977 research outputs found

    Y-chromosome Short Tandem Repeat DYS458.2 Non-consensus Alleles Occur Independently in Both Binary Haplogroups J1-M267 and R1b3-M405

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    Cilj: Odrediti haploskupinsku osnovu “non-consensus” kratkih udvojenih sljedova (engl., short tandem repeat, STR) alela DYS458.2 na kromosomu Y i procijeniti njihov filogenetski podustroj i učestalost u reprezentativnim uzorcima sa Srednjega Istoka, Europe i Pakistana. Postupci: Molekularna karakterizacija povezanosti i konstrukcija haplotipova provedena je kombinacijom dvaju pristupa – analizom binarnog polimorfizma koji definira haploskupinu kromosoma Y i analizom do 37 lokusa STR, uključujući i DYS388. Za utvrđivanje povezanosti kromosoma Y koji sadrže slijed DYS458.2, rabljeno je sekvencioniranje DNA lokusa DYS458 i mrežna analiza udaljenosti od medijana. Rezultati Pokazali smo da je novi alel DYS458.2 nastao nezavisno na najmanje dvije osnove binarnih haploskupina, a možda i na trećoj. U svim haploskupinama kromosoma J1 koje su pregledane, uključivši i njegove poznate a malobrojne pod-haploskupine, nađen je fiksan dužinski uzorak parcijalnoga alela. U alternativnom M405 povezanom s R1b3 definiranoj pod-haploskupini nađene su i DYS458.0 i DYS458.2 alelne klase. Pojedinačni kromosom također se mogao svrstati u R1b3-M269*(xM405) klasu. Fizički smještaj djelomične nsercije/delecije u normalnom slijedu tetramera jasno se razlikovao u kontekstu svake haploskupine. Zaključak: Iako neobični aleli DYS458.2 pružaju korisne informacije, prilikom zaključivanja o haploskupinskoj osnovi i uobičajenom nasljeđivanju potrebne su dodatne informacije o drugim vezanim polimorfnim lokusima.Aim: To determine the human Y-chromosome haplogroup backgrounds of non-consensus DYS458.2 short tandem repeat alleles and evaluate their phylogenetic substructure and frequency in representative samples from the Middle East, Europe, and Pakistan. Methods: Molecular characterization of lineages was achieved using a combination of Y-chromosome haplogroup defining binary polymorphisms and up to 37 short tandem repeat loci, including DYS388 to construct haplotypes. DNA sequencing of the DYS458 locus and median-joining network analyses were used to evaluate Y-chromosome lineages displaying the DYS458.2 motif. Results: We showed that the DYS458.2 allelic innovation arose independently on at least two distinctive binary haplogroup backgrounds and possibly a third as well. The partial allele length pattern was fixed in all haplogroup J1 chromosomes examined, including its known rare sub-haplogroups. Within the alternative R1b3 associated M405 defined sub-haplogroup, both DYS458.0 and DYS458.2 allele classes occurred. A single chromosome also allocated to the R1b3-M269*(xM405) classification. The physical position of the partial insertion/deletion occurrence within the normal tetramer tract differed distinctly in each haplogroup context. Conclusions: While unusual DYS458.2 alleles are informative, additional information for other linked polymorphic loci is required when using such non-conforming alleles to infer haplogroup background and common ancestry

    The Role of Geography in Human Adaptation

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    Various observations argue for a role of adaptation in recent human evolution, including results from genome-wide studies and analyses of selection signals at candidate genes. Here, we use genome-wide SNP data from the HapMap and CEPH-Human Genome Diversity Panel samples to study the geographic distributions of putatively selected alleles at a range of geographic scales. We find that the average allele frequency divergence is highly predictive of the most extreme FST values across the whole genome. On a broad scale, the geographic distribution of putatively selected alleles almost invariably conforms to population clusters identified using randomly chosen genetic markers. Given this structure, there are surprisingly few fixed or nearly fixed differences between human populations. Among the nearly fixed differences that do exist, nearly all are due to fixation events that occurred outside of Africa, and most appear in East Asia. These patterns suggest that selection is often weak enough that neutral processes—especially population history, migration, and drift—exert powerful influences over the fate and geographic distribution of selected alleles

    Increased Birth Weight Associated with Regular Pre-Pregnancy Deworming and Weekly Iron-Folic Acid Supplementation for Vietnamese Women

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    Low birth weight is an important risk factor for neonatal and infant morbidity and mortality and may impact on growth and development. Maternal iron deficiency anaemia contributes to intrauterine growth restriction and low birth weight. Hookworm infections and an iron-depleted diet may lead to iron deficiency anaemia, and both are common in many developing countries. A pilot program of deworming and weekly iron-folic acid supplementation for non-pregnant women aiming to prevent iron deficiency was implemented in northern Vietnam. We compared the birth weight of babies born to women who had had access to the intervention to babies born in districts where the intervention had not been implemented. The mean birth weight of the intervention districts' babies was 124 g more than the control districts' babies; the prevalence of low birth weight was also reduced. These results suggest that providing women with deworming and weekly iron-folic acid supplements before pregnancy is associated with increased birth weight in rural Vietnam. This intervention was provided as a health system integrated program which could be replicated in other at-risk rural areas. If so it could increase the impact of prenatal and antenatal programs, improving the health of both women and newborns

    Saethre-Chotzen syndrome : cranofacial anomalies caused by genetic changes in the TWIST gene

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    In this thesis, one of the most frequently occurring and most variable craniosynostosis syndromes was investigated; Saethre-Chotzen syndrome. Craniosynostosis is the premature obliteration of cranial sutures in the developing embryo. It can also occur in the first few months of life. Saethre-Chotzen syndrome is, besides craniosynostosis, characterized by specific facial and limb abnormalities, of which the most frequently reported are ptosis, prominent crus helicis, cutaneous syndactyly of digit 2 and 3 on both hands and feet, and broad halluces. Saethre-Chotzen syndrome has been linked to the TWIST gene on chromosome 7p21.1. Mutations in and variably sized deletions of this gene can be found in patients with clinical features of Saethre-Chotzen syndrome. The latter, TWIST deletions, often also include part of the surrounding chromosome 7p and are reported to be associated with mental retardation. In Saethre-Chotzen patients, in whom neither a mutation nor a deletion of TWIST had been found, the FGFR3 P250R mutation was in some cases detected. This mutation has specifically been linked to Muenke syndrome that is characterized by unior bicoronal synostosis and slight facial dysmorphology. However, a Saethre-Chotzen like phenotype can also result from this mutation. Because of the possible overlap of Saethre-Chotzen with Muenke syndrome, these syndromes were studied in order to provide clinical criteria that discriminate between the two (chapter 4). Many phenotypic features occur in both syndromes. In addition, although unicoronal synostosis occurs slightly more frequently in Muenke syndrome, unicoronal and bicoronal synostosis are seen in both syndromes. The discrimination between Saethre-Chotzen and Muenke is often not made easily and the associated genes, TWIST and FGFR3, respectively, are simultaneously tested for pathogenic m

    Search for resonant WZ production in the fully leptonic final state in proton–proton collisions at √s=13 TeV with the ATLAS detector

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    Measurement of exclusive pion pair production in proton–proton collisions at √s=7 TeV with the ATLAS detector

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    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH < 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 < κλ < 6.9 and −0.5 < κ2V < 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions
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