Sex-determining Region Y Gene Research Articles

A del(X)(p11) carrying SRY sequences in an infant with ambiguous genitalia

BackgroundSRY (sex-determining region, Y) is the gene responsible of gonadal differentiation in the male and it is essential for the regular development of male genitalia. Translocations involving the human sex chromosomes are rarely reported, however here we are reporting a very rare translocation of SRY gene to the q -arm of a deleted X chromosome. This finding was confirmed by cytogenetic, fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR).Case presentationA 7-month infant was clinically diagnosed as an intersex case, with a phallus, labia majora and minora, a blind vagina and a male urethra. Neither uterus nor testes was detected by Ultrasonography. G-banding of his chromosomes showed 46,X,del(X)(p11) and fluorescent in situ hybridization (FISH) analysis showed a very small piece from the Y chromosome translocated to the q-arm of the del(X). Polymerase chain reaction (PCR) analysis revealed the presence of material from the sex-determining region Y (SRY) gene.ConclusionIt is suggested that the phenotype of the patient was caused by activation of the deleted X chromosome with SRY translocation, which is responsible for gonadal differentiation.

Genetic Analysis of a Family with 46, XY “Female” Associated with Infertility

Genetic analysis of a family with 46, XY “female” associated with infertility was performed using the conventional G-banding and gene mutation screening. The karyotypes of the two female patients were 46, XY and those of their parents were normal. The mutation screenings in sex-determining region Y ( SRY) gene and androgen receptor ( AR) gene were carried out. No mutation has been found in the whole coding sequence of SRY gene. The mutation of codon 840 CGT (arginine) to CAT (histidine) of AR gene led to the infertility in the patients. The patients showed androgen insensitivity. The clinical phenotype of theirs presented more deleteriously than and different from the one reported before, though they had the same mutation of codon 840 CGT (arginine) to CAT (histidine) of AR gene, which was very different from the mutation of 840 CGT (arginine) to TGT (cysteine) at the same codon.

돼지 SRY와 ZF 유전자를 이용한 성판별 기법

A method for sex determination of pigs was examined using polymerase chain reaction(PCR). Sex determining region Y(SRY) gene encoded on Y chromosome plays a key role for primary male development. Zinc finger X-Y(ZFX-ZFY) gene, one of the X-V homology gene group was found on the X and Y chromosomes, respectively, We tested for molecular sexing by amplification patterns of SRY and ZF genes. Genomic DNAs from various resources including porcine hairs and semen collected from domestic pig breeds and native pigs was used for PCR assay of each gene. The amplified products for porcine SRY gene were yielded only in males but not in females. On the other hand, two differential patterns were observed in amplification of ZF gene reflecting the chromosomal dimorphism by a length polymorphism between X and Y chromosomes. Of both, a common band was detected in all individuals tested so that this band might be amplified from ZFX gene as a PCR template, but another is specific for males indicated that from ZFY. The result of PCR assay provides identical information to that from investigation of phenotypic genders of the pigs tested. We suggest that this PCR strategy to determine porcine sexes using comparison of the amplification patterns of the SRY gene specific for Y chromosome and the dimorphic ZF gene between X and Y chromosomes may be a rapid and precise method for discrimination of two sexes and applied to DNA analysis of small samples such as embryonic blastomere, semen, and hairs.

An Analysis of the Genetic Factors Involved in Testicular Descent in a Cohort of 14 Male Patients with Anorchia

Anorchia, or the "vanishing testis syndrome," is characterized by the absence of testis in a 46,XY individual with a male phenotype. The etiology is unknown; however, the familial occurrence of the disease and the association of this phenotype with 46,XY gonadal dysgenesis has led to the suggestion that genetic factors, which play a role in testicular determination, may be involved. Alternatively, exploratory laparoscopy has suggested that anorchia may be caused by a prenatal testicular vascular accident associated with torsion during testicular descent. We screened a cohort of 14 boys with bilateral anorchia for mutations in the Y chromosome-linked testis-determining gene SRY (sex-determining region, Y chromosome); in the gene necessary for correct testicular descent, INSL3; and in the gene of its receptor (LGR8). Mutations in the INSL3 gene and the LGR8 T222P mutation are known to cause cryptorchidism. We confirmed previous reports that mutations in the SRY gene are not associated with anorchia. Although a common polymorphism was identified in the INSL3 gene, no mutations were observed. The recurrent T222P mutation in the LGR8 gene was not found in any of the patients. These data show for the first time a lack of association between genetic factors necessary for correct testicular descent and anorchia.

