Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aberrations seen in chromosomes of human peripheral-blood lymphocytes, X-irradiated in vitro, have been analysed in three types of preparations, treated to give G-banding; R-banding; and G-banding followed by R-banding on the same cells. The data from cells subjected to both banding techniques reveals that 30 per cent of the sites of chromosome breakage are situated at he interfaces between dark- and - light-stained bands. The results of all the analyses show that approximately 30 per cent of all breaks were located in either the telomere (19-5 per cent) or centromere (11-3 per cent) regions. Chromosomes rich in R-band material were not preferentially damaged, but chromosomes 12, 15, and particularly 17, were involved in aberrations more frequently than would be expected on the basis of their length. No breaks were found on the Y chromosome in the 114 male cells analysed, but the X did not appear to be spared from damage either in the male cells analysed, but the X did not appear to be spared from damage either in the male cell or the 136 female cells analysed. G and/or R-banding enables a much more accurate analysis of aberrations than can be obtained from the use of conventional staining techniques, and with these methods, it is shown that the numbers of induced asymmetrical and symmetrical exchanges are similar.
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PMID:Identification with G and R banding of the position of breakage points induced in human chromosomes by in vitro x-irradiation. 5 12

The sex dimorphism for adult stature is compared in four Chilean populations which differ in their Amerindian ABO blood group composition. Statistical analysis revealed a significant association between sex dimorphism and Amerindian admixture in these populations. Assuming, on one hand, that sex chromosomes have an influence on adult stature and human growth and considering, on the other, that the four populations differ in their X and Y chromosome composition as a consequence of an asymmetrical inter-racial marriage practice, it is postulated that the observed association between sex dimorphism and Amerindian gene composition is a result of this peculiar mating structure.
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PMID:Sex dimorphism in adult stature in four Chilean populations. 74 41

A 10 10/12 years old virilized girl with the syndrome of asymmetrical gonadal differentiation is reported. The patient had a negative sex chromatin and positive Y chromatin (bright fluorescent body of Y chromosome) in the buccal smear and 45,X/46,XY karyotype in the peripheral blood lymphocytes. An exploratory laparotomy showed a small uterus, two Fallopian tubes, a tumoural testis on the right side and a streak on the left side. Pathological examination revealed the presence of gonadoblastoma in both gonads. The Y chromatin was identified on histological sections only on the side of the testis, and was absent on the streak and its gonadoblastoma's nests. The distribution of the different cell lines and the fluorescence of the Y chromosome is discussed in relation to gonadal differentiation and the occurrence of gonadoblastoma.
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PMID:Asymmetrical gonadal differentiation and gonadoblastoma. Clinical, cytogenetic and histological findings. Case report. 124 81

A total of 320 intersex patients with a Y chromosome were classified into four groups; (1) gonadal dysgenesis, (2) asymmetrical gonadal differentiation, (3) virilizing male hermaphroditism and (4) feminizing male hermaphroditism (testicular feminization syndrome). Of these 320 cases, 98 were from the files of The Johns Hopkins Hospital and the remainder from the literature. The incidence of tumors in relation to age and clinical classification was analyzed by computer. The results were plotted for each group. It was found that the percentage of tumors rose appreciably soon after the age of puberty in the first three groups, and it was concluded that the gonads were best removed before the age of puberty. In the case of testicular feminization patients, procrastination until the age of 25 could be considered, if one were willing to assume the risk of neoplasia of about 3.6 per cent until then.
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PMID:The age of occurrence of gonadal tumors in intersex patients with a Y chromosome. 124 71

Chinese hamster metaphase chromosomes were labeled by nick-translation, which involved pretreatment of metaphase chromosomes with low levels of DNase I followed by incubation with DNA polymerase I and radioactively labeled nucleotides. The labeled DNA was located on nuclease-hypersensitive regions of the chromosomes, as suggested by the following observations. (i) The labeled DNA was hypersensitive to the subsequent DNase I digestion. (ii) The labeled DNA contained no nucleosomes. DNA reassociation kinetic analysis suggested that the labeled DNA was enriched in repetitive DNA sequences. Base composition analyses showed that the labeled DNA was highly enriched in guanine and adenine residues, suggesting that the nick-translation reaction was asymmetrical and the strand enriched in purine was preferentially translated. Autoradiographic analysis revealed that the label was distributed on every chromosome, but there was a lower grain density on the Y chromosome, which is heterochromatic and exhibits a relatively low level of gene activity. The locations of silver grains on the Y chromosomes were generally consistent with that revealed by the in situ hybridization using [3H]cDNA synthesized from the total Chinese hamster messenger RNA. These observations suggest that a specific subset of genomic DNA on active chromatin is the preferred site of the nick-translation.
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PMID:Nick-translation of metaphase chromosomes: in vitro labeling of nuclease-hypersensitive regions in chromosomes. 385 36

