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Sample records for sex chromosome linked

  1. 3. Pattern of Inheritance of Autosome and Sex. Chromosome Linked ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 10. Teaching and Learning Genetics with Drosophila – Pattern of Inheritance of Autosome and Sex Chro-mosome Linked Genes/Characters. H A Ranganath M T Tanuja. Classroom Volume 4 Issue 10 October 1999 pp 78-87 ...

  2. Molecular analysis of sex chromosome-linked mutants in the ...

    Indian Academy of Sciences (India)

    2010-09-06

    Sep 6, 2010 ... 1Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, ... In Bombyx mori, the W chromosome determines the female sex. .... located on an autosome, and there is no difference in the ex- ..... tral nervous system or in a brain-controlled body wall muscle.

  3. Sex-linked dominant

    Science.gov (United States)

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  4. Sex Reversal and Comparative Data Undermine the W Chromosome and Support Z-linked DMRT1 as the Regulator of Gonadal Sex Differentiation in Birds.

    Science.gov (United States)

    Hirst, Claire E; Major, Andrew T; Ayers, Katie L; Brown, Rosie J; Mariette, Mylene; Sackton, Timothy B; Smith, Craig A

    2017-09-01

    The exact genetic mechanism regulating avian gonadal sex differentiation has not been completely resolved. The most likely scenario involves a dosage mechanism, whereby the Z-linked DMRT1 gene triggers testis development. However, the possibility still exists that the female-specific W chromosome may harbor an ovarian determining factor. In this study, we provide evidence that the universal gene regulating gonadal sex differentiation in birds is Z-linked DMRT1 and not a W-linked (ovarian) factor. Three candidate W-linked ovarian determinants are HINTW, female-expressed transcript 1 (FET1), and female-associated factor (FAF). To test the association of these genes with ovarian differentiation in the chicken, we examined their expression following experimentally induced female-to-male sex reversal using the aromatase inhibitor fadrozole (FAD). Administration of FAD on day 3 of embryogenesis induced a significant loss of aromatase enzyme activity in female gonads and masculinization. However, expression levels of HINTW, FAF, and FET1 were unaltered after experimental masculinization. Furthermore, comparative analysis showed that FAF and FET1 expression could not be detected in zebra finch gonads. Additionally, an antibody raised against the predicted HINTW protein failed to detect it endogenously. These data do not support a universal role for these genes or for the W sex chromosome in ovarian development in birds. We found that DMRT1 (but not the recently identified Z-linked HEMGN gene) is male upregulated in embryonic zebra finch and emu gonads, as in the chicken. As chicken, zebra finch, and emu exemplify the major evolutionary clades of birds, we propose that Z-linked DMRT1, and not the W sex chromosome, regulates gonadal sex differentiation in birds. Copyright © 2017 Endocrine Society.

  5. Sex chromosomes in Ephestia kuehniella

    Czech Academy of Sciences Publication Activity Database

    Marec, František; Sahara, K.; Traut, W.

    2001-01-01

    Roč. 44, č. 1 (2001), s. 131 ISSN 0003-3995. [European Cytogenetics Conference /3./. 07.07.2001-10.07.2001, Paris] Institutional research plan: CEZ:AV0Z5007907 Keywords : Telomere * sex chromosomes * chromosome fragments Subject RIV: EB - Genetics ; Molecular Biology

  6. On the origin of sex chromosomes from meiotic drive

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Joseph A Ross

    2009-02-01

    Full Text Available 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(1X(2Y 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.

  8. Conservation of sex chromosomes in lacertid lizards

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Vukič, J.; Altmanová, M.; Johnson Pokorná, Martina; Moravec, J.; Kratochvíl, L.

    2016-01-01

    Roč. 25, č. 13 (2016), s. 3120-3126 ISSN 0962-1083 Institutional support: RVO:67985904 Keywords : lizards * molecular sex ing * reptiles * sex chromosomes Subject RIV: EG - Zoology Impact factor: 6.086, year: 2016

  9. Abnormal sex chromosome constitution and longitudinal growth

    DEFF Research Database (Denmark)

    Aksglaede, Lise; Skakkebaek, Niels E; Juul, Anders

    2008-01-01

    Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles.......Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles....

  10. New Y chromosomes and early stages of sex chromosome ...

    Indian Academy of Sciences (India)

    2010-09-06

    Sep 6, 2010 ... chromosomes are evolutionary consequences of that func- tion. Given sufficient ... (for a review, see Charlesworth et al. 2005). ... In the present paper, I review sex deter- mination .... part had apparently been exchanged against the homologous ... age group III-Y chromosomes were successful while in well-.

  11. Temporal genomic evolution of bird sex chromosomes

    DEFF Research Database (Denmark)

    Wang, Zongji; Zhang, Jilin; Yang, Wei

    2014-01-01

    BACKGROUND: Sex chromosomes exhibit many unusual patterns in sequence and gene expression relative to autosomes. Birds have evolved a female heterogametic sex system (male ZZ, female ZW), through stepwise suppression of recombination between chrZ and chrW. To address the broad patterns and complex...... driving forces of Z chromosome evolution, we analyze here 45 newly available bird genomes and four species' transcriptomes, over their course of recombination loss between the sex chromosomes. RESULTS: We show Z chromosomes in general have a significantly higher substitution rate in introns and synonymous...... ('fast-Z' evolution). And species with a lower level of intronic heterozygosities tend to evolve even faster on the Z chromosome. Further analysis of fast-evolving genes' enriched functional categories and sex-biased expression patterns support that, fast-Z evolution in birds is mainly driven by genetic...

  12. Evolutionary stability of sex chromosomes in snakes.

    Science.gov (United States)

    Rovatsos, Michail; Vukić, Jasna; Lymberakis, Petros; Kratochvíl, Lukáš

    2015-12-22

    Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms. © 2015 The Author(s).

  13. Why Do Sex Chromosomes Stop Recombining?

    Science.gov (United States)

    Ponnikas, Suvi; Sigeman, Hanna; Abbott, Jessica K; Hansson, Bengt

    2018-04-28

    It is commonly assumed that sex chromosomes evolve recombination suppression because selection favours linkage between sex-determining and sexually antagonistic genes. However, although the role of sexual antagonism during sex chromosome evolution has attained strong support from theory, experimental and observational evidence is rare or equivocal. Here, we highlight alternative, often neglected, hypotheses for recombination suppression on sex chromosomes, which invoke meiotic drive, heterozygote advantage, and genetic drift, respectively. We contrast the hypotheses, the situations when they are likely to be of importance, and outline why it is surprisingly difficult to test them. Lastly, we discuss future research directions (including modelling, population genomics, comparative approaches, and experiments) to disentangle the different hypotheses of sex chromosome evolution. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. A rearrangement of the Z chromosome topology influences the sex-linked gene display in the European corn borer, Ostrinia nubilalis

    Science.gov (United States)

    The sex determination system of Lepidoptera is comprised of heterogametic females (ZW) and homogametic males (ZZ), where voltinism (Volt) and the male pheromone response traits (Resp) are controlled by genes housed on the Z-chromosome. Volt and Resp determine traits that lead to ecotype differentia...

  15. Sex Determination, Sex Chromosomes, and Karyotype Evolution in Insects.

    Science.gov (United States)

    Blackmon, Heath; Ross, Laura; Bachtrog, Doris

    2017-01-01

    Insects harbor a tremendous diversity of sex determining mechanisms both within and between groups. For example, in some orders such as Hymenoptera, all members are haplodiploid, whereas Diptera contain species with homomorphic as well as male and female heterogametic sex chromosome systems or paternal genome elimination. We have established a large database on karyotypes and sex chromosomes in insects, containing information on over 13000 species covering 29 orders of insects. This database constitutes a unique starting point to report phylogenetic patterns on the distribution of sex determination mechanisms, sex chromosomes, and karyotypes among insects and allows us to test general theories on the evolutionary dynamics of karyotypes, sex chromosomes, and sex determination systems in a comparative framework. Phylogenetic analysis reveals that male heterogamety is the ancestral mode of sex determination in insects, and transitions to female heterogamety are extremely rare. Many insect orders harbor species with complex sex chromosomes, and gains and losses of the sex-limited chromosome are frequent in some groups. Haplodiploidy originated several times within insects, and parthenogenesis is rare but evolves frequently. Providing a single source to electronically access data previously distributed among more than 500 articles and books will not only accelerate analyses of the assembled data, but also provide a unique resource to guide research on which taxa are likely to be informative to address specific questions, for example, for genome sequencing projects or large-scale comparative studies. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Neo-sex Chromosomes in the Monarch Butterfly, Danaus plexippus

    Directory of Open Access Journals (Sweden)

    Andrew J. Mongue

    2017-10-01

    Full Text Available We report the discovery of a neo-sex chromosome in the monarch butterfly, Danaus plexippus, and several of its close relatives. Z-linked scaffolds in the D. plexippus genome assembly were identified via sex-specific differences in Illumina sequencing coverage. Additionally, a majority of the D. plexippus genome assembly was assigned to chromosomes based on counts of one-to-one orthologs relative to the butterfly Melitaea cinxia (with replication using two other lepidopteran species, in which genome scaffolds have been mapped to linkage groups. Sequencing coverage-based assessments of Z linkage combined with homology-based chromosomal assignments provided strong evidence for a Z-autosome fusion in the Danaus lineage, involving the autosome homologous to chromosome 21 in M. cinxia. Coverage analysis also identified three notable assembly errors resulting in chimeric Z-autosome scaffolds. Cytogenetic analysis further revealed a large W chromosome that is partially euchromatic, consistent with being a neo-W chromosome. The discovery of a neo-Z and the provisional assignment of chromosome linkage for >90% of D. plexippus genes lays the foundation for novel insights concerning sex chromosome evolution in this female-heterogametic model species for functional and evolutionary genomics.

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

    Science.gov (United States)

    Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

    2013-01-01

    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

  18. Sex chromosomes and speciation in Drosophila

    Science.gov (United States)

    Presgraves, Daven C.

    2010-01-01

    Two empirical rules suggest that sex chromosomes play a special role in speciation. The first is Haldane's rule— the preferential sterility and inviability of species hybrids of the heterogametic (XY) sex. The second is the disproportionately large effect of the X chromosome in genetic analyses of hybrid sterility. Whereas the causes of Haldane's rule are well established, the causes of the ‘large X-effect’ have remained controversial. New genetic analyses in Drosophila confirm that the X is a hotspot for hybrid male sterility factors, providing a proximate explanation for the large X-effect. Several other new findings— on faster X evolution, X chromosome meiotic drive, and the regulation of the X chromosome in the male-germline— provide plausible evolutionary explanations for the large X-effect. PMID:18514967

  19. Mutational landscape of the human Y chromosome-linked genes ...

    Indian Academy of Sciences (India)

    Mutational landscape of the human Y chromosome-linked genes and loci in patients with hypogonadism. Deepali Pathak, Sandeep Kumar Yadav, Leena Rawal and Sher Ali. J. Genet. 94, 677–687. Table 1. Details showing age, sex, karyotype, clinical features and diagnosis results of the patients with H. Hormone profile.

  20. Female meiotic sex chromosome inactivation in chicken.

    Directory of Open Access Journals (Sweden)

    Sam Schoenmakers

    2009-05-01

    Full Text Available 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, gammaH2AX, 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 gammaH2AX 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 gammaH2AX 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.

  1. The variability is in the sex chromosomes.

    Science.gov (United States)

    Reinhold, Klaus; Engqvist, Leif

    2013-12-01

    Sex differences in the mean trait expression are well documented, not only for traits that are directly associated with reproduction. Less is known about how the variability of traits differs between males and females. In species with sex chromosomes and dosage compensation, the heterogametic sex is expected to show larger trait variability ("sex-chromosome hypothesis"), yet this central prediction, based on fundamental genetic principles, has never been evaluated in detail. Here we show that in species with heterogametic males, male variability in body size is significantly larger than in females, whereas the opposite can be shown for species with heterogametic females. These results support the prediction of the sex-chromosome hypothesis that individuals of the heterogametic sex should be more variable. We argue that the pattern demonstrated here for sex-specific body size variability is likely to apply to any trait and needs to be considered when testing predictions about sex-specific variability and sexual selection. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  2. Klinefelter syndrome and other sex chromosomal aneuploidies

    Directory of Open Access Journals (Sweden)

    Graham John M

    2006-10-01

    Full Text Available Abstract The term Klinefelter syndrome (KS describes a group of chromosomal disorder in which there is at least one extra X chromosome to a normal male karyotype, 46,XY. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with 48,XXYY and 48,XXXY being present in 1 per 17,000 to 1 per 50,000 male births. The incidence of 49,XXXXY is 1 per 85,000 to 100,000 male births. In addition, 46,XX males also exist and it is caused by translocation of Y material including sex determining region (SRY to the X chromosome during paternal meiosis. Formal cytogenetic analysis is necessary to make a definite diagnosis, and more obvious differences in physical features tend to be associated with increasing numbers of sex chromosomes. If the diagnosis is not made prenatally, 47,XXY males may present with a variety of subtle clinical signs that are age-related. In infancy, males with 47,XXY may have chromosomal evaluations done for hypospadias, small phallus or cryptorchidism, developmental delay. The school-aged child may present with language delay, learning disabilities, or behavioral problems. The older child or adolescent may be discovered during an endocrine evaluation for delayed or incomplete pubertal development with eunuchoid body habitus, gynecomastia, and small testes. Adults are often evaluated for infertility or breast malignancy. Androgen replacement therapy should begin at puberty, around age 12 years, in increasing dosage sufficient to maintain age appropriate serum concentrations of testosterone, estradiol, follicle stimulating hormone (FSH, and luteinizing hormone (LH. The effects on physical and cognitive development increase with the number of extra Xs, and each extra X is associated with an intelligence quotient (IQ decrease of approximately 15–16 points, with language most affected

  3. SEX-DETector: A Probabilistic Approach to Study Sex Chromosomes in Non-Model Organisms

    Science.gov (United States)

    Muyle, Aline; Käfer, Jos; Zemp, Niklaus; Mousset, Sylvain; Picard, Franck; Marais, Gabriel AB

    2016-01-01

    We propose a probabilistic framework to infer autosomal and sex-linked genes from RNA-seq data of a cross for any sex chromosome type (XY, ZW, and UV). Sex chromosomes (especially the non-recombining and repeat-dense Y, W, U, and V) are notoriously difficult to sequence. Strategies have been developed to obtain partially assembled sex chromosome sequences. Most of them remain difficult to apply to numerous non-model organisms, either because they require a reference genome, or because they are designed for evolutionarily old systems. Sequencing a cross (parents and progeny) by RNA-seq to study the segregation of alleles and infer sex-linked genes is a cost-efficient strategy, which also provides expression level estimates. However, the lack of a proper statistical framework has limited a broader application of this approach. Tests on empirical Silene data show that our method identifies 20–35% more sex-linked genes than existing pipelines, while making reliable inferences for downstream analyses. Approximately 12 individuals are needed for optimal results based on simulations. For species with an unknown sex-determination system, the method can assess the presence and type (XY vs. ZW) of sex chromosomes through a model comparison strategy. The method is particularly well optimized for sex chromosomes of young or intermediate age, which are expected in thousands of yet unstudied lineages. Any organisms, including non-model ones for which nothing is known a priori, that can be bred in the lab, are suitable for our method. SEX-DETector and its implementation in a Galaxy workflow are made freely available. PMID:27492231

  4. Chromosomal Evolution in Lower Vertebrates: Sex Chromosomes in Neotropical Fishes

    Czech Academy of Sciences Publication Activity Database

    Cioffi, M. de B.; Yano, C. F.; Sember, Alexandr; Bertollo, L.A.C.

    2017-01-01

    Roč. 8, č. 10 (2017), č. článku 258. ISSN 2073-4425 R&D Projects: GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : alternative evolutionary models * simple and multiple sex chromosomes * independent and common origins Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 3.600, year: 2016

  5. Psychoeducational Implications of Sex Chromosome Anomalies

    Science.gov (United States)

    Wodrich, David L.; Tarbox, Jennifer

    2008-01-01

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

  6. [Sex-linked juvenile retinoschisis].

    Science.gov (United States)

    François, P; Turut, P; Soltysik, C; Hache, J C

    1976-02-01

    About 13 observations of sexe linked juvenile retinoschisis, the authors describe the ophthalmoscopic, fluorographic and functional aspects of the disease whose caracteristics are:--its sexe linked recessive heredity; --its clinical characterestics associating: a microcystic macular degeneration, peripheral retinal lesions, vitreous body alterations, --an electroretinogram of the negative type.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-09-01

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

  8. New insights into sex chromosome evolution in anole lizards (Reptilia, Dactyloidae).

    Science.gov (United States)

    Giovannotti, M; Trifonov, V A; Paoletti, A; Kichigin, I G; O'Brien, P C M; Kasai, F; Giovagnoli, G; Ng, B L; Ruggeri, P; Cerioni, P Nisi; Splendiani, A; Pereira, J C; Olmo, E; Rens, W; Caputo Barucchi, V; Ferguson-Smith, M A

    2017-03-01

    Anoles are a clade of iguanian lizards that underwent an extensive radiation between 125 and 65 million years ago. Their karyotypes show wide variation in diploid number spanning from 26 (Anolis evermanni) to 44 (A. insolitus). This chromosomal variation involves their sex chromosomes, ranging from simple systems (XX/XY), with heterochromosomes represented by either micro- or macrochromosomes, to multiple systems (X 1 X 1 X 2 X 2 /X 1 X 2 Y). Here, for the first time, the homology relationships of sex chromosomes have been investigated in nine anole lizards at the whole chromosome level. Cross-species chromosome painting using sex chromosome paints from A. carolinensis, Ctenonotus pogus and Norops sagrei and gene mapping of X-linked genes demonstrated that the anole ancestral sex chromosome system constituted by microchromosomes is retained in all the species with the ancestral karyotype (2n = 36, 12 macro- and 24 microchromosomes). On the contrary, species with a derived karyotype, namely those belonging to genera Ctenonotus and Norops, show a series of rearrangements (fusions/fissions) involving autosomes/microchromosomes that led to the formation of their current sex chromosome systems. These results demonstrate that different autosomes were involved in translocations with sex chromosomes in closely related lineages of anole lizards and that several sequential microautosome/sex chromosome fusions lead to a remarkable increase in size of Norops sagrei sex chromosomes.

  9. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Science.gov (United States)

    Gleeson, Dianne; Georges, Arthur

    2018-01-01

    Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD) and temperature-dependent sex determination (TSD) within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata) which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways. PMID:29751579

  10. Did Lizards Follow Unique Pathways in Sex Chromosome Evolution?

    Directory of Open Access Journals (Sweden)

    Shayer Mahmood Ibney Alam

    2018-05-01

    Full Text Available Reptiles show remarkable diversity in modes of reproduction and sex determination, including high variation in the morphology of sex chromosomes, ranging from homomorphic to highly heteromorphic. Additionally, the co-existence of genotypic sex determination (GSD and temperature-dependent sex determination (TSD within and among sister clades makes this group an attractive model to study and understand the evolution of sex chromosomes. This is particularly so with Lizards (Order Squamata which, among reptiles, show extraordinary morphological diversity. They also show no particular pattern of sex chromosome degeneration of the kind observed in mammals, birds and or even in snakes. We therefore speculate that sex determination sensu sex chromosome evolution is labile and rapid and largely follows independent trajectories within lizards. Here, we review the current knowledge on the evolution of sex chromosomes in lizards and discuss how sex chromosome evolution within that group differs from other amniote taxa, facilitating unique evolutionary pathways.

  11. Sex-chromosome anaphase movements in crane-fly spermatocytes are coordinated: ultraviolet microbeam irradiation of one kinetochore of one sex chromosome blocks the movements of both sex chromosomes

    International Nuclear Information System (INIS)

    Swedak, J.A.M.; Forer, A.

    1987-01-01

    Sex chromosomes in crane-fly spermatocytes move polewards at anaphase after the autosomes have reached the poles. We irradiated one kinetochore of one sex chromosome using an ultraviolet microbeam. When both sex chromosomes were normally oriented, irradiation of a single kinetochore permanently blocked movement of both sex chromosomes. Irradiation of non-kinetochore chromosomal regions or of spindle fibres did not block movement, or blocked movement only temporarily. We argue that ultraviolet irradiation of one kinetochore blocks movement of both sex chromosomes because of effects on a 'signal' system. Irradiation of one kinetochore of a maloriented sex chromosome did not block motion of either sex chromosome. However, irradiation of one kinetochore of a normally oriented sex chromosome permanently blocked motion of both that sex chromosome and the maloriented sex chromosome. Thus for the signal system to allow the sex chromosomes to move to the pole each sex chromosome must have one spindle fibre to each pole. (author)

  12. Heteromorphic Sex Chromosomes: Navigating Meiosis without a Homologous Partner

    OpenAIRE

    Checchi, Paula M.; Engebrecht, JoAnne

    2011-01-01

    Accurate chromosome segregation during meiosis relies on homology between the maternal and paternal chromosomes. Yet by definition, sex chromosomes of the heterogametic sex lack a homologous partner. Recent studies in a number of systems have shed light on the unique meiotic behavior of heteromorphic sex chromosomes, and highlight both the commonalities and differences in divergent species. During meiotic prophase, the homology-dependent processes of pairing, synapsis, and recombination have ...

  13. Sex Chromosome Translocations in the Evolution of Reproductive Isolation

    Science.gov (United States)

    Tracey, Martin L.

    1972-01-01

    Haldane's rule states that in organisms with differentiated sex chromosomes, hybrid sterility or inviability is generally expressed more frequently in the heterogametic sex. This observation has been variously explained as due to either genic or chromosomal imbalance. The fixation probabilities and mean times to fixation of sex-chromosome translocations of the type necessary to explain Haldane's rule on the basis of chromosomal imbalance have been estimated in small populations of Drosophila melanogaster. The fixation probability of an X chromosome carrying the long arm of the Y(X·YL) is approximately 30% greater than expected under the assumption of no selection. No fitness differences associated with the attached YL segment were detected. The fixation probability of a deficient Y chromosome is 300% greater than expected when the X chromosome contains the deleted portion of the Y. It is suggested that sex-chromosome translocations may play a role in the establishment of reproductive isolation. PMID:4630586

  14. Autosomal origin of sex chromosome in a polyploid plant

    Science.gov (United States)

    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,...

  15. Evolution of heteromorphic sex chromosomes in the order Aulopiformes.

    Science.gov (United States)

    Ota, K; Kobayashi, T; Ueno, K; Gojobori, T

    2000-12-23

    The fish order Aulopiformes contains both synchronously hermaphroditic and gonochoristic species. From the cytogenetic viewpoint, few reports show that gonochoristic Aulopiformes have heteromorphic sex chromosomes. Because fish in this order give us a unique opportunity to elucidate the evolution of sex chromosomes, it is important to examine a phylogenetic relationship in Aulopiformes by both molecular evolutionary and cytogenetic methods. Thus, we conducted molecular phylogenetic and cytogenetic studies of six Aulopiform species. Our results suggested that hermaphroditic species were evolutionarily derived from gonochoristic species. It follows that the hermaphroditic species might have lost the heteromorphic sex chromosomes during evolution. Here, we suggest a possibility that heteromorphic sex chromosomes can disappear from the genome, even if they have appeared once in evolution. Taking into account Ohno's hypothesis that heteromorphic sex chromosomes might have emerged from autosomes, we propose the hypothesis that heteromorphic sex chromosomes may have undergone repeated events of appearance and disappearance during the course of fish evolution.

  16. Sexually antagonistic "zygotic drive" of the sex chromosomes.

    Directory of Open Access Journals (Sweden)

    William R Rice

    2008-12-01

    Full Text Available 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 because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic "zygotic drive", because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans.

  17. Conserved sex chromosomes across adaptively radiated Anolis lizards.

    Science.gov (United States)

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

    2014-07-01

    Vertebrates possess diverse sex-determining systems, which differ in evolutionary stability among particular groups. It has been suggested that poikilotherms possess more frequent turnovers of sex chromosomes than homoiotherms, whose effective thermoregulation can prevent the emergence of the sex reversals induced by environmental temperature. Squamate reptiles used to be regarded as a group with an extensive variability in sex determination; however, we document how the rather old radiation of lizards from the genus Anolis, known for exceptional ecomorphological variability, was connected with stability in sex chromosomes. We found that 18 tested species, representing most of the phylogenetic diversity of the genus, share the gene content of their X chromosomes. Furthermore, we discovered homologous sex chromosomes in species of two genera (Sceloporus and Petrosaurus) from the family Phrynosomatidae, serving here as an outgroup to Anolis. We can conclude that the origin of sex chromosomes within iguanas largely predates the Anolis radiation and that the sex chromosomes of iguanas remained conserved for a significant part of their evolutionary history. Next to therian mammals and birds, Anolis lizards therefore represent another adaptively radiated amniote clade with conserved sex chromosomes. We argue that the evolutionary stability of sex-determining systems may reflect an advanced stage of differentiation of sex chromosomes rather than thermoregulation strategy. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  18. High degree of sex chromosome differentiation in stickleback fishes

    Directory of Open Access Journals (Sweden)

    Shimada Yukinori

    2011-09-01

    Full Text Available Abstract 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.

  19. Sex chromosome repeats tip the balance towards speciation.

    Science.gov (United States)

    O'Neill, Michael J; O'Neill, Rachel J

    2018-04-06

    Because sex chromosomes, by definition, carry genes that determine sex, mutations that alter their structural and functional stability can have immediate consequences for the individual by reducing fertility, but also for a species by altering the sex ratio. Moreover, the sex-specific segregation patterns of heteromorphic sex chromosomes make them havens for selfish genetic elements that not only create sub-optimal sex ratios, but can also foster sexual antagonism. Compensatory mutations to mitigate antagonism or return sex ratios to a Fisherian optimum can create hybrid incompatibility and establish reproductive barriers leading to species divergence. The destabilizing influence of these selfish elements is often manifest within populations as copy number variants (CNVs) in satellite repeats and transposable elements (TE) or as CNVs involving sex determining genes, or genes essential to fertility and sex chromosome dosage compensation. This review catalogs several examples of well-studied sex chromosome CNVs in Drosophilids and mammals that underlie instances of meiotic drive, hybrid incompatibility and disruptions to sex differentiation and sex chromosome dosage compensation. While it is difficult to pinpoint a direct cause/effect relationship between these sex chromosome CNVs and speciation, it is easy to see how their effects in creating imbalances between the sexes, and the compensatory mutations to restore balance, can lead to lineage splitting and species formation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Nonequilibrium Chromosome Looping via Molecular Slip Links

    Science.gov (United States)

    Brackley, C. A.; Johnson, J.; Michieletto, D.; Morozov, A. N.; Nicodemi, M.; Cook, P. R.; Marenduzzo, D.

    2017-09-01

    We propose a model for the formation of chromatin loops based on the diffusive sliding of molecular slip links. These mimic the behavior of molecules like cohesin, which, along with the CTCF protein, stabilize loops which contribute to organizing the genome. By combining 3D Brownian dynamics simulations and 1D exactly solvable nonequilibrium models, we show that diffusive sliding is sufficient to account for the strong bias in favor of convergent CTCF-mediated chromosome loops observed experimentally. We also find that the diffusive motion of multiple slip links along chromatin is rectified by an intriguing ratchet effect that arises if slip links bind to the chromatin at a preferred "loading site." This emergent collective behavior favors the extrusion of loops which are much larger than the ones formed by single slip links.

  1. Aplastic Anemia in Two Patients with Sex Chromosome Aneuploidies.

    Science.gov (United States)

    Rush, Eric T; Schaefer, G Bradley; Sanger, Warren G; Coccia, Peter F

    2015-01-01

    Sex chromosome aneuploidies range in incidence from rather common to exceedingly rare and have a variable phenotype. We report 2 patients with sex chromosome aneuploidies who developed severe aplastic anemia requiring treatment. The first patient had tetrasomy X (48,XXXX) and presented at 9 years of age, and the second patient had trisomy X (47,XXX) and presented at 5 years of age. Although aplastic anemia has been associated with other chromosomal abnormalities, sex chromosome abnormalities have not been traditionally considered a risk factor for this condition. A review of the literature reveals that at least one other patient with a sex chromosome aneuploidy (45,X) has suffered from aplastic anemia and that other autosomal chromosomal anomalies have been described. Despite the uncommon nature of each condition, it is possible that the apparent association is coincidental. A better understanding of the genetic causes of aplastic anemia remains important. © 2015 S. Karger AG, Basel.

  2. Allele-specific marker generation and linkage mapping on the Xiphophorus sex chromosomes.

    Science.gov (United States)

    Woolcock, B; Kazianis, S; Lucito, R; Walter, R B; Kallman, K D; Morizot, D C; Vielkind, J R

    2006-01-01

    There is great interest in the sex chromosomes of Xiphophorus fishes because both WY/YY and XX/XY sex-determining mechanisms function in these species, with at least one taxon possessing all three types of sex chromosomes, and because in certain interspecific hybrids melanoma arises as a consequence of inheritance of the sex-linked macromelanophore determining locus (MDL). Representational difference analysis (RDA) has been used to clone two sequences from the sex-determining region of X. maculatus, including a cholinergic receptor, nicotinic, delta polypeptide (CHRND) orthologue. Allele-specific assays for these sequences, as well as for the sex-linked XMRK1 and XMRK2 genes, were developed to distinguish W, X, and Y chromosomes derived from a X. maculatus (XX/XY) strain and a X. helleri (WY/YY) strain. Linkage mapping localized these markers to linkage group (LG) 24. No recombinants were observed between XMRK2 and MDL, confirming a role for XMRK2 in macromelanophore development. Although the master sex-determining (SD) locus certainly resides on Xiphophorus LG 24, autosomal loci are probably involved in sex determination as well, as indicated by the abnormal sex ratios in the backcross hybrids that contrast theoretical predictions based on LG 24 genotyping. Marker development and allelic discrimination on the Xiphophorus sex chromosomes should prove highly useful for studies that utilize this genus as an animal model.

  3. Untangling the Contributions of Sex-Specific Gene Regulation and X-Chromosome Dosage to Sex-Biased Gene Expression in Caenorhabditis elegans

    Science.gov (United States)

    Kramer, Maxwell; Rao, Prashant; Ercan, Sevinc

    2016-01-01

    Dosage compensation mechanisms equalize the level of X chromosome expression between sexes. Yet the X chromosome is often enriched for genes exhibiting sex-biased, i.e., imbalanced expression. The relationship between X chromosome dosage compensation and sex-biased gene expression remains largely unexplored. Most studies determine sex-biased gene expression without distinguishing between contributions from X chromosome copy number (dose) and the animal’s sex. Here, we uncoupled X chromosome dose from sex-specific gene regulation in Caenorhabditis elegans to determine the effect of each on X expression. In early embryogenesis, when dosage compensation is not yet fully active, X chromosome dose drives the hermaphrodite-biased expression of many X-linked genes, including several genes that were shown to be responsible for hermaphrodite fate. A similar effect is seen in the C. elegans germline, where X chromosome dose contributes to higher hermaphrodite X expression, suggesting that lack of dosage compensation in the germline may have a role in supporting higher expression of X chromosomal genes with female-biased functions in the gonad. In the soma, dosage compensation effectively balances X expression between the sexes. As a result, somatic sex-biased expression is almost entirely due to sex-specific gene regulation. These results suggest that lack of dosage compensation in different tissues and developmental stages allow X chromosome copy number to contribute to sex-biased gene expression and function. PMID:27356611

  4. The XX sex chromosome complement in mice is associated with increased spontaneous lupus compared with XY.

    Science.gov (United States)

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

    2012-08-01

    Many autoimmune diseases are characterised by a female predominance. This may be caused by sex hormones, sex chromosomes or both. This report uses a transgenic mouse model to investigate how sex chromosome complement, not confounded by differences in gonadal type, might contribute to lupus pathogenesis. Transgenic NZM2328 mice were created by deletion of the Sry gene from the Y chromosome, thereby separating genetic from gonadal sex. Survival, renal histopathology and markers of immune activation were compared in mice carrying the XX versus the XY(-) sex chromosome complement, with each genotype being ovary bearing. Mice with XX sex chromosome complement compared with XY(-) exhibited poorer survival rates and increased kidney pathology. Splenic T lymphocytes from XX mice demonstrated upregulated X-linked CD40 ligand expression and higher levels of activation markers ex vivo. Increased MMP, TGF and IL-13 production was found, while IL-2 was lower in XX mice. An accumulation of splenic follicular B cells and peritoneal marginal zone B cells was observed, coupled with upregulated costimulatory marker expression on B cells in XX mice. These data show that the XX sex chromosome complement, compared with XY(-), is associated with accelerated spontaneous lupus.

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

    Science.gov (United States)

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

    2003-03-01

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

  6. Evolution of vertebrate sex chromosomes and dosage compensation.

    Science.gov (United States)

    Graves, Jennifer A Marshall

    2016-01-01

    Differentiated sex chromosomes in mammals and other vertebrates evolved independently but in strikingly similar ways. Vertebrates with differentiated sex chromosomes share the problems of the unequal expression of the genes borne on sex chromosomes, both between the sexes and with respect to autosomes. Dosage compensation of genes on sex chromosomes is surprisingly variable - and can even be absent - in different vertebrate groups. Systems that compensate for different gene dosages include a wide range of global, regional and gene-by-gene processes that differ in their extent and their molecular mechanisms. However, many elements of these control systems are similar across distant phylogenetic divisions and show parallels to other gene silencing systems. These dosage systems cannot be identical by descent but were probably constructed from elements of ancient silencing mechanisms that are ubiquitous among vertebrates and shared throughout eukaryotes.

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

    Science.gov (United States)

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

    2014-03-01

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

  8. Turnover of sex chromosomes induced by sexual conflict

    NARCIS (Netherlands)

    van Doorn, G. S.; Kirkpatrick, Mark

    2007-01-01

    Sex-determination genes are among the most fluid features of the genome in many groups of animals(1,2). In some taxa the master sex-determining gene moves frequently between chromosomes, whereas in other taxa different genes have been recruited to determine the sex of the zygotes. There is a well

  9. Convergent evolution of chromosomal sex-determining regions in the animal and fungal kingdoms.

    Directory of Open Access Journals (Sweden)

    James A Fraser

    2004-12-01

    Full Text Available Sexual identity is governed by sex chromosomes in plants and animals, and by mating type (MAT loci in fungi. Comparative analysis of the MAT locus from a species cluster of the human fungal pathogen Cryptococcus revealed sequential evolutionary events that fashioned this large, highly unusual region. We hypothesize that MAT evolved via four main steps, beginning with acquisition of genes into two unlinked sex-determining regions, forming independent gene clusters that then fused via chromosomal translocation. A transitional tripolar intermediate state then converted to a bipolar system via gene conversion or recombination between the linked and unlinked sex-determining regions. MAT was subsequently subjected to intra- and interallelic gene conversion and inversions that suppress recombination. These events resemble those that shaped mammalian sex chromosomes, illustrating convergent evolution in sex-determining structures in the animal and fungal kingdoms.

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

    Directory of Open Access Journals (Sweden)

    Zhou Qi

    2012-03-01

    Full Text Available Abstract Background Drosophila albomicans is a unique model organism for studying both sex chromosome and B chromosome evolution. A pair of its autosomes comprising roughly 40% of the whole genome has fused to the ancient X and Y chromosomes only about 0.12 million years ago, thereby creating the youngest and most gene-rich neo-sex system reported to date. This species also possesses recently derived B chromosomes that show non-Mendelian inheritance and significantly influence fertility. Methods We sequenced male flies with B chromosomes at 124.5-fold genome coverage using next-generation sequencing. To characterize neo-Y specific changes and B chromosome sequences, we also sequenced inbred female flies derived from the same strain but without B's at 28.5-fold. Results We assembled a female genome and placed 53% of the sequence and 85% of the annotated proteins into specific chromosomes, by comparison with the 12 Drosophila genomes. Despite its very recent origin, the non-recombining neo-Y chromosome shows various signs of degeneration, including a significant enrichment of non-functional genes compared to the neo-X, and an excess of tandem duplications relative to other chromosomes. We also characterized a B-chromosome linked scaffold that contains an actively transcribed unit and shows sequence similarity to the subcentromeric regions of both the ancient X and the neo-X chromosome. Conclusions Our results provide novel insights into the very early stages of sex chromosome evolution and B chromosome origination, and suggest an unprecedented connection between the births of these two systems in D. albomicans.

  11. Chromosome Banding in Amphibia. XXXVI. Multimorphic Sex Chromosomes and an Enigmatic Sex Determination in Eleutherodactylus johnstonei (Anura, Eleutherodactylidae).

    Science.gov (United States)

    Schmid, Michael; Steinlein, Claus

    2018-01-01

    A detailed cytogenetic study on the leaf litter frog Eleutherodactylus johnstonei from 14 different Caribbean islands and the mainlands of Venezuela and Guyana revealed the existence of multimorphic XY♂/XX♀ sex chromosomes 14. Their male sex determination and development depends either on the presence of 2 telocentric chromosomes 14 (XtYt), or on 1 submetacentric chromosome 14 (Xsm) plus 1 telocentric chromosome 14 (Yt), or on the presence of 2 submetacentric chromosomes 14 (XsmYsm). The female sex determination and development requires either the presence of 2 telocentric chromosomes 14 (XtXt) or 2 submetacentric chromosomes 14 (XsmXsm). In all individuals analyzed, the sex chromosomes 14 carry a prominent nucleolus organizer region in their long arms. An explanation is given for the origin of the (XtYt)♂, (XsmYt)♂, (XsmYsm)♂, (XtXt)♀, and (XsmXsm)♀ in the different populations of E. johnstonei. Furthermore, the present study gives detailed data on the chromosome banding patterns, in situ hybridization experiments, and the genome size of E. johnstonei. © 2018 S. Karger AG, Basel.

  12. Structural, functional, and evolutionary features of plant sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Vyskot, Boris; Hobza, Roman; Kejnovský, Eduard; Žlůvová, Jitka; Janoušek, Bohuslav

    2009-01-01

    Roč. 17, č. 4 (2009), s. 547 ISSN 0967-3849. [17th International Chromosome Conference. 23.06.2009-26.06.2009, Boone] R&D Projects: GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : sex chromosomes * Silene latifolia * epigenetic Subject RIV: BO - Biophysics

  13. Psychotic disorder and its characteristics in sex chromosome aneuploidies

    Directory of Open Access Journals (Sweden)

    Annapia Verri

    2009-09-01

    Full Text Available Sex chromosome anomalies have been associated with psychoses. We report a patient with XYY chromosome anomaly who developed a paranoid psychosis. The second case deal with a 51-year-old woman affected by Turner Syndrome and Psychotic Disorder, with a prevalent somatic and sexual focus.

  14. ON THE TOPOGRAPHY OF THE SEX- CHROMOSOME IN

    Indian Academy of Sciences (India)

    over, we endeavoured to find the relative distribution of these genes in their chromosome, and to determine the distance between them, having in view the construction of a map of the sex-chromosome of fowls. We studied the following genes (in ...

  15. Association testing to detect gene-gene interactions on sex chromosomes in trio data

    Directory of Open Access Journals (Sweden)

    Yeonok eLee

    2013-11-01

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

  16. [Identification of the genetic sex chromosomes in the monogenic blowfly Chrysomya rufifacies (Calliphoridae, Diptera)].

    Science.gov (United States)

    Ullerich, F H

    1975-01-01

    Previous investigations have shown the sex determination in the monogenic blowfly Chrysomya rufifacies to be controlled by a cytologically not discernible homogametry-heterogamety mechanism in the female. Female-producing (thelygenic) females are assumed to be heterozygous for a dominant female sex realizer (F') with sex-predetermining properties, while male-producing (arrhenogenic) females as well as males are supposed to be homozygous for the recessive allele (f). In order to identify the genetic sex chromosomes of C. rufifacies among its five pairs of long euchromatic chromosomes (nos. 1-5) plus one pair of small heterochromatic ones (no. 6), all chromosomes were marked by reciprocal translocations induced by X-ray treatment of adult males. The inheritance of thirteen different heteroxygous translocations has been analyzed. All of the translocations (eleven) between two of the four longer chromosomes did not show sex-linked inheritance, thus demonstrating the autosomal character of the chromosomes nos 1, 2, 3 and 4. The same is true for the translocation T6 (2/6). Therefore the small heterochromatic chromosome no. 6, corresponding to the morphlogically differentiated six chromosomes within the amphogenic calliphorid species, remains without sex determining function in the monogenic fly. This could be confirmed by the analysis of monosomic (monosomy-6) and trisomic (trisomy-6) individuals, which resulted from meiotic non-disfunction in T6/+ translocation heterozygotes. Contrary to these translocations, the heteroxygous 5/2 translocation (T14) exhibited sex-linked inheritance: There was but a very low frequency (0,76 per cent) of recombinants resulting from crossing-over between F'/f and the translocation breakage point in theylgenic F1 T14/+females. The sex-linked inheritance of T14 was confirmed by the progeny of a thelygenic F1 T14/+ female crossed to a homozygous T14/T14 translocation male.Among the offspring of that F1 T14/+ female, which had received the

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

    Science.gov (United States)

    Immler, Simone; Otto, Sarah Perin

    2015-03-01

    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. © 2015 The Author(s).

  18. Genetic markers, translocations and sexing genes on chromosome 2 of Ceratitis capitata

    International Nuclear Information System (INIS)

    Cladera, J.L.

    1997-01-01

    A review is presented of results obtained in a search for genetic markers, translocations and selectable genes obtained at the Instituto de Genetica, Castelar, Argentina, with special reference to chromosome 2 linked mutations and genes useful for developing self-sexing strains in Ceratitis capitata. (author)

  19. Effect of gamma irradiation on sex chromatin body appearance and the sex chromosome aberrations in the potato tuber moth, phthorimaea operculella (Lepidoptera: Gelechiidae)

    International Nuclear Information System (INIS)

    Makee, H.

    2007-01-01

    Genetic sexing technique based on the construction of a Balanced Lethal Strain (BLS) has been proposed for Phthorimaea operculella (Zeller). The isolation of female with T(W. Z) translocation is a fundamental step to develop such strain. Gamma irradiation was used to induce the requested translocations. The availability of sex-linked morphological marker is required to facilitate the detection of such mutations. Since a visible sex-linked marker has not been found in P. operculella, therefore main aim of our study was to determine the possibility of using sex heterochromatin body as a marker to identify the required translocated females. The appearance of sex heterochromatin body and the analysis of sex chromosomes in F1 females of irradiated P. operculella females were investigated. The percentage of abnormality in sex heterochromatin body in highly polyploid Malpighian tubule nuclei was increased by increasing the applied dose. Based on the appearance of this body, 3 mutant lines were isolated: elongated, small, fragmented lines. W chromosome was easily distinguished from Z chromosome when the analysis of pachytene sex chromosome bivalents of P. operculella females was carried out. The aberrations involved W chromosome directly influenced the appearance of sex heterochromatin body in highly polyploid somatic cells of the isolated mutant lines. The results showed that sex heterochromatin could be used as sex determination and cytogenetic marker in P. operculella. (Author)

  20. Effect of gamma irradiation on sex chromatin body appearance and the sex chromosome aberrations in the potato tuber moth, phthorimaea operculella (Lepidoptera: Gelechiidae)

    International Nuclear Information System (INIS)

    Makee, H.

    2006-05-01

    Genetic sexing technique based on the construction of a Balanced Lethal Strain (BLS) has been proposed for Phthorimaea operculella (Zeller). The isolation of female with T(W; Z) translocation is a fundamental step to develop such strain. Gamma irradiation was used to induce the requested translocations. The availability of sex-linked morphological marker is required to facilitate the detection of such mutations. Since a visible sex-linked marker has not been found in P. operculella, therefore main aim of our study was to determine the possibility of using sex heterochromatin body as a marker to identify the required translocated females. The appearance of sex heterochromatin body and the analysis of sex chromosomes in F1 females of irradiated P. operculella females were investigated. The percentage of abnormality in sex heterochromatin body in highly polyploid Malpighian tubule nuclei was increased by increasing the applied dose. Based on the appearance of this body, 3 mutant lines were isolated: elongated, small, fragmented lines. W chromosome was easily distinguished from Z chromosome when the analysis of pachytene sex chromosome bivalents of P. operculella females was carried out. The aberrations involved W chromosome directly influenced the appearance of sex heterochromatin body in highly polyploid somatic cells of the isolated mutant lines. The results showed that sex heterochromatin could be used as sex determination and cytogenetic marker in P. operculella. (Author)

  1. Sex chromosomes and speciation in birds and other ZW systems.

    Science.gov (United States)

    Irwin, Darren E

    2018-02-14

    Theory and empirical patterns suggest a disproportionate role for sex chromosomes in evolution and speciation. Focusing on ZW sex determination (females ZW, males ZZ; the system in birds, many snakes, and lepidopterans), I review how evolutionary dynamics are expected to differ between the Z, W and the autosomes, discuss how these differences may lead to a greater role of the sex chromosomes in speciation and use data from birds to compare relative evolutionary rates of sex chromosomes and autosomes. Neutral mutations, partially or completely recessive beneficial mutations, and deleterious mutations under many conditions are expected to accumulate faster on the Z than on autosomes. Sexually antagonistic polymorphisms are expected to arise on the Z, raising the possibility of the spread of preference alleles. The faster accumulation of many types of mutations and the potential for complex evolutionary dynamics of sexually antagonistic traits and preferences contribute to a role for the Z chromosome in speciation. A quantitative comparison among a wide variety of bird species shows that the Z tends to have less within-population diversity and greater between-species differentiation than the autosomes, likely due to both adaptive evolution and a greater rate of fixation of deleterious alleles. The W chromosome also shows strong potential to be involved in speciation, in part because of its co-inheritance with the mitochondrial genome. While theory and empirical evidence suggest a disproportionate role for sex chromosomes in speciation, the importance of sex chromosomes is moderated by their small size compared to the whole genome. © 2018 John Wiley & Sons Ltd.

  2. The genomics of plant sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Vyskot, Boris; Hobza, Roman

    2015-01-01

    Roč. 236, JUL 2015 (2015), s. 126-135 ISSN 0168-9452 R&D Projects: GA ČR(CZ) GBP501/12/G090; GA ČR(CZ) GAP501/12/2220 Institutional support: RVO:68081707 Keywords : Y-CHROMOSOME * SILENE-LATIFOLIA * DIOECIOUS PLANT Subject RIV: BO - Biophysics Impact factor: 3.362, year: 2015

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

    Czech Academy of Sciences Publication Activity Database

    Hobza, Roman; Kejnovský, Eduard; Vyskot, Boris; Widmer, A.

    2007-01-01

    Roč. 278, č. 6 (2007), s. 633-638 ISSN 1617-4615 R&D Projects: GA ČR(CZ) GA204/05/2097; GA ČR(CZ) GA521/06/0056 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : chromosomal rearrangements * sex chromosomes * FISH Subject RIV: BO - Biophysics Impact factor: 2.978, year: 2007

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

    Directory of Open Access Journals (Sweden)

    Fumihiko eMaekawa

    2014-08-01

    Full Text Available 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.

  5. Establishment of a 10-Plex Quantitative Fluorescent-PCR Assay for rapid diagnosis of sex chromosome aneuploidies.

    Directory of Open Access Journals (Sweden)

    Xingmei Xie

    Full Text Available 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.

  6. Y Fuse? Sex Chromosome Fusions in Fishes and Reptiles

    Science.gov (United States)

    Vamosi, Jana C.; Peichel, Catherine L.; Valenzuela, Nicole; Kitano, Jun

    2015-01-01

    Chromosomal fusion plays a recurring role in the evolution of adaptations and reproductive isolation among species, yet little is known of the evolutionary drivers of chromosomal fusions. Because sex chromosomes (X and Y in male heterogametic systems, Z and W in female heterogametic systems) differ in their selective, mutational, and demographic environments, those differences provide a unique opportunity to dissect the evolutionary forces that drive chromosomal fusions. We estimate the rate at which fusions between sex chromosomes and autosomes become established across the phylogenies of both fishes and squamate reptiles. Both the incidence among extant species and the establishment rate of Y-autosome fusions is much higher than for X-autosome, Z-autosome, or W-autosome fusions. Using population genetic models, we show that this pattern cannot be reconciled with many standard explanations for the spread of fusions. In particular, direct selection acting on fusions or sexually antagonistic selection cannot, on their own, account for the predominance of Y-autosome fusions. The most plausible explanation for the observed data seems to be (a) that fusions are slightly deleterious, and (b) that the mutation rate is male-biased or the reproductive sex ratio is female-biased. We identify other combinations of evolutionary forces that might in principle account for the data although they appear less likely. Our results shed light on the processes that drive structural changes throughout the genome. PMID:25993542

  7. Sex chromosome diversity in Armenian toad grasshoppers (Orthoptera, Acridoidea, Pamphagidae)

    Science.gov (United States)

    Bugrov, Alexander G.; Jetybayev, Ilyas E.; Karagyan, Gayane H.; Rubtsov, Nicolay B.

    2016-01-01

    Abstract Although previous cytogenetic analysis of Pamphagidae grasshoppers pointed to considerable karyotype uniformity among most of the species in the family, our study of species from Armenia has discovered other, previously unknown karyotypes, differing from the standard for Pamphagidae mainly in having unusual sets of sex chromosomes. Asiotmethis turritus (Fischer von Waldheim, 1833), Paranocaracris rubripes (Fischer von Waldheim, 1846), and Nocaracris cyanipes (Fischer von Waldheim, 1846) were found to have the karyotype 2n♂=16+neo-XY and 2n♀=16+neo-XX, the neo-X chromosome being the result of centromeric fusion of an ancient acrocentric X chromosome and a large acrocentric autosome. The karyotype of Paranothrotes opacus (Brunner von Wattenwyl, 1882) was found to be 2n♂=14+X1X2Y and 2n♀=14+X1X1X2X2., the result of an additional chromosome rearrangement involving translocation of the neo-Y and another large autosome. Furthermore, evolution of the sex chromosomes in these species has involved different variants of heterochromatinization and miniaturization of the neo-Y. The karyotype of Eremopeza festiva (Saussure, 1884), in turn, appeared to have the standard sex determination system described earlier for Pamphagidae grasshoppers, 2n♂=18+X0 and 2n♀=18+XX, but all the chromosomes of this species were found to have small second C-positive arms. Using fluorescent in situ hybridization (FISH) with 18S rDNA and telomeric (TTAGG)n DNA repeats to yield new data on the structural organization of chromosomes in the species studied, we found that for most of them, clusters of repeats homologous to 18S rDNA localize on two, three or four pairs of autosomes and on the X. In Eremopeza festiva, however, FISH with labelled 18S rDNA painted C-positive regions of all autosomes and the X chromosome; clusters of telomeric repeats localized primarily on the ends of the chromosome arms. Overall, we conclude that the different stages of neo-Y degradation revealed in

  8. Complex evolutionary trajectories of sex chromosomes across bird taxa

    DEFF Research Database (Denmark)

    Zhou, Qi; Zhang, Jilin; Bachtrog, Doris

    2014-01-01

    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...

  9. Gender in plants: sex chromosomes are emerging from the fog

    Czech Academy of Sciences Publication Activity Database

    Vyskot, Boris; Hobza, Roman

    2004-01-01

    Roč. 20, č. 9 (2004), s. 432-438 ISSN 0168-9525 R&D Projects: GA AV ČR(CZ) KSK5052113 Keywords : sex chromosomes * dioecious papaya * evolution Subject RIV: BO - Biophysics Impact factor: 14.643, year: 2004

  10. Genetics of dioecy and causal sex chromosomes in plants

    Indian Academy of Sciences (India)

    2014-04-15

    chromosome evolution; sex-ratio variation ...... interaction between the two genes, Cm ACS7 and Cm W1P1, ... son of low pollinator density seed formation will be scanty ...... Kaltz O. and Bell G. 2002 The ecology and genetics of fitness in.

  11. Neurogenin 3 Mediates Sex Chromosome Effects on the Generation of Sex Differences in Hypothalamic Neuronal Development

    Directory of Open Access Journals (Sweden)

    Maria Julia Scerbo

    2014-07-01

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

  12. Sex-chromosome differentiation parallels postglacial range expansion in European tree frogs (Hyla arborea).

    Science.gov (United States)

    Dufresnes, Christophe; Bertholet, Youna; Wassef, Jérôme; Ghali, Karim; Savary, Romain; Pasteur, Baptiste; Brelsford, Alan; Rozenblut-Kościsty, Beata; Ogielska, Maria; Stöck, Matthias; Perrin, Nicolas

    2014-12-01

    Occasional XY recombination is a proposed explanation for the sex-chromosome homomorphy in European tree frogs. Numerous laboratory crosses, however, failed to detect any event of male recombination, and a detailed survey of NW-European Hyla arborea populations identified male-specific alleles at sex-linked loci, pointing to the absence of XY recombination in their recent history. Here, we address this paradox in a phylogeographic framework by genotyping sex-linked microsatellite markers in populations and sibships from the entire species range. Contrasting with postglacial populations of NW Europe, which display complete absence of XY recombination and strong sex-chromosome differentiation, refugial populations of the southern Balkans and Adriatic coast show limited XY recombination and large overlaps in allele frequencies. Geographically and historically intermediate populations of the Pannonian Basin show intermediate patterns of XY differentiation. Even in populations where X and Y occasionally recombine, the genetic diversity of Y haplotypes is reduced below the levels expected from the fourfold drop in copy numbers. This study is the first in which X and Y haplotypes could be phased over the distribution range in a species with homomorphic sex chromosomes; it shows that XY-recombination patterns may differ strikingly between conspecific populations, and that recombination arrest may evolve rapidly (<5000 generations). © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  13. Identifying new sex-linked genes through BAC sequencing in the dioecious plant Silene latifolia

    Czech Academy of Sciences Publication Activity Database

    Blavet, Nicolas; Blavet, Hana; Muyle, A.; Käfer, J.; Cegan, R.; Deschamps, C.; Zemp, N.; Mousset, S.; Aubourg, S.; Bergero, R.; Charlesworth, D.; Hobza, Roman; Widmer, A.; Marais, G.A.B.

    2015-01-01

    Roč. 16, JUL 25 (2015), s. 546 ISSN 1471-2164 R&D Projects: GA ČR GAP501/12/2220 Institutional support: RVO:61389030 Keywords : Sex chromosomes * Sex-linked genes * Plant Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.867, year: 2015

  14. Female heterogamety in Madagascar chameleons (Squamata: Chamaeleonidae: Furcifer): differentiation of sex and neo-sex chromosomes

    Science.gov (United States)

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

    2015-01-01

    Amniotes possess variability in sex determining mechanisms, however, this diversity is still only partially known throughout the clade and sex determining systems still remain unknown even in such a popular and distinctive lineage as chameleons (Squamata: Acrodonta: Chamaeleonidae). Here, we present evidence for female heterogamety in this group. The Malagasy giant chameleon (Furcifer oustaleti) (chromosome number 2n = 22) possesses heteromorphic Z and W sex chromosomes with heterochromatic W. The panther chameleon (Furcifer pardalis) (2n = 22 in males, 21 in females), the second most popular chameleon species in the world pet trade, exhibits a rather rare Z1Z1Z2Z2/Z1Z2W system of multiple sex chromosomes, which most likely evolved from W-autosome fusion. Notably, its neo-W chromosome is partially heterochromatic and its female-specific genetic content has expanded into the previously autosomal region. Showing clear evidence for genotypic sex determination in the panther chameleon, we resolve the long-standing question of whether or not environmental sex determination exists in this species. Together with recent findings in other reptile lineages, our work demonstrates that female heterogamety is widespread among amniotes, adding another important piece to the mosaic of knowledge on sex determination in amniotes needed to understand the evolution of this important trait. PMID:26286647

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

    Science.gov (United States)

    Graves, Jennifer A Marshall

    2014-04-01

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

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

    DEFF Research Database (Denmark)

    Ottesen, Anne-Marie; Aksglaede, Lise; Garn, Inger

    2010-01-01

    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 wi......,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....

  17. An Allometric Analysis of Sex and Sex Chromosome Dosage Effects on Subcortical Anatomy in Humans

    Science.gov (United States)

    Clasen, Liv; Giedd, Jay N.; Blumenthal, Jonathan; Lerch, Jason P.; Chakravarty, M. Mallar; Raznahan, Armin

    2016-01-01

    Structural neuroimaging of humans with typical and atypical sex-chromosome complements has established the marked influence of both Yand X-/Y-chromosome dosage on total brain volume (TBV) and identified potential cortical substrates for the psychiatric phenotypes associated with sex-chromosome aneuploidy (SCA). Here, in a cohort of 354 humans with varying karyotypes (XX, XY, XXX, XXY, XYY, XXYY, XXXXY), we investigate sex and SCA effects on subcortical size and shape; focusing on the striatum, pallidum and thalamus. We find large effect-size differences in the volume and shape of all three structures as a function of sex and SCA. We correct for TBV effects with a novel allometric method harnessing normative scaling rules for subcortical size and shape in humans, which we derive here for the first time. We show that all three subcortical volumes scale sublinearly with TBV among healthy humans, mirroring known relationships between subcortical volume and TBV among species. Traditional TBV correction methods assume linear scaling and can therefore invert or exaggerate sex and SCA effects on subcortical anatomy. Allometric analysis restricts sex-differences to: (1) greater pallidal volume (PV) in males, and (2) relative caudate head expansion and ventral striatum contraction in females. Allometric analysis of SCA reveals that supernumerary X- and Y-chromosomes both cause disproportionate reductions in PV, and coordinated deformations of striatopallidal shape. Our study provides a novel understanding of sex and sex-chromosome dosage effects on subcortical organization, using an allometric approach that can be generalized to other basic and clinical structural neuroimaging settings. SIGNIFICANCE STATEMENT Sex and sex-chromosome dosage (SCD) are known to modulate human brain size and cortical anatomy, but very little is known regarding their impact on subcortical structures that work with the cortex to subserve a range of behaviors in health and disease. Moreover

  18. Isolation of a sex-linked DNA sequence in cranes.

    Science.gov (United States)

    Duan, W; Fuerst, P A

    2001-01-01

    A female-specific DNA fragment (CSL-W; crane sex-linked DNA on W chromosome) was cloned from female whooping cranes (Grus americana). From the nucleotide sequence of CSL-W, a set of polymerase chain reaction (PCR) primers was identified which amplify a 227-230 bp female-specific fragment from all existing crane species and some other noncrane species. A duplicated versions of the DNA segment, which is found to have a larger size (231-235 bp) than CSL-W in both sexes, was also identified, and was designated CSL-NW (crane sex-linked DNA on non-W chromosome). The nucleotide similarity between the sequences of CSL-W and CSL-NW from whooping cranes was 86.3%. The CSL primers do not amplify any sequence from mammalian DNA, limiting the potential for contamination from human sources. Using the CSL primers in combination with a quick DNA extraction method allows the noninvasive identification of crane gender in less than 10 h. A test of the methodology was carried out on fully developed body feathers from 18 captive cranes and resulted in 100% successful identification.

  19. Cloning an expressed gene shared by the human sex chromosomes

    International Nuclear Information System (INIS)

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

    1986-01-01

    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 λgt11 expression system in Escherichia coli and immunoscreening techniques, the authors have isolated a cDNA clone whose primary product is recognized by 12E7. Southern blot analysis using somatic cell hybrids containing only the human X or Y chromosomes shows that the sequences reacting with the cDNA clone are localized to the sex chromosomes. In addition, the clone hybridizes to DNAs isolated from mouse cells that have been transfected with human DNA and selected for 12E7 expression on the fluorescence-activated cell sorter. The authors conclude that the cDNA clone encodes the 12E7 antigen, which is the primary product of the MIC2 loci. The clone was used to explore sequence homology between MIC2X and MIC2Y; these loci are closely related, if not identical

  20. Distribution of sex chromosomes (XY) in lymphocyte metaphase spreads of dairy bulls

    OpenAIRE

    Kotikalapudi Rosaiah; Patel Rajesh Kumar; Medidi Hemanth; Sugali Nagaraju Naik

    2013-01-01

    Position of autosome and sex chromosomes in metaphase spreads is grate concerned of Cytogeneticians worldwide to understand cell biology. A few isolated studies have been conducted for the distribution of chromosomes in metaphase spread. Our studies reveal that most sex chromosomes (XY) remain on periphery and semi-periphery, 84.16% for X and 86.97% for Y respectively, in round metaphase spreads. The application of sex chromosome position in metaphase sprea...

  1. Divergent Evolutionary Trajectories of Two Young, Homomorphic, and Closely Related Sex Chromosome Systems

    Science.gov (United States)

    Furman, Benjamin L S; Evans, Ben J

    2018-01-01

    Abstract There exists extraordinary variation among species in the degree and nature of sex chromosome divergence. However, much of our knowledge about sex chromosomes is based on comparisons between deeply diverged species with different ancestral sex chromosomes, making it difficult to establish how fast and why sex chromosomes acquire variable levels of divergence. To address this problem, we studied sex chromosome evolution in two species of African clawed frog (Xenopus), both of whom acquired novel systems for sex determination from a recent common ancestor, and both of whom have female (ZW/ZZ) heterogamy. Derived sex chromosomes of one species, X. laevis, have a small region of suppressed recombination that surrounds the sex determining locus, and have remained this way for millions of years. In the other species, X. borealis, a younger sex chromosome system exists on a different pair of chromosomes, but the region of suppressed recombination surrounding an unidentified sex determining gene is vast, spanning almost half of the sex chromosomes. Differences between these sex chromosome systems are also apparent in the extent of nucleotide divergence between the sex chromosomes carried by females. Our analyses also indicate that in autosomes of both of these species, recombination during oogenesis occurs more frequently and in different genomic locations than during spermatogenesis. These results demonstrate that new sex chromosomes can assume radically different evolutionary trajectories, with far-reaching genomic consequences. They also suggest that in some instances the origin of new triggers for sex determination may be coupled with rapid evolution sex chromosomes, including recombination suppression of large genomic regions. PMID:29608717

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

    Directory of Open Access Journals (Sweden)

    Na Jong-Kuk

    2012-05-01

    Full Text Available Abstract 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

  3. Comparative AFLP reveals paternal sex ratio chromosome specific DNA sequences in the parasitoid wasp Trichogramma kaykai

    NARCIS (Netherlands)

    Vugt, van J.J.F.A.; Hulst, van der R.G.M.; Pruijssers, A.; Verbaarschot, P.G.H.; Stouthamer, R.; Jong, de H.

    2009-01-01

    The parasitoid wasp Trichogramma kaykai with a haplo-diploid sex determination has a B chromosome called the paternal sex ratio (PSR) chromosome that confers paternal genome loss during early embryogenesis, resulting in male offspring. So far, it is not well known whether the PSR chromosome has

  4. Three loci on mouse chromosome 5 and 10 modulate sex determination in XX Ods/+ mice.

    Science.gov (United States)

    Poirier, Christophe; Moran, Jennifer L; Kovanci, Ertug; Petit, Deborah C; Beier, David R; Bishop, Colin E

    2007-07-01

    In mouse, XY embryos are committed to the male sex determination pathway after the transient expression of the Y-linked Sry gene in the Sertoli cell lineage between 10.5 and 12.5 dpc. In the C57BL/6J strain, male sex determination program can be modulated by some autosomal genes. The C57BL/6J alleles at these autosomal loci can antagonize male sex determination in combination with specific Sry alleles. In this report, the authors have identified an effect of these C57BL/6J specific alleles in combination with a mutated Sox9 allele, Sox9(Ods). Authors report the mapping of three of these genetic loci on mouse chromosome 5 and 10 in a backcross of the Ods mutation to the C57BL/6J background. Our study confirms the importance of the strain C57BL/6J for the investigation of the genetic mechanisms that control sex determination.

  5. Neo-sex chromosomes in the monarch butterfly, Danaus plexippus

    Czech Academy of Sciences Publication Activity Database

    Mongue, A. J.; Nguyen, Petr; Voleníková, Anna; Walters, J. R.

    2017-01-01

    Roč. 7, č. 10 (2017), s. 3281-3294 ISSN 2160-1836 R&D Projects: GA ČR(CZ) GA14-22765S; GA ČR(CZ) GP14-35819P Grant - others:GA JU(CZ) 159/2016/P Institutional support: RVO:60077344 Keywords : sex chromosomes * evolution * Lepidoptera Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 2.861, year: 2016 http://www.g3journal.org/content/7/10/3281.long

  6. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Kohta Yoshida

    2011-08-01

    Full Text Available The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85% in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  7. Sex Chromosome Evolution, Heterochiasmy, and Physiological QTL in the Salmonid Brook Charr Salvelinus fontinalis

    Directory of Open Access Journals (Sweden)

    Ben J.G. Sutherland

    2017-08-01

    Full Text Available Whole-genome duplication (WGD can have large impacts on genome evolution, and much remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex determination system and whether this has an impact on increasing the diversity of sex determination mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can result in sequestration of genes into nonrecombining sex chromosomes. Sex chromosome development itself may involve sex-specific recombination rate (i.e., heterochiasmy, which is also poorly understood. The family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex determining gene is known, and many species have nonhomologous sex chromosomes, putatively due to transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis and compare sex chromosome identities across the lineage (eight species and four genera. Although nonhomology is frequent, homologous sex chromosomes and other consistencies are present in distantly related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome contains a large interspecific inversion, although its status between males and females remains unknown. Finally, we identify quantitative trait loci (QTL for 21 unique growth, reproductive, and stress-related phenotypes to improve knowledge of the genetic

  8. A new physical mapping approach refines the sex-determining gene positions on the Silene latifolia Y-chromosome

    Science.gov (United States)

    Kazama, Yusuke; Ishii, Kotaro; Aonuma, Wataru; Ikeda, Tokihiro; Kawamoto, Hiroki; Koizumi, Ayako; Filatov, Dmitry A.; Chibalina, Margarita; Bergero, Roberta; Charlesworth, Deborah; Abe, Tomoko; Kawano, Shigeyuki

    2016-01-01

    Sex chromosomes are particularly interesting regions of the genome for both molecular genetics and evolutionary studies; yet, for most species, we lack basic information, such as the gene order along the chromosome. Because they lack recombination, Y-linked genes cannot be mapped genetically, leaving physical mapping as the only option for establishing the extent of synteny and homology with the X chromosome. Here, we developed a novel and general method for deletion mapping of non-recombining regions by solving “the travelling salesman problem”, and evaluate its accuracy using simulated datasets. Unlike the existing radiation hybrid approach, this method allows us to combine deletion mutants from different experiments and sources. We applied our method to a set of newly generated deletion mutants in the dioecious plant Silene latifolia and refined the locations of the sex-determining loci on its Y chromosome map.