On-Chip Nanoliter-Volume Multiplex TaqMan Polymerase Chain Reaction from A Single Copy Based on Counting Fluorescence Released Microchambers

A novel method for multiplex TaqMan PCR in nanoliter volumes on a highly integrated silicon microchamber array is described. Three different gene targets, related to beta-actin, sex-determining region Y (SRY), and Rhesus D (RhD) were amplified and detected simultaneously on the same chip by using three different types of human genomic DNA as the templates. The lack of cross-contamination and carryover was shown using alternate dispensing of mineral oil-coated microchambers containing template and those without template. To confirm the specificity of our system to beta-actin, SRY, and RhD genes, we employed the larger volume PCR samples to a commercial real-time PCR system, SmartCycler. The samples were cycled with the same sustaining temperatures as with the microchamber array. Instead of the conventional method of DNA quantification, counting the number of the fluorescence released microchambers in consequence to TaqMan PCR was employed to our chip. This simple method of observing the end point signal had provided a dynamic quantitative range. Stochastic amplification of 0.4 copies/reaction chamber was achieved. The microfabricated PCR chip demonstrated a rapid and highly sensitive response for simultaneous multiple-target detection, which is a promising step toward the development of a fully integrated device for the "lab-on-a-chip" DNA analysis.

Sertoli–stromal cell tumor of the ovary: Immunohistochemical, ultrastructural, and genetic studies

The Sertoli–stromal cell tumor (SSCT) of the ovary shows a histologic resemblance to developing or adult testes and is often associated with virilization caused by tumor-produced androgenic hormone. In spite of the unique manifestation of SSCT, detailed characteristics of this tumor are still obscure. The mechanism by which SSCT occurs has not yet been determined. Six SSCTs were studied immunohistochemically, ultrastructurally, and by polymerase chain reaction (PCR) for the presence of sex-determining region Y (SRY) gene and the X chromosome activation state. Immunohistochemically, Sertoli-like cells of SSCT were positive not only for α-inhibin but also low-molecular-weight cytokeratin. In control testes, the expression of α-inhibin and cytokeratin was limited to a Sertoli cell component and rete testis, respectively. Ultrastructurally, tumor cells composing hollow tubules had an elongated nucleus with deep indentation and annulate lamellae, which are characteristic structures of mature Sertoli cells. In addition, they had studded microvilli on the apical surface and frequent desmosomes, which are structures noted in the cells of rete testis. Histologically, tumor cells of hollow tubules sometimes pouted into the lumen, as did the cells of tubulae rete, entrance into rete testis from seminiferous tubules. All of these findings indicate that some tumor cells of a SSCT show simultaneous differentiation into both Sertoli cells and cells of rete testis. SRY gene was not detected in any cases, and the X chromosome activation pattern was the same as that of the female control. HUM PATHOL 32:796-802. Copyright © 2001 by W.B. Saunders Company

A novel dimorphism in the human SRY gene: usefulness in human migration studies.

A nucleotide polymorphism of C or T was detected at position 465 in the sex-determining region Y (SRY) gene. To evaluate the utility of this dimorphism in human population studies, the frequency and the frequency of the haplotype combined with the two polymorphic loci YAP and M9 were examined in a total of 130 unrelated Japanese and 130 unrelated German males. The T nucleotide was found in 24.6% (32/130) of the Japanese but not in any of the 130 German males. Accordingly, four of the eight possible combination haplotypes of SRY/YAP/M9 were identified in the Japanese population, but one of the four haplotypes comprising SRY(T) was absent in the German samples. This suggests that the C to T transition may be more recent than the YAP insertion or the M9 transversion and the change might have occurred in an ancestral Asian population. These results imply that the dimorphism at the SRY gene is one of the Y-linked markers useful for human population studies and also for ethnic identification of forensic samples.

