Search results for "genotype"
showing 10 items of 1725 documents
Bayesian model to detect phenotype-specific genes for copy number data
2012
Abstract Background An important question in genetic studies is to determine those genetic variants, in particular CNVs, that are specific to different groups of individuals. This could help in elucidating differences in disease predisposition and response to pharmaceutical treatments. We propose a Bayesian model designed to analyze thousands of copy number variants (CNVs) where only few of them are expected to be associated with a specific phenotype. Results The model is illustrated by analyzing three major human groups belonging to HapMap data. We also show how the model can be used to determine specific CNVs related to response to treatment in patients diagnosed with ovarian cancer. The …
Acromesomelic dysplasia Maroteaux type maps to human chromosome 9.
1998
SummaryAcromesomelic dysplasias are skeletal disorders that disproportionately affect the middle and distal segments of the appendicular skeleton. We report genetic mapping studies in four families with acromesomelic dysplasia Maroteaux type (AMDM), an autosomal recessive osteochondrodysplasia. A peak LOD score of 5.1 at recombination fraction 0 was obtained with fully informative markers on human chromosome 9. In three of the four families, the affected offspring are products of consanguineous marriages; if it is assumed that these affected offspring are homozygous by descent for the region containing the AMDM locus, a 6.9-cM AMDM candidate interval can be defined by markers D9S1853 and D9…
Restrictive mating by females on black grouse leks
2007
In bird species with pair bonds, extra-pair matings could allow females to choose genetically superior males. This is not needed in lekking species because female choice is not constrained by pairing opportunities. However, polyandry has been reported in most lekking species studied so far. Using 12 microsatellite loci, we determined the paternity of 135 broods of black grouse sampled between 2001 and 2005 (970 hatchlings and 811 adult birds genotyped). The paternity assignments were combined to lek observations to investigate the mating behaviour of black grouse females. About 10% of the matings seemed to take place with males displaying solitarily. Forty per cent of the copulations betwee…
Assessment of Susceptibility Risk Factors for ADHD in Imaging Genetic Studies
2019
Objective: ADHD consists of a count of symptoms that often presents heterogeneity due to overdispersion and excess of zeros. Statistical inference is usually based on a dichotomous outcome that is underpowered. The main goal of this study was to determine a suited probability distribution to analyze ADHD symptoms in Imaging Genetic studies. Method: We used two independent population samples of children to evaluate the consistency of the standard probability distributions based on count data for describing ADHD symptoms. Results: We showed that the zero-inflated negative binomial (ZINB) distribution provided the best power for modeling ADHD symptoms. ZINB reveals a genetic variant, rs273342…
Limited indirect fitness benefits of male group membership in a lekking species
2014
In group living species, individuals may gain the indirect fitness benefits characterizing kin selection when groups contain close relatives. However, tests of kin selection have primarily focused on cooperatively breeding and eusocial species, whereas its importance in other forms of group living remains to be fully understood. Lekking is a form of grouping where males display on small aggregated territories, which females then visit to mate. As females prefer larger aggregations, territorial males might gain indirect fitness benefits if their presence increases the fitness of close relatives. Previous studies have tested specific predictions of kin selection models using measures such as …
Female-biased dispersal alone can reduce the occurrence of inbreeding in black grouse (Tetrao tetrix)
2010
Although inbreeding depression and mechanisms for kin recognition have been described in natural bird populations, inbreeding avoidance through mate choice has rarely been reported suggesting that sex-biased dispersal is the main mechanism reducing the risks of inbreeding. However, a full understanding of the effect of dispersal on the occurrence of inbred matings requires estimating the inbreeding risks prior to dispersal. Combining pairwise relatedness measures and kinship assignments, we investigated in black grouse whether the observed occurrence of inbred matings was explained by active kin discrimination or by female-biased dispersal. In this large continuous population, copulations b…
Revisited Roles of Drosophila Female Pheromones
2005
All tests involved a pair of 5-day-old male and female (intact or decapitated) flies. Females were ‘homotypic’ (same species and strain as the tested male: D. melanogaster, Cs strain; D. mauritiana, 163.1 strain; D. simulans, Seychelles strain), ‘desat1 non-perfumed’ (D. melanogaster desat1 mutant), ‘perfumed’ (desat1 with transfer of Cs females pheromones), or ‘Cs’ (D. melanogaster control strain). Data shown are the frequencies of courtship (with both intact and decapitated females) and of mating (with intact females), within a 1 h observation period and were calculated from the total number of tested pairs (shown in brackets). D. mauritiana males courted (χ2 = 16.81, P < 0.001) and mated…
Tandem repeat structure of the duplicated Y-chromosomal STR locus DYS385 and frequency studies in the German and three Asian populations
1998
The Y-chromosomal short tandem repeat (STR) locus DYS385 can be typed using PCR amplification and separation of the resulting polymorphic fragments by non-denaturing high resolution polyacrylamide gel electrophoresis followed by silver staining. The PCR primers amplify a duplicated repeat sequence on the Y chromosome revealing a two-band pattern in male individuals. To determine the internal repeat structure as a basis for a consensus nomenclature, DNA sequence analysis was carried out after subcloning of PCR-amplified fragments revealing the uniform 4-bp repeat structure 'GAAA'. The shortest allele observed consisted of 10 repeat units thus providing the basis for the designation 'allele 1…
Role of cyclooxygenae-2 and 5-lypoxygenase polymorphisms in Alzheimer's disease in a population from northern Italy:implications for pharmacogenomics
2010
Alzheimer's disease (AD) is a neurodegenerative disorder clinically characterized by cognitive deficit with progressive worsening of memory. Recent data indicate that neurons, as well as other brain cells, can express enzymes such as cyclooxygenases (COXs) and 5-lipoxygenase (5-LO) which are considered important in inflammatory cells. Moreover, it has been demonstrated that COX-2 and 5-LO enzymes play a considerable role in the pathophysiology of AD. In order to assess the possible role of COX-2 and 5-LO single nucleotide polymorphisms (SNPs) in AD, we examined their distribution in 341 AD patients and 190 controls from Northern Italy. A significant difference was observed in the distributi…
Genotyping of sex hormone-related pathways in benign and malignant human prostate tissues: data of a preliminary study.
2011
Prostate cancer (PCa) is a major health issue in Westernized countries, representing a common cause of morbidity and mortality in the elderly male population. Endogenous sex steroids, along with environmental factors (notably diet) and host immune and inflammatory responses, are likely to cooperate in the pathogenesis of the disease. Based on the assumption that a complex endocrine–inflammatory-immune interaction is primarily implicated in human PCa, we have investigated the interplay between sex steroids and inflammation in development and growth of human PCa. To this end, we have assessed nine functional single nucleotide polymorphisms (SNP)s of five genes involved in sex hormone-related …