  9. Using RAD-seq to recognize sex-specific markers and sex chromosome systems.

    Science.gov (United States)

    Gamble, Tony

    2016-05-01

    Next-generation sequencing methods have initiated a revolution in molecular ecology and evolution (Tautz et al. ). Among the most impressive of these sequencing innovations is restriction site-associated DNA sequencing or RAD-seq (Baird et al. ; Andrews et al. ). RAD-seq uses the Illumina sequencing platform to sequence fragments of DNA cut by a specific restriction enzyme and can generate tens of thousands of molecular genetic markers for analysis. One of the many uses of RAD-seq data has been to identify sex-specific genetic markers, markers found in one sex but not the other (Baxter et al. ; Gamble & Zarkower ). Sex-specific markers are a powerful tool for biologists. At their most basic, they can be used to identify the sex of an individual via PCR. This is useful in cases where a species lacks obvious sexual dimorphism at some or all life history stages. For example, such tests have been important for studying sex differences in life history (Sheldon ; Mossman & Waser ), the management and breeding of endangered species (Taberlet et al. ; Griffiths & Tiwari ; Robertson et al. ) and sexing embryonic material (Hacker et al. ; Smith et al. ). Furthermore, sex-specific markers allow recognition of the sex chromosome system in cases where standard cytogenetic methods fail (Charlesworth & Mank ; Gamble & Zarkower ). Thus, species with male-specific markers have male heterogamety (XY) while species with female-specific markers have female heterogamety (ZW). In this issue, Fowler & Buonaccorsi () illustrate the ease by which RAD-seq data can generate sex-specific genetic markers in rockfish (Sebastes). Moreover, by examining RAD-seq data from two closely related rockfish species, Sebastes chrysomelas and Sebastes carnatus (Fig. ), Fowler & Buonaccorsi () uncover shared sex-specific markers and a conserved sex chromosome system. © 2016 John Wiley & Sons Ltd.

  10. Unusual distribution of Zfy and Zfx sequences on the sex chromosomes of the wood lemming, a species exhibiting XY sex reversal.

    Science.gov (United States)

    Lau, Y F; Yang-Feng, T L; Elder, B; Fredga, K; Wiberg, U H

    1992-01-01

    Sex reversal occurs naturally in the wood lemming (Myopus schisticolor) due to the presence in populations of this species of a variant (mutated) X chromosome, designated X*. Thus, X*Y animals develop into females, whereas XY animals develop into normal males. Chromosome mapping by in situ hybridization of DNA sequences homologous to the human ZFY gene localized the wood lemming Zfx sequences to region p12----p11 on both the wild-type X and the mutated X* chromosomes, at or proximal to a presumed breakpoint (Xp12) involved in the generation of the X* chromosome from the normal X, and Zfy sequences along the entire short arm of the Y chromosome. Differences between Zfx and Zfx* were readily detected by Southern blot analysis. However, both the Zfx and Zfx* genes expressed similarly sized transcripts in all adult somatic tissues investigated. Although the precise molecular difference between the Zfx and Zfx* genes is still unknown, their chromosomal location suggests that either Zfx or some other closely linked gene(s) on the X chromosome may be a major X-linked sex-determining gene, Tdx, which in the X* chromosome fails to interact properly with the Y-linked testis-determining gene, Tdy, thus causing X*Y embryos to develop into females. At least 15 copies of wood lemming Zfy sequences are distributed along the short arm of the Y chromosome. Northern hybridization analyses of adult tissues and somatic cell lines indicated that these Zfy repeats were transcriptionally inactive. Normally, 3-kb Zfy (ZFY) transcripts are readily detected in mouse and human testes, especially in the germ cells. It has therefore been postulated that expression of the Zfy (ZFY) gene may be important for spermatogenesis. Whether the lack of sufficient Zfy transcripts in the testis of the adult wood lemming has any impact on spermatogenesis in this species is still to be elucidated by further studies.

  11. Sex chromosome abnormalities and sterility in river buffalo.

    Science.gov (United States)

    Di Meo, G P; Perucatti, A; Di Palo, R; Iannuzzi, A; Ciotola, F; Peretti, V; Neglia, G; Campanile, G; Zicarelli, L; Iannuzzi, L

    2008-01-01

    Thirteen male river buffaloes, 119 females with reproductive problems (which had reached reproductive age but had failed to become pregnant in the presence of bulls) and two male co-twins underwent both clinical and cytogenetic investigation. Clinical analyses performed by veterinary practitioners revealed normal body conformation and external genitalia for most females. However, some subjects showed some slight male traits such as large base horn circumference, prominent withers and tight pelvis. Rectal palpation revealed damage to internal sex adducts varying between atrophy of Mullerian ducts to complete lack of internal sex adducts (with closed vagina). All bulls had normal karyotypes at high resolution banding, while 25 animals (23 females and 2 male co-twins) (20.7%) with reproductive problems were found to carry the following sex chromosome abnormalities: X monosomy (2 females); X trisomy (1 female); sex reversal syndrome (2 females); and free-martinism (18 females and 2 males). All female carriers were sterile. Copyright 2008 S. Karger AG, Basel.

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

    Directory of Open Access Journals (Sweden)

    Kohta Yoshida

    2014-03-01

    Full Text Available 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.

  13. Incomplete sex chromosome dosage compensation in the Indian meal moth, Plodia interpunctella, based on de novo transcriptome assembly.

    Science.gov (United States)

    Harrison, Peter W; Mank, Judith E; Wedell, Nina

    2012-01-01

    Males and females experience differences in gene dose for loci in the nonrecombining region of heteromorphic sex chromosomes. If not compensated, this leads to expression imbalances, with the homogametic sex on average exhibiting greater expression due to the doubled gene dose. Many organisms with heteromorphic sex chromosomes display global dosage compensation mechanisms, which equalize gene expression levels between the sexes. However, birds and Schistosoma have been previously shown to lack chromosome-wide dosage compensation mechanisms, and the status in other female heterogametic taxa including Lepidoptera remains unresolved. To further our understanding of dosage compensation in female heterogametic taxa and to resolve its status in the lepidopterans, we assessed the Indian meal moth, Plodia interpunctella. As P. interpunctella lacks a complete reference genome, we conducted de novo transcriptome assembly combined with orthologous genomic location prediction from the related silkworm genome, Bombyx mori, to compare Z-linked and autosomal gene expression levels for each sex. We demonstrate that P. interpunctella lacks complete Z chromosome dosage compensation, female Z-linked genes having just over half the expression level of males and autosomal genes. This finding suggests that the Lepidoptera and possibly all female heterogametic taxa lack global dosage compensation, although more species will need to be sampled to confirm this assertion.

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

    DEFF Research Database (Denmark)

    Zhou, Qi; Wang, Jun; Huang, Ling

    2008-01-01

    in coding regions of eight investigated genes as well as cis-regulatory regions of two housekeeping genes. In vivo assays characterized a neo-Y insertion in the promoter of the CLTC gene that causes a significant reduction in allelic expression. A neo-Y-linked deletion in the 3'-untranslated region of gene...

  15. Dissociable effects of Sry and sex chromosome complement on activity, feeding and anxiety-related behaviours in mice.

    Science.gov (United States)

    Kopsida, Eleni; Lynn, Phoebe M; Humby, Trevor; Wilkinson, Lawrence S; Davies, William

    2013-01-01

    Whilst gonadal hormones can substantially influence sexual differentiation of the brain, recent findings have suggested that sex-linked genes may also directly influence neurodevelopment. Here we used the well-established murine 'four core genotype' (FCG) model on a gonadally-intact, outbred genetic background to characterise the contribution of Sry-dependent effects (i.e. those arising from the expression of the Y-linked Sry gene in the brain, or from hormonal sequelae of gonadal Sry expression) and direct effects of sex-linked genes other than Sry ('sex chromosome complement' effects) to sexually dimorphic mouse behavioural phenotypes. Over a 24 hour period, XX and XY gonadally female mice (lacking Sry) exhibited greater horizontal locomotor activity and reduced food consumption per unit bodyweight than XX and XY gonadally male mice (possessing Sry); in two behavioural tests (the elevated plus and zero mazes) XX and XY gonadally female mice showed evidence for increased anxiety-related behaviours relative to XX and XY gonadally male mice. Exploratory correlational analyses indicated that these Sry-dependent effects could not be simply explained by brain expression of the gene, nor by circulating testosterone levels. We also noted a sex chromosome complement effect on food (but not water) consumption whereby XY mice consumed more over a 24hr period than XX mice, and a sex chromosome complement effect in a third test of anxiety-related behaviour, the light-dark box. The present data suggest that: i) the male-specific factor Sry may influence activity and feeding behaviours in mice, and ii) dissociable feeding and anxiety-related murine phenotypes may be differentially modulated by Sry and by other sex-linked genes. Our results may have relevance for understanding the molecular underpinnings of sexually dimorphic behavioural phenotypes in healthy men and women, and in individuals with abnormal sex chromosome constitutions.

  16. Dissociable effects of Sry and sex chromosome complement on activity, feeding and anxiety-related behaviours in mice.

    Directory of Open Access Journals (Sweden)

    Eleni Kopsida

    Full Text Available Whilst gonadal hormones can substantially influence sexual differentiation of the brain, recent findings have suggested that sex-linked genes may also directly influence neurodevelopment. Here we used the well-established murine 'four core genotype' (FCG model on a gonadally-intact, outbred genetic background to characterise the contribution of Sry-dependent effects (i.e. those arising from the expression of the Y-linked Sry gene in the brain, or from hormonal sequelae of gonadal Sry expression and direct effects of sex-linked genes other than Sry ('sex chromosome complement' effects to sexually dimorphic mouse behavioural phenotypes. Over a 24 hour period, XX and XY gonadally female mice (lacking Sry exhibited greater horizontal locomotor activity and reduced food consumption per unit bodyweight than XX and XY gonadally male mice (possessing Sry; in two behavioural tests (the elevated plus and zero mazes XX and XY gonadally female mice showed evidence for increased anxiety-related behaviours relative to XX and XY gonadally male mice. Exploratory correlational analyses indicated that these Sry-dependent effects could not be simply explained by brain expression of the gene, nor by circulating testosterone levels. We also noted a sex chromosome complement effect on food (but not water consumption whereby XY mice consumed more over a 24hr period than XX mice, and a sex chromosome complement effect in a third test of anxiety-related behaviour, the light-dark box. The present data suggest that: i the male-specific factor Sry may influence activity and feeding behaviours in mice, and ii dissociable feeding and anxiety-related murine phenotypes may be differentially modulated by Sry and by other sex-linked genes. Our results may have relevance for understanding the molecular underpinnings of sexually dimorphic behavioural phenotypes in healthy men and women, and in individuals with abnormal sex chromosome constitutions.

  17. Differentiation of Sex Chromosomes and Karyotype Characterisation in the Dragonsnake Xenodermus javanicus (Squamata: Xenodermatidae)

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Johnson Pokorná, Martina; Kratochvíl, L.

    2015-01-01

    Roč. 147, č. 1 (2015), s. 48-54 ISSN 1424-8581 Institutional support: RVO:67985904 Keywords : interstitial telomeric repeats * sex chromosomes * sex determination Subject RIV: EG - Zoology Impact factor: 1.638, year: 2015

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

    Science.gov (United States)

    Koubová, Martina; Johnson Pokorná, Martina; Rovatsos, Michail; Farkačová, Klára; Altmanová, Marie; Kratochvíl, Lukáš

    2014-12-01

    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.

  19. Sex chromosome-specific regulation in the Drosophila male germline but little evidence for chromosomal dosage compensation or meiotic inactivation.

    Directory of Open Access Journals (Sweden)

    Colin D Meiklejohn

    2011-08-01

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

  20. Patterns of molecular evolution of an avian neo-sex chromosome.

    Science.gov (United States)

    Pala, Irene; Hasselquist, Dennis; Bensch, Staffan; Hansson, Bengt

    2012-12-01

    Newer parts of sex chromosomes, neo-sex chromosomes, offer unique possibilities for studying gene degeneration and sequence evolution in response to loss of recombination and population size decrease. We have recently described a neo-sex chromosome system in Sylvioidea passerines that has resulted from a fusion between the first half (10 Mb) of chromosome 4a and the ancestral sex chromosomes. In this study, we report the results of molecular analyses of neo-Z and neo-W gametologs and intronic parts of neo-Z and autosomal genes on the second half of chromosome 4a in three species within different Sylvioidea lineages (Acrocephalidea, Timaliidae, and Alaudidae). In line with hypotheses of neo-sex chromosome evolution, we observe 1) lower genetic diversity of neo-Z genes compared with autosomal genes, 2) moderate synonymous and weak nonsynonymous sequence divergence between neo-Z and neo-W gametologs, and 3) lower GC content on neo-W than neo-Z gametologs. Phylogenetic reconstruction of eight neo-Z and neo-W gametologs suggests that recombination continued after the split of Alaudidae from the rest of the Sylvioidea lineages (i.e., after ~42.2 Ma) and with some exceptions also after the split of Acrocephalidea and Timaliidae (i.e., after ~39.4 Ma). The Sylvioidea neo-sex chromosome shares classical evolutionary features with the ancestral sex chromosomes but, as expected from its more recent origin, shows weaker divergence between gametologs.

  1. A role for a neo-sex chromosome in stickleback speciation

    Science.gov (United States)

    Kitano, Jun; Ross, Joseph A.; Mori, Seiichi; Kume, Manabu; Jones, Felicity C.; Chan, Yingguang F.; Absher, Devin M.; Grimwood, Jane; Schmutz, Jeremy; Myers, Richard M.; Kingsley, David M.; Peichel, Catherine L.

    2009-01-01

    Sexual antagonism, or conflict between the sexes, has been proposed as a driving force in both sex chromosome turnover and speciation. Although closely related species often have different sex chromosome systems, it is unknown whether sex chromosome turnover contributes to the evolution of reproductive isolation between species. In this study, we show that a newly evolved sex chromosome harbours genes that contribute to speciation in threespine stickleback fish (Gasterosteus aculeatus). We first identified a neo-sex chromosome system found only in one member of a sympatric species pair in Japan. We then performed genetic linkage mapping of male-specific traits important for reproductive isolation between the Japanese species pair. The neo-X chromosome harbours loci for male courtship display traits that contribute to behavioural isolation, while the ancestral X chromosome contains loci for both behavioural isolation and hybrid male sterility. Our work not only provides strong evidence for a large-X effect on reproductive isolation in a vertebrate system, but also provides direct evidence that a young neo-X chromosome contributes to reproductive isolation between closely related species. Our data suggest that sex chromosome turnover might play a greater role in speciation than previously appreciated. PMID:19783981

  2. Meiotic sex chromosome inactivation is disrupted in sterile hybrid male house mice.

    Science.gov (United States)

    Campbell, Polly; Good, Jeffrey M; Nachman, Michael W

    2013-03-01

    In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid male sterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis.

  3. Caenorhabditis elegans histone methyltransferase MET-2 shields the male X chromosome from checkpoint machinery and mediates meiotic sex chromosome inactivation.

    Directory of Open Access Journals (Sweden)

    Paula M Checchi

    2011-09-01

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

  4. Impaired imprinted X chromosome inactivation is responsible for the skewed sex ratio following in vitro fertilization

    Science.gov (United States)

    Tan, Kun; An, Lei; Miao, Kai; Ren, Likun; Hou, Zhuocheng; Tao, Li; Zhang, Zhenni; Wang, Xiaodong; Xia, Wei; Liu, Jinghao; Wang, Zhuqing; Xi, Guangyin; Gao, Shuai; Sui, Linlin; Zhu, De-Sheng; Wang, Shumin; Wu, Zhonghong; Bach, Ingolf; Chen, Dong-bao; Tian, Jianhui

    2016-01-01

    Dynamic epigenetic reprogramming occurs during normal embryonic development at the preimplantation stage. Erroneous epigenetic modifications due to environmental perturbations such as manipulation and culture of embryos during in vitro fertilization (IVF) are linked to various short- or long-term consequences. Among these, the skewed sex ratio, an indicator of reproductive hazards, was reported in bovine and porcine embryos and even human IVF newborns. However, since the first case of sex skewing reported in 1991, the underlying mechanisms remain unclear. We reported herein that sex ratio is skewed in mouse IVF offspring, and this was a result of female-biased peri-implantation developmental defects that were originated from impaired imprinted X chromosome inactivation (iXCI) through reduced ring finger protein 12 (Rnf12)/X-inactive specific transcript (Xist) expression. Compensation of impaired iXCI by overexpression of Rnf12 to up-regulate Xist significantly rescued female-biased developmental defects and corrected sex ratio in IVF offspring. Moreover, supplementation of an epigenetic modulator retinoic acid in embryo culture medium up-regulated Rnf12/Xist expression, improved iXCI, and successfully redeemed the skewed sex ratio to nearly 50% in mouse IVF offspring. Thus, our data show that iXCI is one of the major epigenetic barriers for the developmental competence of female embryos during preimplantation stage, and targeting erroneous epigenetic modifications may provide a potential approach for preventing IVF-associated complications. PMID:26951653

  5. The mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma represents a model for early evolution of sex chromosomes.

    Directory of Open Access Journals (Sweden)

    Audrius Menkis

    2008-03-01

    Full Text Available We combined gene divergence data, classical genetics, and phylogenetics to study the evolution of the mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma. In this species, a large non-recombining region of the mating-type chromosome is associated with a unique fungal life cycle where self-fertility is enforced by maintenance of a constant state of heterokaryosis. Sequence divergence between alleles of 35 genes from the two single mating-type component strains (i.e. the homokaryotic mat A or mat a-strains, derived from one N. tetrasperma heterokaryon (mat A+mat a, was analyzed. By this approach we were able to identify the boundaries and size of the non-recombining region, and reveal insight into the history of recombination cessation. The non-recombining region covers almost 7 Mbp, over 75% of the chromosome, and we hypothesize that the evolution of the mating-type chromosome in this lineage involved two successive events. The first event was contemporaneous with the split of N. tetrasperma from a common ancestor with its outcrossing relative N. crassa and suppressed recombination over at least 6.6 Mbp, and the second was confined to a smaller region in which recombination ceased more recently. In spite of the early origin of the first "evolutionary stratum", genealogies of five genes from strains belonging to an additional N. tetrasperma lineage indicate independent initiations of suppressed recombination in different phylogenetic lineages. This study highlights the shared features between the sex chromosomes found in the animal and plant kingdoms and the fungal mating-type chromosome, despite fungi having no separate sexes. As is often found in sex chromosomes of plants and animals, recombination suppression of the mating-type chromosome of N. tetrasperma involved more than one evolutionary event, covers the majority of the mating-type chromosome and is flanked by distal regions with obligate crossovers.

  6. First Description of the Karyotype and Sex Chromosomes in the Komodo Dragon (Varanus komodoensis).

    Science.gov (United States)

    Johnson Pokorná, Martina; Altmanová, Marie; Rovatsos, Michail; Velenský, Petr; Vodička, Roman; Rehák, Ivan; Kratochvíl, Lukáš

    2016-01-01

    The Komodo dragon (Varanus komodoensis) is the largest lizard in the world. Surprisingly, it has not yet been cytogenetically examined. Here, we present the very first description of its karyotype and sex chromosomes. The karyotype consists of 2n = 40 chromosomes, 16 macrochromosomes and 24 microchromosomes. Although the chromosome number is constant for all species of monitor lizards (family Varanidae) with the currently reported karyotype, variability in the morphology of the macrochromosomes has been previously documented within the group. We uncovered highly differentiated ZZ/ZW sex microchromosomes with a heterochromatic W chromosome in the Komodo dragon. Sex chromosomes have so far only been described in a few species of varanids including V. varius, the sister species to Komodo dragon, whose W chromosome is notably larger than that of the Komodo dragon. Accumulations of several microsatellite sequences in the W chromosome have recently been detected in 3 species of monitor lizards; however, these accumulations are absent from the W chromosome of the Komodo dragon. In conclusion, although varanids are rather conservative in karyotypes, their W chromosomes exhibit substantial variability at the sequence level, adding further evidence that degenerated sex chromosomes may represent the most dynamic genome part. © 2016 S. Karger AG, Basel.

  7. Rapid molecular sexing of three-spined sticklebacks, Gasterosteus aculeatus L., based on large Y-chromosomal insertions.

    Science.gov (United States)

    Bakker, Theo C M; Giger, Thomas; Frommen, Joachim G; Largiadèr, Carlo R

    2017-08-01

    There is a need for rapid and reliable molecular sexing of three-spined sticklebacks, Gasterosteus aculeatus, the supermodel species for evolutionary biology. A DNA region at the 5' end of the sex-linked microsatellite Gac4202 was sequenced for the X chromosome of six females and the Y chromosome of five males from three populations. The Y chromosome contained two large insertions, which did not recombine with the phenotype of sex in a cross of 322 individuals. Genetic variation (SNPs and indels) within the insertions was smaller than on flanking DNA sequences. Three molecular PCR-based sex tests were developed, in which the first, the second or both insertions were covered. In five European populations (from DE, CH, NL, GB) of three-spined sticklebacks, tests with both insertions combined showed two clearly separated bands on agarose minigels in males and one band in females. The tests with the separate insertions gave similar results. Thus, the new molecular sexing method gave rapid and reliable results for sexing three-spined sticklebacks and is an improvement and/or alternative to existing methods.

  8. Rapid neo-sex chromosome evolution and incipient speciation in a major forest pest.

    Science.gov (United States)

    Bracewell, Ryan R; Bentz, Barbara J; Sullivan, Brian T; Good, Jeffrey M

    2017-11-17

    Genome evolution is predicted to be rapid following the establishment of new (neo) sex chromosomes, but it is not known if neo-sex chromosome evolution plays an important role in speciation. Here we combine extensive crossing experiments with population and functional genomic data to examine neo-XY chromosome evolution and incipient speciation in the mountain pine beetle. We find a broad continuum of intrinsic incompatibilities in hybrid males that increase in strength with geographic distance between reproductively isolated populations. This striking progression of reproductive isolation is coupled with extensive gene specialization, natural selection, and elevated genetic differentiation on both sex chromosomes. Closely related populations isolated by hybrid male sterility also show fixation of alternative neo-Y haplotypes that differ in structure and male-specific gene content. Our results suggest that neo-sex chromosome evolution can drive rapid functional divergence between closely related populations irrespective of ecological drivers of divergence.

  9. Dynamics of vertebrate sex chromosome evolution: from equal size to giants and dwarfs.

    Science.gov (United States)

    Schartl, Manfred; Schmid, Michael; Nanda, Indrajit

    2016-06-01

    The Y and W chromosomes of mammals and birds are known to be small because most of their genetic content degenerated and were lost due to absence of recombination with the X or Z, respectively. Thus, a picture has emerged of ever-shrinking Ys and Ws that may finally even fade into disappearance. We review here the large amount of literature on sex chromosomes in vertebrate species and find by taking a closer look, particularly at the sex chromosomes of fishes, amphibians and reptiles where several groups have evolutionary younger chromosomes than those of mammals and birds, that the perception of sex chromosomes being doomed to size reduction is incomplete. Here, sex-determining mechanisms show a high turnover and new sex chromosomes appear repeatedly. In many species, Ys and Ws are larger than their X and Z counterparts. This brings up intriguing perspectives regarding the evolutionary dynamics of sex chromosomes. It can be concluded that, due to accumulation of repetitive DNA and transposons, the Y and W chromosomes can increase in size during the initial phase of their differentiation.

  10. Repetitive sequences and epigenetic modification: inseparable partners play important roles in the evolution of plant sex chromosomes.

    Science.gov (United States)

    Li, Shu-Fen; Zhang, Guo-Jun; Yuan, Jin-Hong; Deng, Chuan-Liang; Gao, Wu-Jun

    2016-05-01

    The present review discusses the roles of repetitive sequences played in plant sex chromosome evolution, and highlights epigenetic modification as potential mechanism of repetitive sequences involved in sex chromosome evolution. Sex determination in plants is mostly based on sex chromosomes. Classic theory proposes that sex chromosomes evolve from a specific pair of autosomes with emergence of a sex-determining gene(s). Subsequently, the newly formed sex chromosomes stop recombination in a small region around the sex-determining locus, and over time, the non-recombining region expands to almost all parts of the sex chromosomes. Accumulation of repetitive sequences, mostly transposable elements and tandem repeats, is a conspicuous feature of the non-recombining region of the Y chromosome, even in primitive one. Repetitive sequences may play multiple roles in sex chromosome evolution, such as triggering heterochromatization and causing recombination suppression, leading to structural and morphological differentiation of sex chromosomes, and promoting Y chromosome degeneration and X chromosome dosage compensation. In this article, we review the current status of this field, and based on preliminary evidence, we posit that repetitive sequences are involved in sex chromosome evolution probably via epigenetic modification, such as DNA and histone methylation, with small interfering RNAs as the mediator.

  11. Increased high-density lipoprotein cholesterol levels in mice with XX versus XY sex chromosomes.

    Science.gov (United States)

    Link, Jenny C; Chen, Xuqi; Prien, Christopher; Borja, Mark S; Hammerson, Bradley; Oda, Michael N; Arnold, Arthur P; Reue, Karen

    2015-08-01

    The molecular mechanisms underlying sex differences in dyslipidemia are poorly understood. We aimed to distinguish genetic and hormonal regulators of sex differences in plasma lipid levels. We assessed the role of gonadal hormones and sex chromosome complement on lipid levels using the four core genotypes mouse model (XX females, XX males, XY females, and XY males). In gonadally intact mice fed a chow diet, lipid levels were influenced by both male-female gonadal sex and XX-XY chromosome complement. Gonadectomy of adult mice revealed that the male-female differences are dependent on acute effects of gonadal hormones. In both intact and gonadectomized animals, XX mice had higher HDL cholesterol (HDL-C) levels than XY mice, regardless of male-female sex. Feeding a cholesterol-enriched diet produced distinct patterns of sex differences in lipid levels compared with a chow diet, revealing the interaction of gonadal and chromosomal sex with diet. Notably, under all dietary and gonadal conditions, HDL-C levels were higher in mice with 2 X chromosomes compared with mice with an X and Y chromosome. By generating mice with XX, XY, and XXY chromosome complements, we determined that the presence of 2 X chromosomes, and not the absence of the Y chromosome, influences HDL-C concentration. We demonstrate that having 2 X chromosomes versus an X and Y chromosome complement drives sex differences in HDL-C. It is conceivable that increased expression of genes escaping X-inactivation in XX mice regulates downstream processes to establish sexual dimorphism in plasma lipid levels. © 2015 American Heart Association, Inc.

  12. Conservation of Sex-Linked Markers among Conspecific Populations of a Viviparous Skink, Niveoscincus ocellatus, Exhibiting Genetic and Temperature-Dependent Sex Determination

    Science.gov (United States)

    Burridge, Christopher P; Ezaz, Tariq; Wapstra, Erik

    2018-01-01

    Abstract Sex determination systems are exceptionally diverse and have undergone multiple and independent evolutionary transitions among species, particularly reptiles. However, the mechanisms underlying these transitions have not been established. Here, we tested for differences in sex-linked markers in the only known reptile that is polymorphic for sex determination system, the spotted snow skink, Niveoscincus ocellatus, to quantify the genomic differences that have accompanied this transition. In a highland population, sex is determined genetically, whereas in a lowland population, offspring sex ratio is influenced by temperature. We found a similar number of sex-linked loci in each population, including shared loci, with genotypes consistent with male heterogamety (XY). However, population-specific linkage disequilibrium suggests greater differentiation of sex chromosomes in the highland population. Our results suggest that transitions between sex determination systems can be facilitated by subtle genetic differences. PMID:29659810

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

    Directory of Open Access Journals (Sweden)

    Najmeh Jouyan

    2012-01-01

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

  14. Multiple sex-associated regions and a putative sex chromosome in zebrafish revealed by RAD mapping and population genomics.

    Directory of Open Access Journals (Sweden)

    Jennifer L Anderson

    Full Text Available 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 F(2 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.

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

    Czech Academy of Sciences Publication Activity Database

    Koubová, M.; Johnson Pokorná, Martina; Rovatsos, M.; Farkačová, K.; Altmanová, M.; Kratochvíl, L.

    2014-01-01

    Roč. 22, č. 4 (2014), s. 441-452 ISSN 0967-3849 R&D Projects: GA ČR GAP506/10/0718 Institutional support: RVO:67985904 Keywords : sex chromosomes * heterochromatin * reptiles * sex determination * FISH * ITSs Subject RIV: EG - Zoology Impact factor: 2.478, year: 2014

  16. Sex differences in the brain-an interplay of sex steroid hormones and sex chromosomes.

    Science.gov (United States)

    Grgurevic, Neza; Majdic, Gregor

    2016-09-01

    Although considerable progress has been made in our understanding of brain function, many questions remain unanswered. The ultimate goal of studying the brain is to understand the connection between brain structure and function and behavioural outcomes. Since sex differences in brain morphology were first observed, subsequent studies suggest different functional organization of the male and female brains in humans. Sex and gender have been identified as being a significant factor in understanding human physiology, health and disease, and the biological differences between the sexes is not limited to the gonads and secondary sexual characteristics, but also affects the structure and, more crucially, the function of the brain and other organs. Significant variability in brain structures between individuals, in addition to between the sexes, is factor that complicates the study of sex differences in the brain. In this review, we explore the current understanding of sex differences in the brain, mostly focusing on preclinical animal studies. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  17. The chromosomal distribution of microsatellite repeats in the genome of the wolf fish Hoplias malabaricus, focusing on the sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Cioffi, M.B.; Kejnovský, Eduard; Bertollo, L.A.C.

    2011-01-01

    Roč. 132, č. 4 (2011), s. 289-296 ISSN 1424-8581 R&D Projects: GA ČR(CZ) GAP305/10/0930 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : fish sex chromosomes * fluorescence in situ hybridization * microsatellites Subject RIV: BO - Biophysics Impact factor: 1.533, year: 2011

  18. Familial hemiplegic migraine: a clinical comparison of families linked and unlinked to chromosome 19.DMG RG.

    Science.gov (United States)

    Terwindt, G M; Ophoff, R A; Haan, J; Frants, R R; Ferrari, M D

    1996-05-01

    We compared the clinical characteristics of 46 patients from three unrelated families with familial hemiplegic migraine (FHM) linked to chromosome 19, with those of 20 patients from two families with FHM not linked to chromosome 19. We found no significant differences for age at onset, frequency and duration of attacks, duration of the paresis, and occurrence of basilar migraine symptoms. In the linked families, significantly more patients reported unconsciousness during attacks (39% vs 15%; p < 0.05) and provocation of attacks by mild head trauma (70% vs 40%; p < 0.05). In one linked family patients also displayed chronic progressive cerebellar ataxia, whereas in one unlinked family benign infantile convulsions occurred in addition to FHM. Interestingly, so far an association with cerebellar ataxia was only described in chromosome 19-linked families. FHM linked to chromosome 19 and FHM unlinked to chromosome 19 do not differ with respect to clinical features.

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

    Science.gov (United States)

    Mank, Judith E

    2012-01-01

    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.

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

    Science.gov (United States)

    2012-01-01

    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

  1. Weird mammals provide insights into the evolution of mammalian sex chromosomes and dosage compensation.

    Science.gov (United States)

    Graves, Jennifer A Marshall

    2015-12-01

    The deep divergence of mammalian groups 166 and 190 million years ago (MYA) provide genetic variation to explore the evolution of DNA sequence, gene arrangement and regulation of gene expression in mammals. With encouragement from the founder of the field, Mary Lyon, techniques in cytogenetics and molecular biology were progressively adapted to characterize the sex chromosomes of kangaroos and other marsupials, platypus and echidna-and weird rodent species. Comparative gene mapping reveals the process of sex chromosome evolution from their inception 190 MYA (they are autosomal in platypus) to their inevitable end (the Y has disappeared in two rodent lineages). Our X and Y are relatively young, getting their start with the evolution of the sex-determining SRY gene, which triggered progressive degradation of the Y chromosome. Even more recently, sex chromosomes of placental mammals fused with an autosomal region which now makes up most of the Y. Exploration of gene activity patterns over four decades showed that dosage compensation via X-chromosome inactivation is unique to therian mammals, and that this whole chromosome control process is different in marsupials and absent in monotremes and reptiles, and birds. These differences can be exploited to deduce how mammalian sex chromosomes and epigenetic silencing evolved.

  2. Asymmetry of cerebral grey and white matter and structural volumes in relation to sex hormones and chromosomes

    Directory of Open Access Journals (Sweden)

    Ivanka eSavic

    2014-11-01

    Full Text Available Whilst many studies show sex differences in cerebral asymmetry, their mechanisms are still unknown. This report describes the potential impact of sex hormones and sex chromosomes by comparing MR data from 39 male and 47 female controls and 33 men with an extra X-chromosome (47,XXY Methods: Regional asymmetry in grey and white matter volumes (GMV and WMV was calculated using voxel based moprhometry (SPM5, by contrasting the unflipped and flipped individual GMV and WMV images. In addition, structural volumes were calculated for the thalamus, caudate, putamen, amygdala, and hippocampus, using the FreeSurfer software. Effects of plasma testosterone and estrogen on the GMV and WMV, as well on the right/left ratios of the subcortical volumes were tested by multi-regression analysis.Results: All three groups showed a leftward asymmetry in the motor cortex and the planum temporale, and a rightward asymmetry of the middle occipital cortex. Both asymmetries were more pronounced in 46,XY males than 46,XX females and 47,XXY males, and were positively correlated with testosterone levels. There was also a rightward asymmetry of the vermis and leftward asymmetry in the cerebellar hemispheres in all groups. Notably, cerebellar asymmetries were larger in 46,XX females and 47,XXY males, but were not related to sex hormone levels. No asymmetry differences between 46,XX females and 47,XXY males, and no overall effects of brain size were detected.Conclusion: The asymmetry in the planum temporale area and the occipital cortex seem related to processes associated with testosterone, whereas the observed cerebellar asymmetries suggest a link with X-chromosome escapee genes. Sex differences in cerebral asymmetry are moderated by sex hormones and X-chromosome genes, in a regionally differentiated manner.

  3. Asymmetry of cerebral gray and white matter and structural volumes in relation to sex hormones and chromosomes.

    Science.gov (United States)

    Savic, Ivanka

    2014-01-01

    Whilst many studies show sex differences in cerebral asymmetry, their mechanisms are still unknown. This report describes the potential impact of sex hormones and sex chromosomes by comparing MR data from 39 male and 47 female controls and 33 men with an extra X-chromosome (47,XXY). Regional asymmetry in gray and white matter volumes (GMV and WMV) was calculated using voxel based moprhometry (SPM5), by contrasting the unflipped and flipped individual GMV and WMV images. In addition, structural volumes were calculated for the thalamus, caudate, putamen, amygdala, and hippocampus, using the FreeSurfer software. Effects of plasma testosterone and estrogen on the GMV and WMV, as well on the right/left ratios of the subcortical volumes were tested by multi-regression analysis. All three groups showed a leftward asymmetry in the motor cortex and the planum temporale, and a rightward asymmetry of the middle occipital cortex. Both asymmetries were more pronounced in 46,XY males than 46,XX females and 47,XXY males, and were positively correlated with testosterone levels. There was also a rightward asymmetry of the vermis and leftward GMV asymmetry in the cerebellar hemispheres in all groups. Notably, cerebellar asymmetries were larger in 46,XX females and 47,XXY males, but were not related to sex hormone levels. No asymmetry differences between 46,XX females and 47,XXY males, and no overall effects of brain size were detected. The asymmetry in the planum temporale area and the occipital cortex seem related to processes associated with testosterone, whereas the observed cerebellar asymmetries suggest a link with X-chromosome escapee genes. Sex differences in cerebral asymmetry are moderated by sex hormones and X-chromosome genes, in a regionally differentiated manner.

  4. Differentiation of sex chromosomes and karyotypic evolution in the eye-lid geckos (Squamata: Gekkota: Eublepharidae), a group with different modes of sex determination.

    Science.gov (United States)

    Pokorná, Martina; Rábová, Marie; Ráb, Petr; Ferguson-Smith, Malcolm A; Rens, Willem; Kratochvíl, Lukáš

    2010-11-01

    The eyelid geckos (family Eublepharidae) include both species with temperature-dependent sex determination and species where genotypic sex determination (GSD) was suggested based on the observation of equal sex ratios at several incubation temperatures. In this study, we present data on karyotypes and chromosomal characteristics in 12 species (Aeluroscalabotes felinus, Coleonyx brevis, Coleonyx elegans, Coleonyx variegatus, Eublepharis angramainyu, Eublepharis macularius, Goniurosaurus araneus, Goniurosaurus lichtenfelderi, Goniurosaurus luii, Goniurosaurus splendens, Hemitheconyx caudicinctus, and Holodactylus africanus) covering all genera of the family, and search for the presence of heteromorphic sex chromosomes. Phylogenetic mapping of chromosomal changes showed a long evolutionary stasis of karyotypes with all acrocentric chromosomes followed by numerous chromosomal rearrangements in the ancestors of two lineages. We have found heteromorphic sex chromosomes in only one species, which suggests that sex chromosomes in most GSD species of the eyelid geckos are not morphologically differentiated. The sexual difference in karyotype was detected only in C. elegans which has a multiple sex chromosome system (X(1)X(2)Y). The metacentric Y chromosome evolved most likely via centric fusion of two acrocentric chromosomes involving loss of interstitial telomeric sequences. We conclude that the eyelid geckos exhibit diversity in sex determination ranging from the absence of any sexual differences to heteromorphic sex chromosomes, which makes them an interesting system for exploring the evolutionary origin of sexually dimorphic genomes.

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

    Directory of Open Access Journals (Sweden)

    Mikhail G Divashuk

    Full Text Available 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Fully automated pipeline for detection of sex linked genes using RNA-Seq data.

    Science.gov (United States)

    Michalovova, Monika; Kubat, Zdenek; Hobza, Roman; Vyskot, Boris; Kejnovsky, Eduard

    2015-03-11

    Sex chromosomes present a genomic region which to some extent, differs between the genders of a single species. Reliable high-throughput methods for detection of sex chromosomes specific markers are needed, especially in species where genome information is limited. Next generation sequencing (NGS) opens the door for identification of unique sequences or searching for nucleotide polymorphisms between datasets. A combination of classical genetic segregation analysis along with RNA-Seq data can present an ideal tool to map and identify sex chromosome-specific expressed markers. To address this challenge, we established genetic cross of dioecious plant Rumex acetosa and generated RNA-Seq data from both parental generation and male and female offspring. We present a pipeline for detection of sex linked genes based on nucleotide polymorphism analysis. In our approach, tracking of nucleotide polymorphisms is carried out using a cross of preferably distant populations. For this reason, only 4 datasets are needed - reads from high-throughput sequencing platforms for parent generation (mother and father) and F1 generation (male and female progeny). Our pipeline uses custom scripts together with external assembly, mapping and variant calling software. Given the resource-intensive nature of the computation, servers with high capacity are a requirement. Therefore, in order to keep this pipeline easily accessible and reproducible, we implemented it in Galaxy - an open, web-based platform for data-intensive biomedical research. Our tools are present in the Galaxy Tool Shed, from which they can be installed to any local Galaxy instance. As an output of the pipeline, user gets a FASTA file with candidate transcriptionally active sex-linked genes, sorted by their relevance. At the same time, a BAM file with identified genes and alignment of reads is also provided. Thus, polymorphisms following segregation pattern can be easily visualized, which significantly enhances primer design

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

    Science.gov (United States)

    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...

  9. Sex-Linked Behavior: Evolution, Stability, and Variability.

    Science.gov (United States)

    Fine, Cordelia; Dupré, John; Joel, Daphna

    2017-09-01

    Common understanding of human sex-linked behaviors is that proximal mechanisms of genetic and hormonal sex, ultimately shaped by the differential reproductive challenges of ancestral males and females, act on the brain to transfer sex-linked predispositions across generations. Here, we extend the debate on the role of nature and nurture in the development of traits in the lifetime of an individual, to their role in the cross-generation transfer of traits. Advances in evolutionary theory that posit the environment as a source of trans-generational stability, and new understanding of sex effects on the brain, suggest that the cross-generation stability of sex-linked patterns of behavior are sometimes better explained in terms of inherited socioenvironmental conditions, with biological sex fostering intrageneration variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Postzygotic isolation involves strong mitochondrial and sex-specific effects in Tigriopus californicus, a species lacking heteromorphic sex chromosomes.

    Science.gov (United States)

    Foley, B R; Rose, C G; Rundle, D E; Leong, W; Edmands, S

    2013-11-01

    Detailed studies of the genetics of speciation have focused on a few model systems, particularly Drosophila. The copepod Tigriopus californicus offers an alternative that differs from standard animal models in that it lacks heteromorphic chromosomes (instead, sex determination is polygenic) and has reduced opportunities for sexual conflict, because females mate only once. Quantitative trait loci (QTL) mapping was conducted on reciprocal F2 hybrids between two strongly differentiated populations, using a saturated linkage map spanning all 12 autosomes and the mitochondrion. By comparing sexes, a possible sex ratio distorter was found but no sex chromosomes. Although studies of standard models often find an excess of hybrid male sterility factors, we found no QTL for sterility and multiple QTL for hybrid viability (indicated by non-Mendelian adult ratios) and other characters. Viability problems were found to be stronger in males, but the usual explanations for weaker hybrid males (sex chromosomes, sensitivity of spermatogenesis, sexual selection) cannot fully account for these male viability problems. Instead, higher metabolic rates may amplify deleterious effects in males. Although many studies of standard speciation models find the strongest genetic incompatibilities to be nuclear-nuclear (specifically X chromosome-autosome), we found the strongest deleterious interaction in this system was mito-nuclear. Consistent with the snowball theory of incompatibility accumulation, we found that trigenic interactions in this highly divergent cross were substantially more frequent (>6×) than digenic interactions. This alternative system thus allows important comparisons to studies of the genetics of reproductive isolation in more standard model systems.

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

    Science.gov (United States)

    Seu, Emanuele; Groman, Stephanie M; Arnold, Arthur P; Jentsch, J David

    2014-07-01

    The procurement and consumption of palatable, calorie-dense foods is influenced by the nutritional and hedonic value of foods. Although many factors can influence the control over behavior by foods rich in sugar and fat, emerging evidence indicates that biological sex may play a particularly crucial role in the types of foods individuals seek out, as well as the level of motivation individuals will exert to obtain those foods. However, a systematic investigation of food-seeking and consumption that disentangles the effects of the major sex-biasing factors, including sex chromosome complement and organizational and activational effects of sex hormones, has yet to be conducted. Using the four core genotypes mouse model system, we separated and quantified the effects of sex chromosome complement and gonadal sex on consumption of and motivation to obtain a highly palatable solution [sweetened condensed milk (SCM)]. Gonadectomized mice with an XY sex chromosome complement, compared with those with two X chromosomes, independent of gonadal sex, appeared to be more sensitive to the reward value of the SCM solution and were more motivated to expend effort to obtain it, as evidenced by their dramatically greater expended effort in an instrumental task with progressively larger response-to-reward ratios. Gonadal sex independently affected free consumption of the solution but not motivation to obtain it. These data indicate that gonadal and chromosomal sex effects independently influence reward-related behaviors, contributing to sexually dimorphic patterns of behavior related to the pursuit and consumption of rewards. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  12. Review Recent progress in identification and characterization of loci associated with sex-linked congenital cataract.

    Science.gov (United States)

    Zhang, D D; Du, J Z; Topolewski, J; Wang, X M

    2016-07-29

    Congenital cataract is a common cause of blindness in children; however, its pathogenesis remains unclear. Genetic factors have been shown to play an important role in the pathogenesis of congenital cataract. The current genetic models of congenital cataract include autosomal dominant, autosomal recessive, and sex-linked inheritance. Sex-linked congenital cataract could be inherited through the X or Y chromosome. Congenital cataract is a symptom associated with several X-linked disorders, including Nance-Horan syndrome, Lowe syndrome, Conradi-Hünermann-Happle syndrome, oculo-facio-cardio-dental syndrome, and Alport syndrome. On the other hand, the mechanism and characteristics of Y-linked congenital cataract remains to be identified. Despite its rarity, sex-linked congenital cataract has been known to seriously affect the quality of life of patients. In this review, we present our current understanding of the genes and loci associated with sex-linked congenital cataract. This could help identify novel approaches for the prevention, early diagnosis, and comprehensive disease treatment.

  13. Genetic Diversity in the UV Sex Chromosomes of the Brown Alga Ectocarpus.

    Science.gov (United States)

    Avia, Komlan; Lipinska, Agnieszka P; Mignerot, Laure; Montecinos, Alejandro E; Jamy, Mahwash; Ahmed, Sophia; Valero, Myriam; Peters, Akira F; Cock, J Mark; Roze, Denis; Coelho, Susana M

    2018-06-06

    Three types of sex chromosome system exist in nature: diploid XY and ZW systems and haploid UV systems. For many years, research has focused exclusively on XY and ZW systems, leaving UV chromosomes and haploid sex determination largely neglected. Here, we perform a detailed analysis of DNA sequence neutral diversity levels across the U and V sex chromosomes of the model brown alga Ectocarpus using a large population dataset. We show that the U and V non-recombining regions of the sex chromosomes (SDR) exhibit about half as much neutral diversity as the autosomes. This difference is consistent with the reduced effective population size of these regions compared with the rest of the genome, suggesting that the influence of additional factors such as background selection or selective sweeps is minimal. The pseudoautosomal region (PAR) of this UV system, in contrast, exhibited surprisingly high neutral diversity and there were several indications that genes in this region may be under balancing selection. The PAR of Ectocarpus is known to exhibit unusual genomic features and our results lay the foundation for further work aimed at understanding whether, and to what extent, these structural features underlie the high level of genetic diversity. Overall, this study fills a gap between available information on genetic diversity in XY/ZW systems and UV systems and significantly contributes to advancing our knowledge of the evolution of UV sex chromosomes.

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

    Science.gov (United States)

    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

    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. © 2013 S. Karger AG, Basel.

  15. Genomic regions associated with the sex-linked inhibitor of dermal melanin in Silkie chicken

    Directory of Open Access Journals (Sweden)

    Ming TIAN,Rui HAO,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Xiaoxiang HU,Ning LI

    2014-09-01

    Full Text Available A unique characteristic of the Silkie chicken is its fibromelanosis phenotype. The dermal layer of its skin, its connective tissue and shank dermis are hyperpigmented. This dermal hyperpigmentation phenotype is controlled by the sex-linked inhibitor of dermal melanin gene (ID and the dominant fibromelanosis allele. This study attempted to confirm the genomic region associated with ID. By genotyping, ID was found to be closely linked to the region between GGA_rs16127903 and GGA_rs14685542 (8406919 bp on chromosome Z, which contains ten functional genes. The expression of these genes was characterized in the embryo and 4 days after hatching and it was concluded that MTAP, encoding methylthioadenosinephosphorylase, would be the most likely candidate gene. Finally, target DNA capture and sequence analysis was performed, but no specific SNP(s was found in the targeted region of the Silkie genome. Further work is necessary to identify the causal ID mutation located on chromosome Z.

  16. The fate of W chromosomes in hybrids between wild silkmoths, Samia cynthia ssp.: no role in sex determination and reproduction.

    Science.gov (United States)

    Yoshido, A; Marec, F; Sahara, K

    2016-05-01

    Moths and butterflies (Lepidoptera) have sex chromosome systems with female heterogamety (WZ/ZZ or derived variants). The maternally inherited W chromosome is known to determine female sex in the silkworm, Bombyx mori. However, little is known about the role of W chromosome in other lepidopteran species. Here we describe two forms of the W chromosome, W and neo-W, that are transmitted to both sexes in offspring of hybrids from reciprocal crosses between subspecies of wild silkmoths, Samia cynthia. We performed crosses between S. c. pryeri (2n=28, WZ/ZZ) and S. c. walkeri (2n=26, neo-Wneo-Z/neo-Zneo-Z) and examined fitness and sex chromosome constitution in their hybrids. The F1 hybrids of both reciprocal crosses had reduced fertility. Fluorescence in situ hybridization revealed not only the expected sex chromosome constitutions in the backcross and F2 hybrids of both sexes but also females without the W (or neo-W) chromosome and males carrying the W (or neo-W) chromosome. Furthermore, crosses between the F2 hybrids revealed no association between the presence or absence of W (or neo-W) chromosome and variations in the hatchability of their eggs. Our results clearly suggest that the W (or neo-W) chromosome of S. cynthia ssp. plays no role in sex determination and reproduction, and thus does not contribute to the formation of reproductive barriers between different subspecies.

  17. To Break or Not To Break: Sex Chromosome Hemizygosity During Meiosis in Caenorhabditis.

    Science.gov (United States)

    Van, Mike V; Larson, Braden J; Engebrecht, JoAnne

    2016-11-01

    Meiotic recombination establishes connections between homologous chromosomes to promote segregation. Hemizygous regions of sex chromosomes have no homologous chromosome to recombine with, yet must be transmitted through meiosis. An extreme case of hemizygosity exists in the genus Caenorhabditis, where males have a single X chromosome that completely lacks a homologous partner. To determine whether similar strategies have evolved to accommodate hemizygosity of the X during male meiosis in Caenorhabditis with distinct modes of sexual reproduction, we examined induction and processing of meiotic double strand breaks (DSBs) in androdioecious (hermaphrodite/male) Caenorhabditis elegans and C. briggsae, and gonochoristic (female/male) C. remanei and C. brenneri Analysis of the recombinase RAD-51 suggests more meiotic DSBs are induced in gonochoristic vs. androdioecious species. However, in late prophase in all species, chromosome pairs are restructured into bivalents around a single axis, suggesting that the holocentric nature of Caenorhabditis chromosomes dictates a single crossover per bivalent regardless of the number of DSBs induced. Interestingly, RAD-51 foci were readily observed on the X chromosome of androdioecious male germ cells, while very few were detected in gonochoristic male germ cells. As in C. elegans, the X chromosome in C. briggsae male germ cells undergoes transient pseudosynapsis and flexibility in DSB repair pathway choice. In contrast, in C. remanei and C. brenneri male germ cells, the X chromosome does not undergo pseudosynapsis and appears refractory to SPO-11-induced breaks. Together our results suggest that distinct strategies have evolved to accommodate sex chromosome hemizygosity during meiosis in closely related Caenorhabditis species. Copyright © 2016 by the Genetics Society of America.

  18. Chromosome

    Science.gov (United States)

    ... St Louis, MO: Elsevier; 2017:chap 69. Taber's Medical Dictionary Online. Chromosome. www.tabers.com/tabersonline/view/Tabers-Dictionary/753321/all/chromosome?q=Chromosome&ti=0 . Accessed June 11, 2017.

  19. Sex chromosome differentiation and the W- and Z-specific loci in Xenopus laevis.

    Science.gov (United States)

    Mawaribuchi, Shuuji; Takahashi, Shuji; Wada, Mikako; Uno, Yoshinobu; Matsuda, Yoichi; Kondo, Mariko; Fukui, Akimasa; Takamatsu, Nobuhiko; Taira, Masanori; Ito, Michihiko

    2017-06-15

    Genetic sex-determining systems in vertebrates include two basic types of heterogamety; XX (female)/XY (male) and ZZ (male)/ZW (female) types. The African clawed frog Xenopus laevis has a ZZ/ZW-type sex-determining system. In this species, we previously identified a W-specific sex (female)-determining gene dmw, and specified W and Z chromosomes, which could be morphologically indistinguishable (homomorphic). In addition to dmw, we most recently discovered two genes, named scanw and ccdc69w, and one gene, named capn5z in the W- and Z-specific regions, respectively. In this study, we revealed the detail structures of the W/Z-specific loci and genes. Sequence analysis indicated that there is almost no sequence similarity between 278kb W-specific and 83kb Z-specific sequences on chromosome 2Lq32-33, where both the transposable elements are abundant. Synteny and phylogenic analyses indicated that all the W/Z-specific genes might have emerged independently. Expression analysis demonstrated that scanw and ccdc69w or capn5z are expressed in early differentiating ZW gonads or testes, thereby suggesting possible roles in female or male development, respectively. Importantly, the sex-determining gene (SDG) dmw might have been generated after allotetraploidization, thereby indicating the construction of the new sex-determining system by dmw after species hybridization. Furthermore, by direct genotyping, we confirmed that diploid WW embryos developed into normal female frogs, which indicate that the Z-specific region is not essential for female development. Overall, these findings indicate that sex chromosome differentiation has started, although no heteromorphic sex chromosomes are evident yet, in X. laevis. Homologous recombination suppression might have promoted the accumulation of mutations and transposable elements, and enlarged the W/Z-specific regions, thereby resulting in differentiation of the W/Z chromosomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Influence of postzygotic reproductive isolation on the interspecific transmission of the paternal sex ratio chromosome in Trichogramma

    NARCIS (Netherlands)

    Jeong, G.S.; Stouthamer, R.

    2006-01-01

    The paternal sex ratio (PSR) chromosome is a supernumerary chromosome that causes the destruction of the paternal chromosome set in the first mitosis in a fertilized egg. It is known from parasitoid wasps in the genera Nasonia and Trichogramma (Hymenoptera). In these haplodiploids, the egg

  1. Sex differences in circadian food anticipatory activity are not altered by individual manipulations of sex hormones or sex chromosome copy number in mice.

    Science.gov (United States)

    Aguayo, Antonio; Martin, Camille S; Huddy, Timothy F; Ogawa-Okada, Maya; Adkins, Jamie L; Steele, Andrew D

    2018-01-01

    Recent studies in mice have demonstrated a sexual dimorphism in circadian entrainment to scheduled feeding. On a time restricted diet, males tend to develop food anticipatory activity (FAA) sooner than females and with a higher amplitude of activity. The underlying cause of this sex difference remains unknown. One study suggests that sex hormones, both androgens and estrogens, modulate food anticipatory activity in mice. Here we present results suggesting that the sex difference in FAA is unrelated to gonadal sex hormones. While a sex difference between males and females in FAA on a timed, calorie restricted diet was observed there were no differences between intact and gonadectomized mice in the onset or magnitude of FAA. To test other sources of the sex difference in circadian entrainment to scheduled feeding, we used sex chromosome copy number mutants, but there was no difference in FAA when comparing XX, XY-, XY-;Sry Tg, and XX;Sry Tg mice, demonstrating that gene dosage of sex chromosomes does not mediate the sex difference in FAA. Next, we masculinized female mice by treating them with 17-beta estradiol during the neonatal period; yet again, we saw no difference in FAA between control and masculinized females. Finally, we observed that there was no longer a sex difference in FAA for older mice, suggesting that the sex difference in FAA is age-dependent. Thus, our study demonstrates that singular manipulations of gonadal hormones, sex chromosomes, or developmental patterning are not able to explain the difference in FAA between young male and female mice.

  2. Sex Chromosome Evolution and Genomic Divergence in the Fish Hoplias malabaricus (Characiformes, Erythrinidae)

    Czech Academy of Sciences Publication Activity Database

    Sember, Alexandr; Bertollo, L.A.C.; Ráb, Petr; Yano, C. F.; Hatanaka, T.; de Oliveira, E. A.; de Bello Cioffi, M.

    2018-01-01

    Roč. 9, č. 1 (2018), č. článku 71. ISSN 1664-8021 R&D Projects: GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : fish cytogenetics * multiple sex chromosomes * sex-determining region Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 3.789, year: 2016

  3. Sex differences in life span: Females homozygous for the X chromosome do not suffer the shorter life span predicted by the unguarded X hypothesis.

    Science.gov (United States)

    Brengdahl, Martin; Kimber, Christopher M; Maguire-Baxter, Jack; Friberg, Urban

    2018-03-01

    Life span differs between the sexes in many species. Three hypotheses to explain this interesting pattern have been proposed, involving different drivers: sexual selection, asymmetrical inheritance of cytoplasmic genomes, and hemizygosity of the X(Z) chromosome (the unguarded X hypothesis). Of these, the unguarded X has received the least experimental attention. This hypothesis suggests that the heterogametic sex suffers a shortened life span because recessive deleterious alleles on its single X(Z) chromosome are expressed unconditionally. In Drosophila melanogaster, the X chromosome is unusually large (∼20% of the genome), providing a powerful model for evaluating theories involving the X. Here, we test the unguarded X hypothesis by forcing D. melanogaster females from a laboratory population to express recessive X-linked alleles to the same degree as males, using females exclusively made homozygous for the X chromosome. We find no evidence for reduced life span or egg-to-adult viability due to X homozygozity. In contrast, males and females homozygous for an autosome both suffer similar, significant reductions in those traits. The logic of the unguarded X hypothesis is indisputable, but our results suggest that the degree to which recessive deleterious X-linked alleles depress performance in the heterogametic sex appears too small to explain general sex differences in life span. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  4. Birth and death of genes linked to chromosomal inversion

    Science.gov (United States)

    Furuta, Yoshikazu; Kawai, Mikihiko; Yahara, Koji; Takahashi, Noriko; Handa, Naofumi; Tsuru, Takeshi; Oshima, Kenshiro; Yoshida, Masaru; Azuma, Takeshi; Hattori, Masahira; Uchiyama, Ikuo; Kobayashi, Ichizo

    2011-01-01

    The birth and death of genes is central to adaptive evolution, yet the underlying genome dynamics remain elusive. The availability of closely related complete genome sequences helps to follow changes in gene contents and clarify their relationship to overall genome organization. Helicobacter pylori, bacteria in our stomach, are known for their extreme genome plasticity through mutation and recombination and will make a good target for such an analysis. In comparing their complete genome sequences, we found that gain and loss of genes (loci) for outer membrane proteins, which mediate host interaction, occurred at breakpoints of chromosomal inversions. Sequence comparison there revealed a unique mechanism of DNA duplication: DNA duplication associated with inversion. In this process, a DNA segment at one chromosomal locus is copied and inserted, in an inverted orientation, into a distant locus on the same chromosome, while the entire region between these two loci is also inverted. Recognition of this and three more inversion modes, which occur through reciprocal recombination between long or short sequence similarity or adjacent to a mobile element, allowed reconstruction of synteny evolution through inversion events in this species. These results will guide the interpretation of extensive DNA sequencing results for understanding long- and short-term genome evolution in various organisms and in cancer cells. PMID:21212362

  5. First Description of the Karyotype and Sex Chromosomes in the Komodo Dragon (Varanus komodoensis)

    Czech Academy of Sciences Publication Activity Database

    Johnson Pokorná, Martina; Altmanová, M.; Rovatsos, M.; Velenský, P.; Vodička, R.; Řehák, I.; Kratochvíl, L.

    2016-01-01

    Roč. 148, č. 4 (2016), s. 284-291 ISSN 1424-8581 Institutional support: RVO:67985904 Keywords : CGH * female heterogamety * heterochromatin * microsatellite accumulation * sex chromosome evolution * squamate reptile Subject RIV: EG - Zoology Impact factor: 1.354, year: 2016

  6. The paternal-sex-ratio (PSR) chromosome in natural populations of Nasonia (Hymenoptera Chalcidoidea)

    NARCIS (Netherlands)

    Beukeboom, L.W.; Werren, J.H.

    2000-01-01

    Selfish genetic elements may be important in promoting evolutionary change. Paternal sex ratio (PSR) is a selfish B chromosome that causes all-male families in the haplodiploid parasitic wasp Nasonia vitripennis, by inducing paternal genome loss in fertilized eggs. The natural distribution and

  7. Sex-chromosome heterochromatin variation in the wood mouse, Apodemus sylvaticus

    Czech Academy of Sciences Publication Activity Database

    Nová, P.; Reutter, B. A.; Rábová, Marie; Zima, Jan

    2002-01-01

    Roč. 96, 1-4 (2002), s. 186-190 ISSN 0301-0171 R&D Projects: GA AV ČR KSK6005114 Keywords : sex-chromosome * Apodemus sylvaticus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.114, year: 2002

  8. Vocal and Gestural Productions of 24-Month-Old Children with Sex Chromosome Trisomies

    Science.gov (United States)

    Zampini, Laura; Draghi, Lara; Silibello, Gaia; Dall'Ara, Francesca; Rigamonti, Claudia; Suttora, Chiara; Zanchi, Paola; Salerni, Nicoletta; Lalatta, Faustina; Vizziello, Paola

    2018-01-01

    Background: Children with sex chromosome trisomies (SCT) frequently show problems in language development. However, a clear description of the communicative patterns of these children is still lacking. Aims: To describe the first stages of language development in children with SCT in comparison with those in typically developing (TD) children. The…

  9. Multiple sex chromosomes in the light of female meiotic drive in amniote vertebrates

    Czech Academy of Sciences Publication Activity Database

    Pokorná, Martina; Altmanová, M.; Kratochvíl, L.

    2014-01-01

    Roč. 22, č. 1 (2014), s. 35-44 ISSN 0967-3849 R&D Projects: GA ČR GAP506/10/0718 Institutional support: RVO:67985904 Keywords : amniota * centromere * heterogamety * neo-sex chromosomes * reptiles Subject RIV: EG - Zoology Impact factor: 2.478, year: 2014

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

    DEFF Research Database (Denmark)

    Boyd, Patricia Anne; Loane, Maria; Garne, Ester

    2011-01-01

    This study aims to assess prevalence and pregnancy outcome for sex chromosome trisomies (SCTs) diagnosed prenatally or in the first year of life. Data held by the European Surveillance of Congenital Anomalies (EUROCAT) database on SCT cases delivered 2000-2005 from 19 population-based registries ...

  11. Empirical evidence for large X-effects in animals with undifferentiated sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Dufresnes, C.; Majtyka, T.; Baird, Stuart J. E.; Gerchen, J. F.; Borzée, A.; Savary, R.; Ogielska, M.; Perrin, N.; Stöck, M.

    2016-01-01

    Roč. 6, č. 21029 (2016), s. 21029 ISSN 2045-2322 Institutional support: RVO:68081766 Keywords : controlled study * genetic marker * hybrid zone * Hyla * introgression * sex chromosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.259, year: 2016

  12. Nuclear organization in human sperm: preliminary evidence for altered sex chromosome centromere position in infertile males.

    Science.gov (United States)

    Finch, K A; Fonseka, K G L; Abogrein, A; Ioannou, D; Handyside, A H; Thornhill, A R; Hickson, N; Griffin, D K

    2008-06-01

    Many genetic defects with a chromosomal basis affect male reproduction via a range of different mechanisms. Chromosome position is a well-known marker of nuclear organization, and alterations in standard patterns can lead to disease phenotypes such as cancer, laminopathies and epilepsy. It has been demonstrated that normal mammalian sperm adopt a pattern with the centromeres aligning towards the nuclear centre. The purpose of this study was to test the hypothesis that altered chromosome position in the sperm head is associated with male infertility. The average nuclear positions of fluorescence in-situ hybridization signals for three centromeric probes (for chromosomes X, Y and 18) were compared in normoozoospermic men and in men with compromised semen parameters. In controls, the centromeres of chromosomes X, Y and 18 all occupied a central nuclear location. In infertile men the sex chromosomes appeared more likely to be distributed in a pattern not distinguishable from a random model. Our findings cast doubt on the reliability of centromeric probes for aneuploidy screening. The analysis of chromosome position in sperm heads should be further investigated for the screening of infertile men.

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

    Directory of Open Access Journals (Sweden)

    Teruko Taketo

    2015-06-01

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

  14. Unusual arrangement and behaviour of the sex chromosomes of Aphodius (Agolius abdominalis Bonelli, 1812, and comparison with A. (A. bonvouloiri Harold, 1860 (Coleoptera: Aphodiidae

    Directory of Open Access Journals (Sweden)

    Robert Angus

    2009-12-01

    Full Text Available Aphodius abdominalis Bonelli, 1812 is shown to have a karyotype comprising nine pairs of autosomes and sex chromosomes which are X0 (male, XX (female. At first metaphase of meiosis the X chromosome is linked to an autosomal bivalent by a darkly staining area of the cytoplasm, resembling the Xy p arrangement typical of Aphodius species, but giving nine, rather than 10, elements in the nucleus. C-banding, which shows the centromeres, confirms this unusual arrangement. A. bonvouloiri, the only other known species of subgenus Agolius Mulsant et Rey, 1869, has a male karyotype with nine pairs of autosomes and Xy sex chromosomes. No preparations of its meiosis are available.

  15. Human sperm sex chromosome disomy and sperm DNA damage assessed by the neutral comet assay.

    Science.gov (United States)

    McAuliffe, M E; Williams, P L; Korrick, S A; Dadd, R; Marchetti, F; Martenies, S E; Perry, M J

    2014-10-10

    Is there an association between human sperm sex chromosome disomy and sperm DNA damage? An increase in human sperm XY disomy was associated with higher comet extent; however, there was no other consistent association of sex chromosome disomies with DNA damage. There is limited published research on the association between sex chromosome disomy and sperm DNA damage and the findings are not consistent across studies. We conducted a cross-sectional study of 190 men (25% ever smoker, 75% never smoker) from subfertile couples presenting at the Massachusetts General Hospital Fertility Clinic from January 2000 to May 2003. Multiprobe fluorescence in situ hybridization for chromosomes X, Y and 18 was used to determine XX, YY, XY and total sex chromosome disomy in sperm nuclei using an automated scoring method. The neutral comet assay was used to measure sperm DNA damage, as reflected by comet extent, percentage DNA in the comet tail, and tail distributed moment. Univariate and multiple linear regression models were constructed with sex chromosome disomy (separate models for each of the four disomic conditions) as the independent variable, and DNA damage parameters (separate models for each measure of DNA damage) as the dependent variable. Men with current or past smoking history had significantly greater comet extent (µm: regression coefficients with 95% CI) [XX18: 15.17 (1.98, 28.36); YY18: 14.68 (1.50, 27.86); XY18: 15.41 (2.37, 28.45); Total Sex Chromosome Disomy: 15.23 (2.09, 28.38)], and tail distributed moment [XX18: 3.01 (0.30, 5.72); YY18: 2.95 (0.24, 5.67); XY18: 3.04 (0.36, 5.72); Total Sex Chromosome Disomy: 3.10 (0.31, 5.71)] than men who had never smoked. In regression models adjusted for age and smoking, there was a positive association between XY disomy and comet extent. For an increase in XY disomy from 0.56 to 1.47% (representing the 25th to 75th percentile), there was a mean increase of 5.08 µm in comet extent. No other statistically significant

  16. Sexual dimorphism in mammalian autosomal gene regulation is determined not only by Sry but by sex chromosome complement as well.

