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P N Goodfellow

Publications and source records attributed to P N Goodfellow.

At least 55 records · Page 3Linked to original sources
PubMed1996

Mutation analysis of the 2 kb 5' to SRY in XY females and XY intersex subjects.

Mutations in the Y linked testis determining gene SRY cause 46,XY sex reversal. However, only about 15% of cases of 46,XY sex reversal are accounted for by mutations in SRY. In this study we have investigated the possibility that mutations affecting the expression of SRY might cause some of the cases of sex reversal in which the coding sequence of SRY is normal. We have screened 2 kb of DNA immediately 5' to the SRY coding sequence in 49 subjects with varying degrees of 46,XY sex reversal. Two variant bases were identified, one of which was determined to be a polymorphism and the other is unique, but familial.

DNA Mutational Analysis↗
PubMed1996

Evidence to exclude SOX9 as a candidate gene for XY sex reversal without skeletal malformation.

The skeletal malformation syndrome campomelic dysplasia (CMD1) is caused by mutations within the SOX9 gene or chromosomal rearrangement breakpoints outside SOX9. Approximately three quarters of cases of CMD1 in XY subjects show complete or partial sex reversal. As some mutations cause CMD1 alone and others cause CMD1 and sex reversal, it is conceivable that some mutations might cause sex reversal in the absence of CMD1. In this study, we have investigated this possibility by screening the entire coding region of SOX9 in 30 patients with a spectrum of XY sex reversal phenotypes. No mutations were identified, suggesting that SOX9 should not be considered a candidate gene for XY sex reversal without skeletal malformation.

Disorders of Sex Development↗
PubMed1996

A high-resolution radiation hybrid map of the region surrounding the Gorlin syndrome gene.

We have constructed a set of hybrid cell lines by irradiation of GM 64063 (human chromosome 9q only on hamster background) and fusion to hamster A23 Tk-, 109 independent lines were tested by PCR with 24 markers from chromosome 9q. The marker density is highest in the 9q22.3-q31 region containing the gene for Gorlin syndrome, a familial predisposition to basal cell carcinoma. The resolution of our map in this region is significantly higher than other published maps and will enable accurate placing of new markers and genes within the 9q22.3-q3.1 region. This is important since yeast artificial chromosomes from the region are likely to contain deletions.

Animals↗
PubMed1996

A comparison of the properties of Sox-3 with Sry and two related genes, Sox-1 and Sox-2.

The Sox gene family consists of a large number of embryonically expressed genes related via the possession of a 79-amino-acid DNA-binding domain known as the HMG box. Partial clones for the first three Sox genes (al-a3) were isolated by homology to the HMG box of the testis-determining gene Sry and are now termed Sox-1, Sox-2 and Sox-3, Sox-3 is highly conserved amongst mammalian species and is located on the X chromosome. This has led to the proposal that Sry evolved from Sox-3. We present the cloning and sequencing of Sox-1, Sox-2 and Sox-3 from the mouse and show that Sox-3 is most closely relate to Sry. We also confirm that mouse Sox-3 is located on the X chromosome between Hprt and Dmd. Analysis of the distribution of Sox-3 RNA shows that its main site of expression is in the developing central nervous system, suggesting a role for Sox-3 in neural development. Moreover, we demonstrate that Sox-3, as well as Sox-1 and Sox-2, are expressed in the urogenital ridge and that their protein products are able to bind the same DNA sequence motif as Sry in vitro, but with different affinities. These observations prompt discussion of an evolutionary link between the genes and support the model that Sry has evolved from Sox-3. However our findings imply that if this is true, then Sry has undergone concomitant changes resulting in loss of CNS expression and altered DNA-binding properties.

Amino Acid Sequence↗
PubMed1995

Interaction of normal and mutant SRY proteins with DNA.

In mammals, sex determination is caused by the Y-chromosome gene SRY. The DNA-binding domain of human SRY protein is similar to those of the chromatin protein HMG1. Like HMG1, SRY binds to kinked DNA structures, and bends linear DNA sharply upon binding. We analysed the biochemical properties of mutant SRY proteins from five patients with complete gonadal dysgenesis: two bind and bend DNA almost normally, two bind inefficiently but bend DNA normally, and one binds DNA with almost normal affinity but produces a different angle. The mutations with moderate effect on complex formation can be transmitted to progeny, the ones with severe effects on either binding or bending are de novo. The angle induced by SRY depends on the exact DNA sequence, thus discriminating different target sites. We suggest that the exact spatial arrangement of the nucleoprotein complex organized by SRY in chromatin is essential for the expression of genes involved in testis differentiation.

