The Experts below are selected from a list of 48327 Experts worldwide ranked by ideXlab platform
Michael J. Rutter - One of the best experts on this subject based on the ideXlab platform.
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association of anterior glottic webs with velocardiofacial syndrome Chromosome 22q11 2 Deletion
Otolaryngology-Head and Neck Surgery, 2004Co-Authors: Christopher R Miyamoto, Alan F Rope, Robert J Hopkin, Sally R. Shott, Robin T. Cotton, Aliza P. Cohen, Michael J. RutterAbstract:OBJECTIVE: An association between anterior glottic webs and velocardiofacial syndrome (Chromosome 22q11.2 Deletion) has previously been noted in a number of case reports. Our objective was to determine if the presence of such webs warrants a high index of suspicion for this Chromosome Deletion. Study design and setting This study was carried out in the Division of Pediatric Otolaryngology-Head and Neck Surgery at Cincinnati Children's Hospital Medical Center. Chromosome 22q11.2 Deletion status was determined for all patients endoscopically diagnosed with anterior glottic webs between July 1998 and December 2000. Families of patients who tested positive for the Deletion were referred to the Cincinnati Children's Division of Human Genetics for additional evaluation and counseling. RESULTS: Eleven of 17 patients (65%) with anterior glottic webs were positive for Chromosome 22q11.2 Deletion. Of these 11 patients, 5 showed subtle clinical manifestations of velocardiofacial syndrome and underwent genetic testing due only to the presence of a web. All 11 patients were diagnosed with velocardiofacial syndrome. CONCLUSION: We strongly recommend that all patients diagnosed with anterior glottic webs undergo fluorescence in situ hybridization evaluation for this Chromosome Deletion.
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association of anterior glottic webs with velocardiofacial syndrome Chromosome 22q11 2 Deletion
Otolaryngology-Head and Neck Surgery, 2004Co-Authors: Christopher R Miyamoto, Alan F Rope, Robert J Hopkin, Sally R. Shott, Robin T. Cotton, Aliza P. Cohen, Michael J. RutterAbstract:OBJECTIVE: An association between anterior glottic webs and velocardiofacial syndrome (Chromosome 22q11.2 Deletion) has previously been noted in a number of case reports. Our objective was to determine if the presence of such webs warrants a high index of suspicion for this Chromosome Deletion. Study design and setting This study was carried out in the Division of Pediatric Otolaryngology-Head and Neck Surgery at Cincinnati Children's Hospital Medical Center. Chromosome 22q11.2 Deletion status was determined for all patients endoscopically diagnosed with anterior glottic webs between July 1998 and December 2000. Families of patients who tested positive for the Deletion were referred to the Cincinnati Children's Division of Human Genetics for additional evaluation and counseling. RESULTS: Eleven of 17 patients (65%) with anterior glottic webs were positive for Chromosome 22q11.2 Deletion. Of these 11 patients, 5 showed subtle clinical manifestations of velocardiofacial syndrome and underwent genetic testing due only to the presence of a web. All 11 patients were diagnosed with velocardiofacial syndrome. CONCLUSION: We strongly recommend that all patients diagnosed with anterior glottic webs undergo fluorescence in situ hybridization evaluation for this Chromosome Deletion.
Eva H Stukenbrock - One of the best experts on this subject based on the ideXlab platform.
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meiotic drive of female inherited supernumerary Chromosomes in a pathogenic fungus
eLife, 2018Co-Authors: Michael Habig, Gert H J Kema, Eva H StukenbrockAbstract:Meiosis is a key cellular process of sexual reproduction that includes pairing of homologous sequences. In many species however, meiosis can also involve the segregation of supernumerary Chromosomes, which can lack a homolog. How these unpaired Chromosomes undergo meiosis is largely unknown. In this study we investigated Chromosome segregation during meiosis in the haploid fungus Zymoseptoria tritici that possesses a large complement of supernumerary Chromosomes. We used isogenic whole Chromosome Deletion strains to compare meiotic transmission of Chromosomes when paired and unpaired. Unpaired Chromosomes inherited from the male parent as well as paired supernumerary Chromosomes in general showed Mendelian inheritance. In contrast, unpaired Chromosomes inherited from the female parent showed non-Mendelian inheritance but were amplified and transmitted to all meiotic products. We concluded that the supernumerary Chromosomes of Z. tritici show a meiotic drive and propose an additional feedback mechanism during meiosis, which initiates amplification of unpaired female-inherited Chromosomes.
