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Results for “XY chromosomes”

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At least 19 recordsLinked to original sources
PubMed1978

Gonadal dysgenesis in a phenotypic female with an XY chromosomal constitution.

A phenotypic female with an XY karyotype and pure gonadal dysgenesis is described. Bilateral streak gonads may be found in patients with features of Turner's syndrome and also in phenotypic females without the somatic abnormalities described in Turner's syndrome. Mixed gonadal dysgenesis refers to the presence of a unilateral streak gonad and contralateral testis in a phenotypic female. Dysgenetic gonads are more liable to undergo malignant change, especially in patients with an XY karyotype, and in those with mixed gonadal dysgenesis. Laparotomy and removal of the dysgenetic gonads is indicated in patients with an XY karyotype. If a 46,XX chromosomal pattern is present, the malignant potential is probably less, but laparotomy is still indicated to enable a prognosis to be given regarding fertility.

Adult↗
PubMed1979

Meiotic studies of translocations causing male sterility in the mouse. II. Double heterozygotes for Robertsonian translocations.

Unusual meiotic behavior of the XY chromosome pair was observed in sterile male mice doubly heterozygous for two Robertsonian translocations, Rb(16.17)7Bnr and Rb(8.17)1Iem. Nonrandom association between the X chromosome and the translocation configuration, ascertained from the frequencies of relevant C-band contacts, was found in 9 of 10 sterile males. Besides the nonrandom association, the XY chromosomes showed signs of impaired condensation, as judged by measurement of their lengths at diakinesis/MI of the first meiotic division. In contrast, neither nonrandom contact nor decondensation of the XY chromosomes pair was found in fertile males heterozygous for a single Robertsonian translocation, Rb1Iem or Rb7Bnr. The present observations lend indirect support to the working hypothesis advanced previously, the assumption that interference with X-chromosome inactivation is a possible cause of spermatogenic breakdown in carriers of various male-sterile chromosomal transloations. Alternative explanations of the available data, which cannot be ruled out, are briefly discussed.

Animals↗
PubMed1979

Testicular regression syndrome.

Recently, the testicular regression syndrome has been reported as being representative of a clinical range of XY agonadal persons. A patient with aberrant fetal sexual development is described. Of particular interest is that all of the tissues examined--the rudimentary uterine horn and the 2 fallopian tubes--displayed an XY chromosome complement. Correlation was made between the known temporal events of embryogenesis of the testes and the apparent time of regression of the testes. In this patient, the insult to testicular development, with subsequent testicular regression, occurred between 48 and 60 days after fertilization. This review supports the previously reported thesis that in certain XY persons the testes are irreparably damaged at a critical stage in fetal development, and that this critical stage is represented by a range of abnormalities of genital development. Possible causes and simplified nomenclature for such gonadal damage are presented.

Adult↗
PubMed1979

The Laurence-Moon-Bardet-Biedl syndrome: unresponsiveness to the action of testosterone, a possible mechanism.

The pathogenesis of hypogonadism and hypogenitalism was investigated in a male patient with the complete form of the Laurence-Moon-Bardet-Biedl syndrome. Synthetic gonadotropin-releasing hormone induced an increase in serum luteinizing hormone levels from 16.5 mIU/ml to 19.3 mIU/ml and in follicle-stimulating hormone levels from 18.5 mIU/ml to 25.9 mIU/ml. Serum testosterone levels were normal and did not rise after stimulation with human chorionic gonadotropin. The administration of thyrotropin-releasing hormone resulted in an increase in serum thyrotropin levels from 9.0 microU/ml to 12.0 microU/ml. Serum testoterone/estradiol-binding globulin, adrenocorticotropic hormone, and T3 resin uptake were normal. Serum cortisol showed a normal diurnal variation. The sex chromatin test was negative and the karyotupe revealed a 46,XY chromosome pattern. On biopsy, the left testis lacked germinal cells and the right testis showed spermatogenic arrest. Signs of hypogonadism and hypogenitalism persisted after 11 months of testosterone treatment. In this patient the target-organ unresponsiveness resulted in hypogenitalism and hypogonadism.