    Science.gov (United States)

    Wijchers, Patrick J; Yandim, Cihangir; Panousopoulou, Eleni; Ahmad, Mushfika; Harker, Nicky; Saveliev, Alexander; Burgoyne, Paul S; Festenstein, Richard

    2010-09-14

    Differences between males and females are normally attributed to developmental and hormonal differences between the sexes. Here, we demonstrate differences between males and females in gene silencing using a heterochromatin-sensitive reporter gene. Using "sex-reversal" mouse models with varying sex chromosome complements, we found that this differential gene silencing was determined by X chromosome complement, rather than sex. Genome-wide transcription profiling showed that the expression of hundreds of autosomal genes was also sensitive to sex chromosome complement. These genome-wide analyses also uncovered a role for Sry in modulating autosomal gene expression in a sex chromosome complement-specific manner. The identification of this additional layer in the establishment of sexual dimorphisms has implications for understanding sexual dimorphisms in physiology and disease. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. Environmental Exposure of Sperm Sex-Chromosomes: A Gender Selection Technique.

    Science.gov (United States)

    Oyeyipo, Ibukun P; van der Linde, Michelle; du Plessis, Stefan S

    2017-10-01

    Preconceptual sex selection is still a highly debatable process whereby X- and Y-chromosome-bearing spermatozoa are isolated prior to fertilization of the oocyte. Although various separation techniques are available, none can guarantee 100% accuracy. The aim of this study was to separate X- and Y-chromosome-bearing spermatozoa using methods based on the viability difference between the X- and Y-chromosome-bearing spermatozoa. A total of 18 experimental semen samples were used, written consent was obtained from all donors and results were analysed in a blinded fashion. Spermatozoa were exposed to different pH values (5.5, 6.5, 7.5, 8.5, and 9.5), increased temperatures (37°C, 41°C, and 45°C) and ROS level (50 μM, 750 μM, and 1,000 μM). The live and dead cell separation was done through a modified swim-up technique. Changes in the sex-chromosome ratio of samples were established by double-label fluorescent in situ hybridization (FISH) before and after processing. The results indicated successful enrichment of Xchromosome-bearing spermatozoa upon incubation in acidic media, increased temperatures, and elevated H 2 O 2 . This study demonstrated the potential role for exploring the physiological differences between X-and Y-chromosome-bearing spermatozoa in the development of preconceptual gender selection.

  18. Klinefelter syndrome comorbidities linked to increased X chromosome gene dosage and altered protein interactome activity

    DEFF Research Database (Denmark)

    Belling, Kirstine González-Izarzugaza; Russo, Francesco; Jensen, Anders Boeck

    2017-01-01

    Klinefelter syndrome (KS) (47,XXY) is the most common male sex chromosome aneuploidy. Diagnosis and clinical supervision remain a challenge due to varying phenotypic presentation and insufficient characterization of the syndrome. Here we combine health data-driven epidemiology and molecular level...

  19. Sex, rebellion and decadence: the scandalous evolutionary history of the human Y chromosome.

    Science.gov (United States)

    Navarro-Costa, Paulo

    2012-12-01

    It can be argued that the Y chromosome brings some of the spirit of rock&roll to our genome. Equal parts degenerate and sex-driven, the Y has boldly rebelled against sexual recombination, one of the sacred pillars of evolution. In evolutionary terms this chromosome also seems to have adopted another of rock&roll's mottos: living fast. Yet, it appears to have refused to die young. In this manuscript the Y chromosome will be analyzed from the intersection between structural, evolutionary and functional biology. Such integrative approach will present the Y as a highly specialized product of a series of remarkable evolutionary processes. These led to the establishment of a sex-specific genomic niche that is maintained by a complex balance between selective pressure and the genetic diversity introduced by intrachromosomal recombination. Central to this equilibrium is the "polish or perish" dilemma faced by the male-specific Y genes: either they are polished by the acquisition of male-related functions or they perish via the accumulation of inactivating mutations. Thus, understanding to what extent the idiosyncrasies of Y recombination may impact this chromosome's role in sex determination and male germline functions should be regarded as essential for added clinical insight into several male infertility phenotypes. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. A Role for the X Chromosome in Sex Differences in Variability in General Intelligence?

    Science.gov (United States)

    Johnson, Wendy; Carothers, Andrew; Deary, Ian J

    2009-11-01

    There is substantial evidence that males are more variable than females in general intelligence. In recent years, researchers have presented this as a reason that, although there is little, if any, mean sex difference in general intelligence, males tend to be overrepresented at both ends of its overall distribution. Part of the explanation could be the presence of genes on the X chromosome related both to syndromal disorders involving mental retardation and to population variation in general intelligence occurring normally. Genes on the X chromosome appear overrepresented among genes with known involvement in mental retardation, which is consistent with a model we developed of the population distribution of general intelligence as a mixture of two normal distributions. Using this model, we explored the expected ratios of males to females at various points in the distribution and estimated the proportion of variance in general intelligence potentially due to genes on the X chromosome. These estimates provide clues to the extent to which biologically based sex differences could be manifested in the environment as sex differences in displayed intellectual abilities. We discuss these observations in the context of sex differences in specific cognitive abilities and evolutionary theories of sexual selection. © 2009 Association for Psychological Science.

  1. Histone H2AFX Links Meiotic Chromosome Asynapsis to Prophase I Oocyte Loss in Mammals.

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    Jeffrey M Cloutier

    2015-10-01

    Full Text Available Chromosome abnormalities are common in the human population, causing germ cell loss at meiotic prophase I and infertility. The mechanisms driving this loss are unknown, but persistent meiotic DNA damage and asynapsis may be triggers. Here we investigate the contribution of these lesions to oocyte elimination in mice with chromosome abnormalities, e.g. Turner syndrome (XO and translocations. We show that asynapsed chromosomes trigger oocyte elimination at diplonema, which is linked to the presence of phosphorylated H2AFX (γH2AFX. We find that DNA double-strand break (DSB foci disappear on asynapsed chromosomes during pachynema, excluding persistent DNA damage as a likely cause, and demonstrating the existence in mammalian oocytes of a repair pathway for asynapsis-associated DNA DSBs. Importantly, deletion or point mutation of H2afx restores oocyte numbers in XO females to wild type (XX levels. Unexpectedly, we find that asynapsed supernumerary chromosomes do not elicit prophase I loss, despite being enriched for γH2AFX and other checkpoint proteins. These results suggest that oocyte loss cannot be explained simply by asynapsis checkpoint models, but is related to the gene content of asynapsed chromosomes. A similar mechanistic basis for oocyte loss may operate in humans with chromosome abnormalities.

  2. Histone H2AFX Links Meiotic Chromosome Asynapsis to Prophase I Oocyte Loss in Mammals

    Science.gov (United States)

    Cloutier, Jeffrey M.; Mahadevaiah, Shantha K.; ElInati, Elias; Nussenzweig, André; Tóth, Attila; Turner, James M. A.

    2015-01-01

    Chromosome abnormalities are common in the human population, causing germ cell loss at meiotic prophase I and infertility. The mechanisms driving this loss are unknown, but persistent meiotic DNA damage and asynapsis may be triggers. Here we investigate the contribution of these lesions to oocyte elimination in mice with chromosome abnormalities, e.g. Turner syndrome (XO) and translocations. We show that asynapsed chromosomes trigger oocyte elimination at diplonema, which is linked to the presence of phosphorylated H2AFX (γH2AFX). We find that DNA double-strand break (DSB) foci disappear on asynapsed chromosomes during pachynema, excluding persistent DNA damage as a likely cause, and demonstrating the existence in mammalian oocytes of a repair pathway for asynapsis-associated DNA DSBs. Importantly, deletion or point mutation of H2afx restores oocyte numbers in XO females to wild type (XX) levels. Unexpectedly, we find that asynapsed supernumerary chromosomes do not elicit prophase I loss, despite being enriched for γH2AFX and other checkpoint proteins. These results suggest that oocyte loss cannot be explained simply by asynapsis checkpoint models, but is related to the gene content of asynapsed chromosomes. A similar mechanistic basis for oocyte loss may operate in humans with chromosome abnormalities. PMID:26509888

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

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    Hager Karl

    2012-04-01

    Full Text Available Abstract 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.

  4. Identification of the sex-determining locus in grass puffer (Takifugu niphobles) provides evidence for sex-chromosome turnover in a subset of Takifugu species

    Science.gov (United States)

    Atsumi, Kazufumi; Kamiya, Takashi; Nozawa, Aoi; Aoki, Yuma; Tasumi, Satoshi; Koyama, Takashi; Nakamura, Osamu; Suzuki, Yuzuru

    2018-01-01

    There is increasing evidence for frequent turnover in sex chromosomes in vertebrates. Yet experimental systems suitable for tracing the detailed process of turnover are rare. In theory, homologous turnover is possible if the new sex-determining locus is established on the existing sex-chromosome. However, there is no empirical evidence for such an event. The genus Takifugu includes fugu (Takifugu rubripes) and its two closely-related species whose sex is most likely determined by a SNP at the Amhr2 locus. In these species, males are heterozygous, with G and C alleles at the SNP site, while females are homozygous for the C allele. To determine if a shift in the sex-determining locus occurred in another member of this genus, we used genetic mapping to characterize the sex-chromosome systems of Takifugu niphobles. We found that the G allele of Amhr2 is absent in T. niphobles. Nevertheless, our initial mapping suggests a linkage between the phenotypic sex and the chromosome 19, which harbors the Amhr2 locus. Subsequent high-resolution analysis using a sex-reversed fish demonstrated that the sex-determining locus maps to the proximal end of chromosome 19, far from the Amhr2 locus. Thus, it is likely that homologous turnover involving these species has occurred. The data also showed that there is a male-specific reduction of recombination around the sex-determining locus. Nevertheless, no evidence for sex-chromosome differentiation was detected: the reduced recombination depended on phenotypic sex rather than genotypic sex; no X- or Y-specific maker was obtained; the YY individual was viable. Furthermore, fine-scale mapping narrowed down the new sex-determining locus to the interval corresponding to approximately 300-kb of sequence in the fugu genome. Thus, T. niphobles is determined to have a young and small sex-determining region that is suitable for studying an early phase of sex-chromosome evolution and the mechanisms underlying turnover of sex chromosome. PMID

  5. Molecular cytogenetic analysis of monoecious hemp (Cannabis sativa L.) cultivars reveals its karyotype variations and sex chromosomes constitution.

    Science.gov (United States)

    Razumova, Olga V; Alexandrov, Oleg S; Divashuk, Mikhail G; Sukhorada, Tatiana I; Karlov, Gennady I

    2016-05-01

    Hemp (Cannabis sativa L., 2n = 20) is a dioecious plant. Sex expression is controlled by an X-to-autosome balance system consisting of the heteromorphic sex chromosomes XY for males and XX for females. Genetically monoecious hemp offers several agronomic advantages compared to the dioecious cultivars that are widely used in hemp cultivation. The male or female origin of monoecious maternal plants is unknown. Additionally, the sex chromosome composition of monoecious hemp forms remains unknown. In this study, we examine the sex chromosome makeup in monoecious hemp using a cytogenetic approach. Eight monoecious and two dioecious cultivars were used. The DNA of 210 monoecious plants was used for PCR analysis with the male-associated markers MADC2 and SCAR323. All monoecious plants showed female amplification patterns. Fluorescence in situ hybridization (FISH) with the subtelomeric CS-1 probe to chromosomes plates and karyotyping revealed a lack of Y chromosome and presence of XX sex chromosomes in monoecious cultivars with the chromosome number 2n = 20. There was a high level of intra- and intercultivar karyotype variation detected. The results of this study can be used for further analysis of the genetic basis of sex expression in plants.

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

    Science.gov (United States)

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

    2009-01-01

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

  7. Fetal sex determination in the first trimester of pregnancy using a Y chromosome-specific DNA probe

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Y.; Huang, S.; Chen, M.; Huang, Y.; Zhang, M.; Dong, J.; Ku, A.; Xu, S.

    1987-05-01

    Prenatal determination of fetal sex is important for the prevention of X-linked disorders such as hemophilia, Lesch-Nyhan syndrome and Duchenne muscular dystrophy. The complex procedures of prenatal diagnosis for X-linked disorders are unnecessary if the fetus is female, because usually no clinical symptoms ever appear in female. pY 3.4 probe used in this work for sex determination is a 3.4 kilobase human repeat sequence. The probe is specific for the Y chromosome of males and can be used for sex determination. The other prove pBLUR used in this paper as control is a widely dispersed, highly repeated human Alu family DNA sequence, represented equally in male and female DNA. On the basis of the relative densities of the autoradiographic spots produced by hybridization of fetal DNA with pY3.4 and pBLUR, the sex of fetus can be clearly identified. Further the authors can determine the radioactive intensity (cpm) of the hybridized DNA spots and the ratio of hybridization with Y3.4 to pBLUR (Y3.4/pBLUR x 10). Results show that the hybridization ratio of DNA from chorionic villi of male (1.03 +/- 0.24) is significantly higher than that of female (0.16 +/- 0.09). Therefore, sex determination of the fetus can be made, based on the ratio of pY3.4/pBLUR x 10. If necessary they can also use Southern hybridization with pY 3.4 probe of DNA isolated from chorionic villi to confirm the result of dot hybridization.

  8. Heterochromatin position effects on circularized sex chromosomes cause filicidal embryonic lethality in Drosophila melanogaster.

    Science.gov (United States)

    Ferree, Patrick M; Gomez, Karina; Rominger, Peter; Howard, Dagnie; Kornfeld, Hannah; Barbash, Daniel A

    2014-04-01

    Some circularized X-Y chromosomes in Drosophila melanogaster are mitotically unstable and induce early embryonic lethality, but the genetic basis is unknown. Our experiments suggest that a large region of X-linked satellite DNA causes anaphase bridges and lethality when placed into a new heterochromatic environment within certain circularized X-Y chromosomes. These results reveal that repetitive sequences can be incompatible with one another in cis. The lethal phenotype also bears a remarkable resemblance to a case of interspecific hybrid lethality.

  9. The origin of a selfish B chromosome triggering paternal sex ratio in the parasitoid wasp Trichogramma kaykai

    NARCIS (Netherlands)

    Vugt, van J.J.F.A.; Jong, de J.H.S.G.M.; Stouthamer, R.

    2009-01-01

    This study uses molecular and cytogenetic methods to determine the origin of a B chromosome in some males of the wasp Trichogramma kaykai. This so-called paternal sex ratio (PSR) chromosome transmits only through sperm and shortly after fertilization triggers degeneration of the paternal genome,

  10. Genetics, chromatin diminution, and sex chromosome evolution in the parasitic nematode genus Strongyloides.

    Science.gov (United States)

    Nemetschke, Linda; Eberhardt, Alexander G; Hertzberg, Hubertus; Streit, Adrian

    2010-10-12

    When chromatin diminution occurs during a cell division a portion of the chromatin is eliminated, resulting in daughter cells with a smaller amount of genetic material. In the parasitic roundworms Ascaris and Parascaris, chromatin diminution creates a genetic difference between the soma and the germline. However, the function of chromatin diminution remains a mystery, because the vast majority of the eliminated DNA is noncoding. Within the parasitic roundworm genus Strongyloides, S. stercoralis (in man) and S. ratti (in rat) employ XX/XO sex determination, but the situation in S. papillosus (in sheep) is different but controversial. We demonstrate genetically that S. papillosus employs sex-specific chromatin diminution to eliminate an internal portion of one of the two homologs of one chromosome pair in males. Contrary to ascarids, the eliminated DNA in S. papillosus contains a large number of genes. We demonstrate that the region undergoing diminution is homologous to the X chromosome of the closely related S. ratti. The flanking regions, which are not diminished, are homologous to the S. ratti autosome number I. Furthermore, we found that the diminished chromosome is not incorporated into sperm, resulting in a male-specific transmission ratio distortion. Our data indicate that on the evolutionary path to S. papillosus, the X chromosome fused with an autosome. Chromatin diminution serves to functionally restore an XX/XO sex-determining system. A consequence of the fusion and the process that copes with it is a transmission ratio distortion in males for certain loci. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Sex linked recessive dystonia parkinsonism of Panay, Philippines (XDP).

    Science.gov (United States)

    Lee, L V; Munoz, E L; Tan, K T; Reyes, M T

    2001-12-01

    Sex linked dystonia parkinsonism (XDP), also referred to as "lubag" in American literature, was described in 1975 occurring endemically in Panay, Philippines. It is an adult onset, sex linked, predominantly male, severe, progressive movement disorder with high penetrance and a high frequency of generalisation. The movement disorder is characterised by dystonic movements, usually starting in the 3rd or 4th decade, spreading to generalisation within two to five years. The dystonia coexists or is replaced by parkinsonism usually beyond the 10th year of illness. No treatment has been found to be effective. Neuroimaging shows caudate and putamenal atrophy in patients reaching the parkinsonian stage. Neuropathology reveals pronounced atrophy of the caudate and putamen, mostly in the cases with long standing illness. The sex linked pattern of inheritance has been established. Genetic studies have located the affected gene (DYT3) to Xq13.1, with one group mapping the XDP gene to a < 350 kb locus in the DXS 7117-DXS 559 region.

  12. Sex-linked pheromone receptor genes of the European corn borer, Ostrinia nubilalis, are in tandem arrays.

    Directory of Open Access Journals (Sweden)

    Yuji Yasukochi

    Full Text Available BACKGROUND: Tuning of the olfactory system of male moths to conspecific female sex pheromones is crucial for correct species recognition; however, little is known about the genetic changes that drive speciation in this system. Moths of the genus Ostrinia are good models to elucidate this question, since significant differences in pheromone blends are observed within and among species. Odorant receptors (ORs play a critical role in recognition of female sex pheromones; eight types of OR genes expressed in male antennae were previously reported in Ostrinia moths. METHODOLOGY/PRINCIPAL FINDINGS: We screened an O. nubilalis bacterial artificial chromosome (BAC library by PCR, and constructed three contigs from isolated clones containing the reported OR genes. Fluorescence in situ hybridization (FISH analysis using these clones as probes demonstrated that the largest contig, which contained eight OR genes, was located on the Z chromosome; two others harboring two and one OR genes were found on two autosomes. Sequence determination of BAC clones revealed the Z-linked OR genes were closely related and tandemly arrayed; moreover, four of them shared 181-bp direct repeats spanning exon 7 and intron 7. CONCLUSIONS/SIGNIFICANCE: This is the first report of tandemly arrayed sex pheromone receptor genes in Lepidoptera. The localization of an OR gene cluster on the Z chromosome agrees with previous findings for a Z-linked locus responsible for O. nubilalis male behavioral response to sex pheromone. The 181-bp direct repeats might enhance gene duplications by unequal crossovers. An autosomal locus responsible for male response to sex pheromone in Heliothis virescens and H. subflexa was recently reported to contain at least four OR genes. Taken together, these findings support the hypothesis that generation of additional copies of OR genes can increase the potential for male moths to acquire altered specificity for pheromone components, and accordingly

  13. X-linked gene expression and X-chromosome inactivation: marsupials, mouse, and man compared.

    Science.gov (United States)

    VandeBerg, J L; Robinson, E S; Samollow, P B; Johnston, P G

    1987-01-01

    The existence of paternal X inactivation in Australian and American marsupial species suggests that this feature of X-chromosome dosage compensation is not a recent adaptation, but probably predates the evolutionary separation of the Australian and American marsupial lineages. Although it is theoretically possible that the marsupial system is one of random X inactivation with p greater than 0.99 and q less than 0.01 and dependent on parental source, no instance of random X inactivation (p = q or p not equal to q) has ever been verified in any tissue or cell type of any marsupial species. Therefore, we conclude that the most fundamental difference in X inactivation of marsupials and eutherians is whether the inactive X is the paternal one or is determined at random (with p = q in most but not all cases). The only other unequivocal difference between eutherians and marsupials is that both X chromosomes are active in mice and human oocytes, but not in kangaroo oocytes. Apparently, the inactive X is reactivated at a later meiotic stage or during early embryogenesis in kangaroos. X-chromosome inactivation takes place early in embryogenesis of eutherians and marsupials. Extraembryonic membranes of mice exhibit paternal X inactivation, whereas those of humans seem to exhibit random X inactivation with p greater than q (i.e., preferential paternal X inactivation). In general, extraembryonic membranes of marsupial exhibit paternal X inactivation, but the Gpd locus is active on both X chromosomes in at least some cells of kangaroo yolk sac. It is difficult to draw any general conclusion because of major differences in embryogeny of mice, humans, and marsupials, and uncertainties in interpreting the data from humans. Other differences between marsupials and eutherians in patterns of X-linked gene expression and X-chromosome inactivation seem to be quantitative rather than qualitative. Partial expression of some genes on the inactive X is characteristic of marsupials, with

  14. [Familial febrile convulsions is supposed to link to human chromosome 19p13.3].

    Science.gov (United States)

    Qi, Y; Lü, J; Wu, X

    2001-01-10

    To localize the familial febrile convulsion (FC) genes on human chromosomes. For 63 FC pedigrees, tetranucleotide repeat markers D19S253 D19S395 and D19S591 on the short arm of chromosome 19, as well as dinucleotide repeat markers D8S84 and D8S85 on the long arm of chromosome 8 were genotyped. Transmission disequilibrium test (TDT) and Lod score calculation were carried out. The data were processed by PPAP software package. All the alleles in every locus of FC probands and normal controls were in Hardy-Weinburg balance. Transmission disequilibrium was found on D8S84, D19S395 and D19S591 in FC families. chi(2) values were 4.0, 5.124 and 7.364 separately. Each P value was < 0.05, and significantly meaningful. The two-point Lod scores between D8S84 and FC, D8S85 and FC, D19S253 and FC, D19S395 and FC, D19S591 and FC are 0.00002, 0.000017, 0.58, 1.53 and 1.42 respectively. The multi-point Lod score among markers on chromosome 8q and FC was 0.88, while Lod score among markers on chromosome 19p and FC reached 2.78. The results by both the non-parameter (TDT) and parameter (Lod score) methods were consistant on a whole. FC is linked with chromosome region 19p13.3, but not with chromosome 8q.

  15. Identification of a Novel Retrotransposon with Sex Chromosome-Specific Distribution in Silene latifolia

    Czech Academy of Sciences Publication Activity Database

    Králová, Tereza; Čegan, Radim; Kubát, Zdeněk; Vrána, Jan; Vyskot, Boris; Vogel, Ivan; Kejnovský, Eduard; Hobza, Roman

    2014-01-01

    Roč. 143, 1-3 (2014), s. 87-95 ISSN 1424-8581 R&D Projects: GA MŠk(CZ) LM2010005; GA ČR(CZ) GAP501/10/0102; GA ČR(CZ) GAP501/12/2220; GA ČR(CZ) GAP305/10/0930; GA ČR(CZ) GA522/09/0083; GA MŠk(CZ) LO1204 Institutional support: RVO:68081707 Keywords : Microdissection * Sex chromosomes * Silene latifolia (white campion) Subject RIV: BO - Biophysics; EF - Botanics (UEB-Q) Impact factor: 1.561, year: 2014

  16. Tebufenozide resistance is associated with sex-linked inheritance in Plutella xylostella.

    Science.gov (United States)

    Cao, Guang-Chun; Han, Zhao-Jun

    2015-04-01

    The diamondback moth (DBM), Plutella xylostella (L.), is a major pest of cruciferous crops. Tebufenozide, a novel nonsteroidal ecdysone agonist, exhibits good efficacy and has played an increasingly important role in the control of Lepidopteran pests in China. For its resistance management, the genetic basis of tebufenozide resistance was studied using a laboratory selected resistant strain of DBM (resistant ratio, RR = 268). A series of crosses with laboratory susceptible and resistant strains revealed that tebufenozide resistance in this pest was partially biased toward female heredity, with a large difference in RR for F1 (RR = 29) and rF1 progeny (RR = 147). The dominance calculated for these 2 cross progeny was -0.788 and 0.09, respectively. Further analysis showed that the susceptible male and female larvae were similar in their sensitivity to tebufenozide, but the resistant female larvae showed significantly higher resistance than the resistant male larvae. The heredity of tebufenozide resistance in DBM might be linked with the W sex chromosome, which suggested that DBM has the ability to develop high levels of resistance to tebufenozide. This is the first report of sex-linked inheritance of tebufenozide resistance in P. xylostella (L.). © 2013 Institute of Zoology, Chinese Academy of Sciences.

  17. XY sex chromosome complement, compared with XX, in the CNS confers greater neurodegeneration during experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Du, Sienmi; Itoh, Noriko; Askarinam, Sahar; Hill, Haley; Arnold, Arthur P; Voskuhl, Rhonda R

    2014-02-18

    Women are more susceptible to multiple sclerosis (MS) and have more robust immune responses than men. However, men with MS tend to demonstrate a more progressive disease course than women, suggesting a disconnect between the severity of an immune attack and the CNS response to a given immune attack. We have previously shown in an MS model, experimental autoimmune encephalomyelitis, that autoantigen-sensitized XX lymph node cells, compared with XY, are more encephalitogenic. These studies demonstrated an effect of sex chromosomes in the induction of immune responses, but did not address a potential role of sex chromosomes in the CNS response to immune-mediated injury. Here, we examined this possibility using XX versus XY bone marrow chimeras reconstituted with a common immune system of one sex chromosomal type. We found that experimental autoimmune encephalomyelitis mice with an XY sex chromosome complement in the CNS, compared with XX, demonstrated greater clinical disease severity with more neuropathology in the spinal cord, cerebellum, and cerebral cortex. A candidate gene on the X chromosome, toll-like receptor 7, was then examined. Toll-like receptor 7 expression in cortical neurons was higher in mice with XY compared with mice with XX CNS, consistent with the known neurodegenerative role for toll-like receptor 7 in neurons. These results suggest that sex chromosome effects on neurodegeneration in the CNS run counter to effects on immune responses, and may bear relevance to the clinical enigma of greater MS susceptibility in women but faster disability progression in men. This is a demonstration of a direct effect of sex chromosome complement on neurodegeneration in a neurological disease.

  18. X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus

    Directory of Open Access Journals (Sweden)

    Adauto Lima Cardoso

    2015-06-01

    Full Text Available Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B . n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes.

  19. Resolution and evolution of the duck-billed platypus karyotype with an X1Y1X2Y2X3Y3X4Y4X5Y5 male sex chromosome constitution.

    Science.gov (United States)

    Rens, Willem; Grützner, Frank; O'brien, Patricia C M; Fairclough, Helen; Graves, Jennifer A M; Ferguson-Smith, Malcolm A

    2004-11-16

    The platypus (2n = 52) has a complex karyotype that has been controversial over the last three decades. The presence of unpaired chromosomes and an unknown sex-determining system especially has defied attempts at conventional analysis. This article reports on the preparation of chromosome-specific probes from flow-sorted chromosomes and their application in the identification and classification of all platypus chromosomes. This work reveals that the male karyotype has 21 pairs of chromosomes and 10 unpaired chromosomes (E1-E10), which are linked by short regions of homology to form a multivalent chain in meiosis. The female karyotype differs in that five of these unpaired elements (E1, E3, E5, E7, and E9) are each present in duplicate, whereas the remaining five unpaired elements (E2, E4, E6, E8, and E10) are absent. This finding indicates that sex is determined by the alternate segregation of the chain of 10 during spermatogenesis so that equal numbers of sperm bear either one of the two groups of five elements, i.e., five X and five Y chromosomes. Chromosome painting reveals that these X and Y chromosomes contain pairing (XY shared) and differential (X- or Y-specific) segments. Y differential regions must contain male-determining genes, and X differential regions should be dosage-compensated in the female. Two models for the evolution of the sex-determining system are presented. The resolution of the longstanding debate over the platypus karyotype is an important step toward the understanding of mechanisms of sex determination, dosage compensation, and karyotype evolution.

  20. Polytene chromosome analysis in relation to genetic sex separation in the Mediterranean fruit fly, Ceratitis capitata (Wied.)

    International Nuclear Information System (INIS)

    Kerremans, P.; Busch-Petersen, E.

    1990-01-01

    The development of stable genetic sexing strains in the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann), is hampered by the presence of low levels of male recombination. Such recombination may be reduced by minimizing the distance between the translocation breakpoint and the translocated 'sexing' allele. Cytogenetic analysis of mitotic/meiotic and polytene chromosomes could provide information on the selection of such potentially stable genetic sexing strains. Translocation breakpoints in two genetic sexing strains in the medfly, based on a white female/brown male pupal colour dimorphism, have been determined. Preliminary results are described and the advantages and limitations of polytene chromosome analysis for the isolation of stable genetic sexing strains of the medfly are discussed. (author). 31 refs

  1. Integrated gene mapping and synteny studies give insights into the evolution of a sex proto-chromosome in Solea senegalensis.

    Science.gov (United States)

    Portela-Bens, Silvia; Merlo, Manuel Alejandro; Rodríguez, María Esther; Cross, Ismael; Manchado, Manuel; Kosyakova, Nadezda; Liehr, Thomas; Rebordinos, Laureana

    2017-03-01

    The evolution of genes related to sex and reproduction in fish shows high plasticity and, to date, the sex determination system has only been identified in a few species. Solea senegalensis has 42 chromosomes and an XX/XY chromosome system for sex determination, while related species show the ZZ/ZW system. Next-generation sequencing (NGS), multi-color fluorescence in situ hybridization (mFISH) techniques, and bioinformatics analysis have been carried out, with the objective of revealing new information about sex determination and reproduction in S. senegalensis. To that end, several bacterial artificial chromosome (BAC) clones that contain candidate genes involved in such processes (dmrt1, dmrt2, dmrt3, dmrt4, sox3, sox6, sox8, sox9, lh, cyp19a1a, amh, vasa, aqp3, and nanos3) were analyzed and compared with the same region in other related species. Synteny studies showed that the co-localization of dmrt1-dmrt2-drmt3 in the largest metacentric chromosome of S. senegalensis is coincident with that found in the Z chromosome of Cynoglossus semilaevis, which would potentially make this a sex proto-chromosome. Phylogenetic studies show the close proximity of S. senegalensis to Oryzias latipes, a species with an XX/XY system and a sex master gene. Comparative mapping provides evidence of the preferential association of these candidate genes in particular chromosome pairs. By using the NGS and mFISH techniques, it has been possible to obtain an integrated genetic map, which shows that 15 out of 21 chromosome pairs of S. senegalensis have at least one BAC clone. This result is important for distinguishing those chromosome pairs of S. senegalensis that are similar in shape and size. The mFISH analysis shows the following co-localizations in the same chromosomes: dmrt1-dmrt2-dmrt3, dmrt4-sox9-thrb, aqp3-sox8, cyp19a1a-fshb, igsf9b-sox3, and lysg-sox6.

  2. Molecular cytogenetics and characterization of a ZZ/ZW sex chromosome system in Triportheus nematurus (Characiformes, Characidae).

    Science.gov (United States)

    Diniz, Débora; Moreira-Filho, Orlando; Bertollo, Luiz Antonio Carlos

    2008-05-01

    Chromosomes of Triportheus nematurus, a fish species from family Characidae, were analyzed in order to establish the conventional karyotype, location of C-band positive heterochromatin, Ag-NORs, GC- and AT-rich sites, and mapping of 18S and 5S rDNA with fluorescence in situ hybridization (FISH). The diploid number found was 2n = 52 chromosomes in both males and females. However, the females presented a pair of differentiated heteromorphic chromosomes, characterizing a ZZ/ZW sex chromosome system. The Z chromosome was metacentric and the largest one in the karyotype, bearing C-positive heterochromatin at pericentromeric and telomeric regions. The W chromosome was middle-sized submetacentric, appearing mostly heterochromatic after C-banding and presenting heterogeneous heterochromatin composed of GC- and AT-rich regions revealed by fluorochrome staining. Ag-NORs were also GC-rich and surrounded by heterochromatic regions, being located at the secondary constriction on the short arms of the second chromosome pair, in agreement with 18S rDNA sites detected with FISH. The 18S and 5S rDNA were aligned in tandem, representing an uncommon situation in fishes. The results obtained reinforce the basal condition of the ZZ/ZW sex system in the genus Triportheus, probably arisen prior to speciation in the group.

  3. Chimeric Sex-Determining Chromosomal Regions and Dysregulation of Cell-Type Identity in a Sterile Zygosaccharomyces Allodiploid Yeast.

    Directory of Open Access Journals (Sweden)

    Melissa Bizzarri

    Full Text Available Allodiploidization is a fundamental yet evolutionarily poorly characterized event, which impacts genome evolution and heredity, controlling organismal development and polyploid cell-types. In this study, we investigated the sex determination system in the allodiploid and sterile ATCC 42981 yeast, a member of the Zygosaccharomyces rouxii species complex, and used it to study how a chimeric mating-type gene repertoire contributes to hybrid reproductive isolation. We found that ATCC 42981 has 7 MAT-like (MTL loci, 3 of which encode α-idiomorph and 4 encode a-idiomorph. Two phylogenetically divergent MAT expression loci were identified on different chromosomes, accounting for a hybrid a/α genotype. Furthermore, extra a-idimorph-encoding loci (termed MTLa copies 1 to 3 were recognized, which shared the same MATa1 ORFs but diverged for MATa2 genes. Each MAT expression locus was linked to a HML silent cassette, while the corresponding HMR loci were located on another chromosome. Two putative parental sex chromosome pairs contributed to this unusual genomic architecture: one came from an as-yet-undescribed taxon, which has the NCYC 3042 strain as a unique representative, while the other did not match any MAT-HML and HMR organizations previously described in Z. rouxii species. This chimeric rearrangement produces two copies of the HO gene, which encode for putatively functional endonucleases essential for mating-type switching. Although both a and α coding sequences, which are required to obtain a functional cell-type a1-α2 regulator, were present in the allodiploid ATCC 42981 genome, the transcriptional circuit, which regulates entry into meiosis in response to meiosis-inducing salt stress, appeared to be turned off. Furthermore, haploid and α-specific genes, such as MATα1 and HO, were observed to be actively transcribed and up-regulated under hypersaline stress. Overall, these evidences demonstrate that ATCC 42981 is unable to repress haploid

  4. Sex differences in diurnal rhythms of food intake in mice caused by gonadal hormones and complement of sex chromosomes.

    Science.gov (United States)

    Chen, Xuqi; Wang, Lixin; Loh, Dawn H; Colwell, Christopher S; Taché, Yvette; Reue, Karen; Arnold, Arthur P

    2015-09-01

    We measured diurnal rhythms of food intake, as well as body weight and composition, while varying three major classes of sex-biasing factors: activational and organizational effects of gonadal hormones, and sex chromosome complement (SCC). Four Core Genotypes (FCG) mice, comprising XX and XY gonadal males and XX and XY gonadal females, were either gonad-intact or gonadectomized (GDX) as adults (2.5months); food intake was measured second-by-second for 7days starting 5weeks later, and body weight and composition were measured for 22weeks thereafter. Gonadal males weighed more than females. GDX increased body weight/fat of gonadal females, but increased body fat and reduced body weight of males. After GDX, XX mice had greater body weight and more fat than XY mice. In gonad-intact mice, males had greater total food intake and more meals than females during the dark phase, but females had more food intake and meals and larger meals than males during the light phase. GDX reduced overall food intake irrespective of gonad type or SCC, and eliminated differences in feeding between groups with different gonads. Diurnal phase of feeding was influenced by all three sex-biasing variables. Gonad-intact females had earlier onset and acrophase (peak) of feeding relative to males. GDX caused a phase-advance of feeding, especially in XX mice, leading to an earlier onset of feeding in GDX XX vs. XY mice, but earlier acrophase in GDX males relative to females. Gonadal hormones and SCC interact in the control of diurnal rhythms of food intake. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Effects of chromosomal sex and hormonal influences on shaping sex differences in brain and behavior: Lessons from cases of disorders of sex development.

    Science.gov (United States)

    Bramble, Matthew S; Lipson, Allen; Vashist, Neerja; Vilain, Eric

    2017-01-02

    Sex differences in brain development and postnatal behavior are determined largely by genetic sex and in utero gonadal hormone secretions. In humans however, determining the weight that each of these factors contributes remains a challenge because social influences should also be considered. Cases of disorders of sex development (DSD) provide unique insight into how mutations in genes responsible for gonadal formation can perturb the subsequent developmental hormonal milieu and elicit changes in normal human brain maturation. Specific forms of DSDs such as complete androgen insensitivity syndrome (CAIS), congenital adrenal hyperplasia (CAH), and 5α-reductase deficiency syndrome have variable effects between males and females, and the developmental outcomes of such conditions are largely dependent on sex chromosome composition. Medical and psychological works focused on CAH, CAIS, and 5α-reductase deficiency have helped form the foundation for understanding the roles of genetic and hormonal factors necessary for guiding human brain development. Here we highlight how the three aforementioned DSDs contribute to brain and behavioral phenotypes that can uniquely affect 46,XY and 46,XX individuals in dramatically different fashions. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. Diallel analysis for sex-linked and maternal effects.

    Science.gov (United States)

    Zhu, J; Weir, B S

    1996-01-01

    Genetic models including sex-linked and maternal effects as well as autosomal gene effects are described. Monte Carlo simulations were conducted to compare efficiencies of estimation by minimum norm quadratic unbiased estimation (MINQUE) and restricted maximum likelihood (REML) methods. MINQUE(1), which has 1 for all prior values, has a similar efficiency to MINQUE(θ), which requires prior estimates of parameter values. MINQUE(1) has the advantage over REML of unbiased estimation and convenient computation. An adjusted unbiased prediction (AUP) method is developed for predicting random genetic effects. AUP is desirable for its easy computation and unbiasedness of both mean and variance of predictors. The jackknife procedure is appropriate for estimating the sampling variances of estimated variances (or covariances) and of predicted genetic effects. A t-test based on jackknife variances is applicable for detecting significance of variation. Worked examples from mice and silkworm data are given in order to demonstrate variance and covariance estimation and genetic effect prediction.

  7. Sex-linked hypophosphatemia in adults: Prevalence of radiologic features

    International Nuclear Information System (INIS)

    Hardy, D.C.; Reid, I.R.; Whyte, M.P.; Murphy, W.A.

    1987-01-01

    The authors performed a retrospective radiologic review of 38 adults (23 women, 15 men; aged 17-77 years) with clinically proved sex-linked hypophosphatemia to determine the prevalence of certain radiologic features, to compare the findings in men (hemizygotes) with findings in women (heterozygotes), and to elucidate the natural history of the disease by comparing a younger group (n = 12; mean age, 18) with an older group (n = 26; mean age, 43). They found age-related diminished skeletal mass on visual and CT studies and increased numbers of bone reinforcement lines (osteopenia) and Looser zones (osteomalacia). Osteoarthritis developed in many joints (88% of the older group), including the knees (87%) ankles (78%), feet (71%), sacroiliac joints (48%), and wrists (43%). Chondrocalcinosis was uncommon. Enthesopathy was absent in the younger group but present in every member of the older group, and was often accompanied by extra ossicles (48% hands; 37% feet). Phalangeal sclerosis (9%) and spinous process bridging (4%) wre uncommon. Except for traction spurs in the older group (60%), the thoracolumbar spine was unremarkable. There was no lumbar spinal stenosis detected by either radiogrammetric or CT measurement. Curvatures of the lower extremity long bones were common in both age groups. In keeping with the mode of genetic transmission, men were more severely affected than women. The authors noted three other skeletal alterations not previously described: (1) flaring of the iliac wgins (33% of the younger group, 75% of the older group), (2) trapezoidal distal femoral condyles (67% vs. 68%), and (3) thick, flat tali (100% vs. 89%). Our study of a large population of adult subjects with sex-linked hypophosphatemia reveals a variety of progressive skeletal features

  8. Differentiation of sex chromosomes and karyotypic evolution in the eye-lid geckos (Squamata: Gekkota: Eublepharidae), a group with different modes of sex determination

    Czech Academy of Sciences Publication Activity Database

    Pokorná, M.; Rábová, Marie; Ráb, Petr; Kratochvíl, L.

    2010-01-01

    Roč. 18, č. 6 (2010), s. 748-748 ISSN 0967-3849. [19th International Colloquium on animal cytogenetics and gene mapping. 06.06.-09.06.2010, Krakow] Institutional research plan: CEZ:AV0Z50450515 Keywords : sex chromosomes * karyotypic evolution * eye-lid geckos Subject RIV: EB - Genetics ; Molecular Biology

  9. Evidence for linkage disequilibrium in chromosome 13-linked Duchenne-like muscular dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Othmane, K.B.; Speer, M.C.; Stauffer, J. [Duke Univ. Medical Center, Durham, NC (United States)] [and others

    1995-09-01

    Duchenne-like muscular dystrophy (DLMD) is an autosomal recessive Limb Girdle muscular dystrophy (LGMD2C) characterized by late age of onset, proximal muscle weakness leading to disability, high creatine kinase values, normal intelligence and normal dystrophin in muscle biopsy. We have shown previously that three DLMD families from Tunisia are linked to chromosome 13q12. To further localize the LGMD2C gene, we have investigated seven additional families (119 individuals). Both genotyping and two-point linkage analysis were performed as described elsewhere. 7 refs., 1 fig., 1 tab.

  10. Neurocognitive outcomes of individuals with a sex chromosome trisomy: XXX, XYY, or XXY: a systematic review*

    Science.gov (United States)

    LEGGETT, VICTORIA; JACOBS, PATRICIA; NATION, KATE; SCERIF, GAIA; BISHOP, DOROTHY V M

    2010-01-01

    Aim To review systematically the neurodevelopmental characteristics of individuals with sex chromosome trisomies (SCTs). Method A bibliographic search identified English-language articles on SCTs. The focus was on studies unbiased by clinical referral, with power of at least 0.69 to detect an effect size of 1.0. Results We identified 35 articles on five neonatally identified samples that had adequate power for our review. An additional 11 studies were included where cases had been identified for reasons other than neurodevelopmental concerns. Individuals with an additional X chromosome had mean IQs that were within broadly normal limits but lower than the respective comparison groups, with verbal IQ most affected. Cognitive outcomes were poorest for females with XXX. Males with XYY had normal-range IQs, but all three SCT groups (XXX, XXY, and XYY) had marked difficulties in speech and language, motor skills, and educational achievement. Nevertheless, most adults with SCTs lived independently. Less evidence was available for brain structure and for attention, social, and psychiatric outcomes. Within each group there was much variation. Interpretation Individuals with SCTs are at risk of cognitive and behavioural difficulties. However, the evidence base is slender, and further research is needed to ascertain the nature, severity, and causes of these difficulties in unselected samples. PMID:20059514

  11. Neurocognitive outcomes of individuals with a sex chromosome trisomy: XXX, XYY, or XXY: a systematic review.

    Science.gov (United States)

    Leggett, Victoria; Jacobs, Patricia; Nation, Kate; Scerif, Gaia; Bishop, Dorothy V M

    2010-02-01

    To review systematically the neurodevelopmental characteristics of individuals with sex chromosome trisomies (SCTs). A bibliographic search identified English-language articles on SCTs. The focus was on studies unbiased by clinical referral, with power of at least 0.69 to detect an effect size of 1.0. We identified 35 articles on five neonatally identified samples that had adequate power for our review. An additional 11 studies were included where cases had been identified for reasons other than neurodevelopmental concerns. Individuals with an additional X chromosome had mean IQs that were within broadly normal limits but lower than the respective comparison groups, with verbal IQ most affected. Cognitive outcomes were poorest for females with XXX. Males with XYY had normal-range IQs, but all three SCT groups (XXX, XXY, and XYY) had marked difficulties in speech and language, motor skills, and educational achievement. Nevertheless, most adults with SCTs lived independently. Less evidence was available for brain structure and for attention, social, and psychiatric outcomes. Within each group there was much variation. Individuals with SCTs are at risk of cognitive and behavioural difficulties. However, the evidence base is slender, and further research is needed to ascertain the nature, severity, and causes of these difficulties in unselected samples.

  12. Chromosomes

    Science.gov (United States)

    ... Care Genomic Medicine Working Group New Horizons and Research Patient Management Policy and Ethics Issues Quick Links for Patient Care Education All About the Human Genome Project Fact Sheets Genetic Education Resources for ...

  13. The fate of W chromosomes in hybrids between wild silkmoths, Samia cynthia ssp.: no role in sex determination and reproduction

    Czech Academy of Sciences Publication Activity Database

    Yoshido, Atsuo; Marec, František; Sahara, K.

    2016-01-01

    Roč. 116, č. 5 (2016), s. 424-433 ISSN 0018-067X R&D Projects: GA ČR(CZ) GA14-22765S Grant - others:The European Union Seventh Framework Programme (FP7/2007-2013)(CZ) 316304 Program:FP7 Institutional support: RVO:60077344 Keywords : hybrids * sex chromosomes * sex determination Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.961, year: 2016

  14. Machado-Joseph disease in pedigrees of Azorean descent is linked to chromosome 14.

    Science.gov (United States)

    St George-Hyslop, P; Rogaeva, E; Huterer, J; Tsuda, T; Santos, J; Haines, J L; Schlumpf, K; Rogaev, E I; Liang, Y; McLachlan, D R

    1994-07-01

    A locus for Machado-Joseph disease (MJD) has recently been mapped to a 30-cM region of chromosome 14q in five pedigrees of Japanese descent. MJD is a clinically pleomorphic neurodegenerative disease that was originally described in subjects of Azorean descent. In light of the nonallelic heterogeneity in other inherited spinocerebellar ataxias, we were interested to determine if the MJD phenotype in Japanese and Azorean pedigrees arose from mutations at the same locus. We provide evidence that MJD in five pedigrees of Azorean descent is also linked to chromosome 14q in an 18-cM region between the markers D14S67 and AACT (multipoint lod score +7.00 near D14S81). We also report molecular evidence for homozygosity at the MJD locus in an MJD-affected subject with severe, early-onset symptoms. These observations confirm the initial report of linkage of MJD to chromosome 14; suggest that MJD in Japanese and Azorean subjects may represent allelic or identical mutations at the same locus; and provide one possible explanation (MJD gene dosage) for the observed phenotypic heterogeneity in this disease.

  15. Not all hypochondroplasia families are linked to chromosome 4p16.3

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, F.; Munnich, A.; Merrer, M.Le. [INSERM, Paris (France)] [and others

    1994-09-01

    Achondroplasia (ACH, MIM 100800) and hypochondroplasia (HCH, MIM 146000) are short limb dwarfism with enlarged head sharing some specific radiological features. Inter- and intrafamilial clinical variability and histolopathological aspects of the growth cartilage suggested that ACH and HCH are allelic disorders. Recently, the gene for achondroplasia was mapped to chromosome 4p and no recombinants were found in 9 families with hypochondroplasia between D4S111 and the telomere (Zmax=1.70, {theta}=0). By using an additional polymorphic DNA marker which detects VNTR-like polymorphism at the D4S227 locus and a new microsatellite at locus D4S? (AFM163yc1), we observed recombinant events with markers of the chromosome 4p16.3 in 3/10 hypochondroplasia families, indicating that not all hypochondroplasia families are linked to chromosome 4p. A fibroblast growth factor receptor (FGFR3) expressed in chondrocytes during endochondral ossification which is located in the 2.5 Mb candidate region for achondroplasia was regarded as a good candidate gene. No major rearrangement of the FGFR3 gene was detected by Southern blot analysis using an FGFR3 cDNA probe. Further investigations will be required to conclude as to the possible involvement of this gene in ACH.

  16. Linking Y-chromosomal short tandem repeat loci to human male impulsive aggression.

    Science.gov (United States)

    Yang, Chun; Ba, Huajie; Cao, Yin; Dong, Guoying; Zhang, Shuyou; Gao, Zhiqin; Zhao, Hanqing; Zhou, Xianju

    2017-11-01

    Men are more susceptible to impulsive behavior than women. Epidemiological studies revealed that the impulsive aggressive behavior is affected by genetic factors, and the male-specific Y chromosome plays an important role in this behavior. In this study, we investigated the association between the impulsive aggressive behavior and Y-chromosomal short tandem repeats (Y-STRs) loci. The collected biologic samples from 271 offenders with impulsive aggressive behavior and 492 healthy individuals without impulsive aggressive behavior were amplified by PowerPlex R Y23 PCR System and the resultant products were separated by electrophoresis and further genotyped. Then, comparisons in allele and haplotype frequencies of the selected 22 Y-STRs were made in the two groups. Our results showed that there were significant differences in allele frequencies at DYS448 and DYS456 between offenders and controls ( p  impulsive aggression. However, the DYS448-DYS456-22-15 is less related to impulsive aggression. Our results suggest a link between Y-chromosomal allele types and male impulsive aggression.

  17. Genomic diversity in two related plant species with and without sex chromosomes--Silene latifolia and S. vulgaris.

    Directory of Open Access Journals (Sweden)

    Radim Cegan

    Full Text Available Genome size evolution is a complex process influenced by polyploidization, satellite DNA accumulation, and expansion of retroelements. How this process could be affected by different reproductive strategies is still poorly understood.We analyzed differences in the number and distribution of major repetitive DNA elements in two closely related species, Silene latifolia and S. vulgaris. Both species are diploid and possess the same chromosome number (2n = 24, but differ in their genome size and mode of reproduction. The dioecious S. latifolia (1C = 2.70 pg DNA possesses sex chromosomes and its genome is 2.5× larger than that of the gynodioecious S. vulgaris (1C = 1.13 pg DNA, which does not possess sex chromosomes. We discovered that the genome of S. latifolia is larger mainly due to the expansion of Ogre retrotransposons. Surprisingly, the centromeric STAR-C and TR1 tandem repeats were found to be more abundant in S. vulgaris, the species with the smaller genome. We further examined the distribution of major repetitive sequences in related species in the Caryophyllaceae family. The results of FISH (fluorescence in situ hybridization on mitotic chromosomes with the Retand element indicate that large rearrangements occurred during the evolution of the Caryophyllaceae family.Our data demonstrate that the evolution of genome size in the genus Silene is accompanied by the expansion of different repetitive elements with specific patterns in the dioecious species possessing the sex chromosomes.

  18. Neurocognitive Outcomes of Individuals with a Sex Chromosome Trisomy: XXX, XYY, or XXY--A Systematic Review

    Science.gov (United States)

    Leggett, Victoria; Jacobs, Patricia; Nation, Kate; Scerif, Gaia; Bishop, Dorothy V. M.

    2010-01-01

    Aim: To review systematically the neurodevelopmental characteristics of individuals with sex chromosome trisomies (SCTs). Method: A bibliographic search identified English-language articles on SCTs. The focus was on studies unbiased by clinical referral, with power of at least 0.69 to detect an effect size of 1.0. Results: We identified 35…

  19. The contribution of color to visual memory in X-chromosome-linked dichromats.

    Science.gov (United States)

    Gegenfurtner, K R; Wichmann, F A; Sharpe, L T

    1998-04-01

    We used a recognition memory paradigm to assess the visual memory of X-chromosome-linked dichromats for color images of natural scenes. The performance of 17 protanopes and 14 deuteranopes, who lack the second (red-green opponent) subsystem of color vision, but retain the primordial (yellow-blue opponent) subsystem, was compared with that of 36 color normal observers. During the presentation phase, 48 images of natural scenes were displayed on a CRT for durations between 50 and 1000 msec. Each image was followed by a random noise mask. Half of the images were presented in color and half in black and white. In the subsequent query phase, the same 48 images were intermixed with 48 new images and the subjects had to indicate which of the images they had already seen during the presentation phase. We find that the performance of the color normal observers increases with exposure duration. However, they perform 5-10% better for colored than for black and white images, even at exposure durations as short as 50 msec. Surprisingly, performance is not impaired for the dichromats, whose recognition performance is also better for colored than for black and white images. We conclude either that X-chromosome-linked dichromats may be able to compensate for their reduced chromatic information range when viewing complex natural scenes or that the chromatic information in most natural scenes, for the durations tested, is sufficiently represented by the surviving primordial color subsystem.

  20. A Dense Brown Trout (Salmo trutta) Linkage Map Reveals Recent Chromosomal Rearrangements in the Salmo Genus and the Impact of Selection on Linked Neutral Diversity

    Science.gov (United States)

    Leitwein, Maeva; Guinand, Bruno; Pouzadoux, Juliette; Desmarais, Erick; Berrebi, Patrick; Gagnaire, Pierre-Alexandre

    2017-01-01

    High-density linkage maps are valuable tools for conservation and eco-evolutionary issues. In salmonids, a complex rediploidization process consecutive to an ancient whole genome duplication event makes linkage maps of prime importance for investigating the evolutionary history of chromosome rearrangements. Here, we developed a high-density consensus linkage map for the brown trout (Salmo trutta), a socioeconomically important species heavily impacted by human activities. A total of 3977 ddRAD markers were mapped and ordered in 40 linkage groups using sex- and lineage-averaged recombination distances obtained from two family crosses. Performing map comparison between S. trutta and its sister species, S. salar, revealed extensive chromosomal rearrangements. Strikingly, all of the fusion and fission events that occurred after the S. salar/S. trutta speciation happened in the Atlantic salmon branch, whereas the brown trout remained closer to the ancestral chromosome structure. Using the strongly conserved synteny within chromosome arms, we aligned the brown trout linkage map to the Atlantic salmon genome sequence to estimate the local recombination rate in S. trutta at 3721 loci. A significant positive correlation between recombination rate and within-population nucleotide diversity (π) was found, indicating that selection constrains variation at linked neutral sites in brown trout. This new high-density linkage map provides a useful genomic resource for future aquaculture, conservation, and eco-evolutionary studies in brown trout. PMID:28235829

  1. A Dense Brown Trout (Salmo trutta Linkage Map Reveals Recent Chromosomal Rearrangements in the Salmo Genus and the Impact of Selection on Linked Neutral Diversity

    Directory of Open Access Journals (Sweden)

    Maeva Leitwein

    2017-04-01

    Full Text Available High-density linkage maps are valuable tools for conservation and eco-evolutionary issues. In salmonids, a complex rediploidization process consecutive to an ancient whole genome duplication event makes linkage maps of prime importance for investigating the evolutionary history of chromosome rearrangements. Here, we developed a high-density consensus linkage map for the brown trout (Salmo trutta, a socioeconomically important species heavily impacted by human activities. A total of 3977 ddRAD markers were mapped and ordered in 40 linkage groups using sex- and lineage-averaged recombination distances obtained from two family crosses. Performing map comparison between S. trutta and its sister species, S. salar, revealed extensive chromosomal rearrangements. Strikingly, all of the fusion and fission events that occurred after the S. salar/S. trutta speciation happened in the Atlantic salmon branch, whereas the brown trout remained closer to the ancestral chromosome structure. Using the strongly conserved synteny within chromosome arms, we aligned the brown trout linkage map to the Atlantic salmon genome sequence to estimate the local recombination rate in S. trutta at 3721 loci. A significant positive correlation between recombination rate and within-population nucleotide diversity (π was found, indicating that selection constrains variation at linked neutral sites in brown trout. This new high-density linkage map provides a useful genomic resource for future aquaculture, conservation, and eco-evolutionary studies in brown trout.

  2. Genes and chromosome arrangements affecting sex ratio in the Mediterranean fruit fly, Ceratitis capitata (Wied.)

    International Nuclear Information System (INIS)

    Wood, R.J.; Kafu, A.A.; Rendon Arana, P.A.; Owusu-Daaku, K.; Alcock, R.M.; Hallows, J.A.; Busch-Petersen, E.; Mani, G.S.

    1997-01-01

    The MP (male producing) factor, which shows temperature sensitive meiotic drive favoring the Y chromosome, proved to be highly variable in spermatozoal deficiency in different cysts within a single testis. However, the overall loss of sperm corresponded almost precisely with the loss of females. The minimum proportion of females consistently obtained in inbred lines was about 30-35%. On the basis of parallel studies with the mosquito Aedes aegypti, variability between cysts is open to interpretation in terms of different rates of senescence. The T:Y(wp + )30C genetic sexing strain, which is designed to generate males with brown (wild type) puparia and females with white puparia, was contaminated artificially in a series of population experiments to investigate the pattern of breakdown. Wild type contamination with either sex caused an increase of brown pupae. The sex ratio became progressively distorted in favour of females after contamination with females, mated or unmated, but not after male contamination. The experiments revealed evidence of a low frequency of natural recombination between wp + and the translocation breakpoint on the Y chromosome, shown by the appearance of wp males. The frequency of male recombination (r) and the selection coefficient (s) against wp/wp were measured over 11 generations. The best fit to the observed data was obtained with r = (0.14 ± 0.04)% and s=(26.0 ± 2.7)%. Using these estimates to predict the frequency of wp + females and wp males for up to 100 generations, it was concluded that white males would never exceed 0.5% whereas the frequency of brown females was expected to exceed 33% after 25 generations. Published data on the mass reared strain, maintained with a population size of 240,000 adult flies, were subjected to the same analysis. A higher value of s between (38.0 ± 3.2)% and (52.0 ± 0.3)% was obtained under these conditions. Electrophoretic studies on esterases revealed a significantly higher activity in a recently

  3. An immunological approach of sperm sexing and different methods for identification of X- and Y-chromosome bearing sperm

    Directory of Open Access Journals (Sweden)

    Shiv Kumar Yadav

    2017-05-01

    Full Text Available Separation of X- and Y-chromosome bearing sperm has been practiced for selection of desired sex of offspring to increase the profit in livestock industries. At present, fluorescence-activated cell sorter is the only successful method for separation of X- and Y-chromosome bearing sperm. This technology is based on the differences in DNA content between these two types of sperm and has been commercialized for bovine sperm. However, this technology still has problems in terms of high economic cost, sperm damage, and lower pregnancy rates compared to unsorted semen. Therefore, an inexpensive, convenient, and non-invasive approach for sperm sexing would be of benefit to agricultural sector. Within this perspective, immunological sperm sexing method is one of the attractive choices to separate X- and Y-chromosome bearing sperm. This article reviews the current knowledge about immunological approaches, viz., H-Y antigen, sex-specific antigens, and differentially expressed proteins for sperm sexing. Moreover, this review also highlighted the different methods for identification of X- and Y-sperm.

  4. Sex difference in link between interleukin-6 and stress.

    Science.gov (United States)

    Jankord, Ryan; Turk, James R; Schadt, James C; Casati, Jennifer; Ganjam, Venkataseshu K; Price, Elmer M; Keisler, Duane H; Laughlin, M Harold

    2007-08-01

    Inflammation contributes to disease development, and the neuroimmunoendocrine interface is a potential site of action for inflammatory products like IL-6 to affect health. Although plasma IL-6 can stimulate the activity of the hypothalamo-pituitary-adrenocortical (HPA) axis, the precise role, if any, for IL-6 in the HPA response to nonimmunological stressors is unclear. The purpose of this study was to test the hypothesis that IL-6 in the stalk median eminence (SME) can be directly involved in stimulating ACTH secretion in response to acute stress in female swine. This study was undertaken as a result of finding IL-6 localized to the external zone of the SME next to the hypophyseal portal vessels. Results indicate that content of IL-6 in the SME decreases in response to acute stress along with an increase in nuclear phosphorylated signal transducer and activator of transcription-3 (pSTAT-3) in pituitary corticotrophs and a simultaneous increase in plasma concentrations of IL-6 and ACTH. Furthermore, we show that females concomitantly display greater SME content of IL-6 and greater HPA responsiveness to stress, thereby suggesting that IL-6 release from the SME is an integral factor contributing to enhanced stress responsiveness in females. Our results provide evidence for a direct link between IL-6 and ACTH release and reveal a sex difference in this relationship.

  5. Sex Difference in Link between IL-6 and Stress

    Science.gov (United States)

    Jankord, Ryan; Turk, James R.; Schadt, James C.; Casati, Jennifer; Ganjam, Venkataseshu K.; Price, Elmer M.; Keisler, Duane H.; Laughlin, M. Harold

    2009-01-01

    Inflammation contributes to disease development, and the neuro-immuno-endocrine interface is a potential site of action for inflammatory products like IL-6 to affect health. Although plasma IL-6 can stimulate the activity of the hypothalamo-pituitary-adrenocortical (HPA) axis, the precise role, if any, for IL-6 in the HPA response to non-immunological stressors is unclear. The purpose of this study was to test the hypothesis that IL-6 in the stalk median eminence (SME) can be directly involved in stimulating ACTH secretion in response to acute stress in female swine. This study was undertaken as a result of finding IL-6 localized to the external zone of the stalk median eminence (SME) next to the hypophyseal portal vessels. Results indicate that content of IL-6 in the SME decreases in response to acute stress along with an increase in phosphorylation of STAT3 in the anterior pituitary and a simultaneous increase in plasma concentrations of IL-6 and ACTH. Furthermore, we show that females concomitantly display greater SME content of IL-6 and greater HPA responsiveness to stress, thereby suggesting that IL-6 release from the SME is an integral factor contributing to enhanced stress responsiveness in females. Our results provide evidence for a direct link between IL-6 and ACTH release and reveal a sex difference in this relationship. PMID:17510233

  6. Correction to: Whole chromosome painting reveals independent origin of sex chromosomes in closely related forms of a fish species.

    Science.gov (United States)

    Cioffi, Marcelo de Bello; Sánchez, Antonio; Marchal, Juan Alberto; Kosyakova, Nadezda; Liehr, Thomas; Trifonov, Vladimir; Bertollo, Luiz Antonio Carlos

    2018-02-01

    ere, we report that a paragraph from the "Discussion" section of Cioffi et al. (2011; p. 1070, 4th paragraph of column 1) was transcribed (with only minor edits) from an introductory paragraph previously published in Chromosome Research by O'Meally et al.

  7. Editorial: X-chromosome-linked Kallmann's syndrome: Pathology at the molecular level

    Energy Technology Data Exchange (ETDEWEB)

    Prager, D.; Braunstein, G.D. (Cedars-Sinai Medical Center, Los Angeles, CA (United States))

    1993-04-01

    Kallmann's syndrome or olfactogenital dysplasia refers to a disorder characterized by hypogonadotropic hypogonadism and anosmia or hyposmia which can occur sporadically or in a familial setting. Originally described in 1856, the first familial cases were reported by Kallmann et al., in 1944. Based on segregation analysis of multiple families, three modes of transmission have been documented: X-linked, autosomal dominant with variable penetrance, and autosomal recessive. Kallmann's syndrome occurs in less than 1 in 10,000 male births, with a 5-fold excess of affected males to females, suggesting that the X-linked form is the most frequent. By genetic linkage analysis the X-linked form of Kallmann's syndrome was localized to Xp22.3. This was confirmed by the description of patients with contiguous gene syndromes due to deletions of various portions of the distal short arm of the X-chromosome. Such patients present with complex phenotypes characterized by a combination of Kallmann's syndrome with X-linked icthyosis due to steroid sulfatase deficiency, chondrodysplasia punctata, short stature, and mental retardation. DNA analysis has identified and mapped the genes responsible for these disorders. 10 refs., 1 fig., 1 tab.

  8. Sex reversal in the mouse (Mus musculus) is caused by a recurrent nonreciprocal crossover involving the x and an aberrant y chromosome.

    Science.gov (United States)

    Singh, L; Jones, K W

    1982-02-01

    Satellite DNA (Bkm) from the W sex-determining chromosome of snakes, which is related to sequences on the mouse Y chromosome, has been used to analyze the DNA and chromosomes of sex-reversed (Sxr) XXSxr male mice. Such mice exhibit a male-specific Southern blot Bkm hybridization pattern, consistent with the presence of Y-chromosome DNA. In situ hybridization of Bkm to chromosomes of XXSxr mice shows an aberrant concentration of related sequences on the distal terminus of a large mouse chromosome. The XYSxr carrier male, however, shows a pair of small chromosomes, which are presumed to be aberrant Y derivatives. Meiosis in the XYSxr mouse involves transfer of chromatin rich in Bkm-related DNA from the Y-Y1 complex to the X distal terminus. We suggest that this event is responsible for the transmission of the Sxr trait.

  9. A new resource for characterizing X-linked genes in Drosophila melanogaster: systematic coverage and subdivision of the X chromosome with nested, Y-linked duplications.

    Science.gov (United States)

    Cook, R Kimberley; Deal, Megan E; Deal, Jennifer A; Garton, Russell D; Brown, C Adam; Ward, Megan E; Andrade, Rachel S; Spana, Eric P; Kaufman, Thomas C; Cook, Kevin R

    2010-12-01

    Interchromosomal duplications are especially important for the study of X-linked genes. Males inheriting a mutation in a vital X-linked gene cannot survive unless there is a wild-type copy of the gene duplicated elsewhere in the genome. Rescuing the lethality of an X-linked mutation with a duplication allows the mutation to be used experimentally in complementation tests and other genetic crosses and it maps the mutated gene to a defined chromosomal region. Duplications can also be used to screen for dosage-dependent enhancers and suppressors of mutant phenotypes as a way to identify genes involved in the same biological process. We describe an ongoing project in Drosophila melanogaster to generate comprehensive coverage and extensive breakpoint subdivision of the X chromosome with megabase-scale X segments borne on Y chromosomes. The in vivo method involves the creation of X inversions on attached-XY chromosomes by FLP-FRT site-specific recombination technology followed by irradiation to induce large internal X deletions. The resulting chromosomes consist of the X tip, a medial X segment placed near the tip by an inversion, and a full Y. A nested set of medial duplicated segments is derived from each inversion precursor. We have constructed a set of inversions on attached-XY chromosomes that enable us to isolate nested duplicated segments from all X regions. To date, our screens have provided a minimum of 78% X coverage with duplication breakpoints spaced a median of nine genes apart. These duplication chromosomes will be valuable resources for rescuing and mapping X-linked mutations and identifying dosage-dependent modifiers of mutant phenotypes.

