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1

Abnormal human sex chromosome constitutions  

SciTech Connect

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

NONE

1993-12-31

2

Chromosomal abnormalities  

SciTech Connect

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

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

1980-09-01

3

Chromosomal abnormalities  

Microsoft Academic Search

Cytogenetic studies from the peripheral blood of a patient with malignant lymphoma and rhematoid arthritis who was treated with intra-articular gold Au 198 revealed mosaicism with a normal female metaphase and a 43-chromosome metaphase. The abnormal cell line showed six missing normal chromosomes and three morphologically abnormal chromosomes. The trypsin-digested G-banding metaphases showed that the marker chromosomes were an isochromosome

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

1980-01-01

4

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

PubMed

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

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

2015-01-01

5

Ethical considerations regarding parental decisions for termination following prenatal diagnosis of sex chromosome abnormalities.  

PubMed

Termination rates following prenatal diagnosis of sex chromosome abnormalities have been reported to be in a very wide spectrum (12.7-86.5%) in various studies. The different attitudes in management of prenatal diagnosed sex chromosome abnormalities may depend on several factors as the type of the abnormality, the indication for prenatal testing, the number of previous healthy children and whether the pregnancy was assisted or spontaneous. In the current study, we look at prenatal diagnostic procedures carried out in our department over a period of 5 years (2002-2007). We did not detect sex chromosome abnormalities in the 43 cordocenteses and the 26 chorionic villus samples. Among the 1130 amniocentesis patients, 12 cases (1.06%) were diagnosed as having sex chromosome abnormalities. Five (41.67%) of 12 pregnancies with sex chromosome abnormalities were terminated (one case with 47,XXY, one case with 46,X,del(X), and three cases with 45,X karyotype); whereas seven pregnancies (58.33%) continued. Among the factors influencing parents' decision-making, the attitude of the health-care professional giving the post-diagnosis counseling seems to be the most important, next to the socio-economic and educational status of the parents. PMID:18990991

Yilmaz, Z; Sahin, F I; Bulakbasi, T; Yüregir, O O; Tarim, E; Yanik, F

2008-01-01

6

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.

Darryl Leja (National Human Genome Research Institute REV)

2005-04-14

7

Chromosome Abnormalities  

MedlinePLUS

... the occurence of genetic errors. Top of page Glossary of Terms When reading about chromosomes and chromosome ... of many of these words in the Talking Glossary of Genetic Terms . A few additional terms are ...

8

Sex Chromosome Abnormalities in Two State Hospitals for Patients requiring Special Security  

Microsoft Academic Search

THE association between sex chromatin abnormality and mental sub-normality is well established. The incidence of sex chromatin abnormality in the new-born male and female population is about 0.2 per cent and 0.08 per cent respectively; in institutionalized mentally sub-normal male and female populations about 1 per cent and 0.4 per cent respectively. Court Brown1 reported that a high proportion of

M. D. Casey

1966-01-01

9

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

PubMed Central

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

2011-01-01

10

Epilepsy and chromosomal abnormalities  

PubMed Central

Background Many chromosomal abnormalities are associated with Central Nervous System (CNS) malformations and other neurological alterations, among which seizures and epilepsy. Some of these show a peculiar epileptic and EEG pattern. We describe some epileptic syndromes frequently reported in chromosomal disorders. Methods Detailed clinical assessment, electrophysiological studies, survey of the literature. Results In some of these congenital syndromes the clinical presentation and EEG anomalies seems to be quite typical, in others the manifestations appear aspecific and no strictly linked with the chromosomal imbalance. The onset of seizures is often during the neonatal period of the infancy. Conclusions A better characterization of the electro clinical patterns associated with specific chromosomal aberrations could give us a valuable key in the identification of epilepsy susceptibility of some chromosomal loci, using the new advances in molecular cytogenetics techniques - such as fluorescent in situ hybridization (FISH), subtelomeric analysis and CGH (comparative genomic hybridization) microarray. However further studies are needed to understand the mechanism of epilepsy associated with chromosomal abnormalities. PMID:20438626

2010-01-01

11

Abnormalities of Sex Differentiation  

Microsoft Academic Search

Sex differentiation is determined by a cascade of events proceeding from chromosomal sex to the completion of sexual maturation at puberty. Many factors involved in this cascade have been identified. Here we focus on DAX-1, androgen receptor and cytochrome P450cl7, and discuss their functions in sex differentiation. We analyzed the DAX-1 genes of two unrelated Japanese patients with congenital adrenal

Hajime Nawata; Ryoichi Takayanagi; Toshihiko Yanase; Shoichiro Ikuyama; Taijirou Okabe

1996-01-01

12

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

13

Genomics of Sex and Sex Chromosomes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sex chromosomes are distinctive, not only because of their gender determining role, but also for genomic features that reflect their evolutionary history. The genomic sequences in the ancient sex chromosomes of humans and in the incipient sex chromosomes of medaka, stickleback, and papaya exhibit u...

14

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

PubMed Central

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

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

2015-01-01

15

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

PubMed

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

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

2015-01-01

16

A Case of ADHD and a Major Y Chromosome Abnormality  

ERIC Educational Resources Information Center

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

Mulligan, Aisling; Gill, Michael; Fitzgerald, Michael

2008-01-01

17

Sex Chromosomes in Land Plants  

E-print Network

Sex Chromosomes in Land Plants Ray Ming,1 Abdelhafid Bendahmane,2,3 and Susanne S. Renner4 1 chromosomes, suppression of recombination Abstract Sex chromosomes in land plants can evolve as a consequence chromosomes in hepatics, mosses, and gymnosperms are morphologically heteromor- phic. In angiosperms

Renner, Susanne

18

Chromosomal abnormalities associated with omphalocele.  

PubMed

Fetuses with omphalocele have an increased risk for chromosomal abnormalities. The risk varies with maternal age, gestational age at diagnosis, association with umbilical cord cysts, complexity of associated anomalies, and the contents of omphalocele. There is considerable evidence that genetics contributes to the etiology of omphalocele. This article provides an overview of chromosomal abnormalities associated with omphalocele and a comprehensive review of associated full aneuploidy such as trisomy 18, trisomy 13, triploidy, trisomy 21, 45,X, 47,XXY, and 47,XXX, partial aneuploidy such as dup (3q), dup (11p), inv (11), dup (1q), del (1q), dup (4q), dup (5p), dup (6q), del (9p), dup (15q), dup(17q), Pallister-Killian syndrome with mosaic tetrasomy 12p and Miller-Dieker lissencephaly syndrome with deletion of 17p13.3, and uniparental disomy (UPD) such as UPD 11 and UPD 14. Omphalocele is a prominent marker for chromosomal abnormalities. Perinatal identification of omphalocele should alert chromosomal abnormalities and familial unbalanced translocations, and prompt thorough cytogenetic investigations and genetic counseling. PMID:17389182

Chen, Chih-Ping

2007-03-01

19

Plant sex chromosomes.  

PubMed

Dioecious species are known in plants and, as in many animals, some have distinguishable sex chromosomes. Genetic maps have identified sex-determining regions in several plants, and mapped male-specific Y (MSY) regions of the chromosome in which crossing over and genetic recombination do not occur, allowing sequence divergence between the X and Y. Divergence values of the few X-Y gene pairs so far available show that recombination between different genes of Silene latifolia stopped at different times. Once recombination stops, MSY genome regions are predicted to accumulate repetitive sequences, including transposable elements, resulting in low gene density. This has been documented in papaya but not yet in other plants. Y-linked genes should also accumulate deleterious mutations, eventually being lost as dosage compensation evolves. The few available data suggest that many plant MSY genes are functional, perhaps because genes required for male gametophyte functions degenerate slowly. Detailed studies of sex-linked genes are needed to test for deleterious substitutions in Y genes, and to date the origins of plant sex chromosomes. PMID:18756079

Charlesworth, D

2008-01-01

20

Dosage Compensation of the Sex Chromosomes  

PubMed Central

Differentiated sex chromosomes evolved because of suppressed recombination once sex became genetically controlled. In XX/XY and ZZ/ZW systems, the heterogametic sex became partially aneuploid after degeneration of the Y or W. Often, aneuploidy causes abnormal levels of gene expression throughout the entire genome. Dosage compensation mechanisms evolved to restore balanced expression of the genome. These mechanisms include upregulation of the heterogametic chromosome as well as repression in the homogametic sex. Remarkably, strategies for dosage compensation differ between species. In organisms where more is known about molecular mechanisms of dosage compensation, specific protein complexes containing noncoding RNAs are targeted to the X chromosome. In addition, the dosage-regulated chromosome often occupies a specific nuclear compartment. Some genes escape dosage compensation, potentially resulting in sex-specific differences in gene expression. This review focuses on dosage compensation in mammals, with comparisons to fruit flies, nematodes, and birds. PMID:22974302

Disteche, Christine M.

2013-01-01

21

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. PMID:23776360

Theisen, Aaron; Shaffer, Lisa G

2010-01-01

22

SEX CHROMOSOMES IN FLOWERING PLANTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

23

Numerically abnormal chromosome constitutions in humans  

SciTech Connect

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

NONE

1993-12-31

24

Reconstructing the Evolution of Vertebrate Sex Chromosomes  

E-print Network

Sex chromosomes and their evolution have captivated researchers since their discovery. For more than 100 years, the dominant model of sex chromosome evolution has held that differentiated sex chromosomes, such as the X and ...

Bellott, Daniel W.

25

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

SciTech Connect

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

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

1994-09-01

26

Numerous Transitions of Sex Chromosomes in Diptera  

PubMed Central

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

Vicoso, Beatriz; Bachtrog, Doris

2015-01-01

27

Specific Chromosomal Abnormalities in Malignant Human Gliomas1  

Microsoft Academic Search

Karyotypic analysis of 54 malignant human gliomas (5 anaplastic asina-)tomas, 43 glioblastoma multiformes, 3 gliosarcomas, 2 giant cell glioblastomas, 1 anaplastic mixed glioma) has demonstrated that 12 tumors contained normal stemlines or only lacked one sex chromosome. The 42 tumors with abnormal karyotypes included 38 tumors which could be completely analyzed. Six of these 38 cases had near-triploid or near-

Sandra H. Bigner; Joachim Mark; Peter C. Burger; M. Stephen; Dennis E. Bullan; Lawrence H. Muhlbaier; Dareil D. Bigner

1988-01-01

28

Sex chromosomes and their abnormalities  

E-print Network

of some X-linked diseases #12;X-linked mental retardation Estimated incidence of 1 in 500-1000 Mutations with mental retardation 20-40% excess males among persons with mental retardation Cytogenetic analysis Infertile May be slow learners, but rarely mentally retarded 1 Barr body 1/500 male births #12;Triplo

Dellaire, Graham

29

Four families with immunodeficiency and chromosome abnormalities.  

PubMed Central

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

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

1979-01-01

30

Chromosomal Abnormality in Men with Impaired Spermatogenesis  

PubMed Central

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

Mierla, Dana; Jardan, Dumitru; Stoian, Veronica

2014-01-01

31

Chromosomal abnormalities in a psychiatric population  

SciTech Connect

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

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

1995-02-27

32

Paternity uncertainty overrides sex chromosome selection for preferential grandparenting  

E-print Network

Paternity uncertainty overrides sex chromosome selection for preferential grandparenting Elizabeth 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

Getz, Wayne M.

33

Recent Origin of the Papaya Sex Chromosomes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sex chromosomes in flowering plants, in contrast to those in animals, evolved relatively recently and only a few are heteromorphic. The sex chromosomes of papaya appear at the cytological level to be homomorphic but, at the molecular level, we are finding that the papaya Y chromosome shows features ...

34

autosomal segments to the sex chromosomes.  

E-print Network

sex chromosomes of platypus and echidna are not completely identical and several share homology in platypus and echidna: autosomal location of SOX3 confirms the absence of SRY from monotremes. Chromosome

Schafer, William R.

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

Chromosome abnormalities in primary ovarian cancer  

SciTech Connect

Chromosome abnormalities that are specific and recurrent may occur in regions of the genome that are involved in the conversion of normal cells to those with tumorigenic potential. Ovarian cancer is the primary cause of death among patients with gynecological malignancies. We have performed cytogenetic analysis of 16 ovarian tumors from women age 28-82. Three tumors of low malignant potential and three granulosa cell tumors had normal karyotypes. To look for the presence of trisomy 12, which has been suggested to be a common aberration in this group of tumors, interphase fluorescence in situ hybridization was performed on direct preparations from three of these tumors using a probe for alpha satellite sequences of chromosome 12. In the 3 preparations, 92-98 percent of the cells contained two copies of chromosome 12, indicating that trisomy 12 is not a universal finding in low grade ovarian tumors. Endometrioid carcinoma of the ovary is histologically indistinguishable from endometial carcinoma of the uterus. We studied 10 endometrioid tumors to determine the degree of genetic similarity between these two carcinomas. Six out of ten endometrioid tumors showed a near-triploid modal number, and one presented with a tetraploid modal number. Eight of the ten contained structural chromosome abnormalities, of which the most frequent were 1p- (5 tumors), 19q+ (3 tumors), 6q- or ins(6) (4 tumors), 3q- or 3q+ (4 tumors). These cytogenetic results resemble those reported for papillary ovarian tumors and differ from those of endometrial carcinoma of the uterus. We conclude that despite the histologic similarities between the endometrioid and endometrial carcinomas, the genetic abnormalities in the genesis of these tumors differ significantly.

Yonescu, R.; Currie, J.; Griffin, C.A. [John Hopkins Univ., Baltimore, MD (United States)

1994-09-01

37

Extreme heterochiasmy and nascent sex chromosomes in European tree frogs  

E-print Network

Extreme heterochiasmy and nascent sex chromosomes in European tree frogs Laura Berset arborea, a species with nascent sex chromosomes and male heterogamety. Twenty microsatellites were in females). This opposes classical models of sex chromosome evolution, which envision an initially small

Alvarez, Nadir

38

Undetected sex chromosome aneuploidy by chromosomal microarray.  

PubMed

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

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

2012-11-01

39

The role of the sex chromosomes in mammalian germ cell differentiation  

E-print Network

The role of the sex chromosomes in mammalian germ cell differentiation P. S. BURGOYNE Department. An analysis is presented of the relationship between abnormalities of mamma- lian germ cell differentiation and their sex-chromosomal make-up. It is concluded that germ cells in an ovary require two functional X

Paris-Sud XI, Université de

40

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

Microsoft Academic Search

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

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

1994-01-01

41

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

42

Sequence of the chicken sex chromosomes  

E-print Network

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

Bellott, Daniel Winston

2010-01-01

43

Meiosis and chromosome painting of sex chromosome systems in Ceboidea.  

PubMed

The identity of the chromosomes involved in the multiple sex system of Alouatta caraya (Aca) and the possible distribution of this system among other Ceboidea were investigated by chromosome painting of mitotic cells from five species and by analysis of meiosis at pachytene in two species. The identity of the autosome #7 (X2) involved in the multiple system of Aca and its breakage points were demonstrated by both meiosis and chromosome painting. These features are identical to those described by Consigliere et al. [1996] in Alouatta seniculus sara (Assa) and Alouatta seniculus arctoidea (Asar). This multiple system was absent in the other four Ceboidea species studied here. However, data from the literature strongly suggest the presence of this multiple in other members of this genus. The presence of this multiple system among several species and subspecies that show high levels of chromosome rearrangements may suggest a special selective value of this multiple. The meiotic features of the sex systems of Aca and Cebus apella paraguayanus (Cap) are strikingly different at pachytene, as the latter system is similar to the sex pair of man and other primates. The relatively large genetic distances between species presently showing this multiple system suggest that its origin is not recent. Other members of the same genus should be investigated at meiosis and by chromosome painting in order to know the extent and distribution of this complex sex-chromosome system. PMID:11376445

Mudry, M D; Rahn, I M; Solari, A J

2001-06-01

44

Sex Chromosome Complement Influences Functional Callosal Myelination  

PubMed Central

In addition to androgen differences between males and females, there are genetic differences that are caused by unequal dosage of sex chromosome genes. Using the cuprizone-induced demyelination model, we recently showed that surgical gonadectomy of adult mice resulted in decreased normal myelination and remyelination compared to gonadally intact animals, suggesting a supporting role for sex hormones in the maintenance of myelination. However, inherent sex differences in normal myelination and remyelination persisted even after gonadectomy, with males consistently remyelinating to a lesser extent relative to normal myelination as assayed by axon conduction and immunohistochemistry. This suggests a potential role for the sex chromosome complement in mediating the differential rates of remyelination observed in males and females. The present study focuses on the impact that sex chromosomes might have on these myelination differences. Making use of the four core-genotype \\mice and cuprizone-diet induced demyelination/remyelination paradigm, our results demonstrate sex chromosome mediated asymmetry between XX and XY mice. The rate of functional remyelination following cuprizone diet-induced callosal demyelination in four core-genotype mice is attenuated in XY compared to XX animals of both gonadal sexes. Importantly, this difference arises only in the absence of circulating sex hormones following gonadectomy and confirms the role of sex hormones in the remyelination process reported earlier by our group. Because a genotype-mediated difference only arises following gonadectomy, the chromosomal contribution to myelination and remyelination is subtle yet significant. To explain this difference, we propose a possible asymmetry in expression of myelination-related genes in XX versus XY mice that needs to be investigated in future studies. PMID:23597832

Moore, Spencer; Patel, Rhusheet; Hannsun, Gemmy; Yang, Joy; Tiwari-Woodruff, Seema K.

2013-01-01

45

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. PMID:22191050

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

2011-01-01

46

Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)  

E-print Network

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

Shapiro, Mike

47

Female Meiotic Sex Chromosome Inactivation in Chicken  

PubMed Central

During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI) leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW), whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs) may contribute to silencing of Z. Surprisingly, ?H2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of ?H2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses ?H2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis. PMID:19461881

Schoenmakers, Sam; Wassenaar, Evelyne; Hoogerbrugge, Jos W.; Laven, Joop S. E.; Grootegoed, J. Anton; Baarends, Willy M.

2009-01-01

48

Neo-sex chromosome inheritance across species in Silene hybrids.  

PubMed

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

Weingartner, L A; Delph, L F

2014-07-01

49

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. PMID:25031659

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

2014-01-01

50

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

E-print Network

Chromosomal Gene Movements Reflect the Recent Origin and Biology of Therian Sex Chromosomes Lukasz, IFR 140, Universite´ Rennes I, Campus de Beaulieu, Rennes, France Mammalian sex chromosomes stem from during, but also after, male meiotic sex chromosome inactivation (MSCI). Thus, sexually antagonistic

Paris-Sud XI, Université de

51

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

PubMed

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

Hall, Heather; Hunt, Patricia; Hassold, Terry

2006-06-01

52

Avian sex chromosomes: dosage compensation matters.   

E-print Network

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

McQueen, Heather A; Clinton, Michael

2009-01-01

53

THE EVOLUTION OF SEX CHROMOSOMES IN PAPAYA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Papaya (Carica papaya L.) is one of plant species with male, female, and hermaphrodite plants. Sex determination in papaya is controlled by a primitive Y chromosome that contains a male-specific region with severe recombination suppression and DNA sequence degeneration. Our recent results showed tha...

54

Psychoeducational Implications of Sex Chromosome Anomalies  

ERIC Educational Resources Information Center

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

Wodrich, David L.; Tarbox, Jennifer

2008-01-01

55

Plant sex chromosomes: molecular structure and function.  

PubMed

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

Jamilena, M; Mariotti, B; Manzano, S

2008-01-01

56

Signatures of sex-antagonistic selection on recombining sex chromosomes.  

PubMed

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

Kirkpatrick, Mark; Guerrero, Rafael F

2014-06-01

57

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

58

The role of chromosome abnormalities in reproductive failure  

E-print Network

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

Boyer, Edmond

59

A primitive Y chromosome in papaya marks incipient sex chromosome evolution  

Microsoft Academic Search

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

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

2004-01-01

60

On the origin of sex chromosomes from meiotic drive.  

PubMed

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

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

2015-01-01

61

A cytogenetic view of sex chromosome evolution in plants.  

PubMed

The recent origin of sex chromosomes in plant species provides an opportunity to study the early stages of sex chromosome evolution. This review focuses on the cytogenetic aspects of the analysis of sex chromosome evolution in plants and in particular, on the best-studied case, the sex chromosomes in Silene latifolia. We discuss the emerging picture of sex chromosome evolution in plants and the further work that is required to gain better understanding of the similarities and differences between the trends in animal and plant sex chromosome evolution. Similar to mammals, suppression of recombination between the X and Y in S. latifolia species has occurred in several steps, however there is little evidence that inversions on the S. latifolia Y chromosome have played a role in cessation of X/Y recombination. Secondly, in S. latifolia there is a lack of evidence for genetic degeneration of the Y chromosome, unlike the events documented in mammalian sex chromosomes. The insufficient number of genes isolated from this and other plant sex chromosomes does not allow us to generalize whether the trends revealed on S. latifolia Y chromosome are general for other dioecious plants. Isolation of more plant sex-linked genes and their cytogenetic mapping with fluorescent in situ hybridisation (FISH) will ultimately lead to a much better understanding of the processes driving sex chromosome evolution in plants. PMID:18504353

Armstrong, S J; Filatov, D A

2008-01-01

62

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

E-print Network

Abstract 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...

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

2013-07-03

63

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

E-print Network

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

Nachman, Michael

64

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

Microsoft Academic Search

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

Roman Hobza; Eduard Kejnovsky; Boris Vyskot; Alex Widmer

2007-01-01

65

The key role of repeated DNAs in sex chromosome evolution in two fish species with ZW sex chromosome system  

PubMed Central

Despite substantial progress, there are still several gaps in our knowledge about the process of sex chromosome differentiation. The degeneration of sex-specific chromosome in some species is well documented, but it is not clear if all species follow the same evolutionary pathway. The accumulation of repetitive DNA sequences, however, is a common feature. To better understand this involvement, fish species emerge as excellent models because they exhibit a wide variety of sex chromosome and sex determining systems. Besides, they have much younger sex chromosomes compared to higher vertebrates, making it possible to follow early steps of differentiation. Here, we analyzed the arrangement of 9 repetitive DNA sequences in the W chromosomes of 2 fish species, namely Leporinus reinhardti and Triportheus auritus, which present well-differentiated ZZ/ZW sex system, but differ in respect to the size of the sex-specific chromosome. Both W chromosomes are almost fully heterochromatic, with accumulation of repeated DNAs in their heterochromatic regions. We found that microsatellites have strongly accumulated on the large W chromosome of L. reinhardti but not on the reduced-size W chromosome of T. auritus and are therefore important players of the W chromosome expansion. The present data highlight that the evolution of the sex chromosomes can diverge even in the same type of sex system, with and without the degeneration of the specific-sex chromosome, being more dynamic than traditionally appreciated. PMID:22658074

2012-01-01

66

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

PubMed

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

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

2009-02-01

67

Genetic analysis of sex chromosomal meiotic mutants in Drosophilia melanogaster.  

PubMed

A total of 209 ethyl methanesulfonate-treated X chromosomes were screened for meiotic mutants that either (1) increased sex or fourth chromosome nondisjunction at either meiotic division in males; (2) allowed recombination in such males; (3) increased nondisjunction of the X chromosome at either meiotic division in females; or (4) caused such females, when mated to males heterozygous for Segregation-Distorter (SD) and a sensitive homolog to alter the strength of meiotic drive in males.-Twenty male-specific meiotic mutants were found. Though the rates of nondisjunction differed, all twenty mutants were qualitatively similar in that (1) they alter the disjunction of the X chromosome from the Y chromosome; (2) among the recovered sex-chromosome exceptional progeny, there is a large excess of those derived from nullo-XY as compared to XY gametes; (3) there is a negative correlation between the frequency of sex-chromosome exceptional progeny and the frequency of males among the regular progeny. In their effects on meiosis these mutants are similar to In(1)sc(4L)sc(8R), which is deleted for the basal heterochromatin. These mutants, however, have normal phenotypes and viabilities when examined as X/0 males, and furthermore, a mapping of two of the mutants places them in the euchromatin of the X chromosome. It is suggested that these mutants are in genes whose products are involved in insuring the proper functioning of the basal pairing sites which are deleted in In(1)sc(4L)sc(8R), and in addition that there is a close connection, perhaps causal, between the disruption of normal X-Y pairing (and, therefore, disjunction) and the occurrence of meiotic drive in the male.-Eleven mutants were found which increased nondisjunction in females. These mutants were characterized as to (1) the division at which they acted; (2) their effect on recombination; (3) their dominance; (4) their effects on disjunction of all four chromosome pairs. Five female mutants caused a nonuniform decrease in recombination, being most pronounced in distal regions, and an increase in first division nondisjunction of all chromosome pairs. Their behavior is consistent with the hypothesis that these mutants are defective in a process which is a precondition for exchange. Two female mutants were allelic and caused a uniform reduction in recombination for all intervals (though to different extents for the two alleles) and an increase in first-division nondisjunction of all chromosomes. Limited recombination data suggest that these mutants do not alter coincidence, and thus, following the arguments of Sandler et al. (1968), are defective in exchange rather than a precondiiton for exchange. A single female mutant behaves in a manner that is consistent with it being a defect in a gene whose functioning is essential for distributive pairing. Three of the female meiotic mutants cause abnormal chromosome behavior at a number of times in meiosis. Thus, nondisjunction at both meiotic divisions is increased, recombinant chromosomes nondisjoin, and there is a polarized alteration in recombination.-The striking differences between the types of control of meiosis in the two sexes is discussed and attention is drawn to the possible similarities between (1) the disjunction functions of exchange and the process specified by the chromosome-specific male mutants; and (2) the prevention of functional aneuploid gamete formation by distributive disjunction and meiotic drive. PMID:4625747

Baker, B S; Carpenter, A T

1972-06-01

68

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

69

Silver-Stained accessory structures on human sex chromosomes  

Microsoft Academic Search

Using a combination of silver-staining and light microscopic techniques on human male meiotic preparations, it is feasible to study the morphology and behavior of both autosomal synaptonemal complexes and sex chromosome axes. During leptotene and early zygotene, the X and Y chromosomes are separate; their axes appearing as thin, filamentous structures. During late zygotene\\/early pachytene, the sex chromosomes come close

S. Pathak; F. F. B. Elder

1980-01-01

70

Sex Chromosome Complement Affects Nociception and Analgesia in Newborn Mice  

E-print Network

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

Sandini, Giulio

71

Autosomal origin of sex chromosome in a polyploid plant  

Technology Transfer Automated Retrieval System (TEKTRAN)

While theory on sex chromosome evolution is well developed, evidence of the early stages of this process remains elusive, in part because this process unfolded in many animals so long ago. The relatively recent and repeated evolution of separate sexes (dioecy) and sex chromosomes in plants, however,...

72

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

SciTech Connect

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

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

1994-10-15

73

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

74

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.

75

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. PMID:23822802

2013-01-01

76

Cervical adenocarcinoma identification by testing for chromosomal abnormalities.  

