic potential of many rasayanas remains to be evaluated. The present study was undertaken to assess the role of Brahma rasayana(BR) on genotoxicity in vivo in a mouse test system. The older mice (9 months) were orally fed with rasayana for 8 weeks. The treated groups showed no signs of dose-dependent toxicity at the dosage levels tested. The body weight loss/gain and feed consumption were unaffected at tested doses. Furthermore, sperm abnormalities and chromosomal aberrations were insignificant in the treatment group when compared to controls. However, there was a marginal increase in sperm count in the BR treated animals. These findings clearly indicate that there are no observed adverse genotoxic effects elicited by BR in experimental animals such as mice.

Guruprasad, K. P.; Mascarenhas, Roshan; Gopinath, P. M.; Satyamoorthy, K.

2010-01-01

344

Partial paternal uniparental disomy of chromosome 6 in an infant with neonatal diabetes, macroglossia, and craniofacial abnormalities.  

PubMed

Neonatal diabetes, which can be transient or permanent, is defined as hyperglycemia that presents within the first month of life and requires insulin therapy. Transient neonatal diabetes mellitus has been associated with abnormalities of the paternally inherited copy of chromosome 6, including duplications of a portion of the long arm of chromosome 6 and uniparental disomy, implicating overexpression of an imprinted gene in this disorder. To date, all patients with transient neonatal diabetes mellitus and uniparental disomy have had complete paternal isodisomy. We describe a patient with neonatal diabetes, macroglossia, and craniofacial abnormalities, with partial paternal uniparental disomy of chromosome 6 involving the distal portion of 6q, from 6q24-qter. This observation demonstrates that mitotic recombination of chromosome 6 can also give rise to uniparental disomy and neonatal diabetes, a situation similar to that observed in Beckwith-Wiedemann syndrome, another imprinted disorder. This finding has clinical implications, since somatic mosaicism for uniparental disomy of chromosome 6 should also be considered in patients with transient neonatal diabetes mellitus. PMID:11038325

Das, S; Lese, C M; Song, M; Jensen, J L; Wells, L A; Barnoski, B L; Roseberry, J A; Camacho, J M; Ledbetter, D H; Schnur, R E

2000-12-01

345

Partial Paternal Uniparental Disomy of Chromosome 6 in an Infant with Neonatal Diabetes, Macroglossia, and Craniofacial Abnormalities  

PubMed Central

Neonatal diabetes, which can be transient or permanent, is defined as hyperglycemia that presents within the first month of life and requires insulin therapy. Transient neonatal diabetes mellitus has been associated with abnormalities of the paternally inherited copy of chromosome 6, including duplications of a portion of the long arm of chromosome 6 and uniparental disomy, implicating overexpression of an imprinted gene in this disorder. To date, all patients with transient neonatal diabetes mellitus and uniparental disomy have had complete paternal isodisomy. We describe a patient with neonatal diabetes, macroglossia, and craniofacial abnormalities, with partial paternal uniparental disomy of chromosome 6 involving the distal portion of 6q, from 6q24-qter. This observation demonstrates that mitotic recombination of chromosome 6 can also give rise to uniparental disomy and neonatal diabetes, a situation similar to that observed in Beckwith-Wiedemann syndrome, another imprinted disorder. This finding has clinical implications, since somatic mosaicism for uniparental disomy of chromosome 6 should also be considered in patients with transient neonatal diabetes mellitus.

Das, S.; Lese, C. M.; Song, M.; Jensen, J. L.; Wells, L. A.; Barnoski, B. L.; Roseberry, J. A.; Camacho, J. M.; Ledbetter, D. H.; Schnur, R. E.

2000-01-01

346

Structural chromosomal abnormalities detected during CVS analysis and their role in the prenatal ascertainment of cryptic subtelomeric rearrangements.  

PubMed

Mosaic structural chromosomal abnormalities observed along the trophoblast-mesenchyme-fetal axis, although rare, pose a difficult problem for their prognostic interpretation in prenatal diagnosis. Additional issues are raised by the presence of mosaic imbalances of the same chromosome showing different sizes in the different tissues, that is, deletions and duplications in the cytotrophoblast and mesenchyme of chorionic villi (CV). Some of these cytogenetic rearrangements originate from the post-zygotic breakage of a dicentric chromosome or of the product of its first anaphasic breakage. Selection of the most viable cell line may result in confined placental mosaicism of the most severe imbalance, favoring the presence of the cell lines with the mildest duplications or deletions in the fetal tissues. We document three cases of ambiguous results in CV analysis due to the presence of different cell lines involving structural rearrangements of the same chromosome which were represented differently in the trophoblast and the mesenchyme. Observation by conventional karyotype of a grossly rearranged chromosome in one of the CV preparations (direct or culture) was crucial to call attention to the involved chromosomal region in other tissues (villi or amniotic fluid), allowing the prenatal diagnosis through molecular cytogenetic methods of subtelomeric rearrangements [del(7)(q36qter); del(11)(q25qter); del(20)(p13pter)]. This would have surely been undiagnosed with the routine banding technique. In conclusion, the possibility to diagnose complex abnormalities leading to cryptic subtelomeric rearrangements, together with a better knowledge of the initial/intermediate products leading to the final abnormal cryptic deletion should be added to the advantages of the CV sampling technique. PMID:23922197