  10. Insights into the evolution of mammalian telomerase: Platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes

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    Hrdličková Radmila

    2012-06-01

    Full Text Available Abstract Background The TERT gene encodes the catalytic subunit of the telomerase complex and is responsible for maintaining telomere length. Vertebrate telomerase has been studied in eutherian mammals, fish, and the chicken, but less attention has been paid to other vertebrates. The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes. We report the cloning of a platypus TERT (OanTERT ortholog, and provide a comparison with genes of other vertebrates. Results The OanTERT encodes a protein with a high sequence similarity to marsupial TERT and avian TERT. Like the TERT of sauropsids and marsupials, as well as that of sharks and echinoderms, OanTERT contains extended variable linkers in the N-terminal region suggesting that they were present already in basal vertebrates and lost independently in ray-finned fish and eutherian mammals. Several alternatively spliced OanTERT variants structurally similar to avian TERT variants were identified. Telomerase activity is expressed in all platypus tissues like that of cold-blooded animals and murine rodents. OanTERT was localized on pseudoautosomal regions of sex chromosomes X3/Y2, expanding the homology between human chromosome 5 and platypus sex chromosomes. Synteny analysis suggests that TERT co-localized with sex-linked genes in the last common mammalian ancestor. Interestingly, female platypuses express higher levels of telomerase in heart and liver tissues than do males. Conclusions OanTERT shares many features with TERT of the reptilian outgroup, suggesting that OanTERT represents the ancestral mammalian TERT. Features specific to TERT of eutherian mammals have, therefore, evolved more recently after the divergence of monotremes.

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

    Czech Academy of Sciences Publication Activity Database

    Hobza, Roman; Lengerová, Martina; Svoboda, J.; Kubeková, H.; Kejnovský, Eduard; Vyskot, Boris

    2006-01-01

    Roč. 115, č. 5 (2006), s. 376-382 ISSN 0009-5915 R&D Projects: GA ČR(CZ) GA521/06/0056; GA ČR(CZ) GA204/05/2097 Institutional research plan: CEZ:AV0Z50040507 Keywords : plant melandrium-album * dioecious plant * X-chromosome Subject RIV: BO - Biophysics Impact factor: 4.065, year: 2006

  12. Polytene chromosomes of monogenic and amphogenic Chrysomya species (Calliphoridae, Diptera): analysis of banding patterns and in situ hybridization with Drosophila sex determining gene sequences.

    Science.gov (United States)

    Puchalla, S

    1994-03-01

    Standard maps for the five banded polytene chromosomes found in trichogen cell nuclei of the monogenic blowfly Chrysomya rufifacies and the amphogenic Chrysomya pinguis are presented. The chromosomes are highly homologous in the two species; differences in banding patterns are predominantly caused by one pericentric and ten paracentric inversions. In chromosome 5 of the amphogenic Chrysomya phaonis, also analysed in this paper, an additional paracentric inversion was observed. The distribution of species specific inversions indicates that the monogenic C. rufifacies is phylogenetically older than the amphogenic species. The maternal sex realizer locus F'/f on polytene chromosome 5 of C. rufifacies is not associated with a structural heterozygosity. Chromosome pair 6 of C. rufifacies and the sex chromosome pair of C. pinguis are under-replicated in polytene nuclei; they consist of irregular chromatin granules, frequently associated with nucleolus material. Evolution of heteromorphic sex chromosomes in Chrysomya is probably correlated with heterochromatin accumulation. A search for sex determining genes in Chrysomya was initiated using sex determining sequences from Drosophila melanogaster for in situ hybridization. The polytene band 41A1 on chromosome 5 of monogenic and amphogenic Chrysomya species contains sequences homologous to the maternal sex determining gene daughterless (da). Homology to the zygotic gene Sex-lethal (Sxl) of Drosophila is detected in band 39A1 on chromosome 5 of C. rufifacies. The findings reported here are the first evidence for a possible homology between the da gene of Drosophila and the maternal sex realizer F' of C. rufifacies. An hypothesis for the evolution of the maternal effect sex determination of C. rufifacies is proposed.

  13. Accounting for eXentricities: analysis of the X chromosome in GWAS reveals X-linked genes implicated in autoimmune diseases.

    Directory of Open Access Journals (Sweden)

    Diana Chang

    Full Text Available Many complex human diseases are highly sexually dimorphic, suggesting a potential contribution of the X chromosome to disease risk. However, the X chromosome has been neglected or incorrectly analyzed in most genome-wide association studies (GWAS. We present tailored analytical methods and software that facilitate X-wide association studies (XWAS, which we further applied to reanalyze data from 16 GWAS of different autoimmune and related diseases (AID. We associated several X-linked genes with disease risk, among which (1 ARHGEF6 is associated with Crohn's disease and replicated in a study of ulcerative colitis, another inflammatory bowel disease (IBD. Indeed, ARHGEF6 interacts with a gastric bacterium that has been implicated in IBD. (2 CENPI is associated with three different AID, which is compelling in light of known associations with AID of autosomal genes encoding centromere proteins, as well as established autosomal evidence of pleiotropy between autoimmune diseases. (3 We replicated a previous association of FOXP3, a transcription factor that regulates T-cell development and function, with vitiligo; and (4 we discovered that C1GALT1C1 exhibits sex-specific effect on disease risk in both IBDs. These and other X-linked genes that we associated with AID tend to be highly expressed in tissues related to immune response, participate in major immune pathways, and display differential gene expression between males and females. Combined, the results demonstrate the importance of the X chromosome in autoimmunity, reveal the potential of extensive XWAS, even based on existing data, and provide the tools and incentive to properly include the X chromosome in future studies.

  14. Transcriptome profiling of Nasonia vitripennis testis reveals novel transcripts expressed from the selfish B chromosome, paternal sex ratio.

    Science.gov (United States)

    Akbari, Omar S; Antoshechkin, Igor; Hay, Bruce A; Ferree, Patrick M

    2013-09-04

    A widespread phenomenon in nature is sex ratio distortion of arthropod populations caused by microbial and genetic parasites. Currently little is known about how these agents alter host developmental processes to favor one sex or the other. The paternal sex ratio (PSR) chromosome is a nonessential, paternally transmitted centric fragment that segregates in natural populations of the jewel wasp, Nasonia vitripennis. To persist, PSR is thought to modify the hereditary material of the developing sperm, with the result that all nuclear DNA other than the PSR chromosome is destroyed shortly after fertilization. This results in the conversion of a fertilized embryo--normally a female--into a male, thereby insuring transmission of the "selfish" PSR chromosome, and simultaneously leading to wasp populations that are male-biased. To begin to understand this system at the mechanistic level, we carried out transcriptional profiling of testis from WT and PSR-carrying males. We identified a number of transcripts that are differentially expressed between these conditions. We also discovered nine transcripts that are uniquely expressed from the PSR chromosome. Four of these PSR-specific transcripts encode putative proteins, whereas the others have very short open reading frames and no homology to known proteins, suggesting that they are long noncoding RNAs. We propose several different models for how these transcripts could facilitate PSR-dependent effects. Our analyses also revealed 15.71 MB of novel transcribed regions in the N. vitripennis genome, thus increasing the current annotation of total transcribed regions by 53.4%. Finally, we detected expression of multiple meiosis-related genes in the wasp testis, despite the lack of conventional meiosis in the male sex.

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

    Czech Academy of Sciences Publication Activity Database

    Yoshido, A.; Sahara, K.; Marec, František; Matsuda, Y.

    2011-01-01

    Roč. 106, č. 4 (2011), s. 614-624 ISSN 0018-067X R&D Projects: GA AV ČR IAA600960925 Grant - others:Japan Society for the Promotion of Science(JP) 19-1114; Japan Society for the Promotion of Science(JP) 21-7147 Institutional research plan: CEZ:AV0Z50070508 Keywords : Lepidoptera * sex chromosomes * fluorescences Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.597, year: 2011

  16. Y-chromosomal diversity in Haiti and Jamaica: contrasting levels of sex-biased gene flow.

    Science.gov (United States)

    Simms, Tanya M; Wright, Marisil R; Hernandez, Michelle; Perez, Omar A; Ramirez, Evelyn C; Martinez, Emanuel; Herrera, Rene J

    2012-08-01

    Although previous studies have characterized the genetic structure of populations from Haiti and Jamaica using classical and autosomal STR polymorphisms, the patrilineal influences that are present in these countries have yet to be explored. To address this lacuna, the current study aims to investigate, for the first time, the potential impact of different ancestral sources, unique colonial histories, and distinct family structures on the paternal profile of both groups. According to previous reports examining populations from the Americas, island-specific demographic histories can greatly impact population structure, including various patterns of sex-biased gene flow. Also, given the contrasting autosomal profiles provided in our earlier study (Simms et al.: Am J Phys Anthropol 142 (2010) 49-66), we hypothesize that the degree and directionality of gene flow from Europeans, Africans, Amerindians, and East Asians are dissimilar in the two countries. To test this premise, 177 high-resolution Y-chromosome binary markers and 17 Y-STR loci were typed in Haiti (n = 123) and Jamaica (n = 159) and subsequently utilized for phylogenetic comparisons to available reference collections encompassing Africa, Europe, Asia (East and South), and the New World. Our results reveal that both studied populations exhibit a predominantly South-Saharan paternal component, with haplogroups A1b-V152, A3-M32, B2-M182, E1a-M33, E1b1a-M2, E2b-M98, and R1b2-V88 comprising 77.2% and 66.7% of the Haitian and Jamaican paternal gene pools, respectively. Yet, European derived chromosomes (i.e., haplogroups G2a*-P15, I-M258, R1b1b-M269, and T-M184) were detected at commensurate levels in Haiti (20.3%) and Jamaica (18.9%), whereas Y-haplogroups indicative of Chinese [O-M175 (3.8%)] and Indian [H-M69 (0.6%) and L-M20 (0.6%)] ancestry were restricted to Jamaica. Copyright © 2012 Wiley Periodicals, Inc.

  17. The eXtroardinarY Babies Study: Natural History of Health and Neurodevelopment in Infants and Young Children With Sex Chromosome Trisomy

    Science.gov (United States)

    2018-01-10

    Klinefelter Syndrome; Trisomy X; XYY Syndrome; XXXY and XXXXY Syndrome; Xxyy Syndrome; Xyyy Syndrome; Xxxx Syndrome; Xxxxx Syndrome; Xxxyy Syndrome; Xxyyy Syndrome; Xyyyy Syndrome; Male With Sex Chromosome Mosaicism

  18. Different perspectives on the sex-attachment link: towards an emotion-motivational account.

    Science.gov (United States)

    Dewitte, Marieke

    2012-01-01

    Although the link between sex and attachment was made decades ago (Hazan & Shaver, 1987), theories on sexual and attachment functioning have been developed in relative isolation. Recent efforts to integrate both literatures have been complicated by the fact that the sex-attachment link has been approached from very different perspectives, including biological, evolutionary, developmental, cognitive, and social psychology approaches. Also, at the empirical level, research on sex and attachment lacks overarching synthesis. This article gives an overview of the most important theoretical ideas and empirical insights on sex and attachment. It starts with describing general models that approach the sex-attachment link from an evolutionary and neurobiological perspective. Then, it summarizes theoretical and empirical ideas of attachment theory and describes how attachment style differences are manifested in intimate and sexual relationships. Research so far has been limited to studying the predicted link between sex and attachment in terms of broad descriptives, and it would benefit the literature to specify the processes and pathways that mediate the sex-attachment link. After a short discussion of the functional similarities between the sexual and the attachment systems, the article describes some specific--dynamical--models that focus on the emotional and cognitive-motivational processes through which attachment schemas influence sexual experiences. Such an emotion-motivational perspective on sex and attachment can help to organize theoretical ideas and empirical findings and eventually promote an integrative view on how attachment dynamics can interact with sexual experiences.

  19. Sex-linked strategies of human reproductive behavior.

    Science.gov (United States)

    Jaffe, K; Urribarri, D; Chacon, G C; Diaz, G; Torres, A; Herzog, G

    1993-01-01

    We present data on fertility characteristics in the Venezuelan population for each sex separately, allowing a detailed comparative analysis of the variance in fertility between males and females. We show that the fertility distribution for both sexes is discontinuous, that the average female has a larger number of offspring per individual than the average male, and that highly fertile males outnumber highly fertile females so that the total number of offspring produced by males and females is balanced. Results indicate that a few males are responsible for a relative higher fertility of the average female and that interactions between polyandric females with monogamic and polygynic males are common. Among the Yanomami, a relatively unacculturated hunter-gatherer-horticulturist tribe, similar differences in fertility distribution of both sexes are apparent. The data suggest that human populations contain statistically distinct subpopulations, with different reproductive strategies, suggesting the existence of complex interactions among human populations which are not evident from the study of individuals or groups.

  20. Sixteen kiwi (Apteryx spp) transcriptomes provide a wealth of genetic markers and insight into sex chromosome evolution in birds.

    Science.gov (United States)

    Ramstad, Kristina M; Miller, Hilary C; Kolle, Gabriel

    2016-05-26

    Kiwi represent the most basal extant avian lineage (paleognaths) and exhibit biological attributes that are unusual or extreme among living birds, such as large egg size, strong olfaction, nocturnality, flightlessness and long lifespan. Despite intense interest in their evolution and their threatened status, genomic resources for kiwi were virtually non-existent until the recent publication of a single genome. Here we present the most comprehensive kiwi transcriptomes to date, obtained via Illumina sequencing of whole blood and de novo assembly of mRNA sequences of eight individuals from each of the two rarest kiwi species, little spotted kiwi (LSK; Apteryx owenii) and rowi (A. rowi). Sequences obtained were orthologous with a wide diversity of functional genes despite the sequencing of a single tissue type. Individual and composite assemblies contain more than 7900 unique protein coding transcripts in each of LSK and rowi that show strong homology with chicken (Gallus gallus), including those associated with growth, development, disease resistance, reproduction and behavior. The assemblies also contain 66,909 SNPs that distinguish between LSK and rowi, 12,384 SNPs among LSK (associated with 3088 genes), and 29,313 SNPs among rowi (associated with 4953 genes). We found 3084 transcripts differentially expressed between LSK and rowi and 150 transcripts differentially expressed between the sexes. Of the latter, 83 could be mapped to chicken chromosomes with 95% syntenic with chromosome Z. Our study has simultaneously sequenced multiple species, sexes, and individual kiwi at thousands of genes, and thus represents a significant leap forward in genomic resources available for kiwi. The expression pattern we observed among chromosome Z related genes in kiwi is similar to that observed in ostriches and emu, suggesting a common and ancestral pattern of sex chromosome homomorphy, recombination, and gene dosage among living paleognaths. The transcriptome assemblies described

  1. A Tandem Duplicate of Anti-Müllerian Hormone with a Missense SNP on the Y Chromosome Is Essential for Male Sex Determination in Nile Tilapia, Oreochromis niloticus

    Science.gov (United States)

    Li, Minghui; Sun, Yunlv; Zhao, Jiue; Shi, Hongjuan; Zeng, Sheng; Ye, Kai; Jiang, Dongneng; Zhou, Linyan; Sun, Lina; Tao, Wenjing; Nagahama, Yoshitaka; Kocher, Thomas D.; Wang, Deshou

    2015-01-01

    Variation in the TGF-β signaling pathway is emerging as an important mechanism by which gonadal sex determination is controlled in teleosts. Here we show that amhy, a Y-specific duplicate of the anti-Müllerian hormone (amh) gene, induces male sex determination in Nile tilapia. amhy is a tandem duplicate located immediately downstream of amhΔ-y on the Y chromosome. The coding sequence of amhy was identical to the X-linked amh (amh) except a missense SNP (C/T) which changes an amino acid (Ser/Leu92) in the N-terminal region. amhy lacks 5608 bp of promoter sequence that is found in the X-linked amh homolog. The amhΔ-y contains several insertions and deletions in the promoter region, and even a 5 bp insertion in exonVI that results in a premature stop codon and thus a truncated protein product lacking the TGF-β binding domain. Both amhy and amhΔ-y expression is restricted to XY gonads from 5 days after hatching (dah) onwards. CRISPR/Cas9 knockout of amhy in XY fish resulted in male to female sex reversal, while mutation of amhΔ-y alone could not. In contrast, overexpression of Amhy in XX fish, using a fosmid transgene that carries the amhy/amhΔ-y haplotype or a vector containing amhy ORF under the control of CMV promoter, resulted in female to male sex reversal, while overexpression of AmhΔ-y alone in XX fish could not. Knockout of the anti-Müllerian hormone receptor type II (amhrII) in XY fish also resulted in 100% complete male to female sex reversal. Taken together, these results strongly suggest that the duplicated amhy with a missense SNP is the candidate sex determining gene and amhy/amhrII signal is essential for male sex determination in Nile tilapia. These findings highlight the conserved roles of TGF-β signaling pathway in fish sex determination. PMID:26588702

  2. Molecular patterns of X chromosome-linked color vision genes among 134 menof European ancestry

    International Nuclear Information System (INIS)

    Drummond-Borg, M.; Deeb, S.S.; Motulsky, A.G.

    1989-01-01

    The authors used Southern blot hybridization to study X chromosome-linked color vision genes encoding the apoproteins of red and green visual pigments in 134 unselected Caucasian men. One hundred and thirteen individuals (84.3%) had a normal arrangement of their color vision pigment genes. All had one red pigment gene; the number of green pigment genes ranged from one to five with a mode of two. The frequency of molecular genotypes indicative of normal color vision (84.3%) was significantly lower than had been observed in previous studies of color vision phenotypes. Color vision defects can be due to deletions of red or green pigment genes or due to formation of hybrid genes comprising portions of both red and green pigment genes. Characteristic anomalous patterns were seen in 15 (11.2%) individuals: 7 (5.2%) had patterns characteristic of deuteranomaly, 2 (1.5%) had patterns characteristic of deuteranopia, and 6 (4.5%) had protan patterns. Previously undescribed hybrid gene patterns consisting of both green and red pigment gene fragments in addition to normal red and green genes were observed in another 6 individuals (4.5%). Thus, DNA testing detected anomalous color vision pigment genes at a higher frequency than expected from phenotypic color vision tests

  3. Prion disease resembling frontotemporal dementia and parkinsonism linked to chromosome 17

    Directory of Open Access Journals (Sweden)

    Nitrini Ricardo

    2001-01-01

    Full Text Available OBJECTIVE: To compare the clinical features of a familial prion disease with those of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17. BACKGROUND: Prion diseases are not usually considered in the differential diagnosis of FTDP-17, since familial Creutzfeldt-Jakob disease (CJD, the most common inherited prion disease, often manifests as a rapidly progressive dementia. Conversely, FTDP-17 usually has an insidious onset in the fifth decade, with abnormal behavior and parkinsonian features. METHOD: We present the clinical features of 12 patients from a family with CJD associated with a point mutation at codon 183 of the prion protein gene. RESULTS: The mean age at onset was 44.0 ± 3.7; the duration of the symptoms until death ranged from two to nine years. Behavioral disturbances were the predominant presenting symptoms. Nine patients were first seen by psychiatrists. Eight patients manifested parkinsonian signs. CONCLUSION: These clinical features bear a considerable resemblance to those described in FTDP-17.

  4. Maternal condition but not corticosterone is linked to offspring sex ratio in a passerine bird.

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    Lindsay J Henderson

    Full Text Available There is evidence of offspring sex ratio adjustment in a range of species, but the potential mechanisms remain largely unknown. Elevated maternal corticosterone (CORT is associated with factors that can favour brood sex ratio adjustment, such as reduced maternal condition, food availability and partner attractiveness. Therefore, the steroid hormone has been suggested to play a key role in sex ratio manipulation. However, despite correlative and causal evidence CORT is linked to sex ratio manipulation in some avian species, the timing of adjustment varies between studies. Consequently, whether CORT is consistently involved in sex-ratio adjustment, and how the hormone acts as a mechanism for this adjustment remains unclear. Here we measured maternal baseline CORT and body condition in free-living blue tits (Cyanistes caeruleus over three years and related these factors to brood sex ratio and nestling quality. In addition, a non-invasive technique was employed to experimentally elevate maternal CORT during egg laying, and its effects upon sex ratio and nestling quality were measured. We found that maternal CORT was not correlated with brood sex ratio, but mothers with elevated CORT fledged lighter offspring. Also, experimental elevation of maternal CORT did not influence brood sex ratio or nestling quality. In one year, mothers in superior body condition produced male biased broods, and maternal condition was positively correlated with both nestling mass and growth rate in all years. Unlike previous studies maternal condition was not correlated with maternal CORT. This study provides evidence that maternal condition is linked to brood sex ratio manipulation in blue tits. However, maternal baseline CORT may not be the mechanistic link between the maternal condition and sex ratio adjustment. Overall, this study serves to highlight the complexity of sex ratio adjustment in birds and the difficulties associated with identifying sex biasing mechanisms.

  5. Karyotype characterization and ZZ/ZW sex chromosome heteromorphism in two species of the catfish genus Ancistrus Kner, 1854 (Siluriformes: Loricariidae from the Amazon basin

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    Renildo R. de Oliveira

    Full Text Available We present karyotypic characteristics and report on the occurrence of ZZ/ZW sex chromosomes in Ancistrus ranunculus (rio Xingu and Ancistrus sp. "Piagaçu" (rio Purus, of the Brazilian Amazon. Ancistrus ranunculus has a modal number of 2n=48 chromosomes, a fundamental number (FN of 82 for both sexes, and the karyotypic formula was 20m+8sm+6st+14a for males and 19m+9sm+6st+14a for females. Ancistrus sp. "Piagaçu" presented 2n=52 chromosomes, FN= 78 for males and FN= 79 for females. The karyotypic formula was 16m+8sm+2st+26a for males and 16m+9sm+2st+25a for females. The high number of acrocentric chromosomes in karyotype of Ancistrus sp. "Piagaçu" differs from the majority of Ancistrini genera studied so far, and may have resulted from pericentric inversions and translocations. The lower number of chromosomes in A. ranunculus indicates that centric fusions also occurred in the evolution of Ancistrus karyotypes. We conclude that karyotypic characteristics and the presence of sex chromosomes can constitute important cytotaxonomic markers to identify cryptic species of Ancistrus. However, sex chromosomes apparently arose independently within the genus and thus do not constitute a reliable character to analyze phylogenetic relations among Ancistrus species.

  6. Links between sex-typed time use in middle childhood and gender development in early adolescence.

    Science.gov (United States)

    McHale, Susan M; Kim, Ji-Yeon; Whiteman, Shawn; Crouter, Ann C

    2004-09-01

    The authors studied sex-typing in the kinds (e.g., sports, handicrafts) and social contexts (same- vs. other-sex companions) of children's free time activities, and the links between sex-typed activities and gender development over 2 years. Participants were 200 White, working- and middle-class children (103 girls, 97 boys; mean age = 10.86 years). In annual home interviews, children rated their self-esteem, gender role attitudes and sex-typed personality qualities, academic interests, and school grades. During 7 nightly phone interviews each year, children reported on their activities. Boys were more sex-typed than girls in their peer activities, and children were least sex-typed in their activities with siblings. Sex-typed activities in middle childhood predicted individual differences in gender development in early adolescence. Copyright 2004 American Psychological Association

  7. Evidence for mito-nuclear and sex-linked reproductive barriers between the hybrid Italian sparrow and its parent species.

    Directory of Open Access Journals (Sweden)

    Cassandra N Trier

    2014-01-01

    Full Text Available Studies of reproductive isolation between homoploid hybrid species and their parent species have rarely been carried out. Here we investigate reproductive barriers between a recently recognized hybrid bird species, the Italian sparrow Passer italiae and its parent species, the house sparrow P. domesticus and Spanish sparrow P. hispaniolensis. Reproductive barriers can be difficult to study in hybrid species due to lack of geographical contact between taxa. However, the Italian sparrow lives parapatrically with the house sparrow and both sympatrically and parapatrically with the Spanish sparrow. Through whole-transcriptome sequencing of six individuals of each of the two parent species we identified a set of putatively parent species-diagnostic single nucleotide polymorphism (SNP markers. After filtering for coverage, genotyping success (>97% and multiple SNPs per gene, we retained 86 species-informative, genic, nuclear and mitochondrial SNP markers from 84 genes for analysis of 612 male individuals. We show that a disproportionately large number of sex-linked genes, as well as the mitochondria and nuclear genes with mitochondrial function, exhibit sharp clines at the boundaries between the hybrid and the parent species, suggesting a role for mito-nuclear and sex-linked incompatibilities in forming reproductive barriers. We suggest that genomic conflict via interactions between mitochondria and sex-linked genes with mitochondrial function ("mother's curse" at one boundary and centromeric drive at the other may best explain our findings. Hybrid speciation in the Italian sparrow may therefore be influenced by mechanisms similar to those involved in non-hybrid speciation, but with the formation of two geographically separated species boundaries instead of one. Spanish sparrow alleles at some loci have spread north to form reproductive barriers with house sparrows, while house sparrow alleles at different loci, including some on the same chromosome

  8. Usher syndrome type III (USH3) linked to chromosome 3q in an Italian family.

    Science.gov (United States)

    Gasparini, P; De Fazio, A; Croce, A I; Stanziale, P; Zelante, L

    1998-08-01

    We report an Italian family affected by Usher type III syndrome. Linkage study, performed using markers corresponding to the Usher loci already mapped, clearly showed linkage with markers on chromosome 3q24-25. Our data further support the presence of an Usher III locus on chromosome 3, as recently reported in a Finnish population.

  9. Usher syndrome type III (USH3) linked to chromosome 3q in an Italian family.

    OpenAIRE

    Gasparini, P; De Fazio, A; Croce, A I; Stanziale, P; Zelante, L

    1998-01-01

    We report an Italian family affected by Usher type III syndrome. Linkage study, performed using markers corresponding to the Usher loci already mapped, clearly showed linkage with markers on chromosome 3q24-25. Our data further support the presence of an Usher III locus on chromosome 3, as recently reported in a Finnish population.

  10. Influence of gender constancy and social power on sex-linked modeling.

    Science.gov (United States)

    Bussey, K; Bandura, A

    1984-12-01

    Competing predictions derived from cognitive-developmental theory and social learning theory concerning sex-linked modeling were tested. In cognitive-developmental theory, gender constancy is considered a necessary prerequisite for the emulation of same-sex models, whereas according to social learning theory, sex-role development is promoted through a vast system of social influences with modeling serving as a major conveyor of sex role information. In accord with social learning theory, even children at a lower level of gender conception emulated same-sex models in preference to opposite-sex ones. Level of gender constancy was associated with higher emulation of both male and female models rather than operating as a selective determinant of modeling. This finding corroborates modeling as a basic mechanism in the sex-typing process. In a second experiment we explored the limits of same-sex modeling by pitting social power against the force of collective modeling of different patterns of behavior by male and female models. Social power over activities and rewarding resources produced cross-sex modeling in boys, but not in girls. This unexpected pattern of cross-sex modeling is explained by the differential sex-typing pressures that exist for boys and girls and socialization experiences that heighten the attractiveness of social power for boys.

  11. Modeling and experimental methods to probe the link between global transcription and spatial organization of chromosomes.

    Directory of Open Access Journals (Sweden)

    K Venkatesan Iyer

    Full Text Available Genomes are spatially assembled into chromosome territories (CT within the nucleus of living cells. Recent evidences have suggested associations between three-dimensional organization of CTs and the active gene clusters within neighboring CTs. These gene clusters are part of signaling networks sharing similar transcription factor or other downstream transcription machineries. Hence, presence of such gene clusters of active signaling networks in a cell type may regulate the spatial organization of chromosomes in the nucleus. However, given the probabilistic nature of chromosome positions and complex transcription factor networks (TFNs, quantitative methods to establish their correlation is lacking. In this paper, we use chromosome positions and gene expression profiles in interphase fibroblasts and describe methods to capture the correspondence between their spatial position and expression. In addition, numerical simulations designed to incorporate the interacting TFNs, reveal that the chromosome positions are also optimized for the activity of these networks. These methods were validated for specific chromosome pairs mapped in two distinct transcriptional states of T-Cells (naïve and activated. Taken together, our methods highlight the functional coupling between topology of chromosomes and their respective gene expression patterns.

  12. Chromosome 11-linked determinant controls fetal globin expression and the fetal-to-adult globin switch

    International Nuclear Information System (INIS)

    Melis, M.; Demopulos, G.; Najfeld, V.; Zhang, J.W.; Brice, M.; Papayannopoulou, T.; Stamatoyannopoulos, G.

    1987-01-01

    Hybrids formed by fusing mouse erythroleukemia (MEL) cells with human fetal erythroid cells produce human fetal globin, but they switch to adult globin production as culture time advances. To obtain information on the chromosomal assignment of the elements that control γ-to-β switching, the authors analyzed the chromosomal composition of hybrids producing exclusively or predominantly human fetal globin and hybrids producing only adult human globin. No human chromosome was consistently present in hybrids expressing fetal globin and consistently absent in hybrids expressing adult globin. Subcloning experiments demonstrated identical chromosomal compositions in subclones displaying the fetal globin program and those that had switched to expression of the adult globin program. These data indicate that retention of only one human chromosome -- i.e., chromosome 11 -- is sufficient for expression of human fetal globin and the subsequent γ-to-β switch. The results suggest that the γ-to-β switch is controlled either cis to the β-globin locus of by a trans-acting mechanism, the genes of which reside on human chromosome 11

  13. Enzymatic amplification of a Y chromosome repeat in a single blastomere allows identification of the sex of preimplantation mouse embryos

    International Nuclear Information System (INIS)

    Bradbury, M.W.; Isola, L.M.; Gordon, J.W.

    1990-01-01

    The polymerase chain reaction (PCR) technique has been adapted to identify the sex of preimplantation mouse embryos rapidly. PCR was used to amplify a specific repeated DNA sequence on the Y chromosome from a single isolated blastomere in under 12 hr. The remainder of the biopsied embryo was then transferred to a pseudopregnant female and carried to term. Using this technique, 72% of embryos can be classed as potentially either male or female. Transfers of such embryos have produced pregnancies with 8/8 fetuses (100%) being of the predicted sex. Variations of the technique have demonstrated certain limitations to the present procedure as well as indicated possible strategies for improvement of the assay. The PCR technique may have wide application in the genetic analysis of preimplantation embryos

  14. Meiotic drive on aberrant chromosome 1 in the mouse is determined by a linked distorter.

    Science.gov (United States)

    Agulnik, S I; Sabantsev, I D; Orlova, G V; Ruvinsky, A O

    1993-04-01

    An aberrant chromosome 1 carrying an inverted fragment with two amplified DNA regions was isolated from wild populations of Mus musculus. Meiotic drive favouring the aberrant chromosome was demonstrated for heterozygous females. Its cause was preferential passage of aberrant chromosome 1 to the oocyte. Genetic analysis allowed us to identify a two-component system conditioning deviation from equal segregation of the homologues. The system consists of a postulated distorter and responder. The distorter is located on chromosome 1 distally to the responder, between the ln and Pep-3 genes, and it acts on the responder when in trans position. Polymorphism of the distorters was manifested as variation in their effect on meiotic drive level in the laboratory strain and mice from wild populations.

  15. Linking Y‐chromosomal short tandem repeat loci to human male impulsive aggression

    OpenAIRE

    Yang, Chun; Ba, Huajie; Cao, Yin; Dong, Guoying; Zhang, Shuyou; Gao, Zhiqin; Zhao, Hanqing; Zhou, Xianju

    2017-01-01

    Abstract Introduction Men are more susceptible to impulsive behavior than women. Epidemiological studies revealed that the impulsive aggressive behavior is affected by genetic factors, and the male‐specific Y chromosome plays an important role in this behavior. In this study, we investigated the association between the impulsive aggressive behavior and Y‐chromosomal short tandem repeats (Y‐STRs) loci. Methods The collected biologic samples from 271 offenders with impulsive aggressive behavior...

  16. MK17, a specific marker closely linked to the gynoecium suppression region on the Y chromosome in Silene latifolia

    Czech Academy of Sciences Publication Activity Database

    Hobza, Roman; Hrušáková, P.; Šafář, Jan; Bartoš, Jan; Janoušek, Bohuslav; Žlůvová, Jitka; Michu, Elleni; Doležel, Jaroslav; Vyskot, Boris

    2006-01-01

    Roč. 113, č. 2 (2006), s. 280-287 ISSN 0040-5752 R&D Projects: GA ČR(CZ) GA521/06/0056; GA ČR(CZ) GD204/05/H505; GA ČR(CZ) GA521/05/2076; GA AV ČR(CZ) 1QS500040507 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50380511 Keywords : sex chromosomes * melandrium-album * evolution Subject RIV: BO - Biophysics Impact factor: 2.715, year: 2006

  17. A new approach to chromosome-wide analysis of X-linked markers identifies new associations in Asian and European case-parent triads of orofacial clefts.

    Directory of Open Access Journals (Sweden)

    Øivind Skare

    Full Text Available GWAS discoveries on the X-chromosome are underrepresented in the literature primarily because the analytical tools that have been applied were originally designed for autosomal markers. Our objective here is to employ a new robust and flexible tool for chromosome-wide analysis of X-linked markers in complex traits. Orofacial clefts are good candidates for such analysis because of the consistently observed excess of females with cleft palate only (CPO and excess of males with cleft lip with or without cleft palate (CL/P.Genotypes for 14,486 X-chromosome SNPs in 1,291 Asian and 1,118 European isolated cleft triads were available from a previously published GWAS. The R-package HAPLIN enables genome-wide-level analyses as well as statistical power simulations for a range of biologic scenarios. We analyzed isolated CL/P and isolated CPO for each ethnicity in HAPLIN, using a sliding-window approach to haplotype analysis and two different statistical models, with and without X-inactivation in females.There was a larger number of associations in the Asian versus the European sample, and similar to previous reports that have analyzed the same GWAS dataset using different methods, we identified associations with EFNB1/PJA1 and DMD. In addition, new associations were detected with several other genes, among which KLHL4, TBX22, CPXCR1 and BCOR were noteworthy because of their roles in clefting syndromes. A few of the associations were only detected by one particular X-inactivation model, whereas a few others were only detected in one sex.We found new support for the involvement of X-linked variants in isolated clefts. The associations were specific for ethnicity, sex and model parameterization, highlighting the need for flexible tools that are capable of detecting and estimating such effects. Further efforts are needed to verify and elucidate the potential roles of EFNB1/PJA1, KLHL4, TBX22, CPXCR1 and BCOR in isolated clefts.

  18. Sex determination using free fetal DNA in early pregnancy: With the approach to sex linked recessive disorders

    Directory of Open Access Journals (Sweden)

    Amir Monfaredan

    2017-03-01

    Full Text Available Introduction: Prenatal diagnosis is testing for detection of diseases or conditions in a fetus or embryo before it is born. Most of prenatal diagnostic (PD techniques are invasive and done in late stages of pregnancy. Using fetal DNA in maternal blood for fetal sex determination in early pregnancy might help in management of X-linked genetic diseases. This study aimed to investigate the accuracy of sex determination using fetal DNA in maternal blood at 8-12 weeks of gestation. Methods: In this cross-sectional study, 30 pregnant women at 8-12 weeks of gestation were enrolled. The sex-determining region Y (SRY gene expression with the internal control (IC glyceraldehyde 3-phosphate dehydrogenase (GAPDH was investigated with quantitative real-time polymerase chain reaction (PCR using specific primers and probes. Results: Accuracy of sex determination with SRY gene expression in 8-12 weeks of pregnancy were 85%, 85%, 90% and 100% respectively. Conclusion: It seems that fetal sex determining using fetal DNA in maternal blood is a reliable method for early stage of pregnancy.

  19. Targeted resequencing of the pericentromere of chromosome 2 linked to constitutional delay of growth and puberty.

    Directory of Open Access Journals (Sweden)

    Diana L Cousminer

    Full Text Available Constitutional delay of growth and puberty (CDGP is the most common cause of pubertal delay. CDGP is defined as the proportion of the normal population who experience pubertal onset at least 2 SD later than the population mean, representing 2.3% of all adolescents. While adolescents with CDGP spontaneously enter puberty, they are at risk for short stature, decreased bone mineral density, and psychosocial problems. Genetic factors contribute heavily to the timing of puberty, but the vast majority of CDGP cases remain biologically unexplained, and there is no definitive test to distinguish CDGP from pathological absence of puberty during adolescence. Recently, we published a study identifying significant linkage between a locus at the pericentromeric region of chromosome 2 (chr 2 and CDGP in Finnish families. To investigate this region for causal variation, we sequenced chr 2 between the genomic coordinates of 79-124 Mb (genome build GRCh37 in the proband and affected parent of the 13 families contributing most to this linkage signal. One gene, DNAH6, harbored 6 protein-altering low-frequency variants (< 6% in the Finnish population in 10 of the CDGP probands. We sequenced an additional 135 unrelated Finnish CDGP subjects and utilized the unique Sequencing Initiative Suomi (SISu population reference exome set to show that while 5 of these variants were present in the CDGP set, they were also present in the Finnish population at similar frequencies. Additional variants in the targeted region could not be prioritized for follow-up, possibly due to gaps in sequencing coverage or lack of functional knowledge of non-genic genomic regions. Thus, despite having a well-characterized sample collection from a genetically homogeneous population with a large population-based reference sequence dataset, we were unable to pinpoint variation in the linked region predisposing delayed puberty. This study highlights the difficulties of detecting genetic variants

  20. A new species of Endecous Saussure, 1878 (Orthoptera, Gryllidae) from northeast Brazil with the first X1X20 chromosomal sex system in Gryllidae.

    Science.gov (United States)

    Zefa, Edison; Redü, Darlan Rutz; Da Costa, Maria Kátia Matiotti; Fontanetti, Carmem S; Gottschalk, Marco Silva; Padilha, Giovanna Boff; Fernandes e Silva, Anelise; Martins, Luciano De P

    2014-08-06

    In this paper we describe a new species of Luzarinae cricket collected from the cave "Gruta de Ubajara, municipality of Ubajara, State of Ceará, Brazil, highlighting phallic sclerites morphology and chromosome complement as diagnostic characters. We presented meiotic and mitotic characterization in order to define the karyotype with 2n = 12 + X1X2♂/12 + X1X1X2X2♀. This represents the first record of X1X20 chromosomal sex system in Gryllidae.

  1. Sex comb on midleg (Scm) is a functional link between PcG-repressive complexes in Drosophila.

    Science.gov (United States)

    Kang, Hyuckjoon; McElroy, Kyle A; Jung, Youngsook Lucy; Alekseyenko, Artyom A; Zee, Barry M; Park, Peter J; Kuroda, Mitzi I

    2015-06-01

    The Polycomb group (PcG) proteins are key regulators of development in Drosophila and are strongly implicated in human health and disease. How PcG complexes form repressive chromatin domains remains unclear. Using cross-linked affinity purifications of BioTAP-Polycomb (Pc) or BioTAP-Enhancer of zeste [E(z)], we captured all PcG-repressive complex 1 (PRC1) or PRC2 core components and Sex comb on midleg (Scm) as the only protein strongly enriched with both complexes. Although previously not linked to PRC2, we confirmed direct binding of Scm and PRC2 using recombinant protein expression and colocalization of Scm with PRC1, PRC2, and H3K27me3 in embryos and cultured cells using ChIP-seq (chromatin immunoprecipitation [ChIP] combined with deep sequencing). Furthermore, we found that RNAi knockdown of Scm and overexpression of the dominant-negative Scm-SAM (sterile α motif) domain both affected the binding pattern of E(z) on polytene chromosomes. Aberrant localization of the Scm-SAM domain in long contiguous regions on polytene chromosomes revealed its independent ability to spread on chromatin, consistent with its previously described ability to oligomerize in vitro. Pull-downs of BioTAP-Scm captured PRC1 and PRC2 and additional repressive complexes, including PhoRC, LINT, and CtBP. We propose that Scm is a key mediator connecting PRC1, PRC2, and transcriptional silencing. Combined with previous structural and genetic analyses, our results strongly suggest that Scm coordinates PcG complexes and polymerizes to produce broad domains of PcG silencing. © 2015 Kang et al.; Published by Cold Spring Harbor Laboratory Press.

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

    Czech Academy of Sciences Publication Activity Database

    Drosopoulou, E.; Nakou, I.; Šíchová, Jindra; Kubíčková, S.; Marec, František; Mavragani-Tsipidou, P.

    2012-01-01

    Roč. 140, 4-6 (2012), s. 169-180 ISSN 0016-6707 R&D Projects: GA AV ČR IAA600960925 Grant - others:Ministry of Agriculture of the Czech Republic(CZ) MZE 0002716202; Grant Agency of the University of South Bohemia(CZ) GAJU 137/2010/P Institutional support: RVO:60077344 Keywords : chromosome painting * FISH * laser microdissection Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.681, year: 2012 http://link.springer.com/article/10.1007/s10709-012-9668-3

  3. Structure and evolution of Apetala3, a sex-linked gene in Silene latifolia

    Czech Academy of Sciences Publication Activity Database

    Čegan, Radim; Marais, G.A.B.; Kubeková, Hana; Blavet, N.; Widmer, A.; Vyskot, Boris; Doležel, Jaroslav; Šafář, Jan; Hobza, Roman

    2010-01-01

    Roč. 10, č. 180 (2010), s. 1-10 ISSN 1471-2229 R&D Projects: GA ČR(CZ) GA522/09/0083; GA ČR(CZ) GD204/09/H002; GA AV ČR(CZ) KJB600040901 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702; CEZ:AV0Z50380511 Keywords : sex chromosomes evolution * Apetala3 * Silene Subject RIV: BO - Biophysics Impact factor: 4.085, year: 2010

  4. Mutational analysis of the Wolfram syndrome gene in two families with chromosome 4p-linked bipolar affective disorder.

    Science.gov (United States)

    Evans, K L; Lawson, D; Meitinger, T; Blackwood, D H; Porteous, D J

    2000-04-03

    Bipolar affective disorder (BPAD) is a complex disease with a significant genetic component. Heterozygous carriers of Wolfram syndrome (WFS) are at increased risk of psychiatric illness. A gene for WFS (WFS1) has recently been cloned and mapped to chromosome 4p, in the general region we previously reported as showing linkage to BPAD. Here we present sequence analysis of the WFS1 coding sequence in five affected individuals from two chromosome 4p-linked families. This resulted in the identification of six polymorphisms, two of which are predicted to change the amino acid sequence of the WFS1 protein, however none of the changes segregated with disease status. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:158-160, 2000. Copyright 2000 Wiley-Liss, Inc.

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

    Czech Academy of Sciences Publication Activity Database

    Vrbová, Iva; Traut, W.; Vítková, Magda; Nguyen, Petr; Kubíčková, S.; Marec, František

    2007-01-01

    Roč. 116, č. 2, (2007), s. 135-145 ISSN 0009-5915 R&D Projects: GA ČR(CZ) GA206/06/1860; GA ČR GD521/03/H160; GA AV ČR IAA6007307 Grant - others:International Atomic Energy Agency(AT) 12055/R Institutional research plan: CEZ:AV0Z50070508 Keywords : W chromosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.337, year: 2007

  6. Normal Female Germ Cell Differentiation Requires the Female X Chromosome to Autosome Ratio and Expression of Sex-Lethal in DROSOPHILA MELANOGASTER

    OpenAIRE

    Schüpbach, Trudi

    1985-01-01

    In somatic cells of Drosophila, the ratio of X chromosomes to autosomes (X:A ratio) determines sex and dosage compensation. The present paper addresses the question of whether germ cells also use the X:A ratio for sex determination and dosage compensation. Triploid female embryos were generated which, through the loss of an unstable ring-X chromosome, contained some germ cells of 2X;3A constitution in their ovaries. Such germ cells were shown to differentiate along one of two alternative pat...

  7. Cytogenetics of the Javan file snake (Acrochordus javanicus) and the evolution of snake sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Altmanová, Marie; Johnson Pokorná, Martina; Augstenová, B.; Kratochvíl, L.

    2018-01-01

    Roč. 56, č. 1 (2018), s. 117-125 ISSN 0947-5745 Institutional support: RVO:67985904 Keywords : GATA * genome organization * sex determination Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.444, year: 2016

  8. Haplotype analysis and a novel allele-sharing method refines a chromosome 4p locus linked to bipolar affective disorder.

    Science.gov (United States)

    Le Hellard, Stephanie; Lee, Andrew J; Underwood, Sarah; Thomson, Pippa A; Morris, Stewart W; Torrance, Helen S; Anderson, Susan M; Adams, Richard R; Navarro, Pau; Christoforou, Andrea; Houlihan, Lorna M; Detera-Wadleigh, Sevilla; Owen, Michael J; Asherson, Philip; Muir, Walter J; Blackwood, Douglas H R; Wray, Naomi R; Porteous, David J; Evans, Kathryn L

    2007-03-15

    Bipolar affective disorder (BPAD) and schizophrenia (SCZ) are common conditions. Their causes are unknown, but they include a substantial genetic component. Previously, we described significant linkage of BPAD to a chromosome 4p locus within a large pedigree (F22). Others subsequently have found evidence for linkage of BPAD and SCZ to this region. We constructed high-resolution haplotypes for four linked families, calculated logarithm of the odds (LOD) scores, and developed a novel method to assess the extent of allele sharing within genes between the families. We describe an increase in the F22 LOD score for this region. Definition and comparison of the linked haplotypes allowed us to prioritize two subregions of 3.8 and 4.4 Mb. Analysis of the extent of allele sharing within these subregions identified 200 kb that shows increased allele sharing between families. Linkage of BPAD to chromosome 4p has been strengthened. Haplotype analysis in the additional linked families refined the 20-Mb linkage region. Development of a novel allele-sharing method allowed us to bridge the gap between conventional linkage and association studies. Description of a 200-kb region of increased allele sharing prioritizes this region, which contains two functional candidate genes for BPAD, SLC2A9, and WDR1, for subsequent studies.

  9. Inherent X-Linked Genetic Variability and Cellular Mosaicism Unique to Females Contribute to Sex-Related Differences in the Innate Immune Response

    Directory of Open Access Journals (Sweden)

    Zoltan Spolarics

    2017-11-01

    Full Text Available Females have a longer lifespan and better general health than males. Considerable number of studies also demonstrated that, after trauma and sepsis, females present better outcomes as compared to males indicating sex-related differences in the innate immune response. The current notion is that differences in the immuno-modulatory effects of sex hormones are the underlying causative mechanism. However, the field remains controversial and the exclusive role of sex hormones has been challenged. Here, we propose that polymorphic X-linked immune competent genes, which are abundant in the population are important players in sex-based immuno-modulation and play a key role in causing sex-related outcome differences following trauma or sepsis. We describe the differences in X chromosome (ChrX regulation between males and females and its consequences in the context of common X-linked polymorphisms at the individual as well as population level. We also discuss the potential pathophysiological and immune-modulatory aspects of ChrX cellular mosaicism, which is unique to females and how this may contribute to sex-biased immune-modulation. The potential confounding effects of ChrX skewing of cell progenitors at the bone marrow is also presented together with aspects of acute trauma-induced de novo ChrX skewing at the periphery. In support of the hypothesis, novel observations indicating ChrX skewing in a female trauma cohort as well as case studies depicting the temporal relationship between trauma-induced cellular skewing and the clinical course are also described. Finally, we list and discuss a selected set of polymorphic X-linked genes, which are frequent in the population and have key regulatory or metabolic functions in the innate immune response and, therefore, are primary candidates for mediating sex-biased immune responses. We conclude that sex-related differences in a variety of disease processes including the innate inflammatory response to injury

  10. Mutagenic Potential of Nitroguanidine in the Drosophila melanogaster Sex-Linked Recessive Lethal Test

    Science.gov (United States)

    1988-07-01

    Security Classification) Mtutagenic potential of nitroguan idine in the Drosophila melano- gaster sex-linked recessive lethal test 12. PERSONAL AUTHOR(S...Frederick, MD 21701-5012 Commander Commandant US Army Environmental Hygine Academy of Health Sciences. US Army Agency ATTN: AHS-CDM ATTN: Librarian, HSDH

  11. Preliminary Evidence for an Automatic Link between Sex and Power among Men Who Molest Children

    Science.gov (United States)

    Kamphuis, Jan H.; De Ruiter, Corine; Janssen, Bas; Spiering, Mark

    2005-01-01

    Understanding critical motivational processes of sexual offenders may ultimately provide important clues to more effective treatments. Implicit, automatic cognitive processes have received minimal attention; however, a lexical decision experiment revealed automatic links between the concepts of power and sex among participants who self-reported…

  12. Marfan syndrome is closely linked to a marker on chromosome 15q1. 5 r arrow q2. 1

    Energy Technology Data Exchange (ETDEWEB)

    Tsipouras, P.; Sarfarazi, M.; Devi, A. (Univ. of Connecticut Health Center, Farmington (United States)); Weiffenbach, B. (Collaborative Research, Inc., Waltham, MA (United States)); Boxer, M. (Ninewells Hospital and Medical School, Dundee (Scotland))

    1991-05-15

    Marfan syndrome is a systemic disorder of the connective tissue inherited as an autosomal dominant trait. The disorder imparts significant morbidity and martality. The etiology of the disorder remains elusive. A recent study localized the gene for Marfan syndrome on chromosome 15. The authors present data showing that marker D15S48 is genetically linked to Marfan syndrome. Pairwise linkage analysis gave a maximum lod (logarithm of odds) score of Z = 11.78 at {theta} = 0.02. Furthermore our data suggest that the Marfan syndrome locus is possibly flanked on either side by D15S48 and D15S49.

  13. Linking Temperamental Shyness and Social Anxiety in Childhood and Adolescence: Moderating Influences of Sex and Age.

    Science.gov (United States)

    Tsui, Tiffany Y L; Lahat, Ayelet; Schmidt, Louis A

    2017-10-01

    Although childhood shyness has been linked to social anxiety problems, the factors playing a role in this association have gone largely unexplored. Here we examined the potential moderating roles of sex and age on this relation in a sample of 119 (75 girls) children (10-12 years) and adolescents (14-16 years). As predicted, shyness was positively associated with social anxiety symptoms. Sex, but not age, served as a moderating factor in linking shyness and social anxiety. Specifically, shyness was more strongly associated with social anxiety symptoms among girls than boys. These results suggest the importance of considering sex differences when examining the relation between shyness and social anxiety in childhood and adolescence.

  14. Evolution of karyotype, sex chromosomes, and meiosis in mygalomorph spiders (Araneae: Mygalomorphae)

    Czech Academy of Sciences Publication Activity Database

    Král, J.; Kořínková, T.; Krkavcová, L.; Musilová, J.; Forman, M.; Ávila Herrera, I. M.; Haddad, C. R.; Vítková, Magda; Henriques, S.; Palacios Vargas, J. G.; Hedin, M.

    2013-01-01

    Roč. 109, č. 2 (2013), s. 377-408 ISSN 0024-4066 Grant - others:AV ČR(CZ) IAA601110808; GA ČR(CZ) GA206/08/0813; Univerzita Karlova v Praze(CZ) SVV-2013-267205; Univerzita Karlova v Praze(CZ) SVV-2012-265202 Institutional support: RVO:60077344 Keywords : achiasmatic * chromosome pairing * deactivation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.535, year: 2013 http://onlinelibrary.wiley.com/doi/10.1111/bij.12056/pdf

  15. Phylogenomics of a rapid radiation: is chromosomal evolution linked to increased diversification in north american spiny lizards (Genus Sceloporus)?

    Science.gov (United States)

    Leaché, Adam D; Banbury, Barbara L; Linkem, Charles W; de Oca, Adrián Nieto-Montes

    2016-03-22

    Resolving the short phylogenetic branches that result from rapid evolutionary diversification often requires large numbers of loci. We collected targeted sequence capture data from 585 nuclear loci (541 ultraconserved elements and 44 protein-coding genes) to estimate the phylogenetic relationships among iguanian lizards in the North American genus Sceloporus. We tested for diversification rate shifts to determine if rapid radiation in the genus is correlated with chromosomal evolution. The phylogenomic trees that we obtained for Sceloporus using concatenation and coalescent-based species tree inference provide strong support for the monophyly and interrelationships among nearly all major groups. The diversification analysis supported one rate shift on the Sceloporus phylogeny approximately 20-25 million years ago that is associated with the doubling of the speciation rate from 0.06 species/million years (Ma) to 0.15 species/Ma. The posterior probability for this rate shift occurring on the branch leading to the Sceloporus species groups exhibiting increased chromosomal diversity is high (posterior probability = 0.997). Despite high levels of gene tree discordance, we were able to estimate a phylogenomic tree for Sceloporus that solves some of the taxonomic problems caused by previous analyses of fewer loci. The taxonomic changes that we propose using this new phylogenomic tree help clarify the number and composition of the major species groups in the genus. Our study provides new evidence for a putative link between chromosomal evolution and the rapid divergence and radiation of Sceloporus across North America.

  16. Abnormal sex chromosome constitution and longitudinal growth: serum levels of insulin-like growth factor (IGF)-I, IGF binding protein-3, luteinizing hormone, and testosterone in 109 males with 47,XXY, 47,XYY, or sex-determining region of the Y chromosome (SRY)-positive 46,XX karyotypes

    DEFF Research Database (Denmark)

    Aksglaede, L.; Skakkebaek, N.E.; Juul, A.

    2008-01-01

    CONTEXT: Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles. AIM: The aim of the study was to evaluate the role of abnormal chromosome constitution...... and elevated LH levels after puberty, whereas the sex hormone secretion of the 47,XYY boys remained normal. CONCLUSION: We found accelerated growth in early childhood in boys with 47,XXY and 47,XYY karyotypes, whereas 46,XX-males were shorter than controls. These abnormal growth patterns were not reflected...

  17. Machado-Joseph Disease in Pedigrees of Azorean descent is Linked to Chromosome 14

    OpenAIRE

    George-Hyslop, P. St; Rogaeva, E.; Huterer, J.; Tsuda, T.; Santos, J.; Haines, J. L.; Schlumpf, K.; Rogaev, E. I.; Liang, Y.; McLachlan, D. R. Crapper; Kennedy, J.; Weissenbach, J.; Billingsley, G. D.; Cox, D. W.; Lang, A. E.

    1994-01-01

    A locus for Machado-Joseph disease (MJD) has recently been mapped to a 30-cM region of chromosome 14q in five pedigrees of Japanese descent. MJD is a clinically pleomorphic neurodegenerative disease that was originally described in subjects of Azorean descent. In light of the nonallelic heterogeneity in other inherited spinocere-bellar ataxias, we were interested to determine if the MJD phenotype in Japanese and Azorean pedigrees arose from mutations at the same locus. We provide evidence tha...

  18. Sex chromosome-linked species recognition and evolution of reproductive isolation in flycatchers

    NARCIS (Netherlands)

    Saether, Stein A.; Saetre, Glenn-Peter; Borge, Thomas; Wiley, Chris; Svedin, Nina; Andersson, Gunilla; Veen, Thor; Haavie, Jon; Servedio, Maria R.; Bures, Stanislav; Kral, Miroslav; Hjernquist, Marten B.; Gustafsson, Lars; Traeff, Johan; Qvarnstroem, Anna

    2007-01-01

    Interbreeding between species (hybridization) typically produces unfit offspring. Reduced hybridization should therefore be favored by natural selection. However, this is difficult to accomplish because hybridization also sets the stage for genetic recombination to dissociate species-specific traits

  19. An anther- and petal-specific gene SlMF1 is a multicopy gene with homologous sequences on sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Matsunaga, S.; Lebel-Hardenack, S.; Kejnovský, Eduard; Vyskot, Boris; Grant, Sarah R.; Kawano, S.

    2005-01-01

    Roč. 80, - (2005), s. 395-401 ISSN 1341-7568 R&D Projects: GA ČR(CZ) GA204/05/2097 Institutional research plan: CEZ:AV0Z50040507 Keywords : dioecious plant * male flower * sex chromosomes Subject RIV: BO - Biophysics Impact factor: 1.081, year: 2005

  20. Exposure to persistent organic pollutants and sperm sex chromosome ratio in men from the Faroe Islands

    DEFF Research Database (Denmark)

    Kvist, L; Giwercman, A; Weihe, P

    2014-01-01

    People in the Arctic as well as fishermen on the polluted Swedish east coast are highly exposed to persistent organic pollutants (POPs). These compounds have been shown to affect the sperm Y:X chromosome ratio. In present study, the aim was to investigate whether polychlorinated biphenyl (PCB......,p'-DDE and ΣPCB correlated significantly (r=0.927, pboth Inuit and Swedish fishermen (0.512 for both......). In conclusion, Faroese men presented with lower Y:X ratio than Greenland Inuit and Swedish fishermen. Although no direct health effects are expected due to the lower Faroese Y:X ratio, it could be indicative of adverse effects on the reproductive system....

  1. A sex-chromosome inversion causes strong overdominance for sperm traits that affect siring success.

    Science.gov (United States)

    Knief, Ulrich; Forstmeier, Wolfgang; Pei, Yifan; Ihle, Malika; Wang, Daiping; Martin, Katrin; Opatová, Pavlína; Albrechtová, Jana; Wittig, Michael; Franke, Andre; Albrecht, Tomáš; Kempenaers, Bart

    2017-08-01

    Male reproductive success depends on the competitive ability of sperm to fertilize the ova, which should lead to strong selection on sperm characteristics. This raises the question of how heritable variation in sperm traits is maintained. Here we show that in zebra finches (Taeniopygia guttata) nearly half of the variance in sperm morphology is explained by an inversion on the Z chromosome with a 40% allele frequency in the wild. The sperm of males that are heterozygous for the inversion had the longest midpieces and the highest velocity. Furthermore, such males achieved the highest fertility and the highest siring success, both within-pair and extra-pair. Males homozygous for the derived allele show detrimental sperm characteristics and the lowest siring success. Our results suggest heterozygote advantage as the mechanism that maintains the inversion polymorphism and hence variance in sperm design and in fitness.

  2. Regulatory cross-talk links Vibrio cholerae chromosome II replication and segregation.

    Directory of Open Access Journals (Sweden)

    Yoshiharu Yamaichi

    2011-07-01

    Full Text Available There is little knowledge of factors and mechanisms for coordinating bacterial chromosome replication and segregation. Previous studies have revealed that genes (and their products that surround the origin of replication (oriCII of Vibrio cholerae chromosome II (chrII are critical for controlling the replication and segregation of this chromosome. rctB, which flanks one side of oriCII, encodes a protein that initiates chrII replication; rctA, which flanks the other side of oriCII, inhibits rctB activity. The chrII parAB2 operon, which is essential for chrII partitioning, is located immediately downstream of rctA. Here, we explored how rctA exerts negative control over chrII replication. Our observations suggest that RctB has at least two DNA binding domains--one for binding to oriCII and initiating replication and the other for binding to rctA and thereby inhibiting RctB's ability to initiate replication. Notably, the inhibitory effect of rctA could be alleviated by binding of ParB2 to a centromere-like parS site within rctA. Furthermore, by binding to rctA, ParB2 and RctB inversely regulate expression of the parAB2 genes. Together, our findings suggest that fluctuations in binding of the partitioning protein ParB2 and the chrII initiator RctB to rctA underlie a regulatory network controlling both oriCII firing and the production of the essential chrII partitioning proteins. Thus, by binding both RctB and ParB2, rctA serves as a nexus for regulatory cross-talk coordinating chrII replication and segregation.

  3. Roles of the Y chromosome genes in human cancers

    Directory of Open Access Journals (Sweden)

    Tatsuo Kido

    2015-06-01

    Full Text Available Male and female differ genetically by their respective sex chromosome composition, that is, XY as male and XX as female. Although both X and Y chromosomes evolved from the same ancestor pair of autosomes, the Y chromosome harbors male-specific genes, which play pivotal roles in male sex determination, germ cell differentiation, and masculinization of various tissues. Deletions or translocation of the sex-determining gene, SRY, from the Y chromosome causes disorders of sex development (previously termed as an intersex condition with dysgenic gonads. Failure of gonadal development results not only in infertility, but also in increased risks of germ cell tumor (GCT, such as gonadoblastoma and various types of testicular GCT. Recent studies demonstrate that either loss of Y chromosome or ectopic expression of Y chromosome genes is closely associated with various male-biased diseases, including selected somatic cancers. These observations suggest that the Y-linked genes are involved in male health and diseases in more frequently than expected. Although only a small number of protein-coding genes are present in the male-specific region of Y chromosome, the impacts of Y chromosome genes on human diseases are still largely unknown, due to lack of in vivo models and differences between the Y chromosomes of human and rodents. In this review, we highlight the involvement of selected Y chromosome genes in cancer development in men.

  4. Popularity among Same-Sex and Cross-Sex Peers: A Process-Oriented Examination of Links to Aggressive Behaviors and Depressive Affect

    Science.gov (United States)

    Troop-Gordon, Wendy; Ranney, John D.

    2014-01-01

    Popularity has been linked to heightened aggression and fewer depressive symptoms. The current study extends this literature by examining the unique contributions of same-sex and cross-sex popularity to children's development, as well as potential mediating processes. Third- and 4th-graders (212 boys, 250 girls) provided data at 3 time points over…

  5. The eXtraordinarY Kids Clinic: an interdisciplinary model of care for children and adolescents with sex chromosome aneuploidy

    Directory of Open Access Journals (Sweden)

    Tartaglia N

    2015-07-01

    Full Text Available Nicole Tartaglia,1,2 Susan Howell,1,2 Rebecca Wilson,2 Jennifer Janusz,1,2 Richard Boada,1,2 Sydney Martin,2 Jacqueline B Frazier,2 Michelle Pfeiffer,2 Karen Regan,2 Sarah McSwegin,2 Philip Zeitler1,2 1Department of Pediatrics, University of Colorado School of Medicine, 2Child Development Unit, Children's Hospital Colorado, Aurora, CO, USA Purpose: Individuals with sex chromosome aneuploidies (SCAs are born with an atypical number of X and/or Y chromosomes, and present with a range of medical, developmental, educational, behavioral, and psychological concerns. Rates of SCA diagnoses in infants and children are increasing, and there is a need for specialized interdisciplinary care to address associated risks. The eXtraordinarY Kids Clinic was established to provide comprehensive and experienced care for children and adolescents with SCA, with an interdisciplinary team composed of developmental–behavioral pediatrics, endocrinology, genetic counseling, child psychology, pediatric neuropsychology, speech–language pathology, occupational therapy, nursing, and social work. The clinic model includes an interdisciplinary approach to care, where assessment results by each discipline are integrated to develop unified diagnostic impressions and treatment plans individualized for each patient. Additional objectives of the eXtraordinarY Kids Clinic program include prenatal genetic counseling, research, education, family support, and advocacy. Methods: Satisfaction surveys were distributed to 496 patients, and responses were received from 168 unique patients. Results: Satisfaction with the overall clinic visit was ranked as “very satisfied” in 85%, and as “satisfied” in another 9.8%. Results further demonstrate specific benefits from the clinic experience, the importance of a knowledgeable clinic coordinator, and support the need for similar clinics across the country. Three case examples of the interdisciplinary approach to assessment and

  6. Modification of radiation-induced sex-linked recessive lethal mutation frequency by tocopherol

    International Nuclear Information System (INIS)

    Beckman, C.; Roy, R.M.; Sproule, A.

    1982-01-01

    The present study evaluates the effect of supplementing culture medium with α-tocopherol acetate on the yield of sex-linked recessive lethal mutants induced by X-irradiation in mature sperm of Drosophila. Although tocopherol treatment of males had no impact on the yield of mutations, a drastic reduction in mutation frequency was observed when irradiated males were mated to females raised and subsequently maintained on tocopherol-enriched diet. (orig./MG)

  7. X- and Y-chromosome specific variants of the amelogenin gene allow sex determination in sheep (Ovis aries and European red deer (Cervus elaphus

    Directory of Open Access Journals (Sweden)

    Brenig B

    2005-03-01

    Full Text Available Abstract Background Simple and precise methods for sex determination in animals are a pre-requisite for a number of applications in animal production and forensics. However, some of the existing methods depend only on the detection of Y-chromosome specific sequences. Therefore, the abscence of a signal does not necessarily mean that the sample is of female origin, because experimental errors can also lead to negative results. Thus, the detection of Y- and X-chromosome specific sequences is advantageous. Results A novel method for sex identification in mammals (sheep, Ovis aries and European red deer, Cervus elaphus is described, using a polymerase chain reaction (PCR and sequencing of a part of the amelogenin gene. A partial sequence of the amelogenin gene of sheep and red deer was obtained, which exists on both X and Y chromosomes with a deletion region on the Y chromosome. With a specific pair of primers a DNA fragment of different length between the male and female mammal was amplified. Conclusion PCR amplification using the amelogenin gene primers is useful in sex identification of samples from sheep and red deer and can be applied to DNA analysis of micro samples with small amounts of DNA such as hair roots as well as bones or embryo biopsies.