PubMed

We report on a case of cervical adenocarcinoma in situ in a 42-year-old woman with a history of human papillomavirus infection. Repeat cytology, human papillomavirus testing, and colposcopy failed to identify the lesion. Testing of the cervical cell DNA identified chromosomal abnormalities, prompting a cervical cone biopsy, which identified adenocarcinoma in situ. PMID:24283864

Dittus, Janet L; Dudley, Bunyan S; Upender, Madhvi; Endress, Gregory A

2013-12-01

77

Mechanisms and consequences of paternally transmitted chromosomal abnormalities  

SciTech Connect

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

Marchetti, F; Wyrobek, A J

2005-04-05

78

"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. PMID:20152051

2010-01-01

79

High degree of sex chromosome differentiation in stickleback fishes  

PubMed Central

Background Studies of closely related species with different sex chromosome systems can provide insights into the processes of sex chromosome differentiation and evolution. To investigate the potential utility of molecular markers in studying sex chromosome differentiation at early stages of their divergence, we examined the levels and patterns of genetic differentiation between sex chromosomes in nine-spined (Pungitius pungitius) and three-spined sticklebacks (Gasterosteus aculeatus) using microsatellite markers. Results A set of novel microsatellite markers spanning the entire length of the sex chromosomes were developed for nine-spined sticklebacks using the sequenced genomes of other fish species. Sex-specific patterns of genetic variability and male-specific alleles were identified at most of these loci, indicating a high degree of differentiation between the X and Y chromosomes in nine-spined sticklebacks. In three-spined sticklebacks, male-specific alleles were detected at some loci confined to two chromosomal regions. In addition, male-specific null alleles were identified at several other loci, implying the absence of Y chromosomal alleles at these loci. Overall, male-specific alleles and null alleles were found over a region spanning 81% of the sex chromosomes in three-spined sticklebacks. Conclusions High levels but distinct patterns of sex chromosome differentiation were uncovered in the stickleback species that diverged 13 million years ago. Our results suggest that the Y chromosome is highly degenerate in three-spined sticklebacks, but not in nine-spined sticklebacks. In general, the results demonstrate that microsatellites can be useful in identifying the degree and patterns of sex chromosome differentiation in species at initial stages of sex chromosome evolution. PMID:21958112

2011-01-01

80

Sex Chromosome-Specific Regulation in the Drosophila Male Germline But Little Evidence for Chromosomal  

E-print Network

Sex Chromosome-Specific Regulation in the Drosophila Male Germline But Little Evidence for Chromosomal Dosage Compensation or Meiotic Inactivation Colin D. Meiklejohn*, Emily L. Landeen, Jodi M. Cook, United States of America Abstract The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW

Dean, Matthew D.

81

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

PubMed Central

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

2014-01-01

82

Further chromosomal studies on Ellobius lutescens: heteromorphism of chromosome No. 1 is not associated with sex determination.  

PubMed

Twelve animals of the species Ellobius lutescens from two generations were studied with various chromosomal banding techniques. This species carries 17 chromosomes in both sexes. In preceding studies chromosomal sex determination was assigned to different structural variants of chromosome No. 1. In the present study, no definite chromosomal basis for sex determination was found. PMID:3536574

Djalali, M; Hameister, H; Vogel, W

1986-12-01

83

Chromosome abnormalities in embryos from lines of Japanese quail divergently selected for body weight  

E-print Network

Chromosome abnormalities in embryos from lines of Japanese quail divergently selected for body analysis was made of 927 embryos from lines of Japanese quail (coturnix) divergently selected for body). Key words :Japanese quail, coturnix, embryos, chromosome abnormality, heteroploidy. Résumé Anomalies

Paris-Sud XI, Université de

84

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. PMID:22189045

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

2011-01-01

85

Variables influencing pregnancy termination following prenatal diagnosis of fetal chromosome abnormalities.  

PubMed

The objective of this study was to identify variables that may influence the decision to terminate or continue a pregnancy affected by a chromosome abnormality. We performed a retrospective cohort analysis of 286 pregnancies diagnosed with a chromosome abnormality following genetic counseling and prenatal diagnosis. Data obtained included procedure type, chromosome results, ethnicity, maternal age, use of fertility treatments, and uptake of genetic counseling after results, among other factors. Wilcoxon rank sum test, Fisher's exact test, and univariate and multivariate logistic regression models were used for data analysis. The overall termination rate in this study was 82.9 %. A lower likelihood to terminate was found in pregnancies with a diagnosis of a sex chromosome abnormality (OR 0.05, p?

Hawkins, Anne; Stenzel, Ana; Taylor, Joanne; Chock, Valerie Y; Hudgins, Louanne

2013-04-01

86

Never settling down: frequent changes in sex chromosomes.  

PubMed

A new study reveals multiple dramatic changes in sex chromosome structure and identity in flies; such transitions are accompanied by a series of genomic events that affect chromosome biology, gene regulation, and sex determination. See the accompanying Research Article. PMID:25881199

Wei, Kevin H-C; Barbash, Daniel A

2015-04-01

87

Single Origin of Sex Chromosomes and Multiple Origins of B Chromosomes in Fish Genus Characidium  

PubMed Central

Chromosome painting with DNA probes obtained from supernumerary (B) and sex chromosomes in three species of fish genus Characidium (C. gomesi, C. pterostictum and C. oiticicai) showed a close resemblance in repetitive DNA content between B and sex chromosomes in C. gomesi and C. pterostictum. This suggests an intraspecific origin for B chromosomes in these two species, probably deriving from sex chromosomes. In C. oiticicai, however, a DNA probe obtained from its B chromosome hybridized with the B but not with the A chromosomes, suggesting that the B chromosome in this species could have arisen interspecifically, although this hypothesis needs further investigation. A molecular phylogenetic analysis performed on nine Characidium species, with two mtDNA genes, showed that the presence of heteromorphic sex chromosomes in these species is a derived condition, and that their origin could have been unique, a conclusion also supported by interspecific chromosome painting with a CgW probe derived from the W chromosome in C. gomesi. Summing up, our results indicate that whereas heteromorphic sex chromosomes in the genus Characidium appear to have had a common and unique origin, B chromosomes may have had independent origins in different species. Our results also show that molecular phylogenetic analysis is an excellent complement for cytogenetic studies by unveiling the direction of evolutionary chromosome changes. PMID:25226580

Pansonato-Alves, José Carlos; Serrano, Érica Alves; Utsunomia, Ricardo; Camacho, Juan Pedro M.; da Costa Silva, Guilherme José; Vicari, Marcelo Ricardo; Artoni, Roberto Ferreira; Oliveira, Cláudio; Foresti, Fausto

2014-01-01

88

Maintenance of ancestral sex chromosomes in Palearctic tree frogs: direct evidence from Hyla orientalis.  

PubMed

Contrasting with the situation found in birds and mammals, sex chromosomes are generally homomorphic in poikilothermic vertebrates. This homomorphy was recently shown to result from occasional X-Y recombinations (not from turnovers) in several European species of tree frogs (Hyla arborea, H. intermedia and H. molleri). Because of recombination, however, alleles at sex-linked loci were rarely diagnostic at the population level; support for sex linkage had to rely on multilocus associations, combined with occasional sex differences in allelic frequencies. Here, we use direct evidence, obtained from anatomical and histological analyses of offspring with known pedigrees, to show that the Eastern tree frog (H. orientalis) shares the same pair of sex chromosomes, with identical patterns of male heterogamety and complete absence of X-Y recombination in males. Conservation of an ancestral pair of sex chromosomes, regularly rejuvenated via occasional X-Y recombination, seems thus a widespread pattern among Hyla species. Sibship analyses also identified discrepancies between genotypic and phenotypic sex among offspring, associated with abnormal gonadal development, suggesting a role for sexually antagonistic genes on the sex chromosomes. PMID:23735903

Stöck, M; Savary, R; Zaborowska, A; Górecki, G; Brelsford, A; Rozenblut-Ko?cisty, B; Ogielska, M; Perrin, N

2013-01-01

89

Meiotic abnormalities  

SciTech Connect

Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

NONE

1993-12-31

90

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

91

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

92

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

PubMed Central

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

2014-01-01

93

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

94

The genetics of sex chromosomes: evolution and implications for hybrid incompatibility  

PubMed Central

Heteromorphic sex chromosomes, where one sex has two different types of sex chromosomes, face very different evolutionary consequences than do the autosomes. Two important features of sex chromosomes arise from being present in only copy in one of the sexes: dosage compensation and the meiotic silencing of sex chromosomes. Other differences arise because sex chromosomes spend unequal amounts of time in each sex. Thus, the impact of evolutionary processes (mutation, selection, genetic drift, and meiotic drive) differs substantially between each sex chromosome, and between the sex chromosomes and the autosomes. Sex chromosomes also play a disproportionate role in Haldane’s rule and other important patterns related to hybrid incompatibility, and thus speciation. We review the consequences of sex chromosomes on hybrid incompatibility. A theme running through this review is that epigenetic processes, notably those related to chromatin, may be more important to the evolution of sex chromosomes and the evolution of hybrid incompatibility than previously recognized. PMID:23025408

Johnson, Norman A.; Lachance, Joseph

2012-01-01

95

Article de synthse Chromosome Y et dtermination du sexe  

E-print Network

Article de synthèse Chromosome Y et détermination du sexe J Weissenbach F Rouyer Unité de 1989) Résumé ― La structure puis la fonction du chromosome Y humain ont été abordées depuis quel chromosome Y et l'analyse, à l'aide de ces sondes, de ce chromosome chez des patients présen- tant des

Paris-Sud XI, Université de

96

Complex evolutionary trajectories of sex chromosomes across bird taxa.  

PubMed

Sex-specific chromosomes, like the W of most female birds and the Y of male mammals, usually have lost most genes owing to a lack of recombination. We analyze newly available genomes of 17 bird species representing the avian phylogenetic range, and find that more than half of them do not have as fully degenerated W chromosomes as that of chicken. We show that avian sex chromosomes harbor tremendous diversity among species in their composition of pseudoautosomal regions and degree of Z/W differentiation. Punctuated events of shared or lineage-specific recombination suppression have produced a gradient of "evolutionary strata" along the Z chromosome, which initiates from the putative avian sex-determining gene DMRT1 and ends at the pseudoautosomal region. W-linked genes are subject to ongoing functional decay after recombination was suppressed, and the tempo of degeneration slows down in older strata. Overall, we unveil a complex history of avian sex chromosome evolution. PMID:25504727

Zhou, Qi; Zhang, Jilin; Bachtrog, Doris; An, Na; Huang, Quanfei; Jarvis, Erich D; Gilbert, M Thomas P; Zhang, Guojie

2014-12-12

97

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

98

Comments on some genetic abnormalities of sex determination and sex differentiation in Homo sapiens  

Microsoft Academic Search

Man is a gonochoristic species with male hetero- and female homogamety. The basic plan of gonadal and genital development in both sexes is female unless testes are induced by H-Y antigen which is usually specified by the Y chromosome. Genitalia can develop in either direction in both sexes. In males testosterone produced by testicular Leydig cells causes Wolffian duct differentiation,

John M. Opitz

1980-01-01

99

The unique sex chromosome system in platypus and echidna.  

PubMed

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

Ferguson-Smith, M A; Rens, W

2010-10-01

100

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

PubMed Central

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

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

2014-01-01

101

Evolution of the sex chromosomes in salmonid fishes.  

PubMed

Most of the information on sex chromosomes in salmonid fishes is for species in the 3 genera of the subfamily Salmoninae found in North America: Salvelinus, Salmo and Oncorhynchus. All of the species are male heterogametic with XY sex determination. Morphologically distinguishable sex chromosomes are found only in Salvelinus namaycush,S. fontinalis and Oncorhynchus mykiss. Sex chromosomes have been identified in the other species using a combination of chromosome mapping and fluorescence in situ hybridization with probes containing sex-linked markers. Although all species share conserved linkage groups, the major sex-determining locus (SD) is found at the telomere of a different linkage group in almost every species, suggesting that the SD often transposes to a new location at the time of speciation. In a couple of species, intraspecific variation has been found in the chromosomal location of the SD. Recently, sdY has been identified as the major sex-determining gene in rainbow trout, and it maps to the sex linkage group in all of these species. BACs containing sdY have been isolated and sequenced in O.mykiss, and the genetic markers adjacent to sdY are not sex-linked in the other Oncorhynchus species, suggesting that the transposed region is very small. Possible explanations for the frequent occurrence of transposition of the SD are discussed. PMID:24107355

Phillips, R B

2013-01-01

102

Sex Chromosome Evolution in Amniotes: Applications for Bacterial Artificial Chromosome Libraries  

PubMed Central

Variability among sex chromosome pairs in amniotes denotes a dynamic history. Since amniotes diverged from a common ancestor, their sex chromosome pairs and, more broadly, sex-determining mechanisms have changed reversibly and frequently. These changes have been studied and characterized through the use of many tools and experimental approaches but perhaps most effectively through applications for bacterial artificial chromosome (BAC) libraries. Individual BAC clones carry 100–200?kb of sequence from one individual of a target species that can be isolated by screening, mapped onto karyotypes, and sequenced. With these techniques, researchers have identified differences and similarities in sex chromosome content and organization across amniotes and have addressed hypotheses regarding the frequency and direction of past changes. Here, we review studies of sex chromosome evolution in amniotes and the ways in which the field of research has been affected by the advent of BAC libraries. PMID:20981143

Janes, Daniel E.; Valenzuela, Nicole; Ezaz, Tariq; Amemiya, Chris; Edwards, Scott V.

2011-01-01

103

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

E-print Network

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

Canberra, University of

104

Diagnosis of four chromosome abnormalities of unknown origin by chromosome microdissection and subsequent reverse and forward painting  

SciTech Connect

A molecular cytogenetic method consisting of chromosome microdissection and subsequent reverse/forward chromosome painting is a powerful tool to identify chromosome abnormalities of unknown origin. We present 4 cases of chromosome structural abnormalities whose origins were ascertained by this method. In one MCA/MR patient with an add(5q)chromosome, fluorescence in situ hybridization (FISH), using probes generated from a microdissected additional segment of the add(5q) chromosome and then from a distal region of normal chromosome 5, confirmed that the patient had a tandem duplication for a 5q35-qter segment. Similarly, we ascertained that an additional segment of an add(3p) chromosome in another MCA/MR patient had been derived from a 7q32-qter segment. In a woman with a history of successive spontaneous abortions and with a minute marker chromosome, painting using microdissected probes from the whole marker chromosome revealed that it was i(15)(p10) or psu dic(15;15)(q11;q11). Likewise, a marker observed in a fetus was a ring chromosome derived from the paracentromeric region of chromosome 19. We emphasize the value of the microdissection-based chromosome painting method in the identification of unknown chromosomes, especially for marker chromosomes. The method may contribute to a collection of data among patients with similar or identical chromosome abnormalities, which may lead to a better clinical syndrome delineation. 15 refs., 2 figs.

Coelho, K.E.F.A. de; Egashira, M.; Kato, R. [Nagasaki Univ. School of Medicine (Japan)] [and others

1996-06-14

105

ETOPOSIDE INDUCES CHROMOSOMAL ABNORMALITIES IN SPERMATOCYTES AND SPERMATOGONIAL STEM CELLS  

SciTech Connect

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

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

2005-07-15

106

Microdissection and whole chromosome painting. Improving sex chromosome analysis in Triportheus (Teleostei, Characiformes).  

PubMed

Triportheus fish species present 2n = 52 chromosomes. The karyotypes show similar macrostructure and a ZZ/ZW sex chromosome system, which probably represents synapomorphy for the genus. A probe of the Z chromosome was obtained from T. nematurus through microdissection, followed by unspecific amplification via DOP-PCR. This probe was used for WCP (whole chromosome painting) through fluorescent in situ hybridization (FISH) in several other Triportheus species, to analyze the differentiation of the ZZ/ZW system. The homology between this probe and chromosomes of species from other genera, putatively related to Triportheus, was also examined to search for evidence about evolution of their sex chromosomes. Complete homology was found among the Z chromosomes of all Triportheus species, while only small positive signals were found on the W chromosomes. Hybridization signals were absent in species from other genera. The present results reinforce both the conservative nature of Z chromosomes and the hypothesis that the ZZ/ZW sex chromosome system is a synapomorphic feature of Triportheus. On the other hand, besides reduction of size, W chromosomes have undergone accentuated composition changes in relation to Z chromosomes, since only a small region, usually located in the short arm, kept homology with the Z chromosomes. PMID:19096212

Diniz, D; Laudicina, A; Cioffi, M B; Bertollo, L A C

2008-01-01

107

The evolution of sex chromosomes in organisms with separate haploid sexes.  

PubMed

The evolution of dimorphic sex chromosomes is driven largely by the evolution of reduced recombination and the subsequent accumulation of deleterious mutations. Although these processes are increasingly well understood in diploid organisms, the evolution of dimorphic sex chromosomes in haploid organisms (U/V) has been virtually unstudied theoretically. We analyze a model to investigate the evolution of linkage between fitness loci and the sex-determining region in U/V species. In a second step, we test how prone nonrecombining regions are to degeneration due to accumulation of deleterious mutations. Our modeling predicts that the decay of recombination on the sex chromosomes and the addition of strata via fusions will be just as much a part of the evolution of haploid sex chromosomes as in diploid sex chromosome systems. Reduced recombination is broadly favored, as long as there is some fitness difference between haploid males and females. The degeneration of the sex-determining region due to the accumulation of deleterious mutations is expected to be slower in haploid organisms because of the absence of masking. Nevertheless, balancing selection often drives greater differentiation between the U/V sex chromosomes than in X/Y and Z/W systems. We summarize empirical evidence for haploid sex chromosome evolution and discuss our predictions in light of these findings. PMID:25582562

Immler, Simone; Otto, Sarah Perin

2015-03-01

108

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

E-print Network

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

Ishii, Hitoshi

109

In vitro leukocyte sex chromosome replication patterns of bovine chimeras  

E-print Network

IN VITRO LEUKOCYTE SEX CHROMOSOME REPLICATION PATTERNS OF BOVINE CHIMERAS A Thesis by GEORGE MICHAEL HURLING Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1972 Maj or Subject: Genetics IN VITRO LEUKOCYTE SEX CHROMOSOME REPLICATION PATTERNS OF BOVINE CHIMERAS A Thesis by GEORGE MICHAEL BONLING Approved as to style and content by: ( airman of Committee) Head of Department) (Member...

Bowling, George Michael

1972-01-01

110

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

111

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. PMID:25031658

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

2014-01-01

112

Genetic aspects of human male infertility: the frequency of chromosomal abnormalities and Y chromosome microdeletions in severe male factor infertility  

Microsoft Academic Search

Objective: The main purpose of this study is to detect the frequency and type of both chromosomal abnormalities and Y chromosome microdeletions in patients with severe male factor infertility and fertile control subjects. The association between the genetic abnormality and clinical parameters was also evaluated. Methods: This study was carried out in 208 infertile and 20 fertile men. Results of

Arzu Vicdan; Kubilay Vicdan; Serdar Günalp; Aykut Kence; Cem Akarsu; Ahmet Zeki I??k; Eran Sözen

2004-01-01

113

Sex-chromosome turnovers: the hot-potato model.  

PubMed

Sex-determining systems often undergo high rates of turnover but for reasons that remain largely obscure. Two recent evolutionary models assign key roles, respectively, to sex-antagonistic (SA) mutations occurring on autosomes and to deleterious mutations accumulating on sex chromosomes. These two models capture essential but distinct key features of sex-chromosome evolution; accordingly, they make different predictions and present distinct limitations. Here we show that a combination of features from the two models has the potential to generate endless cycles of sex-chromosome transitions: SA alleles accruing on a chromosome after it has been co-opted for sex induce an arrest of recombination; the ensuing accumulation of deleterious mutations will soon make a new transition ineluctable. The dynamics generated by these interactions share several important features with empirical data, namely, (i) that patterns of heterogamety tend to be conserved during transitions and (ii) that autosomes are not recruited randomly, with some chromosome pairs more likely than others to be co-opted for sex. PMID:24334743

Blaser, Olivier; Neuenschwander, Samuel; Perrin, Nicolas

2014-01-01

114

Robin sequence associated with karyotypic mosaicism involving chromosome 22 abnormalities  

SciTech Connect

Robin sequence is characterized by cleft palate, hypoplastic mandible, glossoptosis and respiratory difficulties. The Robin sequence may be observed as an isolated defect or as part of about 33 syndromes; however, to our knowledge, it has never been reported associated with chromosome 22 abnormalities. We examined a two-month-old black boy with a severe case of Robin sequence. Exam revealed a small child with hypoplastic mandible, glossoptosis, high palate and respiratory difficulty with continuous apnea episodes resulting in cyanotic lips and nails. In order to relieve the upper airway obstruction, his tongue was attached to the lower lip. Later a tracheostomy was performed. On follow-up exam, this patient was found to have developmental delay. Cytogenetic studies of both peripheral blood and fibroblast cells showed mosaicism involving chromosome 22 abnormalities which were designated as follows: 45,XY,-22/46,XY,-22,+r(22)/46,XY. Fluorescence in situ hybridization (FISH) studies confirmed the identity of the r(22) and showed the presence of the DiGeorge locus (D22575) but the absence of the D22539 locus which maps to 22q13.3. Reported cases of r(22) show no association with Robin sequence. However, r(22) has been associated with flat bridge of the nose, bulbous tip of the nose, epicanthus and high palate, all characteristics that we also observed in this case. These unusual cytogenetic findings may be causally related to the dysmorphology found in the patient we report.

Salinas, C.F.; Jastrzab, J.M.; Centu, E.S. [Medical Univ. of South Carolina, Charleston, SC (United States)

1994-09-01

115

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

E-print Network

sex chromosome differentiation (reviewed in CHARLESWORTH 2000; CHARLESWORTH et al. 2005; MARSHALL1 Linkage analysis reveals independent origin of Poeciliid sex chromosomes and a case of atypical sex inheritance in the guppy (Poecilia reticulata) Namita Tripathi, Margarete Hoffmann, Detlef Weigel

Weigel, Detlef

116

Deciphering neo-sex and B chromosome evolution by the draft genome of Drosophila albomicans  

E-print Network

the formation of the human sex chromosomes, which were alsoSex chromosome evolution: platypus gene mapping suggests that part of the humanhuman Y is ~170 million years old [4]). An alternative solution is to study sex

2012-01-01

117

Novel Submicroscopic chromosomal abnormalities detected in Autism Spectrum Disorder  

PubMed Central

Background One genetic mechanism known to be associated with autism spectrum disorders (ASD) is chromosomal abnormalities. The identification of copy number variants (CNV) i.e. microdeletions and microduplications that are undetectable at the level of traditional cytogenetic analysis allows the potential association of submicroscopic chromosomal imbalances and human disease. Methods We performed array comparative genomic hybridization (aCGH) utilizing a 19K whole genome tiling path bacterial artificial chromosome (BAC) microarray on 397 unrelated subjects with autism spectrum disorder (ASD). Common CNV were excluded using a control group comprised of 372 individuals from the NIMH Genetics Initiative Control samples. Confirmation studies were performed on all remaining CNV using FISH (Fluorescence In Situ Hybridization), microsatellite analysis and/or quantitative PCR analysis. Results A total of 51 CNV were confirmed in 46 ASD subjects. Three maternal interstitial duplications of 15q11-q13 known to be associated with ASD were identified. The other 48 CNV ranged in size from 189 kb to 5.5 Mb and contained from 0 to ~40 RefSeq genes. Seven CNV were de novo and 44 were inherited. Conclusions 51 autism-specific CNV were identified in 46/397 ASD patients using a 19K BAC microarray for an overall rate of 11.6%. These microdeletions and microduplications cause gene dosage imbalance in 272 genes many of which could be considered as candidate genes for autism. PMID:18374305

Christian, Susan L.; Brune, Camille W.; Sudi, Jyotsna; Kumar, Ravinesh A.; Liu, Shaung; KaraMohamed, Samer; Badner, Judith A.; Matsui, Seiichi; Conroy, Jeffrey; McQuaid, Devin; Gergel, James; Hatchwell, Eli; Gilliam, T. Conrad; Gershon, Elliot S.; Nowak, Norma J.; Dobyns, William B.; Cook, Edwin H.

2008-01-01

118

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

PubMed Central

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

2011-01-01

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. PMID:24250941

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

2013-01-01

120

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. PMID:24250944

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

2013-01-01

121

Homomorphic sex chromosomes and the intriguing Y chromosome of Ctenomys rodent species (Rodentia, Ctenomyidae).  

PubMed

Unlike the X chromosome, the mammalian Y chromosome undergoes evolutionary decay resulting in small size. This sex chromosomal heteromorphism, observed in most species of the fossorial rodent Ctenomys, contrasts with the medium-sized, homomorphic acrocentric sex chromosomes of closely related C. maulinus and C. sp. To characterize the sequence composition of these chromosomes, fluorescent banding, self-genomic in situ hybridization, and fluorescent in situ hybridization with an X painting probe were performed on mitotic and meiotic plates. High molecular homology between the sex chromosomes was detected on mitotic material as well as on meiotic plates immunodetected with anti-SYCP3 and anti-?H2AX. The Y chromosome is euchromatic, poor in repetitive sequences and differs from the X by the loss of a block of pericentromeric chromatin. Inferred from the G-banding pattern, an inversion and the concomitant prevention of recombination in a large asynaptic region seems to be crucial for meiotic X chromosome inactivation. These peculiar findings together with the homomorphism of Ctenomys sex chromosomes are discussed in the light of the regular purge that counteracts Muller's ratchet and the probable mechanisms accounting for their origin and molecular homology. PMID:25227566

Suárez-Villota, Elkin Y; Pansonato-Alves, José C; Foresti, Fausto; Gallardo, Milton H

2014-01-01

122

Sex-chromosome turnovers induced by deleterious mutation load.  