Twenty-one cases of mixed gonadal dysgenesis referred at age 1 to 16 years are studied. External genitalia were in most cases of types III-IV, with a small penis and posterior hypospadias, asymmetrical genital folds containing an externalized testis on one side. The internal genitalia varied according to the degree of dysgenesis of the gonads, and included an uterus and/or a vagina in 18 among the 21 cases. A chromosomal mosaicism XO/XY or XX/XY was found in 11 patients, the other 10 having a normal 46 XY caryotype. Pubertal follow-up was obtained in 10 cases, and showed always a male sexual development, without possibility to exactly evaluate the function of the testis. Choosing the sex assignment is relatively easy in newborns or infants with mixed gonadal dysgenesis. It relies more on anatomy (size of corpora cavernosa, feasibility of urethroplasty or vaginoplasty) than on the results of hormonal measurements. The presence of an Y chromosome is not by itself an argument to choose the male sex. In most cases, the choice of the female sex is the easiest and relies on strong clinical arguments, but it leads unavoidably to suppress both the testis and the dysgenetic gonad.
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PMID:[Mixed gonadal dysgenesis. Apropos of a series of 21 cases]. 400 79

Individual spindle fibres in prometaphase spermatocytes of the cricket, Neocurtilla hexadactyla, were irradiated with an ultraviolet microbeam. The stretched heteromorphic bivalent (X2Y) contracted to about 75% of its pre-irradiation length after irradiation of either of its two oppositely directed spindle fibres (i.e., the X2 or Y spindle fibre). The X2Y bivalent also contracted after irradiation of the connection between the kinetochores of the univalent X1 chromosome and the Y chromosome but it did not contract after irradiation of autosomal spindle fibres or of the spindle fibre of the X1 univalent sex chromosome. The spindles sometimes shrank after irradiation, but contraction of the X2Y bivalent was independent of spindle shrinkage. The data strongly suggest that the oppositely directed forces on a bivalent are not independent. One reason is that the X2Y contractions were asymmetrical: during contraction one kinetochore remained fixed in position while the other kinetochore (facing the opposite pole) moved towards the equator. In 75% of the cases the stationary kinetochore was associated with the irradiated spindle fibre. Thus, we suggest that the irradiation of a spindle fibre produces a state analogous to rigor in the irradiated spindle fibre and, because of effects on the control system, produces relaxation of tension in the oppositely directed non-irradiated spindle fibre, so that the kinetochore associated with the non-irradiated spindle fibre moves towards the equator. These experiments have identified a control system that coordinates force production to opposite poles.
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PMID:Prometaphase forces towards opposite spindle poles are not independent: an on/off control system is identified by ultraviolet microbeam irradiations. 666 64

The entity includes the Turner syndrome, the pure gonadal dysgenesis (Swyer syndrome), the asymmetrical gonadal differentiation, and gonadal dysgenesis of some forms of trisomy. The necessity of prophylactic gonadectomy in all patients with Y chromosome is stressed because of a close association with the arising of tumors in the dysgenetic gonads. The requirements are described of a successful substitution with steroids.
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PMID:[Morphology of the genitals in gonadal dysgenesis]. 666 42

We earlier described three lines of sex-reversed XY female mice deleted for sequences believed close to the testes-determining gene (Sry) on the Y chromosome short arm (Yp). The original sex-reversed females appeared among the offspring of XY males that carried the Yp duplication Sxr on their X chromosome. Earlier cytogenetic observations had suggested that the deletions resulted from asymmetrical meiotic recombination between the Y and the homologous Sxr region, but no direct evidence for this hypothesis was available. We have now analyzed the offspring of XSxr/Y males carrying an evolutionarily divergent Mus musculus domesticus Y chromosome, which permits detection and characterization of such recombination events. This analysis has enabled the derivation of a recombination map of Yp and Sxr, also demonstrating the orientation of Yp with respect to the Y centromere. The mapping data have established that Rbm, the murine homologue of a gene family cloned from the human Y chromosome, lies between Sry and the centromere. Analysis of two additional XY female lines shows that asymmetrical Yp-Sxr recombination leading to XY female sex reversal results in deletion of Rbm sequences. The deletions bring Sry closer to Y centromere, consistent with the hypothesis that position-effect inactivation of Sry is the basis for the sex reversal.
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PMID:Y chromosome short arm-Sxr recombination in XSxr/Y males causes deletion of Rbm and XY female sex reversal. 747 93

An approach designed to map and generate mutations in the region of the short arm of the mouse Y chromosome, known to be involved in sex determination and spermatogenesis, is described. This relies on homologous Yp-Sxra pairing and asymmetrical exchange which can occur at meiosis in XY males carrying Sxra on their X chromosome. Such exchange potentially generates deficiencies and duplications of Yp or Sxra. Three fertile XY females were found out of about 450 XY offspring from XSxra/Y x XX crosses. In all three, despite evidence for deletion of Y chromosomal material, the Sry locus was intact. Each deletion involved a repeat sequence, Sx1, located at a distance from Sry. Since expression of Sry was affected these results suggest that long range position effects have disrupted Sry action.
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PMID:Deletion of Y chromosome sequences located outside the testis determining region can cause XY female sex reversal. 827 95


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