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P N Goodfellow

Publications and source records attributed to P N Goodfellow.

At least 73 records · Page 4Linked to original sources
PubMed1994

A method for constructing radiation hybrid maps of whole genomes.

In radiation hybrid mapping, chromosomes in human-rodent hybrid cells are fragmented by X-rays and fragments rescued by fusion of the donor cell to a recipient rodent cell. The co-retention frequencies of markers in 100-200 hybrids are used to map individual chromosomes, but mapping the whole genome in this way is impractical. We have reverted to the original protocols of Goss and Harris and have produced a panel of 44 hybrids using irradiated human fibroblasts as donors. This panel has been used to make a map of human chromosome 14 containing 40 ordered markers. The map integrates previously published maps and localizes nine new markers. We suggest that the construction of a high resolution map of the whole human genome is feasible with a single panel of 100-200 hybrids.

Animals↗
PubMed1994

PBDX is the XG blood group gene.

We have identified the Xga antigen, encoded by the XG blood group gene, by employing rabbit polyclonal and mouse monoclonal antibodies raised against a peptide derived from the N-terminal domain of a candidate gene, referred to earlier as PBDX. In indirect haemagglutination assays, these anti-peptide antibodies react with Xg(a+) but not Xg(a-) erythrocytes. In antibody-specific immobilization of antigen (ASIA) and immunoblot assays, the anti-peptide antibodies react with the same molecule as does human anti-Xga. Therefore, by its identity with PBDX, Xga is identified as a cell-surface protein that is 48% homologous to CD99 (previously designated the 12E7 antigen), the product of MIC2 which is tightly linked to XG. PBDX is renamed here XG.

12E7 Antigen↗
PubMed1994

MIC2R: a transcribed MIC2-related sequence associated with a CpG island in the human pseudoautosomal region.

Sequences related to exons 1, 4 and 5 of the human pseudoautosomal gene MIC2 have been detected on the X and Y chromosomes of humans and other primate species. Isolation of these sequences has defined a new transcribed locus, MIC2R (MIC2-related) which is associated with the second most proximal CpG-rich island in the human pseudoautosomal region. Genomic sequences from the MIC2R locus show that it is composed of a single sequence related to exon 1 and at least four tandem copies of sequences related to exons 4 and 5 of MIC2. Comparison of the four exon 4- and 5-related sequences suggest that they are the result of sequential duplication of a 2.8 kb region during evolution. Transcripts from the MIC2R locus have been detected in all tissues analysed and a number of different transcripts appear to be generated by alternative RNA splicing. However, as none of the transcripts analysed to date contain a significant open reading frame, the function of the MIC2R locus remains unknown.

12E7 Antigen↗
PubMed1993

Rapid sequence evolution of the mammalian sex-determining gene SRY.

In mammals, induction of male sex determination requires the Y-chromosome gene SRY. SRY encodes a protein with a central 'high mobility group' domain (HMG box) of about 78 amino acids. HMG boxes are found in a wide variety of proteins that bind to DNA with high affinity but differing degrees of sequence specificity. The human SRY protein binds to linear DNA with sequence specificity and to cruciform DNA structures without sequence specificity. The DNA-binding activity of the SRY protein resides in the HMG box and mutations in this region are associated with sex reversal in XY females. No function has been ascribed to the portions of the SRY protein outside the HMG box. SRY belongs to a family of genes that are related by sequence homology within the DNA-binding domain: the genes most similar to SRY (> 60%) have been named SOX genes (SRY box genes). None of the known SOX genes is homologous to SRY outside the HMG-box region. Although SRY is an important developmental regulator, its sequence is poorly conserved between species apart from the HMG-box domain. Here we investigate the coding sequence of SRY in primates and find that evolution has been rapid in the regions flanking the conserved domain. The high degree of sequence divergence and the frequency of non-synonymous mutations suggest either that the majority of the coding sequence has no functional significance or that directional selection has occurred.

Amino Acid Sequence↗
PubMed1993

Genetic maps.