Base Sequence↗
PubMed1995

The role of SOX9 in autosomal sex reversal and campomelic dysplasia.

In eutherian mammals, the Y-chromosome gene SRY is required for induction of testis development. Although the Y chromosome is sex determining, loci located elsewhere in the genome participate in the complex cascade of genetic interactions required to form a testis. Male to female sex reversal (46,XY females) occurs at a high frequency in individuals afflicted with the skeletal malformation syndrome campomelic dysplasia. Chromosomal translocations in individuals with both syndromes had localized an autosomal sex reversal locus (SRA1) and a campomelic dysplasia locus (CMPD1) to the long arm of human chromosome 17. The molecular cloning of a translocation breakpoint in a sex reversed campomelic dysplasia patient revealed its proximity to SOX9, a gene which is related to SRY. Analysis of SO X9 in patients without chromosomal rearrangements demonstrated single allele mutations in sex reversed campomelic individuals, linking this gene with both bone formation and control of testis development. Identification of SO X9 as SRA1/CMPD1 and the role of SO X9 mutations in sex reversal and campomelic dysplasia are discussed.

Biological Evolution↗
PubMed1995

Sequence variation of the human Y chromosome.

We have generated over 100 kilobases of sequence from the nonrecombining portion of the Y chromosomes from five humans and one common chimpanzee. The human subjects were chosen to match the earliest branches of the human mitochondrial tree. The survey of 18.3 kilobases from each human detected only three sites at which substitutions were present, whereas the human and chimpanzee sequences showed 1.3% divergence. The coalescence time estimated from our Y chromosome sample is more recent than that of the mitochondrial genome. A recent coalescence time for the Y chromosome could have been caused by the selected sweep of an advantageous Y chromosome or extensive migration of human males.

Animals↗
PubMed1995

41 kilobases of analyzed sequence from the pseudoautosomal and sex-determining regions of the short arm of the human Y chromosome.

Determination of 41.2 kb of Y chromosome genomic sequence has been made from a cosmid that spans the Yp pseudoautosomal boundary and includes 18.5 kb of sequence from the patient-defined sex-determining region of the Y chromosome. An AceDB database of the sequence and the analysis data have been produced as a resource for studies of the evolution and population genetics of the Y chromosome. Comparison of the 18.5 kb from the sex determining region to the sex determining region of mouse does not locate any areas of similarity outside SRY/Sry. Indeed, no coding regions other than those previously reported can be detected anywhere in the 41 kb. The Y-specific and pseudoautosomal portions of this sequence have different repeat sequence and GC contents: this may have relevance both to the events defining the pseudoautosomal boundary and to the course of sequence evolution in the absence of recombination.

Animals↗
PubMed1995

Evolutionary conservation in the DNA-binding and -bending properties of HMG-boxes from SRY proteins of primates.

Mammalian sex determination is caused by the Y-chromosome gene SRY, which encodes a protein containing a DNA-binding domain (HMG-box) of about 70 amino acids (aa). The HMG-box is very conserved in a wide variety of mammals; conversely, the flanking non-box regions show a high degree of aa sequence divergence, even between closely related species. The HMG-box of human SRY binds sequence-specifically to linear DNA and produces a sharp bend; it also interacts with high affinity to kinked DNA structures irrespective of their sequences. Point mutations associated with sex reversal in XY human females fall within the HMG-box and either affect the affinity for DNA or modify the geometry of the DNA-protein complex. Here, we show that the DNA-binding and -bending properties of the HMG-boxes of SRY from human and seven different primates are extremely similar to each other. Together with other data, this suggests that the inability of mouse and human SRY to substitute for each other is due to differences in the conserved HMG-box, rather than the non-conserved flanking sequences.

Amino Acid Sequence↗
PubMed1995

Irradiation and fusion gene transfer.