PubMed

In sharp contrast with mammals and birds, many cold-blooded vertebrates present homomorphic sex chromosomes. Empirical evidence supports a role for frequent turnovers, which replace nonrecombining sex chromosomes before they have time to decay. Three main mechanisms have been proposed for such turnovers, relying either on neutral processes, sex-ratio selection, or intrinsic benefits of the new sex-determining genes (due, e.g., to linkage with sexually antagonistic mutations). Here, we suggest an additional mechanism, arising from the load of deleterious mutations that accumulate on nonrecombining sex chromosomes. In the absence of dosage compensation, this load should progressively lower survival rate in the heterogametic sex. Turnovers should occur when this cost outweighs the benefits gained from any sexually antagonistic genes carried by the nonrecombining sex chromosome. We use individual-based simulations of a Muller's ratchet process to test this prediction, and investigate how the relevant parameters (effective population size, strength and dominance of deleterious mutations, size of nonrecombining segment, and strength of sexually antagonistic selection) are expected to affect the rate of turnovers. PMID:23461315

Blaser, Olivier; Grossen, Christine; Neuenschwander, Samuel; Perrin, Nicolas

2013-03-01

123

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

124

A role for a neo-sex chromosome in stickleback speciation  

E-print Network

antagonism, or conflict between the sexes, has been proposed as a driving force in both sexARTICLES A role for a neo-sex chromosome in stickleback speciation Jun Kitano1 {, Joseph A. Ross1-chromosome turnover and speciation. Although closely related species often have different sex-chromosome systems

Chan, Yingguang

125

In the platypus a meiotic chain of ten sex chromosomes shares genes with the bird Z and mammal X chromosomes  

Microsoft Academic Search

Two centuries after the duck-billed platypus was discovered, monotreme chromosome systems remain deeply puzzling. Karyotypes of males, or of both sexes, were claimed to contain several unpaired chromosomes (including the X chromosome) that form a multi-chromosomal chain at meiosis. Such meiotic chains exist in plants and insects but are rare in vertebrates. How the platypus chromosome system works to determine

Frank Grützner; Willem Rens; Enkhjargal Tsend-Ayush; Nisrine El-Mogharbel; Patricia C. M. O'Brien; Russell C. Jones; Malcolm A. Ferguson-Smith; Jennifer A. Marshall Graves

2004-01-01

126

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

127

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

E-print Network

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

de Vries, Geert J.

128

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

129

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

PubMed

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

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

2007-01-01

130

Homologous expressed genes in the human sex chromosome pairing region  

Microsoft Academic Search

The human sex chromosomes share a pair of homologous genes which independently encode a cell-surface antigen defined by the monoclonal antibody 12E7 (refs 1, 2; see refs 3, 4 for review). The X-located homologue, MIC2X, escapes X-inactivation5 and the equivalent Y-located locus, MIC2Y, was one of the first genes shown to reside on a mammalian Y chromosome2. By using a

V. Buckle; C. Mondello; S. Darling; I. W. Craig; P. N. Goodfellow

1985-01-01

131

Cloning an expressed gene shared by the human sex chromosomes  

Microsoft Academic Search

The existence of genes shared by mammalian sex chromosomes has been predicted on both evolutionary and functional grounds. However, the only experimental evidence for such genes in humans is the cell-surface antigen encoded by loci on the X and Y chromosomes (MIC2X and MIC2Y, respectively), which is recognized by the monoclonal antibody 12E7. Using the bacteriophage lambdagt11 expression system in

S. M. Darling; G. S. Banting; B. Pym; J. Wolfe; P. N. Goodfellow

1986-01-01

132

Heterochromatin characterization of sex chromosomes in Triturus marmoratus (Urodela, Salamandridae)  

Microsoft Academic Search

The sex chromosomes of the Iberian marbled newt, Triturus marmoratus, were studied using various banding techniques, including restriction enzyme\\/nick translation (RE\\/NT) procedures. Four types of heterochromatin on the sex chromosomes could be distinguished: (1) distamycin A\\/DAPI and chromomycin A3\\/distamycin A positive, EcoRI\\/NT negative, and HaeIII\\/N&Ypsilon; and HinfI\\/NT positive; (2) distamycin A\\/DAPI and chromomycin A3\\/distamycin A positive, but RE\\/NT negative; (3)

P. Herrero; J de la Torre; J. Gosálvez; A. T. Sumner

1992-01-01

133

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

PubMed

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

Kejnovsky, E; Vyskot, B

2010-07-01

134

A sex-chromosome mutation in Silene latifolia.  

PubMed

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

Miller, Paige M; Kesseli, Richard V

2011-09-01

135

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. PMID:22869747

Wang, Jianping; Na, Jong-Kuk; Yu, Qingyi; Gschwend, Andrea R.; Han, Jennifer; Zeng, Fanchang; Aryal, Rishi; VanBuren, Robert; Murray, Jan E.; Zhang, Wenli; Navajas-Pérez, 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

136

Chromosomal Abnormalities Chromosomal abnormalities  

E-print Network

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

Dellaire, Graham

137

A case of subfertile cow with structural abnormalities of the X-chromosome  

E-print Network

Note A case of subfertile cow with structural abnormalities of the X-chromosome H. HANADA S years old Japanese Black, cow, which had been slaughtered due to subfertility. Structural chromosome deletions affected more specifically the X-chromosome. The frequency was significantly higher than

Paris-Sud XI, Université de

138

The Staurotypus Turtles and Aves Share the Same Origin of Sex Chromosomes but Evolved Different Types of Heterogametic Sex Determination  

PubMed Central

Reptiles have a wide diversity of sex-determining mechanisms and types of sex chromosomes. Turtles exhibit temperature-dependent sex determination and genotypic sex determination, with male heterogametic (XX/XY) and female heterogametic (ZZ/ZW) sex chromosomes. Identification of sex chromosomes in many turtle species and their comparative genomic analysis are of great significance to understand the evolutionary processes of sex determination and sex chromosome differentiation in Testudines. The Mexican giant musk turtle (Staurotypus triporcatus, Kinosternidae, Testudines) and the giant musk turtle (Staurotypus salvinii) have heteromorphic XY sex chromosomes with a low degree of morphological differentiation; however, their origin and linkage group are still unknown. Cross-species chromosome painting with chromosome-specific DNA from Chinese soft-shelled turtle (Pelodiscus sinensis) revealed that the X and Y chromosomes of S. triporcatus have homology with P. sinensis chromosome 6, which corresponds to the chicken Z chromosome. We cloned cDNA fragments of S. triporcatus homologs of 16 chicken Z-linked genes and mapped them to S. triporcatus and S. salvinii chromosomes using fluorescence in situ hybridization. Sixteen genes were localized to the X and Y long arms in the same order in both species. The orders were also almost the same as those of the ostrich (Struthio camelus) Z chromosome, which retains the primitive state of the avian ancestral Z chromosome. These results strongly suggest that the X and Y chromosomes of Staurotypus turtles are at a very early stage of sex chromosome differentiation, and that these chromosomes and the avian ZW chromosomes share the same origin. Nonetheless, the turtles and birds acquired different systems of heterogametic sex determination during their evolution. PMID:25121779

Kawagoshi, Taiki; Uno, Yoshinobu; Nishida, Chizuko; Matsuda, Yoichi

2014-01-01

139

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

Microsoft Academic Search

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

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

2006-01-01

140

INVESTIGATION Meiotic Sex Chromosome Inactivation Is Disrupted  

E-print Network

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. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes

Dean, Matthew D.

141

THE CONTRIBUTION OF FEMALE MEIOTIC DRIVE TO THE EVOLUTION OF NEO-SEX CHROMOSOMES  

PubMed Central

Sex chromosomes undergo rapid turnover in certain taxonomic groups. One of the mechanisms of sex chromosome turnover involves fusions between sex chromosomes and autosomes. Sexual antagonism, heterozygote advantage, and genetic drift have been proposed as the drivers for the fixation of this evolutionary event. However, all empirical patterns of the prevalence of multiple sex chromosome systems across different taxa cannot be simply explained by these three mechanisms. In this study, we propose that female meiotic drive may contribute to the evolution of neo-sex chromosomes. The results of this study showed that in mammals, the XY1Y2 sex chromosome system is more prevalent in species with karyotypes of more biarmed chromosomes, whereas the X1X2Y sex chromosome system is more prevalent in species with predominantly acrocentric chromosomes. In species where biarmed chromosomes are favored by female meiotic drive, X-autosome fusions (XY1Y2 sex chromosome system) will be also favored by female meiotic drive. In contrast, in species with more acrocentric chromosomes, Y-autosome fusions (X1X2Y sex chromosome system) will be favored just because of the biased mutation rate toward chromosomal fusions. Further consideration should be given to female meiotic drive as a mechanism in the fixation of neo-sex chromosomes. PMID:23025609

Yoshida, Kohta; Kitano, Jun

2012-01-01

142

Increased prevalence of sex chromosome aneuploidies in specific language impairment and dyslexia  

PubMed Central

Aim Sex chromosome aneuploidies increase the risk of spoken or written language disorders but individuals with specific language impairment (SLI) or dyslexia do not routinely undergo cytogenetic analysis. We assess the frequency of sex chromosome aneuploidies in individuals with language impairment or dyslexia. Method Genome-wide single nucleotide polymorphism genotyping was performed in three sample sets: a clinical cohort of individuals with speech and language deficits (87 probands: 61 males, 26 females; age range 4 to 23 years), a replication cohort of individuals with SLI, from both clinical and epidemiological samples (209 probands: 139 males, 70 females; age range 4 to 17 years), and a set of individuals with dyslexia (314 probands: 224 males, 90 females; age range 7 to 18 years). Results In the clinical language-impaired cohort, three abnormal karyotypic results were identified in probands (proband yield 3.4%). In the SLI replication cohort, six abnormalities were identified providing a consistent proband yield (2.9%). In the sample of individuals with dyslexia, two sex chromosome aneuploidies were found giving a lower proband yield of 0.6%. In total, two XYY, four XXY (Klinefelter syndrome), three XXX, one XO (Turner syndrome), and one unresolved karyotype were identified. Interpretation The frequency of sex chromosome aneuploidies within each of the three cohorts was increased over the expected population frequency (approximately 0.25%) suggesting that genetic testing may prove worthwhile for individuals with language and literacy problems and normal non-verbal IQ. Early detection of these aneuploidies can provide information and direct the appropriate management for individuals. PMID:24117048

Simpson, Nuala H; Addis, Laura; Brandler, William M; Slonims, Vicky; Clark, Ann; Watson, Jocelynne; Scerri, Thomas S; Hennessy, Elizabeth R; Bolton, Patrick F; Conti-Ramsden, Gina; Fairfax, Benjamin P; Knight, Julian C; Stein, John; Talcott, Joel B; O'Hare, Anne; Baird, Gillian; Paracchini, Silvia; Fisher, Simon E; Newbury, Dianne F; Consortium, SLI

2014-01-01

143

Sexually Antagonistic “Zygotic Drive” of the Sex Chromosomes  

Microsoft Academic Search

Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs

William R. Rice; Sergey Gavrilets; Urban Friberg

2008-01-01

144

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

PubMed

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. PMID:24422881

Silkaitis, Katherine; Lemos, Bernardo

2014-01-01

145

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. PMID:24422881

2014-01-01

146

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. PMID:24145389

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

2013-01-01

147

Chromosomal abnormalities and hormonal disorders of primary amenorrhea patients in Egypt  

PubMed Central

BACKGROUND: Primary amenorrhea is defined as the absence of menstruation and secondary sexual characteristics in phenotypic women aged 14 years or older. Hormonal disorders are main causes of primary amenorrhea. Common hormonal cause of primary amenorrhea includes pituitary dysfunction and absent ovarian function. The aim of this study was to estimate the incidence and types of chromosomal abnormalities in patients with primary amenorrhea in Egypt. MATERIALS AND METHODS: Chromosomal analysis and hormonal assay were carried out on 223 patients with primary amenorrhea that were referred from different parts of Egypt to Cytogenetic laboratory of Genetic Unit, Children Hospital Mansoura University, from July 2008 to December 2010. FISH technique was carried out in some of cases to more evaluation. RESULTS: The frequency of chromosomal abnormalities was 46 (20.63%) in primary amenorrhea patients. The chromosomal abnormalities can be classified into four main types. (1) The numerical abnormalities of the X?chromosome were detected in 23 (50 %). (2) Structural abnormalities of the X chromosome were detected in 11 (23.91%). (3) Mosaicism of X chromosome was found in 10 (21.74%). (4) Male karyotype 46, XY was presented in 2 (4.35%). CONCLUSION: The present study showed that karyotype and FISH are necessary to detect the causes of primary amenorrhea. This study also revealed the incidence of chromosomal abnormalities in women with primary amenorrhea in Egypt is similar to that reported in previous literatures. PMID:23162293

El-Dahtory, Faeza

2012-01-01

148

Structural brain imaging abnormalities associated with schizophrenia and partial trisomy of chromosome 5  

PubMed Central

SYNOPSIS Chromosomal abnormalities occurring in association with mental illness provide a unique opportunity to study the interaction of genetic abnormalities and the brain in mental illness. Four individuals from a family in which schizophrenia was found to cosegregate with a partial trisomy of chromosome 5 were studied with computed tomography and magnetic resonance imaging. Temporal lobe atrophy was found in the two trisomic males and in the asymptomatic balanced translocation female. In addition, a large cavum septum pellucidum and a cavum vergae were found in the older trisomic individual. Scans from the normal male were free of abnormalities. These results suggest that molecular studies of the translocation breakpoints in this chromosomal abnormality may be of interest, and encourage further studies of brain structure in other chromosomal abnormalities associated with psychosis. PMID:1615118

HONER, WILLIAM G.; BASSETT, ANNE S.; MacEWAN, G. WILLIAM; HURWITZ, TREVOR; LI, DAVID K.B.; HILAL, SADEK; PROHOVNIK, ISAK

2011-01-01

149

Structural brain imaging abnormalities associated with schizophrenia and partial trisomy of chromosome 5.  

PubMed

Chromosomal abnormalities occurring in association with mental illness provide a unique opportunity to study the interaction of genetic abnormalities and the brain in mental illness. Four individuals from a family in which schizophrenia was found to cosegregate with a partial trisomy of chromosome 5 were studied with computed tomography and magnetic resonance imaging. Temporal lobe atrophy was found in the two trisomic males and in the asymptomatic balanced translocation female. In addition, a large cavum septum pellucidum and a cavum vergae were found in the older trisomic individual. Scans from the normal male were free of abnormalities. These results suggest that molecular studies of the translocation breakpoints in this chromosomal abnormality may be of interest, and encourage further studies of brain structure in other chromosomal abnormalities associated with psychosis. PMID:1615118

Honer, W G; Bassett, A S; MacEwan, G W; Hurwitz, T; Li, D K; Hilal, S; Prohovnik, I

1992-05-01

150

Early stages of sex chromosome differentiation in fish as analysed by simple repetitive DNA sequences  

Microsoft Academic Search

Animal sex chromosome evolution has started on different occasions with a homologous pair of autosomes leading to morphologically differentiated gonosomes. In contrast to other vertebrate classes, among fishes cytologically demonstrable sex chromosomes are rare. In reptiles, certain motifs of simple tandemly repeated DNA sequences like (gata)n\\/(gaca)m are associated with the constitutive heterochromatin of sex chromosomes. In this study a panel

Indrajit Nanda; Manfred Schartl; Wolfgang Feichtinger; Jörg T. Epplen; Michael Schmid

1992-01-01

151

Nonrandom Representation of Sex-Biased Genes on Chicken Z Chromosome R. Storchova , P. Divina  

E-print Network

Nonrandom Representation of Sex-Biased Genes on Chicken Z Chromosome R. Storchova´ , P. Divina chromosome of various animal species has an unusual complement of genes with sex-biased or sex-specific expression. However, the study of the X chromosome gene content in different organisms provided conflict- ing

Storchová, Radka

152

Identification of Cryptic Sex Chromosomes and Isolation of X-and Y-Borne Genes  

E-print Network

15 Identification of Cryptic Sex Chromosomes and Isolation of X- and Y-Borne Genes Paul D. Waters chromosomes. We have adapted cell culture and molecular cytogenetic techniques to study the sex chromosomes of many exotic mammals, birds, and reptiles. Here we describe differential chromosome banding and staining

Canberra, University of

153

Insect sex chromosomes. VI. A presumptive hyperactivation of the male X chromosome in Acheta domesticus (L.).  

PubMed

The functional status of the X chromosome in Acheta domesticus has been analysed at the whole chromosome level on the basis of (1) 3H-thymidine autoradiography, (2) 5-BrdU/AO fluorescence microscopy (3) in vivo 5-BrdU incorporation and (4) 3H-UdR induced aberrations. The rationale of these techniques in relation to the functional aspect of the X chromosome is that the inactive X chromosome would (1) show asynchrony in DNA synthesis, (2) show differential fluorescence, (3) respond differentially to in vivo 5-BrdU treatment and (4) the active X chromosome would show aberrations when treated with 3H-Uridine. From the results, it appears that the X chromosomes in both male (XO) and female (XX) somatic cells of Acheta are euchromatic (active). Further, the single X in the male is transcriptionally as active as the two X chromosomes in the female. In other words, the single X in the male is hyperactive when compared with the single X in the female. From this it is inferred that the male X chromosome is differentially regulated in order to bring about an equalization of it's gene product(s) to that produced by both Xs in the female. Drosophila melanogaster has a comparable system of dosage compensation. Thus, Acheta is yet another insect showing evidence for an X chromosome regulatory mechanism of dosage compensation. Additionally, it is surmised that sex determination in Acheta is based on an autosomes/X chromosome balance mechanism. PMID:7172864

Rao, S R; Ali, S

1982-01-01

154

Sex-chromosome differentiation and 'sex races' in the common frog (Rana temporaria).  

PubMed

Sex-chromosome differentiation was recently shown to vary among common frog populations in Fennoscandia, suggesting a trend of increased differentiation with latitude. By rearing families from two contrasted populations (respectively, from northern and southern Sweden), we show this disparity to stem from differences in sex-determination mechanisms rather than in XY-recombination patterns. Offspring from the northern population display equal sex ratios at metamorphosis, with phenotypic sexes that correlate strongly with paternal LG2 haplotypes (the sex chromosome); accordingly, Y haplotypes are markedly differentiated, with male-specific alleles and depressed diversity testifying to their smaller effective population size. In the southern population, by contrast, a majority of juveniles present ovaries at metamorphosis; only later in development do sex ratios return to equilibrium. Even at these later stages, phenotypic sexes correlate only mildly with paternal LG2 haplotypes; accordingly, there are no recognizable Y haplotypes. These distinct patterns of gonadal development fit the concept of 'sex races' proposed in the 1930s, with our two populations assigned to the 'differentiated' and 'semi-differentiated' races, respectively. Our results support the suggestion that 'sex races' differ in the genetic versus epigenetic components of sex determination. Analysing populations from the 'undifferentiated race' with high-density genetic maps should help to further test this hypothesis. PMID:25833852

Rodrigues, Nicolas; Vuille, Yvan; Loman, Jon; Perrin, Nicolas

2015-05-01

155

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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. However, we are now just beginning to gain insight into the initial stages of sex chromosome evolution vi...

156

Mouse model systems to study sex chromosome genes and behavior: relevance to humans.  

PubMed

Sex chromosome genes directly influence sex differences in behavior. The discovery of the Sry gene on the Y chromosome (Gubbay et al., 1990; Koopman et al., 1990) substantiated the sex chromosome mechanistic link to sex differences. Moreover, the pronounced connection between X chromosome gene mutations and mental illness produces a strong sex bias in these diseases. Yet, the dominant explanation for sex differences continues to be the gonadal hormones. Here we review progress made on behavioral differences in mouse models that uncouple sex chromosome complement from gonadal sex. We conclude that many social and cognitive behaviors are modified by sex chromosome complement, and discuss the implications for human research. Future directions need to include identification of the genes involved and interactions with these genes and gonadal hormones. PMID:24388960

Cox, Kimberly H; Bonthuis, Paul J; Rissman, Emilie F

2014-10-01

157

Sex chromosome evolution in fish: the formation of the neo-Y chromosome in Eigenmannia (Gymnotiformes)  

Microsoft Academic Search

.   Chromosomes of a species of Eigenmannia presenting a X1X1X2X2:X1X2Y sex chromosome system, resulting from a Y-autosome Robertsonian translocation, were analyzed using the C-banding technique,\\u000a chromomycin A3 (CMA3) and mithramycin (MM) staining and in situ digestion by the restriction endonuclease AluI. A comparison of the metacentric Y chromosome of males with the corresponding acrocentrics in females indicated that a C-band-positive,

L. F. Almeida-Toledo; F. Foresti; M. F. Z. Daniel; S. A. Toledo-Filho

2000-01-01

158

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. PMID:24130752

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

2013-01-01

159

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

PubMed

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. PMID:17395720

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

2007-04-10

160

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

161

Deficit of mitonuclear genes on the human X chromosome predates sex chromosome formation.  

PubMed

Two taxa studied to date, the therian mammals and Caenorhabditis elegans, display underrepresentations of mitonuclear genes (mt-N genes, nuclear genes whose products are imported to and act within the mitochondria) on their X chromosomes. This pattern has been interpreted as the result of sexual conflict driving mt-N genes off of the X chromosome. However, studies in several other species have failed to detect a convergent biased distribution of sex-linked mt-N genes, leading to questions over the generality of the role of sexual conflict in shaping the distribution of mt-N genes. Here we tested whether mt-N genes moved off of the therian X chromosome following sex chromosome formation, consistent with the role of sexual conflict, or whether the paucity of mt-N genes on the therian X is a chance result of an underrepresentation on the ancestral regions that formed the X chromosome. We used a synteny-based approach to identify the ancestral regions in the platypus and chicken genomes that later formed the therian X chromosome. We then quantified the movement of mt-N genes on and off of the X chromosome and the distribution of mt-N genes on the human X and ancestral X regions. We failed to find an excess of mt-N gene movement off of the X. The bias of mt-N genes on ancestral therian X chromosomes was also not significantly different from the biases on the human X. Together our results suggest that, rather than conflict driving mt-N genes off of the mammalian X, random biases on chromosomes that formed the X chromosome could explain the paucity of mt-N genes in the therian lineage. PMID:25637223

Dean, Rebecca; Zimmer, Fabian; Mank, Judith E

2015-02-01

162

Deficit of Mitonuclear Genes on the Human X Chromosome Predates Sex Chromosome Formation  

PubMed Central

Two taxa studied to date, the therian mammals and Caenorhabditis elegans, display underrepresentations of mitonuclear genes (mt-N genes, nuclear genes whose products are imported to and act within the mitochondria) on their X chromosomes. This pattern has been interpreted as the result of sexual conflict driving mt-N genes off of the X chromosome. However, studies in several other species have failed to detect a convergent biased distribution of sex-linked mt-N genes, leading to questions over the generality of the role of sexual conflict in shaping the distribution of mt-N genes. Here we tested whether mt-N genes moved off of the therian X chromosome following sex chromosome formation, consistent with the role of sexual conflict, or whether the paucity of mt-N genes on the therian X is a chance result of an underrepresentation on the ancestral regions that formed the X chromosome. We used a synteny-based approach to identify the ancestral regions in the platypus and chicken genomes that later formed the therian X chromosome. We then quantified the movement of mt-N genes on and off of the X chromosome and the distribution of mt-N genes on the human X and ancestral X regions. We failed to find an excess of mt-N gene movement off of the X. The bias of mt-N genes on ancestral therian X chromosomes was also not significantly different from the biases on the human X. Together our results suggest that, rather than conflict driving mt-N genes off of the mammalian X, random biases on chromosomes that formed the X chromosome could explain the paucity of mt-N genes in the therian lineage. PMID:25637223

Dean, Rebecca; Zimmer, Fabian; Mank, Judith E.

2015-01-01

163

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. PMID:24015111

Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

2013-01-01

164

The advantages of using triple-marker screening for chromosomal abnormalities  

Microsoft Academic Search

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

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

1995-01-01

165

Evolutionary strata on the chicken Z chromosome: implications for sex chromosome evolution.  

PubMed Central

The human X chromosome exhibits four "evolutionary strata," interpreted to represent distinct steps in the process whereby recombination became arrested between the proto X and proto Y. To test if this is a general feature of sex chromosome evolution, we studied the Z-W sex chromosomes of birds, which have female rather than male heterogamety and evolved from a different autosome pair than the mammalian X and Y. Here we analyze all five known gametologous Z-W gene pairs to investigate the "strata" hypothesis in birds. Comparisons of the rates of synonymous substitution and intronic divergence between Z and W gametologs reveal the presence of at least two evolutionary strata spread over the p and q arms of the chicken Z chromosome. A phylogenetic analysis of intronic sequence data from different avian lineages indicates that Z-W recombination ceased in the oldest stratum (on Zq; CHD1Z, HINTZ, and SPINZ) 102-170 million years ago (MYA), before the split of the Neoaves and Eoaves. However, recombination continued in the second stratum (on Zp; UBAP2Z and ATP5A1Z) until after the divergence of extant avian orders, with Z and W diverging 58-85 MYA. Our data suggest that progressive and stepwise cessation of recombination is a general feature behind sex chromosome evolution. PMID:15166161

Handley, Lori-Jayne Lawson; Ceplitis, Helene; Ellegren, Hans

2004-01-01

166

Increased number of sex chromosomes affects height in a nonlinear fashion: a study of 305 patients with sex chromosome aneuploidy.  

PubMed

Tall stature and eunuchoid body proportions characterize patients with 47,XXY Klinefelter syndrome, whereas patients with 45,X Turner syndrome are characterized by impaired growth. Growth is relatively well characterized in these two syndromes, while few studies describe the growth of patients with higher grade sex chromosome aneuploidies. It has been proposed that tall stature in sex chromosome aneuploidy is related to an overexpression of SHOX, although the copy number of SHOX has not been evaluated in previous studies. Our aims were therefore: (1) to assess stature in 305 patients with sex chromosome aneuploidy and (2) to determine the number of SHOX copies in a subgroup of these patients (n = 255) these patients and 74 healthy controls. Median height standard deviation scores in 46,XX males (n = 6) were -1.2 (-2.8 to 0.3), +0.9 (-2.2 to +4.6) in 47,XXY (n = 129), +1.3 (-1.8 to +4.9) in 47,XYY (n = 44), +1.1 (-1.9 to +3.4) in 48,XXYY (n = 45), +1.8 (-2.0 to +3.2) in 48,XXXY (n = 9), and -1.8 (-4.2 to -0.1) in 49,XXXXY (n = 10). Median height standard deviation scores in patients with 45,X (n = 6) were -2.6 (-4.1 to -1.6), +0.7 (-0.9 to +3.2) in 47,XXX (n = 40), -0.6 (-1.9 to +2.1) in 48,XXXX (n = 13), and -1.0 (-3.5 to -0.8) in 49,XXXXX (n = 3). Height increased with an increasing number of extra X or Y chromosomes, except in males with five, and in females with four or five sex chromosomes, consistent with a nonlinear effect on height. PMID:20425825

Ottesen, Anne Marie; Aksglaede, Lise; Garn, Inger; Tartaglia, Nicole; Tassone, Flora; Gravholt, Claus H; Bojesen, Anders; Sørensen, Kaspar; Jørgensen, Niels; Rajpert-De Meyts, Ewa; Gerdes, Tommy; Lind, Anne-Marie; Kjaergaard, Susanne; Juul, Anders

2010-05-01

167

Sex differences in ischemic stroke sensitivity are influenced by gonadal hormones, not by sex chromosome complement.  