The same genetic principles are common to all animals, plants and microorganisms. One consequence of the generality of genetic principles is that methods developed in one organism can often be used in other species. Recent advances in mammalian molecular genetics, genome analysis, and gene mapping have been found to be directly applicable to other animals and even plants. This is facilitating the rapid construction of detailed genetic maps in a wide variety of species. Similar advances are being made in the development of manipulation techniques, which allow the genomic deletion and addition of specific genes as well as more subtle alterations. Armed with detailed maps and precise manipulation techniques it is possible to associate genes with phenotypes, test the function of genes and to unravel complex traits that depend on the interaction of different genes.

Animals↗
PubMed1993

Characterization and mapping of the human SOX4 gene.

The SOX genes comprise a large family related by homology to the HMG-box region of the testis-determining gene SRY. We have cloned and sequenced the human SOX4 gene. The open reading frame encodes a 474 amino acid protein, which includes an HMG-box. The non-box sequence is particularly rich in serine residues and has several polyglycine and polyalanine stretches. With somatic cell hybrids, human SOX4 has been mapped to Chromosome (Chr) 6p distal to the MHC region. There is no evidence for clustering of other members of the SOX1, -2, and -3 or SOX4 gene families around the SOX4 locus.

Amino Acid Sequence↗
PubMed1993

Comparative mapping of SRY in the great apes.

Cytogenetic studies of the primate Y chromosomes have suggested that extensive rearrangements have occurred during evolution of the great apes. We have used in situ hybridization to define these rearrangements at the molecular level. pHU-14, a probe including sequences from the sex determining gene SRY, hybridizes close to the early replicating pseudoautosomal segment in a telomeric or subtelomeric position of the Y chromosomes of all great apes. The low copy repeat detected by the probe Fr35-II is obviously included in Y chromosomal rearrangements during hominid evolution. These results, combined with previous studies, suggest that the Y chromosome in great apes has a conserved region including the pseudoautosomal region and the testis-determining region. The rest of the Y chromosome has undergone several rearrangements in the different great apes.

Animals↗
PubMed1993

The human SRY transcript.

SRY encodes the Y-linked testis-determining factor in humans. A predominant 900 bp transcript originates from a single exon and encompasses the putative SRY coding sequence. We show that in human adult testis SRY transcription involves multiple start sites. In addition to a previously defined major initiation site, transcripts originating at least 410 bp upstream of this site were detected. Using a cDNA specific RT-PCR assay, embryonic and adult human tissues were screened for SRY expression. In humans, SRY transcription is not restricted to the presumptive and the mature gonadal tissues in the embryo and the adult respectively but can be detected in a range of other locations. Two human cell lines, NTERA-2 cl.D1 (NT2/D1) and Hep G2, have been identified which express SRY at similar levels to adult testis. The NT2/D1 SRY transcripts appear to have the same structure as those in adult testis. HMBA-induced differentiation of NT2/D1 cells results in a diminution of SRY mRNA, while transcription of SRY in retinoic acid differentiated NT2/D1 is unaffected.

Adult↗
PubMed1993

SOX3 is an X-linked gene related to SRY.

The mammalian genome contains a family of genes that are related to SRY, the mammalian sex determining gene. The homology is restricted to the region of SRY that encodes a DNA binding motif of the HMG-box class. These genes have been named SOX genes (SRY-related HMG-box genes). We have cloned and characterised SOX3, a member of the human SOX gene family. SOX3 maps to the X chromosome in the region Xq26-27. A mentally retarded male patient with haemophilia B is deleted for both the Factor IX gene and SOX3. This suggests that SOX3 is not essential for testis formation. The phenotype of the patient and the expression of SOX3 gene in neuronal tissues raises the possibility that this gene is a candidate gene for Borjeson-Forssman-Lehmann, an X-linked mental retardation syndrome.

Adult↗
PubMed1993

The genomic organisation of the human pseudoautosomal gene MIC2 and the detection of a related locus.

