Search results for "Chromosome Inversion"
showing 9 items of 19 documents
On the power and the systematic biases of the detection of chromosomal inversions by paired-end genome sequencing
2013
One of the most used techniques to study structural variation at a genome level is paired-end mapping (PEM). PEM has the advantage of being able to detect balanced events, such as inversions and translocations. However, inversions are still quite difficult to predict reliably, especially from high-throughput sequencing data. We simulated realistic PEM experiments with different combinations of read and library fragment lengths, including sequencing errors and meaningful base-qualities, to quantify and track down the origin of false positives and negatives along sequencing, mapping, and downstream analysis. We show that PEM is very appropriate to detect a wide range of inversions, even with …
The copy number variant involving part of the α7 nicotinic receptor gene contains a polymorphic inversion.
2008
The alpha7 nicotinic acetylcholine receptor gene (CHRNA7) is located at 15q13-q14 in a region that is strongly linked to the P50 sensory gating deficit, an endophenotype of schizophrenia and bipolar disorder. Part of the gene is a copy number variant, due to a duplication of exons 5-10 and 3' sequence in CHRFAM7A, which is present in many but not all humans. Maps of this region show that the two genes are in opposite orientation in the individual mainly represented in the public access human DNA sequence database (Build 36), suggesting that an inversion had occurred since the duplication. We have used fluorescent in situ hybridization to investigate this putative inversion. Analysis of inte…
Mitochondrial DNA evolution in experimental populations of Drosophila subobscura.
1990
When two mitochondrial DNA (mtDNA) haplotypes of Drosophila subobscura compete in experimental populations with discrete generations, one or the other approaches fixation, depending on the nuclear background with which they are associated. The approach to fixation, however, is strongly dependent on the effective number of females in the population, Nf. Whether or not the ultimate fate of a given mtDNA haplotype is determined by random genetic drift depends on Nf as well as on the relative fitnesses. Our experimental results show that the mtDNA polymorphisms observed in natural populations are affected by interactions among nuclear polymorphisms, random genetic drift, and direct selection on…
Inherited pericentric inversion of human chromosome 5.
1983
Une inversion pericentrique heterozygote du chromosome 5 a ete decouverte dans les cellules de la moelle osseuse et dans les lymphocytes peripheriques stimules par le phytohemagglutinine d'une femme de 75 ans atteinte de myelofibrose et de metaplasie myeloide. L'inversion etait presente dans 100% des metaphases etudiees. Les points de cessure du chromosome 5 etaient localises en k15 et q10. Une etude de la famille est presentee
Genomic structure and paralogous regions of the inversion breakpoint occurring between human chromosome 3p12.3 and orangutan chromosome 2.
2003
Intrachromosomal duplications play a significant role in human genome pathology and evolution. To better understand the molecular basis of evolutionary chromosome rearrangements, we performed molecular cytogenetic and sequence analyses of the breakpoint region that distinguishes human chromosome 3p12.3 and orangutan chromosome 2. FISH with region-specific BAC clones demonstrated that the breakpoint-flanking sequences are duplicated intrachromosomally on orangutan 2 and human 3q21 as well as at many pericentromeric and subtelomeric sites throughout the genomes. Breakage and rearrangement of the human 3p12.3-homologous region in the orangutan lineage were associated with a partial loss of dup…
A microsatellite linkage map forDrosophila montanashows large variation in recombination rates, and a courtship song trait maps to an area of low rec…
2009
Current advances in genetic analysis are opening up our knowledge of the genetics of species differences, but challenges remain, particularly for out-bred natural populations. We constructed a microsatellite-based linkage map for two out-bred lines of Drosophila montana derived from divergent populations by taking advantage of the Drosophila virilis genome and available cytological maps of both species. Although the placement of markers was quite consistent with cytological predictions, the map indicated large heterogeneity in recombination rates along chromosomes. We also performed a quantitative trait locus (QTL) analysis on a courtship song character (carrier frequency), which differs be…
Chromosomal polymorphism and patterns of viability in natural populations of Drosophila melanogaster from cellar and vineyard.
1991
Two neighbouring natural populations of Drosophila melanogaster have been analysed, one from a cellar habitat and the other from a vineyard outside. An extensive study of inversion polymorphism in the two populations has been carried out. Furthermore, the relationship between inversion polymorphism and the viability of the second chromosome has been studied. The data regarding the total frequency of inversion-carrying chromosomes indicate a lower frequency in the cellar population than in the vineyard population. Some possibilities that could explain the behaviour of the chromosomes from the cellar in relation to the peculiar environment of this habitat are discussed. New endemic inversions…
The banding pattern of polytene chromosomes of Drosophila guanche compared with that of D. subobscura.
1987
A detailed map of the salivary gland chromosomes of Drosophila guanche is presented and compared to the standard gene arrangements of D. subobscura. Generally, the polytene chromosomc banding patterns of the two species show a high degrce of homology. Only Segment I of the sex chromosome (Chromosome A) shows marked differences. The banding pattern proposed for this segment in D. guanche could have originated from a cluster of overlapping inversions including A1 arrangement.
A girl with an atypical form of ataxia telangiectasia and an additional de novo 3.14Mb microduplication in region 19q12
2011
A 9-year-old girl born to healthy parents showed manifestations suggestive of ataxia telangiectasia (AT), such as short stature, sudden short bouts of horizontal and rotary nystagmus, a weak and dysarthric voice, rolling gait, unstable posture, and atactic movements. She did not show several cardinal features typical of AT such as frequent, severe infections of the respiratory tract. In contrast, she showed symptoms not generally related to AT, including microcephaly, profound motor and mental retardation, small hands and feet, severely and progressively reduced muscle tone with slackly protruding abdomen and undue drooling, excess fat on her upper arms, and severe oligoarthritis. A cranial…