PubMed

Epidemiologic studies have shown sex differences in ischemic stroke. The four core genotype (FCG) mouse model, in which the testes determining gene, Sry, has been moved from Y chromosome to an autosome, was used to dissociate the effects of sex hormones from sex chromosome in ischemic stroke outcome. Middle cerebral artery occlusion (MCAO) in gonad intact FCG mice revealed that gonadal males (XXM and XYM) had significantly higher infarct volumes as compared with gonadal females (XXF and XYF). Serum testosterone levels were equivalent in adult XXM and XYM, as was serum estrogen in XXF and XYF mice. To remove the effects of gonadal hormones, gonadectomized FCG mice were subjected to MCAO. Gonadectomy significantly increased infarct volumes in females, while no change was seen in gonadectomized males, indicating that estrogen loss increases ischemic sensitivity. Estradiol supplementation in gonadectomized FCG mice rescued this phenotype. Interestingly, FCG male mice were less sensitive to effects of hormones. This may be due to enhanced expression of the transgene Sry in brains of FCG male mice. Sex differences in ischemic stroke sensitivity appear to be shaped by organizational and activational effects of sex hormones, rather than sex chromosomal complement. PMID:25388681

Manwani, Bharti; Bentivegna, Kathryn; Benashski, Sharon E; Venna, Venugopal Reddy; Xu, Yan; Arnold, Arthur P; McCullough, Louise D

2015-02-01

168

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. PMID:22568889

2012-01-01

169

Agenesis of the lung associated with a chromosome abnormality (46,XX,2p+)  

Microsoft Academic Search

We describe a patient with agenesis of the left lung who also had a chromosome abnormality, probably representing a duplication of the distal part of the upper arm of chromosome 2. In addition to this finding, the existence of familial cases of lung agenesis indicate that further studies are required for better understanding of the genetic aspects of this condition.

B Say; N J Carpenter; G Giacoia; S Jegathesan

1980-01-01

170

Copyright 2004 by the Genetics Society of America Evolutionary Strata on the Chicken Z Chromosome: Implications for Sex  

E-print Network

differentiation of as mammals, birds, fish, insects, and plants and have the proto-sex chromosomes can begin only: Implications for Sex Chromosome Evolution Lori-Jayne Lawson Handley,1 Helene Ceplitis and Hans Ellegren2 feature of sex chromosome evolution, we studied the Z-W sex chromosomes of birds, which have female rather

Alvarez, Nadir

171

The role of sex chromosomes in sexual dimorphism: discordance between molecular and phenotypic data.  

PubMed

In addition to initial sex determination, genes on the sex chromosomes are theorized to play a particularly important role in phenotypic differences between males and females. Sex chromosomes in many species display molecular signatures consistent with these theoretical predictions, particularly through sex-specific gene expression. However, the phenotypic implications of this molecular signature are unresolved, and the role of the sex chromosomes in quantitative genetic studies of phenotypic sex differences is largely equivocal. In this article, we examine molecular and phenotypic data in the light of theoretical predictions about masculinization and feminization of the sex chromosomes. Additionally, we discuss the role of genetic and regulatory complexities in the genome–phenotype relationship, and ultimately how these affect the overall role of the sex chromosomes in sex differences. PMID:25105198

Dean, R; Mank, J E

2014-07-01

172

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. PMID:22248351

2012-01-01

173

Tracking the evolution of sex chromosome systems in Melanoplinae grasshoppers through chromosomal mapping of repetitive DNA sequences  

PubMed Central

Background The accumulation of repetitive DNA during sex chromosome differentiation is a common feature of many eukaryotes and becomes more evident after recombination has been restricted or abolished. The accumulated repetitive sequences include multigene families, microsatellites, satellite DNAs and mobile elements, all of which are important for the structural remodeling of heterochromatin. In grasshoppers, derived sex chromosome systems, such as neo-XY?/XX? and neo-X1X2Y?/X1X1X2X2?, are frequently observed in the Melanoplinae subfamily. However, no studies concerning the evolution of sex chromosomes in Melanoplinae have addressed the role of the repetitive DNA sequences. To further investigate the evolution of sex chromosomes in grasshoppers, we used classical cytogenetic and FISH analyses to examine the repetitive DNA sequences in six phylogenetically related Melanoplinae species with X0?/XX?, neo-XY?/XX? and neo-X1X2Y?/X1X1X2X2? sex chromosome systems. Results Our data indicate a non-spreading of heterochromatic blocks and pool of repetitive DNAs (C0t-1 DNA) in the sex chromosomes; however, the spreading of multigene families among the neo-sex chromosomes of Eurotettix and Dichromatos was remarkable, particularly for 5S rDNA. In autosomes, FISH mapping of multigene families revealed distinct patterns of chromosomal organization at the intra- and intergenomic levels. Conclusions These results suggest a common origin and subsequent differential accumulation of repetitive DNAs in the sex chromosomes of Dichromatos and an independent origin of the sex chromosomes of the neo-XY and neo-X1X2Y systems. Our data indicate a possible role for repetitive DNAs in the diversification of sex chromosome systems in grasshoppers. PMID:23937327

2013-01-01

174

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.

175

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

PubMed

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

Bergero, Roberta; Charlesworth, Deborah

2011-09-13

176

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

PubMed Central

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

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

2014-01-01

177

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

Microsoft Academic Search

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

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

2007-01-01

178

Sex chromosome synapsis and recombination in male guppies.  

PubMed

Guppy X and Y chromosomes represent an early stage in sex chromosome divergence. Synapsis and recombination between X and Y chromosomes attract special attention because recombination suppression promotes their differentiation, but previous studies have given contradictory results. Linkage analysis indicated that recombination between X and Y was extremely rare (<10%) and occurred in the medial part of the Y chromosome, while cytological analysis demonstrated regular association between the distal ends of the X and Y at diakinesis. In this study, we examine pairing and recombination between X and Y chromosomes using immunolocalization of MLH1 to mark recombination nodules, and genomic in situ hybridization with a male DNA probe to identify the Y-specific heterochromatic region. Pairing between X and Y is initiated distally. Single crossovers were detected in 87% of XY synaptonemal complexes, most often in the distal region and less frequently in a median position indicating that end-to-end associations between X and Y are chiasmatic. Thus, we suggest that the very low frequency of recombination detected by linkage analysis in a previous study resulted from a lack of informative markers in distal regions. PMID:25608108

Lisachov, Artem P; Zadesenets, Kira S; Rubtsov, Nikolay B; Borodin, Pavel M

2015-04-01

179

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

PubMed Central

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

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

2015-01-01

180

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

PubMed

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

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

2015-01-01

181

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

PubMed

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

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

2013-10-01

182

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

PubMed Central

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

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

2013-01-01

183

On the maintenance of sex chromosome polymorphism by sex-antagonistic selection.  

PubMed

Complex sex determination systems are a priori unstable and require specific selective forces for their maintenance. Analytical derivations suggest that sex antagonistic selection may play such a role, but this assumes absence of recombination between the sex-determining and sex-antagonistic genes. Using individual-based simulations and focusing on the sex chromosome and coloration polymorphisms of platy fishes as a case study, we show that the conditions for polymorphism maintenance induce female biases in primary sex ratios, so that sex ratio selection makes the system collapse toward male or female heterogamety as soon as recombinant genotypes appear. However, a polymorphism can still be maintained under scenarios comprising strong sexual selection against dull males, mild natural selection against bright females, and low recombination rates. Though such conditions are plausibly met in natural populations of fishes harboring such polymorphisms, quantitative empirical evaluations are required to properly test whether sex antagonistic selection is a causal agent or whether other selective processes are required (such as local mate competition favoring female-biased sex ratios). PMID:21956029

Blaser, Olivier; Neuenschwander, Samuel; Perrin, Nicolas

2011-10-01

184

Dosage compensation, the origin and the afterlife of sex chromosomes Jan Larsson1  

E-print Network

. A fascinating aspect of evolution is the differentiation of sex chromosomes. Organisms with highly differentiated sex chromosomes, such as the mammalian X and Y, must compensate for the imbalance in gene dosage of evolutionary forces on sex chromo- some differentiation is particularly apparent in the mammalian

Meller, Victoria

185

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

PubMed

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

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

2014-01-01

186

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

E-print Network

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

Paris-Sud XI, Université de

187

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

E-print Network

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

Dean, Matthew D.

188

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

Microsoft Academic Search

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

Dmitry A. Filatov

2005-01-01

189

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

PubMed

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

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

2012-01-01

190

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

Microsoft Academic Search

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

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

191

Genomic Characterization of Prenatally Detected Chromosomal Structural Abnormalities Using Oligonucleotide Array Comparative Genomic Hybridization  

PubMed Central

Detection of chromosomal structural abnormalities using conventional cytogenetic methods poses a challenge for prenatal genetic counseling due to unpredictable clinical outcomes and risk of recurrence. Of the 1,726 prenatal cases in a 3-year period, we performed oligonucleotide array comparative genomic hybridization (aCGH) analysis on 11 cases detected with various structural chromosomal abnormalities. In nine cases, genomic aberrations and gene contents involving a 3p distal deletion, a marker chromosome from chromosome 4, a derivative chromosome 5 from a 5p/7q translocation, a de novo distal 6q deletion, a recombinant chromosome 8 comprised of an 8p duplication and an 8q deletion, an extra derivative chromosome 9 from an 8p/9q translocation, mosaicism for chromosome 12q with added material of initially unknown origin, an unbalanced 13q/15q rearrangement, and a distal 18q duplication and deletion were delineated. An absence of pathogenic copy number changes was noted in one case with a de novo 11q/14q translocation and in another with a familial insertion of 21q into a 19q. Genomic characterization of the structural abnormalities aided in the prediction of clinical outcomes. These results demonstrated the value of aCGH analysis in prenatal cases with subtle or complex chromosomal rearrangements. Furthermore, a retrospective analysis of clinical indications of our prenatal cases showed that approximately 20% of them had abnormal ultrasound findings and should be considered as high risk pregnancies for a combined chromosome and aCGH analysis. PMID:21671377

Li, Peining; Pomianowski, Pawel; DiMaio, Miriam S.; Florio, Joanne R.; Rossi, Michael R.; Xiang, Bixia; Xu, Fang; Yang, Hui; Geng, Qian; Xie, Jiansheng; Mahoney, Maurice J.

2013-01-01

192

Environmental exposure to pyrethroids and sperm sex chromosome disomy: a cross-sectional study  

PubMed Central

Background The role of environmental pesticide exposures, such as pyrethroids, and their relationship to sperm abnormalities are not well understood. This study investigated whether environmental exposure to pyrethroids was associated with altered frequency of sperm sex chromosome disomy in adult men. Methods A sample of 75 subjects recruited through a Massachusetts infertility clinic provided urine and semen samples. Individual exposures were measured as urinary concentrations of three pyrethroid metabolites ((3-phenoxybenzoic acid (3PBA), cis- and trans- 3-(2,2-Dichlorovinyl)-1-methylcyclopropane-1,2-dicarboxylic acid (CDCCA and TDCCA)). Multiprobe fluorescence in situ hybridization for chromosomes X, Y, and 18 was used to determine XX, YY, XY, 1818, and total sex chromosome disomy in sperm nuclei. Poisson regression analysis was used to examine the association between aneuploidy rates and pyrethroid metabolites while adjusting for covariates. Results Between 25-56% of the sample were above the limit of detection (LOD) for the pyrethroid metabolites. All sex chromosome disomies were increased by 7-30% when comparing men with CDCCA and TDCCA levels above the LOD to those below the LOD. For 3PBA, compared to those below the LOD, those above the LOD had YY18 disomy rates 1.28 times higher (95% CI: 1.15, 1.42) whereas a reduced rate was seen for XY18 and total disomy (IRR?=?0.82; 95% CI: 0.77, 0.87; IRR?=?0.93; 95% CI: 0.87-0.97), and no association was seen for XX18 and 1818. Conclusions Our findings suggest that urinary concentrations of CDCCA and TDCCA above the LOD were associated with increased rates of aneuploidy. However the findings for 3BPA were not consistent. This is the first study to examine these relationships, and replication of our findings is needed before the association between pyrethroid metabolites and aneuploidy can be fully defined. PMID:24345058

2013-01-01

193

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. PMID:23439698

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

2013-01-01

194

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

E-print Network

five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome. In order to investigate monotreme sex chromosome evolution, we performed a comparative study of platypus and echidna by chromosome painting and comparative gene mapping. Results...

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

2007-11-16

195

Chromosomal abnormalities in neutron-induced acute myeloid leukemias in CBA/H mice  

SciTech Connect

Acute myeloid leukemias (AMLs) induced in CBA/H mice by 1 MeV fission neutrons have been examined for chromosomal abnormalities by G-band analysis. In common with X-ray- and {alpha}-particle-induced AMLs in CBA/H mice, more than 90% (16/17) of the myeloid leukemias had chromosome 2 abnormalities, in this case, all interstitial deletions. Chromosome 2 breakpoints were not wholly consistent, but clustering in three specific G-band regions was observed. Very distal (H-region) breakpoints were more common in the neutron AMLs than in X-ray- or {alpha}-particle-induced leukemias. These data indicate that neutron-induced AMLs in CBA/H mice are not characterized by a specific chromosome deletion but that a variety of chromosome 2 deletion types are associated with the disease. Trisomy of chromosome 1 (12.5% AMLs) and aneusomy of chromosomes 6 (31% AMLs) and Y (37.5% AMLs) were noted. While chromatid breakage was observed occasionally in neutron-induced AML, no clear indications of persistent chromosomal instability or high levels of stable chromosomal change were apparent. 19 refs., 1 fig., 1 tab.

Bouffler, S.D. [National Radiological Protection Board, Oxon (United Kingdom); Meijne, E.I.M.; Huiskamp, R. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands)] [and others

1996-09-01

196

Sex differences in juvenile mouse social behavior are influenced by sex chromosomes and social context.  

PubMed

Play behavior in juvenile primates, rats and other species is sexually dimorphic, with males showing more play than females. In mice, sex differences in juvenile play have only been examined in out-bred CD-1 mice. In this strain, contrary to other animals, male mice display less play soliciting than females. Using an established same-sex dyadic interaction test, we examined play in in-bred C57BL/6J (B6) 21-day-old mice. When paired with non-siblings, males tended to be more social than females, spending more time exploring the test cage. Females displayed significantly more anogenital sniffing and solicited play more frequently than did males. To determine if the origin of the sex difference was sex chromosome genes or gonadal sex, next we used the four core genotype mouse. We found significant interactions between gonadal sex and genotype for several behaviors. Finally, we asked if sibling pairs (as compared to non-siblings) would display qualitatively or quantitatively different behavior. In fact, XX females paired with a sibling were more social and less exploratory or investigative, whereas XY males exhibited less investigative and play soliciting behaviors in tests with siblings. Many neurobehavioral disorders, like autism spectrum disorder (ASD), are sexually dimorphic in incidence and patients interact less than normal with other children. Our results suggest that sex chromosome genes interact with gonadal hormones to shape the development of juvenile social behavior, and that social context can drastically alter sex differences. These data may have relevance for understanding the etiology of sexually dimorphic disorders such as ASD. PMID:21414140

Cox, K H; Rissman, E F

2011-06-01

197

INDEPENDENT STRATUM FORMATION ON THE AVIAN SEX CHROMOSOMES REVEALS INTER-CHROMOSOMAL GENE CONVERSION AND PREDOMINANCE OF PURIFYING SELECTION ON THE W CHROMOSOME  

PubMed Central

We used a comparative approach spanning three species and 90 million years to study the evolutionary history of the avian sex chromosomes. Using whole transcriptomes, we assembled the largest cross-species dataset of W-linked coding content to date. Our results show that recombination suppression in large portions of the avian sex chromosomes has evolved independently, and that long-term sex chromosome divergence is consistent with repeated and independent inversions spreading progressively to restrict recombination. In contrast, over short-term periods we observe heterogeneous and locus-specific divergence. We also uncover four instances of gene conversion between both highly diverged and recently evolved gametologs, suggesting a complex mosaic of recombination suppression across the sex chromosomes. Lastly, evidence from 16 gametologs reveal that the W chromosome is evolving with a significant contribution of purifying selection, consistent with previous findings that W-linked genes play an important role in encoding sex-specific fitness. PMID:25066800

Wright, Alison E; Harrison, Peter W; Montgomery, Stephen H; Pointer, Marie A; Mank, Judith E

2014-01-01

198

The dragon lizard Pogona vitticeps has ZZ/ZW micro-sex chromosomes Tariq Ezaz1*, Alexander E. Quinn2  

E-print Network

molecular cytogenetic and differential banding techniques to reveal sex chromosomes in this species conclude that P. vitticeps has differentiated, previously unidentifiable W and Z micro-sex chromosomes of the heterogametic chromosome occurred during sex chromosome differentiation in this species, as is the case in some

Canberra, University of

199

Sex determination in Madagascar geckos of the genus Paroedura (Squamata: Gekkonidae): are differentiated sex chromosomes indeed so evolutionary stable?  

PubMed

Among amniote vertebrates, geckos represent a clade with exceptional variability in sex determination; however, only a minority of species of this highly diverse group has been studied in this respect. Here, we describe for the first time a female heterogamety in the genus Paroedura, the group radiated in Madagascar and adjacent islands. We identified homomorphic ZZ/ZW sex chromosomes with a highly heterochromatic W chromosome in Paroedura masobe, Paroedura oviceps, Paroedura karstophila, Paroedura stumpffi, and Paroedura lohatsara. Comparative genomic hybridization (CGH) revealed that female-specific sequences are greatly amplified in the W chromosome of P. lohatsara and that P. gracilis seems to possess a derived system of multiple sex chromosomes. Contrastingly, neither CGH nor heterochromatin visualization revealed differentiated sex chromosomes in the members of the Paroedura picta-Paroedura bastardi-Paroedura ibityensis clade, which is phylogenetically nested within lineages with a heterochromatic W chromosome. As a sex ratio consistent with genotypic sex determination has been reported in P. picta, it appears that the members of the P. picta-P. bastardi-P. ibityensis clade possess homomorphic, poorly differentiated sex chromosomes and may represent a rare example of evolutionary loss of highly differentiated sex chromosomes. Fluorescent in situ hybridization (FISH) with a telomeric probe revealed a telomere-typical pattern in all species and an accumulation of telomeric sequences in the centromeric region of autosomes in P. stumpffi and P. bastardi. Our study adds important information for the greater understanding of the variability and evolution of sex determination in geckos and demonstrates how the geckos of the genus Paroedura provide an interesting model for studying the evolution of the sex chromosomes. PMID:25056523

Koubová, Martina; Johnson Pokorná, Martina; Rovatsos, Michail; Farka?ová, Klára; Altmanová, Marie; Kratochvíl, Lukáš

2014-12-01

200

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. 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

2014-01-01

201

Chromosome abnormality rate among Iranian patients with idiopathic mental retardation from consanguineous marriages  

PubMed Central

Introduction Mental retardation (MR) has heterogeneous aetiology mostly with genetic causes. Chromosomal aberrations are one of the most common causes of MR. Reports on chromosome abnormality rate among consanguineous families are sparse. In order to identify the chromosome abnormality rate in idiopathic mental retardation from consanguineous marriages, a total of 322 Iranian families with positive family history for MR were investigated in the Genetics Research Center. Material and methods In the majority of families (92%) at least two sibs were affected with MR and none had specific chromosomal syndromes such as Down syndrome. Standard cytogenetic techniques using high resolution GTG banding were carried out on all the patients. Results The overall chromosome abnormality rate contributing to mental retardation was 1.24% (4 cases), which comprised 46,XY,der(18)t(4;18)(q31.1;q23)mat; 45,XY,-21,-22,+der(22)t(21;22)(q21.1;q13.33)mat; 46,XY,rec(2)dup(2p)inv(2)(p25.1q37.3)pat, and 46,XY,der(11)t(10;11)(q25.2;q25)pat. Conclusions Although the most likely genetic cause of mental retardation in patients with consanguineous parents is autosomal recessive, the fact that 1.24% of our patients had chromosomal abnormalities emphasizes the importance of cytogenetic investigation as the first laboratory genetic tests for all MR patients. To our knowledge, this is the first report on the rate of chromosome abnormality among patients with idiopathic mental retardation from consanguineous marriages. PMID:22291774

Behjati, Farkhondeh; Ghasemi Firouzabadi, Saghar; Kahrizi, Kimia; Kariminejad, Roxana; Bagherizadeh, Iman; Ansari, Javad; Fallah, Masoumeh; Mojtahedi, Forough; Darvish, Hossein; Bahrami Monajemi, Gholamreza; Abedini, S. Sedigheh; Jamali, Payman; Mojahedi, Faezeh; Zadeh-Vakili, Azita; Najmabadi, Hossein

2011-01-01

202

Comparative mapping reveals autosomal origin of sex chromosome in octoploid Fragaria virginiana.  

PubMed

Recent evolution of separate sexes in flowering plants provides unparalleled opportunities for understanding the early stages of sex chromosome evolution, including their origin from autosomes. Moreover, the transition from combined to separate sexes can be associated with speciation via polyploidization in angiosperms, suggesting that genome doubling/merger may facilitate sterility mutations required for sex chromosome formation. To gain insight into the origin of sex chromosomes in a polyploid plant, we doubled the simple sequence repeat (SSR) density and increased genome coverage in a genetic map of octoploid Fragaria virginiana, a species purported to have a "proto-sex" chromosome, where limited recombination occurs between 2 linked "loci" carrying the male- and female-sterility mutations. Incorporation of almost 3 times the number of SSR markers into the current map facilitated complete characterization of the F. virginiana proto-sex chromosome, revealing its largely autosomal nature and the location of the sex-determining region toward the distal end. Furthermore, extensive synteny between our genetic map and a map involving diploid hermaphroditic congeners allowed assignment of linkage groups to homeologous groups, identification of the proto-sex chromosome's autosomal homoeolog, and detection of a putative rearrangement near the sex-determining region. Fine mapping and additional comparative work will shed light on the intriguing possibility that rearrangements during polyploidization were involved in the evolution of sex chromosomes in Fragaria. PMID:20421320

Spigler, Rachel B; Lewers, Kim S; Johnson, Anna L; Ashman, Tia-Lynn

2010-01-01

203

A gradient of sex linkage in the pseudoautosomal region of the human sex chromosomes  

Microsoft Academic Search

Three independent pseudoautosomal loci are linked to sex determination at frequencies which define a gradient of linkage. The segregation patterns of these loci indicate that X\\/Y recombination results from a single obligatory meiotic crossing-over in the pseudoautosomal region. Recombination in male germ cells in the terminal regions of the short arms of the X and Y chromosomes is 10-fold greater

François Rouyer; Marie-Christine Simmler; Christophe Johnsson; Gilles Vergnaud; Howard J. Cooke; Jean Weissenbach

1986-01-01

204

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. PMID:24260373

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

2013-01-01

205

Double-strand break repair on sex chromosomes: challenges during male meiotic prophase.  

PubMed

During meiotic prophase, DNA double-strand break (DSB) repair-mediated homologous recombination (HR) occurs for exchange of genetic information between homologous chromosomes. Unlike autosomes or female sex chromosomes, human male sex chromosomes X and Y share little homology. Although DSBs are generated throughout male sex chromosomes, homologous recombination does not occur for most regions and DSB repair process is significantly prolonged. As a result, male sex chromosomes are coated with many DNA damage response proteins and form a unique chromatin structure known as the XY body. Interestingly, associated with the prolonged DSB repair, transcription is repressed in the XY body but not in autosomes, a phenomenon known as meiotic sex chromosome inactivation (MSCI), which is critical for male meiosis. Here using mice as model organisms, we briefly summarize recent progress on DSB repair in meiotic prophase and focus on the mechanism and function of DNA damage response in the XY body. PMID:25565522

Lu, Lin-Yu; Yu, Xiaochun

2015-02-16

206

The use of repetitive DNA in cytogenetic studies of plant sex chromosomes.  

PubMed

The structure of sex chromosomes in plants was analyzed by fluorescent in situ hybridization (FISH) with repetitive DNAs. FISH probes were successfully obtained from DNA libraries that were amplified from microdissected sex chromosomes. Some probes hybridized to the subtelomeric regions, where many kinds of repetitive DNAs are located with intrachromosomal similarity of their repeat units rather than interchromosomal similarity. For example, FISH with the subtelomeric repetitive sequence can easily show the location of the pseudoautosomal region (PAR) on the X chromosome of Silene latifolia. The other probes were localized on the interstitial region of the sex chromosomes. The interstitial region contains chloroplast DNAs or neighboring sequences of the internal telomeres, suggesting insertion or translocation occurred during differentiation of the sex chromosome. These data are very informative for understanding the structure of the plant sex chromosomes and their evolutionary process. PMID:18504354

Kazama, Y; Matsunaga, S

2008-01-01

207

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

PubMed

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

Benavente, R; Wettstein, R

1980-01-01

208

Sex chromosomes and karyotype of the (nearly) mythical creature, the Gila monster, Heloderma suspectum (Squamata: Helodermatidae).  

PubMed

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

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

2014-01-01

209

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

PubMed Central

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

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

2014-01-01

210

Genome-wide gene expression effects of sex chromosome imprinting in Drosophila.  

PubMed

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. PMID:24318925

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

2014-01-01

211

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

212

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. PMID:21408187

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

2011-01-01

213

[Case of azoospermia patient with a chromosomal abnormality considered a ring Y chromosome].  

PubMed

A 43-year-old man came to our clinic complaining of infertility and semen analysis showed azoospermia. Analysis of chromosomes showed a mosaic 45, XO/46, X, ?mar1/46, X, ?mar2 karyotype, and the marker chromosomes were considered to be two kinds of ring Y chromosomes. Y chromosome microdeletion analysis showed partial deletion of Azoospermic Factor (AZF) a, and complete deletion of AZFb and AZFc. The patient gave up having a child because these results indicated that no sperm would be collected even if Testicular Sperm Extraction (TESE) were performed. PMID:25511948

Kuroda, Shinnosuke; Yumura, Yasushi; Hamanoue, Haruka; Yasuda, Kengo; Yamanaka, Hiroyuki; Sanjo, Hiroyuki; Takeshima, Teppei; Kobayashi, Masataka; Kato, Yoshitake; Iwasaki, Akira; Noguchi, Kazumi

2014-11-01

214

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

215

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

PubMed Central

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

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

1989-01-01

216

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

217

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

218

Male only progeny in Anastrepha suspensa by RNAi-induced sex reversion of chromosomal females  

Microsoft Academic Search

In Tephritidae sex determination is established by orthologs to the Drosophila melanogaster transformer and transformer-2 genes, though the primary signals for sex determination differ. The presence of the Y chromosome in the tephritid species is critical for male differentiation, while the ratio of X chromosomes to autosome ploidy is critical in drosophilids. Here the isolation, expression and function of tra

Marc F. Schetelig; Andreina Milano; Giuseppe Saccone; Alfred M. Handler

219

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

220

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

221

Syndromes and constitutional chromosomal abnormalities associated with Wilms tumour  

PubMed Central

Wilms tumour has been reported in association with over 50 different clinical conditions and several abnormal constitutional karyotypes. Conclusive evidence of an increased risk of Wilms tumour exists for only a minority of these conditions, including WT1 associated syndromes, familial Wilms tumour, and certain overgrowth conditions such as Beckwith?Wiedemann syndrome. In many reported conditions the rare co?occurrence of Wilms tumour is probably due to chance. However, for several conditions the available evidence cannot either confirm or exclude an increased risk, usually because of the rarity of the syndrome. In addition, emerging evidence suggests that an increased risk of Wilms tumour occurs only in a subset of individuals for some syndromes. The complex clinical and molecular heterogeneity of disorders associated with Wilms tumour, together with the apparent absence of functional links between most of the known predisposition genes, suggests that abrogation of a variety of pathways can promote Wilms tumorigenesis. PMID:16690728

Scott, R H; Stiller, C A; Walker, L; Rahman, N

2006-01-01

222

vol. 160, supplement the american naturalist december 2002 Sex Chromosomes and Sexual Selection in Poeciliid Fishes  

E-print Network

vol. 160, supplement the american naturalist december 2002 Sex Chromosomes and Sexual Selection can be strongly influenced by linkage of attractive male traits to the Y chromosome and female preferences to the X chromosome in male heterogametic species. Such linkage patterns are predicted by models

223

Abnormal chromosome behavior during meiosis in the allotetraploid of Carassius auratus red var. (?)?×?Megalobrama amblycephala (?)  