Adolescent↗
PubMed1979

Testicular function in post pubertal male pseudohermaphroditism.

Testicular endocrine function was studied in twelve post pubertal patients with male pseudohermaphroditism and 46 XY chromosomal constitution. Patients were divided into three groups, four subjects who became feminized during puberty, five who became masculinized during puberty and three who were castrated before puberty. Serum dehydroepiandrosterone, progesterone, 17-hydroxyprogesterone, androstendione, testosterone, dihydrotestosterone, LH and FSH were determined by radioimmunoassay. Patients of the first group had the clinical characteristics of testicular feminization secondary to absence of the androgen receptor. One of the five patients of the second group had deficient testosterone secretion but no enzymatic defect could be demonstrated. One of the subjects castrated before puberty had a deficiency in 17,20-desmolase. Therefore, evidence of a failure of the fetal testes could be found in only two of the twelve patients studied.

Adolescent↗
PubMed1978

Anorchia and persistent Müllerian duct: a variant of the embryonic testicular regression syndrome.

A 20-yr-old phenotypical male with a 46, XY chromosome complement, a hernia uteri inguinale, and bilateral anorchia was studied. Eunochoidal body proportions, infantile type of male external genitalia with empty scrotum, underdeveloped sexual characteristics, and delayed bone age suggested the existence of inadequate testicular function. Extremely low levels of circulating testosterone and a lack of response to hCG stimulation was found. Persistently elevated blood levels of LH and FSH with an adequate pituitary response to an iv bolus of synthetic LRH was demonstrated, thus indicating inadequate endocrine gonadal function as well as functional integrity of the hypothalamic-pituitary unit. At the time of an inguinal hernioplasty, a small but well developed uterus was removed. No gonads were found within the true pelvis, inguinal canals, or along the anatomical pathways of testicular descent. A cord-like structure found in the left inguinal canal contained only fibrous tissue without gonadal elements. It is proposed that the occurrence of two altered events during embryogenesis, failure of Müllerian duct regression and late testicular regression, may explain the underlying defect in this unusual abnormality of sexual differentiation.

Adult↗
PubMed1975

A patient with congenital anomalies and a deletion of the long arm of the long arm of chromosome 4 [46,XY,del(4)(q31)].

This paper describes the clinical symptoms and cytogenetic findings in a patient previously described in a doctoral thesis (van Kempen, 1969). The patient is a boy with multiple congenital anomalies and a deletion of the long arm of chromosome 4. A recent Giemsa banding study showed absence of the terminal G-band, as was found in the patient described by Golbus et al (1973). The symptoms and other data on the three patients known to have a deletion of the long arm of chromosome 4 are presented to facillitate comparison of these cases. However, the number of cases so far on record is too small to warrant conclusions on the basis of this comparison.

Abnormalities, Multiple↗
PubMed1978

46,XY pure gonadal dysgenesis with non-fluorescent Y chromosome.

A 46,XY karyotype with a non-fluorescent Y chromosome was found in an infantile girl aged 16 with primary amenorrhea. Identification of the Y chromosome was made by different staining techniques and a photometric scanning method. The histology of the streak gonad also indicated the Y character of the chromosome. The authors' interpretation is a 46,XY pure gonadal dysgenesis with a non-fluorescent Y chromosome.

Adolescent↗
PubMed1978

Mitotic recombination in the heterochromatin of the sex chromosomes of Drosophila melanogaster.

The frequency of spontaneous and X-ray-induced mitotic recombination involving the Y chromosome has been studied in individuals with a marked Y chromosome arm and different XY compound chromosomes. The genotypes used include X chromosomes with different amounts of X heterochromatin and either or both arms of the Y chromosome attached to either side of the centromere. Individuals with two Y chromosomes have also been studied. The results show that the bulk of mitotic recombination takes place between homologous regions.

Animals↗
PubMed1979

Prader-Willi syndrome and chromosomal mosaicism 46,XY/47,XY,+mar in two cases.