Pittalis, Maria Carla; Mattarozzi, Angela; Menozzi, Cristina; Malacarne, Michela; Baccolini, Ilaria; Farina, Antonio; Pompilii, Eva; Magini, Pamela; Percesepe, Antonio

2013-10-01

347

Cytogenetic studies in Eigenmannia virescens (Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the Eigenmannia genus  

PubMed Central

Background Cytogenetic studies were carried out on samples of Eigenmannia virescens (Sternopygidae, Gymnotiformes) obtained from four river systems of the Eastern Amazon region (Para, Brazil). Results All four populations had 2n = 38, with ZZ/ZW sex chromosomes (Z, acrocentric; W, submetacentric). Constitutive heterochromatin (CH) was found at the centromeric regions of all chromosomes. The W chromosome had a heterochromatic block in the proximal region of the short arm; this CH was positive for DAPI staining, indicating that it is rich in A-T base pairs. The nucleolar organizer region (NOR) was localized to the short arm of chromosome pair 15; this result was confirmed by fluorescent in situ hybridization (FISH) with human 45S rDNA, and CMA3 staining indicated that the region is G-C rich. FISH with telomeric probes did not show any evidence of interstitial telomeric sequences (ITS). Conclusion Previous studies have shown that the species Eigenmannia sp. 2 and E. virescens have differentiated sex chromosomes, and diverse sex chromosome systems have been described for E. virescens specimens obtained from different Brazilian rivers. A comparative analysis of the present data and prior reports suggests that the sex chromosomes of Eigenmannia may have arisen independently in the different populations.

2009-01-01

348

Moderate Ovarian Stimulation Does Not Increase the Incidence of Human Embryo Chromosomal Abnormalities in in Vitro Fertilization Cycles  

PubMed Central

Context: A high chromosomal abnormalities rate has been observed in human embryos derived from in vitro fertilization (IVF) treatments. The real incidence in natural cycles has been poorly studied, so whether this frequency may be induced by external factors, such as use of gonadotropins for ovarian stimulation, remains unknown. Design: We conducted a prospective cohort study in a University-affiliated private infertility clinic with a comparison between unstimulated and stimulated ovarian cycles in the same women. Preimplantation genetic screening by fluorescence in situ hybridization was performed in all viable d 3 embryos. Objective: The primary objective was to compare the incidence of embryo chromosomal abnormalities in an unstimulated cycle and in an ulterior moderate ovarian stimulated cycle. Secondary outcome measures were embryo quality, blastocyst rate of biopsied embryos, number of normal blastocysts per donor, type of chromosomal abnormalities, and clinical outcome. Results: One hundred eighty-five oocyte donors were initially recruited for the unstimulated cycle, and preimplantation genetic screening could be performed in 51 of them, showing 35.3% of embryo chromosomal abnormalities. Forty-six of them later completed a stimulated cycle. The sperm donor sample was the same for both cycles. The proportion of embryos displaying abnormalities in the unstimulated cycle was 34.8% (16 of 46), whereas it was 40.6% (123 of 303) in the stimulated cycle with risk difference = 5.8 [95% confidence interval (CI) = ?20.6–9.0], and relative risk = 1.17 (95% CI = 0.77–1.77) (P = 0.45). When an intrasubject comparison was made, the abnormalities rate was 34.8% (95% CI = 20.5–49.1) in the unstimulated cycle and 38.2% (95% CI = 30.5–45.8) in the stimulated cycle [risk difference = 3.4 (95% CI = ?17.9–11.2); P = 0.64]. No differences were observed for embryo quality and type of chromosomal abnormalities. Conclusions: Moderate ovarian stimulation in young normo-ovulatory women does not significantly increase the embryo aneuploidies rate in in vitro fertilization-derived human embryos as compared with an unstimulated cycle. Whether these results can be extrapolated to infertile patients is still unknown.

Bosch, Ernesto; Alama, Pilar; Rubio, Carmen; Rodrigo, Lorena; Pellicer, Antonio

2012-01-01

349

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

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.