PubMed Central

Background Allopolyploids generally undergo bivalent pairing at meiosis because only homologous chromosomes pair up. On the other hand, several studies have documented abnormal chromosome behavior during mitosis and meiosis in allopolyploids plants leading to the production of gametes with complete paternal or maternal chromosomes. Polyploidy is relatively rare in animals compared with plants; thus, chromosome behavior at meiosis in the allopolyploid animals is poorly understood. Results Tetraploid hybrids (abbreviated as 4nRB) (4n?=?148, RRBB) of Carassius auratus red var. (abbreviated as RCC) (2n?=?100, RR) (?)?×?Megalobrama amblycephala (abbreviated as BSB) (2n?=?48, BB) (?) generated gametes of different size. To test the genetic composition of these gametes, the gynogenetic offspring and backcross progenies of 4nRB were produced, and their genetic composition were examined by chromosome analysis and FISH. Our results suggest that 4nRB can produce several types of gametes with different genetic compositions, including allotetraploid (RRBB), autotriploid (RRR), autodiploid (RR), and haploid (R) gametes. Conclusions This study provides direct evidence of abnormal chromosome behavior during meiosis in an allotetraploid fish. PMID:25178799

2014-01-01

224

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

PubMed

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

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

2015-05-01

225

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. PMID:25031576

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

2014-01-01

226

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. PMID:22792396

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

2012-01-01

227

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

PubMed

The rise of sexual dimorphism is thought to coincide with the evolution of sex chromosomes. Yet because sex chromosomes in many species are ancient, we lack empirical evidence of the earliest stages of this transition. We use QTL analysis to examine the genetic architecture of sexual dimorphism in subdioecious octoploid Fragaria virginiana. We demonstrate that the region housing the male-function locus controls the majority of quantitative variation in proportion fruit set, confirming the existence of a proto-sex chromosome, and houses major QTL for eight additional sexually dimorphic traits, consistent with theory and data from animals and plants with more advanced sex chromosomes. We also detected autosomal QTL, demonstrating contributions to phenotypic variation in sexually dimorphic traits outside the sex-determining region. Moreover, for proportion seed set we found significant epistatic interactions between autosomal QTL and the male-function locus, indicating sex-limited QTL. We identified linked QTL reflecting trade-offs between male and female traits expected from theory and positive integration of male traits. These findings indicate the potential for the evolution of greater sexual dimorphism. Involvement of linkage groups homeologous to the proto-sex chromosome in these correlations reflects the polyploid origin of F. virginiana and raises the possibility that chromosomes in this homeologous group were predisposed to become the sex chromosome. PMID:21062281

Spigler, Rachel B; Lewers, Kim S; Ashman, Tia-Lynn

2011-04-01

228

Hybrid speciation in sparrows II: a role for sex chromosomes?  

PubMed

Homoploid hybrid speciation in animals is poorly understood, mainly because of the scarcity of well-documented cases. Here, we present the results of a multilocus sequence analysis on the house sparrow (Passer domesticus), Spanish sparrow (P. hispaniolensis) and their proposed hybrid descendant, the Italian sparrow (P. italiae). The Italian sparrow is shown to be genetically intermediate between the house sparrow and Spanish sparrow, exhibiting genealogical discordance and a mosaic pattern of alleles derived from either of the putative parental species. The average variation on the Z chromosome was significantly reduced compared with autosomal variation in the putative parental species, the house sparrow and Spanish sparrow. Additionally, divergence between the two species was elevated on the Z chromosome relative to the autosomes. This pattern of variation and divergence is consistent with reduced introgression of Z-linked genes and/or a faster-Z effect (increased rate of adaptive divergence on the Z). F(ST) -outlier tests were consistent with the faster-Z hypothesis: two of five Z-linked loci (CHD1Z and PLAA) were identified as candidates for being subject to positive, divergent selection in the putative parental species. Interestingly, the two latter genes showed a mosaic pattern in the (hybrid) Italian sparrow; that is, the Italian sparrow was found to be fixed for Spanish sparrow alleles at CHD1Z and to mainly have house sparrow alleles at PLAA. Preliminary evidence presented in this study thus suggests that sex chromosomes may play a significant role in this case of homoploid hybrid speciation. PMID:21762432

Elgvin, Tore O; Hermansen, Jo S; Fijarczyk, Anna; Bonnet, Timothée; Borge, Thomas; Saether, Stein A; Voje, Kjetil L; Saetre, Glenn-Peter

2011-09-01

229

Male-biased distribution of the human Y chromosomal genes SRY and ZFY in the lizard Calotes versicolor , which lacks sex chromosomes and temperature-dependent sex determination  

Microsoft Academic Search

In the present investigation on the lizard Calotes versicolor, which lacks temperature-dependent sex determination, all the conventional cytological techniques used failed to resolve a distinguishable pair of sex chromosomes. However, probing of the genome with the human Y-linked genes SRY and ZFY showed sex-specific bias in their distribution. While the SRY probe hybridized to all the males, more than half

Subramaniam Ganesh; Jayashree Mohanty; Rajiva Raman

1997-01-01

230

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

Microsoft Academic Search

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

Sergio V Flores; Amy L Evans; Bryant F McAllister

2008-01-01

231

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

232

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

E-print Network

on the sex chromosomes play a direct role in sexual differentiation of brain and behavior. We used mice to induce masculine patterns of neural differentiation that lead to sex differences in brain and behavior) before differentiation of the gonads. X- and Y-linked genes con- tribute to this sex difference (Burgoyne

de Vries, Geert J.

233

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

234

From chromosomal abnormalities to the identification of target genes in mouse models of breast cancer.  

PubMed

Cytogenetic studies of breast cancer cells have identified numerous chromosomal imbalances, including gains in human chromosome regions 1q, 4p, 8q, and 20q and losses in regions 1p, 3p, 6q, 11q, 16q, 17p, and 22q. Mouse models have been developed to study the mechanisms of mammary carcinogenesis, and in most cases, the corresponding karyotypes have been reported. Here, I summarize the cytogenetic findings and the candidate genes that are involved in mammary tumorigenesis. The most commonly altered chromosomes in mouse breast cancer models are chromosomes 4 and 11, which are orthologous to human chromosomes that are also affected by chromosomal abnormalities in human breast cancer. The genes that are affected by chromosomal imbalances in mouse models have also been found to participate in human breast cancer. In addition, the amplification and overexpression of several new genes in mouse models have subsequently been confirmed in human breast cancer. In this review, I compile information on the available karyotypes for mouse breast cancer models. PMID:25176624

Fabris, Victoria T

2014-06-01

235

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 PMID:12107843

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

2002-01-01

236

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

PubMed

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, subdioecious wild strawberry, Fragaria virginiana Mill., based on a whole-genome simple sequence repeat (SSR)-based genetic map and on mapping sex determination as two qualitative traits, male and female function. The resultant total map length is 2373 cM and includes 212 markers on 42 linkage groups (mean marker spacing: 14 cM). We estimated that approximately 70 and 90% of the total F. virginiana genetic map resides within 10 and 20 cM of a marker on this map, respectively. Both sex expression traits mapped to the same linkage group, separated by approximately 6 cM, along with two SSR markers. Together, our phenotypic and genetic mapping results support a model of gender determination in subdioecious F. virginiana with at least two linked loci (or gene regions) with major effects. Reconstruction of parental genotypes at these loci reveals that both female and hermaphrodite heterogamety exist in this species. Evidence of recombination between the sex-determining loci, an important hallmark of incipient sex chromosomes, suggest that F. virginiana is an example of the youngest sex chromosome in plants and thus a novel model system for the study of sex chromosome evolution. PMID:18797475

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

2008-12-01

237

A Unique Sex Chromosome System in the Knifefish Gymnotus bahianus with Inferences About Chromosomal Evolution of Gymnotidae.  

PubMed

Cytogenetic studies in Neotropical electric knifefish of genus Gymnotus have shown a remarkable interspecific variability, including distinct sex chromosome systems. In this study, we present the first chromosomal data in Gymnotus bahianus from Contas River basin, northeastern South America. Based on extensive analyses, the modal diploid values were 2n = 36 (30m/sm + 6st) for females and 2n = 37 (32m/sm + 5st) for males. Therefore, a novel XX/XY1Y2 sex chromosome system is described for the genus. Single nucleolar organizer regions (NORs) interspersed to GC-rich sites were detected on a subtelocentric pair (7th) for both sexes and confirmed by ?uorescent in situ hybridization with 18S rDNA probes. Heterochromatin was detected at pericentromeric regions of all chromosomes and interspersed to NORs on pair 7 and 5S rDNA cistrons on pair 9. The highly differentiated karyotype of Gymnoytus bahianus, with low diploid numbers and a unique XX/XY1Y2 system, reinforces the independent origin of sex chromosomes in Gymnotiformes and seems to reflect the particular evolutionary history of this species in a small and isolated drainage system. Moreover, in spite of morphological similarities, the present results indicate a remarkable chromosomal divergence in relation to closely related species such as G. sylvius and G. carapo. PMID:25596613

Almeida, Josivanda S; Migues, Vitor H; Diniz, Débora; Affonso, Paulo Roberto A M

2015-01-01

238

Prognostic Importance of Structural Chromosomal Abnormalities in Children With Hyperdiploid (>50 Chromosomes) Acute Lymphoblastic Leukemia  

Microsoft Academic Search

Approximately one fourth of children with newly diagnosed acute lymphoblastic leukemia (ALL) have hyperdiploid (>50 chromosomes) blasts and a relatively favorable prognosis. Nonetheless, a substantial proportion of these patients fail therapy. We studied 1 38 children (70 male. 68 female) with hyperdiploid >50 ALL to assess initial clinical and cytoge- netic features that might predict treatment failure. In 85 of

Ching-Hon Pui; Susana C. Raimondi; Richard K. Dodge; Gaston K. Rivera; H. Fuchs; Minnie Abromowitch; A. Thomas Look; Wayne L. Furman; William M. Crist; Dorothy L. Williams

1989-01-01

239

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

PubMed

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

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

2014-01-01

240

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. PMID:24451624

Bollen, Sander; Mah, Nancy

2014-01-01

241

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

242

Karyotype evolution and sex chromosome differentiation in schistosomes (Trematoda, Schistosomatidae)  

Microsoft Academic Search

The morphology of C-banded metaphase chromosomes has been studied in two hermaphroditic and ten gonochoristic digenetic trematodes (schistosomes). Comparison of numbers and morphology of chromosomes indicates that the karyotype of primitive trematodes probably was composed of 10 (or 11) pairs of telocentric or subtelocentrie chromosomes, and reduction of chromosome numbers in advanced species resulted from centromeric fusion rather than elimination

Abraham I. Grossman; Robert B. Short; George D. Cain

1981-01-01

243

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. These studies were conducted by two consortia, one led by scientists at the National Cancer Institute, and one by Gene Environment Association Studies (GENEVA) which is sponsored by the National Human Genome Research Institute.

244

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

Microsoft Academic Search

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

Kypros H. Nicolaides

2004-01-01

245

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

PubMed

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

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

2009-01-01

246

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. PMID:23271937

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

2012-01-01

247

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

248

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 PMID:7918348

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

1994-01-01

249

Differentiation of Z and W Chromosomes Revealed by Replication Banding and FISH Mapping of Sex-chromosome-linked DNA Markers in the Cassowary (Aves, Ratitae)  

Microsoft Academic Search

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

Chizuko Nishida-Umehara; Atushi Fujiwara; Akira Ogawa; Shigeki Mizuno; Syuiti Abe; Michihiro C. Yoshida

1999-01-01

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

Comparative chromosome painting between two marsupials: origins of an XX\\/XY 1 Y 2 sex chromosome system  

Microsoft Academic Search

Cross-species chromosome painting was used to investigate genome rearrangements between tammar wallaby Macropus eugenii (2n = 16) and the swamp wallaby Wallabia bicolor (2n = 10?\\/11?), which diverged about 6 million years ago. The swamp wallaby has an XX female:XY1Y2 male sex chromosome system thought to have resulted from a fusion between an autosome and the small original X, not

Roland Toder; Rachel J. W. O’Neill; Johannes Wienberg; Patricia C. M. O’Brien; Lucille Voullaire; Jennifer A. Marshall-Graves

1997-01-01

252

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

253

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

Microsoft Academic Search

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

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

2009-01-01

254

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

PubMed

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

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

2008-06-01

255

The balanced lethal system of crested newts: a ghost of sex chromosomes past?  

PubMed

Balanced lethal systems are more than biological curiosities: as theory predicts, they should quickly be eliminated through the joint forces of recombination and selection. That such systems might become fixed in natural populations poses a challenge to evolutionary theory. Here we address the case of a balanced lethal system fixed in crested newts and related species, which makes 50% of offspring die early in development. All adults are heteromorphic for chromosome pair 1. The two homologues (1A and 1B) have different recessive deleterious alleles fixed on a nonrecombining segment, so that heterozygotes are viable, while homozygotes are lethal. Given such a strong segregation load, how could autosomes stop recombining? We propose a role for a sex-chromosome turnover from pair 1 (putative ancestral sex chromosome) to pair 4 (currently active sex chromosome). Accordingly, 1A and 1B represent two variants (Y(A) and Y(B)) of the Y chromosome from an ancestral male-heterogametic system. We formalize a scenario in which turnovers are driven by sex ratio selection stemming from gene-environment interactions on sex determination. Individual-based simulations show that a balanced lethal system can be fixed with significant likelihood, provided the masculinizing allele on chromosome 4 appears after the elimination of the feminizing allele on chromosome 1. Our study illustrates how strikingly maladaptive traits might evolve through natural selection. PMID:23149410

Grossen, Christine; Neuenschwander, Samuel; Perrin, Nicolas

2012-12-01

256

Small but mighty: the evolutionary dynamics of W and Y sex chromosomes  

PubMed Central

Although sex chromosomes have been the focus of a great deal of scientific scrutiny, most interest has centred on understanding the evolution and relative importance of X and Z chromosomes. By contrast, the sex-limited W and Y chromosomes have received far less attention, both because of their generally degenerate nature and the difficulty in studying non-recombining and often highly heterochromatic genomic regions. However, recent theory and empirical evidence suggest that the W and Y chromosomes play a far more important role in sex-specific fitness traits than would be expected based on their size alone, and this importance may explain the persistence of some Y and W chromosomes in the face of powerful degradative forces. In addition to their role in fertility and fecundity, the sex-limited nature of these genomic regions results in unique evolutionary forces acting on Y and W chromosomes, implicating them as potentially major contributors to sexual selection and speciation. Recent empirical studies have borne out these predictions and revealed that some W and Y chromosomes play a vital role in key sex-specific evolutionary processes. PMID:22038285

2012-01-01

257

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. PMID:20923978

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

2010-01-01

258

Comparative genetic mapping points to different sex chromosomes in sibling species of wild strawberry (Fragaria).  

PubMed

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. PMID:20923978

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

2010-12-01

259

Comprehensive analysis of Alu-associated diversity on the human sex chromosomes  

Microsoft Academic Search

A comprehensive analysis of the human sex chromosomes was undertaken to assess Alu-associated human genomic diversity and to identify novel Alu insertion polymorphisms for the study of human evolution. Three hundred forty-five recently integrated Alu elements from eight different Alu subfamilies were identified on the X and Y chromosomes, 225 of which were selected and analyzed by polymerase chain reaction

Pauline A. Callinan; Dale J. Hedges; Abdel-Halim Salem; Jinchuan Xing; Jerilyn A. Walker; Randall K. Garber; W. Scott Watkins; Michael J. Bamshad; Lynn B. Jorde; Mark A. Batzer

2003-01-01

260

Pseudoautosomal DNA sequences in the pairing region of the human sex chromosomes  

Microsoft Academic Search

A DNA probe from a human Y chromosome-derived cosmid detects a single-copy genomic DNA fragment which can appear in different allelic forms shared by both sex chromosomes. Variants at this DNA locus show an autosomal pattern of inheritance, undergo recombination with sexual phenotype and can therefore be described as `pseudoautosomal'. Another probe from the same cosmid detects a sequence repeated

Marie-Christine Simmler; François Rouyer; Gilles Vergnaud; Minna Nyström-Lahti; Kim Yen Ngo; Albert de La Chapelle; Jean Weissenbach

1985-01-01

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. PMID:24327996

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

2013-01-01

262

Masked complex chromosome rearrangement in a child thought to have del(8qter) as the sole cytogenetic abnormality  

Microsoft Academic Search

Cytogenetic analyses of constitutional diseases have disclosed several chromosomal rearrangements. At the molecular level, these rearrangements often result in the breakage of genes or alteration of genome architecture. Fluorescence in situ hybridization (FISH) and molecular investigations of a patient showing hypotonia and dysmorphic traits revealed a masked complex chromosome abnormality previously detected by G-banding as a simple 8qter deletion. To

C. Surace; M. C. Digilio; A. Lombardo; P. Sirleto; A. C. Tomaiuolo; M. C. Roberti; R. Capolino; A. Angioni

2008-01-01

263

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

PubMed Central

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

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

2013-01-01

264

Independent evolution of transcriptional inactivation on sex chromosomes in birds and mammals.  

PubMed

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

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

2013-01-01

265

Male only progeny in Anastrepha suspensa by RNAi-induced sex reversion of chromosomal females  

Technology Transfer Automated Retrieval System (TEKTRAN)

In Tephritidae sex determination is established by orthologs to the Drosophila melanogaster transformer and transformer-2 genes. In contrast, primary signals for sex determination are different in these species corresponding to the number of X chromosomes (XSE) in Drosophilidae species and to the pr...

266

Comparative genetic mapping in Fragaria virginiana reveals autosomal origin of sex chromosome  

Technology Transfer Automated Retrieval System (TEKTRAN)

Although most flowering plants are hermaphrodite, separate sexes (dioecy) have evolved repeatedly. The evolution of sex chromosomes from autosomes can often, but not always, accompany this transition. Thus, many have argued that plant genera that contain both hermaphroditic and dioecious members pro...

267

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

Microsoft Academic Search

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

Roberta Bergero; Alan Forrest; Esther Kamau; Deborah Charlesworth

2007-01-01

268

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

269

Chromosome assignment of two cloned DNA probes hybridizing predominantly to human sex chromosomes  

Microsoft Academic Search

In situ hybridization experiments were carried out with two clones, YACG 35 and 2.8, which had been selected from two genomic libraries strongly enriched for the human Y chromosome. Besides the human Y chromosome, both sequences strongly hybridized to the human X chromosome, with few minor binding sites on autosomes. In particular, on the X chromosome DNA from clone YACG

Gudrun A. Rappold; T. Cremer; C. Cremer; W. Back; J. Bogenberger; H. J. Cooke

1984-01-01

270

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. PMID:24465491

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

2014-01-01

271

Reduced representation genome sequencing suggests low diversity on the sex chromosomes of tonkean macaque monkeys.  

PubMed

In species with separate sexes, social systems can differ in the relative variances of male versus female reproductive success. Papionin monkeys (macaques, mangabeys, mandrills, drills, baboons, and geladas) exhibit hallmarks of a high variance in male reproductive success, including a female-biased adult sex ratio and prominent sexual dimorphism. To explore the potential genomic consequences of such sex differences, we used a reduced representation genome sequencing approach to quantifying polymorphism at sites on autosomes and sex chromosomes of the tonkean macaque (Macaca tonkeana), a species endemic to the Indonesian island of Sulawesi. The ratio of nucleotide diversity of the X chromosome to that of the autosomes was less than the value (0.75) expected with a 1:1 sex ratio and no sex differences in the variance in reproductive success. However, the significance of this difference was dependent on which outgroup was used to standardize diversity levels. Using a new model that includes the effects of varying population size, sex differences in mutation rate between the autosomes and X chromosome, and GC-biased gene conversion (gBGC) or selection on GC content, we found that the maximum-likelihood estimate of the ratio of effective population size of the X chromosome to that of the autosomes was 0.68, which did not differ significantly from 0.75. We also found evidence for 1) a higher level of purifying selection on genic than nongenic regions, 2) gBGC or natural selection favoring increased GC content, 3) a dynamic demography characterized by population growth and contraction, 4) a higher mutation rate in males than females, and 5) a very low polymorphism level on the Y chromosome. These findings shed light on the population genomic consequences of sex differences in the variance in reproductive success, which appear to be modest in the tonkean macaque; they also suggest the occurrence of hitchhiking on the Y chromosome. PMID:24987106

Evans, Ben J; Zeng, Kai; Esselstyn, Jacob A; Charlesworth, Brian; Melnick, Don J

2014-09-01

272

Repetitive DNA chromosomal organization in the cricket Cycloptiloides americanus: a case of the unusual X1X 20 sex chromosome system in Orthoptera.  

PubMed

A common placement for most sex chromosomes that is involved in their evolutionary histories is the accumulation of distinct classes of repetitive DNAs. Here, with the aim of understanding the poorly studied repetitive DNA organization in crickets and its possible role in sex chromosome differentiation, we characterized the chromosomes of the cricket species Cycloptiloides americanus, a species with the remarkable presence of the unusual sex chromosome system X1X20?/X1X1X2X2?. For these proposes, we used C-banding and mapping through the fluorescence in situ hybridization of some repetitive DNAs. The C-banding and distribution of highly and moderately repetitive DNAs (C 0t-1 DNA) varied depending of the chromosome. The greater accumulation of repetitive DNAs in the X2 chromosome was evidenced. The microsatellites were spread along entire chromosomes, but (AG)10 and (TAA)10 were less enriched, mainly in the centromeric areas. Among the multigene families, the 18S rDNA was spread throughout almost all of the chromosomes, except for pair 5 and X2, while the U2 snDNA was placed exclusively in the largest chromosome. Finally, the 5S rDNA was exclusively located in the short arms of the sex chromosomes. The obtained data reinforce the importance of chromosomal dissociation and inversion as a primary evolutionary mechanism to generate neo-sex chromosomes in the species studied, followed by the repetitive DNAs accumulation. Moreover the exclusive placement of 5S rDNA in the sex chromosomes suggests the involvement of this sequence in sex chromosome recognition throughout meiosis and, consequently, their maintenance, in addition to their avoiding degeneration. PMID:25373534

Palacios-Gimenez, Octavio M; Cabral-de-Mello, Diogo C

2015-04-01

273

Neural Activation During Mental Rotation in Complete Androgen Insensitivity Syndrome: the Influence of Sex Hormones and Sex Chromosomes.  

PubMed

Sex hormones, androgens in particular, are hypothesized to play a key role in the sexual differentiation of the human brain. However, possible direct effects of the sex chromosomes, that is, XX or XY, have not been well studied in humans. Individuals with complete androgen insensitivity syndrome (CAIS), who have a 46,XY karyotype but a female phenotype due to a complete androgen resistance, enable us to study the separate effects of gonadal hormones versus sex chromosomes on neural sex differences. Therefore, in the present study, we compared 46,XY men (n = 30) and 46,XX women (n = 29) to 46,XY individuals with CAIS (n = 21) on a mental rotation task using functional magnetic resonance imaging. Previously reported sex differences in neural activation during mental rotation were replicated in the control groups, with control men showing more activation in the inferior parietal lobe than control women. Individuals with CAIS showed a female-like neural activation pattern in the parietal lobe, indicating feminization of the brain in CAIS. Furthermore, this first neuroimaging study in individuals with CAIS provides evidence that sex differences in regional brain function during mental rotation are most likely not directly driven by genetic sex, but rather reflect gonadal hormone exposure. PMID:25452569

van Hemmen, Judy; Veltman, Dick J; Hoekzema, Elseline; Cohen-Kettenis, Peggy T; Dessens, Arianne B; Bakker, Julie

2014-12-01

274

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

PubMed Central

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, the Mongolian gerbil (Meriones unguiculatus). We have analyzed the location of synaptonemal complex (SC) proteins SYCP1 and SYCP3, as well as three proteins involved in the process of meiotic recombination (RAD51, MLH1, and ?-H2AX). Our results show that although X and Y chromosomes are associated at pachytene and form a sex body, their axial elements (AEs) do not contact, and they never assemble a SC central element. Furthermore, MLH1 is not detected on the AEs of the sex chromosomes, indicating the absence of reciprocal recombination. At diplotene the organization of sex chromosomes changes strikingly, their AEs associate end to end, and SYCP3 forms an intricate network that occupies the Y chromosome and the distal region of the X chromosome long arm. Both the association of sex chromosomes and the SYCP3 structure are maintained until metaphase I. In anaphase I sex chromosomes migrate to opposite poles, but SYCP3 filaments connecting both chromosomes are observed. Hence, one can assume that SYCP3 modifications detected from diplotene onwards are correlated with the maintenance of sex chromosome association. These results demonstrate that some components of the SC may participate in the segregation of achiasmate sex chromosomes in eutherian mammals. PMID:17983272

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

2007-01-01

275

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

Microsoft Academic Search

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

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

2002-01-01

276

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

SciTech Connect

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

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

1995-12-01

277

An XX\\/XY Sex Chromosome System in a Fish Species, Hoplias malabaricus , with a Polymorphic NOR-Bearing X Chromosome  

Microsoft Academic Search

Cytogenetic studies were carried out in the fish, Hoplias malabaricus, from the Parque Florestal do Rio Doce (Brazil). This population is characterized by 2n = 42 chromosomes for both males and females and an XX\\/XY sex chromosome system, confirmed through several banding methods. Females show 24 metacentric, 16 submetacentric and 2 subtelocentric chromosomes. Males show 24 metacentric, 17 submetacentric and

Guassenir Gonçalves Born; Luiz Antonio Carlos Bertollo

2000-01-01

278

Detection of sex chromosome aneuploidy in dog spermatozoa by triple color fluorescence in situ hybridization.  

