Search results for "zygosity"
showing 10 items of 200 documents
Data from: No inbreeding depression but increased sexual investment in highly inbred ant colonies
2012
Inbreeding can lead to the expression of deleterious recessive alleles and to a subsequent fitness reduction. In Hymenoptera, deleterious alleles are purged in haploid males moderating inbreeding costs. However, in these haplo-diploid species, inbreeding can result in the production of sterile diploid males. We investigated the effects of inbreeding on the individual and colony level in field colonies of the highly inbred ant Hypoponera opacior. In this species, outbreeding winged sexuals and nest-mating wingless sexuals mate during two separate reproductive periods. We show that regular sib-matings lead to high levels of homozygosity and the occasional production of diploid males, which sp…
Data from: Evidence for an association between post-fledging dispersal and microsatellite multilocus heterozygosity in a large population of greater …
2014
Dispersal can be divided into three stages: departure, transience and settlement. Despite the fact that theoretical studies have emphasized the importance of heterozygosity on dispersal strategies, empirical evidence of its effect on different stages of dispersal is lacking. Here, using multi-event capture-mark-recapture models, we show a negative association between microsatellite multilocus heterozygosity (MLH; 10 loci; n = 1023) and post-fledging dispersal propensity for greater flamingos, Phoenicopterus roseus, born in southern France. We propose that the negative effects of inbreeding depression affects competitive ability and therefore more homozygous individuals are more likely to di…
Heredity of interocular similarities in components of refraction: a population-based twin study among 66- to 79-year-old female twins.
2019
Purpose: To examine genetic influences on interocular similarities in ocular refraction and components of refraction among elderly female twins. Methods: Refraction was assessed in 94 monozygotic (MZ) and 74 dizygotic (DZ) female twins aged 66–78 years. Absolute values of interocular differences (Aniso variables) in spherical refraction (SR), refractive astigmatism (AST), spherical equivalent (SE), corneal refractive power (CR), corneal astigmatism (CAST), anterior chamber depth (ACD) and axial length (AL) were calculated. The differences between sisters in each of the Aniso variables were calculated and graded into two categories, best differentiating the groups, here isometropic and aniso…
Evidence for Three Distinct Classes of Phenotype Severity in Beta-Thalassaemia
2019
Background: Classification of phenotype severity in patients with beta-thalassaemia has so far relied mainly on expert opinion using parameters of genotype, clinical features at diagnosis, and transfusion requirement. The aim of this study was to use a large dataset of patients with beta-thalassaemia and evaluate a classification system based on onset variables agreed on by an international expert group, including age at diagnosis, at first transfusion, and at first iron chelation. Methods: A retrospective dataset of 7910 patients with homozygous or compound heterozygous beta-thalassaemia was used and subjected to cluster and classification analysis starting with the onset variables. Result…
Clinical and genetic characteristics of 21 Spanish patients with biallelic pathogenic SPG7 mutations.
2021
Spastic paraplegia type 7 (SPG7) is one of the most common hereditary spastic paraplegias. SPG7 mutations most often lead to spastic paraparesis (HSP) and/or hereditary cerebellar ataxia (HCA), frequently with mixed phenotypes. We sought to clinically and genetically characterize a Spanish cohort of SPG7 patients. Patients were recruited from our HCA and HSP cohorts. We identified twenty-one patients with biallelic pathogenic SPG7 mutations. Mean age at onset was 37.4 years (SD ± 14.3). The most frequent phenotype was spastic ataxia (57%), followed by pure spastic paraplegia (19%) and complex phenotypes (19%). Isolated patients presented with focal or multifocal dystonia, subclinical myopat…
Does δ-sarcoglycan-associated autosomal-dominant cardiomyopathy exist?
2009
In this study we clinically and genetically characterize a consanguineous family with a homozygous novel missense mutation in the delta-sarcoglycan gene and a second delta-sarcoglycan mutation that has previously been reported to cause severe autosomal-dominant dilated cardiomyopathy. We identified a novel missense mutation in exon 6 (p.A131P) of the delta-sarcoglycan gene, which in a homozygous state leads to the clinical picture of a limb girdle muscular dystrophy. In four heterozygous carriers for the mutation, aged 3-64 years, a second sequence variant in exon 6 (p.S151A) of the delta-sarcoglycan gene was detected on the other allele. This second missense change had previously been repo…
Abnormalities in alpha-dystroglycan expression in MDC1C and LGMD2I muscular dystrophies
2004
We recently identified mutations in the fukutin related protein (FKRP) gene in patients with congenital muscular dystrophy type 1C (MDC1C) and limb girdle muscular dystrophy type 2I (LGMD2I). The sarcolemma of these patients typically displays an immunocytochemical reduction of alpha-dystroglycan. In this report we extend these observations and report a clear correlation between the residual expression of alpha-dystroglycan and the phenotype. Three broad categories were identified. Patients at the severe end of the clinical spectrum (MDC1C) were compound heterozygote between a null allele and a missense mutation or carried two missense mutations and displayed a profound depletion of alpha-d…
Relationship between inbreeding and milk production traits in two Italian dairy sheep breeds.
2022
The effects of inbreeding in livestock species breeds have been well documented and they have a negative impact on profitability. The objective of this study was to evaluate the levels of inbreeding in Sarda (SAR, n = 785) and Valle del Belice (VdB, n = 473) dairy sheep breeds and their impact on milk production traits. Two inbreeding coefficients (F) were estimated: using pedigree (FPED), or runs of homozygosity (ROH; FROH) at different minimum ROH lengths and different ROH classes. After the quality control, 38,779 single nucleotide polymorphisms remained for further analyses. A mixed-linear model was used to evaluate the impact of inbreeding coefficients on production traits within each …
Analysis of runs of homozygosity of cattle living in different climate zones
2023
Abstract Aim of this study was to analyze the distribution and characteristics of runs of homozygosity in Bos taurus taurus and Bos taurus indicus breeds, as well as their crosses, farmed all around the world. With this aim in view, we used single-nucleotide polymorphisms (SNP) genotypes for 3,263 cattle belonging to 204 different breeds. After quality control, 23,311 SNPs were retained for the analysis. Animals were divided into seven different groups: 1) continental taurus, 2) temperate taurus, 3) temperate indicus, 4) temperate composite, 5) tropical taurus, 6) tropical indicus, and 7) tropical composite. The climatic zones were created according to the latitude of the breeds’ country of…
Age- and quality-dependent DNA methylation correlate with melanin-based coloration in a wild bird
2018
Abstract Secondary sexual trait expression can be influenced by fixed individual factors (such as genetic quality) as well as by dynamic factors (such as age and environmentally induced gene expression) that may be associated with variation in condition or quality. In particular, melanin‐based traits are known to relate to condition and there is a well‐characterized genetic pathway underpinning their expression. However, the mechanisms linking variable trait expression to genetic quality remain unclear. One plausible mechanism is that genetic quality could influence trait expression via differential methylation and differential gene expression. We therefore conducted a pilot study examining…