2011-01-01

350

Abnormalities in spontaneous abortions detected by G-banding and chromosomal microarray analysis (CMA) at a national reference laboratory  

PubMed Central

Background Cytogenetic evaluation of products of conception (POC) for chromosomal abnormalities is central to determining the cause of pregnancy loss. We compared the test success rates in various specimen types and the frequencies of chromosomal abnormalities detected by G-banding analysis with those found by Oligo-SNP chromosomal microarray analysis (CMA). We evaluated the benefit of CMA testing in cases of failed culture growth. Methods Conventional cytogenetic results of 5457 consecutive POC specimens were reviewed and categorized as placental villi, fetal parts, and unspecified POC tissue. The CMA was performed on 268 cases. Of those, 32 cases had concurrent G-banding results. The remaining 236 cases included 107 cases with culture failure and 129 cases evaluated by CMA alone. Results The overall POC culture success rate was 75%, with the lowest for fetal parts (37.4%) and the highest for placental villi (81%). The abnormality rate was 58% for placental villi, but only 25% for fetal parts. Of the abnormalities detected, the most common were aneuploidies, including trisomy 16, triploidy, monosomy X, trisomy 22, trisomy 21 and trisomy 15, while the least encountered aneuploidies were trisomy 1, trisomy 19 and monosomies (except monosomy 21). Overall, POC specimens studied by CMA were successful in 89.6% of cases and yielded a 44.6% abnormality rate. Conclusions Placental villi yielded higher rates of culture success and a higher percentage of abnormal karyotypes than did other specimen types. The Oligo-SNP CMA method has demonstrated a viable alternative to the G-banding method in view of its advantages in detection of submicroscopic genomic aberrations, shorter turnaround time due to elimination of time required for culture and a higher test success rate.

2014-01-01

351

Expansion of the Pseudo-autosomal Region and Ongoing Recombination Suppression in the Silene latifolia Sex Chromosomes  

PubMed Central

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.

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

2013-01-01

352

Evolutionary history of novel genes on the tammar wallaby Y chromosome: Implications for sex chromosome evolution.  

PubMed

We report here the isolation and sequencing of 10 Y-specific tammar wallaby (Macropus eugenii) BAC clones, revealing five hitherto undescribed tammar wallaby Y genes (in addition to the five genes already described) and several pseudogenes. Some genes on the wallaby Y display testis-specific expression, but most have low widespread expression. All have partners on the tammar X, along with homologs on the human X. Nonsynonymous and synonymous substitution ratios for nine of the tammar XY gene pairs indicate that they are each under purifying selection. All 10 were also identified as being on the Y in Tasmanian devil (Sarcophilus harrisii; a distantly related Australian marsupial); however, seven have been lost from the human Y. Maximum likelihood phylogenetic analyses of the wallaby YX genes, with respective homologs from other vertebrate representatives, revealed that three marsupial Y genes (HCFC1X/Y, MECP2X/Y, and HUWE1X/Y) were members of the ancestral therian pseudoautosomal region (PAR) at the time of the marsupial/eutherian split; three XY pairs (SOX3/SRY, RBMX/Y, and ATRX/Y) were isolated from each other before the marsupial/eutherian split, and the remaining three (RPL10X/Y, PHF6X/Y, and UBA1/UBE1Y) have a more complex evolutionary history. Thus, the small marsupial Y chromosome is surprisingly rich in ancient genes that are retained in at least Australian marsupials and evolved from testis-brain expressed genes on the X. PMID:22128133

Murtagh, Veronica J; O'Meally, Denis; Sankovic, Natasha; Delbridge, Margaret L; Kuroki, Yoko; Boore, Jeffrey L; Toyoda, Atsushi; Jordan, Kristen S; Pask, Andrew J; Renfree, Marilyn B; Fujiyama, Asao; Graves, Jennifer A Marshall; Waters, Paul D

2012-03-01

353

Evidence that meiotic sex chromosome inactivation is essential for male fertility.  

PubMed

The mammalian X and Y chromosomes share little homology and are largely unsynapsed during normal meiosis. This asynapsis triggers inactivation of X- and Y-linked genes, or meiotic sex chromosome inactivation (MSCI). Whether MSCI is essential for male meiosis is unclear. Pachytene arrest and apoptosis is observed in mouse mutants in which MSCI fails, e.g., Brca1(-/-), H2afx(-/-), Sycp1(-/-), and Msh5(-/-). However, these also harbor defects in synapsis and/or recombination and as such may activate a putative pachytene checkpoint. Here we present evidence that MSCI failure is sufficient to cause pachytene arrest. XYY males exhibit Y-Y synapsis and Y chromosomal escape from MSCI without accompanying synapsis/recombination defects. We find that XYY males, like synapsis/recombination mutants, display pachytene arrest and that this can be circumvented by preventing Y-Y synapsis and associated Y gene expression. Pachytene expression of individual Y genes inserted as transgenes on autosomes shows that expression of the Zfy 1/2 paralogs in XY males is sufficient to phenocopy the pachytene arrest phenotype; insertion of Zfy 1/2 on the X chromosome where they are subject to MSCI prevents this response. Our findings show that MSCI is essential for male meiosis and, as such, provide insight into the differential severity of meiotic mutations' effects on male and female meiosis. PMID:21093264