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meiotic drive of female inherited supernumerary Chromosomes in a pathogenic fungus
bioRxiv, 2018Co-Authors: Michael Habig, Gert H J Kema, Eva H StukenbrockAbstract:Meiosis is a key cellular process of sexual reproduction involving the pairing of homologous sequences. In many species however, meiosis can also involve the segregation of supernumerary Chromosomes, which can lack a homolog. How these unpaired Chromosomes undergo meiosis is largely unknown. In this study we investigated Chromosome segregation during meiosis in the haploid fungus Zymoseptoria tritici that possesses a large complement of supernumerary Chromosomes. We used isogenic whole Chromosome Deletion strains to compare meiotic transmission of Chromosomes when paired and unpaired. Unpaired Chromosomes inherited from the male parent as well as paired supernumerary Chromosomes showed Mendelian inheritance. In contrast, unpaired Chromosomes inherited from the female parent showed non-Mendelian inheritance but were amplified and transmitted to all meiotic products. We concluded that the supernumerary Chromosomes of Z. tritici show a meiotic drive and propose an additional feedback mechanism during meiosis which initiates amplification of unpaired female-inherited Chromosomes.
Jitka Zluvova - One of the best experts on this subject based on the ideXlab platform.
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early events in the evolution of the silene latifolia y Chromosome male specialization and recombination arrest
Genetics, 2007Co-Authors: Jitka Zluvova, Boris Vyskot, Bohuslav Janousek, S Georgiev, Ioan NegrutiuAbstract:Understanding the origin and evolution of sex Chromosomes requires studying recently evolved X–Y Chromosome systems such as those in some flowering plants. We describe Y Chromosome Deletion mutants of Silene latifolia, a dioecious plant with heteromorphic sex Chromosomes. The combination of results from new and previously described Deletions with histological descriptions of their stamen development defects indicates the presence of two distinct Y regions containing loci with indispensable roles in male reproduction. We determined their positions relative to the two main sex determination functions (female suppressing and the other male promoting). A region proximal to the centromere on the Y p arm containing the putative stamen promoting sex determination locus includes additional early stamen developmental factors. A medial region of the Y q arm carries late pollen fertility factors. Cytological analysis of meiotic X–Y pairing in one of the male-sterile mutants indicates that the Y carries sequences or functions specifically affecting sex Chromosome pairing.
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comparison of the x and y Chromosome organization in silene latifolia
Genetics, 2005Co-Authors: Jitka Zluvova, Bohuslav Janousek, Ioan Negrutiu, Boris VyskotAbstract:Here we compare gene orders on the Silene latifolia sex Chromosomes. On the basis of the Deletion mapping results (11 markers and 23 independent Y Chromosome Deletion lines used), we conclude that a part of the Y Chromosome (covering a region corresponding to at least 23.9 cM on the X Chromosome) has been inverted. The gradient in silent-site divergence suggests that this inversion took place after the recombination arrest in this region. Because recombination arrest events followed by Y Chromosome rearrangements also have been found in the human Y Chromosome, this process seems to be a general evolutionary pathway.
