1,394 research outputs found
The impact of different concentrations of a pyrethroid insecticide on the cyclic gas exchange cycles on bumble bees
contribution to session II
Bumblebees and other bee specie
Regular periods of abdominal contractions recorded from larvae of the bumblebee, Bombus terrestris (Hymenoptera: Apidae)
Whole-exome sequencing identifies de novo mutation in the COL1A1 gene to underlie the severe osteogenesis imperfecta
Background
Osteogenesis imperfecta (OI) comprises a clinically and genetically heterogeneous group of connective tissue disorders, characterized by low bone mass, increased bone fragility, and blue-gray eye sclera. OI often results from missense mutations in one of the conserved glycine residues present in the Gly-X-Y sequence repeats of the triple helical region of the collagen type I α chain, which is encoded by the COL1A1 gene. The aim of the present study is to describe the phenotype of OI II patient and a novel mutation, causing current phenotype.
Results
We report an undescribed de novo COL1A1 mutation in a patient affected by severe OI. After performing the whole-exome sequencing in a case parentâchild trio, we identified a novel heterozygous c.2317Gâ>âT missense mutation in the COL1A1 gene, which leads to p.Gly773Cys transversion in the triple helical domain of the collagen type I α chain. The presence of the missense mutation was confirmed with the Sanger sequencing.
Conclusions
Hereby, we report a novel mutation in the COL1A1 gene causing severe, life threatening OI and indicate the role of de novo mutation in the pathogenesis of rare familial diseases. Our study underlines the importance of exome sequencing in disease gene discovery for families where conventional genetic testing does not give conclusive evidence
Evidence of Early-Stage Selection on EPAS1 and GPR126 Genes in Andean High Altitude Populations.
The aim of this study is to identify genetic variants that harbour signatures of recent positive selection and may facilitate physiological adaptations to hypobaric hypoxia. To achieve this, we conducted whole genome sequencing and lung function tests in 19 Argentinean highlanders (>3500âm) comparing them to 16 Native American lowlanders. We developed a new statistical procedure using a combination of population branch statistics (PBS) and number of segregating sites by length (nSL) to detect beneficial alleles that arose since the settlement of the Andes and are currently present in 15-50% of the population. We identified two missense variants as significant targets of selection. One of these variants, located within the GPR126 gene, has been previously associated with the forced expiratory volume/forced vital capacity ratio. The other novel missense variant mapped to the EPAS1 gene encoding the hypoxia inducible factor 2α. EPAS1 is known to be the major selection candidate gene in Tibetans. The derived allele of GPR126 is associated with lung function in our sample of highlanders (pâ<â0.05). These variants may contribute to the physiological adaptations to hypobaric hypoxia, possibly by altering lung function. The new statistical approach might be a useful tool to detect selected variants in population studies
Genome-wide analysis of Corsican population reveals a close affinity with Northern and Central Italy
Despite being the fourth largest island in the Mediterranean basin, the genetic variation of Corsica has not been explored as exhaustively as Sardinia, which is situated only 11 km South. However, it is likely that the populations of the two islands shared, at least in part, similar demographic histories. Moreover, the relative small size of the Corsica may have caused genetic isolation, which, in turn, might be relevant under medical and translational perspectives. Here we analysed genome wide data of 16 Corsicans, and integrated with newly (33 individuals) and previously generated samples from West Eurasia and North Africa. Allele frequency, haplotype-based, and ancient genome analyses suggest that although Sardinia and Corsica may have witnessed similar isolation and migration events, the latter is genetically closer to populations from continental Europe, such as Northern and Central Italians
Genome-wide analysis of nuclear magnetic resonance metabolites revealed parent-of-origin effect on triglycerides in medium very low-density lipoprotein in PTPRD gene
The aim of the study was to explore the parent-of-origin effects (POEs) on a range of human nuclear magnetic resonance metabolites. Materials & methods: We search for POEs in 14,815 unrelated individuals from Estonian and Finnish cohorts using POE method for the genotype data imputed with 1000 G reference panel and 82 nuclear magnetic resonance metabolites. Results: Meta-analysis revealed the evidence of POE for the variant rs1412727 in PTPRD gene for the metabolite: triglycerides in medium very low-density lipoprotein. No POEs were detected for genetic variants that were previously known to have main effect on circulating metabolites. Conclusion: We demonstrated possibility to detect POEs for human metabolites, but the POEs are weak, and therefore it is hard to detect those using currently available sample sizes.Peer reviewe
Population distribution and ancestry of the cancer protective MDM2 SNP285 (rs117039649)