Royo, Hélène; Polikiewicz, Grzegorz; Mahadevaiah, Shantha K; Prosser, Haydn; Mitchell, Mike; Bradley, Allan; de Rooij, Dirk G; Burgoyne, Paul S; Turner, James M A

2010-12-01

354

Male infertility in China: laboratory finding for AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China  

Microsoft Academic Search

Purposes  To investigate the frequencies of AZF microdeletions and chromosomal abnormalities in infertile men from Northeastern China.\\u000a Moreover, to compare the prevalence of these abnormalities with other countries and regions in the world.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  305 infertile men were enrolled. A complete semen analysis and reproductive hormones were measured according to standard methods.\\u000a Multiplex polymerase chain reaction (PCR) amplification using nine specific sequence-tagged

Rui-Xue Wang; Chao Fu; Ya-Ping Yang; Rong-Rong Han; Yuan Dong; Ru-Lin Dai; Rui-Zhi Liu

2010-01-01

355

Deregulated Sex Chromosome Gene Expression with Male Germ Cell-Specific Loss of Dicer1  

PubMed Central

MicroRNAs (miRNAs) are a class of endogenous, non-coding RNAs that mediate post-transcriptional gene silencing by inhibiting mRNA translation and promoting mRNA decay. DICER1, an RNase III endonuclease encoded by Dicer1, is required for processing short 21–22 nucleotide miRNAs from longer double-stranded RNA precursors. Here, we investigate the loss of Dicer1 in mouse postnatal male germ cells to determine how disruptions in the miRNA biogenesis pathway may contribute to infertility. Reduced levels of Dicer1 transcripts and DICER1 were confirmed in germ cell knock-out (GCKO) testes by postnatal day 18 (P18). Compared to wild-type (WT) at 8 weeks, GCKO males had no change in body weight; yet showed significant reductions in testis mass and sperm number. Histology and fertility tests confirmed spermatogenic failure in GCKO males. Array analyses at P18 showed that in comparison to WT testes, 75% of miRNA genes and 37% of protein coding genes were differentially expressed in GCKO testes. Among these, 96% of miRNA genes were significantly down-regulated, while 4% miRNA genes were overexpressed. Interestingly, we observed preferential overexpression of genes encoded on the sex chromosomes in GCKO testes, including more than 80% of previously identified targets of meiotic sex chromosome inactivation (MSCI). Compared to WT, GCKO mice showed higher percentages of germ cells at early meiotic stages (leptotene and zygotene) but lower percentages at later stages (pachytene, diplotene and metaphase I) providing evidence that deletion of Dicer1 leads to disruptions in meiotic progression. Therefore, deleting Dicer1 in early postnatal germ cells resulted in deregulation of transcripts encoded by genes on the sex chromosomes, impaired meiotic progression and led to spermatogenic failure and infertility.

Snyder, Elizabeth; Buaas, F. William; Gu, Tongjun; Stearns, Timothy M.; Sharma, Manju; Murchison, Elizabeth P.; Puente, Gabriella C.; Braun, Robert E.

2012-01-01

356

A sex-determining region on the Y chromosome controls the sex-reversal ratio in interspecific hybrids between Oryzias curvinotus females and Oryzias latipes males  

Microsoft Academic Search

Oryzias latipes and Oryzias curvinotus are closely related medaka species that have the common sex-determining gene, DMY, on their homologous Y chromosomes. We previously reported that sex-reversed XY females were produced in hybrids between O. curvinotus females and O. latipes males (Hd-rR inbred strain). In this study we used HNI inbred strain males of O. latipes for mating with O.

M Kato; Y Takehana; M Sakaizumi; S Hamaguchi

2010-01-01

357

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

NASA Astrophysics Data System (ADS)

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.

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

2010-07-01

358

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

PubMed Central

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.

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

2010-01-01

359

[Analysis on genetic defects of patients with azoospermia and severe oligospermia--report of 2 novel abnormal karyotypes].  

PubMed

G banding karyotype analysis of peripheral lymphocytes in 217 patients with azoospermia or severe oligospermia were performed and the Y-chromosome AZFc region from 7 cases with Y chromosome abnormality was amplified by polymerase chain reaction (PCR). Out of 187 cases with azoospermia, 77 patients or 41.18% had chromosome abnormalities, including number and structural aberrations, heteromorphic chromosomes (Y chromosome heteromorphisms and pericentric inversion of chromosome 9) and 46, XX sex reversal. Two novel abnormal karyotypes were found: 46, XY, t(6; 14)(p21; p13) and 46, XY, t(8; 12)(p21; q24). Out of 30 patients with severe oligospermia, 4 had chromosome abnormalities, including structural aberration and 46, XX sex reversal. Therefore, aberration of the sex chromosome causes the most serious spermatogenic failure and certain breakpoints in the autosomes may also affect spermatogenesis. The deletion of AZFc also affects spermatogenesis. PMID:16818424