CDNA cloning, tissue expression, and chromosome mapping of human homolog of SOX18.

The SRY (sex-determining region Y) gene encodes a transcription factor characterized by a DNA-binding motif termed the HMG (high mobility group) domain. The SOX (Sry-box) genes comprise a large family related by homology to the HMG-box region. We isolated a cDNA clone with an open reading frame encoding a putative protein of 384 amino acids, which shared 83% identity to the mouse Sox18 protein. Northern blot analysis revealed that a 1.9-kb band of human SOX18 messenger RNAs was predominantly expressed in heart, although weak signals were seen in brain, liver, testis, and leukocyte. By polymerase chain reaction (PCR)-based analyses with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid panel, the gene was mapped to the chromosome 20q13.33 region.

Clinical review 111: familial sex reversal: a review.

Since 1905, it has been recognized that a gene on the Y chromosome, originally termed TDF (for “testes-determining factor”) acted in a dominant fashion to promote male sexual development (1). In 1990, the SRY (sex-determining region Y) gene was identified as TDF (2). This gene was cloned, and its identity was confirmed by studying individuals with sex reversal (phenotypic sex of one type, genetic sex of the other). Subsequent studies of sex-reversed individuals have shown that this gene is neither necessary nor sufficient to promote testis development (3–10). This review will highlight the many observed cases of sex-reversal that have led to the identification of genes other than SRY that promote testicular development and that have suggested a rudimentary genetic pathway. However, rather than focusing on work that has been well-summarized in other reviews, this article will delve into the analysis of cases of sex reversal that are likely to be informative for identifying new genes in the testis-determining pathway (11–13). These cases fall into two categories; either they are associated with novel genetic syndromes or they are familial, with multiple affected individuals within a pedigree. The frequent occurrence of familial sex-reversal suggests that family members other than the proband may be at risk for sex reversal themselves or for having offspring with sex reversal.

Analysis of five Duchenne muscular dystrophy exons and gender determination using conventional duplex polymerase chain reaction on single cells.

We have developed five conventional duplex polymerase chain reaction (PCR) protocols on single lymphocytes and blastomeres from embryos, in order to analyse five exons commonly deleted in deletion-type Duchenne muscular dystrophy (DMD). The five DMD gene exons (17, 19, 44, 45 and 48) can be analysed in separate duplex PCR reactions together with the sex-determining region Y (SRY) gene which enables simultaneous gender assignment. We present here PCR amplification results from single lymphocytes isolated from a normal male (220 cells), a normal female (24 cells) and a male DMD patient (40 cells) carrying a deletion of exons 46-49 within the DMD gene. The method failed to produce a PCR signal for the SRY gene in 8/220 normal male cells (3.6%) and for a DMD exon in 0-4.5% of normal male cells. One negative control out of 112 was positive. When this method was used to analyse two blastomeres from each of five embryos, concordant results were obtained for each pair of blastomeres. All embryos produced signals for the DMD exon tested with four of the embryos found to be male and one female. This method is therefore suitable for preimplantation genetic diagnosis and will allow the transfer of healthy embryos (both male and female) in families carrying DMD gene deletions involving at least one of the five exons 17, 19, 44, 45 and 48.

Abnormalities of gonadal differentiation

Gonadal differentiation involves a complex interplay of developmental pathways. The sex determining region Y (SRY) gene plays a key role in testis determination, but its interaction with other genes is less well understood. Abnormalities of gonadal differentiation result in a range of clinical problems. 46,XY complete gonadal dysgenesis is defined by an absence of testis determination. Subjects have female external genitalia and come to clinical attention because of delayed puberty. Individuals with 46,XY partial gonadal dysgenesis usually present in the newborn period for the valuation of ambiguous genitalia. Gonadal histology always shows an abnormality of seminiferous tubule formation. A diagnosis of 46,XY true hermaphroditism is made if the gonads contain well-formed testicular and ovarian elements. Despite the pivotal role of the SRY gene in testis development, mutations of SRY are unusual in subjects with a 46,XY karyotype and abnormal gonadal development. 46,XX maleness is defined by testis determination in an individual with a 46,XX karyotype. Most affected individuals have a phenotype similar to that of Klinefelter syndrome. In contrast, subjects with 46,XX true hermaphroditism usually present with ambiguous genitalia. The majority of subjects with 46,XX maleness have Y sequences including SRY in genomic DNA. However, only rare subjects with 46,XX true hermaphroditism have translocated sequences encoding SRY. Mosaicism and chimaerism involving the Y chromosome can also be associated with abnormal gonadal development. However, the vast majority of subjects with 45,X/46,XY mosaicism have normal testes and normal male external genitalia.