Irradiation and fusion gene transfer (IFGT) is a technique that spans the gap between the limitations of molecular methods and somatic-cell genetics, allowing the separation of DNA fragments between 0.25 and 30 Mb in size. In conjunction with genetic linkage analysis and physical mapping techniques, IFGT provides a very useful addition to methods for cloning disease loci, and mapping chromosomes and entire genomes.

Animals↗
PubMed1995

The human Y chromosome homologue of XG: transcription of a naturally truncated gene.

The XG blood group gene spans PABX1, the pseudoautosomal boundary on the X chromosome. The first three exons are pseudoautosomal and the remaining seven are X-specific. On the Y chromosome SRY and RPS4Y are located in Y-specific sequences within 70 kb of the boundary. Transcription from the XG promoter on the Y chromosome has been detected by cDNA cloning and PCR-based methods. Splicing of the pseudoautosomal exon 3 of XG occurs to multiple sites in Y-specific sequences. Transcripts detected include antisense SRY sequences and XG approximately RPS4Y hybrid transcripts. The heterogeneity and low abundance of transcripts as well as the lack of maintenance of the XG open reading frame in all but one transcript argue against a specific Y-chromosome gene product. An expressed pseudogene of XG, XGPY, has been mapped to interval Yq11.21. XGPY is transcribed and subject to alternative splicing. Sequence comparison suggests that XGPY originated from XG by a gene duplication event in the primate lineage.

Alternative Splicing↗
PubMed1994

Sex-reversing mutations affect the architecture of SRY-DNA complexes.

The testis determining factor, SRY, is a DNA binding protein that causes a large distortion of its DNA target sites. We have analysed the biochemical properties of the DNA binding domains (HMG-boxes) of mutant SRY proteins from five patients with complete gonadal dysgenesis. The mutant proteins fall into three categories: two bind and bend DNA almost normally, two bind inefficiently but bend DNA normally and one binds DNA with almost normal affinity but produces a different angle. The mutations with moderate effect on complex formation can be transmitted to male progeny, the ones with severe effects on either binding or bending are de novo. The angle induced by SRY depends on the exact DNA sequence and thus adds another level of discrimination in target site recognition. These data suggest that the exact spatial arrangement of the nucleoprotein complex organized by SRY is essential for sex determination.

Base Sequence↗
PubMed1994

Campomelic dysplasia and autosomal sex reversal caused by mutations in an SRY-related gene.

Induction of testis development in mammals requires the presence of the Y-chromosome gene SRY. This gene must exert its effect by interacting with other genes in the sex-determination pathway. Cloning of a translocation chromosome breakpoint from a sex-reversed patient with campomelic dysplasia, followed by mutation analysis of an adjacent gene, indicates that SOX9, an SRY-related gene, is involved in both bone formation and control of testis development.

Amino Acid Sequence↗
PubMed1994

The biochemical role of SRY in sex determination.

The human sex-determining gene on the Y chromosome, termed SRY, has recently been isolated by positional cloning; compelling evidence now exists equating SRY with the testis-determining factor, TDF. The SRY gene product is an HMG box protein whose DNA-binding activity is vital for testis formation as sex-reversed patients with SRY mutations lack this activity in vitro. The in vivo DNA target for SRY, however, remains elusive. Here, we show, by gel retardation analysis, that SRY recognises specific DNA sequences and that such sequences exist upstream of the AMH promoter, a potential downstream target for SRY. We also describe the DNA bending and cruciform DNA-binding functions of SRY and propose a model for the potential action of SRY in the "HMG-1-rich" mammalian nucleus.

Amino Acid Sequence↗
PubMed1994

Cloning of PBDX, an MIC2-related gene that spans the pseudoautosomal boundary on chromosome Xp.

The pseudoautosomal boundaries are the interface between pseudoautosomal and sex chromosome-specific DNA sequences. We have isolated a gene, PBDX, from the human pseudoautosomal boundary region of Xp. The three exons at the 5' end of PBDX are situated in the pseudoautosomal region immediately downstream of MIC2, whereas the other seven exons are in the X-specific region. Hence, PBDX is inherited in two modes: its 5' end is pseudoautosomally inherited and its 3' end is X-linked. The predicted amino acid sequence of the 540 bp coding region is 48% homologous to 12E7, the product of MIC2. By virtue of its position, PBDX becomes an excellent candidate for the XG blood group gene.

12E7 Antigen↗