  8. SRY mutation analysis by next generation (deep sequencing in a cohort of chromosomal Disorders of Sex Development (DSD patients with a mosaic karyotype

    Directory of Open Access Journals (Sweden)

    Hersmus Remko

    2012-11-01

    Full Text Available Abstract Background The presence of the Y-chromosome or Y chromosome-derived material is seen in 4-60% of Turner syndrome patients (Chromosomal Disorders of Sex Development (DSD. DSD patients with specific Y-chromosomal material in their karyotype, the GonadoBlastoma on the Y-chromosome (GBY region, have an increased risk of developing type II germ cell tumors/cancer (GCC, most likely related to TSPY. The Sex determining Region on the Y gene (SRY is located on the short arm of the Y-chromosome and is the crucial switch that initiates testis determination and subsequent male development. Mutations in this gene are responsible for sex reversal in approximately 10-15% of 46,XY pure gonadal dysgenesis (46,XY DSD cases. The majority of the mutations described are located in the central HMG domain, which is involved in the binding and bending of the DNA and harbors two nuclear localization signals. SRY mutations have also been found in a small number of patients with a 45,X/46,XY karyotype and might play a role in the maldevelopment of the gonads. Methods To thoroughly investigate the presence of possible SRY gene mutations in mosaic DSD patients, we performed next generation (deep sequencing on the genomic DNA of fourteen independent patients (twelve 45,X/46,XY, one 45,X/46,XX/46,XY, and one 46,XX/46,XY. Results and conclusions The results demonstrate that aberrations in SRY are rare in mosaic DSD patients and therefore do not play a significant role in the etiology of the disease.

  9. The mating type locus (MAT and sexual reproduction of Cryptococcus heveanensis: insights into the evolution of sex and sex-determining chromosomal regions in fungi.

    Directory of Open Access Journals (Sweden)

    Banu Metin

    2010-05-01

    transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  11. Reliving emotional personal memories: affective biases linked to personality and sex-related differences.

    Science.gov (United States)

    Denkova, Ekaterina; Dolcos, Sanda; Dolcos, Florin

    2012-06-01

    Although available evidence suggests that the emotional valence and recollective properties of autobiographical memories (AMs) may be influenced by personality- and sex-related differences, overall these relationships remain poorly understood. The present study investigated these issues by comparing the effect of general personality traits (extraversion and neuroticism) and specific traits linked to emotion regulation (ER) strategies (reappraisal and suppression) on the retrieval of emotional AMs and on the associated postretrieval emotional states, in men and women. First, extraversion predicted recollection of positive AMs in both men and women, whereas neuroticism predicted the proportion of negative AMs in men and the frequency of rehearsing negative AMs in women. Second, reappraisal predicted positive AMs in men, and suppression predicted negative AMs in women. Third, while reliving of positive memories had an overall indirect effect on postretrieval positive mood through extraversion, reliving of negative AMs had a direct effect on postretrieval negative mood, which was linked to inefficient engagement of suppression in women. Our findings suggest that personality traits associated with positive affect predict recollection of positive AMs and maintenance of a positive mood, whereas personality traits associated with negative affect, along with differential engagement of habitual ER strategies in men and women, predict sex-related differences in the recollection and experiencing of negative AMs. These findings provide insight into the factors that influence affective biases in reliving AMs, and into their possible link to sex-related differences in the susceptibility to affective disorders.

  12. Purifying Selection Maintains Dosage-Sensitive Genes during Degeneration of the Threespine Stickleback Y Chromosome

    Science.gov (United States)

    White, Michael A.; Kitano, Jun; Peichel, Catherine L.

    2015-01-01

    Sex chromosomes are subject to unique evolutionary forces that cause suppression of recombination, leading to sequence degeneration and the formation of heteromorphic chromosome pairs (i.e., XY or ZW). Although progress has been made in characterizing the outcomes of these evolutionary processes on vertebrate sex chromosomes, it is still unclear how recombination suppression and sequence divergence typically occur and how gene dosage imbalances are resolved in the heterogametic sex. The threespine stickleback fish (Gasterosteus aculeatus) is a powerful model system to explore vertebrate sex chromosome evolution, as it possesses an XY sex chromosome pair at relatively early stages of differentiation. Using a combination of whole-genome and transcriptome sequencing, we characterized sequence evolution and gene expression across the sex chromosomes. We uncovered two distinct evolutionary strata that correspond with known structural rearrangements on the Y chromosome. In the oldest stratum, only a handful of genes remain, and these genes are under strong purifying selection. By comparing sex-linked gene expression with expression of autosomal orthologs in an outgroup, we show that dosage compensation has not evolved in threespine sticklebacks through upregulation of the X chromosome in males. Instead, in the oldest stratum, the genes that still possess a Y chromosome allele are enriched for genes predicted to be dosage sensitive in mammals and yeast. Our results suggest that dosage imbalances may have been avoided at haploinsufficient genes by retaining function of the Y chromosome allele through strong purifying selection. PMID:25818858

  13. Uncovering the evolutionary history of neo-XY sex chromosomes in the grasshopper Ronderosia bergii (Orthoptera, Melanoplinae) through satellite DNA analysis.

    Science.gov (United States)

    Palacios-Gimenez, Octavio M; Milani, Diogo; Lemos, Bernardo; Castillo, Elio R; Martí, Dardo A; Ramos, Erica; Martins, Cesar; Cabral-de-Mello, Diogo C

    2018-01-08

    Neo-sex chromosome systems arose independently multiple times in evolution, presenting the remarkable characteristic of repetitive DNAs accumulation. Among grasshoppers, occurrence of neo-XY was repeatedly noticed in Melanoplinae. Here we analyzed the most abundant tandem repeats of R. bergii (2n = 22, neo-XY♂) using deep Illumina sequencing and graph-based clustering in order to address the neo-sex chromosomes evolution. The analyses revealed ten families of satDNAs comprising about ~1% of the male genome, which occupied mainly C-positive regions of autosomes. Regarding the sex chromosomes, satDNAs were recorded within centromeric or interstitial regions of the neo-X chromosome and four satDNAs occurred in the neo-Y, two of them being exclusive (Rber248 and Rber299). Using a combination of probes we uncovered five well-defined cytological variants for neo-Y, originated by multiple paracentric inversions and satDNA amplification, besides fragmented neo-Y. These neo-Y variants were distinct in frequency between embryos and adult males. The genomic data together with cytogenetic mapping enabled us to better understand the neo-sex chromosome dynamics in grasshoppers, reinforcing differentiation of neo-X and neo-Y and revealing the occurrence of multiple additional rearrangements involved in the neo-Y evolution of R. bergii. We discussed the possible causes that led to differences in frequency for the neo-Y variants between embryos and adults. Finally we hypothesize about the role of DNA satellites in R. bergii as well as putative historical events involved in the evolution of the R. bergii neo-XY.

  14. Dissociable Effects of Sry and Sex Chromosome Complement on Activity, Feeding and Anxiety-Related Behaviours in Mice

    OpenAIRE

    Kopsida, Eleni; Lynn, Phoebe M.; Humby, Trevor; Wilkinson, Lawrence S.; Davies, William

    2013-01-01

    Hide Figures\\ud Abstract\\ud Introduction\\ud Materials and Methods\\ud Results\\ud Discussion\\ud Supporting Information\\ud Acknowledgments\\ud Author Contributions\\ud References\\ud Reader Comments (0)\\ud Figures\\ud Abstract\\ud \\ud Whilst gonadal hormones can substantially influence sexual differentiation of the brain, recent findings have suggested that sex-linked genes may also directly influence neurodevelopment. Here we used the well-established murine ‘four core genotype’ (FCG) model on a gon...

  15. Mitotic chromosome structure

    International Nuclear Information System (INIS)

    Heermann, Dieter W.

    2012-01-01

    Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

  16. Mitotic chromosome structure

    Energy Technology Data Exchange (ETDEWEB)

    Heermann, Dieter W., E-mail: heermann@tphys.uni-heidelberg.de

    2012-07-15

    Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

  17. Abnormal sex chromosome constitution and longitudinal growth: serum levels of insulin-like growth factor (IGF)-I, IGF binding protein-3, luteinizing hormone, and testosterone in 109 males with 47,XXY, 47,XYY, or sex-determining region of the Y chromosome (SRY)-positive 46,XX karyotypes

    DEFF Research Database (Denmark)

    Aksglaede, L.; Skakkebaek, N.E.; Juul, A.

    2008-01-01

    CONTEXT: Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles. AIM: The aim of the study was to evaluate the role of abnormal chromosome constitution for longitu......CONTEXT: Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles. AIM: The aim of the study was to evaluate the role of abnormal chromosome constitution...... and sitting height, serum levels of reproductive hormones, IGF-I, and IGFBP-3 were measured. RESULTS: In boys with 47,XXY and 47,XYY karyotypes, growth was accelerated already in childhood, compared with healthy boys. 46,XX-males were significantly shorter than healthy boys but matched the stature of healthy...... and elevated LH levels after puberty, whereas the sex hormone secretion of the 47,XYY boys remained normal. CONCLUSION: We found accelerated growth in early childhood in boys with 47,XXY and 47,XYY karyotypes, whereas 46,XX-males were shorter than controls. These abnormal growth patterns were not reflected...

  18. RAD21L, a novel cohesin subunit implicated in linking homologous chromosomes in mammalian meiosis.

    Science.gov (United States)

    Lee, Jibak; Hirano, Tatsuya

    2011-01-24

    Cohesins are multi-subunit protein complexes that regulate sister chromatid cohesion during mitosis and meiosis. Here we identified a novel kleisin subunit of cohesins, RAD21L, which is conserved among vertebrates. In mice, RAD21L is expressed exclusively in early meiosis: it apparently replaces RAD21 in premeiotic S phase, becomes detectable on the axial elements in leptotene, and stays on the axial/lateral elements until mid pachytene. RAD21L then disappears, and is replaced with RAD21. This behavior of RAD21L is unique and distinct from that of REC8, another meiosis-specific kleisin subunit. Remarkably, the disappearance of RAD21L at mid pachytene correlates with the completion of DNA double-strand break repair and the formation of crossovers as judged by colabeling with molecular markers, γ-H2AX, MSH4, and MLH1. RAD21L associates with SMC3, STAG3, and either SMC1α or SMC1β. Our results suggest that cohesin complexes containing RAD21L may be involved in synapsis initiation and crossover recombination between homologous chromosomes.

  19. The Genetic Variation of Bali Cattle (Bos javanicus Based on Sex Related Y Chromosome Gene

    Directory of Open Access Journals (Sweden)

    A Winaya

    2011-09-01

    Full Text Available Bali cattle is very popular Indonesian local beef related to their status in community living process of farmers in Indonesia, especially as providers of meat and exotic animal. Bali cattle were able to adapt the limited environment and becoming local livestock that existed until recently.  In our early study by microsatellites showed that Bali cattle have specific allele. In this study we analyzed the variance of partly sex related Y (SRY gene sequence in Bali cattle bull as a source of cement for Artificial Insemination (AI.  Blood from 17 two location of AI center, Singosari, Malang and Baturiti, Bali was collected and then extracted to get the DNA genome.  PCR reaction was done to amplify partially of SRY gene segment and followed by sequencing PCR products to get the DNA sequence of SRY gene. The SRY gene sequence was used to determine the genetic variation and phylogenetic relationship.  We found that Bali cattle bull from Singosari has relatively closed genetic relationship with Baturiti. It is also supported that in early data some Bali bulls of Singosari were came from Baturiti. It has been known that Baturiti is the one source of Bali cattle bull with promising genetic potential. While, in general that Bali bull where came from two areas were not different on reproductive performances. It is important to understand about the genetic variation of Bali cattle in molecular level related to conservation effort and maintaining the genetic characters of the local cattle. So, it will not become extinct or even decreased the genetic quality of Indonesian indigenous cattle.   Key Words : Bali cattle, SRY gene, artificial insemination, phylogenetic, allele   Animal Production 13(3:150-155 (2011

  20. Fissions, fusions, and translocations shaped the karyotype and multiple sex chromosome constitution of the northeast-Asian wood white butterfly, Leptidea amurensis

    Czech Academy of Sciences Publication Activity Database

    Šíchová, Jindra; Ohno, M.; Dincă, V.; Watanabe, M.; Sahara, K.; Marec, František

    2016-01-01

    Roč. 118, č. 3 (2016), s. 457-471 ISSN 0024-4066 R&D Projects: GA ČR(CZ) GA14-22765S Grant - others:GA JU(CZ) 052/2013/P Institutional support: RVO:60077344 Keywords : karyotype evolution * meiotic pairing * multiple sex chromosomes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.288, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/bij.12756/full

  1. Attention-deficit hyperactivity disorder symptoms in children and adolescents with sex chromosome aneuploidy: XXY, XXX, XYY, and XXYY.

    Science.gov (United States)

    Tartaglia, Nicole R; Ayari, Natalie; Hutaff-Lee, Christa; Boada, Richard

    2012-05-01

    Attentional problems, hyperactivity, and impulsivity have been described as behavioral features associated with sex chromosome aneuploidy (SCA). In this study, the authors compare attention-deficit hyperactivity disorder (ADHD) symptoms in 167 participants aged 6 to 20 years with 4 types of SCA (XXY n = 56, XYY n = 33, XXX n = 25, and XXYY n = 53). They also evaluate factors associated with ADHD symptomatology (cognitive and adaptive scores, prenatal vs postnatal ascertainment) and describe the clinical response to psychopharmacologic medications in a subset of patients treated for ADHD. Evaluation included medical and developmental history, cognitive and adaptive functioning assessment, and parent and teacher ADHD questionnaires containing DSM-IV criteria. In the total study group, 58% (96/167) met DSM-IV criteria for ADHD on parent-report questionnaires (36% in XXY, 52% in XXX, 76% in XYY, and 72% in XXYY). The Inattentive subtype was most common in XXY and XXX, whereas the XYY and XXYY groups were more likely to also have hyperactive/impulsive symptoms. There were no significant differences in Verbal, Performance, or Full Scale IQ between children with symptom scores in the ADHD range compared with those below the ADHD range. However, adaptive functioning scores were significantly lower in the group whose scores in the ADHD range were compared with those of the group who did not meet ADHD DSM-IV criteria. Those with a prenatal diagnosis of XXY were less likely to meet criteria for ADHD compared with the postnatally diagnosed group. Psychopharmacologic treatment with stimulants was effective in 78.6% (66/84). Children and adolescents with SCA are at increased risk for ADHD symptoms. Recommendations for ADHD evaluation and treatment in consideration of other aspects of the SCA medical and behavioral phenotype are provided.

  2. “How should I tell my child?” Disclosing the Diagnosis of Sex Chromosome Aneuploidies

    Science.gov (United States)

    Dennis, Anna; Howell, Susan; Cordeiro, Lisa; Tartaglia, Nicole

    2017-01-01

    To date, the disclosure of a sex chromosome aneuploidy (SCA) diagnosis to an affected individual has not been explored. This study aimed to assess the timing and content revealed to an affected child by his or her parent(s), resources accessed in preparation, parental feelings of preparedness, common parental concerns, and recommendations for disclosure approaches. Two online surveys were created: 1) for parents of a child with a diagnosis and 2) for individuals with a diagnosis. One-hundred thirty-nine parent surveys (XXY n=68, XXX n=21, XYY n=9, other SCAs n=41) and 67 individual surveys (XXY n=58, XXX n=9) were analyzed. Parents most frequently discussed the topics of learning disabilities (47%) and genetics (45%) with their child during the initial disclosure. A significantly greater proportion of parent respondents reported feeling prepared vs. unprepared for disclosure, regardless of their child’s diagnosis (z-test of proportions, all p’sparents most frequently accessed resources such as websites, support groups, and discussion with the child’s physician prior to disclosure, with unprepared parents accessing fewer resources (M = 2.0 ± 1.41) than prepared parents [M= 2. ± 1.56; t(101) = −2.02, pparental concerns included making the conversation age-appropriate, discussing infertility, and possible impact on the child’s self-esteem. Both parent and individual respondents endorsed being honest with the child, disclosing the diagnosis early and before puberty, and discussing the diagnosis gradually over time. These results provide recommendations for parents, and suggest benefits from additional resources and supports to alleviate concerns when approaching diagnosis disclosure. PMID:25179748

  3. Knockdown of αII spectrin in normal human cells by siRNA leads to chromosomal instability and decreased DNA interstrand cross-link repair

    International Nuclear Information System (INIS)

    McMahon, Laura W.; Zhang Pan; Sridharan, Deepa M.; Lefferts, Joel A.; Lambert, Muriel W.

    2009-01-01

    Nonerythroid α-spectrin (αIISp) is a structural protein involved in repair of DNA interstrand cross-links and is deficient in cells from patients with Fanconi anemia (FA), which are defective in ability to repair cross-links. In order to further demonstrate the importance of the role that αIISp plays in normal human cells and in the repair defect in FA, αIISp was knocked down in normal cells using siRNA. Depletion of αIISp in normal cells by siRNA resulted in chromosomal instability and cellular hypersensitivity to DNA interstrand cross-linking agents. An increased number of chromosomal aberrations were observed and, following treatment with a DNA interstrand cross-linking agent, mitomycin C, cells showed decreased cell growth and survival and decreased formation of damage-induced αIISp and XPF nuclear foci. Thus depletion of αIISp in normal cells leads to a number of defects observed in FA cells, such as chromosome instability and a deficiency in cross-link repair.

  4. A specific insertion of a solo-LTR characterizes the Y-chromosome of Bryonia dioica (Cucurbitaceae).

    Science.gov (United States)

    Oyama, Ryan K; Silber, Martina V; Renner, Susanne S

    2010-06-14

    Relatively few species of flowering plants are dioecious and even fewer are known to have sex chromosomes. Current theory posits that homomorphic sex chromosomes, such as found in Bryonia dioica (Cucurbitaceae), offer insight into the early stages in the evolution of sex chromosomes from autosomes. Little is known about these early steps, but an accumulation of transposable element sequences has been observed on the Y-chromosomes of some species with heteromorphic sex chromosomes. Recombination, by which transposable elements are removed, is suppressed on at least part of the emerging Y-chromosome, and this may explain the correlation between the emergence of sex chromosomes and transposable element enrichment. We sequenced 2321 bp of the Y-chromosome in Bryonia dioica that flank a male-linked marker, BdY1, reported previously. Within this region, which should be suppressed for recombination, we observed a solo-LTR nested in a Copia-like transposable element. We also found other, presumably paralogous, solo-LTRs in a consensus sequence of the underlying Copia-like transposable element. Given that solo-LTRs arise via recombination events, it is noteworthy that we find one in a genomic region where recombination should be suppressed. Although the solo-LTR could have arisen before recombination was suppressed, creating the male-linked marker BdY1, our previous study on B. dioica suggested that BdY1 may not lie in the recombination-suppressed region of the Y-chromosome in all populations. Presence of a solo-LTR near BdY1 therefore fits with the observed correlation between retrotransposon accumulation and the suppression of recombination early in the evolution of sex chromosomes. These findings further suggest that the homomorphic sex chromosomes of B. dioica, the first organism for which genetic XY sex-determination was inferred, are evolutionarily young and offer reference information for comparative studies of other plant sex chromosomes.

  5. Haldane’s Rule Is Linked to Extraordinary Sex Ratios and Sperm Length in Stalk-Eyed Flies

    Science.gov (United States)

    Wilkinson, Gerald S.; Christianson, Sarah J.; Brand, Cara L.; Ru, George; Shell, Wyatt

    2014-01-01

    We use three allopatric populations of the stalk-eyed fly Teleopsis dalmanni from Southeast Asia to test two predictions made by the sex chromosome drive hypothesis for Haldane’s rule. The first is that modifiers that suppress or enhance drive should evolve rapidly and independently in isolated populations. The second is that drive loci or modifiers should also cause sterility in hybrid males. We tested these predictions by assaying the fertility of 2066 males derived from backcross experiments involving two pairs of populations and found that the proportion of mated males that fail to produce any offspring ranged from 38 to 60% among crosses with some males producing strongly female-biased or male-biased sex ratios. After genotyping each male at 25–28 genetic markers we found quantitative trait loci (QTL) that jointly influence male sterility, sperm length, and biased progeny sex ratios in each pair of populations, but almost no shared QTL between population crosses. We also discovered that the extant XSR chromosome has no effect on sex ratio or sterility in these backcross males. Whether shared QTL are caused by linkage or pleiotropy requires additional study. Nevertheless, these results indicate the presence of a “cryptic” drive system that is currently masked by suppressing elements that are associated with sterility and sperm length within but not between populations and, therefore, must have evolved since the populations became isolated, i.e., in hybrid sterility. PMID:25164880

  6. Quantitative variation in obesity-related traits and insulin precursors linked to the OB gene region on human chromosome 7

    Energy Technology Data Exchange (ETDEWEB)

    Duggirala, R.; Stern, M.P.; Reinhart, L.J. [Univ. of Texas Health Science Center, San Antonio, TX (United States)] [and others

    1996-09-01

    Despite the evidence that human obesity has strong genetic determinants, efforts at identifying specific genes that influence human obesity have largely been unsuccessful. Using the sibship data obtained from 32 low-income Mexican American pedigrees ascertained on a type II diabetic proband and a multipoint variance-components method, we tested for linkage between various obesity-related traits plus associated metabolic traits and 15 markers on human chromosome 7. We found evidence for linkage between markers in the OB gene region and various traits, as follows: D7S514 and extremity skinfolds (LOD = 3.1), human carboxypeptidase A1 (HCPA1) and 32,33-split proinsulin level (LOD = 4.2), and HCPA1 and proinsulin level (LOD = 3.2). A putative susceptibility locus linked to the marker D7S514 explained 56% of the total phenotypic variation in extremity skinfolds. Variation at the HCPA1 locus explained 64% of phenotypic variation in proinsulin level and {approximately}73% of phenotypic variation in split proinsulin concentration, respectively. Weaker evidence for linkage to several other obesity-related traits (e.g., waist circumference, body-mass index, fat mass by bioimpedance, etc.) was observed for a genetic location, which is {approximately}15 cM telomeric to OB. In conclusion, our study reveals that the OB region plays a significant role in determining the phenotypic variation of both insulin precursors and obesity-related traits, at least in Mexican Americans. 66 refs., 3 figs., 4 tabs.

  7. The genetics of dementias. Part 1: Molecular basis of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17

    Directory of Open Access Journals (Sweden)

    Anna Kowalska

    2009-06-01

    Full Text Available Frontotemporal dementia (FTD, characterized by neurodegeneration mainly in the frontal and temporal lobes, accounts for ca. 10–15�0of all dementias. In 1892 the Czech-German neuropsychiatrist Arnold Pick reported the first case of FTD in a 71-year-old patient suffering from progressive dementia, memory disturbances, and aphasia associated with frontal and temporal lobe atrophy and the presence of neuronal inclusions. Later the inclusions were named Pick bodies. The neuropathological hallmark of FTD is very differentiated. In contrast to Alzheimer’s disease (AD, there are neither senile plaques nor neurofibrillary tangles in the brains of FTD patients. Frontotemporal dementias are tauopathies, a group of disorders caused by aberrant metabolism of tau protein, a family of proteins associated with microtubules (MAPT: macrotubule-associated tau protein. In the nervous system the protein stabilizes microtubules in neuronal axons and is thus responsible for crucial processes in neuron metabolism, such as signal transduction, plasticity, and intracellular transport. In the human brain, six isoforms are produced from the MAPT gene (chromosome 17 q21.2 by alternative mRNA splicing. The isoforms differ in the number of amino acids in the protein chain, the presence of three (3R tau type or four (4R tau type domains responsible for binding to microtubules, and one or two inserts containing from 29 to 58 amino acids. The isoforms are modified posttranslationally by hyperphosphorylation, glycation, or oxidation, which can change the protein’s properties and disturb its normal function. Altered metabolism of tau protein changes its interactions with tubulin, leading to destabilization of the microtubule structure and initiating the generation of toxic tau aggregates. The first mutations in the MAPT gene responsible for frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17 were found in 1998. So far over 40 mutations in the MAPT

  8. Borealin/Dasra B is a cell cycle-regulated chromosomal passenger protein and its nuclear accumulation is linked to poor prognosis for human gastric cancer

    International Nuclear Information System (INIS)

    Chang, J.-L.; Chen, T.-H.; Wang, C.-F.; Chiang, Y.-H.; Huang, Y.-L.; Wong, F.-H.; Chou, C.-K.; Chen, C.-M.

    2006-01-01

    Chromosomal passenger proteins including Aurora B, Survivin, and Borealin/Dasra B, also called CDCA8/FLJ10468, are known to play crucial roles during mitosis and cell division. Inappropriate chromosomal segregation and cell division may cause auneuploidy leading to cancer. However, it is still unclear how the expression of chromosomal passenger proteins may be linked to cancer. In this study, we demonstrated that Borealin is a cell cycle-regulated gene and is upregulated at G2-M phases of the cell cycle. We showed that Borealin interacts with Survivin but not with Aurora B. The interaction domain of Survivin in Borealin was mapped to the N-terminal 92 amino-acid residues of Borealin. To examine the linkage between expression of Borealin and cancer, we performed immunohistochemistry analysis using anti-Borealin specific antibody on the paraffin-embedded gastric cancer tissues. Our results showed that Borealin expression is significantly correlated with Survivin (P = 0.003) and Ki67 (P = 0.007) in gastric cancer. Interestingly, an increased nuclear Borealin level reveals borderline association with a poor survival rate (P = 0.047). Taken together, our results demonstrated that Borealin is a cell cycle-regulated chromosomal passenger protein and its aberrant expression is linked to a poor prognosis for gastric cancer

  9. Effects of thyroid hormones on cartilage sulphation in sex-linked dwarf chickens

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, S.; Wakita, M.; Kobayashi, Y. (Faculty of Bioresources, Mie University, Tsu (Japan)); Kakegawa, T.; Suzuki, M. (Institute of Endocrinology, Gunma University, Maebashi (Japan))

    1989-01-01

    The present investigation was undertaken to see if exogenous thyroid hormone could stimulate cartilage sulphation in vivo and in vitro in sex-linked dwarf chickens. L-thyroxine or L-3,5,3'-triiodothyronine injection for 7 consecutive days stimulated in vivo /sup 35/SO/sub 4//sup 2-/ incorporation into trachea cartilages of the dwarf chicken. Both thyroid hormones added to the incubation medium with or without 2,5% dwarf chicken serum also stimulated in vitro /sup 35/SO/sub 4//sup 2-/ incorporation into pelvic rudiment from 11-day chick embryos. These data demonstrate that thyroid hormones, like insulin-like growth factor I, might be responsible for the reduced growth rate of dwarf chickens. (author).

  10. Y Chromosome DNA in Women's Vaginal Samples as a Biomarker of Recent Vaginal Sex and Condom Use With Male Partners in the HPV Infection and Transmission Among Couples Through Heterosexual Activity Cohort Study.

    Science.gov (United States)

    Malagón, Talía; Burchell, Ann; El-Zein, Mariam; Guénoun, Julie; Tellier, Pierre-Paul; Coutlée, François; Franco, Eduardo L

    2018-01-01

    Y chromosome DNA from male epithelial and sperm cells was detected in vaginal samples after unprotected sex in experimental studies. We assessed the strength of this association in an observational setting to examine the utility of Y chromosome DNA as a biomarker of recent sexual behaviors in epidemiological studies. The HPV (human papillomavirus) Infection and Transmission Among Couples Through Heterosexual Activity cohort study enrolled 502 women attending a university or college in Montréal, Canada, and their male partners from 2005 to 2010. Participants completed self-administered questionnaires. We used real-time polymerase chain reaction to test women's baseline vaginal samples for Y chromosome DNA and assessed which sexual behaviors were independent predictors of Y chromosome DNA positivity and quantity with logistic and negative binomial regression. Y chromosome DNA positivity decreased from 77% in women in partnerships reporting vaginal sex 0 to 1 day ago to 13% in women in partnerships reporting last vaginal sex of 15 or more days ago (adjusted odds ratio, 0.09; 95% confidence interval, 0.02-0.36). The mean proportion of exfoliated vaginal sample cells with Y chromosome DNA was much lower for women who reported always using condoms (0.01%) than for women who reported never using condoms (2.07%) (adjusted ratio, 26.8; 95% confidence interval, 8.9-80.5). No association was found with reported oral/digital sex frequency or concurrency of partnerships. Y chromosome DNA quantity is strongly associated with days since last vaginal sex and lack of condom use in observational settings. Y chromosome DNA quantity may prove useful as a correlate of recent vaginal sex in observational studies lacking data on sexual behavior, such as surveillance studies of human papillomavirus infection prevalence.

  11. Sex-Linked Mating Strategies Diverge with a Manipulation of Genital Salience.

    Science.gov (United States)

    Fetterman, Adam K; Kruger, Nicole N; Robinson, Michael D

    2015-02-01

    Trivers (1972) proposed that evolutionary factors should favor divergent mating strategies for males versus females. Such differences may be less pronounced among human beings than other animals and social norms and sex roles are also pertinent influences. The present experiment ( N = 133 college undergraduates, 74 female) sought to bypass some of these other influences. Participants were randomly assigned to a condition designed to increase attention to the genital region (a downward pointing arrow) or not (an upward pointing arrow). They then reported on their interest in short-term (e.g., a one-night stand) and long-term (e.g., a potential marital partner) mating opportunities. A theory-consistent three-way interaction occurred such that the genital salience manipulation primed a shorter-term reproductive strategy among men and a longer-term reproductive strategy among women. The results provide unique support for evolution-linked ideas about sex differences in the form of a role for bodily attention.

  12. Identification of a sex-linked SNP marker in the salmon louse (Lepeophtheirus salmonis using RAD sequencing.

    Directory of Open Access Journals (Sweden)

    Stephen N Carmichael

    Full Text Available The salmon louse (Lepeophtheirus salmonis (Krøyer, 1837 is a parasitic copepod that can, if untreated, cause considerable damage to Atlantic salmon (Salmo salar Linnaeus, 1758 and incurs significant costs to the Atlantic salmon mariculture industry. Salmon lice are gonochoristic and normally show sex ratios close to 1:1. While this observation suggests that sex determination in salmon lice is genetic, with only minor environmental influences, the mechanism of sex determination in the salmon louse is unknown. This paper describes the identification of a sex-linked Single Nucleotide Polymorphism (SNP marker, providing the first evidence for a genetic mechanism of sex determination in the salmon louse. Restriction site-associated DNA sequencing (RAD-seq was used to isolate SNP markers in a laboratory-maintained salmon louse strain. A total of 85 million raw Illumina 100 base paired-end reads produced 281,838 unique RAD-tags across 24 unrelated individuals. RAD marker Lsa101901 showed complete association with phenotypic sex for all individuals analysed, being heterozygous in females and homozygous in males. Using an allele-specific PCR assay for genotyping, this SNP association pattern was further confirmed for three unrelated salmon louse strains, displaying complete association with phenotypic sex in a total of 96 genotyped individuals. The marker Lsa101901 was located in the coding region of the prohibitin-2 gene, which showed a sex-dependent differential expression, with mRNA levels determined by RT-qPCR about 1.8-fold higher in adult female than adult male salmon lice. This study's observations of a novel sex-linked SNP marker are consistent with sex determination in the salmon louse being genetic and following a female heterozygous system. Marker Lsa101901 provides a tool to determine the genetic sex of salmon lice, and could be useful in the development of control strategies.

  13. One and a half million medical papers reveal a link between author gender and attention to gender and sex analysis

    DEFF Research Database (Denmark)

    Nielsen, Mathias Wullum; Andersen, Jens Peter; Schiebinger, Londa

    2017-01-01

    Gender and sex analysis is increasingly recognized as a key factor in creating better medical research and health care. Using a sample of more than 1.5 million medical research papers, our study examined the potential link between women’s participation in medical science and attention to gender......-related and sex-related factors in disease-specific research. Adjusting for variations across countries, disease topics and medical research areas, we compared the participation of women authors in studies that do and do not involve gender and sex analysis. Overall, our results show a robust positive correlation...... between women’s authorship and the likelihood of a study including gender and sex analysis. These findings corroborate discussions of how women’s participation in medical science links to research outcomes, and show the mutual benefits of promoting both the scientific advancement of women...

  14. Knockdown of αII spectrin in normal human cells by siRNA leads to chromosomal instability and decreased DNA interstrand cross-link repair

    OpenAIRE

    McMahon, Laura W.; Zhang, Pan; Sridharan, Deepa M.; Lefferts, Joel A.; Lambert, Muriel W.

    2009-01-01

    Nonerythroid α-spectrin (αIISp) is a structural protein involved in repair of DNA interstrand cross-links and is deficient in cells from patients with Fanconi anemia (FA), which are defective in ability to repair cross-links. In order to further demonstrate the importance of the role that αIISp plays in normal human cells and in the repair defect in FA, αIISp was knocked down in normal cells using siRNA. Depletion of αIISp in normal cells by siRNA resulted in chromosomal instability and cellu...

  15. A dense SNP-based linkage map for Atlantic salmon (Salmo salar reveals extended chromosome homeologies and striking differences in sex-specific recombination patterns

    Directory of Open Access Journals (Sweden)

    Lien Sigbjørn

    2011-12-01

    Full Text Available Abstract Background The Atlantic salmon genome is in the process of returning to a diploid state after undergoing a whole genome duplication (WGD event between 25 and100 million years ago. Existing data on the proportion of paralogous sequence variants (PSVs, multisite variants (MSVs and other types of complex sequence variation suggest that the rediplodization phase is far from over. The aims of this study were to construct a high density linkage map for Atlantic salmon, to characterize the extent of rediploidization and to improve our understanding of genetic differences between sexes in this species. Results A linkage map for Atlantic salmon comprising 29 chromosomes and 5650 single nucleotide polymorphisms (SNPs was constructed using genotyping data from 3297 fish belonging to 143 families. Of these, 2696 SNPs were generated from ESTs or other gene associated sequences. Homeologous chromosomal regions were identified through the mapping of duplicated SNPs and through the investigation of syntenic relationships between Atlantic salmon and the reference genome sequence of the threespine stickleback (Gasterosteus aculeatus. The sex-specific linkage maps spanned a total of 2402.3 cM in females and 1746.2 cM in males, highlighting a difference in sex specific recombination rate (1.38:1 which is much lower than previously reported in Atlantic salmon. The sexes, however, displayed striking differences in the distribution of recombination sites within linkage groups, with males showing recombination strongly localized to telomeres. Conclusion The map presented here represents a valuable resource for addressing important questions of interest to evolution (the process of re-diploidization, aquaculture and salmonid life history biology and not least as a resource to aid the assembly of the forthcoming Atlantic salmon reference genome sequence.

  16. Defective balancing ability and hyperactivity in the CLX (circling behavior linked to the X-chromosome) mutant rat.

    Science.gov (United States)

    Fuji, Jun-ichiro; Tanabe, Hiroyuki; Fukuda, Ryo; Ooshima, Yojiro

    2003-12-01

    We have reported that the recently described circling behavior rat (CLX) is a hereditary mutant controlled by a single sex-linked recessive gene (gene symbol: clx). This mutant shows intermittent circle walking and/or running and head tossing with the neck twisted. The abnormal behavior begins to appear around weaning and continues throughout life. In the present study, behavioral tests were performed during the suckling and post-weaning periods and when the rats reached maturity, and the following peculiar abnormalities were revealed: (1) in the righting reflex test, the CLX young show a tendency to take a longer time to revert to normal posture; (2) in the negative geotaxis test, they had difficulty moving upward at 12 days of age; (3) in the air righting reflex test, they frequently fell on their backs or shoulders even after weaning; (4) almost none of the CLX rats showed nystagmus, which is invariably observed in normal rats after rotating stimulation, at 20 weeks of age; and (5) they showed hyperactivity in the open field test at the age of 5 or 6 weeks and a higher degree of locomotor activity in the home cage at the age of 7 and 15 weeks. These results suggest that CLX mutant rats may have some defect in vestibular function (balance sense) or abnormalities in an area of the central nervous system responsible for posture control, e.g., in the dopaminergic or GABAergic neurons.

  17. Molecular Method for Sex Identification of Half-Smooth Tongue Sole (Cynoglossus semilaevis Using a Novel Sex-Linked Microsatellite Marker

    Directory of Open Access Journals (Sweden)

    Xiaolin Liao

    2014-07-01

    Full Text Available Half-smooth tongue sole (Cynoglossus semilaevis is one of the most important flatfish species for aquaculture in China. To produce a monosex population, we attempted to develop a marker-assisted sex control technique in this sexually size dimorphic fish. In this study, we identified a co-dominant sex-linked marker (i.e., CyseSLM by screening genomic microsatellites and further developed a novel molecular method for sex identification in the tongue sole. CyseSLM has a sequence similarity of 73%–75% with stickleback, medaka, Fugu and Tetraodon. At this locus, two alleles (i.e., A244 and A234 were amplified from 119 tongue sole individuals with primer pairs CyseSLM-F1 and CyseSLM-R. Allele A244 was present in all individuals, while allele A234 (female-associated allele, FAA was mostly present in females with exceptions in four male individuals. Compared with the sequence of A244, A234 has a 10-bp deletion and 28 SNPs. A specific primer (CyseSLM-F2 was then designed based on the A234 sequence, which amplified a 204 bp fragment in all females and four males with primer CyseSLM-R. A time-efficient multiplex PCR program was developed using primers CyseSLM-F2, CyseSLM-R and the newly designed primer CyseSLM-F3. The multiplex PCR products with co-dominant pattern could be detected by agarose gel electrophoresis, which accurately identified the genetic sex of the tongue sole. Therefore, we have developed a rapid and reliable method for sex identification in tongue sole with a newly identified sex-linked microsatellite marker.

  18. +2.71 LOD score at zero recombination is not sufficient for establishing linkage between X-linked mental retardation and X-chromosome markers

    Energy Technology Data Exchange (ETDEWEB)

    Robledo, R.; Melis, P.; Siniscalco, M. [and others

    1996-07-12

    Nonspecific X-linked mental retardation (MRX) is the denomination attributed to the familial type of mental retardation compatible with X-linked inheritance but lacking specific phenotypic manifestations. It is thus to be expected that families falling under such broad definition are genetically heterogeneous in the sense that they may be due to different types of mutations occurring, most probably, at distinct X-chromosome loci. To facilitate a genetic classification of these conditions, the Nomenclature Committee of the Eleventh Human Gene Mapping Workshop proposed to assign a unique MRX-serial number to each family where evidence of linkage with one or more X-chromosome markers had been established with a LOD score of at least +2 at zero recombination. This letter is meant to emphasize the inadequacy of this criterion for a large pedigree where the segregation of the disease has been evaluated against the haplotype constitution of the entire X-chromosome carrying the mutation in question. 12 refs., 2 figs., 1 tab.

  19. Status Hierarchy, Attractiveness Hierarchy and Sex Ratio: Three Contextual Factors Explaining the Status-Aggression Link among Adolescents

    Science.gov (United States)

    Zwaan, Michiel; Dijkstra, Jan Kornelis; Veenstra, Rene

    2013-01-01

    The moderating effects of three specific conditions (status hierarchy, attractiveness hierarchy and sex ratio) on the link between status (popularity) and physical and relational aggression were examined in a large sample of adolescent boys ("N" = 1,665) and girls ("N" = 1,637) ("M" age = 13.60). In line with the…

  20. Status hierarchy, attractiveness hierarchy and sex ratio : Three contextual factors explaining the status-aggression link among adolescents

    NARCIS (Netherlands)

    Zwaan, Michiel; Dijkstra, Jan; Veenstra, René

    The moderating effects of three specific conditions (status hierarchy, attractiveness hierarchy and sex ratio) on the link between status (popularity) and physical and relational aggression were examined in a large sample of adolescent boys (N = 1,665) and girls (N = 1,637) (M age = 13.60). In line

  1. YY1 binding association with sex-biased transcription revealed through X-linked transcript levels and allelic binding analyses.

    Science.gov (United States)

    Chen, Chih-Yu; Shi, Wenqiang; Balaton, Bradley P; Matthews, Allison M; Li, Yifeng; Arenillas, David J; Mathelier, Anthony; Itoh, Masayoshi; Kawaji, Hideya; Lassmann, Timo; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R R; Brown, Carolyn J; Wasserman, Wyeth W

    2016-11-18

    Sex differences in susceptibility and progression have been reported in numerous diseases. Female cells have two copies of the X chromosome with X-chromosome inactivation imparting mono-allelic gene silencing for dosage compensation. However, a subset of genes, named escapees, escape silencing and are transcribed bi-allelically resulting in sexual dimorphism. Here we conducted in silico analyses of the sexes using human datasets to gain perspectives into such regulation. We identified transcription start sites of escapees (escTSSs) based on higher transcription levels in female cells using FANTOM5 CAGE data. Significant over-representations of YY1 transcription factor binding motif and ChIP-seq peaks around escTSSs highlighted its positive association with escapees. Furthermore, YY1 occupancy is significantly biased towards the inactive X (Xi) at long non-coding RNA loci that are frequent contacts of Xi-specific superloops. Our study suggests a role for YY1 in transcriptional activity on Xi in general through sequence-specific binding, and its involvement at superloop anchors.

  2. Diminished hepatic growth hormone receptor binding in sex-linked dwarf broiler and leghorn chickens.

    Science.gov (United States)

    Leung, F C; Styles, W J; Rosenblum, C I; Lilburn, M S; Marsh, J A

    1987-02-01

    Hepatic growth hormone (GH) receptor binding was compared in normal and sex-linked dwarfs (SLD) from both Hubbard and Cornell strain chickens. At 6, 8, and 20 weeks of age, hepatic GH receptor binding in the Hubbard SLD chickens was significantly lower than that of normal fast-growing birds. At 20 weeks of age, only 2 of 22 SLD chickens in the Hubbard broiler strain showed positive binding at a high enough level to allow for Scatchard analysis. The affinity constants and binding capacities of these two SLD chickens were numerically (but not significantly) lower than those of the normal fast-growing birds. We further examined hepatic GH receptor binding in two closely related White Leghorn strains of chickens that have been maintained as closed breeding populations for many years. We observed no detectable hepatic GH binding in the Cornell SLD chickens (N = 20), as compared to the normal-growing control strain (K strain). In both SLD strains, pretreatment with 4 M MgCl2 did not enhance GH binding, suggesting that there was no endogenous GH binding to the receptor. Based on these data, we suggest that the lack, or greatly reduced number, of GH receptors may be a major contributing factor to the dwarfism observed in these strains.

  3. Comparative study of different sexis mutability: recessive sex-linked and dominant lethals in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Vatti, K.V.; Dzhaparidze, L.A.; Mamon, L.A.

    1980-01-01

    The frequency of recessive sex-linked lethal mutations (RSLLM) and those realizing in embryogenesis of dominant lethals, which form in oo- and spermatogenesis of Drosophila and fly productivity under the effect of X-rays and N-nitroso-N methylourea (NMU), is studied. In the case of effect of both mutagens RSLLM form in spermatocytes with higher frequency as compared with oocytes. Dominant lethal mutations (DLM) during irradiation are also often registered in spermatocytes. NMU induces DLM in mitotic male cells with a very high frequency but is not effective during the effect on oocytes. When both mutagens affect males and X-rays affect females, the decrease of productivity is mainly conditioned by DLM. As NMU does not induce DLM in females realizing in embryogenesis but reduces productivity, a later lethal realization connected with their different nature is supposed. Differences in mole and female mutability found in the course of X-ray and NMU effect are discussed in connection with peculiarities of their mitotic cells and the nature of effect of mutagens applied [ru

  4. Vitamin D deficiency and low ionized calcium are linked with semen quality and sex steroid levels in infertile men

    DEFF Research Database (Denmark)

    Jensen, Martin Blomberg; Lawaetz, Jacob Gerner; Andersson, Anna-Maria

    2016-01-01

    STUDY QUESTION: Are low vitamin D levels linked with semen quality and sex steroids in infertile men? SUMMARY ANSWER: Infertile men with vitamin D deficiency had lower sperm motility, total numbers of motile sperm, Inhibin B, sex-hormone-binding-globulin (SHBG) and testosterone/estradiol ratio......, but higher levels of free sex steroids, than infertile men with normal vitamin D levels. WHAT IS KNOWN ALREADY: Low vitamin D levels have been associated with decreased sperm motility in healthy men, but a relationship between vitamin D and calcium with semen quality and especially sex steroids has not been...... infertile men, consecutively referred to our tertiary andrological centre for fertility workup, underwent a physical examination and had semen quality assessed based on two samples and blood analysed for serum testosterone, SHBG, estradiol, inhibin B, luteinizing hormone, follicle-stimulating hormone (FSH...

  5. Uptake of a women-only, sex-work-specific drop-in center and links with sexual and reproductive health care for sex workers.

    Science.gov (United States)

    Kim, Soyoun Rachel; Goldenberg, Shira M; Duff, Putu; Nguyen, Paul; Gibson, Kate; Shannon, Kate

    2015-03-01

    To longitudinally examine female sex workers' (FSWs') uptake of a women-only, sex-work-specific drop-in service and its impact on their access to sexual and reproductive health (SRH) services. For the present longitudinal analysis, data were drawn from the AESHA (An Evaluation of Sex Workers' Health Access) study, a community-based, open, prospective cohort of FSWs from Vancouver, BC, Canada. Data obtained between January 2010 and February 2013 were analyzed. Participants are followed up on a semi-annual basis. Multivariable logistic regression using generalized estimating equations was used to identify correlates of service uptake. Of 547 FSWs included in the present analysis, 330 (60.3%) utilized the services during the 3-year study period. Service use was independently associated with age (adjusted odds ratio [AOR] 1.04; 95% confidence interval [CI] 1.03-1.06), Aboriginal ancestry (AOR 2.18; 95% CI 1.61-2.95), injection drug use (AOR 1.67; 95% CI 1.29-2.17), exchange of sex for drugs (AOR 1.40; 95%CI 1.15-1.71), and accessing SRH services (AOR 1.65; 95% CI 1.35-2.02). A sex-work-specific drop-in space for marginalized FSWs had high uptake. Women-centered and low-threshold drop-in services can effectively link marginalized women with SRH services. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  6. A Quantitative Trait Locus (LSq-1) on Mouse Chromosome 7 Is Linked to the Absence of Tissue Loss After Surgical Hindlimb Ischemia

    Science.gov (United States)

    Dokun, Ayotunde O.; Keum, Sehoon; Hazarika, Surovi; Li, Yongjun; Lamonte, Gregory M.; Wheeler, Ferrin; Marchuk, Douglas A.; Annex, Brian H.

    2010-01-01

    Background Peripheral arterial disease (PAD) caused by occlusive atherosclerosis of the lower extremity has 2 major clinical manifestations. Critical limb ischemia is characterized by rest pain and/or tissue loss and has a ≥40% risk of death and major amputation. Intermittent claudication causes pain on walking, has no tissue loss, and has amputation plus mortality rates of 2% to 4% per year. Progression from claudication to limb ischemia is infrequent. Risk factors in most PAD patients overlap. Thus, we hypothesized that genetic variations may be linked to presence or absence of tissue loss in PAD. Methods and Results Hindlimb ischemia (murine model of PAD) was induced in C57BL/6, BALB/c, C57BL/6×BALB/c (F1), F1×BALB/c (N2), A/J, and C57BL/6J-Chr7A/J/NaJ chromosome substitution strains. Mice were monitored for perfusion recovery and tissue necrosis. Genome-wide scanning with polymorphic markers across the 19 murine autosomes was performed on the N2 mice. Greater tissue loss and poorer perfusion recovery occurred in BALB/c than in the C57BL/6 strain. Analysis of 105 N2 progeny identified a single quantitative trait locus on chromosome 7 that exhibited significant linkage to both tissue necrosis and extent of perfusion recovery. Using the appropriate chromosome substitution strain, we demonstrate that C57BL/6-derived chromosome 7 is required for tissue preservation. Conclusions We have identified a quantitative trait locus on murine chromosome 7 (LSq-1) that is associated with the absence of tissue loss in a preclinical model of PAD and may be useful in identifying gene(s) that influence PAD in humans. PMID:18285563

  7. Deciphering the link between doubly uniparental inheritance of mtDNA and sex determination in bivalves: Clues from comparative transcriptomics

    Science.gov (United States)

    Capt, Charlotte; Renaut, Sébastien; Ghiselli, Fabrizio; Milani, Liliana; Johnson, Nathan A.; Sietman, Bernard E.; Stewart, Donald; Breton, Sophie

    2018-01-01

    Bivalves exhibit an astonishing diversity of sexual systems and sex-determining mechanisms. They can be gonochoric, hermaphroditic or androgenetic, with both genetic and environmental factors known to determine or influence sex. One unique sex-determining system involving the mitochondrial genome has also been hypothesized to exist in bivalves with doubly uniparental inheritance (DUI) of mtDNA. However, the link between DUI and sex determination remains obscure. In this study, we performed a comparative gonad transcriptomics analysis for two DUI-possessing freshwater mussel species to better understand the mechanisms underlying sex determination and DUI in these bivalves. We used a BLAST reciprocal analysis to identify orthologs between Venustaconcha ellipsiformis and Utterbackia peninsularis and compared our results with previously published sex-specific bivalve transcriptomes to identify conserved sex-determining genes. We also compared our data with other DUI species to identify candidate genes possibly involved in the regulation of DUI. A total of ∼12,000 orthologous relationships were found, with 2,583 genes differentially expressed in both species. Among these genes, key sex-determining factors previously reported in vertebrates and in bivalves (e.g., Sry, Dmrt1, Foxl2) were identified, suggesting that some steps of the sex-determination pathway may be deeply conserved in metazoans. Our results also support the hypothesis that a modified ubiquitination mechanism could be responsible for the retention of the paternal mtDNA in male bivalves, and revealed that DNA methylation could also be involved in the regulation of DUI. Globally, our results suggest that sets of genes associated with sex determination and DUI are similar in distantly-related DUI species.

  8. Adaptive sex allocation in birds : The complexities of linking theory and practice

    NARCIS (Netherlands)

    Komdeur, Jan; Pen, Ido

    2002-01-01

    We review some recent theoretical and empirical developments in the study of sex allocation in birds. The advent of reliable molecular sexing techniques has led to a sharp increase in the number of studies that report biased offspring sex ratios in birds. However, compelling evidence for adaptive

  9. An Unusual Accumulation of Ribosomal Multigene Families and Microsatellite DNAs in the XX/XY Sex Chromosome System in the Trans-Andean Catfish Pimelodella cf. chagresi (Siluriformes:Heptapteridae).

    Science.gov (United States)

    Conde-Saldaña, Cristhian Camilo; Barreto, Cynthia Aparecida Valiati; Villa-Navarro, Francisco Antonio; Dergam, Jorge Abdala

    2018-02-01

    This work constitutes the first cytogenetic characterization of a trans-Andean species of Heptapteridae. The catfish Pimelodella cf. chagresi from the Upper Rio Magdalena was studied, applying standard cytogenetic techniques (Giemsa, C-banding, and argyrophilic nucleolar organizer region [Ag-NOR]) and fluorescence in situ hybridization techniques using repetitive DNA probes: microsatellites (CA 15 and GA 15 ) and ribosomal RNA (rRNA) multigene families (18S and 5S recombinant DNA [rDNA] probes). The species showed a unique diploid chromosome number 2n = 50 (32m [metacentrics] +14sm [submetacentrics] +4st [subtelocentrics]) and a XX/XY sex chromosomal system, where the heteromorphic Y-chromosome revealed a conspicuous accumulation of all the assayed domains of repetitive DNA. P. cf. chagresi karyotype shares common features with other Heptapteridae, such as the predominance of metacentric and submetacentric chromosomes, and one pair of subtelomeric nucleolar organizer regions (NORs). These results reflect an independent karyological identity of a trans-Andean species and the relevance of repetitive DNA sequences in the process of sex chromosome differentiation in fish; it is the first case of syntenic accumulation of rRNA multigene families (18S and 5S rDNA) and microsatellite sequences (CA 15 and GA 15 ) in a differentiated sex chromosome in Neotropical fish.

  10. A single nucleotide polymorphism within the novel sex-linked testis-specific retrotransposed PGAM4 gene influences human male fertility.

    Directory of Open Access Journals (Sweden)

    Hidenobu Okuda

    Full Text Available The development of novel fertilization treatments, including in vitro fertilization and intracytoplasmic injection, has made pregnancy possible regardless of the level of activity of the spermatozoa; however, the etiology of male-factor infertility is poorly understood. Multiple studies, primarily through the use of transgenic animals, have contributed to a list of candidate genes that may affect male infertility in humans. We examined single nucleotide polymorphisms (SNPs as a cause of male infertility in an analysis of spermatogenesis-specific genes.We carried out the prevalence of SNPs in the coding region of phosphoglycerate mutase 4 (PGAM4 on the X chromosome by the direct sequencing of PCR-amplified DNA from male patients. Using RT-PCR and western blot analyses, we identified that PGAM4 is a functional retrogene that is expressed predominantly in the testes and is associated with male infertility. PGAM4 is expressed in post-meiotic stages, including spermatids and spermatozoa in the testes, and the principal piece of the flagellum and acrosome in ejaculated spermatozoa. A case-control study revealed that 4.5% of infertile patients carry the G75C polymorphism, which causes an amino acid substitution in the encoded protein. Furthermore, an assay for enzymatic activity demonstrated that this polymorphism decreases the enzyme's activity both in vitro and in vivo.These results suggest that PGAM4, an X-linked retrogene, is a fundamental gene in human male reproduction and may escape meiotic sex chromosome inactivation. These findings provide fresh insight into elucidating the mechanisms of male infertility.

  11. The DNA sequence of the human X chromosome

    Science.gov (United States)

    Ross, Mark T.; Grafham, Darren V.; Coffey, Alison J.; Scherer, Steven; McLay, Kirsten; Muzny, Donna; Platzer, Matthias; Howell, Gareth R.; Burrows, Christine; Bird, Christine P.; Frankish, Adam; Lovell, Frances L.; Howe, Kevin L.; Ashurst, Jennifer L.; Fulton, Robert S.; Sudbrak, Ralf; Wen, Gaiping; Jones, Matthew C.; Hurles, Matthew E.; Andrews, T. Daniel; Scott, Carol E.; Searle, Stephen; Ramser, Juliane; Whittaker, Adam; Deadman, Rebecca; Carter, Nigel P.; Hunt, Sarah E.; Chen, Rui; Cree, Andrew; Gunaratne, Preethi; Havlak, Paul; Hodgson, Anne; Metzker, Michael L.; Richards, Stephen; Scott, Graham; Steffen, David; Sodergren, Erica; Wheeler, David A.; Worley, Kim C.; Ainscough, Rachael; Ambrose, Kerrie D.; Ansari-Lari, M. Ali; Aradhya, Swaroop; Ashwell, Robert I. S.; Babbage, Anne K.; Bagguley, Claire L.; Ballabio, Andrea; Banerjee, Ruby; Barker, Gary E.; Barlow, Karen F.; Barrett, Ian P.; Bates, Karen N.; Beare, David M.; Beasley, Helen; Beasley, Oliver; Beck, Alfred; Bethel, Graeme; Blechschmidt, Karin; Brady, Nicola; Bray-Allen, Sarah; Bridgeman, Anne M.; Brown, Andrew J.; Brown, Mary J.; Bonnin, David; Bruford, Elspeth A.; Buhay, Christian; Burch, Paula; Burford, Deborah; Burgess, Joanne; Burrill, Wayne; Burton, John; Bye, Jackie M.; Carder, Carol; Carrel, Laura; Chako, Joseph; Chapman, Joanne C.; Chavez, Dean; Chen, Ellson; Chen, Guan; Chen, Yuan; Chen, Zhijian; Chinault, Craig; Ciccodicola, Alfredo; Clark, Sue Y.; Clarke, Graham; Clee, Chris M.; Clegg, Sheila; Clerc-Blankenburg, Kerstin; Clifford, Karen; Cobley, Vicky; Cole, Charlotte G.; Conquer, Jen S.; Corby, Nicole; Connor, Richard E.; David, Robert; Davies, Joy; Davis, Clay; Davis, John; Delgado, Oliver; DeShazo, Denise; Dhami, Pawandeep; Ding, Yan; Dinh, Huyen; Dodsworth, Steve; Draper, Heather; Dugan-Rocha, Shannon; Dunham, Andrew; Dunn, Matthew; Durbin, K. James; Dutta, Ireena; Eades, Tamsin; Ellwood, Matthew; Emery-Cohen, Alexandra; Errington, Helen; Evans, Kathryn L.; Faulkner, Louisa; Francis, Fiona; Frankland, John; Fraser, Audrey E.; Galgoczy, Petra; Gilbert, James; Gill, Rachel; Glöckner, Gernot; Gregory, Simon G.; Gribble, Susan; Griffiths, Coline; Grocock, Russell; Gu, Yanghong; Gwilliam, Rhian; Hamilton, Cerissa; Hart, Elizabeth A.; Hawes, Alicia; Heath, Paul D.; Heitmann, Katja; Hennig, Steffen; Hernandez, Judith; Hinzmann, Bernd; Ho, Sarah; Hoffs, Michael; Howden, Phillip J.; Huckle, Elizabeth J.; Hume, Jennifer; Hunt, Paul J.; Hunt, Adrienne R.; Isherwood, Judith; Jacob, Leni; Johnson, David; Jones, Sally; de Jong, Pieter J.; Joseph, Shirin S.; Keenan, Stephen; Kelly, Susan; Kershaw, Joanne K.; Khan, Ziad; Kioschis, Petra; Klages, Sven; Knights, Andrew J.; Kosiura, Anna; Kovar-Smith, Christie; Laird, Gavin K.; Langford, Cordelia; Lawlor, Stephanie; Leversha, Margaret; Lewis, Lora; Liu, Wen; Lloyd, Christine; Lloyd, David M.; Loulseged, Hermela; Loveland, Jane E.; Lovell, Jamieson D.; Lozado, Ryan; Lu, Jing; Lyne, Rachael; Ma, Jie; Maheshwari, Manjula; Matthews, Lucy H.; McDowall, Jennifer; McLaren, Stuart; McMurray, Amanda; Meidl, Patrick; Meitinger, Thomas; Milne, Sarah; Miner, George; Mistry, Shailesh L.; Morgan, Margaret; Morris, Sidney; Müller, Ines; Mullikin, James C.; Nguyen, Ngoc; Nordsiek, Gabriele; Nyakatura, Gerald; O’Dell, Christopher N.; Okwuonu, Geoffery; Palmer, Sophie; Pandian, Richard; Parker, David; Parrish, Julia; Pasternak, Shiran; Patel, Dina; Pearce, Alex V.; Pearson, Danita M.; Pelan, Sarah E.; Perez, Lesette; Porter, Keith M.; Ramsey, Yvonne; Reichwald, Kathrin; Rhodes, Susan; Ridler, Kerry A.; Schlessinger, David; Schueler, Mary G.; Sehra, Harminder K.; Shaw-Smith, Charles; Shen, Hua; Sheridan, Elizabeth M.; Shownkeen, Ratna; Skuce, Carl D.; Smith, Michelle L.; Sotheran, Elizabeth C.; Steingruber, Helen E.; Steward, Charles A.; Storey, Roy; Swann, R. Mark; Swarbreck, David; Tabor, Paul E.; Taudien, Stefan; Taylor, Tineace; Teague, Brian; Thomas, Karen; Thorpe, Andrea; Timms, Kirsten; Tracey, Alan; Trevanion, Steve; Tromans, Anthony C.; d’Urso, Michele; Verduzco, Daniel; Villasana, Donna; Waldron, Lenee; Wall, Melanie; Wang, Qiaoyan; Warren, James; Warry, Georgina L.; Wei, Xuehong; West, Anthony; Whitehead, Siobhan L.; Whiteley, Mathew N.; Wilkinson, Jane E.; Willey, David L.; Williams, Gabrielle; Williams, Leanne; Williamson, Angela; Williamson, Helen; Wilming, Laurens; Woodmansey, Rebecca L.; Wray, Paul W.; Yen, Jennifer; Zhang, Jingkun; Zhou, Jianling; Zoghbi, Huda; Zorilla, Sara; Buck, David; Reinhardt, Richard; Poustka, Annemarie; Rosenthal, André; Lehrach, Hans; Meindl, Alfons; Minx, Patrick J.; Hillier, LaDeana W.; Willard, Huntington F.; Wilson, Richard K.; Waterston, Robert H.; Rice, Catherine M.; Vaudin, Mark; Coulson, Alan; Nelson, David L.; Weinstock, George; Sulston, John E.; Durbin, Richard; Hubbard, Tim; Gibbs, Richard A.; Beck, Stephan; Rogers, Jane; Bentley, David R.

    2009-01-01

    The human X chromosome has a unique biology that was shaped by its evolution as the sex chromosome shared by males and females. We have determined 99.3% of the euchromatic sequence of the X chromosome. Our analysis illustrates the autosomal origin of the mammalian sex chromosomes, the stepwise process that led to the progressive loss of recombination between X and Y, and the extent of subsequent degradation of the Y chromosome. LINE1 repeat elements cover one-third of the X chromosome, with a distribution that is consistent with their proposed role as way stations in the process of X-chromosome inactivation. We found 1,098 genes in the sequence, of which 99 encode proteins expressed in testis and in various tumour types. A disproportionately high number of mendelian diseases are documented for the X chromosome. Of this number, 168 have been explained by mutations in 113 X-linked genes, which in many cases were characterized with the aid of the DNA sequence. PMID:15772651

  12. An X-linked Myh11-CreERT2 mouse line resulting from Y to X chromosome-translocation of the Cre allele.

    Science.gov (United States)

    Liao, Mingmei; Zhou, Junmei; Wang, Fen; Ali, Yasmin H; Chan, Kelvin L; Zou, Fei; Offermanns, Stefan; Jiang, Zhisheng; Jiang, Zhihua

    2017-09-01

    The Myh11-CreER T2 mouse line (Cre + ) has gained increasing application because of its high lineage specificity relative to other Cre drivers targeting smooth muscle cells (SMCs). This Cre allele, however, was initially inserted into the Y chromosome (X/Y Cre+ ), which excluded its application in female mice. Our group established a Cre + colony from male ancestors. Surprisingly, genotype screening identified female carriers that stably transmitted the Cre allele to the following generations. Crossbreeding experiments revealed a pattern of X-linked inheritance for the transgene (k > 1000), indicating that these female carries acquired the Cre allele through a mechanism of Y to X chromosome translocation. Further characterization demonstrated that in hemizygous X/X Cre+ mice Cre activity was restricted to a subset arterial SMCs, with Cre expression in arteries decreased by 50% compared to X/Y Cre+ mice. This mosaicism, however, diminished in homozygous X Cre+ /X Cre+ mice. In a model of aortic aneurysm induced by a SMC-specific Tgfbr1 deletion, the homozygous X Cre+ /X Cre+ Cre driver unmasked the aortic phenotype that is otherwise subclinical when driven by the hemizygous X/X Cre+ Cre line. In conclusion, the Cre allele carried by this female mouse line is located on the X chromosome and subjected to X-inactivation. The homozygous X Cre+ /X Cre+ mice produce uniform Cre activity in arterial SMCs. © 2017 Wiley Periodicals, Inc.

  13. Migration distance is positively associated with sex-linked genetic diversity in passerine birds

    Czech Academy of Sciences Publication Activity Database

    Gohli, J.; Lifjeld, J. T.; Albrecht, Tomáš

    2016-01-01

    Roč. 28, č. 1 (2016), s. 42-52 ISSN 0394-9370 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : autosomes * female promiscuity * introns * seasonal migration * Z chromosome Subject RIV: EG - Zoology Impact factor: 1.582, year: 2016

  14. Identifying new sex-linked genes through BAC sequencing in the dioecious plant Silene latifolia

    Czech Academy of Sciences Publication Activity Database

    Blavet, N.; Blavet, Hana; Muyle, A.; Kaefer, J.; Čegan, Radim; Deschamps, C.; Zemp, N.; Mousset, S.; Aubourg, S.; Bergero, R.; Charlesworth, D.; Hobza, Roman; Widmer, A.; Marais, G.A.B.

    2015-01-01

    Roč. 16, JUL 2015 (2015) ISSN 1471-2164 R&D Projects: GA ČR(CZ) GAP501/12/2220 Institutional support: RVO:68081707 Keywords : Y-CHROMOSOME * EVOLUTION * REARRANGEMENTS Subject RIV: BO - Biophysics Impact factor: 3.867, year: 2015

  15. Fully automated pipeline for detection of sex linked genes using RNA-Seq data

    Czech Academy of Sciences Publication Activity Database

    Michalovová, Monika; Kubát, Zdeněk; Hobza, Roman; Vyskot, Boris; Kejnovský, Eduard

    2015-01-01

    Roč. 16, č. 78 (2015) ISSN 1471-2105 R&D Projects: GA ČR(CZ) GBP501/12/G090; GA MŠk(CZ) LM2010005 Institutional support: RVO:68081707 Keywords : SILENE-LATIFOLIA * RUMEX-ACETOSA * Y-CHROMOSOME Subject RIV: BO - Biophysics; EF - Botanics (UEB-Q) Impact factor: 2.435, year: 2015

  16. Differentiation of sex chromosomes and karyotypic evolution in the eye-lid geckos (Squamata: Gekkota: Eublepharidae), a group with different modes of sex determination

    Czech Academy of Sciences Publication Activity Database

    Pokorná, M.; Rábová, Marie; Ráb, Petr; Ferguson-Smith, M. A.; Rens, W.; Kratochvíl, L.

    2010-01-01

    Roč. 18, č. 6 (2010), s. 809-820 ISSN 0967-3849 R&D Projects: GA ČR GAP506/10/0718; GA MŠk LC06073 Grant - others:GA ČR(CZ) GP206/06/P282 Program:GP Institutional research plan: CEZ:AV0Z50450515 Keywords : reptile cytogenetics * FISH * neo- sex hromosomes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.130, year: 2010

  17. Disparity in population differentiation of sex-linked and autosomal variation in sibling species of the Jaera albifrons (Isopoda) complex

    DEFF Research Database (Denmark)

    Siegismund, H R

    2003-01-01

    The genetic variation at four enzyme loci is described for 22 populations of three Jaera species--J. albifrons, J. ischiosetosa, and J. praehirsuta--in the J. albifrons complex (Crustacea, Isopoda) in Denmark. The variation at three of the loci is similar, with the allele frequency spectra close...... to each other in all three species. An evolutionary tree based on the variation at these three loci revealed that the populations from the different species are completely intermixed in the tree. This was supported by hierarchical F-statistics where the between-species component was zero. At a fourth....... An evolutionary tree for this locus partitions the populations into separate groups and a hierarchical F-statistic has a between-species component of about 50%. The results are attributed to introgression with a higher rate for autosomes than for sex chromosomes....