Two cases of the Prader-Willi syndrome with 46,XY/47,XY,+mar are reported. The majority of Prader-Willi patients with chromosome abnormalities have either 15/15 translocations or mosaicism. Both of these aberrations presumably occur after fertilization. A possible relationship between high parental age and chromosome abnormalities in the Prader-Willi syndrome is discussed.

Child↗
PubMed1977

Sex determination in germ line chimeras of Drosophila melanogaster.

Of 55 flies developing from blastoderms which had received male or female pole cell transplants, 15 (7 females and 8 males) wer shown by progeny testing to be germ line chimeras. Since donor and host pole cells were genetically marked with contrasting X- or Y-linked alleles, the progeny testing scheme enabled the genotypic sex of the donor component undergoing gametogenesis to be identified as either the same as ('homosexual' chimeras) or opposite ('heterosexual' chimeras) that of the host. All seven of the female chimeras were identified as 'homosexual' chimeras carrying only chromosomally female XYX donor and XX host germ cells. Similarly, all eight males were shown to be 'homosexual' chimeras with chromosomally male XY donor and XY host germ cells. The chromosomal sex of the donor component undergoing gametogenesis was in every case the same as the phenotypic sex of the host. Since there is an equal probability of constructing either a 'homosexual' or a 'heterosexual' chimera during pole cell transplantation, the ability of pole cells to differentiate functional gametes in hosts of the opposite sex was tested 50% of the time even if sex reversal of these donor pole cells could not be demonstrated. Thus the absence of 'heterosexual' chimerism strongly supports the interpretation that the phenotypic sex of a germ cell in Drosophila is determined entirely by its own chromosome constitution, not by that of the gonadal mesoderm.

Animals↗
PubMed1978

Euploid somatic recombinants with two active X or XY (1)Y(I) chromosomes isolated from cultured male Indian Muntjac cells after HVJ virus fusion, and their use for gene assignment.

Four diploid somatic recombinants were isolated from hybrids either between or within two diploid cell lines of a male Indian muntjac after HVJ virus-mediated cell fusion. Both parental lines had a normal male karyotype, 7,X,Y1,Y2, in which the largest autosomal pair was heteromorphic with respect to the size of the secondary constriction (1h+/1h-), C bands, and nucleolar organizers. Of the four recombinants, three showed a 6,XX,1h+/1h+ or 1h+/1h- karyotype, the remaining one a 7,XY1Y2,1h+/1h+. No late-replicating X chromosome was found in the XX recombinants, although it was demonstrated in the natural XX line, suggesting the presence of two active X chromosomes in the former. The G6PD, PGK, and HPRT activities were proportional to the number of active X chromosomes present in all cell types examined, indicating their X-linkage, whereas the same level of activities obtained for LDH and 6PGD indicated their autosomal linkage.

Animals↗
PubMed2026

Chromosomal-level genome assembly of minute pirate bug Orius nagaii Yasunaga, 1993 (Hemiptera: Anthocoridae).

Species of the genus Orius, diminutive predatory insects that act as natural enemies of other arthropods, are frequently employed in agricultural pest management for controlling various pests, such as thrips, mites, aphids, whiteflies, etc. However, the scarcity of high-quality genomic resources for these predators hinders our comprehension of their population evolution and predation ecology. Consequently, we assembled and annotated a chromosomal-scale genome of Orius nagaii by collating PacBio and Illumina sequencing and Hi-C genomic analysis techniques. The final genome assembly size 152.62 Mb, with scaffold and contig N50 lengths of 11.53 and 2.39 Mb, respectively. It is organized into 12 pairs of autosomes and a pair of XY sex chromosomes. The quality assessment of the genomic data with BUSCO revealed a completeness of 98.5% (n = 1,367). Also, 11,917 protein-coding genes were discovered, with 94.28% of them having functional annotations. The high-quality genome of O. nagaii produced serves as a valuable resource for comprehending the interactions between predatory natural enemies and hosts, along with their evolutionary trajectories.

Animals↗