PubMed

With the development of a direct visualization of sex chromosome in a single sperm by fluorescence in situ hybridization (FISH) technique, the frequency of aberration (aneuploidy) in spermatozoa in several mammals has been investigated. However, there is no report in the incidence of X-Y aneuploidy in the sperm population of dogs. Therefore, in this study, the aneuploidy in dog spermatozoa was examined by multicolor FISH using specific molecular probes for canine sex chromosomes and autosome. Semen from eight male Labrador retrievers was used as specimen. For decondensation of sperm nuclei, the specimen was treated with 1 M NaOH for 4 minutes at room temperature. Probes for chromosomes X, Y, and 1, labeled with SpectrumGreen, Cy3 and Cy5, respectively, were hybridized with decondensed spermatozoa. Fluorescence in situ hybridization signals in sperm heads were clearly detected in each specimen, regardless of the sperm donor. The FISH signal of at least one of the three probes was detected in all sperm heads examined. There was no significant difference between the theoretical ratio (50:50) and the observed ratio of X and Y chromosomes in spermatozoa of all the eight dogs. Mean percentage of sex chromosome aneuploidy was 0.127% (ranged between 0% and 0.316%). This percentage of canine sex chromosome aneuploidy was lower than the one reported in cattle, horses, river buffalo, and goats sperm, but higher than that observed in mice and sheep. PMID:24962971

Komaki, Haruna; Oi, Maya; Suzuki, Hiroshi

2014-09-01

279

Microinjected DNA from the X chromosome affects sex determination in Caenorhabditis elegans.  

PubMed

The signal for sex determination in the nematode Caenorhabditis elegans is the ratio of the number of X chromosomes to the number of sets of autosomes (X/A ratio). By previous genetic tests, elements that feminized chromosomal males appeared to be widespread on the X chromosome, but the nature of these elements was not determined. In experiments to define a feminizing element molecularly, cloned sequences were added to chromosomally male embryos by microinjection into the mother. Three different X-chromosome clones, including part of an actin gene, part of a myosin heavy chain gene, and all of two myosin light chain genes, feminize chromosomal males. Both somatic and germline aspects of sex determination are affected. In contrast, about 40 kilobases of nematode autosomal DNA, phage lambda DNA, and plasmid pBR322 DNA do not affect sex determination. A feminizing region was localized to a maximum of 131 base pairs within an intron of the X-linked actin gene; a part of the gene that does not have this region is not feminizing. The results suggest that short, discrete elements found associated with many X-linked genes may act as signals for sex determination in C. elegans. PMID:2973125

McCoubrey, W K; Nordstrom, K D; Meneely, P M

1988-11-25

280

Identification of Sex Chromosomes by Means of Comparative Genomic Hybridization in a Lizard, Eremias multiocellata.  

PubMed

Eremias multiocellata is a viviparous lizard that is known to exhibit temperature-dependent sex determination (TSD). Conventional Giemsa staining under light microscope examination has identified the karyotype of this species to be 2 n = 36 I + 2 m, with no detectable heteromorphic sex chromosomes. However, a highly differentiated female-specific chromosome, W, which is homomorphic with the Z chromosome, is found in the present study by the high-resolution cytogenetic method of comparative genomic hybridization (CGH). The results show that E. multiocellata is a viviparous lizard with both TSD and ZW heterogametic sex chromosomes. Despite the fact that a different sex ratio of male offspring was found in two populations (separated by an altitude of 1400 m) in previous incubation experiments, we demonstrate, using genomic in situ hybridization (GISH), that there is no significant chromosomal loss or acquisition between the two populations. This suggests that temperature may play a more important role in lowland populations. These results most likely indicate that E. multiocellata is transitioning between the evolutionary processes of TSD and genotypic sex determination (GSD) systems, and also give clues to the effect of TSD versus GSD in this process. PMID:25826063

Wang, Cui; Tang, Xiaolong; Xin, Ying; Yue, Feng; Yan, Xuefeng; Liu, Bingbing; An, Bei; Wang, Xi; Chen, Qiang

2015-04-01

281

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. PMID:22377319

2012-01-01

282

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

PubMed

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

Dain, A

1977-01-01

283

Sperm DNA and sex chromosome differences between two geographical populations of the creeping vole, Microtus oregoni.  

PubMed

The relative DNA content of the "O" and Y chromosome-bearing sperm is presented for the creeping vole, Microtus oregoni. The animals had been trapped in Oregon and in Washington State. The two populations had very similar autosomal chromosome relationships but differed greatly in the size of their X chromosome (which is not carried by vole sperm) and in their Y chromosome. The greater size and banding differences of the Y chromosome of the Washington State vole compared to the Oregon vole paralleled the greater differences in sperm DNA between the Y-bearing sperm and the sperm carrying no sex chromosome (O). The actual DNA differences between O and Y sperm was 12.5% for the sperm from the Washington State voles and 9.1% for sperm from the Oregon voles. The difference in sperm DNA content (12.5%) for Washington State voles was far greater than the difference shown for other voles or other mammals. PMID:2248779

Johnson, L A; Clarke, R N

1990-10-01

284

Karyological characterization of the endemic Iberian rock lizard, Iberolacerta monticola (Squamata, Lacertidae): insights into sex chromosome evolution.  

PubMed

Rock lizards of the genus Iberolacerta constitute a promising model to examine the process of sex chromosome evolution, as these closely related taxa exhibit remarkable diversity in the degree of sex chromosome differentiation with no clear phylogenetic segregation, ranging from cryptic to highly heteromorphic ZW chromosomes and even multiple chromosome systems (Z1Z1Z2Z2/Z1Z2W). To gain a deeper insight into the patterns of karyotype and sex chromosome evolution, we performed a cytogenetic analysis based on conventional staining, banding techniques and fluorescence in situ hybridization in the species I. monticola, for which previous cytogenetic investigations did not detect differentiated sex chromosomes. The karyotype is composed of 2n = 36 acrocentric chromosomes. NORs and the major ribosomal genes were located in the subtelomeric region of chromosome pair 6. Hybridization signals of the telomeric sequences (TTAGGG)n were visualized at the telomeres of all chromosomes and interstitially in 5 chromosome pairs. C-banding showed constitutive heterochromatin at the centromeres of all chromosomes, as well as clear pericentromeric and light telomeric C-bands in several chromosome pairs. These results highlight some chromosomal markers which can be useful to identify species-specific diagnostic characters, although they may not accurately reflect the phylogenetic relationships among the taxa. In addition, C-banding revealed the presence of a heteromorphic ZW sex chromosome pair, where W is smaller than Z and almost completely heterochromatic. This finding sheds light on sex chromosome evolution in the genus Iberolacerta and suggests that further comparative cytogenetic analyses are needed to understand the processes underlying the origin, differentiation and plasticity of sex chromosome systems in lacertid lizards. PMID:24296524

Rojo, V; Giovannotti, M; Naveira, H; Nisi Cerioni, P; González-Tizón, A M; Caputo Barucchi, V; Galán, P; Olmo, E; Martínez-Lage, A

2014-01-01

285

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. PMID:12807790

Hiatt, Evelyn N; Dawe, R Kelly

2003-01-01

286

Array-Based Comparative Genomic Hybridization for the Genomewide Detection of Submicroscopic Chromosomal Abnormalities  

PubMed Central

Microdeletions and microduplications, not visible by routine chromosome analysis, are a major cause of human malformation and mental retardation. Novel high-resolution, whole-genome technologies can improve the diagnostic detection rate of these small chromosomal abnormalities. Array-based comparative genomic hybridization allows such a high-resolution screening by hybridizing differentially labeled test and reference DNAs to arrays consisting of thousands of genomic clones. In this study, we tested the diagnostic capacity of this technology using ?3,500 flourescent in situ hybridization–verified clones selected to cover the genome with an average of 1 clone per megabase (Mb). The sensitivity and specificity of the technology were tested in normal-versus-normal control experiments and through the screening of patients with known microdeletion syndromes. Subsequently, a series of 20 cytogenetically normal patients with mental retardation and dysmorphisms suggestive of a chromosomal abnormality were analyzed. In this series, three microdeletions and two microduplications were identified and validated. Two of these genomic changes were identified also in one of the parents, indicating that these are large-scale genomic polymorphisms. Deletions and duplications as small as 1 Mb could be reliably detected by our approach. The percentage of false-positive results was reduced to a minimum by use of a dye-swap-replicate analysis, all but eliminating the need for laborious validation experiments and facilitating implementation in a routine diagnostic setting. This high-resolution assay will facilitate the identification of novel genes involved in human mental retardation and/or malformation syndromes and will provide insight into the flexibility and plasticity of the human genome. PMID:14628292

Vissers, Lisenka E. L. M. ; de Vries, Bert B. A. ; Osoegawa, Kazutoyo ; Janssen, Irene M. ; Feuth, Ton ; Choy, Chik On ; Straatman, Huub ; van der Vliet, Walter ; Huys, Erik H. L. P. G. ; van Rijk, Anke ; Smeets, Dominique ; van Ravenswaaij-Arts, Conny M. A. ; Knoers, Nine V. ; van der Burgt, Ineke ; de Jong, Pieter J. ; Brunner, Han G. ; van Kessel, Ad Geurts ; Schoenmakers, Eric F. P. M. ; Veltman, Joris A. 

2003-01-01

287

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

SciTech Connect

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 a frequency of 1.34% in men age 76-80 years. In females, the baseline level for X chromosome loss is much higher than that seen for the Y chromosome in males. Even prepubertal females show a rate of X chromosome loss on the order of 1.5%-2.5%, rising to {approximately}4.5%-5% in women older than 75 years. Dividing the female probands into three biological age groups on the basis of sex hormone function (<13 years, 13-51 years, and >51 years), a significant correlation of X chromosome loss versus age could clearly be demonstrated in women beyond age 51 years. Females age 51-91 years showed monosomy X at a rate from 3.2% to 5.1%. In contrast to sex chromosomal loss, the frequency of autosomal monosomies does not change during the course of aging: chromosome 1 and chromosome 17 monosomic cells were found with a constant incidence of 1.2% and 1%, respectively. These data also indicate that autosome loss in interphase nuclei is not a function of chromosome size. 34 refs., 5 figs., 6 tabs.

Guttenbach, M.; Koschorz, B.; Bernthaler, U. [and others

1995-11-01

288

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

289

Regulation of the DNA damage response on male meiotic sex chromosomes.  

PubMed

During meiotic prophase in males, the sex chromosomes partially synapse to form the XY body, a unique structure that recruits proteins involved in the DNA damage response, which is believed to be important for silencing of the sex chromosomes. It remains elusive how the DNA damage response in the XY body is regulated. Here we show that H2AX-MDC1-RNF8 signaling, which is well characterized in somatic cells, is dispensable for the recruitment of proteins to the unsynapsed axes in the XY body. On the other hand, the DNA damage response that spreads over the sex chromosomes is largely similar to that in somatic cells. This analysis shows that there are important differences between the regulation of the DNA damage response at the XY body and at DNA damage sites in somatic cells. PMID:23812044

Lu, Lin-Yu; Xiong, Yi; Kuang, Henry; Korakavi, Gautam; Yu, Xiaochun

2013-01-01

290

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

PubMed Central

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

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

2014-01-01

291

Brain abnormalities, defective meiotic chromosome synapsis and female subfertility in HSF2 null mice  

PubMed Central

Heat shock factor 2, one of the four vertebrate HSFs, transcriptional regulators of heat shock gene expression, is active during embryogenesis and spermatogenesis, with unknown functions and targets. By disrupting the Hsf2 gene, we show that, although the lack of HSF2 is not embryonic lethal, Hsf2–/– mice suffer from brain abnormalities, and meiotic and gameto genesis defects in both genders. The disturbances in brain are characterized by the enlargement of lateral and third ventricles and the reduction of hippocampus and striatum, in correlation with HSF2 expression in proliferative cells of the neuroepithelium and in some ependymal cells in adults. Many developing spermatocytes are eliminated via apoptosis in a stage-specific manner in Hsf2–/– males, and pachytene spermatocytes also display structural defects in the synaptonemal complexes between homologous chromosomes. Hsf2–/– females suffer from multiple fertility defects: the production of abnormal eggs, the reduction in ovarian follicle number and the presence of hemorrhagic cystic follicles are consistent with meiotic defects. Hsf2–/– females also display hormone response defects, that can be rescued by superovulation treatment, and exhibit abnormal rates of luteinizing hormone receptor mRNAs. PMID:12032072

Kallio, Marko; Chang, Yunhua; Manuel, Martine; Alastalo, Tero-Pekka; Rallu, Murielle; Gitton, Yorick; Pirkkala, Lila; Loones, Marie-Thérèse; Paslaru, Liliana; Larney, Severine; Hiard, Sophie; Morange, Michel; Sistonen, Lea; Mezger, Valérie

2002-01-01

292

An early stage of ZW\\/ZZ sex chromosome differentiation in Poecilia sphenops var. melanistica (Poeciliidae, Cyprinodontiformes)  

Microsoft Academic Search

The mitotic and meiotic chromosomes of the American cyprinodont fish Poecilia sphenops var. melanistica were analysed. All 46 chromosomes are telocentric. By specific staining of the constitutive heterochromatin with C-banding and various AT-specific fluorochromes, the homomorphic chromosome pair 1 could be identified as sex chromosomes of the ZW\\/ZZ type. All female animals exhibit a W chromosome with a large region

T. Haaf; M. Schmid

1984-01-01

293

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

294

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

PubMed Central

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

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

2014-01-01

295

Sex reversal syndrome in the horse: four new cases of feminization in individuals carrying a 64,XY SRY negative chromosomal complement.  

PubMed

Horses are characterized as having a greater rate of chromosomal abnormalities than other species, which are mainly related to the sex chromosome pair and produce a series of different anomalies known as disorders in sexual development (DSD). In the present study, three Pura Raza Española (PRE) and one Menorquín (MEN) horses were studied and an incompatibility in their genetic and phenotypic sex were detected. Animals were karyotyped by conventional and molecular cytogenetic analyses and characterized using genomic techniques. Although all individuals, were totally unrelated, these animals had the same abnormality (64,XY SRY negative DSD) despite having an anatomically normal external mare phenotype. Therefore, this syndrome could remain undiagnosed in a large percentage of cases because the physiological and morphological symptoms are rare. In the present study, a slight gonadal dysgenesis was observed only in older individuals. Interestingly this chromosomal abnormality has been previously reported less than twenty times, and never in the PRE or MEN horses. With the present research, it is demonstrated that the use of genetic and cytogenetic diagnostic tools in veterinary practice could be an important complementary test to determine the origin of unexplained reproductive failures among horses. PMID:25308063

Anaya, Gabriel; Moreno-Millán, Miguel; Bugno-Poniewierska, Monika; Pawlina, Klaudia; Membrillo, Alberto; Molina, Antonio; Demyda-Peyrás, Sebastián

2014-12-10

296

High frequency of sex chromosomal disomy in spermatozoa of Lebanese infertile men.  

PubMed

In Lebanon, assisted reproductive techniques (ART) are widely used to overcome infertility, but the genetic risk associated with these techniques is still ignored. In this study, in order to estimate the transmission risk of paternal chromosomal anomalies to ART offspring, the meiotic segregation of chromosomes X, Y, 18, and 21 was analyzed by fluorescent in situ hybridization on the spermatozoa of 19 Lebanese infertile men. Our results show significantly higher frequencies of sex chromosome disomies in the group of patients with oligozoospermia compared with a control group of fertile males. Interestingly, the sex chromosome aneuploidy rates were highly variable between oligozoospermic patients, and ranged between 0.9% and 12.87%. No significant increase in aneuploidy rates was found for the group of nonoligozoospermic patients with asthenozoospermia and/or teratozoospermia. In addition, the disomy rate for chromosome 21 was analyzed in 8 patients, in whom higher disomy rates were shown as compared with the controls. Altogether, the results suggest that Lebanese oligozoospermic men undergoing ART may have an increased risk of transmitting sex chromosome anomalies to their offspring, as well as, in some cases, trisomy 21. Based on this work, genetic counseling programs for Lebanese infertile couples undergoing ART procedures should be developed, in order to improve the investigation and selection of Lebanese infertile couple candidates for ART procedures and optimize the choice of ART techniques. PMID:21164147

Younes, Berthes G; Hazzouri, Khaled M; Chaaban, Mustapha J; Karam, Walid G; Abou Jaoude, Imad F; Attieh, Joanna H; Hazzouri, Mira M

2011-01-01

297

Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids  

PubMed Central

The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F1 pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F1 sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F1 pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. PMID:21624978

He, J. H.; Shahid, M. Q.; Guo, H. B.; Cheng, X. A.; Liu, X. D.; Lu, Y. G.

2011-01-01

298

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. PMID:23211699

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

2013-01-01

299

Higher-order genome organization in platypus and chicken sperm and repositioning of sex chromosomes during mammalian evolution  

PubMed Central

In mammals, chromosomes occupy defined positions in sperm, whereas previous work in chicken showed random chromosome distribution. Monotremes (platypus and echidnas) are the most basal group of living mammals. They have elongated sperm like chicken and a complex sex chromosome system with homology to chicken sex chromosomes. We used platypus and chicken genomic clones to investigate genome organization in sperm. In chicken sperm, about half of the chromosomes investigated are organized non-randomly, whereas in platypus chromosome organization in sperm is almost entirely non-random. The use of genomic clones allowed us to determine chromosome orientation and chromatin compaction in sperm. We found that in both species chromosomes maintain orientation of chromosomes in sperm independent of random or non-random positioning along the sperm nucleus. The distance of loci correlated with the total length of sperm nuclei, suggesting that chromatin extension depends on sperm elongation. In platypus, most sex chromosomes cluster in the posterior region of the sperm nucleus, presumably the result of postmeiotic association of sex chromosomes. Chicken and platypus autosomes sharing homology with the human X chromosome located centrally in both species suggesting that this is the ancestral position. This suggests that in some therian mammals a more anterior position of the X chromosome has evolved independently. PMID:18726609

Tsend-Ayush, Enkhjargal; Dodge, Natasha; Mohr, Julia; Casey, Aaron; Himmelbauer, Heinz; Kremitzki, Colin L.; Schatzkamer, Kyriena; Graves, Tina; Warren, Wesley C.

2013-01-01

300

BrdU33258 Hoechst analysis of DNA replication in human lymphocytes with supernumerary or structurally abnormal X chromosomes  

Microsoft Academic Search

BrdU-33258 Hoechst techniques have been used to characterize DNA replication patterns in lymphocytes from human females with supernumerary or structurally abnormal X chromosomes. Fluorescence analysis permits identification of late replicating X chromosomes in a very high proportion of cells and affords a high resolution method for determining the interchange points of X-X and X-autosome translocations. Asynchrony among terminal replication patterns

Samuel A. Latt; Huntington F. Willard; Park S. Gerald

1976-01-01

301

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

302

Noninvasive Fetal Trisomy (NIFTY) test: an advanced noninvasive prenatal diagnosis methodology for fetal autosomal and sex chromosomal aneuploidies  

PubMed Central

Background Conventional prenatal screening tests, such as maternal serum tests and ultrasound scan, have limited resolution and accuracy. Methods We developed an advanced noninvasive prenatal diagnosis method based on massively parallel sequencing. The Noninvasive Fetal Trisomy (NIFTY) test, combines an optimized Student’s t-test with a locally weighted polynomial regression and binary hypotheses. We applied the NIFTY test to 903 pregnancies and compared the diagnostic results with those of full karyotyping. Results 16 of 16 trisomy 21, 12 of 12 trisomy 18, two of two trisomy 13, three of four 45, X, one of one XYY and two of two XXY abnormalities were correctly identified. But one false positive case of trisomy 18 and one false negative case of 45, X were observed. The test performed with 100% sensitivity and 99.9% specificity for autosomal aneuploidies and 85.7% sensitivity and 99.9% specificity for sex chromosomal aneuploidies. Compared with three previously reported z-score approaches with/without GC-bias removal and with internal control, the NIFTY test was more accurate and robust for the detection of both autosomal and sex chromosomal aneuploidies in fetuses. Conclusion Our study demonstrates a powerful and reliable methodology for noninvasive prenatal diagnosis. PMID:23198897

2012-01-01

303

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 PMID:7895709

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

1994-01-01

304

Autosomal location of genes from the conserved mammalian X in the platypus ( Ornithorhynchus anatinus ): implications for mammalian sex chromosome evolution  

Microsoft Academic Search

Mammalian sex chromosomes evolved from an ancient autosomal pair. Mapping of human X- and Y-borne genes in distantly related mammals and non-mammalian vertebrates has proved valuable to help deduce the evolution of this unique part of the genome. The platypus, a monotreme mammal distantly related to eutherians and marsupials, has an extraordinary sex chromosome system comprising five X and five

Paul D. Waters; Margaret L. Delbridge; Janine E. Deakin; Nisrine El-Mogharbel; Patrick J. Kirby; Denise R. Carvalho-Silva; Jennifer A. Marshall Graves

2005-01-01

305

The creeping vole, Microtus oregoni: karyotype and sex-chromosome differences between two geographical populations.  

PubMed

The G-banded karyotype of the creeping vole, Microtus oregoni, prepared from animals trapped in Oregon and Washington, is presented. The two populations had similar autosomal banding patterns but exhibited striking differences in their sex chromosomes. The X chromosome of voles captured in Oregon was 39% longer than that of voles trapped in Washington. The length difference was primarily due to an increase in size of light G-bands, which, in both populations, comprised large segments of the X chromosome. On C-banding, the X chromosome exhibited major blocks of constitutive heterochromatin corresponding to the light G-bands. In contrast, the Y chromosome of the Oregon voles was 24% shorter than that of the Washington voles and lacked the short arm and some terminal bands present in the Washington voles. PMID:3046846

Libbus, B L; Johnson, L A

1988-01-01

306

Sexually biased transcripts at early embryonic stages of the silkworm depend on the sex chromosome constitution.  

PubMed

In the silkworm, Bombyx mori, females are heterogametic (WZ) whereas males have two Z chromosomes. Femaleness of B. mori is determined by the presence of the W chromosome, suggesting that there is a dominant feminizing gene on this chromosome. Recently, by transcriptome analysis of B. mori embryos, we discovered that a single W-chromosome-derived PIWI-interacting RNA (piRNA) is the long-sought primary determinant of femaleness in B. mori. However, sexual bias in the transcriptome of B. mori early embryos has not yet been well characterized. Using deep sequencing data from molecularly sexed RNA of B. mori embryos, we identified and characterized 157 transcripts that are statistically differentially expressed between male and female early embryos. Most of the female-biased transcripts were transposons or repeat sequences that are produced presumably from the W chromosome. Bioinformatic analysis revealed that these repetitive sequences are piRNA precursors. In contrast, male-biased genes were frequently transcribed from the Z chromosome, suggesting that dosage compensation in Z-linked genes does not occur or is incomplete at early embryonic stages. Our analysis has drawn a picture of a global landscape of sexually biased transcriptome during early B. mori embyogenesis and has suggested for the first time that most sexually biased embryonic transcripts depend on sex chromosomes. PMID:25615878

Kawamoto, Munetaka; Koga, Hikaru; Kiuchi, Takashi; Shoji, Keisuke; Sugano, Sumio; Shimada, Toru; Suzuki, Yutaka; Katsuma, Susumu

2015-04-10

307

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

308

Characteristics of hematologic malignancies with coexisting t(9;22) and inv(16) chromosomal abnormalities  

PubMed Central

Background The coexistence of t(9;22)(q34;q11.2) and inv(16)(p13q22) chromosomal abnormalities is extremely uncommon, and only a small number of such cases have been reported. Here, we characterized 7 cases of hematologic malignancy exhibiting t(9;22) and inv(16) coexistence. Methods We reviewed the cytogenetic data for hematologic malignancies treated at the Catholic Blood and Marrow Transplantation Center between January 2004 and June 2013. We identified 7 cases exhibiting t(9;22) and inv(16) coexistence. In addition, we analyzed mutations in the IKZF1, NPM1, FLT3, N-RAS, K-RAS, c-KIT, and TP53 genes. Results Four cases of chronic myelogenous leukemia (CML; 1 chronic phase, 2 accelerated phase, and 1 blast phase) and 3 cases of acute myeloid leukemia (AML; 1 de novo and 2 therapy-related) were identified. The percentages of circulating blasts and bone marrow eosinophils were higher in AML cases than in CML cases (53% vs. 5% and 30% vs. 5.5%, respectively). The proportions of each chromosomal abnormality were used along with follow-up karyotyping results to identify secondary changes. In BCR/ABL, a p210 fusion transcript was associated with CML, whereas a p190 fusion transcript was associated with AML. One patient with AML harbored 2 mutations: c-KIT D816V and TP53 E11Q. All patients except 1 with CML blast phase sustained clinical remission after treatment, which included an imatinib mesylate regimen. Conclusion This study shows that observations of bone marrow morphology, initial and follow-up cytogenetic studies, and karyotyping of BCR/ABL1 and CBFB/MYH11 provide valuable information for characterizing hematologic malignancies exhibiting t(9;22) and inv(16) coexistence. PMID:24724063

Han, Eunhee; Lee, Hyeyoung; Kim, Yonggoo; Han, Kyungja; Lee, Sung-Eun; Kim, Hee-Je; Kim, Dong-Wook

2014-01-01

309

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

310

The Sex Chromosomes of Silene latifolia Revisited and Revised  

Microsoft Academic Search

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

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

2003-01-01

311

Battle of the sexes: Conflict over dosage-sensitive genes and the origin of X chromosome inactivation  

E-print Network

Battle of the sexes: Conflict over dosage-sensitive genes and the origin of X chromosome, University College London, London WC1E 6BT, United Kingdom M ales have been short-changed in the X chromosome de- partment: they only get one copy of the chromosome and the genes that it carries, whereas females

McLysaght, Aoife

312

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

313

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

314

Spatial dynamics of evolving dosage compensation in a young sex chromosome system.  