  18. Mode of action, origin and structure of the Paternal Sex Ratio chromosome in the parasitoid wasp Trichogramma kaykai

    NARCIS (Netherlands)

    Vugt, van J.J.F.A.

    2005-01-01

    Selfish genetic elements are defined as genetic elements that have a replication advantage relative to the rest of the genome. They are ubiquitous in nature and were extensively reported for almost all species studied so far. A special type of selfish genetic element, the sex ratio distorter, is

  19. Anticipated stigma and blameless guilt: Mothers' evaluation of life with the sex-linked disorder, hypohidrotic ectodermal dysplasia (XHED)

    OpenAIRE

    Clarke, Angus

    2016-01-01

    Practical experience of a genetic disorder may influence how parents approach reproduction, if they know their child may be affected by an inherited condition. One important aspect of this practical experience is the stigmatisation which family members may experience or witness. We outline the concept of stigma and how it affects those in families with a condition that impacts upon physical appearance. We then consider the accounts given by females in families affected by the rare sex-linked ...

  20. Co-regulation analysis of closely linked genes identifies a highly recurrent gain on chromosome 17q25.3 in prostate cancer

    International Nuclear Information System (INIS)

    Bermudo, Raquel; Martínez-A, Carlos; Ortiz, Ángel R; Fernández, Pedro L; Thomson, Timothy M; Abia, David; Ferrer, Berta; Nayach, Iracema; Benguria, Alberto; Zaballos, Ángel; Rey, Javier del; Miró, Rosa; Campo, Elías

    2008-01-01

    Transcriptional profiling of prostate cancer (PC) has unveiled new markers of neoplasia and allowed insights into mechanisms underlying this disease. Genomewide analyses have also identified new chromosomal abnormalities associated with PC. The combination of both classes of data for the same sample cohort might provide better criteria for identifying relevant factors involved in neoplasia. Here we describe transcriptional signatures identifying distinct normal and tumoral prostate tissue compartments, and the inference and demonstration of a new, highly recurrent copy number gain on chromosome 17q25.3. We have applied transcriptional profiling to tumoral and non-tumoral prostate samples with relatively homogeneous epithelial representations as well as pure stromal tissue from peripheral prostate and cultured cell lines, followed by quantitative RT-PCR validations and immunohistochemical analysis. In addition, we have performed in silico colocalization analysis of co-regulated genes and validation by fluorescent in situ hybridization (FISH). The transcriptomic analysis has allowed us to identify signatures corresponding to non-tumoral luminal and tumoral epithelium, basal epithelial cells, and prostate stromal tissue. In addition, in silico analysis of co-regulated expression of physically linked genes has allowed us to predict the occurrence of a copy number gain at chromosomal region 17q25.3. This computational inference was validated by fluorescent in situ hybridization, which showed gains in this region in over 65% of primary and metastatic tumoral samples. Our approach permits to directly link gene copy number variations with transcript co-regulation in association with neoplastic states. Therefore, transcriptomic studies of carefully selected samples can unveil new diagnostic markers and transcriptional signatures highly specific of PC, and lead to the discovery of novel genomic abnormalities that may provide additional insights into the causes and mechanisms

  1. Hepatitis A outbreak among MSM linked to casual sex and gay saunas in Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Mazick, A; Howitz, Michael Frantz; Rex, S

    2005-01-01

    .2-26.9). Eleven of 18 cases and 14/62 controls had sex in gay saunas (ORMH 4.2, 95% CI 1.5-11.5). Sex at private homes appeared to be protective (ORMH 0.2, 95% CI 0.1-0.7). Casual sex including sex in gay saunas was an important risk factor for the spread of HAV among MSM in Copenhagen. The results...... are in accordance with findings in other European outbreaks. As the general immunity to hepatitis A decreases and the outbreak potential increases, we recommend health education and hepatitis A vaccination to all MSM not living in monogamous relationships, especially if they visit gay saunas or other places...

  2. Origin and domestication of papaya Yh chromosome

    Science.gov (United States)

    VanBuren, Robert; Zeng, Fanchang; Chen, Cuixia; Zhang, Jisen; Wai, Ching Man; Han, Jennifer; Aryal, Rishi; Gschwend, Andrea R.; Wang, Jianping; Na, Jong-Kuk; Huang, Lixian; Zhang, Lingmao; Miao, Wenjing; Gou, Jiqing; Arro, Jie; Guyot, Romain; Moore, Richard C.; Wang, Ming-Li; Zee, Francis; Charlesworth, Deborah; Moore, Paul H.; Yu, Qingyi; Ming, Ray

    2015-01-01

    Sex in papaya is controlled by a pair of nascent sex chromosomes. Females are XX, and two slightly different Y chromosomes distinguish males (XY) and hermaphrodites (XYh). The hermaphrodite-specific region of the Yh chromosome (HSY) and its X chromosome counterpart were sequenced and analyzed previously. We now report the sequence of the entire male-specific region of the Y (MSY). We used a BAC-by-BAC approach to sequence the MSY and resequence the Y regions of 24 wild males and the Yh regions of 12 cultivated hermaphrodites. The MSY and HSY regions have highly similar gene content and structure, and only 0.4% sequence divergence. The MSY sequences from wild males include three distinct haplotypes, associated with the populations’ geographic locations, but gene flow is detected for other genomic regions. The Yh sequence is highly similar to one Y haplotype (MSY3) found only in wild dioecious populations from the north Pacific region of Costa Rica. The low MSY3-Yh divergence supports the hypothesis that hermaphrodite papaya is a product of human domestication. We estimate that Yh arose only ∼4000 yr ago, well after crop plant domestication in Mesoamerica >6200 yr ago but coinciding with the rise of the Maya civilization. The Yh chromosome has lower nucleotide diversity than the Y, or the genome regions that are not fully sex-linked, consistent with a domestication bottleneck. The identification of the ancestral MSY3 haplotype will expedite investigation of the mutation leading to the domestication of the hermaphrodite Yh chromosome. In turn, this mutation should identify the gene that was affected by the carpel-suppressing mutation that was involved in the evolution of males. PMID:25762551

  3. Only a minority of sex chromosome abnormalities are detected by a national prenatal screening program for Down syndrome

    DEFF Research Database (Denmark)

    Viuff, Mette Hansen; Krag, Kirstine Stochholm; Uldbjerg, Niels

    2015-01-01

    significantly higher NT and lower PAPP-A compared with controls (all P legal abortion rate was high for all four syndromes (47,XXX: 24%; 47,XYY: 29%; Klinefelter syndrome: 48%, TS: 84%). For SCA fetuses carried to term, only TS fetuses had consistently lower birthweights...... and placenta weights than non-SCA controls (both P = 0.0001). A few SCA cases localized in DCCR could not be found in DFMD (n = 16). LIMITATIONS, REASON FOR CAUTION: Controls were matched on sex of the fetus of cases, meaning that all electively aborted fetuses (before week 12) were excluded, possibly reducing...

  4. X chromosome dosage compensation via enhanced transcriptional elongation in Drosophila.

    Science.gov (United States)

    Larschan, Erica; Bishop, Eric P; Kharchenko, Peter V; Core, Leighton J; Lis, John T; Park, Peter J; Kuroda, Mitzi I

    2011-03-03

    The evolution of sex chromosomes has resulted in numerous species in which females inherit two X chromosomes but males have a single X, thus requiring dosage compensation. MSL (Male-specific lethal) complex increases transcription on the single X chromosome of Drosophila males to equalize expression of X-linked genes between the sexes. The biochemical mechanisms used for dosage compensation must function over a wide dynamic range of transcription levels and differential expression patterns. It has been proposed that the MSL complex regulates transcriptional elongation to control dosage compensation, a model subsequently supported by mapping of the MSL complex and MSL-dependent histone 4 lysine 16 acetylation to the bodies of X-linked genes in males, with a bias towards 3' ends. However, experimental analysis of MSL function at the mechanistic level has been challenging owing to the small magnitude of the chromosome-wide effect and the lack of an in vitro system for biochemical analysis. Here we use global run-on sequencing (GRO-seq) to examine the specific effect of the MSL complex on RNA Polymerase II (RNAP II) on a genome-wide level. Results indicate that the MSL complex enhances transcription by facilitating the progression of RNAP II across the bodies of active X-linked genes. Improving transcriptional output downstream of typical gene-specific controls may explain how dosage compensation can be imposed on the diverse set of genes along an entire chromosome.

  5. Screening and identification of a microsatellite marker associated with sex in Wami tilapia, Oreochromis urolepis hornorum.

    Science.gov (United States)

    Zhu, Huaping; Liu, Zhigang; Lu, Maixin; Gao, Fengying; Ke, Xiaoli; Ma, Dongmei; Huang, Zhanghan; Cao, Jianmeng; Wang, Miao

    2016-06-01

    In this study, primer pairs of 15 microsatellite markers associated with sex determination of tilapia were selected and amplified in Wami tilapia, Oreochromis urolepis hornorum. While one marker, UNH168, on linkage group 3 (LG3) was associated (P tilapia chromosome pair (chromosome 1, equivalent to LG3). This sex-linked microsatellite marker could potentially be used for marker-assisted selection in tilapia breeding programmes to produce monosex male tilapia.

  6. Sulcal Morphology and Volume of Broca's Area Linked to Handedness and Sex

    Science.gov (United States)

    Powell, Joanne L.; Kemp, Graham J.; Roberts, Neil; Garcia-Finana, Marta

    2012-01-01

    We investigated the effect of handedness and sex on: (i) sulcal contours defining PO and PTR and (ii) volume estimates of PO and PTR subfields in 40 left- and 42 right-handers. Results show an effect of handedness on discontinuity of the inferior frontal sulcus (IFS: P less than 0.01). Discontinuity of IFS was observed in: 43% left- and 62% right…

  7. Mapping of the X-linked cataract (Xcat) mutation, the gene implicated in the Nance Horan syndrome, on the mouse X chromosome.

    Science.gov (United States)

    Stambolian, D; Favor, J; Silvers, W; Avner, P; Chapman, V; Zhou, E

    1994-07-15

    The Xcat mutation in the mouse, an X-linked inherited disorder, is characterized by the congenital onset of cataracts. The cataracts have morphologies similar to those of cataracts found in the human Nance Horan (X-linked cataract dental) syndrome, suggesting that Xcat is an animal model for Nance Horan. The Xcat mutation provides an opportunity to investigate, at the molecular level, the pathogenesis of cataract. As a first step to cloning the Xcat gene, we report the localization of the Xcat mutation with respect to known molecular markers on the mouse X chromosome. Back-cross progeny carrying the Xcat mutation were obtained from an interspecific cross. Genomic DNA from each mouse was subjected to Southern and PCR analysis to identify restriction fragment length polymorphisms and simple sequence length polymorphisms, respectively. Our results refine the location of Xcat to a 2-cM region, eliminate several genes from consideration as the Xcat mutation, identify molecular probes tightly linked with Xcat, and suggest candidate genes responsible for the Xcat phenotype.

  8. Sequencing and association analysis of the type 1 diabetes – linked region on chromosome 10p12-q11

    Directory of Open Access Journals (Sweden)

    Barratt Bryan J

    2007-05-01

    Full Text Available Abstract Background In an effort to locate susceptibility genes for type 1 diabetes (T1D several genome-wide linkage scans have been undertaken. A chromosomal region designated IDDM10 retained genome-wide significance in a combined analysis of the main linkage scans. Here, we studied sequence polymorphisms in 23 Mb on chromosome 10p12-q11, including the putative IDDM10 region, to identify genes associated with T1D. Results Initially, we resequenced the functional candidate genes, CREM and SDF1, located in this region, genotyped 13 tag single nucleotide polymorphisms (SNPs and found no association with T1D. We then undertook analysis of the whole 23 Mb region. We constructed and sequenced a contig tile path from two bacterial artificial clone libraries. By comparison with a clone library from an unrelated person used in the Human Genome Project, we identified 12,058 SNPs. We genotyped 303 SNPs and 25 polymorphic microsatellite markers in 765 multiplex T1D families and followed up 22 associated polymorphisms in up to 2,857 families. We found nominal evidence of association in six loci (P = 0.05 – 0.0026, located near the PAPD1 gene. Therefore, we resequenced 38.8 kb in this region, found 147 SNPs and genotyped 84 of them in the T1D families. We also tested 13 polymorphisms in the PAPD1 gene and in five other loci in 1,612 T1D patients and 1,828 controls from the UK. Overall, only the D10S193 microsatellite marker located 28 kb downstream of PAPD1 showed nominal evidence of association in both T1D families and in the case-control sample (P = 0.037 and 0.03, respectively. Conclusion We conclude that polymorphisms in the CREM and SDF1 genes have no major effect on T1D. The weak T1D association that we detected in the association scan near the PAPD1 gene may be either false or due to a small genuine effect, and cannot explain linkage at the IDDM10 region.

  9. Identification of the linkage group of the Z sex chromosomes of the sand lizard (Lacerta agilis, Lacertidae) and elucidation of karyotype evolution in lacertid lizards.

    Science.gov (United States)

    Srikulnath, Kornsorn; Matsubara, Kazumi; Uno, Yoshinobu; Nishida, Chizuko; Olsson, Mats; Matsuda, Yoichi

    2014-12-01

    The sand lizard (Lacerta agilis, Lacertidae) has a chromosome number of 2n = 38, with 17 pairs of acrocentric chromosomes, one pair of microchromosomes, a large acrocentric Z chromosome, and a micro-W chromosome. To investigate the process of karyotype evolution in L. agilis, we performed chromosome banding and fluorescent in situ hybridization for gene mapping and constructed a cytogenetic map with 86 functional genes. Chromosome banding revealed that the Z chromosome is the fifth largest chromosome. The cytogenetic map revealed homology of the L. agilis Z chromosome with chicken chromosomes 6 and 9. Comparison of the L. agilis cytogenetic map with those of four Toxicofera species with many microchromosomes (Elaphe quadrivirgata, Varanus salvator macromaculatus, Leiolepis reevesii rubritaeniata, and Anolis carolinensis) showed highly conserved linkage homology of L. agilis chromosomes (LAG) 1, 2, 3, 4, 5(Z), 7, 8, 9, and 10 with macrochromosomes and/or macrochromosome segments of the four Toxicofera species. Most of the genes located on the microchromosomes of Toxicofera were localized to LAG6, small acrocentric chromosomes (LAG11-18), and a microchromosome (LAG19) in L. agilis. These results suggest that the L. agilis karyotype resulted from frequent fusions of microchromosomes, which occurred in the ancestral karyotype of Toxicofera and led to the disappearance of microchromosomes and the appearance of many small macrochromosomes.

  10. DEHP exposure in utero disturbs sex determination and is potentially linked with precocious puberty in female mice

    International Nuclear Information System (INIS)

    Wang, Yongan; Yang, Qing; Liu, Wei; Yu, Mingxi; Zhang, Zhou; Cui, Xiaoyu

    2016-01-01

    Human's ubiquitous exposure to di (2-ethylhexyl) phthalate (DEHP) is thought to be associated with female reproductive toxicity. Previous studies found that DEHP inhibited follicle growth and decreased estradiol levels in adult female mice. However, limited information is available on the link between in utero DEHP exposure and ovarian development in female mouse offspring. The present study evaluates the disturbances in regulatory genes involved in female sex determination and the ovarian outcomes in fetal and postnatal female mice treated with in utero DEHP exposure. Pregnant mice were exposed to DEHP by gavage, with the dosage regime beginning at human relevant exposure levels. After in utero DEHP exposure, increased follicular atresia was observed in the female pups at postnatal days (PND) 21. Foxl2 expression was significantly upregulated, and Fst was significantly downregulated by DEHP above 2 mg/kg/d at PND 1 and 21. This suggests that lesion of granulosa cell differentiation and disturbance of follicle development in postnatal female mice. The expression of Cyp11a1 and Star were significantly downregulated by in utero DEHP exposure, indicating effects on estradiol biosynthesis. The female sex determination pathway was disturbed in fetus by DEHP at 2 mg/kg/d and above during the critical time window of sex determination causing significant upregulation of Foxl2, Wnt4, β-catenin and Fst. Furthermore, the increased expression of Wnt4 was supported by whole-mount in situ hybridization (WISH). These results suggest a possible association between in utero DEHP exposure and precocious puberty in the postnatal life of mice offspring, where disturbance of the sex determination regulating pathway acted as an important mechanism. - Highlights: • Maternal exposure to di (2-ethylhexyl) phthalate disturbs fetus sex determination. • DEHP upregulated Foxl2 expression potentially disturbs postnatal granulosa cell differentiation. • DEHP accelerated medulla

  11. DEHP exposure in utero disturbs sex determination and is potentially linked with precocious puberty in female mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yongan [Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian, Liaoning 116024 (China); Yang, Qing [School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116024 (China); Liu, Wei, E-mail: liu_wei@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian, Liaoning 116024 (China); Yu, Mingxi; Zhang, Zhou; Cui, Xiaoyu [Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian, Liaoning 116024 (China)

    2016-09-15

    Human's ubiquitous exposure to di (2-ethylhexyl) phthalate (DEHP) is thought to be associated with female reproductive toxicity. Previous studies found that DEHP inhibited follicle growth and decreased estradiol levels in adult female mice. However, limited information is available on the link between in utero DEHP exposure and ovarian development in female mouse offspring. The present study evaluates the disturbances in regulatory genes involved in female sex determination and the ovarian outcomes in fetal and postnatal female mice treated with in utero DEHP exposure. Pregnant mice were exposed to DEHP by gavage, with the dosage regime beginning at human relevant exposure levels. After in utero DEHP exposure, increased follicular atresia was observed in the female pups at postnatal days (PND) 21. Foxl2 expression was significantly upregulated, and Fst was significantly downregulated by DEHP above 2 mg/kg/d at PND 1 and 21. This suggests that lesion of granulosa cell differentiation and disturbance of follicle development in postnatal female mice. The expression of Cyp11a1 and Star were significantly downregulated by in utero DEHP exposure, indicating effects on estradiol biosynthesis. The female sex determination pathway was disturbed in fetus by DEHP at 2 mg/kg/d and above during the critical time window of sex determination causing significant upregulation of Foxl2, Wnt4, β-catenin and Fst. Furthermore, the increased expression of Wnt4 was supported by whole-mount in situ hybridization (WISH). These results suggest a possible association between in utero DEHP exposure and precocious puberty in the postnatal life of mice offspring, where disturbance of the sex determination regulating pathway acted as an important mechanism. - Highlights: • Maternal exposure to di (2-ethylhexyl) phthalate disturbs fetus sex determination. • DEHP upregulated Foxl2 expression potentially disturbs postnatal granulosa cell differentiation. • DEHP accelerated medulla

  12. XX Disorder of Sex Development is associated with an insertion on chromosome 9 and downregulation of RSPO1 in dogs (Canis lupus familiaris.

    Directory of Open Access Journals (Sweden)

    Vicki N Meyers-Wallen

    Full Text Available Remarkable progress has been achieved in understanding the mechanisms controlling sex determination, yet the cause for many Disorders of Sex Development (DSD remains unknown. Of particular interest is a rare XX DSD subtype in which individuals are negative for SRY, the testis determining factor on the Y chromosome, yet develop testes or ovotestes, and both of these phenotypes occur in the same family. This is a naturally occurring disorder in humans (Homo sapiens and dogs (C. familiaris. Phenotypes in the canine XX DSD model are strikingly similar to those of the human XX DSD subtype. The purposes of this study were to identify 1 a variant associated with XX DSD in the canine model and 2 gene expression alterations in canine embryonic gonads that could be informative to causation. Using a genome wide association study (GWAS and whole genome sequencing (WGS, we identified a variant on C. familiaris autosome 9 (CFA9 that is associated with XX DSD in the canine model and in affected purebred dogs. This is the first marker identified for inherited canine XX DSD. It lies upstream of SOX9 within the canine ortholog for the human disorder, which resides on 17q24. Inheritance of this variant indicates that XX DSD is a complex trait in which breed genetic background affects penetrance. Furthermore, the homozygous variant genotype is associated with embryonic lethality in at least one breed. Our analysis of gene expression studies (RNA-seq and PRO-seq in embryonic gonads at risk of XX DSD from the canine model identified significant RSPO1 downregulation in comparison to XX controls, without significant upregulation of SOX9 or other known testis pathway genes. Based on these data, a novel mechanism is proposed in which molecular lesions acting upstream of RSPO1 induce epigenomic gonadal mosaicism.

  13. XX Disorder of Sex Development is associated with an insertion on chromosome 9 and downregulation of RSPO1 in dogs (Canis lupus familiaris).

    Science.gov (United States)

    Meyers-Wallen, Vicki N; Boyko, Adam R; Danko, Charles G; Grenier, Jennifer K; Mezey, Jason G; Hayward, Jessica J; Shannon, Laura M; Gao, Chuan; Shafquat, Afrah; Rice, Edward J; Pujar, Shashikant; Eggers, Stefanie; Ohnesorg, Thomas; Sinclair, Andrew H

    2017-01-01

    Remarkable progress has been achieved in understanding the mechanisms controlling sex determination, yet the cause for many Disorders of Sex Development (DSD) remains unknown. Of particular interest is a rare XX DSD subtype in which individuals are negative for SRY, the testis determining factor on the Y chromosome, yet develop testes or ovotestes, and both of these phenotypes occur in the same family. This is a naturally occurring disorder in humans (Homo sapiens) and dogs (C. familiaris). Phenotypes in the canine XX DSD model are strikingly similar to those of the human XX DSD subtype. The purposes of this study were to identify 1) a variant associated with XX DSD in the canine model and 2) gene expression alterations in canine embryonic gonads that could be informative to causation. Using a genome wide association study (GWAS) and whole genome sequencing (WGS), we identified a variant on C. familiaris autosome 9 (CFA9) that is associated with XX DSD in the canine model and in affected purebred dogs. This is the first marker identified for inherited canine XX DSD. It lies upstream of SOX9 within the canine ortholog for the human disorder, which resides on 17q24. Inheritance of this variant indicates that XX DSD is a complex trait in which breed genetic background affects penetrance. Furthermore, the homozygous variant genotype is associated with embryonic lethality in at least one breed. Our analysis of gene expression studies (RNA-seq and PRO-seq) in embryonic gonads at risk of XX DSD from the canine model identified significant RSPO1 downregulation in comparison to XX controls, without significant upregulation of SOX9 or other known testis pathway genes. Based on these data, a novel mechanism is proposed in which molecular lesions acting upstream of RSPO1 induce epigenomic gonadal mosaicism.

  14. Hepatitis A outbreak among MSM linked to casual sex and gay saunas in Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Mazick, A; Howitz, M; Rex, S

    2005-01-01

    During an outbreak of hepatitis A predominantly among men who have sex with men (MSM) in Copenhagen, Denmark, in 2004, we did a case-control study to determine risk factors for infection. A case was an MSM >17 years, living in Copenhagen, with IgM positive hepatitis A infection diagnosed between...... June and August 2004, and without a household contact with a hepatitis A case before onset of illness. Controls were selected at the Copenhagen Pride Festival. The study included 18 cases and 64 controls. Sixteen of 18 cases and 36/63 controls had sex with casual partners (ORMH 5.6, 95% CI 1...... are in accordance with findings in other European outbreaks. As the general immunity to hepatitis A decreases and the outbreak potential increases, we recommend health education and hepatitis A vaccination to all MSM not living in monogamous relationships, especially if they visit gay saunas or other places...

  15. Does more mean better? Sibling sex composition and the link between family size and children's quality

    OpenAIRE

    Baez, Javier E.

    2008-01-01

    Exogenous variation in fertility from parental preferences for sex-mix among their children is used to identify the causal effect of family size on several measures associated with either the allocation of resources towards children within the household or the outcomes of these investments. Results using data from Colombia suggest that family size has negative effects on average child quality. Children from larger families have accumulated almost 1 year less of education, are less likely to e...

  16. Tissue- and stage-dependent dosage compensation on the Neo-X chromosome in drosophila pseudoobscura

    KAUST Repository

    Nozawa, Masafumi; Fukuda, Nana; Ikeo, Kazuho; Gojobori, Takashi

    2013-01-01

    Sex chromosome dosage compensation (DC) is widely accepted in various organisms. This concept is mostly supported by comparisons of gene expression between chromosomes and between sexes. However, genes on the X chromosome and autosomes are mostly

  17. Implementation of an electronic fingerprint-linked data collection system: a feasibility and acceptability study among Zambian female sex workers.

    Science.gov (United States)

    Wall, Kristin M; Kilembe, William; Inambao, Mubiana; Chen, Yi No; Mchoongo, Mwaka; Kimaru, Linda; Hammond, Yuna Tiffany; Sharkey, Tyronza; Malama, Kalonde; Fulton, T Roice; Tran, Alex; Halumamba, Hanzunga; Anderson, Sarah; Kishore, Nishant; Sarwar, Shawn; Finnegan, Trisha; Mark, David; Allen, Susan A

    2015-06-27

    Patient identification within and between health services is an operational challenge in many resource-limited settings. When following HIV risk groups for service provision and in the context of vaccine trials, patient misidentification can harm patient care and bias trial outcomes. Electronic fingerprinting has been proposed to identify patients over time and link patient data between health services. The objective of this study was to determine 1) the feasibility of implementing an electronic-fingerprint linked data capture system in Zambia and 2) the acceptability of this system among a key HIV risk group: female sex workers (FSWs). Working with Biometrac, a US-based company providing biometric-linked healthcare platforms, an electronic fingerprint-linked data capture system was developed for use by field recruiters among Zambian FSWs. We evaluated the technical feasibility of the system for use in the field in Zambia and conducted a pilot study to determine the acceptability of the system, as well as barriers to uptake, among FSWs. We found that implementation of an electronic fingerprint-linked patient tracking and data collection system was feasible in this relatively resource-limited setting (false fingerprint matching rate of 1/1000 and false rejection rate of lodges) could be addressed by recruiting women during less busy hours, in their own homes, in the presence of "Queen Mothers" (FSW organizers), or in the presence of a FSW that has already been fingerprinted. Our findings have major implications for key population research and improved health services provision. However, more work needs to be done to increase the acceptability of the electronic fingerprint-linked data capture system during field recruitment. This study indicated several potential avenues that will be explored to increase acceptability.

  18. Sex-specific expression of the X-linked histone demethylase gene Jarid1c in brain.

    Directory of Open Access Journals (Sweden)

    Jun Xu

    Full Text Available Jarid1c, an X-linked gene coding for a histone demethylase, plays an important role in brain development and function. Notably, JARID1C mutations cause mental retardation and increased aggression in humans. These phenotypes are consistent with the expression patterns we have identified in mouse brain where Jarid1c mRNA was detected in hippocampus, hypothalamus, and cerebellum. Jarid1c expression and associated active histone marks at its 5'end are high in P19 neurons, indicating that JARID1C demethylase plays an important role in differentiated neuronal cells. We found that XX mice expressed Jarid1c more highly than XY mice, independent of their gonadal types (testes versus ovaries. This increased expression in XX mice is consistent with Jarid1c escape from X inactivation and is not compensated by expression from the Y-linked paralogue Jarid1d, which is expressed at a very low level compared to the X paralogue in P19 cells. Our observations suggest that sex-specific expression of Jarid1c may contribute to sex differences in brain function.

  19. Chlorhexidine rinse for prevention of urethritis in men linked to oral sex

    Directory of Open Access Journals (Sweden)

    Kolahi Jafar

    2010-06-01

    Full Text Available Abstract Background Oral sex among teenagers is on the rise. Similarity between the oral flora and organisms recovered from nongonococcal urethritis and prostatitis, points to retrograde entry of bacteria from oral cavity into the urethra following insertive oral intercourse. Presentation of the hypothesis Chlorhexidine has a wide spectrum of anti-bactericidal activity encompassing gram positive and negative bacteria. It is also effective against HIV and HBV. It produced large and prolonged reductions in salivary bacterial counts within 7-h of its use. Hence, it would seem logic to postulate that rinsing with chlorhexidine before oral sex will be effective for prevention of retrograde entry of bacteria from oral cavity into the urethra. The recommendation for rinsing will be: 15 ml of a 0.12% or 10 ml of 0.2% chlorhexidine rinse for 30 seconds. Also other drug delivery systems such as chlorhexidine chewing gum or spray can be used. Testing the hypothesis Men suffering from recurrent nongonococcal urethritis or prostatitis are good subjects for testing the hypothesis. They perform genital safe sex via consistent use of condom. Yet they generally received unprotected insertive oral intercourse. Chlorhexidine can be used for prevention of recurrences of the disease. Implications of the hypothesis The chlorhexidine will be a new, easy, attractive and effective method for reduction of nongonococcal urethritis, prostatitis and epidydimitis following insertive oral intercourse. It is poorly absorbed from skin, mucosa and gastrointestinal tract indicating systemic safety of chlorhexidine. The agent does not cause any bacterial resistance and supra-infection.

  20. Autosomal and sex-linked microsatellite loci in the green oak leaf roller Tortrix viridana L.

    NARCIS (Netherlands)

    Schroeder, H.C.; Arens, P.F.P.; Smulders, M.J.M.

    2009-01-01

    Eight microsatellite markers were developed for the lepidopteran species Tortrix viridana using an enrichment protocol. The loci were highly variable with number of alleles ranging from four to 38. Six of the eight loci were in Hardy¿Weinberg equilibrium. The other two were linked to the

  1. Close linkage of the locus for X chromosome-linked severe combined immunodeficiency to polymorphic DNA markers in Xq11-q13

    International Nuclear Information System (INIS)

    de Saint Basile, G.; Arveiler, B.; Oberle, I.

    1987-01-01

    The gene for X chromosome-linked severe combined immunodeficiency (SCID), a disease characterized by a block in early T-cell differentiation, has been mapped to the region Xq11-q13 by linkage analysis with restriction fragment length polymorphisms. High logarithm of odds (lod) scores were obtained with the marker 19.2 (DXS3) and with the marker cpX73 (DXS159) that showed complete cosegregation with the disease locus in the informative families analyzed. Other significant linkages were obtained with several markers from Xq11 to q22. With the help of a recently developed genetic map of the region, it was possible to perform multipoint linkage analysis, and the most likely genetic order is DXS1-(SCID, DXS159)-DXYS1-DXYS12-DXS3, with a maximum multipoint logarithm of odds score of 11.0. The results demonstrate that the SCID locus (gene symbol IMD4) is not closely linked to the locus of Bruton's agammaglobulinemia (a defect in B-cell maturation). They also provide a way for a better estimation of risk for carrier and antenatal diagnosis

  2. The human sexual response cycle: brain imaging evidence linking sex to other pleasures.

    Science.gov (United States)

    Georgiadis, J R; Kringelbach, M L

    2012-07-01

    Sexual behavior is critical to species survival, yet comparatively little is known about the neural mechanisms in the human brain. Here we systematically review the existing human brain imaging literature on sexual behavior and show that the functional neuroanatomy of sexual behavior is comparable to that involved in processing other rewarding stimuli. Sexual behavior clearly follows the established principles and phases for wanting, liking and satiety involved in the pleasure cycle of other rewards. The studies have uncovered the brain networks involved in sexual wanting or motivation/anticipation, as well as sexual liking or arousal/consummation, while there is very little data on sexual satiety or post-orgasmic refractory period. Human sexual behavior also interacts with other pleasures, most notably social interaction and high arousal states. We discuss the changes in the underlying brain networks supporting sexual behavior in the context of the pleasure cycle, the changes to this cycle over the individual's life-time and the interactions between them. Overall, it is clear from the data that the functional neuroanatomy of sex is very similar to that of other pleasures and that it is unlikely that there is anything special about the brain mechanisms and networks underlying sex. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. A History of the Discovery of Random X Chromosome Inactivation in the Human Female and its Significance

    Directory of Open Access Journals (Sweden)

    Sophia Balderman

    2011-07-01

    Full Text Available Genetic determinants of sex in placental mammals developed by the evolution of primordial autosomes into the male and female sex chromosomes. The Y chromosome determines maleness by the action of the gene SRY, which encodes a protein that initiates a sequence of events prompting the embryonic gonads to develop into testes. The X chromosome in the absence of a Y chromosome results in a female by permitting the conversion of the embryonic gonads into ovaries. We trace the historical progress that resulted in the discovery that one X chromosome in the female is randomly inactivated in early embryogenesis, accomplishing approximate equivalency of X chromosome gene dosage in both sexes. This event results in half of the somatic cells in a tissue containing proteins encoded by the genes of the maternal X chromosome and half having proteins encoded by the genes of the paternal X chromosome, on average, accounting for the phenotype of a female heterozygote with an X chromosome mutation. The hypothesis of X chromosome inactivation as a random event early in embryogenesis was first described as a result of studies of variegated coat color in female mice. Similar results were found in women using the X chromosome-linked gene, glucose-6-phosphate dehydrogenase, studied in red cells. The random inactivation of the X chromosome-bearing genes for isoenzyme types A and B of glucose-6-phosphate dehydrogenase was used to establish the clonal origin of neoplasms in informative women with leiomyomas. Behind these discoveries are the stories of the men and women scientists whose research enlightened these aspects of X chromosome function and their implication for medicine.

  4. Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

    Directory of Open Access Journals (Sweden)

    Sebastian Pita

    2013-05-01

    Full Text Available In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae. The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome or both sex chromosomes (X and Y chromosomes. This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

  5. X Chromosome Dose and Sex Bias in Autoimmune Diseases: Increased Prevalence of 47,XXX in Systemic Lupus Erythematosus and Sjögren's Syndrome.

    Science.gov (United States)

    Liu, Ke; Kurien, Biji T; Zimmerman, Sarah L; Kaufman, Kenneth M; Taft, Diana H; Kottyan, Leah C; Lazaro, Sara; Weaver, Carrie A; Ice, John A; Adler, Adam J; Chodosh, James; Radfar, Lida; Rasmussen, Astrid; Stone, Donald U; Lewis, David M; Li, Shibo; Koelsch, Kristi A; Igoe, Ann; Talsania, Mitali; Kumar, Jay; Maier-Moore, Jacen S; Harris, Valerie M; Gopalakrishnan, Rajaram; Jonsson, Roland; Lessard, James A; Lu, Xianglan; Gottenberg, Jacques-Eric; Anaya, Juan-Manuel; Cunninghame-Graham, Deborah S; Huang, Andrew J W; Brennan, Michael T; Hughes, Pamela; Illei, Gabor G; Miceli-Richard, Corinne; Keystone, Edward C; Bykerk, Vivian P; Hirschfield, Gideon; Xie, Gang; Ng, Wan-Fai; Nordmark, Gunnel; Eriksson, Per; Omdal, Roald; Rhodus, Nelson L; Rischmueller, Maureen; Rohrer, Michael; Segal, Barbara M; Vyse, Timothy J; Wahren-Herlenius, Marie; Witte, Torsten; Pons-Estel, Bernardo; Alarcon-Riquelme, Marta E; Guthridge, Joel M; James, Judith A; Lessard, Christopher J; Kelly, Jennifer A; Thompson, Susan D; Gaffney, Patrick M; Montgomery, Courtney G; Edberg, Jeffrey C; Kimberly, Robert P; Alarcón, Graciela S; Langefeld, Carl L; Gilkeson, Gary S; Kamen, Diane L; Tsao, Betty P; McCune, W Joseph; Salmon, Jane E; Merrill, Joan T; Weisman, Michael H; Wallace, Daniel J; Utset, Tammy O; Bottinger, Erwin P; Amos, Christopher I; Siminovitch, Katherine A; Mariette, Xavier; Sivils, Kathy L; Harley, John B; Scofield, R Hal

    2016-05-01

    More than 80% of autoimmune disease predominantly affects females, but the mechanism for this female bias is poorly understood. We suspected that an X chromosome dose effect accounts for this, and we undertook this study to test our hypothesis that trisomy X (47,XXX; occurring in ∼1 in 1,000 live female births) would be increased in patients with female-predominant diseases (systemic lupus erythematosus [SLE], primary Sjögren's syndrome [SS], primary biliary cirrhosis, and rheumatoid arthritis [RA]) compared to patients with diseases without female predominance (sarcoidosis) and compared to controls. All subjects in this study were female. We identified subjects with 47,XXX using aggregate data from single-nucleotide polymorphism arrays, and, when possible, we confirmed the presence of 47,XXX using fluorescence in situ hybridization or quantitative polymerase chain reaction. We found 47,XXX in 7 of 2,826 SLE patients and in 3 of 1,033 SS patients, but in only 2 of 7,074 controls (odds ratio in the SLE and primary SS groups 8.78 [95% confidence interval 1.67-86.79], P = 0.003 and odds ratio 10.29 [95% confidence interval 1.18-123.47], P = 0.02, respectively). One in 404 women with SLE and 1 in 344 women with SS had 47,XXX. There was an excess of 47,XXX among SLE and SS patients. The estimated prevalence of SLE and SS in women with 47,XXX was ∼2.5 and ∼2.9 times higher, respectively, than that in women with 46,XX and ∼25 and ∼41 times higher, respectively, than that in men with 46,XY. No statistically significant increase of 47,XXX was observed in other female-biased diseases (primary biliary cirrhosis or RA), supporting the idea of multiple pathways to sex bias in autoimmunity. © 2016, American College of Rheumatology.

  6. X Chromosome Dose and Sex Bias in Autoimmune Diseases: Increased 47,XXX in Systemic Lupus Erythematosus and Sjögren’s Syndrome

    Science.gov (United States)

    Liu, Ke; Kurien, Biji T.; Zimmerman, Sarah L.; Kaufman, Kenneth M.; Taft, Diana H.; Kottyan, Leah C.; Lazaro, Sara; Weaver, Carrie A.; Ice, John A.; Adler, Adam J.; Chodosh, James; Radfar, Lida; Rasmussen, Astrid; Stone, Donald U.; Lewis, David M.; Li, Shibo; Koelsch, Kristi A.; Igoe, Ann; Talsania, Mitali; Kumar, Jay; Maier-Moore, Jacen S.; Harris, Valerie M.; Gopalakrishnan, Rajaram; Jonsson, Roland; Lessard, James A.; Lu, Xianglan; Gottenberg, Jacques-Eric; Anaya, Juan-Manuel; Cunninghame-Graham, Deborah S.; Huang, Andrew J. W.; Brennan, Michael T.; Hughes, Pamela; Illei, Gabor G.; Miceli-Richard, Corinne; Keystone, Edward C.; Bykerk, Vivian P.; Hirschfield, Gideon; Xie, Gang; Ng, Wan-Fai; Nordmark, Gunnel; Eriksson, Per; Omdal, Roald; Rhodus, Nelson L.; Rischmueller, Maureen; Rohrer, Michael; Segal, Barbara M.; Vyse, Timothy J.; Wahren-Herlenius, Marie; Witte, Torsten; Pons-Estel, Bernardo; Alarcon-Riquelme, Marta E.; Guthridge, Joel M.; James, Judith A.; Lessard, Christopher J.; Kelly, Jennifer A.; Thompson, Susan D.; Gaffney, Patrick M.; Montgomery, Courtney G.; Edberg, Jeffrey C; Kimberly, Robert P; Alarcón, Graciela S.; Langefeld, Carl L.; Gilkeson, Gary S.; Kamen, Diane L.; Tsao, Betty P.; McCune, W. Joseph; Salmon, Jane E.; Merrill, Joan T.; Weisman, Michael H; Wallace, Daniel J; Utset, Tammy O; Bottinger, Erwin P.; Amos, Christopher I.; Siminovitch, Katherine A.; Mariette, Xavier; Sivils, Kathy L.

    2016-01-01

    Objective More than 80% of autoimmune disease is female dominant, but the mechanism for this female bias is poorly understood. We suspected an X chromosome dose effect and hypothesized that trisomy X (47,XXX , 1 in ~1,000 live female births) would be increased in female predominant diseases (e.g. systemic lupus erythematosus [SLE], primary Sjögren’s syndrome [SS], primary biliary cirrhosis [PBC] and rheumatoid arthritis [RA]) compared to diseases without female predominance (sarcoidosis) and controls. Methods We identified 47,XXX subjects using aggregate data from single nucleotide polymorphism (SNP) arrays and confirmed, when possible, by fluorescent in situ hybridization (FISH) or quantitative polymerase chain reaction (q-PCR). Results We found 47,XXX in seven of 2,826 SLE and three of 1,033 SS female patients, but only in two of the 7,074 female controls (p=0.003, OR=8.78, 95% CI: 1.67-86.79 and p=0.02, OR=10.29, 95% CI: 1.18-123.47; respectively). One 47,XXX subject was present for ~404 SLE women and ~344 SS women. 47,XXX was present in excess among SLE and SS subjects. Conclusion The estimated prevalence of SLE and SS in women with 47,XXX was respectively ~2.5 and ~2.9 times higher than in 46,XX women and ~25 and ~41 times higher than in 46,XY men. No statistically significant increase of 47,XXX was observed in other female-biased diseases (PBC or RA), supporting the idea of multiple pathways to sex bias in autoimmunity. PMID:26713507

  7. Sex chromosomes and sex determination in Lepidoptera

    Czech Academy of Sciences Publication Activity Database

    Traut, W.; Sahara, K.; Marec, František

    1[2007], č. 6 (2008), s. 332-346 ISSN 1661-5425 R&D Projects: GA ČR GA206/06/1860 Institutional research plan: CEZ:AV0Z50070508 Keywords : balanced lethal * butterfly * evolution Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.000, year: 2008

  8. Distinctive metabolite profiles in in-migrating Sockeye salmon suggest sex-linked endocrine perturbation.

    Science.gov (United States)

    Benskin, Jonathan P; Ikonomou, Michael G; Liu, Jun; Veldhoen, Nik; Dubetz, Cory; Helbing, Caren C; Cosgrove, John R

    2014-10-07

    The health of Skeena River Sockeye salmon (Onchorhychus nerka) has been of increasing concern due to declining stock returns over the past decade. In the present work, in-migrating Sockeye from the 2008 run were evaluated using a mass spectrometry-based, targeted metabolomics platform. Our objectives were to (a) investigate natural changes in a subset of the hepatic metabolome arising from migration-associated changes in osmoregulation, locomotion, and gametogenesis, and (b) compare the resultant profiles with animals displaying altered hepatic vitellogenin A (vtg) expression at the spawning grounds, which was previously hypothesized as a marker of xenobiotic exposure. Of 203 metabolites monitored, 95 were consistently observed in Sockeye salmon livers and over half of these changed significantly during in-migration. Among the most dramatic changes in both sexes were a decrease in concentrations of taurine (a major organic osmolyte), carnitine (involved in fatty acid transport), and two major polyunsaturated fatty acids (eicosapentaenoic acid and docosahexaenoic acid). In females, an increase in amino acids was attributed to protein catabolism associated with vitellogenesis. Animals with atypical vtg mRNA expression demonstrated unusual hepatic amino acid, fatty acid, taurine, and carnitine profiles. The cause of these molecular perturbations remains unclear, but may include xenobiotic exposure, natural senescence, and/or interindividual variability. These data provide a benchmark for further investigation into the long-term health of migrating Skeena Sockeye.

  9. Identification of a distinct type IV collagen α chain with restricted kidney distribution and assignment of its gene to the locus of X chromosome-linked Alport syndrome

    International Nuclear Information System (INIS)

    Hostikka, S.L.; Hoeyhtyae, M.; Tryggvason, K.; Eddy, R.L.; Byers, M.G.; Shows, T.B.

    1990-01-01

    The authors have identified and extensively characterized a type IV collagen α chain, referred to as α5(IV). Four overlapping cDNA clones isolated contain an open reading frame for 543 amino acid residues of the carboxyl-terminal end of a collagenous domain, a 229-residue carboxyl-terminal noncollagenous domain, and 1201 base pairs coding for a 3' untranslated region. The collagenous Gly-Xaa-Yaa repeat sequence has five imperfections that coincide with those in the corresponding region of the α1(IV) chain. The noncollagenous domain has 12 conserved cysteine residues and 83% and 63% sequence identity with the noncollagenous domains of the α1(IV) and α2(IV) chains, respectively. The α5(IV) chain has less sequence identity with the putative bovine α3(IV) and α4(IV) chains. Antiserum against an α5(IV) synthetic peptide stained a polypeptide chain of about 185 kDa by immunoblot analysis and immunolocalization of the chain in human kidney was almost completely restricted to the glomerulus. The gene was assigned to the Xq22 locus by somatic cell hybrids and in situ hybridization. This may be identical or close to the locus of the X chromosome-linked Alport syndrome that is believed to be a type IV collagen disease

  10. Anticipated stigma and blameless guilt: Mothers' evaluation of life with the sex-linked disorder, hypohidrotic ectodermal dysplasia (XHED).

    Science.gov (United States)

    Clarke, Angus

    2016-06-01

    Practical experience of a genetic disorder may influence how parents approach reproduction, if they know their child may be affected by an inherited condition. One important aspect of this practical experience is the stigmatisation which family members may experience or witness. We outline the concept of stigma and how it affects those in families with a condition that impacts upon physical appearance. We then consider the accounts given by females in families affected by the rare sex-linked disorder, X-linked hypohidrotic ectodermal dysplasia (XHED), which principally affects males but can be passed through female carriers to affect their sons. The stigmatisation of affected males is as important in the accounts given by their womenfolk as the physical effects of the condition; this impacts on their talk about transmission of the disorder to the next generation. Perspectives may also change over time. The mothers of affected sons differ from their daughters, who do not yet have children, and from their mothers, who may express more strongly their sense of guilt at having transmitted the condition, despite there being no question of moral culpability. We conclude with suggestions about other contexts where the possibility of stigma may influence reproductive decisions. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  11. Quantitative sexing (Q-Sexing) and relative quantitative sexing (RQ ...

    African Journals Online (AJOL)

    samer

    Key words: Polymerase chain reaction (PCR), quantitative real time polymerase chain reaction (qPCR), quantitative sexing, Siberian tiger. INTRODUCTION. Animal molecular sexing .... 43:3-12. Ellegren H (1996). First gene on the avian W chromosome (CHD) provides a tag for universal sexing of non-ratite birds. Proc.

  12. Intrinsic Sex-Linked Variations in Osteogenic and Adipogenic Differentiation Potential of Bone Marrow Multipotent Stromal Cells.

    Science.gov (United States)

    Bragdon, Beth; Burns, Robert; Baker, Amelia H; Belkina, Anna C; Morgan, Elise F; Denis, Gerald V; Gerstenfeld, Louis C; Schlezinger, Jennifer J

    2015-02-01

    Bone formation and aging are sexually dimorphic. Yet, definition of the intrinsic molecular differences between male and female multipotent mesenchymal stromal cells (MSCs) in bone is lacking. This study assessed sex-linked differences in MSC differentiation in 3-, 6-, and 9-month-old C57BL/6J mice. Analysis of tibiae showed that female mice had lower bone volume fraction and higher adipocyte content in the bone marrow compared to age-matched males. While both males and females lost bone mass in early aging, the rate of loss was higher in males. Similar expression of bone- and adipocyte-related genes was seen in males and females at 3 and 9 months, while at 6 months, females exhibited a twofold greater expression of these genes. Under osteogenic culture conditions, bone marrow MSCs from female 3- and 6-month-old mice expressed similar levels of bone-related genes, but significantly greater levels of adipocyte-related genes, than male MSCs. Female MSCs also responded to rosiglitazone-induced suppression of osteogenesis at a 5-fold lower (10 nM) concentration than male MSCs. Female MSCs grown in estrogen-stripped medium showed similar responses to rosiglitazone as MSCs grown in serum containing estrogen. MSCs from female mice that had undergone ovariectomy before sexual maturity also were sensitive to rosiglitazone-induced effects on osteogenesis. These results suggest that female MSCs are more sensitive to modulation of differentiation by PPARγ and that these differences are intrinsic to the sex of the animal from which the MSCs came. These results also may explain the sensitivity of women to the deleterious effects of rosiglitazone on bone. © 2014 Wiley Periodicals, Inc.

  13. Destabilized SMC5/6 complex leads to chromosome breakage syndrome with severe lung disease

    NARCIS (Netherlands)

    van der Crabben, Saskia N; Hennus, Marije P; McGregor, Grant A; Ritter, Deborah I; Nagamani, Sandesh C S; Wells, Owen S; Harakalova, Magdalena; Chinn, Ivan K; Alt, Aaron; Vondrova, Lucie; Hochstenbach, Ron; van Montfrans, Joris M; Terheggen-Lagro, Suzanne W; van Lieshout, Stef; van Roosmalen, Markus J; Renkens, Ivo; Duran, Karen; Nijman, Isaäc J.; Kloosterman, Wigard P; Hennekam, Eric; Orange, Jordan S; van Hasselt, Peter M; Wheeler, David A; Palecek, Jan J; Lehmann, Alan R; Oliver, Antony W; Pearl, Laurence H; Plon, Sharon E; Murray, Johanne M; van Haaften, Gijs

    The structural maintenance of chromosomes (SMC) family of proteins supports mitotic proliferation, meiosis, and DNA repair to control genomic stability. Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. Here, we have identified a chromosome breakage syndrome

  14. Genetic method of combating the cabbage root fly. Part II. Localization of factor determining male sex in the cabbage root fly Delia brassicae bouche

    International Nuclear Information System (INIS)

    Samoilov, Yu.B.

    1986-01-01

    Cytogenetic analysis was conducted of 15 lines of the cabbage root fly with hereditary semisterility in the form of late embryonic lethals (LEL). In 14 lines (93%), the presence of translocations was noted. A high yield of translocations linked with the male sex was obtained, which was caused by the fact that determination of male sex in this species is apparently associated with the largest chromosome 6, and not with chromosome 1, as was believed previously

  15. Analysis of the sex-determining region of the Y chromosome (SRY) in sex reversed patients: point-mutation in SRY causing sex-reversion in a 46,XY female

    DEFF Research Database (Denmark)

    Müller, Jørn; Schwartz, M; Skakkebaek, N E

    1992-01-01

    The first and essential step in normal sexual differentiation takes place during the 5th-6th week of gestation. The testis determining factor (TDF) directs the undifferentiated gonad into a testis, which secretes hormones responsible for normal male development. A new candidate for TDF has recently...... been reported, and it has been called the sex determining region of the Y (SRY). The hypothesis has been supported by the finding of XX individuals with SRY, and two females with 46,XY karyotype and a mutation in SRY. However, XX males without SRY has been reported, and the role of SRY still has...... to be determined. We have tested three human females with 46,XY karyotype and gonadal dysgenesis and two 46,XX males for the presence of SRY using the polymerase chain reaction and subsequent DNA sequencing. Both 46,XX males contained SRY, whereas one of the 46,XY females had suffered a point mutation in SRY...

  16. Chromosome Y variants from different inbred mouse strains are linked to differences in the morphologic and molecular responses of cardiac cells to postpubertal testosterone

    Directory of Open Access Journals (Sweden)

    Churchill Gary A

    2009-04-01

    Full Text Available Abstract Background We have reported previously that when chromosome Y (chrY from the mouse strain C57BL/6J (ChrYC57 was substituted for that of A/J mice (ChrYA, cardiomyocytes from the resulting "chromosome substitution" C57BL/6J-chrYA strain were smaller than that of their C57BL/6J counterparts. In reverse, when chrYA from A/J mice was substituted for that of chrYC57, cardiomyocytes from the resulting A/J-chrYC57 strain were larger than in their A/J counterparts. We further used these strains to test whether: 1 the origin of chrY could also be linked to differences in the profile of gene expression in the hearts of adult male mice, and 2 post-pubertal testosterone could play a role in the differential morphologic and/or molecular effects of chrYC57 and chrYA. Results The increased size of cardiomyocytes from adult male C57BL/6J mice compared to C57BL/6J-chrYA resulted from the absence of hypertrophic effects of post-pubertal testosterone on cells from the latter strain. However, gene profiling revealed that the latter effect could not be explained on the basis of an insensitivity of cells from C57BL/6J-chrYA to androgens, since even more cardiac genes were affected by post-pubertal testosterone in C57BL/6J-chrYA hearts than in C57BL/6J. By testing for interaction between the effects of surgery and strain, we identified 249 "interaction genes" whose expression was affected by post-pubertal testosterone differentially according to the genetic origin of chrY. These interaction genes were found to be enriched within a limited number of signaling pathways, including: 1 p53 signaling, which comprises the interacting genes Ccnd1, Pten and Cdkn1a that are also potential co-regulators of the androgen receptors, and 2 circadian rhythm, which comprises Arntl/Bmal1, which may in turn regulate cell growth via the control of Cdkn1a. Conclusion Although post-pubertal testosterone increased the size of cardiomyocytes from male C56BL/6J mice but not that from

  17. The X chromosome in space.

    Science.gov (United States)

    Jégu, Teddy; Aeby, Eric; Lee, Jeannie T

    2017-06-01

    Extensive 3D folding is required to package a genome into the tiny nuclear space, and this packaging must be compatible with proper gene expression. Thus, in the well-hierarchized nucleus, chromosomes occupy discrete territories and adopt specific 3D organizational structures that facilitate interactions between regulatory elements for gene expression. The mammalian X chromosome exemplifies this structure-function relationship. Recent studies have shown that, upon X-chromosome inactivation, active and inactive X chromosomes localize to different subnuclear positions and adopt distinct chromosomal architectures that reflect their activity states. Here, we review the roles of long non-coding RNAs, chromosomal organizational structures and the subnuclear localization of chromosomes as they relate to X-linked gene expression.

  18. A model describing the effect of sex-reversed YY fish in an established wild population: The use of a Trojan Y chromosome to cause extinction of an introduced exotic species.

    Science.gov (United States)

    Gutierrez, Juan B; Teem, John L

    2006-07-21

    A novel means of inducing extinction of an exotic fish population is proposed using a genetic approach to shift the ratio of male to females within a population. In the proposed strategy, sex-reversed fish containing two Y chromosomes are introduced into a normal fish population. These YY fish result in the production of a disproportionate number of male fish in subsequent generations. Mathematical modeling of the system following introduction of YY fish at a constant rate reveals that female fish decline in numbers over time, leading to eventual extinction of the population.

  19. Tissue- and stage-dependent dosage compensation on the Neo-X chromosome in drosophila pseudoobscura

    KAUST Repository

    Nozawa, Masafumi

    2013-12-03

    Sex chromosome dosage compensation (DC) is widely accepted in various organisms. This concept is mostly supported by comparisons of gene expression between chromosomes and between sexes. However, genes on the X chromosome and autosomes are mostly not homologous, and the average gene expression level on these chromosomes may not be the same even under DC, which complicates comparisons between chromosomes. Many genes with sex-biased expression also make comparisons between sexes difficult. To overcome these issues, we investigated DC by comparing the expression of neo-X-linked genes in Drosophila pseudoobscura with those of their autosomal orthologs in other Drosophila species. The ratio of the former to the latter in males would be 1 under DC, whereas it becomes 0.5 without DC. We found that the ratio was ∼0.85 for adult whole bodies, indicating that the DC is incomplete on the neo-X chromosome in adults as a whole. The ratio (∼0.90) was also significantly less than 1 for adult bodies without gonads, whereas it was ∼1.0 for adult heads. These results indicate that DC varies among tissues. Our sliding-window analysis of the ratio also revealed that the upregulation of neo-X-linked genes in males occurred chromosome wide in all tissues analyzed, indicating global upregulation mechanisms. However, we found that gene functions also affected the levels of DC. Furthermore, most of the genes recently moved to the X were already under DC at the larval stage but not at the adult stage. These results suggest that DC in Drosophila species operates in a tissue/stage-dependent manner. © 2013 The Author 2013. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved.

  20. Guardian small RNAs and sex determination.

    Science.gov (United States)

    Katsuma, Susumu; Kawamoto, Munetaka; Kiuchi, Takashi

    2014-01-01

    The W chromosome of the silkworm Bombyx mori has been known to determine femaleness for more than 80 years. However, the feminizing gene has not been molecularly identified, because the B. mori W chromosome is almost fully occupied by a large number of transposable elements. The W chromosome-derived feminizing factor of B. mori was recently shown to be a female-specific PIWI-interacting RNA (piRNA). piRNAs are small RNAs that potentially repress invading "non-self" elements (e.g., transposons and virus-like elements) by associating with PIWI proteins. Our results revealed that female-specific piRNA precursors, which we named Fem, are transcribed from the sex-determining region of the W chromosome at the early embryonic stage and are processed into a single mature piRNA (Fem piRNA). Fem piRNA forms a complex with Siwi (silkworm Piwi), which cleaves a protein-coding mRNA transcribed from the Z chromosome. RNA interference of this Z-linked gene, which we named Masc, revealed that this gene encodes a protein required for masculinization and dosage compensation. Fem and Masc both participate in the ping-pong cycle of the piRNA amplification loop by associating with the 2 B. mori PIWI proteins Siwi and BmAgo3 (silkworm Ago3), respectively, indicating that the piRNA-mediated interaction between the 2 sex chromosomes is the primary signal for the B. mori sex determination cascade. Fem is a non-transposable repetitive sequence on the W chromosome, whereas Masc is a single-copy protein-coding gene. It is of great interest how the piRNA system recognizes "self "Masc mRNA as "non-self" RNA.

  1. Empirical evidence for son-killing X chromosomes and the operation of SA-zygotic drive.

    Directory of Open Access Journals (Sweden)

    Urban Friberg

    Full Text Available Diploid organisms have two copies of all genes, but only one is carried by each haploid gamete and diploid offspring. This causes a fundamental genetic conflict over transmission rate between alternative alleles. Single genes, or gene clusters, only rarely code for the complex phenotypes needed to give them a transmission advantage (drive phenotype. However, all genes on a male's X and Y chromosomes co-segregate, allowing different sex-linked genes to code for different parts of the drive phenotype. Correspondingly, the well-characterized phenomenon of male gametic drive, occurring during haploid gametogenesis, is especially common on sex chromosomes. The new theory of sexually antagonistic zygotic drive of the sex chromosomes (SA-zygotic drive extends the logic of gametic drive into the diploid phase of the lifecycle, whenever there is competition among siblings or harmful sib-sib mating. The X and Y are predicted to gain a transmission advantage by harming offspring of the sex that does not carry them.Here we analyzed a mutant X-chromosome in Drosophila simulans that produced an excess of daughters when transmitted from males. We developed a series of tests to differentiate between gametic and SA-zygotic drive, and provide multiple lines of evidence that SA-zygotic drive is responsible for the sex ratio bias. Driving sires produce about 50% more surviving daughters than sons.Sex-ratio distortion due to genetic conflict has evolved via gametic drive and maternally transmitted endosymbionts. Our data indicate that sex chromosomes can also drive by harming the non-carrier sex of offspring.

  2. Empirical evidence for son-killing X chromosomes and the operation of SA-zygotic drive.

    Science.gov (United States)

    Friberg, Urban; Stewart, Andrew D; Rice, William R

    2011-01-01

    Diploid organisms have two copies of all genes, but only one is carried by each haploid gamete and diploid offspring. This causes a fundamental genetic conflict over transmission rate between alternative alleles. Single genes, or gene clusters, only rarely code for the complex phenotypes needed to give them a transmission advantage (drive phenotype). However, all genes on a male's X and Y chromosomes co-segregate, allowing different sex-linked genes to code for different parts of the drive phenotype. Correspondingly, the well-characterized phenomenon of male gametic drive, occurring during haploid gametogenesis, is especially common on sex chromosomes. The new theory of sexually antagonistic zygotic drive of the sex chromosomes (SA-zygotic drive) extends the logic of gametic drive into the diploid phase of the lifecycle, whenever there is competition among siblings or harmful sib-sib mating. The X and Y are predicted to gain a transmission advantage by harming offspring of the sex that does not carry them. Here we analyzed a mutant X-chromosome in Drosophila simulans that produced an excess of daughters when transmitted from males. We developed a series of tests to differentiate between gametic and SA-zygotic drive, and provide multiple lines of evidence that SA-zygotic drive is responsible for the sex ratio bias. Driving sires produce about 50% more surviving daughters than sons. Sex-ratio distortion due to genetic conflict has evolved via gametic drive and maternally transmitted endosymbionts. Our data indicate that sex chromosomes can also drive by harming the non-carrier sex of offspring.

  3. Dosage compensation and demasculinization of X chromosomes in Drosophila.

    Science.gov (United States)

    Bachtrog, Doris; Toda, Nicholas R T; Lockton, Steven

    2010-08-24

    The X chromosome of Drosophila shows a deficiency of genes with male-biased expression, whereas mammalian X chromosomes are enriched for spermatogenesis genes expressed premeiosis and multicopy testis genes. Meiotic X-inactivation and sexual antagonism can only partly account for these patterns. Here, we show that dosage compensation (DC) in Drosophila may contribute substantially to the depletion of male genes on the X. To equalize expression between X-linked and autosomal genes in the two sexes, male Drosophila hypertranscribe their single X, whereas female mammals silence one of their two X chromosomes. We combine fine-scale mapping data of dosage compensated regions with genome-wide expression profiles and show that most male-biased genes on the D. melanogaster X are located outside dosage compensated regions. Additionally, X-linked genes that have newly acquired male-biased expression in D. melanogaster are less likely to be dosage compensated, and parental X-linked genes that gave rise to an autosomal male-biased retrocopy are more likely located within compensated regions. This suggests that DC contributes to the observed demasculinization of X chromosomes in Drosophila, both by limiting the emergence of male-biased expression patterns of existing X genes, and by contributing to gene trafficking of male genes off the X. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Aegilops tauschii Accessions with Geographically Diverse Origin Show Differences in Chromosome Organization and Polymorphism of Molecular Markers Linked to Leaf Rust and Powdery Mildew Resistance Genes.

    Science.gov (United States)

    Majka, Maciej; Kwiatek, Michał T; Majka, Joanna; Wiśniewska, Halina

    2017-01-01

    Aegilops tauschii (2n = 2x = 14) is a diploid wild species which is reported as a donor of the D-genome of cultivated bread wheat. The main goal of this study was to examine the differences and similarities in chromosomes organization among accessions of Ae. tauschii with geographically diversed origin, which is believed as a potential source of genes, especially determining resistance to fungal diseases (i.e., leaf rust and powdery mildew) for breeding of cereals. We established and compared the fluorescence in situ hybridization patterns of 21 accessions of Ae. tauschii using various repetitive sequences mainly from the BAC library of wheat cultivar Chinese Spring. Results obtained for Ae. tauschii chromosomes revealed many similarities between analyzed accessions, however, some hybridization patterns were specific for accessions, which become from cognate regions of the World. The most noticeable differences were observed for accessions from China which were characterized by presence of distinct signals of pTa-535 in the interstitial region of chromosome 3D, less intensity of pTa-86 signals in chromosome 2D, as well as lack of additional signals of pTa-86 in chromosomes 1D, 5D, or 6D. Ae. tauschii of Chinese origin appeared homogeneous and separate from landraces that originated in western Asia. Ae. tauschii chromosomes showed similar hybridization patterns to wheat D-genome chromosomes, but some differences were also observed among both species. What is more, we identified reciprocal translocation between short arm of chromosome 1D and long arm of chromosome 7D in accession with Iranian origin. High polymorphism between analyzed accessions and extensive allelic variation were revealed using molecular markers associated with resistance genes. Majority of the markers localized in chromosomes 1D and 2D showed the diversity of banding patterns between accessions. Obtained results imply, that there is a moderate or high level of polymorphism in the genome of Ae

  5. First report on an X-linked hypohidrotic ectodermal dysplasia family with X chromosome inversion: Breakpoint mapping reveals the pathogenic mechanism and preimplantation genetics diagnosis achieves an unaffected birth.

    Science.gov (United States)

    Wu, Tonghua; Yin, Biao; Zhu, Yuanchang; Li, Guangui; Ye, Lijun; Liang, Desheng; Zeng, Yong

    2017-12-01

    To investigate the etiology of X-linked hypohidrotic ectodermal dysplasia (XLHED) in a family with an inversion of the X chromosome [inv(X)(p21q13)] and to achieve a healthy birth following preimplantation genetic diagnosis (PGD). Next generation sequencing (NGS) and Sanger sequencing analysis were carried out to define the inversion breakpoint. Multiple displacement amplification, amplification of breakpoint junction fragments, Sanger sequencing of exon 1 of ED1, haplotyping of informative short tandem repeat markers and gender determination were performed for PGD. NGS data of the proband sample revealed that the size of the possible inverted fragment was over 42Mb, spanning from position 26, 814, 206 to position 69, 231, 915 on the X chromosome. The breakpoints were confirmed by Sanger sequencing. A total of 5 blastocyst embryos underwent trophectoderm biopsy. Two embryos were diagnosed as carriers and three were unaffected. Two unaffected blastocysts were transferred and a singleton pregnancy was achieved. Following confirmation by prenatal diagnosis, a healthy baby was delivered. This is the first report of an XLHED family with inv(X). ED1 is disrupted by the X chromosome inversion in this XLHED family and embryos with the X chromosomal abnormality can be accurately identified by means of PGD. Copyright © 2017. Published by Elsevier B.V.

  6. Know Your Chromosomes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 3. Know Your Chromosomes The Strong Holds of Family Trees. Vani Brahmachari. Series Article Volume 1 Issue 3 March 1996 pp 30-38. Fulltext. Click here to view fulltext PDF. Permanent link:

  7. Longitudinal characterization of two siblings with frontotemporal dementia and parkinsonism linked to chromosome 17 associated with the S305N tau mutation.