Cataloged from PDF version of article.The MDM2 promoter SNP285C is located on the SNP309G allele. While SNP309G enhances Sp1 transcription factor binding and MDM2 transcription, SNP285C antagonizes Sp1 binding and reduces the risk of breast-, ovary- and endometrial cancer. Assessing SNP285 and 309 genotypes across 25 different ethnic populations (>10.000 individuals), the incidence of SNP285C was 6-8% across European populations except for Finns (1.2%) and Saami (0.3%). The incidence decreased towards the Middle-East and Eastern Russia, and SNP285C was absent among Han Chinese, Mongolians and African Americans. Interhaplotype variation analyses estimated SNP285C to have originated about 14,700 years ago (95% CI: 8,300 - 33,300). Both this estimate and the geographical distribution suggest SNP285C to have arisen after the separation between Caucasians and modern day East Asians (17,000 - 40,000 years ago). We observed a strong inverse correlation (r = -0.805; p < 0.001) between the percentage of SNP309G alleles harboring SNP285C and the MAF for SNP309G itself across different populations suggesting selection and environmental adaptation with respect to MDM2 expression in recent human evolution. In conclusion, we found SNP285C to be a pan-Caucasian variant. Ethnic variation regarding distribution of SNP285C needs to be taken into account when assessing the impact of MDM2 SNPs on cancer risk
Analysis of SNP profiles in patients with major depressive disorder
The present study focused on 91 single-nucleotide polymorphisms (SNPs) in 21 candidate genes to find associations with major depressive disorder (MDD). In total, 160 healthy controls and 177 patients with MDD were studied. We applied arrayed primer extension (APEX) based genotyping technology followed by association and haplotype analysis. SNPs in CCKAR, DRD1, DRD2, and HTR2C genes showed nominally significant associations with MDD. None of these associations remained significant after adjustment for multiple testing. Haplotype analysis revealed CCKAR haplotypes to be associated with MDD (global p=0.004). More precisely, we found the GAGT haplotype to be associated with increased risk for MDD (OR 7.42, 95% CI 2.13â25.85, p=0.002). This haplotype effect remained significant after Bonferroni correction (p=0.04 after Bonferroni's adjustment). Altogether we were able to find some nominal associations, but due to small sample size these results should be taken as exploratory. However, the effect of GAGT haplotype on the CCKAR gene may be considered as increasing the risk for MDD
An invasive Haemophilus influenzae serotype b infection in an Anglo-Saxon plague victim.
BACKGROUND: The human pathogen Haemophilus influenzae was the main cause of bacterial meningitis in children and a major cause of worldwide infant mortality before the introduction of a vaccine in the 1980s. Although the occurrence of serotype b (Hib), the most virulent type of H. influenzae, has since decreased, reports of infections with other serotypes and non-typeable strains are on the rise. While non-typeable strains have been studied in-depth, very little is known of the pathogen's evolutionary history, and no genomes dating prior to 1940 were available. RESULTS: We describe a Hib genome isolated from a 6-year-old Anglo-Saxon plague victim, from approximately 540 to 550âCE, Edix Hill, England, showing signs of invasive infection on its skeleton. We find that the genome clusters in phylogenetic division II with Hib strain NCTC8468, which also caused invasive disease. While the virulence profile of our genome was distinct, its genomic similarity to NCTC8468 points to mostly clonal evolution of the clade since the 6th century. We also reconstruct a partial Yersinia pestis genome, which is likely identical to a published first plague pandemic genome of Edix Hill. CONCLUSIONS: Our study presents the earliest genomic evidence for H. influenzae, points to the potential presence of larger genomic diversity in the phylogenetic division II serotype b clade in the past, and allows the first insights into the evolutionary history of this major human pathogen. The identification of both plague and Hib opens questions on the effect of plague in immunocompromised individuals already affected by infectious diseases
Development and validation of two SCORE-based cardiovascular risk prediction models for Eastern Europe: a multicohort study.
AIMS: Cardiovascular disease (CVD) risk prediction models are used in Western European countries, but less so in Eastern European countries where rates of CVD can be two to four times higher. We recalibrated the SCORE prediction model for three Eastern European countries and evaluated the impact of adding seven behavioural and psychosocial risk factors to the model. METHODS AND RESULTS: We developed and validated models using data from the prospective HAPIEE cohort study with 14â598 participants from Russia, Poland, and the Czech Republic (derivation cohort, median follow-up 7.2 years, 338 fatal CVD cases) and Estonian Biobank data with 4632 participants (validation cohort, median follow-up 8.3 years, 91 fatal CVD cases). The first model (recalibrated SCORE) used the same risk factors as in the SCORE model. The second model (HAPIEE SCORE) added education, employment, marital status, depression, body mass index, physical inactivity, and antihypertensive use. Discrimination of the original SCORE model (C-statistic 0.78 in the derivation and 0.83 in the validation cohorts) was improved in recalibrated SCORE (0.82 and 0.85) and HAPIEE SCORE (0.84 and 0.87) models. After dichotomizing risk at the clinically meaningful threshold of 5%, and when comparing the final HAPIEE SCORE model against the original SCORE model, the net reclassification improvement was 0.07 [95% confidence interval (CI) 0.02-0.11] in the derivation cohort and 0.14 (95% CI 0.04-0.25) in the validation cohort. CONCLUSION: Our recalibrated SCORE may be more appropriate than the conventional SCORE for some Eastern European populations. The addition of seven quick, non-invasive, and cheap predictors further improved prediction accuracy
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