PubMed

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

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

2015-02-01

315

Molecular diagnostic testing for Klinefelter syndrome and other male sex chromosome aneuploidies  

PubMed Central

Background Male sex chromosome aneuploidies are underdiagnosed despite concomitant physical and behavioral manifestations. Objective To develop a non-invasive, rapid and high-throughput molecular diagnostic assay for detection of male sex chromosome aneuploidies, including 47,XXY (Klinefelter), 47,XYY, 48,XXYY and 48,XXXY syndromes. Methods The assay utilizes three XYM and four XA markers to interrogate Y:X and X:autosome ratios, respectively. The seven markers were PCR amplified using genomic DNA isolated from a cohort of 323 males with aneuploid (n?=?117) and 46,XY (n?=?206) karyotypes. The resulting PCR products were subjected to Pyrosequencing, a quantitative DNA sequencing method. Results Receiver operator characteristic (ROC) curves were used to establish thresholds for the discrimination of aneuploid from normal samples. The XYM markers permitted the identification of 47,XXY, 48,XXXY and 47,XYY syndromes with 100% sensitivity and specificity in both purified DNA and buccal swab samples. The 48,XXYY karyotype was delineated by XA marker data from 46,XY; an X allele threshold of 43% also permitted detection of 48,XXYY with 100% sensitivity and specificity. Analysis of X chromosome-specific biallelic SNPs demonstrated that 43 of 45 individuals (96%) with 48,XXYY karyotype had two distinct X chromosomes, while 2 (4%) had a duplicate X, providing evidence that 48,XXYY may result from nondisjunction during early mitotic divisions of a 46,XY embryo. Conclusions Quantitative Pyrosequencing, with high-throughput potential, can detect male sex chromosome aneuploidies with 100% sensitivity. PMID:22524164

2012-01-01

316

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

PubMed Central

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

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

2015-01-01

317

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

PubMed Central

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

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

2012-01-01

318

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

PubMed Central

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

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

2014-01-01

319

Imprinted chromosomal regions of the human genome display sex-specific meiotic recombination frequencies  

Microsoft Academic Search

Background: Meiotic recombination events do not occur randomly along a chromosome, but appear to be restricted to specific regions. In addition, some regions in the genome undergo recombination more frequently in the germ cells of one sex than the other. Genomic imprinting, the process by which the two parental alleles of a gene are differentially marked, is another genetic phenomenon

Andràs Pàldi; Gàbor Gyapay; Jacques Jami

1995-01-01

320

Introduction Sex is determined in many organisms by an X-chromosome  

E-print Network

, dosage compensation is achieved by a protein complex that binds to both X chromosomes of hermaphrodites that initiates dosage compensation (Dawes et al., 1999). It is the only dosage compensation protein known between the sexes. To achieve dosage compensation, a large protein complex is targeted to the X

Meyer, Barbara

321

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. PMID:22521361

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

322

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

PubMed

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

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

2009-03-01

323

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

Microsoft Academic Search

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

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

2003-01-01

324

Replication of the heterogeneous heterochromatin of the sex chromosomes of Microtus cabrerae.  

PubMed

We used bromosubstitution to investigate the mode of replication of different types of heterochromatin located in the sex chromosomes of Microtus cabrerae. Our results clearly show that, although the heterochromatin is late replicating, the replication timing of different types of constitutive heterochromatin is related to their banding properties: R-type heterochromatin replicates before G-type heterochromatin, and this replication is asynchronous in both sex chromosomes. Furthermore, the late replication behaviour of the inactive X may spread to its constitutive heterochromatin. In some cells, a region of the constitutive heterochromatin of the late replicating X spontaneously switches to early replication, which may be related to transcriptional activity. Replication behaviour of the constitutive heterochromatin in the Y chromosome is similar to that of the late replicating X. PMID:1473582

Burgos, M; Jiménez, R; Sánchez, A; Díaz de la Guardia, R

1992-12-01

325

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

326

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

327

Cytogenetic abnormalities in benign lymphoid hyperplasia: a dual-parameter study using chromosome analysis and flow cytometry.  

PubMed

This is a prospective study of lymphoid tissue showing benign reactive hyperplasia (18 lymph nodes and 2 tonsils), using cytogenetic analysis of cells stimulated with T- or B-cell mitogens. The reason for this study was the detection of an abnormal chromosomal population in cells from an enlarged lymph node excised from a 7-year-old female who on further investigation was found to be clinically well and after one year's close follow-up had not developed any further signs or symptoms of malignancy. In addition, DNA content was measured by flow cytometry (FCM) on fresh cell suspensions in 17 cases and fixed cell suspensions in 3 cases. Structural and numerical clonal chromosome abnormalities were found in 9 of the 20 samples, but no common specific defect was identified. FCM showed an abnormal DNA content in 10 of the 20 samples studied; 3 of these showed clonal chromosome abnormalities. Surface membrane immunoglobulin studies were carried out on 15 of the 20 samples using cell suspensions and frozen tissue sections. In 5 of the 15 cases, monoclonal surface immunoglobulin was detected. There was no direct correlation between the surface membrane immunoglobulin studies and the chromosome and FCM analyses. We conclude that aneuploidy is a common feature in reactive lymphoid tissue, but both cytogenetics and FCM are needed to identify it. PMID:2606580

Grace, J; Hall, B E; Lew, M; Singh, S; Pittman, S; Palmer, A A; Zbroja, R; Wass, J; Vincent, P C

1989-12-15

328

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

329

Characterization of a complex chromosomal rearrangement using chromosome, FISH, and microarray assays in a girl with multiple congenital abnormalities and developmental delay.  

PubMed

Complex chromosomal rearrangements (CCRs) are balanced or unbalanced structural rearrangements involving three or more cytogenetic breakpoints on two or more chromosomal pairs. The phenotypic anomalies in such cases are attributed to gene disruption, superimposed cryptic imbalances in the genome, and/or position effects. We report a 14-year-old girl who presented with multiple congenital anomalies and developmental delay. Chromosome and FISH analysis indicated a highly complex chromosomal rearrangement involving three chromosomes (3, 7 and 12), seven breakpoints as a result of one inversion, two insertions, and two translocations forming three derivative chromosomes. Additionally, chromosomal microarray study (CMA) revealed two submicroscopic deletions at 3p12.3 (467 kb) and 12q13.12 (442 kb). We postulate that microdeletion within the ROBO1 gene at 3p12.3 may have played a role in the patient's developmental delay, since it has potential activity-dependent role in neurons. Additionally, factors other than genomic deletions such as loss of function or position effects may also contribute to the abnormal phenotype in our patient. PMID:25478007

Hemmat, Morteza; Yang, Xiaojing; Chan, Patricia; McGough, Robert A; Ross, Leslie; Mahon, Loretta W; Anguiano, Arturo L; Boris, Wang T; Elnaggar, Mohamed M; Wang, Jia-Chi J; Strom, Charles M; Boyar, Fatih Z

2014-01-01

330

Characterization of a complex chromosomal rearrangement using chromosome, FISH, and microarray assays in a girl with multiple congenital abnormalities and developmental delay  

PubMed Central

Complex chromosomal rearrangements (CCRs) are balanced or unbalanced structural rearrangements involving three or more cytogenetic breakpoints on two or more chromosomal pairs. The phenotypic anomalies in such cases are attributed to gene disruption, superimposed cryptic imbalances in the genome, and/or position effects. We report a 14-year-old girl who presented with multiple congenital anomalies and developmental delay. Chromosome and FISH analysis indicated a highly complex chromosomal rearrangement involving three chromosomes (3, 7 and 12), seven breakpoints as a result of one inversion, two insertions, and two translocations forming three derivative chromosomes. Additionally, chromosomal microarray study (CMA) revealed two submicroscopic deletions at 3p12.3 (467 kb) and 12q13.12 (442 kb). We postulate that microdeletion within the ROBO1 gene at 3p12.3 may have played a role in the patient’s developmental delay, since it has potential activity-dependent role in neurons. Additionally, factors other than genomic deletions such as loss of function or position effects may also contribute to the abnormal phenotype in our patient. PMID:25478007

2014-01-01

331

Chromosome-wide nucleosome replacement and H3.3 incorporation during mammalian meiotic sex chromosome inactivation.  

PubMed

In mammalian males, the first meiotic prophase is characterized by formation of a separate chromatin domain called the sex body. In this domain, the X and Y chromosomes are partially synapsed and transcriptionally silenced, a process termed meiotic sex-chromosome inactivation (MSCI). Likewise, unsynapsed autosomal chromatin present during pachytene is also silenced (meiotic silencing of unsynapsed chromatin, MSUC). Although it is known that MSCI and MSUC are both dependent on histone H2A.X phosphorylation mediated by the kinase ATR, and cause repressive H3 Lys9 dimethylation, the mechanisms underlying silencing are largely unidentified. Here, we demonstrate an extensive replacement of nucleosomes within unsynapsed chromatin, depending on and initiated shortly after induction of MSCI and MSUC. Nucleosomal eviction results in the exclusive incorporation of the H3.3 variant, which to date has primarily been associated with transcriptional activity. Nucleosomal exchange causes loss and subsequent selective reacquisition of specific histone modifications. This process therefore provides a means for epigenetic reprogramming of sex chromatin presumably required for gene silencing in the male mammalian germ line. PMID:17237782

van der Heijden, Godfried W; Derijck, Alwin A H A; Pósfai, Eszter; Giele, Maud; Pelczar, Pawel; Ramos, Liliana; Wansink, Derick G; van der Vlag, Johan; Peters, Antoine H F M; de Boer, Peter

2007-02-01

332

Sex Chromosomes in the Domestic Fowl (Gallus domesticus), Turkey (Meleagris gallopavo) and the Chinese Pheasant (Phasianus colchicus)  

Microsoft Academic Search

A small W-sex chromosome is described in the female karyotype of the domestic fowl (Gallus domesticus), turkey (Meleagris gallopavo) and pheasant (Phasianus colchicus). In the domestic fowl, the W-chromosome is a small unpaired, metacentric chromosome intermediate in size between the chromosomes of the ninth and the tenth pair. In the female turkey, the W is a sub-metacentric element with an

A. Krishan; R. N. Shoffner

1966-01-01

333

Serial study of the effect of radiotherapy on semen parameters, hamster egg penetration rates, and lymphocyte chromosome abnormalities  

SciTech Connect

This study was designed to assess the long-term effects of radiotherapy (RT) on male fertility and the induction of lymphocyte and sperm chromosome abnormalities. This preliminary report provides information on 11 cancer patients (mainly seminomas) treated by RT (testicular dose, 44 to 499 rads). All 11 men were studied pre-RT and at intervals post-RT. The pre-RT semen profile varied considerably, but, in general, the profile was poor with a mean sperm concentration of 19.4 x 10/sup 6/ ml and a mean hamster egg penetration rate of 5%. One month after RT, the sperm concentration decreased and hamster egg penetration was 0% in all men. At 3 and 12 months post-RT, all but two patients were azoospermic. By 24 months post-RT, 9 of 11 patients had regained sperm production and 5 had sperm capable of hamster egg penetration. The three men who have been studied 36 months post-RT had a mean sperm concentration of 45.3 x 10/sup 6/ ml, and all had positive hamster egg penetration tests, although two of the three men had very low penetration rates (2% and 4%). Lymphocyte chromosome analysis demonstrated a striking frequency of chromosome abnormalities post-RT which decreased with time (pre-RT, 0%; 1 month, 42.4%; 3 months, 24.7%; 12 months, 13.8%; 24 months, 11.2%; and 36 months, 10.0%). Thus, it appears that sperm production starts to recover 2 to 3 years after RT when the frequency of lymphocyte chromosome abnormalities has decreased, but the sperm may not be fully functional at this time, as evidenced by poor rates of hamster egg penetration. Future studies of sperm chromosome analysis in these men will determine whether this impairment of the sperm is associated with meiotic chromosome abnormalities.

Martin, R.H.; Barnes, M.; Arthur, K.; Ringrose, T.; Douglas, G.

1984-02-01

334

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

335

Translocation t(X;10)(p10;p10): a rare chromosomal abnormality in a new born female with acute myeloid leukemia.  

PubMed

Sex chromosomes are infrequently involved in patients with hematologic malignancies. In most instances, the abnormality is either duplication in the q arm or deletion and translocation involving the q13 and q24 regions. We report herein a rare translocation t(X;10)(p10;p10) in a newborn with 2 months and 20 days with acute myeloid leukemia (AML) (FAB, M4). Cytogenetic analysis detected a cell clone with t(X;10)(p10;p10). Thus was confirmed by FISH analysis with whole chromosome painting (WCP) specific for chromosomes X and 10. The patient was treated with chemotherapy, and a complete morphologic and cytogenetic remission was achieved. To our knowledge, our case is the first report of a neonatal AML4 with t(X; 10). The patient had an excellent early response to a salvage AML-type therapy. The prognostic significance of the t(X; 10) in this setting remains unclear. Due to the rarity of this translocation, further cytogenetic and molecular biologic studies are required to elucidate the clinical and molecular significance of this unusual karyotypic finding. PMID:21442316

Bennour, Ayda; Sennana, Halima; Zaier, Monia; Ouahchi, Ines; Mrad, Zannouba; Ben Youssef, Yosra; Khelif, Abderrahim; Saad, Ali

2012-06-01

336

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

PubMed

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

Daish, Tasman; Casey, Aaron; Grützner, Frank

2009-01-01

337

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

338

Biased transmission of sex chromosomes in the aphid Myzus persicae is not associated with reproductive mode.  

PubMed

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

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

2014-01-01

339

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

PubMed Central

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

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

2014-01-01

340

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

341

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

PubMed Central

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

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

2014-01-01

342

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

PubMed Central

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

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

2015-01-01

343

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

PubMed

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

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

2015-01-01

344

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

PubMed Central

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

Xie, Xingmei; Liang, Qiaoyi

2014-01-01

345

A perfect knowledge of the effects of chromosomal abnormalities in domestic animal requi-res an exact determination of the chromosome involved in each type of translocation as well as  

E-print Network

A perfect knowledge of the effects of chromosomal abnormalities in domestic animal requi- res an exact determination of the chromosome involved in each type of translocation as well, the occurate identification by means of new banding methods of the chromosomes involved in each type

Paris-Sud XI, Université de

346

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. PMID:23094017

Katsura, Yukako; Satta, Yoko

2012-01-01

347

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

SciTech Connect

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 1/3,500 males with autosomal recessive FCMD should have abnormal dystrophin. To explain the observation of 3/23 FCMD males with abnormal dystrophin, the authors 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.

Beggs, A.H.; Neumann, P.E.; Anderson, M.S.; Kunkel, L.M. (Harvard Medical School, Boston, MA (United States)); Arahata, Kiichi; Arikawa, Eri; Nonaka, Ikuya (National Inst. of Neuroscience, Tokyo (Japan))

1992-01-15

348

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

349

Chromosome analysis in Pseudopaludicola (Anura, Leiuperidae), with description of sex chromosomes XX/XY in P. saltica.  

PubMed

Taxonomic changes have frequently occurred in the anuran genus Pseudopaludicola as a consequence of high morphological similarity among its species. The present work reports karyotypic analysis of three Pseudopaludicola species sampled in their type locality and four Pseudopaludicola populations from distinct localities, aiming at contributing to the systematics of this genus. Chromosomes were stained with Giemsa or submitted to the silver staining (Ag-NOR) and C-banding techniques. The karyotype was 2n=22 in P. mineira, Pseudopaludicola sp. and two populations of P. saltica. The chromosome pair 8 was heteromorphic in P. saltica, characterizing a XX/XY sex-determination system with telocentric X and submetacentric Y. Highly similar karyotypes with 2n=18 chromosomes were observed in P. canga, P. aff. canga from Barreirinhas, State of Maranhão, Uberlândia, State of Minas Gerais and Icém, State São Paulo. The high similarity among the karyotypes 2n=18 suggested that the populations of P. aff. canga belong to the group 'pusilla', the same group of P. canga. The data demonstrated also that P. aff. canga from Barreirinhas (northeast region) is cytogenetically identical to P. canga with regarding the NOR site position in pair 3 and the presence of a heterochromatic block in the pair 2, whereas P. aff. canga from Uberlândia and Icém (southeast) had the NOR in the pair 9. Moreover, the cytogenetic data discriminated P. mineira and Pseudopaludicola sp. from the previously analyzed species with 22 chromosomes, and suggested that Pseudopaludicola sp. is an undescribed species. Sexual heteromorphic chromosomes are firstly reported in Pseudopaludicola and the data indicated the need of an extensive taxonomic review in this genus. PMID:20536541

Duarte, Thiago C; Veiga-Menoncello, Ana Cristina P; Lima, Janaína F R; Strüssmann, Christine; Del-Grande, Maria L; Giaretta, Ariovaldo A; Pereira, Emiliane G; Rossa-Feres, Denise C; Recco-Pimentel, Shirlei M

2010-04-01

350

Y chromosome haplogroups in autistic subjects  

Microsoft Academic Search

The male to female ratio in autism is 4:1 in the global autistic population, but increases to 23:1 in autistic subjects without physical or brain abnormalities.1 Despite this well-recognised gender difference, male predisposition to autistic disorder remains unexplained and the role of sex chromosomes is still debated. Numerical and structural abnormalities of the sex chromosomes are among the most frequently

S Jamain; H Quach; L Quintana-Murci; C Betancur; A Philippe; C Gillberg; E Sponheim; O H Skjeldal; M Fellous; M Leboyer; T Bourgeron

2002-01-01

351

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

PubMed

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. PMID:21829300

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

2010-01-01

352

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. PMID:21931567

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

2011-01-01

353

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

354

The human sex-reversing ATRX gene has a homologue on the marsupial Y chromosome, ATRY: Implications for the evolution of mammalian sex determination  

Microsoft Academic Search

Mutations in the ATRX gene on the human X chromosome cause X-linked -thalassemia and mental retardation. XY patients with deletions or mutations in this gene display varying degrees of sex reversal, implicating ATRX in the development of the human testis. To explore further the role of ATRX in mammalian sex differentiation, the homologous gene was cloned and characterized in a

Andrew Pask; Marilyn B. Renfree; Jennifer A. Marshall Graves

2000-01-01

355

The study of chromosomal abnormalities and heteromorphism in couples with 2 or 3 recurrent abortions in Shahid Beheshti Hospital of Hamedan  

PubMed Central

Background: Different studies show that chromosomal balance translocation in the parents can cause recurrent spontaneous abortions. Incidence of chromosomal translocation abnormalities in couples with repeated abortions is from 0% to 31%. Objective: The purpose of this research was studying the presence or absence of chromosomal abnormalities and heteromorphism in couples with recurrent abortions and also the role of this anomaly in the abortions. Materials and Methods: This study is a cross sectional descriptive study which have investigated 75 couples who had three abortions or more, and 65 couples who had two abortions that referred by gynecologist to the lab of Beheshti Hospital in Hamedan for cytogenetical investigation. Also 40 healthy individuals without history of abortion investigated as control group.GTG bonding technique (staining banding with gymsa and trypsin) is used in this study. Results:Frequency of chromosomal abnormalities and heteromorphism among couples with three or more abortions were reported respectively 5.3% and 9.3%. This frequency in couples with two abortions was respectively 3.07%and 6.15%. The frequency of chromosomal heteromorphism in control group was 7.5% and no chromosomal abnormalities were observed in them. Conclusion:This study shows that chromosomal abnormality can be one reason of recurrent spontaneous abortions and more abortion increases the probability of this anomaly. Also, existence of chromosomal heteromorphism in the general population without clinical abortion symptoms shows that chromosomal heteromorphism cannot be the reason of these spontaneous abortions. PMID:24639747

Asgari, Atefeh; Ghahremani, Safieh; Saeedi, Solmaz; Kamrani, Ebrahim

2013-01-01

356

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

Microsoft Academic Search

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

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

2008-01-01

357

Heterogeneous heterochromatin and size variation in the sex chromosomes of Microtus cabrerae.  

PubMed

The sex chromosomes of Microtus cabrerae are characterized by large segments of constitutive heterochromatin in both the X and Y. Alkali treatment, enzymatic digestion (trypsin), and fluorochrome staining reveal considerable heterogeneity within these heterochromatic blocks and allow us to distinguish several regions. In addition, variation in the length of these segments is also present, probably as a result of deletions. A possible explanation for the origin of these heterochromatic blocks is discussed. PMID:3281801

Burgos, M; Jiménez, R; Olmos, D M; Diaz de la Guardia, R

1988-01-01

358

Comparison of the Z and W sex chromosomal architectures in elegant crested tinamou ( Eudromia elegans ) and ostrich ( Struthio camelus ) and the process of sex chromosome differentiation in palaeognathous birds  

Microsoft Academic Search

To clarify the process of avian sex chromosome differentiation in palaeognathous birds, we performed molecular and cytogenetic\\u000a characterization of W chromosome-specific repetitive DNA sequences for elegant crested tinamou (Eudromia elegans, Tinamiformes) and constructed comparative cytogenetic maps of the Z and W chromosomes with nine chicken Z-linked gene homologues\\u000a for E. elegans and ostrich (Struthio camelus, Struthioniformes). A novel family of

Yayoi Tsuda; Chizuko Nishida-Umehara; Junko Ishijima; Kazuhiko Yamada; Yoichi Matsuda

2007-01-01

359

Detection of cryptic chromosomal abnormalities in unexplained mental retardation: A general strategy using hypervariable subtelomeric DNA polymorphisms  

SciTech Connect

Given the availability of DNA from both parents, unusual segregation of hypervariable DNA polymorphisms (HVPs) in the offspring may be attributable to deletion, unbalanced chromosomal translocation, or uniparental disomy. The telomeric regions of chromosomes are rich in both genes and hypervariable minisatellite sequences and may also be particularly prone to cryptic breakage events. Here the author describes and analyzes a general approach to the detection of subtelomeric abnormalities and uniparental disomy in patients with unexplained mental retardation. With 29 available polymorphic systems, [approximately]50%-70% of these abnormalities could currently be detected. Development of subtelomeric HVPs physically localized with respect to their telomers should provide a valuable resource in routine diagnostics. 73 refs., 4 figs., 4 tabs.

Wilkie, A.O.M.

1993-09-01

360

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. PMID:23712453

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

361

Masked complex chromosome rearrangement in a child thought to have del(8qter) as the sole cytogenetic abnormality.  

PubMed

Cytogenetic analyses of constitutional diseases have disclosed several chromosomal rearrangements. At the molecular level, these rearrangements often result in the breakage of genes or alteration of genome architecture. Fluorescence in situ hybridization (FISH) and molecular investigations of a patient showing hypotonia and dysmorphic traits revealed a masked complex chromosome abnormality previously detected by G-banding as a simple 8qter deletion. To characterize the genetic rearrangements panels of bacterial artificial chromosomes (BACs) covering 8q24.22-->qter were constructed, and short tandem repeats (STRs) were used to refine the localization of the breakpoints and to assess the parental origin of the defect. Chromosome 8 displayed the breakpoint at 8q24.22 and an unexpected distal breakpoint at 8q24.23 resulting in unbalanced translocation of a small 8q genomic region on the chromosome 16qter. The study of the 16qter region revealed that the 16q subtelomere was retained and the translocated material of distal 8q was juxtaposed. Moreover, molecular analyses showed that part of the translocated 8qter segment on der(16) was partially duplicated, inverted and that the rearrangement arose in the paternal meiosis. These findings emphasize the complexity of some only apparently simple chromosomal rearrangements and suggest a subtelomeric FISH approach to enhance diagnostic care when a cytogenetic terminal deletion is found. PMID:18758162

Surace, C; Digilio, M C; Lombardo, A; Sirleto, P; Tomaiuolo, A C; Roberti, M C; Capolino, R; Angioni, A

2008-01-01

362

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

363

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

PubMed

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

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

2015-01-01

364

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

365

Numerical abnormalities of the Cyclin D 1 gene locus on chromosome 11q13 in non-melanoma skin cancer  

Microsoft Academic Search

Deregulation of the cell-cycle G1-restriction point control via abnormalities of Rb-pathway components is a frequent event in the formation of cancer. The aim of this study was to evaluate numerical aberrations of the Cyclin D1 (CCND1, PRAD1, bcl-1) gene locus at chromosome 11q13 in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) of the skin and to compare it

Jochen Utikal; Martin Udart; Ulrike Leiter; Peter Kaskel; Ralf Uwe Peter; Gertraud Krähn

2005-01-01

366

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

367

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. PMID:24639691

Mirjalili, Tahereh; Kalantar, Seyed Mehdi; Shams Lahijani, Maryam; Sheikhha, Mohamad Hasan; Talebi, Alireza

2013-01-01

368

A sex-linked SCAR marker in Bryonia dioica (Cucurbitaceae), a dioecious species with XY sex-determination and homomorphic sex chromosomes.  

PubMed

Genetic crosses between the dioecious Bryonia dioica (Cucurbitaceae) and the monoecious B. alba in 1903 provided the first clear evidence for Mendelian inheritance of dioecy and made B. dioica the first organism for which XY sex-determination was experimentally proven. Applying molecular tools to this system, we developed a sex-linked sequence-characterized amplified region (SCAR) marker for B. dioica and sequenced it for individuals representing the full geographic range of the species from Scotland to North Africa. For comparison, we also sequenced this marker for representatives of the dioecious B. cretica, B. multiflora and B. syriaca, and monoecious B. alba. In no case did any individual, male or female, yield more than two haplotypes. In northern Europe, we found strong linkage between our marker and sex, with all Y-sequences being identical to each other. In southern Europe, however, the linkage between our marker and sex was weak, with recombination detected within both the X- and the Y-homologues. Population genetic analyses suggest that the SCAR marker experienced different evolutionary pressures in northern and southern Europe. These findings fit with phylogenetic evidence that the XY system in Bryonia is labile and suggest that the genus may be a good system in which to study the early steps of sex chromosome evolution. PMID:19120821

Oyama, R K; Volz, S M; Renner, S S

2009-01-01

369

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

370

XX/XO, a rare sex chromosome system in Potamotrygon freshwater stingray from the Amazon Basin, Brazil.  