    Science.gov (United States)

    Boeve, Bradley F; Tremont-Lukats, Ivo W; Waclawik, Andrew J; Murrell, Jill R; Hermann, Bruce; Jack, Clifford R; Shiung, Maria M; Smith, Glenn E; Nair, Anil R; Lindor, Noralane; Koppikar, Vinaya; Ghetti, Bernardino

    2005-04-01

    The background to this study began with the reporting of two Japanese kindreds with the S305N tau mutation. Although the pathological findings in the autopsied cases were well characterized, only limited ante-mortem data were presented. In this study, longitudinal characterization was carried out in two siblings of European ancestry found to have frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) through comprehensive neurobehavioural examinations and other scales at approximate 6-month intervals. Scales included the Mini-Mental State Examination, Short Test of Mental Status, modified motor subtest of the Unified Parkinson's Disease Rating Scale, detailed neuropsychological testing, and the Neuropsychiatric Inventory. Changes in whole-brain volume and ventricular volume were measured from serial MRI studies. All members of the kindred underwent molecular genetic analyses to elucidate the mechanism of inheritance. The missense mutation in tau, S305N, was detected in the proband (onset age 30), who has undergone serial evaluations for almost 4 years. Her older sister (onset age 36) was subsequently found to have the same mutation, and has undergone serial evaluations for 2 years. This mutation is absent in both parents and the only other sibling, and non-paternity was excluded by additional analyses. The siblings have exhibited cognitive and behavioural features typical of FTDP-17, which have proved challenging to manage despite aggressive pharmacological and behavioural therapies. The proband's sister has demonstrated an atypical profile of impairment on neuropsychological testing. Both siblings have developed striking atrophy of the anterior part of temporal lobes and moderate atrophy of the dorsolateral and orbitofrontal cortical regions, which in both cases is relatively symmetrical. The annualized changes in whole-brain volume and ventricular volume, respectively, were -35.2 ml/year (3.23% decrease per year) and +20.75 ml/year (16

  8. A Comparison of Selective Pressures in Plant X-Linked and Autosomal Genes.

    Science.gov (United States)

    Krasovec, Marc; Nevado, Bruno; Filatov, Dmitry A

    2018-05-03

    Selection is expected to work differently in autosomal and X-linked genes because of their ploidy difference and the exposure of recessive X-linked mutations to haploid selection in males. However, it is not clear whether these expectations apply to recently evolved sex chromosomes, where many genes retain functional X- and Y-linked gametologs. We took advantage of the recently evolved sex chromosomes in the plant Silene latifolia and its closely related species to compare the selective pressures between hemizygous and non-hemizygous X-linked genes as well as between X-linked genes and autosomal genes. Our analysis, based on over 1000 genes, demonstrated that, similar to animals, X-linked genes in Silene evolve significantly faster than autosomal genes—the so-called faster-X effect. Contrary to expectations, faster-X divergence was detectable only for non-hemizygous X-linked genes. Our phylogeny-based analyses of selection revealed no evidence for faster adaptation in X-linked genes compared to autosomal genes. On the other hand, partial relaxation of purifying selection was apparent on the X-chromosome compared to the autosomes, consistent with a smaller genetic diversity in S. latifolia X-linked genes (π x = 0.016; π aut = 0.023). Thus, the faster-X divergence in S. latifolia appears to be a consequence of the smaller effective population size rather than of a faster adaptive evolution on the X-chromosome. We argue that this may be a general feature of “young” sex chromosomes, where the majority of X-linked genes are not hemizygous, preventing haploid selection in heterogametic sex.

  9. Accelerated pseudogenization on the neo-X chromosome in Drosophila miranda

    KAUST Repository

    Nozawa, Masafumi; Onizuka, Kanako; Fujimi, Mai; Ikeo, Kazuho; Gojobori, Takashi

    2016-01-01

    Y chromosomes often degenerate via the accumulation of pseudogenes and transposable elements. By contrast, little is known about X-chromosome degeneration. Here we compare the pseudogenization process between genes on the neo-sex chromosomes

  10. Modeling Chromosomes

    Science.gov (United States)

    Robertson, Carol

    2016-01-01

    Learning about chromosomes is standard fare in biology classrooms today. However, students may find it difficult to understand the relationships among the "genome", "chromosomes", "genes", a "gene locus", and "alleles". In the simple activity described in this article, which follows the 5E approach…

  11. Chromosomal Conditions

    Science.gov (United States)

    ... and more. Stony Point, NY 10980 Close X Home > Complications & Loss > Birth defects & other health conditions > Chromosomal conditions Chromosomal conditions ... Disorders See also: Genetic counseling , Your family health history Last reviewed: February, 2013 ... labor & premature birth The newborn intensive care unit (NICU) Birth defects & ...

  12. Divergent actions of long noncoding RNAs on X-chromosome ...

    Indian Academy of Sciences (India)

    2015-10-20

    Oct 20, 2015 ... Organisms with heterochromatic sex chromosomes need to compensate for differences in dosages of ... could also get genetically inactive and late replicating when ... tial to achieve the chromosomal level modifications were.

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

    Czech Academy of Sciences Publication Activity Database

    Pokorná, Martina; Kratochvíl, L.; Kejnovský, Eduard

    2011-01-01

    Roč. 12, č. 1 (2011), s. 90-96 ISSN 1471-2156 R&D Projects: GA ČR GAP506/10/0718; GA ČR(CZ) GAP305/10/0930 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50040702 Keywords : repeated dna-sequences * Y-chromosome * determining mechanisms Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.475, year: 2011

  14. Tracking the evolutionary pathway of sex chromosomes among fishes: characterizing the unique XX/XY1Y2 system in Hoplias malabaricus (Teleostei, Characiformes)

    Czech Academy of Sciences Publication Activity Database

    de Oliveira, E. A.; Sember, Alexandr; Bertollo, L.A.C.; Yano, C. F.; Ezaz, T.; Moreira-Filho, O.; Hatanaka, T.; Trifonov, V.; Liehr, T.; Al-Rikabi, A. B. H.; Ráb, Petr; Pains, H.; de Bello Cioffi, M.

    2018-01-01

    Roč. 127, č. 1 (2018), s. 115-128 ISSN 0009-5915 R&D Projects: GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : fish cytogenetics * male-specific region * whole chromosome painting Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 4.414, year: 2016

  15. An assessment of sex chromosome copy number in a phenotypic female patient with hypergonadtropic hypogonadism, primary amenorrhea and growth retardation by GTG-banding and FISH in peripheral blood and skin tissues

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, I.M.D.; DeMoranville, B.; Grollino, M.G. [Brown Univ. School of Medicine, Providence, RI (United States)] [and others

    1994-09-01

    The present report describes studies performed on an 18-year-old phenotypic female referred because of primary amenorrhea, hypergonadotropic hypoganadism and growth retardation. The clinical features raised the possibility of a gonadal dysgenesis. The ovaries were not identified on either side. Her testosterone was significantly elevated, with serum level at 48 ng/dl, and her free testosterone at 7 pg/ml. A GTG-banding analysis of 33 peripheral blood leukocytes revealed the modal number of chromosomes to be 46 per cell with a male sex constitution and normal appearing banding patterns (46,XY). In view of the clinical findings, additional cells were scored to rule out low percentage mosaicism. Out of 35 additional GTG-banded cells scored for the sex chromosomes, 4 cells (11.5%) were found to contain only one copy of the X chromosome. Fluorescent in situ hybridization (FISH) using dual color biotinylated X and Y probes (Imagenetics) was subsequently performed. Out of approximately 500 cells scored, 87% were found to be XY and 9% were found to be positive for the X signal only, versus 7% and 3% X signal only for 2 XY controls, aged 61 and 46, respectively. As loss of the Y chromosome has been reported in elderly males as well as certain males with leukemia, the age of the controls was important to note. To unequivocally establish the presence of mosaicism, a skin biopsy was obtained for fibroblast culture. Out of 388 total cells scored, 286 (74%) were found to be XY and 46 (12%) were found to be X, versus 99% XY and <1% X in controls. GTG-banding analysis of the same fibroblast culture is currently in progress. Preliminary data on this specimen thus far corroborate results of the FISH study. The presence of XY cells, along with an increased testosterone level, raises the distinct possibility of a gonadoblastoma. In view of this increased risk, arrangements are being made for the patient to have a laparoscopy and surgical removal of her presumptive streak gonads.

  16. Semi-automatic laser beam microdissection of the Y chromosome and analysis of Y chromosome DNA in a dioecious plant, Silene latifolia

    International Nuclear Information System (INIS)

    Matsunaga, S.; Kawano, S.; Michimoto, T.; Higashiyama, T.; Nakao, S.; Sakai, A.; Kuroiwa, T.

    1999-01-01

    Silene latifolia has heteromorphic sex chromosomes, the X and Y chromosomes. The Y chromosome, which is thought to carry the male determining gene, was isolated by UV laser microdissection and amplified by degenerate oligonucleotide-primed PCR. In situ chromosome suppression of the amplified Y chromosome DNA in the presence of female genomic DNA as a competitor showed that the microdissected Y chromosome DNA did not specifically hybridize to the Y chromosome, but-hybridized to all chromosomes. This result suggests that the Y chromosome does not contain Y chromosome-enriched repetitive sequences. A repetitive sequence in the microdissected Y chromosome, RMY1, was isolated while screening repetitive sequences in the amplified Y chromosome. Part of the nucleotide sequence shared a similarity to that of X-43.1, which was isolated from microdissected X chromosomes. Since fluorescence in situ hybridization analysis with RMY1 demonstrated that RMY1 was localized at the ends of the chromosome, RMY1 may be a subtelomeric repetitive sequence. Regarding the sex chromosomes, RMY1 was detected at both ends of the X chromosome and at one end near the pseudoautosomal region of the Y chromosome. The different localization of RMY1 on the sex chromosomes provides a clue to the problem of how the sex chromosomes arose from autosomes

  17. Mutagenic Potential of 4-Nitrophenyl Monochloromethyl (Phenyl) Phosphinate Using the Drosophila melanogaster Sex-Linked Recessive Lethal Test.

    Science.gov (United States)

    1983-08-01

    chromosomes were tested from the concurrent negative control. This sample size was adequate for analysis using the Fisher’s Exact test ( personal communication...study may be regarded as adequate ( personal communication - Dr. Gildengorin, Statistician, Information Sciences, Letterman Army Institute of Research...Health Sciences 0917 Arlington Road Bethesda MD 20014 CM nd Commander US Army Euvaoomens Hygine Agency US Army Research Institute Abardan Proving Ground MD

  18. Knockdown of μ-calpain in Fanconi Anemia, FA-A, cells by siRNA Restores αII Spectrin levels and Corrects Chromosomal Instability and Defective DNA Interstrand Cross-link Repair†

    OpenAIRE

    Zhang, Pan; Sridharan, Deepa; Lambert, Muriel W.

    2010-01-01

    We have previously shown that there is a deficiency in the structural protein, nonerythroid α spectrin (αIISp), in cells from patients with Fanconi anemia (FA). These studies indicate that this deficiency is due to reduced stability of αIISp and correlates with decreased repair of DNA interstrand cross-links and chromosomal instability in FA cells. An important factor in the stability of αIISp is its susceptibility to cleavage by the protease, μ-calpain. We hypothesized that increased μ-calpa...

  19. Chromosome Territories

    OpenAIRE

    Cremer, Thomas; Cremer, Marion

    2010-01-01

    Chromosome territories (CTs) constitute a major feature of nuclear architecture. In a brief statement, the possible contribution of nuclear architecture studies to the field of epigenomics is considered, followed by a historical account of the CT concept and the final compelling experimental evidence of a territorial organization of chromosomes in all eukaryotes studied to date. Present knowledge of nonrandom CT arrangements, of the internal CT architecture, and of structural interactions wit...

  20. Chromosomal aberration

    International Nuclear Information System (INIS)

    Ishii, Yutaka

    1988-01-01

    Chromosomal aberrations are classified into two types, chromosome-type and chromatid-type. Chromosom-type aberrations include terminal deletion, dicentric, ring and interstitial deletion, and chromatid-type aberrations include achromatic lesion, chromatid deletion, isochromatid deletion and chromatid exchange. Clastogens which induce chromosomal aberration are divided into ''S-dependent'' agents and ''S-independent''. It might mean whether they can induce double strand breaks independent of the S phase or not. Double strand breaks may be the ultimate lesions to induce chromosomal aberrations. Caffeine added even in the G 2 phase appeared to modify the frequency of chromatid aberrations induced by X-rays and mitomycin C. Those might suggest that the G 2 phase involves in the chromatid aberration formation. The double strand breaks might be repaired by ''G 2 repair system'', the error of which might yield breakage types of chromatid aberrations and the by-pass of which might yield chromatid exchanges. Chromosome-type aberrations might be formed in the G 1 phase. (author)

  1. Commentary Sex determination

    Indian Academy of Sciences (India)

    PRAKASH KUMAR G

    2008-01-31

    Jan 31, 2008 ... years old (Charnier 1966 reported it in an African agamid lizard), although it was ... people's attention in Susumu Ohno's now famous book on .... If they do enhance male and female fitness, sex chromosomes would then be.

  2. Substitution rates in the X- and Y-linked genes of the plants, Silene latifolia and S. dioica.

    Science.gov (United States)

    Filatov, Dmitry A; Charlesworth, Deborah

    2002-06-01

    Theory predicts that selection should be less effective in the nonrecombining genes of Y-chromosomes, relative to the situation for genes on the other chromosomes, and this should lead to the accumulation of deleterious nonsynonymous substitutions. In addition, synonymous substitution rates may differ between X- and Y-linked genes because of the male-driven evolution effect and also because of actual differences in per-replication mutation rates between the sex chromosomes. Here, we report the first study of synonymous and nonsynonymous substitution rates on plant sex chromosomes. We sequenced two pairs of sex-linked genes, SlX1-SlY1 and SlX4-SlY4, from dioecious Silene latifolia and S. dioica, and their non-sex-linked homologues from nondioecious S. vulgaris and Lychnis flos-jovis, respectively. The rate of nonsynonymous substitutions in the SlY4 gene is significantly higher than that in the SlX4 gene. Silent substitution rates are also significantly higher in both Y-linked genes, compared with their X-linked homologues. The higher nonsynonymous substitution rate in the SlY4 gene is therefore likely to be caused by a mutation rate difference between the sex chromosomes. The difference in silent substitution rates between the SlX4 and SlY4 genes is too great to be explained solely by a higher per-generation mutation rate in males than females. It is thus probably caused by a difference in per-replication mutation rates between the sex chromosomes. This suggests that the local mutation rate can change in a relatively short evolutionary time.

  3. ECOLOGICAL AND EVOLUTIONARY APPLICATIONS FOR ENVIRONMENTAL SEX REVERSAL OF FISH.

    Science.gov (United States)

    Mcnair, Alistair; Lokman, P Mark; Closs, Gerard P; Nakagawa, Shinichi

    2015-03-01

    Environmental sex reversal (ESR), which results in a mismatch between genotypic and phenotypic sex, is well documented in numerous fish species and may be induced by chemical exposure. Historically, research involving piscine ESR has been carried out with a view to improving profitability in aquaculture or to elucidate the processes governing sex determination and sexual differentiation. However, recent studies in evolution and ecology suggest research on ESR now has much wider applications and ramifications. We begin with an overview of ESR in fish and a brief review of the traditional applications thereof. We then discuss ESR and its potential demographic consequences in wild populations. Theory even suggests sex-reversed fish may be purposefully released to manipulate population dynamics. We suggest new research directions that may prove fruitful in understanding how ESR at the individual level translates to population-level processes. In the latter portion of the review we focus on evolutionary applications of ESR. Sex-reversal studies from the aquaculture literature provide insight in to the evolvability of determinants of sexual phenotype. Additionally, induced sex reversal can provide information about the evolution of sex chromosomes and sex-linked traits. Recently, naturally occurring ESR has been implicated as a mechanism contributing to the evolution of sex chromosomes.

  4. Linking the Y-chromosomal haplotype from a high medieval (1160-1421) skeleton from a Podlazice excavation site with living descendants

    Czech Academy of Sciences Publication Activity Database

    Votrubová, J.; Sasková, L.; Frolík, Jan; Vaněk, D.

    2017-01-01

    Roč. 6, December (2017), „e129”-„e131” ISSN 1875-1768 R&D Projects: GA ČR GB14-36938G Institutional support: RVO:67985912 Keywords : Y chromosome haplotype * surname * inheritance * forensics * bone * bioarchaeology * genetics of cemeteries Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology http://www.fsigeneticssup.com/article/S1875-1768(17)30160-9/pdf

  5. Contrasting Patterns of Transposable Element and Satellite Distribution on Sex Chromosomes (XY1Y2) in the Dioecious Plant Rumex acetosa

    Czech Academy of Sciences Publication Activity Database

    Šteflová, Pavlína; Tokan, Viktor; Vogel, Ivan; Lexa, M.; Macas, Jiří; Novák, Petr; Hobza, Roman; Vyskot, Boris; Kejnovský, Eduard

    2013-01-01

    Roč. 5, č. 4 (2013), s. 769-782 ISSN 1759-6653 R&D Projects: GA ČR(CZ) GAP305/10/0930; GA ČR(CZ) GAP501/10/0102; GA ČR(CZ) GAP501/12/2220 Grant - others:GA MŠk(CZ) ED1.1.00/02.0068 Program:ED Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 ; RVO:60077344 Keywords : Y-CHROMOSOME * REPETITIVE SEQUENCES * SILENE-LATIFOLIA Subject RIV: BO - Biophysics; EB - Genetics ; Molecular Biology (BC-A) Impact factor: 4.532, year: 2013

  6. Baseline frequency of chromosomal aberrations and sister chromatid exchanges in peripheral blood lymphocytes of healthy individuals living in Turin (North-Western Italy): assessment of the effects of age, sex and GSTs gene polymorphisms on the levels of genomic damage.

    Science.gov (United States)

    Santovito, Alfredo; Cervella, Piero; Delpero, Massimiliano

    2016-05-01

    The increased exposure to environmental pollutants has led to the awareness of the necessity for constant monitoring of human populations, especially those living in urban areas. This study evaluated the background levels of genomic damage in a sample of healthy subjects living in the urban area of Turin (Italy). The association between DNA damage with age, sex and GSTs polymorphisms was assessed. One hundred and one individuals were randomly sampled. Sister Chromatid Exchanges (SCEs) and Chromosomal Aberrations (CAs) assays, as well as genotyping of GSTT1 and GSTM1 genes, were performed. Mean values of SCEs and CAs were 5.137 ± 0.166 and 0.018 ± 0.002, respectively. Results showed age and gender associated with higher frequencies of these two cytogenetic markers. The eldest subjects (51-65 years) showed significantly higher levels of genomic damage than younger individuals. GSTs polymorphisms did not appear to significantly influence the frequencies of either markers. The CAs background frequency observed in this study is one of the highest reported among European populations. Turin is one of the most polluted cities in Europe in terms of air fine PM10 and ozone and the clastogenic potential of these pollutants may explain the high frequencies of chromosomal rearrangements reported here.

  7. Effects of a chromosome-3 mutator gene on radiation-induced mutability in Drosophila melanogaster females

    Energy Technology Data Exchange (ETDEWEB)

    Sankaranarayanan, K. (Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Cohen (J.A.) Inst. voor Radiopathologie en Stralenbescherming, Leiden (Netherlands))

    1982-01-01

    A series of X-irradiation experiments was carried out using Drosophila melanogaster females homozygous for a third chromosome mutator gene and females which had a similar genetic background except that the mutator-bearing third chromosomes were substituted by normal wild-type chromosomes. In the present work, the sensitivity of the pre-meiotic germ cells of mutator and normal females to the X-ray induction (2000 R) of sex-linked recessive lethals was studied. In addition, experiments were conducted to examine the sensitivity of the immature (stage 7; prophase I of meiosis) oocytes of both kinds of females to the induction of dominant lethals, X-linked recessive lethals and X-chromosome losses. The results show that in pre-meiotic germ cells, the frequencies of radiation-induced recessive lethals are similar in both kinds of females. However, the proportion of these mutations that occur in clusters of size 3 and higher, is higher in mutator than in normal females. In stage-7 oocytes, the frequencies of radiation-induced dominant lethals and sex-linked recessive lethals were similar in both kinds of females. The X-loss frequencies however, were consistently higher in mutator females although statistical significance was obtained only at higher exposures (3000 and 3750 R) and not at lower ones (750-2250 R). Possible reasons for the discrepancy between the present results and those of Gold and Green with respect to pre-meiotic germ cells are discussed.

  8. Succumbing to the Call of Violence – Sex-Linked Development of Appetitive Aggression in Relation to Familial and Organized Violence

    Directory of Open Access Journals (Sweden)

    Mareike Augsburger

    2017-05-01

    Full Text Available Appetitive aggression is the attraction to violent behavior, which can peak in the experience of a combat high. In various war and conflict scenarios, members of armed groups have reported developing a desire to hunt and even kill humans. More recently, we reported that the phenomenon has also been observed in female ex-combatants with varying participation in warfare. Despite recent investigations on risk factors for appetitive aggression, sex-specific pathways in the development of appetitive aggression have not yet been delineated. This study investigated moderation effects of sex on previously identified risk factors for appetitive aggression by means of regression analyses in a sample of individuals with varying degrees of warfare participation (overall sample, n = 602. First examining a sample characterized by backgrounds heterogeneous in both sociodemographic data and war experiences, the analysis was then replicated in a subsample of fighters active during the civil war (combatant sample, n = 109. In both samples, regression analyses revealed significant moderation effects of sex. Childhood maltreatment and traumatic events had positive associations on the development of appetitive aggression for males but a negative (childhood maltreatment or no (traumatic events association for females. Perpetrated events were more strongly correlated with appetitive aggression for females than for males. This pattern was pronounced for the combatant sample. These results are in favor of sex-linked pathways. In both sexes, appetitive aggression may have evolved as a biologically prepared response to cruel environments but might develop along different trajectories. The current study highlights the need for addressing appetitive aggression in order to support peace-building processes and emphasizes sex specific starting-points.

  9. Sex-specific effects on spatial learning and memory, and sex-independent effects on blood pressure of a <3.3 Mbp rat chromosome 2 QTL region in Dahl salt-sensitive rats.

    Directory of Open Access Journals (Sweden)

    Victoria L Herrera

    Full Text Available Epidemiological studies have consistently found that hypertension is associated with poor cognitive performance. We hypothesize that a putative causal mechanism underlying this association is due to genetic loci affecting both blood pressure and cognition. Consistent with this notion, we reported several blood pressure (BP quantitative trait loci (QTLs that co-localized with navigational performance (Nav-QTLs influencing spatial learning and memory in Dahl rats. The present study investigates a chromosome 2 region harboring BP-f4 and Nav-8 QTLs. We developed two congenic strains, S.R2A and S.R2B introgressing Dahl R-chromosome 2 segments into Dahl S chromosome 2 region spanning BP-f4 and Nav-8 QTLs. Radiotelemetric blood pressure analysis identified only S.R2A congenic rats with lower systolic blood pressure (females: -26.0 mmHg, P = 0.003; males: -30.9 mmHg, P<1×10(-5, diastolic blood pressure (females: -21.2 mmHg, P = 0.01; males: -25.7 mmHg, P<1×10(-5, and mean arterial pressure (females: -23.9 mmHg, P = 0.004; males: -28.0 mmHg, P<1×10(-5 compared with corresponding Dahl S controls, confirming the presence of BP-f4 QTL on rat chromosome 2. The S.R2B congenic segment did not affect blood pressure. Testing of S.R2A, S.R2B, and Dahl S male rats in the Morris water maze (MWM task revealed significantly decreased spatial navigation performance in S.R2A male congenic rats when compared with Dahl S male controls (P<0.05. The S.R2B congenic segment did not affect performance of the MWM task in males. The S.R2A female rats did not differ in spatial navigation when compared with Dahl S female controls, indicating that the Nav-8 effect on spatial navigation is male-specific. Our results suggest the existence of a single QTL on chromosome 2 176.6-179.9 Mbp region which affects blood pressure in both males and females and cognition solely in males.

  10. Sex-specific effects on spatial learning and memory, and sex-independent effects on blood pressure of a <3.3 Mbp rat chromosome 2 QTL region in Dahl salt-sensitive rats.

    Science.gov (United States)

    Herrera, Victoria L; Pasion, Khristine A; Tan, Glaiza A; Moran, Ann Marie; Ruiz-Opazo, Nelson

    2013-01-01

    Epidemiological studies have consistently found that hypertension is associated with poor cognitive performance. We hypothesize that a putative causal mechanism underlying this association is due to genetic loci affecting both blood pressure and cognition. Consistent with this notion, we reported several blood pressure (BP) quantitative trait loci (QTLs) that co-localized with navigational performance (Nav)-QTLs influencing spatial learning and memory in Dahl rats. The present study investigates a chromosome 2 region harboring BP-f4 and Nav-8 QTLs. We developed two congenic strains, S.R2A and S.R2B introgressing Dahl R-chromosome 2 segments into Dahl S chromosome 2 region spanning BP-f4 and Nav-8 QTLs. Radiotelemetric blood pressure analysis identified only S.R2A congenic rats with lower systolic blood pressure (females: -26.0 mmHg, P = 0.003; males: -30.9 mmHg, P<1×10(-5)), diastolic blood pressure (females: -21.2 mmHg, P = 0.01; males: -25.7 mmHg, P<1×10(-5)), and mean arterial pressure (females: -23.9 mmHg, P = 0.004; males: -28.0 mmHg, P<1×10(-5)) compared with corresponding Dahl S controls, confirming the presence of BP-f4 QTL on rat chromosome 2. The S.R2B congenic segment did not affect blood pressure. Testing of S.R2A, S.R2B, and Dahl S male rats in the Morris water maze (MWM) task revealed significantly decreased spatial navigation performance in S.R2A male congenic rats when compared with Dahl S male controls (P<0.05). The S.R2B congenic segment did not affect performance of the MWM task in males. The S.R2A female rats did not differ in spatial navigation when compared with Dahl S female controls, indicating that the Nav-8 effect on spatial navigation is male-specific. Our results suggest the existence of a single QTL on chromosome 2 176.6-179.9 Mbp region which affects blood pressure in both males and females and cognition solely in males.

  11. Sex. Dev.

    OpenAIRE

    Jakubiczka, S.; Schröder, C.; Ullmann, R.; Volleth, M.; Ledig, S.; Gilberg, E.; Kroisel, P.; P. Wieacker, P.

    2010-01-01

    Campomelic dysplasia (MIM 114290) is a severe malformation syndrome frequently accompanied by male-to-female sex reversal. Causative are mutations within the SOX9 gene on 17q24.3 as well as chromosomal aberrations (translocations, inversions or deletions) in the vicinity of SOX9 . Here, we report on a patient with muscular hypotonia, craniofacial dysmorphism, cleft palate, brachydactyly, malformations of thoracic spine, and gonadal dysgenesis with female external genitalia and müllerian duct ...

  12. Investigating stakeholders' perceptions of the link between high STD rates and the current Baltimore City Public Schools' sex education curriculum

    Science.gov (United States)

    Bolden, Shenell L. T.

    The purpose of this exploratory study was to examine key stakeholders' perceptions of the current Baltimore City Public Schools' (BCPS) sex education curriculum and to gain insight into how they believe the curriculum could be modified to be more effective. A mixed methods approach using qualitative and quantitative data collection consisting of a survey, focus group interview, and individual interviews was conducted to gather information on stakeholders' perceptions. The stakeholders included: (1) former students who received their sex education courses in the Baltimore City Public School system (BCPS); (2) teachers in BCPS who were affiliated with the sex education curriculum; (3) health care professionals who screened and/or treated East Baltimore City residents for a sexually transmitted disease (STD) and; (4) one policy maker who was responsible for creating sex education curriculum at the national level. Analysis of the quantitative data from former Baltimore City Public School students revealed a general satisfaction with the current sex education curriculum. However, qualitative data from the same group of stakeholders revealed several changes they thought should be implemented into the program in an effort to improve the current curriculum. Findings from the other groups after qualitative analysis of the interviews suggest three major themes in support of curriculum change: (1) a blended curriculum that integrates both the cognitive and affective learning domains; (2) knowledge of prevention of STD's and pregnancy; and (3) authentic teaching and learning. Results from this study strongly suggest that the Baltimore City Public School system is apathetic to the sexual health needs of students and, therefore, is inadvertently contributing to the high rate of sexually transmitted diseases among young people. Keywords: Abstinence, Affective domain, Indoctrination, Behavior Modification, Cognitive domain, Sex education curriculum, Sexually Transmitted Diseases.

  13. Linking sex differences in corticosterone with individual reproductive behaviour and hatch success in two species of uniparental shorebirds.

    Science.gov (United States)

    Edwards, Darryl B; Chin, Eunice H; Burness, Gary; Gilchrist, H Grant; Schulte-Hostedde, Albrecht I

    2013-09-01

    In birds, corticosterone (CORT) appears to facilitate reproductive activity because baseline and stress-induced CORT levels are elevated in breeding individuals compared with other times of the year. In particular, CORT is lower in the sex providing most of the parental care (i.e., incubation), which could be an important adaptation to tolerate stressors that result in abandoning reproduction. Therefore, one explanation for sex differences in CORT is that lower levels are favoured during the incubation/parental phase of reproduction. Using two species of uniparental shorebird - polyandrous red phalaropes (Phalaropus fulicarius) and polygynous white-rumped sandpipers (Calidris fuscicollis) - we predicted that the incubating sex would have lower baseline and stress-induced CORT, and incubating individuals with lower CORT would more effectively defend nests against a simulated intrusion, would return more quickly afterwards, and would ultimately have higher hatch success. We found that phalaropes followed the predicted pattern: incubating individuals (males) had lower baseline and stress-induced CORT than females but for baseline CORT these differences existed prior to males commencing incubation. Incubating male phalaropes with lower baseline and stress-induced CORT returned to incubate more quickly after a disturbance and there was non-significant tendency for baseline CORT to be lower in successful nests. In sandpipers, we observed no sex differences and no significant relationships between individual CORT levels and nest defence behaviours or hatch success. Our results demonstrate that in phalaropes at least, selection favours lower baseline and stress-induced CORT during the nesting period. These results can explain sex differences in stress-induced levels of CORT, however sex differences in baseline CORT were present prior to incubation. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Statistics for X-chromosome associations.

    Science.gov (United States)

    Özbek, Umut; Lin, Hui-Min; Lin, Yan; Weeks, Daniel E; Chen, Wei; Shaffer, John R; Purcell, Shaun M; Feingold, Eleanor

    2018-06-13

    In a genome-wide association study (GWAS), association between genotype and phenotype at autosomal loci is generally tested by regression models. However, X-chromosome data are often excluded from published analyses of autosomes because of the difference between males and females in number of X chromosomes. Failure to analyze X-chromosome data at all is obviously less than ideal, and can lead to missed discoveries. Even when X-chromosome data are included, they are often analyzed with suboptimal statistics. Several mathematically sensible statistics for X-chromosome association have been proposed. The optimality of these statistics, however, is based on very specific simple genetic models. In addition, while previous simulation studies of these statistics have been informative, they have focused on single-marker tests and have not considered the types of error that occur even under the null hypothesis when the entire X chromosome is scanned. In this study, we comprehensively tested several X-chromosome association statistics using simulation studies that include the entire chromosome. We also considered a wide range of trait models for sex differences and phenotypic effects of X inactivation. We found that models that do not incorporate a sex effect can have large type I error in some cases. We also found that many of the best statistics perform well even when there are modest deviations, such as trait variance differences between the sexes or small sex differences in allele frequencies, from assumptions. © 2018 WILEY PERIODICALS, INC.

  15. Chromosome analysis of arsenic affected cattle

    Directory of Open Access Journals (Sweden)

    S. Shekhar

    2014-10-01

    Full Text Available Aim: The aim was to study the chromosome analysis of arsenic affected cattle. Materials and Methods: 27 female cattle (21 arsenic affected and 6 normal were selected for cytogenetical study. The blood samples were collected, incubated, and cultured using appropriate media and specific methods. The samples were analyzed for chromosome number and morphology, relative length of the chromosome, arm ratio, and centromere index of X chromosome and chromosomal abnormalities in arsenic affected cattle to that of normal ones. Results: The diploid number of metaphase chromosomes in arsenic affected cattle as well as in normal cattle were all 2n=60, 58 being autosomes and 2 being sex chromosomes. From the centromeric position, karyotyping studies revealed that all the 29 pair of autosomes was found to be acrocentric or telocentric, and the sex chromosomes (XX were submetacentric in both normal and arsenic affected cattle. The relative length of all the autosome pairs and sex chrosomosome pair was found to be higher in normal than that of arsenic affected cattle. The mean arm ratio of X-chromosome was higher in normal than that of arsenic affected cattle, but it is reverse in case of centromere index value of X-chromosome. There was no significant difference of arm ratio and centromere index of X-chromosomes between arsenic affected and normal cattle. No chromosomal abnormalities were found in arsenic affected cattle. Conclusion: The chromosome analysis of arsenic affected cattle in West Bengal reported for the first time in this present study which may serve as a guideline for future studies in other species. These reference values will also help in comparison of cytological studies of arsenic affected cattle to that of various toxicants.

  16. X-Chromosome Control of Genome-Scale Recombination Rates in House Mice.

    Science.gov (United States)

    Dumont, Beth L

    2017-04-01

    Sex differences in recombination are widespread in mammals, but the causes of this pattern are poorly understood. Previously, males from two interfertile subspecies of house mice, Mus musculus musculus and M. m. castaneus , were shown to exhibit a ∼30% difference in their global crossover frequencies. Much of this crossover rate divergence is explained by six autosomal loci and a large-effect locus on the X chromosome. Intriguingly, the allelic effects at this X-linked locus are transgressive, with the allele conferring increased crossover rate being transmitted by the low crossover rate M. m. castaneus parent. Despite the pronounced divergence between males, females from these subspecies exhibit similar crossover rates, raising the question of how recombination is genetically controlled in this sex. Here, I analyze publicly available genotype data from early generations of the Collaborative Cross, an eight-way panel of recombinant inbred strains, to estimate crossover frequencies in female mice with sex-chromosome genotypes of diverse subspecific origins. Consistent with the transgressive influence of the X chromosome in males, I show that females inheriting an M. m. castaneus X possess higher average crossover rates than females lacking the M. m. castaneus X chromosome. The differential inheritance of the X chromosome in males and females provides a simple genetic explanation for sex-limited evolution of this trait. Further, the presence of X-linked and autosomal crossover rate modifiers with antagonistic effects hints at an underlying genetic conflict fueled by selection for distinct crossover rate optima in males and females. Copyright © 2017 by the Genetics Society of America.

  17. Observation of a ZZW female in a natural population: implications for avian sex determination.

    Science.gov (United States)

    Arit, D; Bensch, S; Hansson, B; Hasselquist, D; Westerdahl, H

    2004-01-01

    Avian sex determination is chromosomal; however, the underlying mechanisms are not yet understood. There is no conclusive evidence for either of two proposed mechanisms: a dominant genetic switch or a dosage mechanism. No dominant sex-determining gene on the female-specific W chromosome has been found. Birds lack inactivation of one of the Z chromosomes in males, but seem to compensate for a double dose of Z-linked genes by other mechanisms. Recent studies showing female-specific expression of two genes may support an active role of the W chromosome. To resolve the question of avian sex determination the investigation of birds with a 2A: ZZW or 2A: ZO genotype would be decisive. Here, we report the case of an apparent 2A: ZZW great reed warbler (Acrocephalus arundinaceus) female breeding in a natural population, which was detected using Z-linked microsatellites. Our data strongly suggest a role of W-linked genes in avian sex determination. PMID:15252998

  18. Plasminogen activator inhibitor type 1 gene is located at region q21.3-q22 of chromosome 7 and genetically linked with cystic fibrosis

    International Nuclear Information System (INIS)

    Klinger, K.W.; Winqvist, R.; Riccio, A.

    1987-01-01

    The regional chromosomal location of the human gene for plasminogen activator inhibitor type 1 (PAI1) was determined by three independent methods of gene mapping. PAI1 was localized first to 7cen-q32 and then to 7q21.3-q22 by Southern blot hybridization analysis of a panel of human and mouse somatic cell hybrids with a PAI1 cDNA probe and in situ hybridization, respectively. The authors frequent HindIII restriction fragment length polymorphism (RFLP) of the PAI1 gene with an information content of 0.369. In family studies using this polymorphism, genetic linkage was found between PAI1 and the loci for erythropoietin (EPO), paraoxonase (PON), the met protooncogene (MET), and cystic fibrosis (CF), all previously assigned to the middle part of the long arm of chromosome 7. The linkage with EPO was closest with an estimated genetic distance of 3 centimorgans, whereas that to CF was 20 centimorgans. A three-point genetic linkage analysis and data from previous studies showed that the most likely order of these loci is EPO, PAI1, PON, (MET, CF), with PAI1 being located centromeric to CF. The PAI1 RFLP may prove to be valuable in ordering genetic markers in the CF-linkage group and may also be valuable in genetic analysis of plasminogen activation-related diseases, such as certain thromboembolic disorders and cancer

  19. Sex Reversal in Birds.

    Science.gov (United States)

    Major, Andrew T; Smith, Craig A

    2016-01-01

    Sexual differentiation in birds is controlled genetically as in mammals, although the sex chromosomes are different. Males have a ZZ sex chromosome constitution, while females are ZW. Gene(s) on the sex chromosomes must initiate gonadal sex differentiation during embryonic life, inducing paired testes in ZZ individuals and unilateral ovaries in ZW individuals. The traditional view of avian sexual differentiation aligns with that expounded for other vertebrates; upon sexual differentiation, the gonads secrete sex steroid hormones that masculinise or feminise the rest of the body. However, recent studies on naturally occurring or experimentally induced avian sex reversal suggest a significant role for direct genetic factors, in addition to sex hormones, in regulating sexual differentiation of the soma in birds. This review will provide an overview of sex determination in birds and both naturally and experimentally induced sex reversal, with emphasis on the key role of oestrogen. We then consider how recent studies on sex reversal and gynandromorphic birds (half male:half female) are shaping our understanding of sexual differentiation in avians and in vertebrates more broadly. Current evidence shows that sexual differentiation in birds is a mix of direct genetic and hormonal mechanisms. Perturbation of either of these components may lead to sex reversal. © 2016 S. Karger AG, Basel.

  20. Sex linkage, sex-specific selection, and the role of recombination in the evolution of sexually dimorphic gene expression.

    Science.gov (United States)

    Connallon, Tim; Clark, Andrew G

    2010-12-01

    Sex-biased genes--genes that are differentially expressed within males and females--are nonrandomly distributed across animal genomes, with sex chromosomes and autosomes often carrying markedly different concentrations of male- and female-biased genes. These linkage patterns are often gene- and lineage-dependent, differing between functional genetic categories and between species. Although sex-specific selection is often hypothesized to shape the evolution of sex-linked and autosomal gene content, population genetics theory has yet to account for many of the gene- and lineage-specific idiosyncrasies emerging from the empirical literature. With the goal of improving the connection between evolutionary theory and a rapidly growing body of genome-wide empirical studies, we extend previous population genetics theory of sex-specific selection by developing and analyzing a biologically informed model that incorporates sex linkage, pleiotropy, recombination, and epistasis, factors that are likely to vary between genes and between species. Our results demonstrate that sex-specific selection and sex-specific recombination rates can generate, and are compatible with, the gene- and species-specific linkage patterns reported in the genomics literature. The theory suggests that sexual selection may strongly influence the architectures of animal genomes, as well as the chromosomal distribution of fixed substitutions underlying sexually dimorphic traits. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  1. Evolutionary Dynamics of the Gametologous CTNNB1 Gene on the Z and W Chromosomes of Snakes.

    Science.gov (United States)

    Laopichienpong, Nararat; Muangmai, Narongrit; Chanhome, Lawan; Suntrarachun, Sunutcha; Twilprawat, Panupon; Peyachoknagul, Surin; Srikulnath, Kornsorn

    2017-03-01

    Snakes exhibit genotypic sex determination with female heterogamety (ZZ males and ZW females), and the state of sex chromosome differentiation also varies among lineages. To investigate the evolutionary history of homologous genes located in the nonrecombining region of differentiated sex chromosomes in snakes, partial sequences of the gametologous CTNNB1 gene were analyzed for 12 species belonging to henophid (Cylindrophiidae, Xenopeltidae, and Pythonidae) and caenophid snakes (Viperidae, Elapidae, and Colubridae). Nonsynonymous/synonymous substitution ratios (Ka/Ks) in coding sequences were low (Ka/Ks < 1) between CTNNB1Z and CTNNB1W, suggesting that these 2 genes may have similar functional properties. However, frequencies of intron sequence substitutions and insertion–deletions were higher in CTNNB1Z than CTNNB1W, suggesting that Z-linked sequences evolved faster than W-linked sequences. Molecular phylogeny based on both intron and exon sequences showed the presence of 2 major clades: 1) Z-linked sequences of Caenophidia and 2) W-linked sequences of Caenophidia clustered with Z-linked sequences of Henophidia, which suggests that the sequence divergence between CTNNB1Z and CTNNB1W in Caenophidia may have occurred by the cessation of recombination after the split from Henophidia.

  2. The impact of childhood abuse on inpatient substance users: specific links with risky sex, aggression, and emotion dysregulation.

    Science.gov (United States)

    Banducci, Anne N; Hoffman, Elana M; Lejuez, C W; Koenen, Karestan C

    2014-05-01

    Adults with substance use disorders (SUDs) report a high prevalence of childhood abuse. Research in the general population suggests specific types of abuse lead to particular negative outcomes; it is not known whether this pattern holds for adults with SUDs. We hypothesized that specific types of abuse would be associated with particular behavioral and emotional outcomes among substance users. That is, childhood sexual abuse would be associated with risky sex behaviors, childhood physical abuse with aggression, and childhood emotional abuse with emotion dysregulation. 280 inpatients (M age=43.3; 69.7% male; 88.4% African American) in substance use treatment completed the Childhood Trauma Questionnaire (CTQ), HIV Risk-Taking Behavior Scale, Addiction Severity Index, Difficulties with Emotion Regulation Scale (DERS), Distress Tolerance Scale (DTS), and Affect Intensity and Dimensions of Affiliation Motivation (AIM). Consistent with our hypotheses, the CTQ sexual abuse subscale uniquely predicted exchanging sex for cocaine and heroin, number of arrests for prostitution, engaging in unprotected sex with a casual partner during the prior year, and experiencing low sexual arousal when sober. The physical abuse subscale uniquely predicted number of arrests for assault and weapons offenses. The emotional abuse subscale uniquely predicted the DERS total score, AIM score, and DTS score. Among substance users, different types of abuse are uniquely associated with specific negative effects. Assessment of specific abuse types among substance users may be informative in treatment planning and relapse prevention. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Meerkat close calling patterns are linked to sex, social category, season and wind, but not fecal glucocorticoid metabolite concentrations.

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    Jelena Mausbach

    Full Text Available It is well established that animal vocalizations can encode information regarding a sender's identity, sex, age, body size, social rank and group membership. However, the association between physiological parameters, particularly stress hormone levels, and vocal behavior is still not well understood. The cooperatively breeding African meerkats (Suricata suricatta live in family groups with despotic social hierarchies. During foraging, individuals emit close calls that help maintain group cohesion. These contact calls are acoustically distinctive and variable in rate across individuals, yet, information on which factors influence close calling behavior is missing. The aim of this study was to identify proximate factors that influence variation in call rate and acoustic structure of meerkat close calls. Specifically, we investigated whether close calling behavior is associated with sex, age and rank, or stress hormone output (i.e., measured as fecal glucocorticoid metabolite (fGCM concentrations as individual traits of the caller, as well as with environmental conditions (weather and reproductive seasonality. To disentangle the effects of these factors on vocal behavior, we analyzed sound recordings and assessed fGCM concentrations in 64 wild but habituated meerkats from 9 groups during the reproductive and non-reproductive seasons. Dominant females and one-year old males called at significantly higher rates compared to other social categories during the reproductive season. Additionally, dominant females produced close calls with the lowest mean fundamental frequencies (F0 and the longest mean pulse durations. Windy conditions were associated with significantly higher call rates during the non-reproductive season. Fecal GCM concentrations were unrelated to close calling behavior. Our findings suggest that meerkat close calling behavior conveys information regarding the sex and social category of the caller, but shows no association with f

  4. Young men’s shame about their desire for other men predicts risky sex and moderates the knowledge - self-efficacy link.

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    Mina ePark

    2014-10-01

    Full Text Available Background: Recent findings suggest that a strong negative social emotion (i.e., shame increases YMSM’s sexual risk-taking. Unchangeable shame (e.g., desire for other men might undermine (moderate the link between knowledge and self-efficacy or between self-efficacy and unprotected anal intercourse (UAI: This may be less likely for changeable shame (e.g., shame about risky sexual behavior.Aim: To test the hypotheses that shame (i.e., sexual desire shame, but not shame about behavior (i.e., sexual behavior shame, will be positively related to UAI and will moderate the relationship between knowledge and self-efficacy and/or self-efficacy and UAI among YMSM.Method: In an online national study, 1177 young adult (18-24 year old MSM reported one or more acts of UAI in the past 90 days with a casual partner. Eligible MSM filled out a survey in which they provided information about their knowledge of safer sex, self-efficacy for safer sex, reported levels of shame, and reported past 90-day UAI. Results: Sexual desire shame was negatively correlated with knowledge and self-efficacy and positively correlated with UAI: The pattern reversed for sexual behavior shame. Sexual desire shame significantly lowered the knowledge to self-efficacy and the self-efficacy to UAI links. Sexual behavior shame also reduced the link from knowledge to self-efficacy, but not the self-efficacy to UAI link. Conclusion: The present study shows that there are different types of shame that may produce different effects with different implications for health behavior. Sexual desire shame may better reflect an emotion that is activated prior to risky behavior (e.g., when men reflect upon or feel desire for another man. Sexual behavior shame, on the other hand, better reflects what has already happened: Thus, those higher in knowledge, efficacy, and therefore safer sex are least likely to experience shame behavior.

  5. The endocrine stress response is linked to one specific locus on chromosome 3 in a mouse model based on extremes in trait anxiety

    Directory of Open Access Journals (Sweden)

    Gonik Mariya

    2012-10-01

    Full Text Available Abstract Background The hypothalamic-pituitary-adrenal (HPA axis is essential to control physiological stress responses in mammals. Its dysfunction is related to several mental disorders, including anxiety and depression. The aim of this study was to identify genetic loci underlying the endocrine regulation of the HPA axis. Method High (HAB and low (LAB anxiety-related behaviour mice were established by selective inbreeding of outbred CD-1 mice to model extremes in trait anxiety. Additionally, HAB vs. LAB mice exhibit comorbid characteristics including a differential corticosterone response upon stress exposure. We crossbred HAB and LAB lines to create F1 and F2 offspring. To identify the contribution of the endocrine phenotypes to the total phenotypic variance, we examined multiple behavioural paradigms together with corticosterone secretion-based phenotypes in F2 mice by principal component analysis. Further, to pinpoint the genomic loci of the quantitative trait of the HPA axis stress response, we conducted genome-wide multipoint oligogenic linkage analyses based on Bayesian Markov chain Monte Carlo approach as well as parametric linkage in three-generation pedigrees, followed by a two-dimensional scan for epistasis and association analysis in freely segregating F2 mice using 267 single-nucleotide polymorphisms (SNPs, which were identified to consistently differ between HAB and LAB mice as genetic markers. Results HPA axis reactivity measurements and behavioural phenotypes were represented by independent principal components and demonstrated no correlation. Based on this finding, we identified one single quantitative trait locus (QTL on chromosome 3 showing a very strong evidence for linkage (2ln (L-score > 10, LOD > 23 and significant association (lowest Bonferroni adjusted p -28 to the neuroendocrine stress response. The location of the linkage peak was estimated at 42.3 cM (95% confidence interval: 41.3 - 43.3 cM and was shown to be in

  6. Efficient identification of Y chromosome sequences in the human and Drosophila genomes

    Science.gov (United States)

    Carvalho, Antonio Bernardo; Clark, Andrew G.

    2013-01-01

    Notwithstanding their biological importance, Y chromosomes remain poorly known in most species. A major obstacle to their study is the identification of Y chromosome sequences; due to its high content of repetitive DNA, in most genome projects, the Y chromosome sequence is fragmented into a large number of small, unmapped scaffolds. Identification of Y-linked genes among these fragments has yielded important insights about the origin and evolution of Y chromosomes, but the process is labor intensive, restricting studies to a small number of species. Apart from these fragmentary assemblies, in a few mammalian species, the euchromatic sequence of the Y is essentially complete, owing to painstaking BAC mapping and sequencing. Here we use female short-read sequencing and k-mer comparison to identify Y-linked sequences in two very different genomes, Drosophila virilis and human. Using this method, essentially all D. virilis scaffolds were unambiguously classified as Y-linked or not Y-linked. We found 800 new scaffolds (totaling 8.5 Mbp), and four new genes in the Y chromosome of D. virilis, including JYalpha, a gene involved in hybrid male sterility. Our results also strongly support the preponderance of gene gains over gene losses in the evolution of the Drosophila Y. In the intensively studied human genome, used here as a positive control, we recovered all previously known genes or gene families, plus a small amount (283 kb) of new, unfinished sequence. Hence, this method works in large and complex genomes and can be applied to any species with sex chromosomes. PMID:23921660

  7. Efficient identification of Y chromosome sequences in the human and Drosophila genomes.

    Science.gov (United States)

    Carvalho, Antonio Bernardo; Clark, Andrew G

    2013-11-01

    Notwithstanding their biological importance, Y chromosomes remain poorly known in most species. A major obstacle to their study is the identification of Y chromosome sequences; due to its high content of repetitive DNA, in most genome projects, the Y chromosome sequence is fragmented into a large number of small, unmapped scaffolds. Identification of Y-linked genes among these fragments has yielded important insights about the origin and evolution of Y chromosomes, but the process is labor intensive, restricting studies to a small number of species. Apart from these fragmentary assemblies, in a few mammalian species, the euchromatic sequence of the Y is essentially complete, owing to painstaking BAC mapping and sequencing. Here we use female short-read sequencing and k-mer comparison to identify Y-linked sequences in two very different genomes, Drosophila virilis and human. Using this method, essentially all D. virilis scaffolds were unambiguously classified as Y-linked or not Y-linked. We found 800 new scaffolds (totaling 8.5 Mbp), and four new genes in the Y chromosome of D. virilis, including JYalpha, a gene involved in hybrid male sterility. Our results also strongly support the preponderance of gene gains over gene losses in the evolution of the Drosophila Y. In the intensively studied human genome, used here as a positive control, we recovered all previously known genes or gene families, plus a small amount (283 kb) of new, unfinished sequence. Hence, this method works in large and complex genomes and can be applied to any species with sex chromosomes.

  8. Molecular sexing of tucuxi dolphins (Sotalia guianensis and Sotalia fluviatilis using samples from biopsy darting and decomposed carcasses

    Directory of Open Access Journals (Sweden)

    Haydée A. Cunha

    2007-01-01

    Full Text Available We tested the zinc-finger sex chromosome-linked genes Zfx/Zfy and the sex-determining region Y (Sry genes for gender determination of biopsy samples from marine and riverine tucuxi dolphins (Sotalia guianensis and S. fluviatilis. We also evaluated the performance of these genes with decomposed carcasses, for which sexing cannot rely on the direct examination of the reproductive tract. Both systems proved reliable for sexing 46 fresh and decomposed samples, making them especially useful when biopsy darting is coupled with photo-identification studies.

  9. Comparative Genomic Hybridization (CGH) reveals a neo-X chromosome and biased gene movement in stalk-eyed flies (genus Teleopsis).

    Science.gov (United States)

    Baker, Richard H; Wilkinson, Gerald S

    2010-09-16

    Chromosomal location has a significant effect on the evolutionary dynamics of genes involved in sexual dimorphism, impacting both the pattern of sex-specific gene expression and the rate of duplication and protein evolution for these genes. For nearly all non-model organisms, however, knowledge of chromosomal gene content is minimal and difficult to obtain on a genomic scale. In this study, we utilized Comparative Genomic Hybridization (CGH), using probes designed from EST sequence, to identify genes located on the X chromosome of four species in the stalk-eyed fly genus Teleopsis. Analysis of log(2) ratio values of female-to-male hybridization intensities from the CGH microarrays for over 3,400 genes reveals a strongly bimodal distribution that clearly differentiates autosomal from X-linked genes for all four species. Genotyping of 33 and linkage mapping of 28 of these genes in Teleopsis dalmanni indicate the CGH results correctly identified chromosomal location in all cases. Syntenic comparison with Drosophila indicates that 90% of the X-linked genes in Teleopsis are homologous to genes located on chromosome 2L in Drosophila melanogaster, suggesting the formation of a nearly complete neo-X chromosome from Muller element B in the dipteran lineage leading to Teleopsis. Analysis of gene movement both relative to Drosophila and within Teleopsis indicates that gene movement is significantly associated with 1) rates of protein evolution, 2) the pattern of gene duplication, and 3) the evolution of eyespan sexual dimorphism. Overall, this study reveals that diopsids are a critical group for understanding the evolution of sex chromosomes within Diptera. In addition, we demonstrate that CGH is a useful technique for identifying chromosomal sex-linkage and should be applicable to other organisms with EST or partial genomic information.

  10. Comparative Genomic Hybridization (CGH reveals a neo-X chromosome and biased gene movement in stalk-eyed flies (genus Teleopsis.

    Directory of Open Access Journals (Sweden)

    Richard H Baker

    2010-09-01

    Full Text Available Chromosomal location has a significant effect on the evolutionary dynamics of genes involved in sexual dimorphism, impacting both the pattern of sex-specific gene expression and the rate of duplication and protein evolution for these genes. For nearly all non-model organisms, however, knowledge of chromosomal gene content is minimal and difficult to obtain on a genomic scale. In this study, we utilized Comparative Genomic Hybridization (CGH, using probes designed from EST sequence, to identify genes located on the X chromosome of four species in the stalk-eyed fly genus Teleopsis. Analysis of log(2 ratio values of female-to-male hybridization intensities from the CGH microarrays for over 3,400 genes reveals a strongly bimodal distribution that clearly differentiates autosomal from X-linked genes for all four species. Genotyping of 33 and linkage mapping of 28 of these genes in Teleopsis dalmanni indicate the CGH results correctly identified chromosomal location in all cases. Syntenic comparison with Drosophila indicates that 90% of the X-linked genes in Teleopsis are homologous to genes located on chromosome 2L in Drosophila melanogaster, suggesting the formation of a nearly complete neo-X chromosome from Muller element B in the dipteran lineage leading to Teleopsis. Analysis of gene movement both relative to Drosophila and within Teleopsis indicates that gene movement is significantly associated with 1 rates of protein evolution, 2 the pattern of gene duplication, and 3 the evolution of eyespan sexual dimorphism. Overall, this study reveals that diopsids are a critical group for understanding the evolution of sex chromosomes within Diptera. In addition, we demonstrate that CGH is a useful technique for identifying chromosomal sex-linkage and should be applicable to other organisms with EST or partial genomic information.

  11. Fine mapping of dominant X-linked incompatibility alleles in Drosophila hybrids.

    Science.gov (United States)

    Matute, Daniel R; Gavin-Smyth, Jackie

    2014-04-01

    Sex chromosomes have a large effect on reproductive isolation and play an important role in hybrid inviability. In Drosophila hybrids, X-linked genes have pronounced deleterious effects on fitness in male hybrids, which have only one X chromosome. Several studies have succeeded at locating and identifying recessive X-linked alleles involved in hybrid inviability. Nonetheless, the density of dominant X-linked alleles involved in interspecific hybrid viability remains largely unknown. In this report, we study the effects of a panel of small fragments of the D. melanogaster X-chromosome carried on the D. melanogaster Y-chromosome in three kinds of hybrid males: D. melanogaster/D. santomea, D. melanogaster/D. simulans and D. melanogaster/D. mauritiana. D. santomea and D. melanogaster diverged over 10 million years ago, while D. simulans (and D. mauritiana) diverged from D. melanogaster over 3 million years ago. We find that the X-chromosome from D. melanogaster carries dominant alleles that are lethal in mel/san, mel/sim, and mel/mau hybrids, and more of these alleles are revealed in the most divergent cross. We then compare these effects on hybrid viability with two D. melanogaster intraspecific crosses. Unlike the interspecific crosses, we found no X-linked alleles that cause lethality in intraspecific crosses. Our results reveal the existence of dominant alleles on the X-chromosome of D. melanogaster which cause lethality in three different interspecific hybrids. These alleles only cause inviability in hybrid males, yet have little effect in hybrid females. This suggests that X-linked elements that cause hybrid inviability in males might not do so in hybrid females due to differing sex chromosome interactions.

  12. Ehlers-Danlos Syndrome, Hypermobility Type, Is Linked to Chromosome 8p22-8p21.1 in an Extended Belgian Family

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    Delfien Syx

    2015-01-01

    Full Text Available Joint hypermobility is a common, mostly benign, finding in the general population. In a subset of individuals, however, it causes a range of clinical problems, mainly affecting the musculoskeletal system. Joint hypermobility often appears as a familial trait and is shared by several heritable connective tissue disorders, including the hypermobility subtype of the Ehlers-Danlos syndrome (EDS-HT or benign joint hypermobility syndrome (BJHS. These hereditary conditions provide unique models for the study of the genetic basis of joint hypermobility. Nevertheless, these studies are largely hampered by the great variability in clinical presentation and the often vague mode of inheritance in many families. Here, we performed a genome-wide linkage scan in a unique three-generation family with an autosomal dominant EDS-HT phenotype and identified a linkage interval on chromosome 8p22-8p21.1, with a maximum two-point LOD score of 4.73. Subsequent whole exome sequencing revealed the presence of a unique missense variant in the LZTS1 gene, located within the candidate region. Subsequent analysis of 230 EDS-HT/BJHS patients resulted in the identification of three additional rare variants. This is the first reported genome-wide linkage analysis in an EDS-HT family, thereby providing an opportunity to identify a new disease gene for this condition.

  13. A sexy spin on nonrandom chromosome segregation.

    Science.gov (United States)

    Charville, Gregory W; Rando, Thomas A

    2013-06-06

    Nonrandom chromosome segregation is an intriguing phenomenon linked to certain asymmetric stem cell divisions. In a recent report in Nature, Yadlapalli and Yamashita (2013) observe nonrandom segregation of X and Y chromosomes in Drosophila germline stem cells and shed light on the complex mechanisms of this fascinating process. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Autosomal dominant hereditary sensory neuropathy with chronic cough and gastro-oesophageal reflux: clinical features in two families linked to chromosome 3p22-p24.

    Science.gov (United States)

    Spring, Penelope J; Kok, Cindy; Nicholson, Garth A; Ing, Alvin J; Spies, Judith M; Bassett, Mark L; Cameron, John; Kerlin, Paul; Bowler, Simon; Tuck, Roger; Pollard, John D

    2005-12-01

    Autosomal dominant hereditary sensory neuropathy (HSN I) is a clinically and genetically heterogeneous group of disorders, and in some families it is due to mutations in the serine palmitoyltransferase (SPTLC1) gene. We have characterized two families with HSN I associated with cough and gastro-oesophageal reflux (GOR). From a large Australian family, 27 individuals and from a smaller family, 11 individuals provided clinical information and blood for genetic analysis. Affected individuals had an adult onset of paroxysmal cough, GOR and distal sensory loss. Cough could be triggered by noxious odours or by pressure in the external auditory canal (Arnold's ear-cough reflex). Other features included throat clearing, hoarse voice, cough syncope and sensorineural hearing loss. Neurophysiological and pathological studies demonstrated a sensory axonal neuropathy. Gastric emptying studies were normal, and autonomic function and sweat tests were either normal or showed distal hypohidrosis. Cough was likely to be due to a combination of denervation hypersensitivity of the upper airways and oesophagus, and prominent GOR. Most affected individuals were shown on 24 h ambulatory oesophageal pH monitoring to have multiple episodes of GOR, closely temporally associated with coughing. Hoarse voice was probably attributable to acid-induced laryngeal damage, and there was no evidence of vocal cord palsy. No other cause for cough was found on most respiratory or otorhinological studies. Linkage to chromosome 3p22-p24 has been found in both families, with no evidence of linkage to loci for known HSN I, autosomal dominant hereditary motor and sensory neuropathy, hereditary GOR or triple A syndrome. These families represent a genetically novel variant of HSN I, with a distinctive cough owing to involvement of the upper aerodigestive tract.

  15. Demasculinization of the Anopheles gambiae X chromosome

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    Magnusson Kalle

    2012-05-01

    Full Text Available Abstract Background In a number of organisms sex-biased genes are non-randomly distributed between autosomes and the shared sex chromosome X (or Z. Studies on Anopheles gambiae have produced conflicting results regarding the underrepresentation of male-biased genes on the X chromosome and it is unclear to what extent sexual antagonism, dosage compensation or X-inactivation in the male germline, the evolutionary forces that have been suggested to affect the chromosomal distribution of sex-biased genes, are operational in Anopheles. Results We performed a meta-analysis of sex-biased gene expression in Anopheles gambiae which provides evidence for a general underrepresentation of male-biased genes on the X-chromosome that increased in significance with the observed degree of sex-bias. A phylogenomic comparison between Drosophila melanogaster, Aedes aegypti and Culex quinquefasciatus also indicates that the Anopheles X chromosome strongly disfavours the evolutionary conservation of male-biased expression and that novel male-biased genes are more likely to arise on autosomes. Finally, we demonstrate experimentally that transgenes situated on the Anopheles gambiae X chromosome are transcriptionally silenced in the male germline. Conclusion The data presented here support the hypothesis that the observed demasculinization of the Anopheles X chromosome is driven by X-chromosome inactivation in the male germline and by sexual antagonism. The demasculinization appears to be the consequence of a loss of male-biased expression, rather than a failure in the establishment or the extinction of male-biased genes.

  16. RNA sequencing reveals sexually dimorphic gene expression before gonadal differentiation in chicken and allows comprehensive annotation of the W-chromosome

    Science.gov (United States)

    2013-01-01

    Background Birds have a ZZ male: ZW female sex chromosome system and while the Z-linked DMRT1 gene is necessary for testis development, the exact mechanism of sex determination in birds remains unsolved. This is partly due to the poor annotation of the W chromosome, which is speculated to carry a female determinant. Few genes have been mapped to the W and little is known of their expression. Results We used RNA-seq to produce a comprehensive profile of gene expression in chicken blastoderms and embryonic gonads prior to sexual differentiation. We found robust sexually dimorphic gene expression in both tissues pre-dating gonadogenesis, including sex-linked and autosomal genes. This supports the hypothesis that sexual differentiation at the molecular level is at least partly cell autonomous in birds. Different sets of genes were sexually dimorphic in the two tissues, indicating that molecular sexual differentiation is tissue specific. Further analyses allowed the assembly of full-length transcripts for 26 W chromosome genes, providing a view of the W transcriptome in embryonic tissues. This is the first extensive analysis of W-linked genes and their expression profiles in early avian embryos. Conclusion Sexual differentiation at the molecular level is established in chicken early in embryogenesis, before gonadal sex differentiation. We find that the W chromosome is more transcriptionally active than previously thought, expand the number of known genes to 26 and present complete coding sequences for these W genes. This includes two novel W-linked sequences and three small RNAs reassigned to the W from the Un_Random chromosome. PMID:23531366

  17. Analysis of the Ceratitis capitata y chromosome using in situ hybridization to mitotic chromosomes

    International Nuclear Information System (INIS)

    Willhoeft, U.; Franz, G.

    1998-01-01

    In Ceratitis capitata the Y chromosome is responsible for sex-determination. We used fluorescence in situ hybridization (FISH) for cytogenetic analysis of mitotic chromosomes. FISH with the wild-type strain EgyptII and two repetitive DNA probes enabled us to differentiate between the short and the long arm of the Y chromosome and gives a much better resolution than C-banding of mitotic chromosomes. We identified the Y-chromosomal breakpoints in Y-autosome translocations using FISH. Even more complex rearrangements i.e. deletions and insertions in some translocation strains were detected by this method. A strategy for mapping the primary sex determination factor in Ceratitis capitata by FISH is presented. (author)

  18. Sex linked versus autosomal inbreeding coefficient in close consanguineous marriages in the Basque country and Castile (Spain): genetic implications.

    Science.gov (United States)

    Calderón, R; Morales, B; Peña, J A; Delgado, J

    1995-10-01

    Pedigree structures of 161 uncle/niece-aunt/nephew and 4420 first cousin consanguineous marriages registered during the 19th and 20th centuries in two large and very different Spanish regions have been analysed and their genetic consequences evaluated. The frequencies of the different pedigree subtypes within each degree of relationship were quite similar in both populations despite significant heterogeneity in inbreeding patterns. The mean X-linked inbreeding coefficient (Fx) for each type of cousin mating was calculated and compared to that expected for autosomal genes (F). The effect of genealogical structure on the Fx/F ratio was compared to different cultural populations worldwide. Preferentiality and avoidance of close consanguinity along with specific types of pedigrees are discussed on the basis of premarital migration and sociocultural rules still deeply rooted in certain human groups. By admitting that the observed Fx coefficient is usually higher than F in most human populations some remarks have been made in terms of population genetic risk.

  19. Sucrose feeding in mouse pregnancy leads to hypertension, and sex-linked obesity and insulin resistance in female offspring

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    Anne-Maj eSamuelsson

    2013-02-01

    Full Text Available Eating an unbalanced diet during pregnancy may induce long-term health consequences in offspring, in particular obesity, insulin resistance and hypertension. We tested the hypothesis that a maternal diet rich in simple sugars predispose mouse offspring to obesity, glucose intolerance and cardiovascular diseases in adulthood.Female C57BL/6J mice were fed either a standard chow or a sucrose-rich diet (26% of total energy 6 weeks prior to mating, throughout pregnancy and lactation. Offspring of control dams (OC and high sucrose fed dams (OSF were weaned onto standard control chow, and metabolic and cardiovascular parameters determined at 3 months of age. Both male and female OSF were hyperphagic by 4 weeks of age and females were heavier than OC at 9 weeks. At 3 months, female OSF showed a significant increase in inguinal fat pad mass, whereas skeletal muscle mass (tibialis anterior and locomotor activity were decreased relative to OC. A ten-fold increase in fasting serum insulin in female OSF versus OC at 3 months (Insulin [pmol/L] mean±SEM, OSF, 200.3±16.1, versus OC, 20.3±1.8, n=6 P<0.001, was associated with impaired glucose tolerance (AUC [mmol/L min] mean±SEM, OSF 1437.4±124.2 versus OC, 1076.8±83.9, n=6, P<0.05. Both male and female OSF were hypertensive as assessed by radiotelemetry (night-time systolic arterial pressure [mmHg] mean±SEM, male OSF, 128±1 versus OC, 109±1, n=6, P<0.01; female OSF, 130±1 versus OC, 118±1, n=6, P<0.05. Analysis of heart rate variability demonstrated an increased low:high frequency ratio in male and female OSF (P<0.05, indicative of heightened sympathetic efferent tone. Renal tissue noradrenaline content was markely raised in the OSF versus OC (noradrenaline [pg/ml/mg tissue] mean±SEM, male OSF, 2.28±0.19 versus OC 0.84±0.09, n=6, P<0.01 . Exposure to a maternal diet rich in sucrose led to obesity and glucose intolerance in female mice offspring, and hypertension in both sexes.