The human pseudoautosomal gene MIC2 encodes a 185 amino acid cell surface antigen recognised by the monoclonal antibody 12E7. The gene is abundantly expressed in all tissues tested and a role in cell-cell interactions has been suggested. We describe here the isolation of 95kb of genomic DNA encompassing the entire MIC2 gene. The gene is 52kb in size and orientated towards the centromere. As predicted by previous genetic studies, the 5' end of MIC2 is located 95kb from the pseudoautosomal boundary and confirming that the elevated rate of recombination in pseudoautosomal region is continuous up to the boundary. The gene is divided into ten exons which show correlation with predicted domains of the protein and are considerably smaller than the average for mammalian genes. Evolutionary studies indicate that the gene can be detected by DNA hybridisation only in primates, however genomic probes for both exons 1 and 5 detect related locus present on both the human X and Y chromosomes.

12E7 Antigen↗
PubMed1993

The role of the sex-determining region Y gene in the etiology of 46,XX maleness.

The condition of 46,XX maleness is characterized by testicular development in subjects who have two X chromosomes but who lack a normal Y chromosome. Several etiologies have been proposed to explain 46,XX maleness: 1) translocation of the testis-determining factor from the Y to the X chromosome, 2) mutation in an autosomal or X chromosome gene which permits testicular determination in the absence of TDF, and 3) undetected mosaicism with a Y-bearing cell line. We evaluated 10 affected subjects who were ascertained for different reasons and who had several distinct phenotypes. Six subjects had inherited sequences from the short arm of the Y chromosome including the sex-determining region Y gene (SRY). Five of the subjects were pubertal at the time of evaluation and had a phenotype similar to that of Klinefelter syndrome with evidence of Sertoli cell and Leydig cell dysfunction. One subject had evidence from Southern blot analysis and in situ hybridization for the presence of an intact Y chromosome in approximately 1% of cells. Three subjects lacked Y sequences by Southern blot analysis and by polymerase chain reaction amplification of SRY. These subjects were ascertained in the newborn period because of congenital anomalies. One had multiple anomalies including cardiac abnormalities; one had cardiac anomalies alone; and one had ambiguous genitalia. Our data confirm the genetic heterogeneity of 46,XX maleness, in which some subjects have SRY while other subjects lack it. In addition, there is phenotypic heterogeneity among subjects who lack SRY suggesting that there is also genetic heterogeneity within this subgroup.

DNA Restriction Enzymes↗
PubMed1993

Report of a kindred with X-linked (or autosomal dominant sex-limited) 46,XY partial gonadal dysgenesis.

The condition termed 46,XY complete gonadal dysgenesis is characterized by the lack of testicular determination with resulting streak gonads, normal Mullerian structures, and female external genitalia. In the partial form, there is incomplete testicular determination with a wide range in the degree of ambiguous genitalia and sexual duct development. We evaluated a kindred in which a partial form of 46,XY gonadal dysgenesis occurred in four subjects from two generations. Pedigree analysis indicated an X-linked or possibly an autosomal sex-limited mode of inheritance. All affected subjects were ascertained because of ambiguous genitalia with minimal virilization. At 10 days of age, the proband had a subnormal plasma level of testosterone, and at 4 months, there was no rise in plasma T after stimulation with hCG. At laparotomy, a dysgenetic gonad was found on the right side, but no gonad was found on the left side. A vas deferens was present on the right, indicating the presence of functional Leydig cells early in fetal life. In the other affected subjects, gonadal tissue was also limited to one side of the abdomen and showed poorly developed seminiferous tubules. The sex-determining region Y gene, which encodes the testis-determining factor, was present and unaltered in the genomic DNA of all affected subjects. Duplication of the distal short arm of the X-chromosome has been associated with 46,XY complete gonadal dysgenesis in some patients. In our studies, Southern blot analysis revealed that sequences of the distal short arm of the X-chromosome (DXS9 to DXS84) were present in single copy, excluding a large duplication in this area of the X. Several kindreds with familial 46,XY complete gonadal dysgenesis have been reported; five of them had evidence of an X-linked mode of inheritance. Our study of a kindred with 46,XY partial gonadal dysgenesis further supports the role of an X chromosome gene in testicular determination. Evidence of some fetal Leydig cell function in the affected subjects of our report suggests that mutations of the putative X-chromosome gene can result in a partial as well as complete defect in testicular determination.

Blotting, Southern↗