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Inversion Polymorphism (inversion + polymorphism)
Selected AbstractsLong-term changes in the chromosomal inversion polymorphism of Drosophila subobscura.JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 3 2004Abstract The chromosomal polymorphism of 13 European populations of Drosophila subobscura has been compared with that of the same populations collected 15,35 years ago. The chromosomal polymorphism of the old populations differs significantly from that of the new populations, mainly for chromosomes U and O. There is a very good agreement between the geographical space and the genetic space as shown by a graphical representation of the 26 statistical populations (13 old and 13 new) obtained by a principal coordinate analysis. This reflects both the existence of significant latitudinal clines for the frequencies of some chromosomal arrangements in the old and new samples and systematic changes that have taken place in these populations during the period that elapsed between the two surveys. An increase in the frequency of those arrangements typical of southern latitudes and a decrease for those common in northern latitudes is observed in all populations , Mediterranean, Atlantic and Central European. Furthermore, the genetic distances of the new populations to a southern population of reference have decreased in comparison with those of the old populations. These changes could be the result of climatic factors that are correlated with latitude. In particular, the assumption that global warming is responsible for all the changes observed appears rather likely. Whether these systematic changes of the chromosomal polymorphism are a consequence of local adaptations or have been produced by migration from the south remains an open question. Zusamennfassung Der gegenwärtige chromosomale Inversionspolymorphismus in 13 europäischen Populationen von Drosophila subobscura wurde mit dem Zustand in denselben Populationen verglichen, die vor 15 bis 35 Jahren untersucht worden waren. Der Chromosomenpolymorphismus der ,,alten'' Populationen unterscheidet sich signifikant von dem der ,,neuen'' Populationen, besonders für die Chromosomen U und O. Eine sehr gute Übereinstimmung zeigt sich zwischen der geographischen Komponente und der genetischen Komponente bei einer graphischen Darstellung der 26 Populationen (13 alte und 13 neue Populationen) durch eine Koordinatenanalyse. Das spiegelt beides wider, die Existenz von signifikanten breitenabhängigen Klinen in der Häufigkeit einiger chromosomaler Strukturtypen in den alten und den neuen Populationen, aber auch die systematischen Änderungen, die sich bei diesen Populationen im Laufe der Zeit zwischen den beiden Untersuchungen ereignet haben. Eine Zunahme in den Häufigkeiten jener Chromosomenstrukturen, die typisch für südliche Breiten sind, und eine Abnahme solcher Strukturen, die häufig in nördliche Breiten sind, konnte beobachtet werden - in den mediterranen, den atlantischen und den mitteleuropäischen Populationen in der gleichen Weise. Außerdem haben die genetischen Distanzen der neuen Populationen zu einer südlichen Referenzpopulation im Vergleich zu denen der alten Populationen abgenommen. Diese Veränderungen wurden vermutlich von klimatischen Faktoren bestimmt, die mit der geographischen Breite korreliert sind. Insbesonders erscheint die Annahme, daß die globale Erwärmung für die Veränderungen des Chromosomenpolymorphismus dafür verantwortlich ist, ziemlich wahrscheinlich. Ob diese systematischen Transformationen des Chromosomenpolymorphismus ein Konsequenz lokaler Anpassungen oder auf Migration aus dem Süden zurückzuführen sind, bleibt eine offene Frage. [source] Chromosomal inversion polymorphism of Drosophila subobscura from south-eastern part of EuropeJOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 4 2002G. Zivanovic Abstract Five Drosophila subobscura populations from south-eastern Europe were investigated with respect to chromosomal inversion polymorphism. They belong to central European populations and their gene arrangement frequencies are in accordance with latitudinal variation observed in this species. The new complex gene arrangement A2+8+9, found in one of the populations analysed, may be specific for the southern Balkan refugium. A general