  20. Linking young men who have sex with men (YMSM) to STI physicians: a nationwide cross-sectional survey in China.

    Science.gov (United States)

    Cao, Bolin; Zhao, Peipei; Bien, Cedric; Pan, Stephen; Tang, Weiming; Watson, Julia; Mi, Guodong; Ding, Yi; Luo, Zhenzhou; Tucker, Joseph D

    2018-05-18

    Many young men who have sex with men (YMSM) are reluctant to seek health services and trust local physicians. Online information seeking may encourage YMSM to identify and see trustworthy physicians, obtain sexual health services, and obtain testing for sexually transmitted infections (STIs). This study examined online STI information seeking behaviors among Chinese YMSM and its association with offline physician visits. We conducted a nationwide online survey among YMSM through WeChat, the largest social media platform in China. We collected information on individual demographics, sexual behaviors, online STI information seeking, offline STI testing, and STI physician visits. We examined the most commonly used platforms (search engines, governmental websites, counseling websites, generic social media, gay mobile apps, and mobile medical apps) and their trustworthiness. We assessed interest and willingness to use an MSM-friendly physician finder function embedded within a gay mobile app. Logistic regression models were used to examine the correlation between online STI information searching and offline physician visits. A total of 503 men completed the survey. Most men (425/503, 84.5%) searched for STI information online. The most commonly used platform to obtain STI information were search engines (402/425, 94.5%), followed by gay mobile apps (201/425, 47.3%). Men reported high trustworthiness of information received from gay mobile apps. Men also reported high interest (465/503, 92.4%) and willingness (463/503, 92.0%) to use a MSM-friendly physician finder function within such apps. Both using general social media (aOR =1.14, 95%CI: 1.04-1.26) and mobile medical apps (aOR =1.16, 95%CI: 1.01-1.34) for online information seeking were associated with visiting a physician. Online STI information seeking is common and correlated with visiting a physician among YMSM. Cultivating partnerships with the emerging mobile medical apps may be useful for disseminating STI

  1. Chromosome Abnormalities

    Science.gov (United States)

    ... Care Genomic Medicine Working Group New Horizons and Research Patient Management Policy and Ethics Issues Quick Links for Patient Care Education All About the Human Genome Project Fact Sheets Genetic Education Resources for ...

  2. Chromosomal instability can be induced by the formation of breakage-prone chromosome rearrangement junctions

    International Nuclear Information System (INIS)

    Allen, R.N.; Ritter, L.; Moore, S.R.; Grosovsky, A.J.

    2003-01-01

    Full text: Studies in our lab have led to the hypothesis that chromosomal rearrangements can generate novel breakage-prone sites, resulting in chromosomal instability acting predominantly in cis. For example, specific breakage of large blocks of centromeric region heterochromatin on chromosome 16q by treatment with 2,6-diaminopurine (DAP) is associated with repeated rearrangement of chromosome 16q during outgrowth of DAP-treated clones, thereby establishing a link between the initial site of damage and the occurrence of persistent chromosomal instability. Similarly, karyotypic analysis of gamma ray induced instability demonstrated that chromosomal rearrangements in sub-clones were significantly clustered near the site of previously identified chromosomal rearrangement junctions in unstable parental clones. This study investigates the hypothesis that integration of transfected sequences into host chromosomes could create breakage-prone junction regions and persistent genomic instability without exposure to DNA-damage agents. These junctions may mimic the unstable chromosomal rearrangements induced by DAP or radiation, and thus provide a test of the broader hypothesis that instability can to some extent be attributed to the formation of novel chromosomal breakage hot spots. These experiments were performed using human-hamster hybrid AL cells containing a single human chromosome 11, which was used to monitor instability in a chromosomal painting assay. AL cells were transfected with a 2.5 Kb fragment containing multiple copies of the 180 bp human alpha heterochromatic repeat, which resulted in chromosomal instability in 41% of the transfected clones. Parallel exposure to gamma-radiation resulted in a similar level of chromosomal instability, although control transfections with plasmid alone did not lead to karyotypic instability. Chromosomal instability induced by integration of alpha heterochromatic repeats was also frequently associated with delayed reproductive

  3. Reduced polymorphism associated with X chromosome meiotic drive in the stalk-eyed fly Teleopsis dalmanni.

    Directory of Open Access Journals (Sweden)

    Sarah J Christianson

    Full Text Available Sex chromosome meiotic drive has been suggested as a cause of several evolutionary genetic phenomena, including genomic conflicts that give rise to reproductive isolation between new species. In this paper we present a population genetic analysis of X chromosome drive in the stalk-eyed fly, Teleopsis dalmanni, to determine how this natural polymorphism influences genetic diversity. We analyzed patterns of DNA sequence variation at two X-linked regions (comprising 1325 bp approximately 50 cM apart and one autosomal region (comprising 921 bp for 50 males, half of which were collected in the field from one of two allopatric locations and the other half were derived from lab-reared individuals with known brood sex ratios. These two populations are recently diverged but exhibit partial postzygotic reproductive isolation, i.e. crosses produce sterile hybrid males and fertile females. We find no nucleotide or microsatellite variation on the drive X chromosome, whereas the same individuals show levels of variation at autosomal regions that are similar to field-collected flies. Furthermore, one field-caught individual collected 10 years previously had a nearly identical X haplotype to the drive X, and is over 2% divergent from other haplotypes sampled from the field. These results are consistent with a selective sweep that has removed genetic variation from much of the drive X chromosome. We discuss how this finding may relate to the rapid evolution of postzygotic reproductive isolation that has been documented for these flies.

  4. Using technology, choosing sex. The campaign against sex determination and the question of choice.

    Science.gov (United States)

    1992-01-01

    Women's groups and people's science and health groups formed the Forum Against Sex Determination and Sex Pre-Selection in November 1985 in Bombay, India, to prevent sex determination and sex preselection tests. The Forum considered sex determination and sex preselection to be an abuse of science and technology against people, especially women. Between 1901 and 1991, the sex ratio fell from 972 females/1000 males to 929/1000. The Forum saw the issue of sex determination and sex preselection as a link to oppression of and discrimination against females in all sectors of society. It also believed this to be a human rights issue. The Forum lobbied for a law regulating diagnostic techniques without banning them, since determining chromosomal abnormalities is important. The State of Maharashtra passed such a law in June 1988. It had some provisions which were counter-productive, however. For example, women undergoing a sex determination test must pay a fine of Rs 5 if found guilty of planning to terminate a pregnancy of a female fetus. Yet, neither the husband nor parents-in-law are liable, even though they often pressure women to undergo sex determination tests. The Forum's efforts and enactment of the law in Maharashtra have prompted other state governments and the central government to propose similar legislation. These state governments include Goa, Gujarat, and Orissa. The central government has met with organizations and individuals lobbying against misuse of diagnostic tests to obtain their counsel. The Forum does not feel comfortable with state control, however, since it tends to consider government to be against the people. Yet, the Forum did want the state to protect women's interests. It has raised important questions about technology, particularly concerning criteria to determine desirable and appropriate technologies.

  5. Unequal rates of Y chromosome gene divergence during speciation of the family Ursidae.

    Science.gov (United States)

    Nakagome, Shigeki; Pecon-Slattery, Jill; Masuda, Ryuichi

    2008-07-01

    Evolution of the bear family Ursidae is well investigated in terms of morphological, paleontological, and genetic features. However, several phylogenetic ambiguities occur within the subfamily Ursinae (the family Ursidae excluding the giant panda and spectacled bear), which may correlate with behavioral traits of female philopatry and male-biased dispersal which form the basis of the observed matriarchal population structure in these species. In the process of bear evolution, we investigate the premise that such behavioral traits may be reflected in patterns of variation among genes with different modes of inheritance: matrilineal mitochondrial DNA (mtDNA), patrilineal Y chromosome, biparentally inherited autosomes, and the X chromosome. In the present study, we sequenced 3 Y-linked genes (3,453 bp) and 4 X-linked genes (4,960 bp) and reanalyzed previously published sequences from autosome genes (2,347 bp) in ursid species to investigate differences in evolutionary rates associated with patterns of inheritance. The results describe topological incongruence between sex-linked genes and autosome genes and between nuclear DNA and mtDNA. In more ancestral branches within the bear phylogeny, Y-linked genes evolved faster than autosome and X-linked genes, consistent with expectations based on male-driven evolution. However, this pattern changes among branches leading to each species within the lineage of Ursinae whereby the evolutionary rates of Y-linked genes have fewer than expected substitutions. This inconsistency between more recent nodes of the bear phylogeny with more ancestral nodes may reflect the influences of sex-biased dispersal as well as molecular evolutionary characteristics of the Y chromosome, and stochastic events in species natural history, and phylogeography unique to ursine bears.

  6. Everyday executive functions in Down syndrome from early childhood to young adulthood: evidence for both unique and shared characteristics compared to youth with sex chromosome trisomy (XXX and XXY).

    Science.gov (United States)

    Lee, Nancy Raitano; Anand, Payal; Will, Elizabeth; Adeyemi, Elizabeth I; Clasen, Liv S; Blumenthal, Jonathan D; Giedd, Jay N; Daunhauer, Lisa A; Fidler, Deborah J; Edgin, Jamie O

    2015-01-01

    Executive functions (EF) are thought to be impaired in Down syndrome (DS) and sex chromosome trisomy (Klinefelter and Trisomy X syndromes; +1X). However, the syndromic specificity and developmental trajectories associated with EF difficulties in these groups are poorly understood. The current investigation (a) compared everyday EF difficulties in youth with DS, +1X, and typical development (TD); and (b) examined relations between age and EF difficulties in these two groups and a TD control group cross-sectionally. Study 1 investigated the syndromic specificity of EF profiles on the Behavior Rating Inventory of Executive Function (BRIEF) in DS (n = 30), +1X (n = 30), and a TD group (n = 30), ages 5-18 years. Study 2 examined age effects on EF in the same cross-sectional sample of participants included in Study 1. Study 3 sought to replicate Study 2's findings for DS by examining age-EF relations in a large independent sample of youth with DS (n = 85) and TD (n = 43), ages 4-24 years. Study 1 found evidence for both unique and shared EF impairments for the DS and +1X groups. Most notably, youth with +1X had relatively uniform EF impairments on the BRIEF scales, while the DS group showed an uneven BRIEF profile with relative strengths and weaknesses. Studies 2 and 3 provided support for fairly similar age-EF relations in the DS and TD groups. In contrast, for the +1X group, findings were mixed; 6 BRIEF scales showed similar age-EF relations to the TD group and 2 showed greater EF difficulties at older ages for +1X. These findings will be discussed within the context of efforts to identify syndrome specific cognitive-behavioral profiles for youth with different genetic syndromes in order to inform basic science investigations into the etiology of EF difficulties in these groups and to develop treatment approaches that are tailored to the needs of these groups.

  7. Chromosomal Translocations in Black Flies (Diptera: Simuliidae-Facilitators of Adaptive Radiation?

    Directory of Open Access Journals (Sweden)

    Peter H Adler

    Full Text Available A macrogenomic investigation of a Holarctic clade of black flies-the Simulium cholodkovskii lineage-provided a platform to explore the implications of a unique, synapomorphic whole-arm interchange in the evolution of black flies. Nearly 60 structural rearrangements were discovered in the polytene complement of the lineage, including 15 common to all 138 analyzed individuals, relative to the central sequence for the entire subgenus Simulium. Three species were represented, of which two Palearctic entities (Simulium cholodkovskii and S. decimatum were sympatric; an absence of hybrids confirmed their reproductive isolation. A third (Nearctic entity had nonhomologous sex chromosomes, relative to the other species, and is considered a separate species, for which the name Simulium nigricoxum is revalidated. A cytophylogeny is inferred and indicates that the two Palearctic taxa are sister species and these, in turn, are the sister group of the Nearctic species. The rise of the S. cholodkovskii lineage encompassed complex chromosomal and genomic restructuring phenomena associated with speciation in black flies, viz. expression of one and the same rearrangement as polymorphic, fixed, or sex linked in different species; taxon-specific differentiation of sex chromosomes; and reciprocal translocation of chromosome arms. The translocation is hypothesized to have occurred early in male spermatogonia, with the translocated chromosomal complement being transmitted to the X- and Y-bearing sperm during spermatogenesis, resulting in alternate disjunction of viable F1 translocation heterozygotes and the eventual formation of more viable and selectable F2 translocation homozygous progeny. Of 11 or 12 independently derived whole-arm interchanges known in the family Simuliidae, at least six are associated with subsequent speciation events, suggesting a facilitating role of translocations in adaptive radiations. The findings are discussed in the context of potential

  8. Sexual antagonism and meiotic drive cause stable linkage disequilibrium and favour reduced recombination on the X chromosome.

    Science.gov (United States)

    Rydzewski, W T; Carioscia, S A; Liévano, G; Lynch, V D; Patten, M M

    2016-06-01

    Sexual antagonism and meiotic drive are sex-specific evolutionary forces with the potential to shape genomic architecture. Previous theory has found that pairing two sexually antagonistic loci or combining sexual antagonism with meiotic drive at linked autosomal loci augments genetic variation, produces stable linkage disequilibrium (LD) and favours reduced recombination. However, the influence of these two forces has not been examined on the X chromosome, which is thought to be enriched for sexual antagonism and meiotic drive. We investigate the evolution of the X chromosome under both sexual antagonism and meiotic drive with two models: in one, both loci experience sexual antagonism; in the other, we pair a meiotic drive locus with a sexually antagonistic locus. We find that LD arises between the two loci in both models, even when the two loci freely recombine in females and that driving haplotypes will be enriched for male-beneficial alleles, further skewing sex ratios in these populations. We introduce a new measure of LD, Dz', which accounts for population allele frequencies and is appropriate for instances where these are sex specific. Both models demonstrate that natural selection favours modifiers that reduce the recombination rate. These results inform observed patterns of congealment found on driving X chromosomes and have implications for patterns of natural variation and the evolution of recombination rates on the X chromosome. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  9. The usefulness of myoglobin radioimmunoassays to diagnose and monitor hereditary forms of muscular dystrophy linked to the X-chromosome and to identify its carriers

    International Nuclear Information System (INIS)

    Heim, L.

    1985-01-01

    A total of 376 children suffering from malignant muscular dystrophy (DMD), which is transmitted by recessive genes, were subjected to 478 radioimmunological tests for the presence of myoglobin (Mb) in the serum and found to be positive in 98% of the cases. There was a correlation between the Mb values and certain enzymes produced in the muscles, in particular CK and LDH, whereas no such link could be established regarding the age of the patients. The increases in the Mb values and related parameters seen in benign forms of muscular dystrophy failed to attain statistical significance, nor did the Mb values determined within the individual age groups permit any statistically relevant conclusions to be drawn as to the therapeutic success. Out of 58 proven carriers 73% were positive on the Mb tests, as compared to no more than 10% of the suspected carriers (the CK values remaining within normal limits). Among suspected juvenile carriers (sisters of DMD patients), increased Mb values were more frequent (25%) than increased CK values (12%). Within the group of suspected carriers there was a significant correlation between the increases in Mb and CK, which was absent in the proven carriers. One asset of radioimmunological tests to detect Mb in the serum is their superior sensitivity. They may yield valuable information in addition to that provided by muscle enzyme measurements, in particular in specific situations like those occurring during follow-up observations, in the assessment of drugs acting on muscular permeability and in the identification of carriers of either type of disease. (TRV) [de

  10. The unique genomic properties of sex-biased genes: Insights from avian microarray data

    Directory of Open Access Journals (Sweden)

    Webster Matthew T

    2008-03-01

    Full Text Available Abstract Background In order to develop a framework for the analysis of sex-biased genes, we present a characterization of microarray data comparing male and female gene expression in 18 day chicken embryos for brain, gonad, and heart tissue. Results From the 15982 significantly expressed coding regions that have been assigned to either the autosomes or the Z chromosome (12979 in brain, 13301 in gonad, and 12372 in heart, roughly 18% were significantly sex-biased in any one tissue, though only 4 gene targets were biased in all tissues. The gonad was the most sex-biased tissue, followed by the brain. Sex-biased autosomal genes tended to be expressed at lower levels and in fewer tissues than unbiased gene targets, and autosomal somatic sex-biased genes had more expression noise than similar unbiased genes. Sex-biased genes linked to the Z-chromosome showed reduced expression in females, but not in males, when compared to unbiased Z-linked genes, and sex-biased Z-linked genes were also expressed in fewer tissues than unbiased Z coding regions. Third position GC content, and codon usage bias showed some sex-biased effects, primarily for autosomal genes expressed in the gonad. Finally, there were several over-represented Gene Ontology terms in the sex-biased gene sets. Conclusion On the whole, this analysis suggests that sex-biased genes have unique genomic and organismal properties that delineate them from genes that are expressed equally in males and females.

  11. X-derived marker chromosome in patient with mosaic Turner syndrome and Dandy-Walker syndrome: a case report

    OpenAIRE

    Telepova, Alena S.; Romanenko, Svetlana A.; Lemskaya, Natalya A.; Maksimova, Yulia V.; Shorina, Asia R.; Yudkin, Dmitry V.

    2017-01-01

    Background Small supernumerary marker chromosomes can be derived from autosomes and sex chromosomes and can accompany chromosome pathologies, such as Turner syndrome. Case presentation Here, we present a case report of a patient with mosaic Turner syndrome and Dandy-Walker syndrome carrying a marker chromosome. We showed the presence of the marker chromosome in 33.8% of blood cells. FISH of the probe derived from the marker chromosome by microdissection revealed that it originated from the ce...

  12. Sex-biased gene expression during head development in a sexually dimorphic stalk-eyed fly.

    Directory of Open Access Journals (Sweden)

    Gerald S Wilkinson

    Full Text Available Stalk-eyed flies (family Diopsidae are a model system for studying sexual selection due to the elongated and sexually dimorphic eye-stalks found in many species. These flies are of additional interest because their X chromosome is derived largely from an autosomal arm in other flies. To identify candidate genes required for development of dimorphic eyestalks and investigate how sex-biased expression arose on the novel X, we compared gene expression between males and females using oligonucleotide microarrays and RNA from developing eyestalk tissue or adult heads in the dimorphic diopsid, Teleopsis dalmanni. Microarray analysis revealed sex-biased expression for 26% of 3,748 genes expressed in eye-antennal imaginal discs and concordant sex-biased expression for 86 genes in adult heads. Overall, 415 female-biased and 482 male-biased genes were associated with dimorphic eyestalk development but not differential expression in the adult head. Functional analysis revealed that male-biased genes are disproportionately associated with growth and mitochondrial function while female-biased genes are associated with cell differentiation and patterning or are novel transcripts. With regard to chromosomal effects, dosage compensation occurs by elevated expression of X-linked genes in males. Genes with female-biased expression were more common on the X and less common on autosomes than expected, while male-biased genes exhibited no chromosomal pattern. Rates of protein evolution were lower for female-biased genes but higher for genes that moved on or off the novel X chromosome. These findings cannot be due to meiotic sex chromosome inactivation or by constraints associated with dosage compensation. Instead, they could be consistent with sexual conflict in which female-biased genes on the novel X act primarily to reduce eyespan in females while other genes increase eyespan in both sexes. Additional information on sex-biased gene expression in other tissues and

  13. Genome-Wide Search Identifies 1.9 Mb from the Polar Bear Y Chromosome for Evolutionary Analyses.

    Science.gov (United States)

    Bidon, Tobias; Schreck, Nancy; Hailer, Frank; Nilsson, Maria A; Janke, Axel

    2015-05-27

    The male-inherited Y chromosome is the major haploid fraction of the mammalian genome, rendering Y-linked sequences an indispensable resource for evolutionary research. However, despite recent large-scale genome sequencing approaches, only a handful of Y chromosome sequences have been characterized to date, mainly in model organisms. Using polar bear (Ursus maritimus) genomes, we compare two different in silico approaches to identify Y-linked sequences: 1) Similarity to known Y-linked genes and 2) difference in the average read depth of autosomal versus sex chromosomal scaffolds. Specifically, we mapped available genomic sequencing short reads from a male and a female polar bear against the reference genome and identify 112 Y-chromosomal scaffolds with a combined length of 1.9 Mb. We verified the in silico findings for the longer polar bear scaffolds by male-specific in vitro amplification, demonstrating the reliability of the average read depth approach. The obtained Y chromosome sequences contain protein-coding sequences, single nucleotide polymorphisms, microsatellites, and transposable elements that are useful for evolutionary studies. A high-resolution phylogeny of the polar bear patriline shows two highly divergent Y chromosome lineages, obtained from analysis of the identified Y scaffolds in 12 previously published male polar bear genomes. Moreover, we find evidence of gene conversion among ZFX and ZFY sequences in the giant panda lineage and in the ancestor of ursine and tremarctine bears. Thus, the identification of Y-linked scaffold sequences from unordered genome sequences yields valuable data to infer phylogenomic and population-genomic patterns in bears. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  14. Genome-Wide Search Identifies 1.9 Mb from the Polar Bear Y Chromosome for Evolutionary Analyses

    Science.gov (United States)

    Bidon, Tobias; Schreck, Nancy; Hailer, Frank; Nilsson, Maria A.; Janke, Axel

    2015-01-01

    The male-inherited Y chromosome is the major haploid fraction of the mammalian genome, rendering Y-linked sequences an indispensable resource for evolutionary research. However, despite recent large-scale genome sequencing approaches, only a handful of Y chromosome sequences have been characterized to date, mainly in model organisms. Using polar bear (Ursus maritimus) genomes, we compare two different in silico approaches to identify Y-linked sequences: 1) Similarity to known Y-linked genes and 2) difference in the average read depth of autosomal versus sex chromosomal scaffolds. Specifically, we mapped available genomic sequencing short reads from a male and a female polar bear against the reference genome and identify 112 Y-chromosomal scaffolds with a combined length of 1.9 Mb. We verified the in silico findings for the longer polar bear scaffolds by male-specific in vitro amplification, demonstrating the reliability of the average read depth approach. The obtained Y chromosome sequences contain protein-coding sequences, single nucleotide polymorphisms, microsatellites, and transposable elements that are useful for evolutionary studies. A high-resolution phylogeny of the polar bear patriline shows two highly divergent Y chromosome lineages, obtained from analysis of the identified Y scaffolds in 12 previously published male polar bear genomes. Moreover, we find evidence of gene conversion among ZFX and ZFY sequences in the giant panda lineage and in the ancestor of ursine and tremarctine bears. Thus, the identification of Y-linked scaffold sequences from unordered genome sequences yields valuable data to infer phylogenomic and population-genomic patterns in bears. PMID:26019166

  15. Contrasting Patterns of Genomic Diversity Reveal Accelerated Genetic Drift but Reduced Directional Selection on X-Chromosome in Wild and Domestic Sheep Species.

    Science.gov (United States)

    Chen, Ze-Hui; Zhang, Min; Lv, Feng-Hua; Ren, Xue; Li, Wen-Rong; Liu, Ming-Jun; Nam, Kiwoong; Bruford, Michael W; Li, Meng-Hua

    2018-04-01

    Analyses of genomic diversity along the X chromosome and of its correlation with autosomal diversity can facilitate understanding of evolutionary forces in shaping sex-linked genomic architecture. Strong selective sweeps and accelerated genetic drift on the X-chromosome have been inferred in primates and other model species, but no such insight has yet been gained in domestic animals compared with their wild relatives. Here, we analyzed X-chromosome variability in a large ovine data set, including a BeadChip array for 943 ewes from the world's sheep populations and 110 whole genomes of wild and domestic sheep. Analyzing whole-genome sequences, we observed a substantially reduced X-to-autosome diversity ratio (∼0.6) compared with the value expected under a neutral model (0.75). In particular, one large X-linked segment (43.05-79.25 Mb) was found to show extremely low diversity, most likely due to a high density of coding genes, featuring highly conserved regions. In general, we observed higher nucleotide diversity on the autosomes, but a flat diversity gradient in X-linked segments, as a function of increasing distance from the nearest genes, leading to a decreased X: autosome (X/A) diversity ratio and contrasting to the positive correlation detected in primates and other model animals. Our evidence suggests that accelerated genetic drift but reduced directional selection on X chromosome, as well as sex-biased demographic events, explain low X-chromosome diversity in sheep species. The distinct patterns of X-linked and X/A diversity we observed between Middle Eastern and non-Middle Eastern sheep populations can be explained by multiple migrations, selection, and admixture during the domestic sheep's recent postdomestication demographic expansion, coupled with natural selection for adaptation to new environments. In addition, we identify important novel genes involved in abnormal behavioral phenotypes, metabolism, and immunity, under selection on the sheep X-chromosome.

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

    Science.gov (United States)

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

    2012-07-01

    Differentiation of the bipotential gonad into testis is initiated by the Y chromosome-linked gene SRY (Sex-determining Region Y) through upregulation of its autosomal direct target gene SOX9 (Sry-related HMG box-containing gene 9). Sequence and chromosome homology studies have shown that SRY most probably evolved from SOX3, which in humans is located at Xq27.1. Mutations causing SOX3 loss-of-function do not affect the sex determination in mice or humans. However, transgenic mouse studies have shown that ectopic expression of Sox3 in the bipotential gonad results in upregulation of Sox9, resulting in testicular induction and XX male sex reversal. However, the mechanism by which these rearrangements cause sex reversal and the frequency with which they are associated with disorders of sex development remains unclear. Rearrangements of the SOX3 locus were identified recently in three cases of human XX male sex reversal. We report on a case of XX male sex reversal associated with a novel de novo duplication of the SOX3 gene. These data provide additional evidence that SOX3 gain-of-function in the XX bipotential gonad causes XX male sex reversal and further support the hypothesis that SOX3 is the evolutionary antecedent of SRY. Copyright © 2012 Wiley Periodicals, Inc.

  17. Identification of SOX3 as an XX male sex reversal gene in mice and humans.

    Science.gov (United States)

    Sutton, Edwina; Hughes, James; White, Stefan; Sekido, Ryohei; Tan, Jacqueline; Arboleda, Valerie; Rogers, Nicholas; Knower, Kevin; Rowley, Lynn; Eyre, Helen; Rizzoti, Karine; McAninch, Dale; Goncalves, Joao; Slee, Jennie; Turbitt, Erin; Bruno, Damien; Bengtsson, Henrik; Harley, Vincent; Vilain, Eric; Sinclair, Andrew; Lovell-Badge, Robin; Thomas, Paul

    2011-01-01

    Sex in mammals is genetically determined and is defined at the cellular level by sex chromosome complement (XY males and XX females). The Y chromosome-linked gene sex-determining region Y (SRY) is believed to be the master initiator of male sex determination in almost all eutherian and metatherian mammals, functioning to upregulate expression of its direct target gene Sry-related HMG box-containing gene 9 (SOX9). Data suggest that SRY evolved from SOX3, although there is no direct functional evidence to support this hypothesis. Indeed, loss-of-function mutations in SOX3 do not affect sex determination in mice or humans. To further investigate Sox3 function in vivo, we generated transgenic mice overexpressing Sox3. Here, we report that in one of these transgenic lines, Sox3 was ectopically expressed in the bipotential gonad and that this led to frequent complete XX male sex reversal. Further analysis indicated that Sox3 induced testis differentiation in this particular line of mice by upregulating expression of Sox9 via a similar mechanism to Sry. Importantly, we also identified genomic rearrangements within the SOX3 regulatory region in three patients with XX male sex reversal. Together, these data suggest that SOX3 and SRY are functionally interchangeable in sex determination and support the notion that SRY evolved from SOX3 via a regulatory mutation that led to its de novo expression in the early gonad.

  18. Effect of Sex-linked Feathering Genes on Body Weight, Age At Sexual Maturity, Feed Intake and Subsequent Laying Performance of Baladi Chickens

    Directory of Open Access Journals (Sweden)

    A. AI-Sobayel

    1997-01-01

    Full Text Available A total of 320 twenty week-old slow and rapid feathering Saudi Arabian Baladi pullers were used to assess the effect of sex-linked feathering genes on body weight, age at sexual maturity, feed intake and subsequent laying performance. Similar numbers of rapid feathering Leghorns pullets were included in the study for the purpose of comparison. The experimental birds of each genotypic group were randomly divided into four replicates and subjected to standard management practices. Slow feathering Baladi pullers had higher (P<0.05 adult body weight, rate of mortality, and feed intake and a similar age at sexual maturity but showed lower (P< 0.05 hen-day, and hen-housed egg production and feed conversion compared with rapid feathering Baladi pullets. Rapid feathering Leghorns had higher (P<0.05 adult body weight. age at sexual maturity, hen-day egg production, rate of mortality and feed intake and lower feed intake/kg eggs than rapid and slow feathering Baladi. However, rapid feathering Baladi and Leghorns had similar hen-housed egg production and feed intake per dozen eggs and had better (l’<0.05' performance than slow feathering Baladi.

  19. Manifestaciones clínicas de la retinosis pigmentaria recesiva ligada al sexo en una portadora Clinical manifestations of recessive retinitis pigmentosa linked to sex in a carrier

    Directory of Open Access Journals (Sweden)

    Elisa Dyce Gordon

    2001-06-01

    Full Text Available Se presenta el caso de una portadora del gen mutante causante de la retinosis pigmentaria con herencia recesiva ligada al sexo con un cuadro clínico típico de la enfermedad, de inicio tardío y marcada asimetría de las manifestaciones oftalmológicas entre ambos ojos. Se expone la hipótesis de Lyon para explicar la ocurrencia de este hecho. Se concluye que las heterocigotas pueden manifestarse clínicamente al igual que los varones hemicigotos, por lo que a todas se les debe realizar estudio oftalmológico minucioso para confirmar el estado de portadora, así como para iniciar tratamiento adecuado, de ser necesario.The case of a carrier of the mutant gene causing retinitis pigmentosa with recessive heredity linked to sex with a typical clinical picture of late onset disease and marked assimetry of ophthalmological manifestations between both eyes is presented. Lyon's hypothesis is used to explain the occurrence of this event. It is concluded that heterozygote females may have the same clinical manifestations as hemizigote males. That's why, an ophthalmologic thorough study should be conducted to confirm the state of the carrier as well as to initiate an adequate treatment, if necessary.

  20. Chromosomal characterization of the bonytongue Arapaima gigas (Osteoglossiformes: Arapaimidae

    Directory of Open Access Journals (Sweden)

    Debora Karla Marques

    Full Text Available The mitotic chromosomes of the pirarucu Arapaima gigas inhabiting the middle Araguaia River and collected in the municipality of Araguaiana (MT, Brazil were studied. The chromosomes were analyzed through Giemsa staining, C-banding, Ag-NOR staining and in situ hybridization using an 18S rRNA gene probe. The karyotype had 2n=56 comprising 14 biarmed and 14 uniarmed chromosome pairs in both sexes. No cytologically distinguishable sex chromosome was identified. A single NOR-bearing chromosome pair was detected by Ag-NOR staining and confirmed by 18S rDNA- FISH. Faint constitutive heterochromatin was C-banded in the centromeric region of some chromosomes.

  1. QTL list: sex1.2 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64750 Cucumis sativus Cucurbitaceae sex1.2 Number of female nodes on mainstem gynoecious (F) trait (sex...1.1), determinate (de) trait (sex1.2) ... LG_01 ... 25.7 7.3 ... 10.1007/s00122-003-1277-1 12827247

  2. QTL list: sex6.1 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64751 Cucumis sativus Cucurbitaceae sex6.1 Number of female nodes on mainstem gynoecious (F) trait (sex...1.1), determinate (de) trait (sex1.2) ... LG_06 ... 63.8 5 ... 10.1007/s00122-003-1277-1 12827247

  3. QTL list: sex6.1 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64904 Cucumis sativus Cucurbitaceae sex6.1 Female flower ratio gynoecious (F) locus (sex...2.1), small spines (ss) locus (sex6.1) ... e7m18b LG_02 ... 92.6 4.47 ... 10.1007/s10681-008-9722-5 ...

  4. QTL list: sex2.1 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64906 Cucumis sativus Cucurbitaceae sex2.1 Female flower ratio gynoecious (F) locus (sex...2.1), small spines (ss) locus (sex6.1) ... CS15 LG_06 ... 35.3 6.56 ... 10.1007/s10681-008-9722-5 ...

  5. QTL list: sex1.1 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64749 Cucumis sativus Cucurbitaceae sex1.1 Number of female nodes on mainstem gynoecious (F) trait (sex...1.1), determinate (de) trait (sex1.2) ... LG_01 ... 1.5 13 ... 10.1007/s00122-003-1277-1 12827247

  6. QTL list: sex2.2 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64903 Cucumis sativus Cucurbitaceae sex2.2 Female flower ratio gynoecious (F) locus (sex...2.1), small spines (ss) locus (sex6.1) ... F LG_02 ... 10.5 84.44 ... 10.1007/s10681-008-9722-5 ...

  7. QTL list: sex2.1 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64905 Cucumis sativus Cucurbitaceae sex2.1 Female flower ratio gynoecious (F) locus (sex...2.1), small spines (ss) locus (sex6.1) ... e7m18b LG_02 ... 91.6 3.51 ... 10.1007/s10681-008-9722-5 ...

  8. QTL list: sex2.1 [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT64902 Cucumis sativus Cucurbitaceae sex2.1 Female flower ratio gynoecious (F) locus (sex...2.1), small spines (ss) locus (sex6.1) ... S94A1 LG_02 ... 9.2 72.94 ... 10.1007/s10681-008-9722-5 ...

  9. sex and Cannibalism

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 12. The Secret Sex Lives of Rotifers Sex - sex and Cannibalism. T Ramakrishna Rao. General Article Volume 5 Issue 12 December 2000 pp 41-47. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. X chromosome and suicide.

    Science.gov (United States)

    Fiori, L M; Zouk, H; Himmelman, C; Turecki, G

    2011-02-01

    Suicide completion rates are significantly higher in males than females in most societies. Although gender differences in suicide rates have been partially explained by environmental and behavioral factors, it is possible that genetic factors, through differential expression between genders, may also help explain gender moderation of suicide risk. This study investigated X-linked genes in suicide completers using a two-step strategy. We first took advantage of the genetic structure of the French-Canadian population and genotyped 722 unrelated French-Canadian male subjects, of whom 333 were suicide completers and 389 were non-suicide controls, using a panel of 37 microsatellite markers spanning the entire X chromosome. Nine haplotype windows and several individual markers were associated with suicide. Significant results aggregated primarily in two regions, one in the long arm and another in the short arm of chromosome X, limited by markers DXS8051 and DXS8102, and DXS1001 and DXS8106, respectively. The second stage of the study investigated differential brain expression of genes mapping to associated regions in Brodmann areas 8/9, 11, 44 and 46, in an independent sample of suicide completers and controls. Six genes within these regions, Rho GTPase-activating protein 6, adaptor-related protein complex 1 sigma 2 subunit, glycoprotein M6B, ribosomal protein S6 kinase 90  kDa polypeptide 3, spermidine/spermine N(1)-acetyltransferase 1 and THO complex 2, were found to be differentially expressed in suicide completers.

  11. Chromosomes of South American Bufonidae (Amphibia, Anura Chromosomes of South American Bufonidae (Amphibia, Anura

    Directory of Open Access Journals (Sweden)

    Brum Zorrilla N.

    1973-09-01

    Full Text Available Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.

  12. Forensic use of Y-chromosome DNA: a general overview

    NARCIS (Netherlands)

    M.H. Kayser (Manfred)

    2017-01-01

    textabstractThe male-specific part of the human Y chromosome is widely used in forensic DNA analysis, particularly in cases where standard autosomal DNA profiling is not informative. A Y-chromosomal gene fragment is applied for inferring the biological sex of a crime scene trace donor. Haplotypes

  13. Genetic and chromosomal effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The genetic and chromosomal effects of ionizing radiations deal with those effects in the descendants of the individuals irradiated. The information base concerning genetic and chromosomal injury to humans from radiation is less adequate than is the information base for cancer and leukemia. As a result, it is not possible to make the kinds of quantitative estimates that have been made for carcinogenesis in previous chapters of this book. The chapter includes a detailed explanation of various types of genetic injuries such as chromosomal diseases, x-linked diseases, autosomal dominant diseases, recessive diseases, and irregularly inherited diseases. Quantitative estimates of mutation rates and incidences are given based on atomic bomb survivors data

  14. Meiotic drive influences the outcome of sexually antagonistic selection at a linked locus.

    Science.gov (United States)

    Patten, M M

    2014-11-01

    Most meiotic drivers, such as the t-haplotype in Mus and the segregation distorter (SD) in Drosophila, act in a sex-specific manner, gaining a transmission advantage through one sex although suffering only the fitness costs associated with the driver in the other. Their inheritance is thus more likely through one of the two sexes, a property they share with sexually antagonistic alleles. Previous theory has shown that pairs of linked loci segregating for sexually antagonistic alleles are more likely to remain polymorphic and that linkage disequilibrium accrues between them. I probe this similarity between drive and sexual antagonism and examine the evolution of chromosomes experiencing these selection pressures simultaneously. Reminiscent of previous theory, I find that: the opportunity for polymorphism increases for a sexually antagonistic locus that is physically linked to a driving locus; the opportunity for polymorphism at a driving locus also increases when linked to a sexually antagonistic locus; and stable linkage disequilibrium accompanies any polymorphic equilibrium. Additionally, I find that drive at a linked locus favours the fixation of sexually antagonistic alleles that benefit the sex in which drive occurs. Further, I show that under certain conditions reduced recombination between these two loci is selectively favoured. These theoretical results provide clear, testable predictions about the nature of sexually antagonistic variation on driving chromosomes and have implications for the evolution of genomic architecture. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  15. Dysfunctional growth hormone receptor in a strain of sex-linked dwarf chicken: evidence for a mutation in the intracellular domain.

    Science.gov (United States)

    Agarwal, S K; Cogburn, L A; Burnside, J

    1994-09-01

    The sex-linked dwarf (dwdw) chicken represents a valuable animal model for studying GH insensitivity and the consequence of mutations in the GH receptor (GHR) gene. We have recently reported undetectable hepatic GH-binding activity and an aberrantly sized transcript in a strain of dwdw chickens obtained from Arbor Acre Farms, Inc. (Glastonbury, CT, USA). Southern blot analysis of the chicken GHR (cGHR) gene revealed a restriction-fragment length polymorphism in HindIII and EcoRI digests of genomic DNA in this strain of dwdw chicken. In order to localize the molecular mutation, we analysed the gene structure and determined the complete sequence of the 3' untranslated region (3' UTR) of the normal cGHR. With the use of this information, we located a large deletion in the 3' end of the cGHR gene of the Connecticut (CT) strain of dwdw chicken. This deletion (1773 bp) contained 27 highly conserved amino acids of the 3' end of the coding region, the in-frame stop codon, a less frequently used poly(A) signal that is normally found 445 bp downstream of the stop codon, and a large portion of the 3' UTR. Because of this deletion, 27 novel amino acids were substituted and the open reading frame was extended for an additional 26 amino acids before reaching the transcriptional termination site. The predicted amino acid sequence of the novel carboxyl-terminus of the dwdw cGHR is largely hydrophobic with a polylysine tail, whereas the carboxyl-terminus of the wild-type (DwDw) cGHR is composed of hydrophilic amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Limited phylogeographic signal in sex-linked and autosomal loci despite geographically, ecologically, and phenotypically concordant structure of mtDNA variation in the Holarctic avian genus Eremophila.

    Directory of Open Access Journals (Sweden)

    Sergei V Drovetski

    Full Text Available Phylogeographic studies of Holarctic birds are challenging because they involve vast geographic scale, complex glacial history, extensive phenotypic variation, and heterogeneous taxonomic treatment across countries, all of which require large sample sizes. Knowledge about the quality of phylogeographic information provided by different loci is crucial for study design. We use sequences of one mtDNA gene, one sex-linked intron, and one autosomal intron to elucidate large scale phylogeographic patterns in the Holarctic lark genus Eremophila. The mtDNA ND2 gene identified six geographically, ecologically, and phenotypically concordant clades in the Palearctic that diverged in the Early-Middle Pleistocene and suggested paraphyly of the horned lark (E. alpestris with respect to the Temminck's lark (E. bilopha. In the Nearctic, ND2 identified five subclades which diverged in the Late Pleistocene. They overlapped geographically and were not concordant phenotypically or ecologically. Nuclear alleles provided little information on geographic structuring of genetic variation in horned larks beyond supporting the monophyly of Eremophila and paraphyly of the horned lark. Multilocus species trees based on two nuclear or all three loci provided poor support for haplogroups identified by mtDNA. The node ages calculated using mtDNA were consistent with the available paleontological data, whereas individual nuclear loci and multilocus species trees appeared to underestimate node ages. We argue that mtDNA is capable of discovering independent evolutionary units within avian taxa and can provide a reasonable phylogeographic hypothesis when geographic scale, geologic history, and phenotypic variation in the study system are too complex for proposing reasonable a priori hypotheses required for multilocus methods. Finally, we suggest splitting the currently recognized horned lark into five Palearctic and one Nearctic species.

  17. Safe sex

    Science.gov (United States)

    ... sex; Sexually transmitted - safe sex; GC - safe sex; Gonorrhea - safe sex; Herpes - safe sex; HIV - safe sex; ... contact. STIs include: Chlamydia Genital herpes Genital warts Gonorrhea Hepatitis HIV HPV Syphilis STIs are also called ...

  18. Sexual dimorphism in white campion: deletion on the Y chromosome results in a floral asexual phenotype

    International Nuclear Information System (INIS)

    Farbos, I.; Veuskens, J.; Vyskot, B.; Oliveira, M.; Hinnisdaels, S.; Aghmir, A.; Mouras, A.; Negrutiu, I.

    1999-01-01

    White campion is a dioecious plant with heteromorphic X and Y sex chromosomes. In male plants, a filamentous structure replaces the pistil, while in female plants the stamens degenerate early in flower development. Asexual (asx) mutants, cumulating the two developmental defects that characterize the sexual dimorphism in this species, were produced by gamma ray irradiation of pollen and screening in the M1 generation. The mutants harbor a novel type of mutation affecting an early function in sporogenous/parietal cell differentiation within the anther. The function is called stamen-promoting function (SPF). The mutants are shown to result from interstitial deletions on the Y chromosome. We present evidence that such deletions tentatively cover the central domain on the (p)-arm of the Y chromosome (Y2 region). By comparing stamen development in wild-type female and asx mutant flowers we show that they share the same block in anther development, which results in the production of vestigial anthers. The data suggest that the SPF, a key function(s) controlling the sporogenous/parietal specialization in premeiotic anthers, is genuinely missing in females (XX constitution). We argue that this is the earliest function in the male program that is Y-linked and is likely responsible for ''male dimorphism'' (sexual dimorphism in the third floral whorl) in white campion. More generally, the reported results improve our knowledge of the structural and functional organization of the Y chromosome and favor the view that sex determination in this species results primarily from a trigger signal on the Y chromosome (Y1 region) that suppresses female development. The default state is therefore the ancestral hermaphroditic state

  19. Delimiting the origin of a B chromosome by FISH mapping, chromosome painting and DNA sequence analysis in Astyanax paranae (Teleostei, Characiformes.

    Directory of Open Access Journals (Sweden)

    Duílio M Z de A Silva

    Full Text Available Supernumerary (B chromosomes have been shown to contain a wide variety of repetitive sequences. For this reason, fluorescent in situ hybridisation (FISH is a useful tool for ascertaining the origin of these genomic elements, especially when combined with painting from microdissected B chromosomes. In order to investigate the origin of B chromosomes in the fish species Astyanax paranae, these two approaches were used along with PCR amplification of specific DNA sequences obtained from the B chromosomes and its comparison with those residing in the A chromosomes. Remarkably, chromosome painting with the one-arm metacentric B chromosome probe showed hybridization signals on entire B chromosome, while FISH mapping revealed the presence of H1 histone and 18S rDNA genes symmetrically placed in both arms of the B chromosome. These results support the hypothesis that the B chromosome of A. paranae is an isochromosome. Additionally, the chromosome pairs Nos. 2 or 23 are considered the possible B chromosome ancestors since both contain syntenic H1 and 18S rRNA sequences. The analysis of DNA sequence fragments of the histone and rRNA genes obtained from the microdissected B chromosomes showed high similarity with those obtained from 0B individuals, which supports the intraspecific origin of B chromosomes in A. paranae. Finally, the population hereby analysed showed a female-biased B chromosome presence suggesting that B chromosomes in this species could influence sex determinism.

  20. Genetic and physical maps around the sex-determining M-locus of the dioecious plant asparagus.

    Science.gov (United States)

    Telgmann-Rauber, Alexa; Jamsari, Ari; Kinney, Michael S; Pires, J Chris; Jung, Christian

    2007-09-01

    Asparagus officinalis L. is a dioecious plant. A region called the M-locus located on a pair of homomorphic sex chromosomes controls the sexual dimorphism in asparagus. The aim of this work was to clone the region determining sex in asparagus from its position in the genome. The structure of the region encompassing M should be investigated and compared to the sex-determining regions in other dioecious model species. To establish an improved basis for physical mapping, a high-resolution genetic map was enriched with AFLP markers closely linked to the target locus by carrying out a bulked segregant analysis. By screening a BAC library with AFLP- and STS-markers followed by chromosome walking, a physical map with eight contigs could be established. However, the gaps between the contigs could not be closed due to a plethora of repetitive elements. Surprisingly, two of the contigs on one side of the M-locus did not overlap although they have been established with two markers, which mapped in a distance as low as 0.25 cM flanking the sex locus. Thus, the clustering of the markers indicates a reduced recombination frequency within the M-region. On the opposite side of the M-locus, a contig was mapped in a distance of 0.38 cM. Four closely linked BAC clones were partially sequenced and 64 putative ORFs were identified. Interestingly, only 25% of the ORFs showed sequence similarity to known proteins and ESTs. In addition, an accumulation of repetitive sequences and a low gene density was revealed in the sex-determining region of asparagus. Molecular cytogenetic and sequence analysis of BACs flanking the M-locus indicate that the BACs contain highly repetitive sequences that localize to centromeric and pericentromeric locations on all asparagus chromosomes, which hindered the localization of the M-locus to the single pair of sex chromosomes. We speculate that dioecious Silene, papaya and Asparagus species may represent three stages in the evolution of XX, XY sex

  1. Fetal chromosome analysis: screening for chromosome disease?

    DEFF Research Database (Denmark)

    Philip, J; Tabor, Ann; Bang, J

    1983-01-01

    The aim of the study was to investigate the rationale of the current indications for fetal chromosome analysis. 5372 women had 5423 amniocentesis performed, this group constituting a consecutive sample at the chromosome laboratory, Rigshospitalet, Copenhagen from March 1973 to September 1980 (Group...... A + B). Pregnant women 35 years of age, women who previously had a chromosomally abnormal child, families with translocation carriers or other heritable chromosomal disease, families where the father was 50 years or more and women in families with a history of Down's syndrome (group A), were compared...... to women having amniocentesis, although considered not to have any increased risk of fetal chromosome abnormality (1390 pregnancies, group B). They were also compared with 750 consecutive pregnancies in women 25-34 years of age, in whom all heritable diseases were excluded (group C). The risk of unbalanced...

  2. Cytogenetic abnormality in man, wider implications of theories of sex chromatin origin.

    Science.gov (United States)

    MILES, C P

    1962-01-01

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

  3. Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content

    NARCIS (Netherlands)

    Hughes, Jennifer F.; Skaletsky, Helen; Pyntikova, Tatyana; Graves, Tina A.; van Daalen, Saskia K. M.; Minx, Patrick J.; Fulton, Robert S.; McGrath, Sean D.; Locke, Devin P.; Friedman, Cynthia; Trask, Barbara J.; Mardis, Elaine R.; Warren, Wesley C.; Repping, Sjoerd; Rozen, Steve; Wilson, Richard K.; Page, David C.

    2010-01-01

    The human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome(1,2). Little is known about the recent evolution of the Y chromosome because only

  4. Alcohols as discriminating agents for genetic sexing in the Mediterranean fruit fly, Ceratitis capitata (Wied.)

    International Nuclear Information System (INIS)

    Riva Francos, M.E.

    1990-01-01

    The locus of the alcohol dehydrogenase (ADH) has been used to develop a genetic sexing mechanism in the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann). Previous work (1982-1984) has led to the isolation of a translocation linking a null mutant of this locus to the Y chromosome of the males. This strain, T-128, together with others showing different ADH electrophoretic patterns, have been assayed for their resistance to alcohols, such as allyl-alcohol, pentynol, ethanol and 2-propanol. The strains carrying the T-128 translocation show a differential, sex dependent survival to some of these alcohols. Part of this work is still in progress. The mutagenic ethyl methanesulphate (EMS) is being used to induce new ADH null mutants using the strain T-128 as a marker. Several hundred females have been treated with 0.04% EMS and then outcrossed to T-128 males. Their progeny is put through selective larval medium (0.08% allyl-alcohol) and the surviving F 1 individuals and subsequent F 2 are being analysed. Population studies have shown that the genetic sexing strain, T-128, is a double translocation with complete linkage between the Adh N allele (chromosome 2), and the Y chromosome, and incomplete linkage of the Y with the wild type allele of the apricot eye locus (ap + ) of chromosome 4. (author). 40 refs, 4 figs, 12 tabs

  5. Chromosome painting in plants.

    NARCIS (Netherlands)

    Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

    2001-01-01

    The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in

  6. Chromosomal variation, macroevolution and possible parapatric speciation in Mepraia spinolai (Porter (Hemiptera: Reduviidae

    Directory of Open Access Journals (Sweden)

    Frias Daniel

    1998-01-01

    Full Text Available Mepraia spinolai is an endemic species in Chile that lives in wild and domestic habitats. It is the only species of the Reduviidae family that shows alate polymorphism; females are always wingless, but males can be found with and without wings. The M. spinolai karyotype consists of 10 pairs of autosomes and a complex sex determination system. Males from the northernmost regions I and II (latitude 18°-26° South are always winged (braquipterous and are X1X2Y, with a large Y chromosome. From region III to the metropolitan region (latitude 26°-33° South, males may be either winged or wingless but appear to be polymorphic for a small neo-Y chromosome, which may have originated by fracture of the large holocentric Y chromosome found in populations from farther north. Experimental crosses suggest that the genes for wings are linked in the Y chromosome and also that there are two cytologically indistinguishable types of neo-Y chromosomes. One form (Y1 bears a gene or genes for wings while the other (Y2 lacks such genes. Males that are X1X2Y1, X1X2Y1Y1 and X1X2Y1Y2 are winged, while the absence of Y1 (X1X2Y2 and X1X2Y2Y2 results in a wingless male. These chromosomes and morphological changes are correlated with a shift of the southern population into more arid habitats of the interior in the metropolitan region and region III.

  7. Analysis of recessive sex-linked lethal mutations in genetically different strains of Drosophila melanogaster ms and w irradiated in the five-kilometer zone of the Chernobyl meltdown

    International Nuclear Information System (INIS)

    Aslanyan, M.M.; Kim, A.I.; Magomedova, M.A.; Fatkulbayanova, N.L.

    1994-01-01

    The frequency of induced and spontaneous recessive sex-linked lethal mutations (RSLLM) in Drosophila melanogaster strains w and ms was estimated after their chronic irradiation in the five-kilometer zone of the Chernobyl' meltdown. The mutagenic effect of relatively low radiation doses was analyzed. In an experiment conducted in 1990, a significant increase in the RSLLM frequency was recorded, while, in 1991, no significant difference between the experiment and control was found

  8. The chicken Z chromosome is enriched for genes with preferential expression in ovarian somatic cells

    Czech Academy of Sciences Publication Activity Database

    Mořkovský, L.; Storchová, R.; Plachý, Jiří; Ivánek, Robert; Divina, Petr; Hejnar, Jiří

    2010-01-01

    Roč. 70, č. 2 (2010), s. 129-136 ISSN 0022-2844 Institutional research plan: CEZ:AV0Z50520514 Keywords : Z chromosome * meiotic sex chromosome inactivation * sex ual antagonisms Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.311, year: 2010

  9. Seed sexing revealed female bias in two Rumex species

    Directory of Open Access Journals (Sweden)

    Dagmara Kwolek

    2011-07-01

    Full Text Available Sex-ratio bias in seeds of dioecious Rumex species with sex chromosomes is an interesting and still unsettled issue. To resolve gender among seeds of R. acetosa and R. thyrsiflorus (two species with an XX/XY1Y2 sex chromosome system, this work applied a PCR-based method involving DNA markers located on Y chromosomes. Both species showed female-biased primary sex ratios, with female bias greater in R. acetosa than in R. thyrsiflorus. The observed predominance of female seeds is consistent with the view that the female biased sex ratios in Rumex are conditioned not only postzygotically but also prezygotically.

  10. SHBG (Sex Hormone Binding Globulin)

    Science.gov (United States)

    ... Links Patient Resources For Health Professionals Subscribe Search Sex Hormone Binding Globulin (SHBG) Send Us Your Feedback ... As Testosterone-estrogen Binding Globulin TeBG Formal Name Sex Hormone Binding Globulin This article was last reviewed ...

  11. Manifestation of x-radiation induced sex-linked recessive lethal mutation impairing the development of imaginal disks and gonads in Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Abeleva, Eh.A.; Ivanov, A.I.

    1982-01-01

    A study was made of Drosophila melanogaster mutations impairing the development of imaginal disks. The state of gonads in these mutants was not studied. Using X-radiation a lethal mutation in X chromosome was obtained that induced degeneration of imaginal disks at the 3d stage of larva development. The gonads of the mutants at this stage of development vary in size. The transplantation tests showed that the mutation manifests itself in both the imaginal disks and the gonads

  12. A Chromosome-Scale Assembly of the Bactrocera cucurbitae Genome Provides Insight to the Genetic Basis of white pupae

    Directory of Open Access Journals (Sweden)

    Sheina B. Sim

    2017-06-01

    Full Text Available Genetic sexing strains (GSS used in sterile insect technique (SIT programs are textbook examples of how classical Mendelian genetics can be directly implemented in the management of agricultural insect pests. Although the foundation of traditionally developed GSS are single locus, autosomal recessive traits, their genetic basis are largely unknown. With the advent of modern genomic techniques, the genetic basis of sexing traits in GSS can now be further investigated. This study is the first of its kind to integrate traditional genetic techniques with emerging genomics to characterize a GSS using the tephritid fruit fly pest Bactrocera cucurbitae as a model. These techniques include whole-genome sequencing, the development of a mapping population and linkage map, and quantitative trait analysis. The experiment designed to map the genetic sexing trait in B. cucurbitae, white pupae (wp, also enabled the generation of a chromosome-scale genome assembly by integrating the linkage map with the assembly. Quantitative trait loci analysis revealed SNP loci near position 42 MB on chromosome 3 to be tightly linked to wp. Gene annotation and synteny analysis show a near perfect relationship between chromosomes in B. cucurbitae and Muller elements A–E in Drosophila melanogaster. This chromosome-scale genome assembly is complete, has high contiguity, was generated using a minimal input DNA, and will be used to further characterize the genetic mechanisms underlying wp. Knowledge of the genetic basis of genetic sexing traits can be used to improve SIT in this species and expand it to other economically important Diptera.

  13. Expansion of GA Dinucleotide Repeats Increases the Density of CLAMP Binding Sites on the X-Chromosome to Promote Drosophila Dosage Compensation.

    Directory of Open Access Journals (Sweden)

    Guray Kuzu

    2016-07-01

    Full Text Available Dosage compensation is an essential process that equalizes transcript levels of X-linked genes between sexes by forming a domain of coordinated gene expression. Throughout the evolution of Diptera, many different X-chromosomes acquired the ability to be dosage compensated. Once each newly evolved X-chromosome is targeted for dosage compensation in XY males, its active genes are upregulated two-fold to equalize gene expression with XX females. In Drosophila melanogaster, the CLAMP zinc finger protein links the dosage compensation complex to the X-chromosome. However, the mechanism for X-chromosome identification has remained unknown. Here, we combine biochemical, genomic and evolutionary approaches to reveal that expansion of GA-dinucleotide repeats likely accumulated on the X-chromosome over evolutionary time to increase the density of CLAMP binding sites, thereby driving the evolution of dosage compensation. Overall, we present new insight into how subtle changes in genomic architecture, such as expansions of a simple sequence repeat, promote the evolution of coordinated gene expression.

  14. Single cell Hi-C reveals cell-to-cell variability in chromosome structure

    Science.gov (United States)

    Schoenfelder, Stefan; Yaffe, Eitan; Dean, Wendy; Laue, Ernest D.; Tanay, Amos; Fraser, Peter

    2013-01-01

    Large-scale chromosome structure and spatial nuclear arrangement have been linked to control of gene expression and DNA replication and repair. Genomic techniques based on chromosome conformation capture assess contacts for millions of loci simultaneously, but do so by averaging chromosome conformations from millions of nuclei. Here we introduce single cell Hi-C, combined with genome-wide statistical analysis and structural modeling of single copy X chromosomes, to show that individual chromosomes maintain domain organisation at the megabase scale, but show variable cell-to-cell chromosome territory structures at larger scales. Despite this structural stochasticity, localisation of active gene domains to boundaries of territories is a hallmark of chromosomal conformation. Single cell Hi-C data bridge current gaps between genomics and microscopy studies of chromosomes, demonstrating how modular organisation underlies dynamic chromosome structure, and how this structure is probabilistically linked with genome activity patterns. PMID:24067610

  15. Sex determination mechanisms in the Calliphoridae (blow flies).

    Science.gov (United States)

    Scott, M J; Pimsler, M L; Tarone, A M

    2014-01-01

    The Calliphoridae or blow flies are a family of insects that occupy diverse habitats and perform important ecological roles, particularly the decomposition of animal remains. Some Calliphoridae species are also important in the forensic sciences, in agriculture (e.g. as livestock pests) and in medicine (e.g. maggot therapy). Calliphoridae provide striking examples in support of the hypothesis that sex determination regulatory gene hierarchies evolve in the reverse order, with the gene at the top being the most recently added. Unlike the model fly Drosophila melanogaster, where sex is determined by the number of X chromosomes, in the Australian sheep blow fly (Lucilia cuprina) sex is determined by a Y-linked male-determining gene (M). A different regulatory system appears to operate in the hairy maggot blow fly (Chrysomya rufifacies) where the maternal genotype determines sex. It is hypothesized that females heterozygous for a dominant female-determining factor (F/f) produce only female offspring and homozygous f/f females produce only sons. The bottom of the regulatory hierarchy appears to be the same in D. melanogaster and L. cuprina, with sex-specific splicing of doublesex transcripts being controlled by the female-specific Transformer (TRA) protein. We discuss a model that has been proposed for how tra transcripts are sex-specifically spliced in calliphorids, which is very different from D. melanogaster. © 2013 S. Karger AG, Basel.

  16. Chromosomal location and gene paucity of the male specific region on papaya Y chromosome

    Czech Academy of Sciences Publication Activity Database

    Yu, Q.; Hou, S.; Hobza, Roman; Feltus, F.A.; Wang, X.; Jin, W.; Skelton, R.L.; Blas, A.; Lemke, C.; Saw, J.H.; Moore, P.H.; Alam, M.; Jiang, J.; Paterson, A.H.; Vyskot, Boris; Ming, R.

    2007-01-01

    Roč. 278, č. 2 (2007), s. 177-185 ISSN 1617-4615 R&D Projects: GA ČR(CZ) GA521/06/0056 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Carica papaya * repetitive sequences * sex chromosome Subject RIV: BO - Biophysics Impact factor: 2.978, year: 2007

  17. Conservation of chromosomes syntenic with avian autosomes in squamate reptiles revealed by comparative chromosome painting

    Czech Academy of Sciences Publication Activity Database

    Pokorná, Martina; Giovannotti, M.; Kratochvíl, L.; Caputo, V.; Olmo, E.; Ferguson-Smith, M. A.; Rens, W.

    2012-01-01

    Roč. 121, č. 4 (2012), s. 409-418 ISSN 0009-5915 R&D Projects: GA ČR GAP506/10/0718 Institutional support: RVO:67985904 Keywords : sex-chromosomes * evolution * genome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.340, year: 2012

  18. Human male infertility, the Y chromosome, and dinosaur extinction

    Directory of Open Access Journals (Sweden)

    Sherman J. Silber

    2011-06-01

    Our studies of the Y chromosome and male infertility suggest that the default mechanism for determining the sex of offspring is the temperature of egg incubation, and that genetic sex determination (based on sex chromosomes like X and Y has evolved many times over and over again in different ways, in different genera, as a more foolproof method than temperature variation of assuring a balanced sex ratio in offspring. The absence of such a genetic sex determining mechanism in dinosaurs may have led to a skewed sex ratio when global temperature dramatically changed 65,000,000 years ago, resulting in a preponderance of males, and consequentially a rapid decline in population.

  19. Two new pupal sexing strains in the Mediterranean fruit fly, Ceratitis capitata (Wied.)

    International Nuclear Information System (INIS)

    Zapater, M.

    1990-01-01

    A genetic sexing system in the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann), is urgently required in order to reduce the costs of mass rearing and to prevent punctures in fruit made by the ovipositors of sterilized females. Two genetic sexing strains, T(Y,5)122; T:Y(wp), white pupae, and T(Y,3,5)11; T:Y(dp + wp + ), were isolated and studied in connection with their possible use in a mass rearing programme. Both strains have males emerging from wild type brown pupae and females emerging from mutant pupae; they are stable up to generation 22. The strain T(Y,5)122 has a translocation linking the Y chromosome with the autosome carrying the wp locus. The strain T(Y,3,5)11 has a translocation linking the Y chromosome and the two chromosomes carrying the wp and the dp loci. The egg fertility of the strain T(Y,5)122 was 52% and that of T(Y,3,5)11 was 48%. Larval survival of the latter line was 79%. The technical advantages of these strains was discussed in this paper. The strain T(Y,4)116; T:Y(ap + ), apricot eye, is characterized by wild type males and apricot eye females, as well as apricot eye sterile males. A model explaining the appearance of these ap males is proposed. Isolation and preliminary fertility studies of six sex linked multiple translocations are presented. Each of these strains has three translocations involving the chromosomes Y, 3, 4 and 5. (author). 13 refs, 4 tabs

  20. Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae)

    Science.gov (United States)

    Suárez, Pablo; Boeris, Juan M.; Blasco-Zúñiga, Ailin; Barbero, Gastón; Gomes, Anderson; Gazoni, Thiago; Costa, William; Nagamachi, Cleusa Y.; Rivera, Miryan; Parise-Maltempi, Patricia P.; Wiley, John E.; Pieczarka, Julio C.; Haddad, Celio F. B.; Faivovich, Julián; Baldo, Diego

    2018-01-01

    The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini. PMID:29444174

  1. Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae.

    Directory of Open Access Journals (Sweden)

    Juan M Ferro

    Full Text Available The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46 and H. alytolylax (FN = 38, with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p, H. palmeri (4q, and H. larinopygion (1p. Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns for their impact on the taxonomy and karyotype evolution in Cophomantini.

  2. Chromosomal Evolution in Chiroptera.

    Science.gov (United States)

    Sotero-Caio, Cibele G; Baker, Robert J; Volleth, Marianne

    2017-10-13

    Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62). As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within distinct bat lineages (especially Phyllostomidae, Hipposideridae and Rhinolophidae), focusing on two perspectives: evolution of genome architecture, modes of chromosomal evolution, and the use of chromosome data to resolve taxonomic problems.

  3. Chromosomal Evolution in Chiroptera

    Directory of Open Access Journals (Sweden)

    Cibele G. Sotero-Caio

    2017-10-01

    Full Text Available Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62. As with other mammalian orders, Chiroptera is characterized by clades with low, moderate and extreme chromosomal change. In this article, we will discuss trends of karyotypic evolution within distinct bat lineages (especially Phyllostomidae, Hipposideridae and Rhinolophidae, focusing on two perspectives: evolution of genome architecture, modes of chromosomal evolution, and the use of chromosome data to resolve taxonomic problems.

  4. A genetic polymorphism in the sex-linked ATP5A1 gene is associated with individual fitness in Ovenbirds (Seiurus aurocapilla)

    Science.gov (United States)

    Judith D. Toms; Lori S. Eggert; Wayne J. Arendt; John Faaborg

    2012-01-01

    While testing genetic sexing techniques in Ovenbirds (Seiurus aurocapilla),we found a genetic polymorphism in the ATP5A1 gene in 38% of individuals. The Z ' allele included changes in both intronic and exonic portions of the sequenced region, but there was no evidence that this changed the resulting ATP synthase product. Males that had one or more copies of...

  5. Chromosomes and their meiotic behaviour in two species of Dieuches Dohrn, 1860 (Heteroptera: Lygaeidae: Rhyparochromini

    Directory of Open Access Journals (Sweden)

    Harbhajan Kaur

    2009-08-01

    Full Text Available The Lygaeidae (Heteroptera are a large and diverse family in which the male diploid chromosomal complement ranges from 10 to 30. Diploid numbers of 14 and 16 are taken as two modal numbers of the family. The Rhyparochrominae, one of the largest subfamilies of the Lygaeidae, are known to be heterogeneous both cytologically and morphologically. Available data on the tribe Rhyparochromini reveal that all species are characterized by the presence of a pair of microchromosomes (m-chromosomes and have an XY/XX (♂/♀ sex chromosome determining system. Dieuches coloratus (Distant, 1909 and D. insignis (Distant, 1918 belonging to Rhyparochromini, have 2n=14=10A+2m+XY and 2n=12=8A+2m+XY respectively. Both the species a