Sex Determination in Giant Anteater (Myrmecophaga tridactyla) using Hair Roots by Polymerase Chain Reaction Amplification.

The present study was carried out to examine whether the sex of giant anteaters (Myrmecophaga tridactyla), which are not easy to sex from their external genitalia, could be identified using hair root by polymerase chain reaction (PCR) amplification. DNA was extracted from the hair root(s) and amplified by PCR with a pair of primer designed from human sex-determining region Y (SRY) gene. When PCR amplification was applied to the DNA samples extracted from 5 hair roots of each 5 individual of known sex, a signal was only detected in the male, but no signal was detected in the female. In addition, a clear male-specific signal could be detected even when DNA was extracted from a single hair root of the male. Moreover, the nucleotide sequence of this segment in giant anteater exhibited the high similarity with human SRY gene. When PCR amplification was applied to the DNA samples extracted from hair roots of each 10 individual of unknown sex, a male specific signal was detected in 8 individuals including 2 pairs kept in 2 places, but no signal was detected in 2 individuals, suggesting that some institutions had kept 2 giant anteaters as the same sex, not as a couple. The results of this study indicate that PCR amplification with SRY primer pair using DNA from hair root made possible the sensitive, reliable and rapid molecular identification of the sex in giant anteater.

Mutations and sequence variants in the testis-determining region of the Y chromosome in individuals with a 46,XY female phenotype.

The testis-determining gene SRY (sex determining region, Y) is located on the short arm of the Y chromosome and consists of a single exon, the central third of which is predicted to encode a conserved motif with DNA binding/bending properties. We describe the screening of 26 patients who presented with 46,XY partial or complete gonadal dysgenesis for mutations in both the SRY open reading frame (ORF) and in 3.8 kb of Y-specific flanking sequences. DNA samples were screened by using the fluorescence-assisted mismatch analysis (FAMA) method. In two patients, de novo mutations causing complete gonadal dysgenesis were detected in the SRY ORF. One was a nonsense mutation 5' to the HMG box, whereas the other was a missense substitution located at the C terminus of the conserved motif and identical to one previously detected in an unrelated patient. In addition, two Y-specific polymorphisms were found 5' to the SRY gene, and a sequence variant was identified 3' to the SRY polyadenylation site. No duplications of the DSS region in 20 of these patients were detected.

Supernumerary marker chromosomes (SMCs) in Turner syndrome are mostly derived from the Y chromosome.

DNA and FISH (fluorescence in situ hybridization) analysis were carried out in 12 patients with stigmata of Turner syndrome to determine whether the Supernumerary Marker Chromosome (SMC) found cytogenetically in each of these patients was derived from the Y chromosome. The presence of a Y chromosome in these patients may predispose them to develop gonadoblastoma. PCR-Southern blot analysis, followed by FISH, was used to detect the presence of Y chromosome material. The Sex determining Region Y (SRY), Testis Specific Protein Y-encoded (TSPY) and Y-chromosome RNA Recognition Motif (YRRM) genes, which map at Yp11.31, Yp11.1-11.2 and Yp11.2/Yq11.21-11.23, respectively, were selected as markers, because they span the whole Y chromosome, and more importantly, they are considered to be involved in the development of gonadoblastoma. It was shown that in 12 patients, all of whom had an SMC, the SMC of 11 was derived from the Y chromosome. Furthermore, the presence of the SRY, TSPY and YRRM gene sequences was determined and FISH analysis confirmed the Y origin of the SMCs. The methodology described in this report is a rapid, reliable and sensitive approach which may be easily applied to determine the Y origin of an SMC carried in Turner syndrome. The identification of an SMC is important for the clinical management and prognostic counseling of these patients with Turner syndrome.