Zhang, Xiao-Yun; Li, Yong-Quan; Zheng, Ke-Qin; Zhou, Ru-Bin; Chen, Xiao-Ping; Liao, Xia

2006-06-01

360

Analysis of chromosome abnormalities by comparative genomic hybridization in malignant peripheral primitive neuroectodermal tumor of the ovary  

Microsoft Academic Search

Objective. Malignant primitive neuroectodermal tumor (PNET) originating from the ovary rather than from the central nervous system is extremely rare. The aim of this study is to demonstrate the chromosomal abnormalities in a case of peripheral primitive neuroectodermal tumor (PPNET) arising from the ovary of a girl.Methods. The 13-year-old girl underwent exploratory laparotomy because of a huge pelvic tumor in

Song-Nan Chow; Ming-Chieh Lin; Jenta Shen; Sheng Wang; Yiin-Jeng Jong; Chin-Hsiang Chien

2004-01-01

361

Quantitative analysis of chromosomal CGH in human breast tumors associates copy number abnormalities with p53 status and patient survival  

Microsoft Academic Search

We present a general method for rigorously identifying correlations between variations in large-scale molecular profiles and outcomes and apply it to chromosomal comparative genomic hybridization data from a set of 52 breast tumors. We identify two loci where copy number abnormalities are correlated with poor survival outcome (gain at 8q24 and loss at 9q13). We also identify a relationship between

Ajay N. Jain; Koei Chin; Anne-Lise Børresen-Dale; Bjorn K. Erikstein; Per Eystein Lonning; Rolf Kaaresen; Joe W. Gray

2001-01-01

362

Global search for chromosomal abnormalities in infiltrating ductal carcinoma of the breast using array-comparative genomic hybridization  

Microsoft Academic Search

Array-comparative genomic hybridization (a-CGH) is a molecular cytogenetic technique for detection of multiple chromosomal abnormalities in genomic DNA samples. Using an a-CGH with 287 probes, we examined 14 cases of breast infiltrating ductal carcinoma (IDCA) that had previously been classified by fluorescent in situ hybridization (FISH) as either human epidermal growth factor receptor-2 positive (HER2+) or HER2? and analyzed the

Stella B. Somiari; Craig D. Shriver; Jing He; Kishan Parikh; Rick Jordan; Jeffrey Hooke; Hai Hu; Brenda Deyarmin; Susan Lubert; Lisa Malicki; Caroline Heckman; Richard I. Somiari

2004-01-01

363

Additional chromosome abnormalities in patients with acute promyelocytic leukemia treated with all-trans retinoic acid and chemotherapy  

Microsoft Academic Search

Background: Acute promyelocytic leukemia is a subtype of acute myeloid leukemia characterized by the t(15;17). The incidence and prognostic significance of additional chromosomal abnormalities in acute promyelocytic leukemia is still a controversial matter. Design and Methods: Based on cytogenetic data available for 495 patients with acute promyelocytic leukemia enrolled in two consecutive PETHEMA trials (LPA96 and LPA99), we analyzed the

J. Cervera; P. Montesinos; J. M. Hernandez-Rivas; M. J. Calasanz; A. Aventín; M. T. Ferro; E. Luño; J. Sánchez; E. Vellenga; C. Rayón; G. Milone; J. de la Serna; C. Rivas; J. D. González; M. Tormo; E. Amutio; S. Brunet; B. Löwenberg; M. A. Sanz

2010-01-01

364

Multiple Nuclear Gene Phylogenetic Analysis of the Evolution of Dioecy and Sex Chromosomes in the Genus Silene  

PubMed Central

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.

Marais, Gabriel A. B.; Forrest, Alan; Kamau, Esther; Kafer, Jos; Daubin, Vincent; Charlesworth, Deborah

2011-01-01

365

Congenital abnormality effect of methamphetamine on histological, cellular and chromosomal defects in fetal mice  

PubMed Central

Background: Methamphetamine (MA) is a potent psychomotor stimulant with high abuse and addictive potential. MA is a neurotoxic drug which is widely abused by females of childbearing age, raising serious public health concerns in terms of exposure of the fetus to the drug. Neurotoxic effects of MA on adult are well known, such as dopaminergic nerve terminal degeneration and cell death in regions of brain in some doses. Objective: In the present study, we examined effect of prenatal MA exposure on mouse fetuses. Materials and Methods: In this study, forty 8-12 week-old NMRI female mice were used which were mated with male mice in serial days. When sperm plug was observed it was designated as gestational day (GD) 0. Pregnant mice were individually housed in plastic cages. Pregnant mice were divided into four groups: in first group 10 mg/kg /day MA, in second group 5 mg/kg /day MA and in third group saline were injected subcutaneously from GD 6 to GD 14, corresponding to organogenesis period, while fourth or control group were without injection. On GD 14 fetuses were removed and accomplished chromosome preparation from fetal liver. Then fetal were fixed in formalin for brain hematoxilin and eosine staining and TUNEL assay. Results: We observed morphological abnormality including exencephal fetus in 5mg/kg MA group and premature fetuses in 10 mg/kg MA group. Also brain histological study showed subarachnoid hemorrhage in fetal brain in both experimental groups. Fetal liver karyotyping analysis was normal in fetuses of all groups and TUNEL assay in fetal striatum did not show significant difference in number of apoptotic cells between groups. Conclusion: From our results, it could be concluded that chronic abuse of MA by pregnant females during organogenesis period can cause teratogenic effect and brain hemorrage in fetus.

