The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Michael F. Hammer - One of the best experts on this subject based on the ideXlab platform.
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Human Evolution and the Y Chromosome
Current Opinion in Genetics & Development, 1996Co-Authors: R. John Mitchell, Michael F. HammerAbstract:The past two Years have seen the increased studY of Y-Chromosome polYmorphisms and their relationship to human evolution and variation. Low Y-Chromosome sequence diversitY indicates that the common ancestor of all extant Y Chromosomes lived relativelY recentlY and the consensus of estimates of time to the most recent common ancestor concur with estimates of the mitochondrial DNA ancestor; but we do not know where this ‘Adam’ lived. Though the reason for low nucleotide diversitY on the Y-Chromosome remains unresolved, some of the mutations are proving highlY informative in tracing human prehistoric migrations and are generating new hYpotheses on human colonizations and migrations. The recent discoverY of highlY polYmorphic microsatellites on the Y offers new possibilities for the investigation of more recent human evolutionarY events, including the identification of male founders.
Antonino Forabosco - One of the best experts on this subject based on the ideXlab platform.
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gonadoblastoma in turner sYndrome and Y Chromosome derived material
American Journal of Medical Genetics Part A, 2005Co-Authors: Laura Mazzanti, A Cicognani, Lilia Baldazzi, R Bergamaschi, Emanuela Scarano, Simona Strocchi, Annalisa Nicoletti, Francesca Mencarelli, Mariacarla Pittalis, Antonino ForaboscoAbstract:The identification of Y-Chromosome material is important in females with Ullrich-Turner sYndrome (UTS) due to the risk of developing gonadoblastoma or other gonadal tumors. There is controversY regarding the frequencY of the Y-Chromosome-derived material and the occurrence of gonadoblastoma in these patients. The aim of our studY was to evaluate a large number of patients with UTS, followed before and during the pubertal age for the prevalence of Y-Chromosome derived material, the occurrence of gonadoblastoma, and the incidence of possible neoplastic degeneration. An unselected series of 171 patients with UTS (1-34 Years old), diagnosed cYtogeneticallY, was studied for Y-Chromosome markers (SRY and Y-centromeric DYZ3 repeats). The follow-up was of 2-22 Years; 101 of these patients were followed during pubertal age. Y-Chromosome material was found in 14 patients (8%): 12 of these were gonadectomized (2.8-25.9 Years). A gonadoblastoma was detected in four patients under 16 Years of age: in two, Y-material was detected onlY at molecular analYsis (at conventional cYtogenetic analYsis, one was included in the 45,X group and one in the X + mar group) and one had also an immature teratoma and an endodermal sinus carcinoma. The prevalence of gonadoblastoma in our series of gonadectomized UTS patients with Y-positive material was of 33.3% (4/12). Our data suggest that the age of appearance and the possibilitY of malignant degeneration of gonadoblastoma can occur earlY in life. These patients, in particular those with 45,X or a marker Chromosome maY benefit from molecular screening to detect the presence of Y-Chromosome material; PCR is a rapid and inexpensive technique. At the moment, laparoscopY and preventive gonadectomY performed as soon as possible remain the procedures of choice for patients with UTS, when Y-Chromosome has been identified, as we are still unable to predict a future malignant evolution of gonadoblastoma.
Y Fukushima - One of the best experts on this subject based on the ideXlab platform.
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Molecular cloning and mapping of 10 new probes on the human Y Chromosome
Genomics, 1991Co-Authors: Y. Nakahori, KATSUJI FUKUTANI, Kazuya Fujieda, Yoshikatsu Kuroki, Seiho Nagafuchi, Hiroshi Fuse, Shigeru Minowada, K Hayashi, T Tamura, Y FukushimaAbstract:We have developed a novel positive cloning vector whose use precludes the cloning of anY fragments less than 0.8 kb as well as 3.4-kb EcoRI fragments of DYZ1, the largest repeating-DNA familY on the long arm of the human Y Chromosome. Using this vector, we subcloned inserts of a Y-Chromosome-specific phage librarY constructed from EcoRI-digested flow-sorted Y-Chromosome DNA. Ten novel Y-specific fragments were obtained. Their localization on the Y Chromosome was determined bY deletion mapping using clinical samples with structurallY abnormal Y Chromosomes. The long arm of the Y Chromosome was divided into 12 segments bY the novel probes in combination with established probes. The amelogenin-like sequence, mapped on the long arm in Human Gene Mapping 10, has been mapped on the short arm. © 1991.
Yann Guiguen - One of the best experts on this subject based on the ideXlab platform.
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the sexuallY dimorphic on the Y Chromosome gene sdY is a conserved male specific Y Chromosome sequence in manY salmonids
Evolutionary Applications, 2013Co-Authors: Ayaka Yano, Barbara Nicol, Elodie Jouanno, Edwige Quillet, Alexis Fostier, Rene Guyomard, Yann GuiguenAbstract:All salmonid species investigated to date have been characterized with a male heterogametic sex-determination sYstem. However, as these species do not share anY Y-Chromosome conserved sYntenY, there remains a debate on whether theY share a common master sex-determining gene. In this studY, we investigated the extent of conservation and evolution of the rainbow trout (OncorhYnchus mYkiss) master sex-determining gene, sdY (sexuallY dimorphic on the Y-Chromosome), in 15 different species of salmonids. We found that the sdY sequence is highlY conserved in all salmonids and that sdY is a male-specific Y-Chromosome gene in the majoritY of these species. These findings demonstrate that most salmonids share a conserved sex-determining locus and also stronglY suggest that sdY maY be this conserved master sex-determining gene. However, in two whitefish species (subfamilY Coregoninae), sdY was found both in males and females, suggesting that alternative sex-determination sYstems maY have also evolved in this familY. Based on the wide conservation of sdY as a male-specific Y-Chromosome gene, efficient and easY molecular sexing techniques can now be developed that will be of great interest for studYing these economicallY and environmentallY important species.
R. John Mitchell - One of the best experts on this subject based on the ideXlab platform.
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Human Evolution and the Y Chromosome
Current Opinion in Genetics & Development, 1996Co-Authors: R. John Mitchell, Michael F. HammerAbstract:The past two Years have seen the increased studY of Y-Chromosome polYmorphisms and their relationship to human evolution and variation. Low Y-Chromosome sequence diversitY indicates that the common ancestor of all extant Y Chromosomes lived relativelY recentlY and the consensus of estimates of time to the most recent common ancestor concur with estimates of the mitochondrial DNA ancestor; but we do not know where this ‘Adam’ lived. Though the reason for low nucleotide diversitY on the Y-Chromosome remains unresolved, some of the mutations are proving highlY informative in tracing human prehistoric migrations and are generating new hYpotheses on human colonizations and migrations. The recent discoverY of highlY polYmorphic microsatellites on the Y offers new possibilities for the investigation of more recent human evolutionarY events, including the identification of male founders.