Genetic basis of human sex determination: An overview

Mammalian sex determination normally depends on the presence and appropriate expression of the SRY (Sex Determining Region, Y) gene. Mutations in this gene can cause failure of testicular development resulting in male to female sex reversal. However, there is increasing evidence for the existence of X-linked and autosomal genes necessary for sex determination or differentiation. The Steroidogenic factor 1 (SF-1) and Wilms' tumor 1 (WT-1) genes are clearly involved in early gonadal development whilst mutations in the SRY-related gene SOX9 are associated with campomelic dysplasia and XY sex reversal. Pedigree analysis of human SRY-negative XX males suggests the existence of at least one autosomal testis determining locus (TDFA). In addition, rearrangements of chromosomes 9, 10 and the X have occasionally been associated with 46,XY gonadal dysgenesis leading to female gender assignment.

THE GENETICS AND BIOCHEMISTRY OF SEX DETERMINATION

The Y chromosome is a dominant induced of testis development mammals. The identification and cloning of SRY, the testis determining gene, depended on the analysis of the genomes of patients with sex reversal syndromes. By analysis of Y chromosome fragments in the genomes of XX males, it was possible to define a 35kb minimum sex determining region(1); SRY (sex determining region y gene, the equivalent mouse gene is Sry) is located within this region(2). De novo mutations in SRY have been found in 15% of XY females(3,4,5) and XX mice transgenic for SRY are sex reversal males(6). The protein encoded by SKY/Sry contains an HMG box, a protein motif associated with DNA binding activity. Recent experiments have demonstrated DNA-binding activity of SRY protein and associated this biochemical activity with sex determination(7,8). This implies that the genes immediately “downstream” of SRY/Sry in the sex determination pathway will be subject to direct transcriptional regulation. Clues to the identity of these “downstream” genes may come from the analysis of the gnomes of Y-sequence negative XX males. Both “upstream” and “downstream” genes may be affected in XY females with intact SRY genes.

Sex-determining region Y (SRY) in a patient with 46,XX true hermaphroditism.

Using a polymerase chain reaction method, a search for Y-specific DNA sequences was made in samples derived from tissues of a 46,XX true hermaphrodite. We found a sequence of SRY in the ovotestis, skin and leukocytes. Other DNA sequences, which covered the pseudoautosomal boundary region, amelogenin gene and DYZ1 locus of Y-chromosome were not detected. The SRY gene detected in the patient by the polymerase chain reaction was not detected by Southern blot analysis, using the SRY fragment as a probe. These findings suggest that in the patient there is a mosaicism of cells with and without part of the Y chromosome, including the SRY sequence. As the SRY sequence was responsible for the development of the gonadal primordium to the ovotestis, SRY seems essential for gonadal differentiation in testis development.

Utilization of the sex-determining region Y gene in beef cattle breeding schemes

AbstractIn mammals ‘maleness’, i.e. the presence of testes, is thought to be controlled by a single gene on the Y chromosome. Recently, a candidate gene termed the SRY (sex-determining region Y) gene has been located. If the SRY gene is the gene causing maleness then a transgenic male with the SRY gene on an autosome would produce a greater proportion of male offspring than a normal male. This would be advantageous in situations where male offspring are more valuable than females. Such transgenic males have a reduced probability of propagating their genotype and an effort has to be made to avoid their extinction. This is at the cost of genetic progress which must be made to enable the transgenics to remain competitive with normal males.In a simulated beef cattle breeding scheme if half of the annual matings were made to transgenics then after 15 years of selection the transgenic males fell the equivalent of 2·6 years of selection behind males in a traditional herd. If all matings were made to transgenics they fell over 9 years behind. Selection for lean food conversion ratio was considered as an example. After 15 years of selection the gain in biological efficiency from more male offspring outweighed the loss from reduced genetic progress only when more than 0·5 of the bulls used in the breeding scheme were normal males. In practice, the difficulty of maintaining a small population of transgenic males along with other costs not included in the calculations suggest that breeding schemes in beef cattle with an SRY transgene would not be practicable without further technology.