Mirjalili, Tahereh; Kalantar, Seyed Mehdi; Shams Lahijani, Maryam; Sheikhha, Mohamad Hasan; Talebi, Alireza

2013-01-01

366

XY sex chromosome complement, compared with XX, in the CNS confers greater neurodegeneration during experimental autoimmune encephalomyelitis  

PubMed Central

Women are more susceptible to multiple sclerosis (MS) and have more robust immune responses than men. However, men with MS tend to demonstrate a more progressive disease course than women, suggesting a disconnect between the severity of an immune attack and the CNS response to a given immune attack. We have previously shown in an MS model, experimental autoimmune encephalomyelitis, that autoantigen-sensitized XX lymph node cells, compared with XY, are more encephalitogenic. These studies demonstrated an effect of sex chromosomes in the induction of immune responses, but did not address a potential role of sex chromosomes in the CNS response to immune-mediated injury. Here, we examined this possibility using XX versus XY bone marrow chimeras reconstituted with a common immune system of one sex chromosomal type. We found that experimental autoimmune encephalomyelitis mice with an XY sex chromosome complement in the CNS, compared with XX, demonstrated greater clinical disease severity with more neuropathology in the spinal cord, cerebellum, and cerebral cortex. A candidate gene on the X chromosome, toll-like receptor 7, was then examined. Toll-like receptor 7 expression in cortical neurons was higher in mice with XY compared with mice with XX CNS, consistent with the known neurodegenerative role for toll-like receptor 7 in neurons. These results suggest that sex chromosome effects on neurodegeneration in the CNS run counter to effects on immune responses, and may bear relevance to the clinical enigma of greater MS susceptibility in women but faster disability progression in men. This is a demonstration of a direct effect of sex chromosome complement on neurodegeneration in a neurological disease.

Du, Sienmi; Itoh, Noriko; Askarinam, Sahar; Hill, Haley; Arnold, Arthur P.; Voskuhl, Rhonda R.

2014-01-01

367

The implications of myelodysplastic syndrome - associated chromosomal abnormalities in the development of graft-versus-host disease.  

PubMed

There is a growing body of evidences that acquired chromosomal abnormalities in bone marrow (BM) cells are associated with clinical manifestations of myelodysplastic syndrome (MDS). However, to our knowledge, there are no reports that describe the association between chromosomal abnormalities in MDS and graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (allo-SCT). Here, we describe two MDS cases with trisomy 8 and der(1;7)(q10;p10), who developed severe GVHD after allo-SCT. We analyzed cytokine production and cell survival of monocytes from these patients with MDS before allo-SCT, in comparison with healthy controls or an MDS patient with a different chromosomal abnormality, who has not developed GVHD. The monocytes from MDS patients with trisomy 8 and der(1;7)(q10;p10) produced a larger amount of pro-inflammatory cytokine, tumor necrosis factor-?, and a smaller amount of anti-inflammatory cytokine, interleukin-10, on stimulation with Toll-like receptor (TLR) ligands. In addition, the monocytes from MDS cases with GVHD showed a decrease in apoptotic cell death upon stimulation with TLR ligands. We also detected host-derived pro-inflammatory antigen-presenting cells (APCs) in skin GVHD lesions after allo-SCT. These data suggest that trisomy 8 and der(1;7)(q10;p10) may be associated with the development of severe GVHD, by prolonging survival of pro-inflammatory host-derived APCs in GVHD lesions. PMID:23470132

Arai, Yasuyuki; Yamashita, Kouhei; Mizugishi, Kiyomi; Takaori-Kondo, Akifumi; Chiba, Tsutomu; Watanabe, Tomohiro

2013-06-01

368

Detection of numerical chromosomal abnormalities (chr. 1 and 18) before and after photodynamic therapy of human bladder carcinoma cells in vitro  

NASA Astrophysics Data System (ADS)

The application of nonradioactive in situ hybridization with chromosome-specific probes for cytogenetic analysis has increased significantly in recent years. In the field of photodynamic therapy (PDT) the hypothesis is that after PDT the remaining viable malignant cells are potentially metastatic cells. Therefore, we performed in vitro experiments on human bladder carcinoma cells to evaluate numerical chromosomal abnormalities before and after PDT. The possible genotoxic effect of PDT with porphycene (AamTPPn) appears to be small based on criteria such as numerical chromosomal abnormalities for chromosome 1 and 18.