tendency of gene arrangement frequencies to exhibit some southern characteristics was found for some of the autosomal standard arrangements. Zusammenfassung Fünf Populationen von Drosophila suboscura aus dem Süwesten von Europa wurden hinsichtlich ihres chromosomalen Inversionspolymorphismus untersucht. Sie erweisen sich als zu den mitteleuropäischen Populationen gehörig und die Häufigkeiten der chromosomalen Inversionsstrukturen stimmen mit den breitenabhängigen Häufigkeitsklinen, die in dieser Art beobachtet werden, überein. Ein neuer komplexer Strukturtyp, A2+8+9, der in einer der untersuchten Populationen gefunden wurde, scheint für das Refugium im südlichen Balkan spezifisch zu sein. Eine allgemeine Tendenz der Häufigkeiten der Strukturtypen, sich in Richtung mehr südlichere Eigenschaften zu verändern, wurde für einige der Standardstrukturtypen der Autosomen gefunden. [source] Inversion of the Williams syndrome region is a common polymorphism found more frequently in parents of children with Williams syndrome,AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2010Holly H. Hobart Abstract Williams syndrome (WS) is a multisystem disorder caused by deletion of about 1.55,Mb of DNA (including 26 genes) on chromosome 7q11.23, a region predisposed to recombination due to its genomic structure. Deletion of the Williams syndrome chromosome region (WSCR) occurs sporadically. To better define chance for familial recurrence and to investigate the prevalence of genomic rearrangements of the region, 257 children with WS and their parents were studied. We determined deletion size in probands by metaphase FISH, parent-of-origin of the deleted chromosome by molecular genetic methods, and inversion status of the WSCR in both parents by interphase FISH. The frequency of WSCR inversion in the transmitting parent group was 24.9%. In contrast, the rate of inversion in the non-transmitting parent group (a reasonable estimate of the rate in the general population) was 5.8%. There were no significant gender differences with respect to parent-of-origin for the deleted chromosome or the incidence of the inversion polymorphism. There was no difference in the rate of spontaneous abortion for mothers heterozygous for the WSCR inversion relative to mothers without the inversion. We calculate that for a parent heterozygous for a WSCR inversion, the chance to have a child with WS is about 1 in 1,750, in contrast to the 1 in 9,500 chance for a parent without an inversion. © 2010 Wiley-Liss, Inc. [source] Association analysis of MAPT H1 haplotype and subhaplotypes in Parkinson's diseaseANNALS OF NEUROLOGY, Issue 2 2007Cyrus P. Zabetian MD Objective An inversion polymorphism of approximately 900kb on chromosome 17q21, which includes the microtubule-associated protein tau (MAPT) gene defines two haplotype clades, H1 and H2. Several small case,control studies have observed a marginally significant excess of the H1/H1 diplotype among patients with Parkinson's disease (PD), and one reported refining the association to a region spanning exons 1 to 4 of MAPT. We sought to replicate these findings. Methods We genotyped 1,762 PD patients and 2,010 control subjects for a single nucleotide polymorphism (SNP) that differentiates the H1 and H2 clades. We also analyzed four SNPs that define subhaplotypes within H1 previously reported to associate with PD or other neurodegenerative disorders. Results After adjusting for age, sex, and site, we observed a robust association between the H1/H1 diplotype and PD risk (odds ratio for H1/H1 vs H1/H2 and H2/H2, 1.46; 95% confidence interval, 1.25,1.69; p = 8 × 10,7). The effect was evident in both familial and sporadic subgroups, men and women, and early- and late-onset disease. Within H1/H1 individuals, there was no significant difference between cases and control subjects in the overall frequency distribution of H1 subhaplotypes. Interpretation Our data provide strong evidence that the H1 clade, which contains MAPT and several other genes, is a risk factor for PD. However, attributing this finding to variants within a specific region of MAPT is premature. Thorough fine-mapping of the H1 clade in large numbers of individuals is now needed to identify the underlying functional variant(s) that alter susceptibility for PD. Ann Neurol 2007 [source] | ||||||||||