PubMed

Potamotrygonidae is a representative family of South American freshwater elasmobranchs. Cytogenetic studies were performed in a Potamotrygon species from the middle Negro River, Amazonas, Brazil, here named as Potamotrygon sp. C. Mitotic and meiotic chromosomes were analyzed using conventional staining techniques, C-banding, and detection of the nucleolus organizing regions (NOR) with Silver nitrate (Ag-NOR). The diploid number was distinct between sexes, with males having 2n = 67 chromosomes, karyotype formula 19m + 8sm + 10st + 30a, and fundamental number (FN) = 104, and females having 2n = 68 chromosomes, karyotype formula 20m + 8sm + 10st + 30a, and FN = 106. A large chromosome, corresponding to pair number two in the female karyotype, was missing in the male complement. Male meiotic cells had 33 bivalents plus a large univalent chromosome in metaphase I, and n = 33 and n = 34 chromosomes in metaphase II. These characteristics are consistent with a sex chromosome system of the XX/XO type. Several Ag-NOR sites were identified in both male and female karyotypes. Positive C-banding was located only in the centromeric regions of the chromosomes. This sex chromosome system, which rarely occurs in fish, is now being described for the first time among the freshwater rays of the Amazon basin. PMID:24068425

de Souza Valentim, Francisco Carlos; Porto, Jorge Ivan Rebelo; Bertollo, Luiz Antonio Carlos; Gross, Maria Claudia; Feldberg, Eliana

2013-09-01

371

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

PubMed

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

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

2008-01-01

372

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. PMID:22013909

2011-01-01

373

Numerical chromosome abnormalities in spermatozoa of fertile and infertile men detected by fluorescence in situ hybridization  

Microsoft Academic Search

Fluorescence in situ hybridization (FISH) with single-color chromosome-specific probes was used to study the rates of disomy for chromosome 1, 16, X, and Y in sperm of fertile and infertile subjects. Diploidy rates were studied using a two-color cocktail of probes for chromosomes 17 and 18 in the same sperm samples. Two-color methodology was not available at the outset of

Norio Miharu; Robert G. Best; S. Robert Young

1994-01-01

374

Differential expression of genes mapping to recurrently abnormal chromosomal regions characterize neuroblastic tumours with distinct ploidy status  

PubMed Central

Background Neuroblastic tumours (NBTs) represent a heterogeneous spectrum of neoplastic diseases associated with multiple genetic alterations. Structural and numerical chromosomal changes are frequent and are predictive parameters of NBTs outcome. We performed a comparative analysis of the biological entities constituted by NBTs with different ploidy status. Methods Gene expression profiling of 49 diagnostic primary NBTs with ploidy data was performed using oligonucleotide microarray. Further analyses using Quantitative Real-Time Polymerase Chain Reaction (Q-PCR); array-Comparative Genomic Hybridization (aCGH); and Fluorescent in situ Hybridization (FISH) were performed to investigate the correlation between aneuploidy, chromosomal changes and gene expression profiles. Results Gene expression profiling of 49 primary near-triploid and near-diploid/tetraploid NBTs revealed distinct expression profiles associated with each NBT subgroup. A statistically significant portion of genes mapped to 1p36 (P = 0.01) and 17p13-q21 (P < 0.0001), described as recurrently altered in NBTs. Over 90% of these genes showed higher expression in near-triploid NBTs and the majority are involved in cell differentiation pathways. Specific chromosomal abnormalities observed in NBTs, 1p loss, 17q and whole chromosome 17 gains, were reflected in the gene expression profiles. Comparison between gene copy number and expression levels suggests that differential expression might be only partly dependent on gene copy number. Intratumoural clonal heterogeneity was observed in all NBTs, with marked interclonal variability in near-diploid/tetraploid tumours. Conclusion NBTs with different cellular DNA content display distinct transcriptional profiles with a significant portion of differentially expressed genes mapping to specific chromosomal regions known to be associated with outcome. Furthermore, our results demonstrate that these specific genetic abnormalities are highly heterogeneous in all NBTs, and suggest that NBTs with different ploidy status may result from different mechanisms of aneuploidy driving tumourigenesis. PMID:18700951

Lavarino, Cinzia; Garcia, Idoia; Mackintosh, Carlos; Cheung, Nai-Kong V; Domenech, Gema; Ríos, José; Perez, Noelia; Rodríguez, Eva; de Torres, Carmen; Gerald, William L; Tuset, Esperanza; Acosta, Sandra; Beleta, Helena; de Álava, Enrique; Mora, Jaume

2008-01-01

375

Analysis of a novel gene, Sdgc, reveals sex chromosome-dependent differences of medaka germ cells prior to gonad formation.  

PubMed

In vertebrates that have been examined to date, the sexual identity of germ cells is determined by the sex of gonadal somatic cells. In the teleost fish medaka, a sex-determination gene on the Y chromosome, DMY/dmrt1bY, is expressed in gonadal somatic cells and regulates the sexual identity of germ cells. Here, we report a novel mechanism by which sex chromosomes cell-autonomously confer sexually different characters upon germ cells prior to gonad formation in a genetically sex-determined species. We have identified a novel gene, Sdgc (sex chromosome-dependent differential expression in germ cells), whose transcripts are highly enriched in early XY germ cells. Chimeric analysis revealed that sexually different expression of Sdgc is controlled in a germ cell-autonomous manner by the number of Y chromosomes. Unexpectedly, DMY/dmrt1bY was expressed in germ cells prior to gonad formation, but knockdown and overexpression of DMY/dmrt1bY did not affect Sdgc expression. We also found that XX and XY germ cells isolated before the onset of DMY/dmrt1bY expression in gonadal somatic cells behaved differently in vitro and were affected by Sdgc. Sdgc maps close to the sex-determination locus, and recombination around the two loci appears to be repressed. Our results provide important insights into the acquisition and plasticity of sexual differences at the cellular level even prior to the developmental stage of sex determination. PMID:25078651

Nishimura, Toshiya; Herpin, Amaury; Kimura, Tetsuaki; Hara, Ikuyo; Kawasaki, Toshihiro; Nakamura, Shuhei; Yamamoto, Yasuhiro; Saito, Taro L; Yoshimura, Jun; Morishita, Shinichi; Tsukahara, Tatsuya; Kobayashi, Satoru; Naruse, Kiyoshi; Shigenobu, Shuji; Sakai, Noriyoshi; Schartl, Manfred; Tanaka, Minoru

2014-09-01

376

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

PubMed

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

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

2013-07-01

377

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. PMID:23733786

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

2013-01-01

378

Sex chromosome phylogenetics indicate a single transition to terrestriality in the guenons (tribe Cercopithecini).  

PubMed

This is the first molecular study to trace the evolutionary transition in substrate preference across a primate radiation. We surveyed 20 guenons (tribe Cercopithecini) and 4 outgroup taxa for two Y-chromosomal genes, TSPY ( approximately 2240 bp) and SRY ( approximately 780 bp), and one X-chromosomal intergenic region ( approximately 1600 bp) homologous to a fragment of human Xq13.3. Parsimony and maximum likelihood analyses of the sex chromosomal datasets consistently cluster the three terrestrial taxa, Cercopithecus aethiops, Cercopithecus lhoesti, and Erythrocebus patas, into a group that is reciprocally monophyletic with a clade of arboreal Cercopithecus spp. Given that the common ancestor of the two clades was most likely an arboreal taxon, this phylogenetic pattern suggests the transition to terrestriality occurred only once among the extant guenons. This pattern also indicates that the genus Cercopithecus is paraphyletic, as presently defined, and calls for taxonomic revision so that the nomen describes a strictly monophyletic group. We outline four acceptable taxonomic schemes and suggest that the most appropriate is to reassign C. aethiops, C. lhoesti, and E. patas to the resurrected genus Chlorocebus. Finally, while the phylogeny and taxonomy of terrestrial guenons were the focus of this study, the X-chromosome sequences presented here represent the first molecular evidence to unambiguously place Allenopithecus nigroviridis as the basal lineage of the tribe Cercopithecini. PMID:14871564

Tosi, Anthony J; Melnick, Don J; Disotell, Todd R

2004-02-01

379

Cytogenetics of bisexual\\/unisexual species of Poecilia. IV. Sex chromosomes, sex chromatin composition and Ag-NOR polymorphisms in Poecilia latipinna: a population from Mexico  

Microsoft Academic Search

Cytogenetic analysis using C-banding, silver staining and fluorescent staining was carried out on a population sample of Poecilia latipinna derived from Tampico, Mexico, to verify the presence of sex chromosomes in individuals from the southern areas of this species range and to investigate the extent of C-band and Ag-NOR polymorphisms. Females were found to have W heteromorphic chromosomes, with large

Luciana Sola; Simona Bressanello; Ellen M Rasch; Paul J Monaco

1993-01-01

380

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

PubMed Central

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

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

2014-01-01

381

Identification of FISH biomarkers to detect chromosome abnormalities associated with prostate adenocarcinoma in tumour and field effect environment  

PubMed Central

Background To reduce sampling error associated with cancer detection in prostate needle biopsies, we explored the possibility of using fluorescence in situ hybridisation (FISH) to detect chromosomal abnormalities in the histologically benign prostate tissue from patients with adenocarcinoma of prostate. Methods Tumour specimens from 33 radical prostatectomy (RP) cases, histologically benign tissue from 17 of the 33 RP cases, and 26 benign prostatic hyperplasia (BPH) control cases were evaluated with Locus Specific Identifier (LSI) probes MYC (8q24), LPL (8p21.22), and PTEN (10q23), as well as with centromere enumerator probes CEP8, CEP10, and CEP7. A distribution of FISH signals in the tumour and histologically benign adjacent tissue was compared to that in BPH specimens using receiver operating characteristic curve analysis. Results The combination of MYC gain, CEP8 Abnormal, PTEN loss or chromosome 7 aneusomy was positive in the tumour area of all of the 33 specimens from patients with adenocarcinomas, and in 88% of adjacent histologically benign regions (15 out of 17) but in only 15% (4 out of 26) of the benign prostatic hyperplasia control specimens. Conclusions A panel of FISH markers may allow detection of genomic abnormalities that associate with adenocarcinoma in the field adjacent to and surrounding the tumour, and thus could potentially indicate the presence of cancer in the specimen even if the cancer focus itself was missed by biopsy and histology review. PMID:24568597

2014-01-01

382

A Sex Chromosomal Restriction-Fragment-Length Marker Linked to Melanoma-Determining Tu Loci in Xiphophorus  

PubMed Central

In Xiphophorus, the causative genetic information for melanoma formation has been assigned by classical genetics to chromosomal loci, which are located on the sex chromosomes. In our attempts to molecularly clone these melanoma-determining loci, named Tu, we have looked for restriction-fragment-length markers (RFLMs) linked to the Tu loci. These RFLMs should be useful in obtaining a physical map of a Tu locus, which will aid in the cloning of the corresponding sequences. DNA samples from various Xiphophorus strains and hybrids including those bearing different Tu wild-type, deletion and translocation chromosomes, were screened for the presence of random RFLMs using homologous or heterologous sequences as hybridization probes. We find an EcoRI restriction fragment which shows limited crosshybridization to the v-erb B gene--but not representing the authentic c-erb B gene of Xiphophorus--to be polymorphic with respect to different sex chromosomes. Linkage analysis revealed that a 5-kb fragment is linked to the Tu-Sd locus on the X chromosome, a 7-kb fragment is linked to the Tu-Sr locus on the Y chromosome, both of Xiphophorus maculatus, and that a 12-kb fragment is linked to the Tu-Li locus on the X chromosome of Xiphophorus variatus. Using different chromosomal mutants this RFLM has been mapped to a frequent deletion/translocation breakpoint of the X chromosome, less than 0.3 cM apart from the Tu locus. PMID:2841190

Schartl, M.

1988-01-01

383

A sex chromosomal restriction-fragment-length marker linked to melanoma-determining Tu loci in Xiphophorus.  

PubMed

In Xiphophorus, the causative genetic information for melanoma formation has been assigned by classical genetics to chromosomal loci, which are located on the sex chromosomes. In our attempts to molecularly clone these melanoma-determining loci, named Tu, we have looked for restriction-fragment-length markers (RFLMs) linked to the Tu loci. These RFLMs should be useful in obtaining a physical map of a Tu locus, which will aid in the cloning of the corresponding sequences. DNA samples from various Xiphophorus strains and hybrids including those bearing different Tu wild-type, deletion and translocation chromosomes, were screened for the presence of random RFLMs using homologous or heterologous sequences as hybridization probes. We find an EcoRI restriction fragment which shows limited crosshybridization to the v-erb B gene--but not representing the authentic c-erb B gene of Xiphophorus--to be polymorphic with respect to different sex chromosomes. Linkage analysis revealed that a 5-kb fragment is linked to the Tu-Sd locus on the X chromosome, a 7-kb fragment is linked to the Tu-Sr locus on the Y chromosome, both of Xiphophorus maculatus, and that a 12-kb fragment is linked to the Tu-Li locus on the X chromosome of Xiphophorus variatus. Using different chromosomal mutants this RFLM has been mapped to a frequent deletion/translocation breakpoint of the X chromosome, less than 0.3 cM apart from the Tu locus. PMID:2841190

Schartl, M

1988-07-01

384

Getting a Full Dose? Reconsidering Sex Chromosome Dosage Compensation in the Silkworm, Bombyx mori  

E-print Network

://creativecommons.org/licenses/by-nc/ 2.5), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Genome Biol. Evol. 3:491–504. doi:10.1093/gbe/evr036 Advance Access publication April 20, 2011 491 GBE... at U niversity of K ansas Libraries on M arch 3, 2015 http://gbe.oxfordjournals.org/ D ow nloaded from between sex chromosomes. However, this explanation ob- scures a subtle but fundamental distinction between how dosage compensation is diagnosed...

Walters, James R.; Hardcastle, Thomas J.

2011-04-20

385

Multiple nuclear gene phylogenetic analysis of the evolution of dioecy and sex chromosomes in the genus Silene.  

PubMed

In the plant genus Silene, separate sexes and sex chromosomes are believed to have evolved twice. Silene species that are wholly or largely hermaphroditic are assumed to represent the ancestral state from which dioecy evolved. This assumption is important for choice of outgroup species for inferring the genetic and chromosomal changes involved in the evolution of dioecy, but is mainly based on data from a single locus (ITS). To establish the order of events more clearly, and inform outgroup choice, we therefore carried out (i) multi-nuclear-gene phylogenetic analyses of 14 Silene species (including 7 hermaphrodite or gynodioecious species), representing species from both Silene clades with dioecious members, plus a more distantly related outgroup, and (ii) a BayesTraits character analysis of the evolution of dioecy. We confirm two origins of dioecy within this genus in agreement with recent work on comparing sex chromosomes from both clades with dioecious species. We conclude that sex chromosomes evolved after the origin of Silene and within a clade that includes only S. latifolia and its closest relatives. We estimate that sex chromosomes emerged soon after the split with the ancestor of S. viscosa, the probable closest non-dioecious S. latifolia relative among the species included in our study. PMID:21853022

Marais, Gabriel A B; Forrest, Alan; Kamau, Esther; Käfer, Jos; Daubin, Vincent; Charlesworth, Deborah

2011-01-01

386

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. PMID:21853022

Marais, Gabriel A. B.; Forrest, Alan; Kamau, Esther; Käfer, Jos; Daubin, Vincent; Charlesworth, Deborah

2011-01-01

387

Is the rate of insertion and deletion mutation male biased?: Molecular evolutionary analysis of avian and primate sex chromosome sequences.  

PubMed Central

The rate of mutation for nucleotide substitution is generally higher among males than among females, likely owing to the larger number of DNA replications in spermatogenesis than in oogenesis. For insertion and deletion (indel) mutations, data from a few human genetic disease loci indicate that the two sexes may mutate at similar rates, possibly because such mutations arise in connection with meiotic crossing over. To address origin- and sex-specific rates of indel mutation we have conducted the first large-scale molecular evolutionary analysis of indels in noncoding DNA sequences from sex chromosomes. The rates are similar on the X and Y chromosomes of primates but about twice as high on the avian Z chromosome as on the W chromosome. The fact that indels are not uncommon on the nonrecombining Y and W chromosomes excludes meiotic crossing over as the main cause of indel mutation. On the other hand, the similar rates on X and Y indicate that the number of DNA replications (higher for Y than for X) is also not the main factor. Our observations are therefore consistent with a role of both DNA replication and recombination in the generation of short insertion and deletion mutations. A significant excess of deletion compared to insertion events is observed on the avian W chromosome, consistent with gradual DNA loss on a nonrecombining chromosome. PMID:12750337

Sundström, Hannah; Webster, Matthew T; Ellegren, Hans

2003-01-01

388

Characterization and description of a multiple sex chromosome system in Potamotrygon motoro (Chondrichthyes, Myliobatiformes) from the Paraná River, Argentina.  

PubMed

The Potamotrygonidae family represents the only freshwater group of specialized elasmobranchs and is composed of 4 genera: Plesiotrygon, Paratrygon, Potamotrygon, and Heliotrygon. Individuals of Potamotrygon motoro were collected from the Paraná River at Ituzaingó (Province of Corrientes) in Argentina. Mitotic preparations were obtained using direct techniques and lymphocyte cultures. Chromosomes were studied with conventional Giemsa, C-band and nucleolus organizer region stainings. The diploid number and karyotype formulae were 2n = 66 with 33 homomorphic pairs (14M + 16SM + 22ST + 14A) in females and 2n = 65 with 31 homomorphic pairs plus 3 heteromorphic chromosomes (13M + 15SM + 23ST + 14A) in males. Heterochromatin was distributed at the pericentromeric regions of almost all chromosomes and in the telomeric and interstitial positions of some chromosomes. nucleolus organizer regions were multiple and located at telomeric regions. Because of the clear karyotype differences between the 2 sexes and the presence of 3 unpaired chromosomes in males, it is possible to suggest the occurrence of a multiple sex chromosome system, with male heterogamety (X1X1X2X2/X1X2Y). Further cytogenetic studies are required to develop a hypothesis about the origin of the multiple sex chromosome system in P. motoro. PMID:23359059

Aichino, D R; Pastori, M C; Roncati, H A; Ledesma, M A; Swarça, A C; Fenocchio, A S

2013-01-01

389

The effects of male aging on semen quality, sperm DNA fragmentation and chromosomal abnormalities in an infertile population  

Microsoft Academic Search

Purpose  To investigate the effects of male aging on semen quality, DNA fragmentation and chromosomal abnormalities in the spermatozoa\\u000a of infertile patients and fertile men.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Semen samples of 140 infertile patients (24–76 years) and 50 men with proven fertility (25–65 years) were analyzed according\\u000a to WHO guidelines. DNA fragmentation was detected by TUNEL assay, while aneuploidy was assessed by FISH.\\u000a \\u000a \\u000a \\u000a \\u000a Results  In the patient

Sonia Brahem; Meriem Mehdi; Hatem Elghezal; Ali Saad

2011-01-01

390

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

PubMed Central

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 abnormalities at two loci and the mutational status of p53. Gain at 8q24 and loss at 5q15-5q21 are linked with mutant p53. The 9q and 5q losses suggest the possibility of gene products involved in breast cancer progression. The analytical techniques are general and also are applicable to the analysis of array-based expression data. PMID:11438741

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

2001-01-01

391

MECP2 duplications in six patients with complex sex chromosome rearrangements  

PubMed Central

Duplications of the Xq28 chromosome region resulting in functional disomy are associated with a distinct clinical phenotype characterized by infantile hypotonia, severe developmental delay, progressive neurological impairment, absent speech, and proneness to infections. Increased expression of the dosage-sensitive MECP2 gene is considered responsible for the severe neurological impairments observed in affected individuals. Although cytogenetically visible duplications of Xq28 are well documented in the published literature, recent advances using array comparative genomic hybridization (CGH) led to the detection of an increasing number of microduplications spanning MECP2. In rare cases, duplication results from intrachromosomal rearrangement between the X and Y chromosomes. We report six cases with sex chromosome rearrangements involving duplication of MECP2. Cases 1–4 are unbalanced rearrangements between X and Y, resulting in MECP2 duplication. The additional Xq material was translocated to Yp in three cases (cases 1–3), and to the heterochromatic region of Yq12 in one case (case 4). Cases 5 and 6 were identified by array CGH to have a loss in copy number at Xp and a gain in copy number at Xq28 involving the MECP2 gene. In both cases, fluorescent in situ hybridization (FISH) analysis revealed a recombinant X chromosome containing the duplicated material from Xq28 on Xp, resulting from a maternal pericentric inversion. These cases add to a growing number of MECP2 duplications that have been detected by array CGH, while demonstrating the value of confirmatory chromosome and FISH studies for the localization of the duplicated material and the identification of complex rearrangements. PMID:21119712

Breman, Amy M; Ramocki, Melissa B; Kang, Sung-Hae L; Williams, Misti; Freedenberg, Debra; Patel, Ankita; Bader, Patricia I; Cheung, Sau Wai

2011-01-01

392

Morphometric differentiation in Cornops aquaticum (Orthoptera: Acrididae): associations with sex, chromosome, and geographic conditions.  

PubMed

The water-hyacinth grasshopper Cornops aquaticum (Bruner) (Orthoptera: Acrididae) is native to South America and inhabits lowlands from southern Mexico to central Argentina and Uruguay. This grasshopper feeds and lays eggs on species from the genera Eichhornia and Pontederia. Particularly, Eichhornia crassipes is considered "the world's worst water weed," and the release of C. aquaticum was proposed as a form of biological control. Morphometric variation on the chromosomally differentiated populations from the middle and lower Paraná River and its possible association with geographic, sex, and chromosomal conditions was analyzed. Significant phenotype variation in C. aquaticum population was detected. C. aquaticum presents body-size sexual dimorphism, females being bigger than males. Female-biased sexual size dimorphism for all five analyzed traits was detected. The assessment of variation in sexual size dimorphism for tegmen length showed that this trait scaled allometrically, indicating that males and females did not vary in a similar fashion. The detected allometry was consistent with Rensch's rule demonstrating greater evolutionary divergence in male size than in female size and suggests that males are more sensitive to environmental condition. The analysis of morphometric variation in the context of chromosome constitution showed that the presence of fusion 1/6 was related to body-size variation. Fusion carriers displayed bigger body size than standard homozygotes. Besides, a positive relationship between tegmen length and the number of fused chromosomes was detected, showing a chromosome dose effect. Because the highest frequency of fusions has been found in the lower Paraná River, a marginal environment for this species, the results found would support the hypothesis that some supergenes located in the fusions may be favored in the southern populations, thus contributing to the establishment and maintenance of the polymorphism. PMID:25399431

Romero, María Luciana; Colombo, Pablo César; Remis, María Isabel

2014-01-01

393

Msh2 deficiency leads to chromosomal abnormalities, centrosome amplification, and telomere capping defect  

SciTech Connect

Msh2 is a key mammalian DNA mismatch repair (MMR) gene and mutations or deficiencies in mammalian Msh2 gene result in microsatellite instability (MSI+) and the development of cancer. Here, we report that primary mouse embryonic fibroblasts (MEFs) deficient in the murine MMR gene Msh2 (Msh2-/-) showed a significant increase in chromosome aneuploidy, centrosome amplification, and defective mitotic spindle organization and unequal chromosome segregation. Although Msh2-/- mouse tissues or primary MEFs had no apparent change in telomerase activity, telomere length, or recombination at telomeres, Msh2-/- MEFs showed an increase in chromosome end-to-end fusions or chromosome ends without detectable telomeric DNA. These data suggest that MSH2 helps to maintain genomic stability through the regulation of the centrosome and normal telomere capping in vivo and that defects in MMR can contribute to oncogenesis through multiple pathways.

Wang, Yisong [ORNL; Liu, Yie [ORNL

2006-01-01

394

Marker chromosomes lacking {alpha}-satellite DNA: A new intriguing class of abnormalities  

SciTech Connect

Recent studies have implicated {alpha}-satellite DNA as an integral part of the centromere and important for the normal segregation of chromosomes. We analyzed four supernumerary marker chromosomes in which fluorescence in situ hybridization (FISH) could detect neither pancentromeric or chromosome specific {alpha}-satellite DNA. Mosaicism of the markers existed, but each was present in the majority of cells indicating that they segregated normally. FISH with chromosome-specific libraries identified the origins of these markers as chromosomes 13 (1 case) and 15 (3 cases). High resolution analysis, combined with hybridization of a series of cosmid probes, revealed that each marker was a symmetrical duplication of the terminal long arm of the parent chromosome. Telomeric sequences were detected by FISH indicating linear structures. Breakpoint heterogeneity, as defined by cosmid probes, was demonstrated in the three cases involving chromosome 15. No pericentromeric satellite III DNA could be detected on three markers. Studies with anti-centromere antibodies are in progress to assay for centromeric antigens on the markers, as expected at functional centromeric sites. Our results demonstrate that the precise structural identification and heterogeneity of these markers can be easily elucidated using FISH with unique sequence cosmid probes. We conclude from our studies and others in the literature: (1) there is a newly defined class of markers lacking {alpha}-satellite DNA and containing duplications of terminal sequences; (2)neither {alpha}-satellite nor satellite III DNA at levels detectable by FISH is necessary for fidelity in the normal segregation of chromosomes; and (3) these markers were most likely formed by recombination of the long arms during meiosis.

Becker, L.A.; Zinn, A.B.; Stallard, J.R. [Case Western Reserve Univ., Cleveland, OH (United States)] [and others

1994-09-01

395

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  

PubMed Central

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 pentasomy X/Y-aneuploidy. The current research sought to fill this gap in the literature and to examine dosage effects of X- and Y-chromosomes on language and social functioning. Methods Participants included 110 youth with X/Y-aneuploidies (32 female) and 52 with typical development (25 female) matched on age (mean~12 years; range 4–22) and maternal education. Participants completed the Wechsler intelligence scales and parents completed the Children’s Communication Checklist-2 and the Social Responsiveness Scale to assess language skills and autistic traits, respectively. Results Both supernumerary X- and Y-chromosomes were related to depressed structural and pragmatic language skills and increased autistic traits. The addition of a Y-chromosome had a disproportionately greater impact on pragmatic language; the addition of one or more X-chromosomes had a disproportionately greater impact on structural language. Conclusions Given that we link extra X-chromosomes with structural language impairments and an extra Y-chromosome with pragmatic language impairments, X/Y-aneuploidies may provide clues to genetic mechanisms contributing to idiopathic language impairment and autism spectrum disorders. PMID:22827287

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

2012-01-01

396

Characterization of the temporal persistence of chromosomal abnormalities in the semen of Hodkin`s disease patients after treatment with NOVP chemotherapy using multi-chromosome fluorescence in situ hybridization  

SciTech Connect

Three-chromosome fluorescence in situ hybridization (FISH) was applied to sperm of men with Hodgkin`s disease to measure the persistence of chromosomally abnormal sperm within the time interval of 3 to 33 months after the end of treatment. NOVP chemotherapy includes the agents novantrone, oncovin, vinblastine, and prednisone, two of which are spindle poisons expected to induce aneuploidy. Semen samples were evaluated for the frequencies of fluorescence phenotypes representing hyperhaploidy, hypohaploidy, and genomic duplications using DNA probes specific for repetitive sequences on chromosomes X,Y, and 8. Using this procedure, NOVP was previously shown to induce chromosomally abnormal sperm in treated patients. In a longitudinal assessment of 11 semen samples from 2 men, frequencies of abnormal sperm appeared to return to pre-treatment levels at {approximately}6 months after the end of treatment and remained at these levels up to 33 months after the end of treatment. However, pre-treatment frequencies of chromosomally abnormal cells in Hodgkin`s patients were elevated above those found in normal healthy men. Additional patients are being evaluated to determine how long after therapy Hodgkin`s disease patients remain at increased risk for producing chromosomally abnormal sperm.

Cassel, M.J.; Robbins, W.A.; Wyrobek, A.J. [Lawrence Livermore National Laboratory, CA (United States); Meistrich, M.L. [Univ. of Texas, Houston, TX (United States)

1994-12-31

397

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

398

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. PMID:9927468

Gutbrod, H; Schartl, M

1999-01-01

399

Polymorphic karyotypes and sex chromosomes in the tufted deer (Elaphodus cephalophus): cytogenetic studies and analyses of sex chromosome-linked genes  

Microsoft Academic Search

Different diploid chromosome numbers have been reported for the tufted deer Elaphodus cephalophus (female, 2n = 46\\/47; male, 2n = 47\\/48) in earlier reports. In the present study, chromosomal analysis of seven tufted deer (5?, 2?) revealed that the karyotype of these animals contains 48 chromosomes, including a pair of large heteromorphic chromosomes in the male. C-banding revealed these chromosomes

X. Cao; H. Jiang; X. Zhang

2005-01-01

400