Bachor, Ruediger; Reich, Ella D.; Kleinschmidt, Klaus; Hautmann, Richard E.

1997-12-01

369

Male gametophyte development and two different DNA classes of pollen grains in Rumex acetosa L., a plant with an XX\\/XY 1 Y 2 sex chromosome system and a female-biased sex ratio  

Microsoft Academic Search

Female-biased sex ratio is an interesting phenomenon observed in Rumex acetosa, a dioecious plant with an XX\\/XY1Y2 sex chromosome system. Previous authors have suggested that the biased sex ratio in this species is conditioned not only\\u000a postzygotically (sex-differential sporophytic mortality) but also prezygotically, because the sex ratio of seeds is also female-biased,\\u000a although to a lesser extent than the sex

Magdalena B?ocka-Wandas; Elwira Sliwinska; Aleksandra Grabowska-Joachimiak; Krystyna Musial; Andrzej J. Joachimiak

2007-01-01

370

Meiotic Sex Chromosome Inactivation Is Disrupted in Sterile Hybrid Male House Mice  

PubMed Central

In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid male sterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis.

Campbell, Polly; Good, Jeffrey M.; Nachman, Michael W.

2013-01-01

371

The effect of W chromosome origin on sex-chromosome pairing in ZZWW tetraploid females of the domesticated silkworm, Bombyx mori, and the congenic wild silkworm, Bombyx mandarina.  

PubMed

To analyze the degree of pairing of the Z and W chromosomes in ZZWW tetraploid female silkworms that have the W chromosomes of the domesticated silkworm, Bombyx mori, and those of the wild silkworm, Bobyx mandarina, we induced two types of ZZWW tetraploid female silkworms (Cr4n, Wr4n) through cold treatment of the eggs. The Wr4n female is congenic to the Cr4n female for W chromosomes; namely, the W chromosomes of the Wr4n female are derived from those of B. mandarina. Each of the sex ratios (female/male) in filial triploids from the Cr4n females was shown to be in the range of 3.9-5.3 (4.6 as an average of six cases). On the other hand, each of the sex ratios (female/male) in filial triploids from the Wr4n females was shown to be in the range of 6.2-9.0 (6.9 as an average of nine cases). The results of a t-test indicated that the difference in sex ratios in the two groups is highly significant (at the 0.1% level). These results suggest that, in the meiosis of the ZZWW tetraploid female, the frequency of pairing of the W chromosome of B. mandarina and the Z chromosome of B. mori is lower than that of the pairing of the W and Z chromosomes of B. mori. Furthermore, the t-test results are evidence that the W chromosomes have undergone significant evolutional change. PMID:11990764

Tanaka, N; Yokoyama, T; Abe, H; Ninagi, O; Oshiki, T

2002-01-01

372

Diverse stages of sex-chromosome differentiation in tinamid birds: evidence from crossover analysis in Eudromia elegans and Crypturellus tataupa.  

PubMed

All extant birds share the same sex-chromosome system: ZZ males and ZW females with striking differences in the stages of sex-chromosome differentiation between the primitive palaeognathus ratites and the large majority of avian species grouped within neognaths. Evolutionarily close to ratites is the neotropical order Tinamiformes that has been scarcely explored regarding their ZW pair morphology and constitution. Tinamous, when compared to ratites, constitute a large group among Palaeognathae, therefore, exploring the extent of homology between the Z and W chromosomes in this group might reveal key features on the evolution of the avian sex chromosomes. We mapped MLH1 foci that are crossover markers on pachytene bivalents to determine the size and localization of the homologous region shared by the Z and W chromosomes in two tinamous: Eudromia elegans and Crypturellus tataupa. We found that the homologous (pseudoautosomal) region differ significantly in size between these two species. They both have a single recombination event on the long arm of the acrocentric Z and W chromosomes. However, in E. elegans the pseudoautosomal region occupies one-fourth of the W chromosome, while in C. tataupa it is restricted to the tip of the long arm of the W. The W chromosomes in these two species differ in their heterochromatin content: in E. elegans it shows a terminal euchromatic segment and in C. tataupa is completely heterochromatic. These results show that tinamous have ZW pairs with more diversified stages of differentiation compared to ratites. Finally, the idea that the avian proto-sex chromosomes started to diverge from the end of the long arm towards the centromere of an acrocentric pair is discussed. PMID:21567220

Pigozzi, María Inés

2011-06-01

373

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

SciTech Connect

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.