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the inter specific hybrid silene latifolia x s viscosa reveals early events of sex Chromosome evolution
Evolution & Development, 2005Co-Authors: Jitka Zluvova, Boris Vyskot, Roman Hobza, M. Lengerova, Ioan Negrutiu, Michaela Marková, Michael Nicolas, Bohuslav JanousekAbstract:The dioecious plant species Silene latifolia has a sex determination mechanism based on an active Y Chromosome. Here, we used inter-specific hybrids in the genus Silene to study the effects of gene complexes on the Y Chromosome. If the function of Y-linked genes has been maintained in the same state as in the hermaphrodite progenitor species, it should be possible to substitute such genes by genes coming from a related hermaphrodite species. In the inter-specific hybrid, S. latifolia x S. viscosa, anthers indeed develop far beyond the early bilobal stage characteristic of XX S. latifolia female plants. The S. viscosa genome can thus replace the key sex determination gene whose absence abolishes early stamen development in females (loss of the stamen-promoting function, SPF), so that hybrid plants are morphologically hermaphrodite. However, the hybrids have two anther development defects, loss of adhesion of the tapetum to the endothecium, and precocious endothecium maturation. Both these defects were also found in independent Y-Chromosome Deletion mutants of S. latifolia. The data support the hypothesis that the evolution of complete gender dimorphism from hermaphroditism involved a major largely recessive male-sterility factor that created females, and the appearance of new, dominant genes on the Y Chromosome, including both the well-documented gynoecium-suppressing factor, and two other Y specific genes promoting anther development.
Christopher R Miyamoto - One of the best experts on this subject based on the ideXlab platform.
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association of anterior glottic webs with velocardiofacial syndrome Chromosome 22q11 2 Deletion
Otolaryngology-Head and Neck Surgery, 2004Co-Authors: Christopher R Miyamoto, Alan F Rope, Robert J Hopkin, Sally R. Shott, Robin T. Cotton, Aliza P. Cohen, Michael J. RutterAbstract:OBJECTIVE: An association between anterior glottic webs and velocardiofacial syndrome (Chromosome 22q11.2 Deletion) has previously been noted in a number of case reports. Our objective was to determine if the presence of such webs warrants a high index of suspicion for this Chromosome Deletion. Study design and setting This study was carried out in the Division of Pediatric Otolaryngology-Head and Neck Surgery at Cincinnati Children's Hospital Medical Center. Chromosome 22q11.2 Deletion status was determined for all patients endoscopically diagnosed with anterior glottic webs between July 1998 and December 2000. Families of patients who tested positive for the Deletion were referred to the Cincinnati Children's Division of Human Genetics for additional evaluation and counseling. RESULTS: Eleven of 17 patients (65%) with anterior glottic webs were positive for Chromosome 22q11.2 Deletion. Of these 11 patients, 5 showed subtle clinical manifestations of velocardiofacial syndrome and underwent genetic testing due only to the presence of a web. All 11 patients were diagnosed with velocardiofacial syndrome. CONCLUSION: We strongly recommend that all patients diagnosed with anterior glottic webs undergo fluorescence in situ hybridization evaluation for this Chromosome Deletion.
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association of anterior glottic webs with velocardiofacial syndrome Chromosome 22q11 2 Deletion
Otolaryngology-Head and Neck Surgery, 2004Co-Authors: Christopher R Miyamoto, Alan F Rope, Robert J Hopkin, Sally R. Shott, Robin T. Cotton, Aliza P. Cohen, Michael J. RutterAbstract:OBJECTIVE: An association between anterior glottic webs and velocardiofacial syndrome (Chromosome 22q11.2 Deletion) has previously been noted in a number of case reports. Our objective was to determine if the presence of such webs warrants a high index of suspicion for this Chromosome Deletion. Study design and setting This study was carried out in the Division of Pediatric Otolaryngology-Head and Neck Surgery at Cincinnati Children's Hospital Medical Center. Chromosome 22q11.2 Deletion status was determined for all patients endoscopically diagnosed with anterior glottic webs between July 1998 and December 2000. Families of patients who tested positive for the Deletion were referred to the Cincinnati Children's Division of Human Genetics for additional evaluation and counseling. RESULTS: Eleven of 17 patients (65%) with anterior glottic webs were positive for Chromosome 22q11.2 Deletion. Of these 11 patients, 5 showed subtle clinical manifestations of velocardiofacial syndrome and underwent genetic testing due only to the presence of a web. All 11 patients were diagnosed with velocardiofacial syndrome. CONCLUSION: We strongly recommend that all patients diagnosed with anterior glottic webs undergo fluorescence in situ hybridization evaluation for this Chromosome Deletion.
Chad A Shaw - One of the best experts on this subject based on the ideXlab platform.
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chromosomal microarray analysis cma detects a large x Chromosome Deletion including fmr1 fmr2 and ids in a female patient with mental retardation
American Journal of Medical Genetics Part A, 2007Co-Authors: Frank J Probst, Elizabeth Roeder, Victoria B Enciso, Lance M Cooper, Patricia A Eng, Robert F Stratton, Craig A Chinault, Chad A Shaw, Reid V Sutton, Sau Wai CheungAbstract:Chromosomal microarray analysis (CMA) by array-based comparative genomic hybridization (CGH) is a new clinical test for the detection of well-characterized genomic disorders caused by chromosomal Deletions and duplications that result in gene copy number variation (CNV). This powerful assay detects an abnormality in approximately 7-9% of patients with various clinical phenotypes, including mental retardation. We report here on the results found in a 6-year-old girl with mildly dysmorphic facies, obesity, and marked developmental delay. CMA was requested and showed a heterozygous loss in copy number with clones derived from the genomic region cytogenetically defined as Xq27.3-Xq28. This loss was not cytogenetically visible but was seen on FISH analysis with clones from the region. Further studies confirmed a loss of one copy each of the FMR1, FMR2, and IDS genes (which are mutated in Fragile X syndrome, FRAXE syndrome, and Hunter syndrome, respectively). Skewed X-inactivation has been previously reported in girls with Deletions in this region and can lead to a combined Fragile X/Hunter syndrome phenotype in affected females. X-inactivation and iduronate 2-sulfatase (IDS) enzyme activity were therefore examined. X-inactivation was found to be random in the child's peripheral leukocytes, and IDS enzyme activity was approximately half of the normal value. This case demonstrates the utility of CMA both for detecting a submicroscopic chromosomal Deletion and for suggesting further testing that could possibly lead to therapeutic options for patients with developmental delay.
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chromosomal microarray analysis cma detects a large x Chromosome Deletion including fmr1 fmr2 and ids in a female patient with mental retardation
American Journal of Medical Genetics Part A, 2007Co-Authors: Frank J Probst, Elizabeth Roeder, Victoria B Enciso, Lance M Cooper, Robert F Stratton, Craig A Chinault, Zhishuo Ou, Jiangzhen Li, Yanghong Gu, Chad A ShawAbstract:Chromosomal microarray analysis (CMA) by array-based comparative genomic hybridization (CGH) is a new clinical test for the detection of well-characterized genomic disorders caused by chromosomal Deletions and duplications that result in gene copy number variation (CNV). This powerful assay detects an abnormality in approximately 7–9% of patients with various clinical phenotypes, including mental retardation. We report here on the results found in a 6-year-old girl with mildly dysmorphic facies, obesity, and marked developmental delay. CMA was requested and showed a heterozygous loss in copy number with clones derived from the genomic region cytogenetically defined as Xq27.3–Xq28. This loss was not cytogenetically visible but was seen on FISH analysis with clones from the region. Further studies confirmed a loss of one copy each of the FMR1, FMR2, and IDS genes (which are mutated in Fragile X syndrome, FRAXE syndrome, and Hunter syndrome, respectively). Skewed X-inactivation has been previously reported in girls with Deletions in this region and can lead to a combined Fragile X/Hunter syndrome phenotype in affected females. X-inactivation and iduronate 2-sulfatase (IDS) enzyme activity were therefore examined. X-inactivation was found to be random in the child's peripheral leukocytes, and IDS enzyme activity was approximately half of the normal value. This case demonstrates the utility of CMA both for detecting a submicroscopic chromosomal Deletion and for suggesting further testing that could possibly lead to therapeutic options for patients with developmental delay. © 2007 Wiley-Liss, Inc.