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

1994-09-01

374

Identification of the Sex-Determining Region of the Ceratitis Capitata Y Chromosome by Deletion Mapping  

PubMed Central

In the medfly Ceratitis capitata, the Y chromosome is responsible for determining the male sex. We have mapped the region containing the relevant factor through the analysis of Y-autosome translocations using fluorescence in situ hybridization with two different probes. One probe, the clone pY114, contains repetitive, Y-specific DNA sequences from C. capitata, while the second clone, pDh2-H8, consists of ribosomal DNA sequences from Drosophila hydei. Clone pY114 labeled most of the long arm and pDh2-H8 hybridizes to the short arm and the centromeric region of the long arm. In 12 of the analyzed 19 Y-autosome translocation strains, adjacent-1 segregation products survive to the late pupal or even adult stage and can, therefore, be sexed. This was correlated with the length of the Y fragment still present in these aberrant individuals and allowed us to map the male-determining factor to a region of the long arm representing ~15% of the entire Y chromosome. No additional factors, affecting for example fertility, were detected outside the male-determining region.

Willhoeft, U.; Franz, G.

1996-01-01

375

Intragenic sex-chromosomal crossovers of Xmrk oncogene alleles affect pigment pattern formation and the severity of melanoma in Xiphophorus.  

PubMed Central

The X and Y chromosomes of the platyfish (Xiphophorus maculatus) contain a region that encodes several important traits, including the determination of sex, pigment pattern formation, and predisposition to develop malignant melanoma. Several sex-chromosomal crossovers were identified in this region. As the melanoma-inducing oncogene Xmrk is the only molecularly identified constituent, its genomic organization on both sex chromosomes was analyzed in detail. Using X and Y allele-specific sequence differences a high proportion of the crossovers was found to be intragenic in the oncogene Xmrk, concentrating in the extracellular domain-encoding region. The genetic and molecular data allowed establishment of an order of loci over approximately 0.6 cM. It further revealed a sequence located within several kilobases of the extracellular domain-encoding region of Xmrk that regulates overexpression of the oncogene.

Gutbrod, H; Schartl, M

1999-01-01

376

Analysis of sex-mismatched human corneal transplants by fluorescence in situ hybridization of the sex-chromosomes.  

PubMed

The fate of the cells of corneal transplants has been controversial from the early days of keratoplasty. Various methods such as histological evaluation, radiolabeling of donor cells or Barr-body analysis have been applied to clarify the issue. However, the question whether the transplanted cells are replaced or survive, remains unsolved. In this study, we applied fluorescence in situ hybridization (FISH) of the X- and Y-chromosomes in paraffin sections of explanted sex-mismatched corneal transplants to distinguish between host and donor cells. Fourteen sex-mismatched cases with various reasons for explantation and different postoperative time intervals ranging from 11 months to 30 years were analysed. We found that all cell types, including epithelium, keratocytes and endothelial donor cells were replaced in most cases as early as 1 year after transplantation. In three cases, however, up to 26% of donor keratocytes were still detected up to 4.5 years after transplantation, demonstrating a certain individual variability in the process of replacement. Further studies must show if the extent and timing of donor cell replacement in clinically successful, totally clear transplants is different. Our results are in keeping with the phenomenon of recurrences of corneal dystrophies in the graft, the significant postoperative decline of the endothelial cell density, the fact that typical graft rejections usually take place within 1-2 years postoperatively and that relatively late rejections can occur in rare cases probably due to some surviving stromal keratocytes. Donor cell replacement is a special feature of corneal transplants when compared with other kinds of organ transplants and might be due to the presence of the same tissue type in the immediate neighbourhood of the graft. PMID:10079142

Wollensak, G; Green, W R

1999-03-01

377

Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality †  

PubMed Central

Biologists use genetic relatedness between family members to explain the evolution of many behavioural and developmental traits in humans, including altruism, kin investment and longevity. Women's post-menopausal longevity in particular is linked to genetic relatedness between family members. According to the ‘grandmother hypothesis’, post-menopausal women can increase their genetic contribution to future generations by increasing the survivorship of their grandchildren. While some demographic studies have found evidence for this, others have found little support for it. Here, we re-model the predictions of the grandmother hypothesis by examining the genetic relatedness between grandmothers and grandchildren. We use this new model to re-evaluate the grandmother effect in seven previously studied human populations. Boys and girls differ in the per cent of genes they share with maternal versus paternal grandmothers because of differences in X-chromosome inheritance. Here, we demonstrate a relationship between X-chromosome inheritance and grandchild mortality in the presence of a grandmother. With this sex-specific and X-chromosome approach to interpreting mortality rates, we provide a new perspective on the prevailing theory for the evolution of human female longevity. This approach yields more consistent support for the grandmother hypothesis, and has implications for the study of human evolution.

Fox, Molly; Sear, Rebecca; Beise, Jan; Ragsdale, Gillian; Voland, Eckart; Knapp, Leslie A.

2010-01-01