38 research outputs found
Cryptic species and parallel genetic structuring in Lethrinid fish:Implications for conservation and management in the southwest Indian Ocean
Analysis of genetic variation can provide insights into ecological and evolutionary diversification which, for commercially harvested species, can also be relevant to the implementation of spatial management strategies and sustainability. In comparison with other marine biodiversity hot spots, there has been less genetic research on the fauna of the southwest Indian Ocean (SWIO). This is epitomized by the lack of information for lethrinid fish, which support socioeconomically important fisheries in the region. This study combines comparative phylogeographic and population genetic analyses with ecological niche modeling to investigate historical and contemporary population dynamics of two species of emperor fish (Lethrinus mahsena and Lethrinus harak) across the SWIO. Both species shared similarly shallow phylogeographic patterns and modeled historical (LGM) habitat occupancies. For both species, allele frequency and kinship analyses of microsatellite variation revealed highly significant structure with no clear geographical pattern and nonrandom genetic relatedness among individuals within samples. The genetic patterns for both species indicate recurrent processes within the region that prevent genetic mixing, at least on timescales of interest to fishery managers, and the potential roles of recruitment variability and population isolation are discussed in light of biological and environmental information. This consistency in both historical and recurrent population processes indicates that the use of model species may be valuable in management initiatives with finite resources to predict population structure, at least in cases wherein biogeographic and ecological differences between taxa are minimized. Paradoxically, mtDNA sequencing and microsatellite analysis of samples from the Seychelles revealed a potential cryptic species occurring in sympatry with, and seemingly morphologically identical to, L. mahsena. BLAST results point to the likely misidentification of species and incongruence between voucher specimens, DNA barcodes, and taxonomy within the group, which highlights the utility and necessity of genetic approaches to characterize baseline biodiversity in the region before such model-based methods are employedpublishersversionPeer reviewe
Barriers to help-seeking among music festival attendees in New South Wales, Australia
Introduction: Prompt help-seeking behaviour by music festival attendees can reduce risks associated with drug use; however, little is known about perceived barriers to help-seeking when experiencing or witnessing illness at music festivals. We explored potential barriers and their association with festivalgoer characteristics. Methods: We conducted an on-site cross-sectional survey of attendees at New South Wales music festivals in 2019/2020. Perceived barriers to help-seeking in the hypothetical event of the respondent or a friend becoming unwell at the festival were assessed, and regression analyses were conducted to identify characteristics associated with these barriers. Results: Across six festivals, 1229 people were surveyed and four-fifths (83.2%) reported ≥1 barrier: 32.7% fear of getting in trouble with the police, 20.6% not knowing where to find help, 17.2% not knowing how unwell someone might be and 15.3% concern about friends or relatives finding out. In multivariable analyses, people of diverse sexuality and people using drugs that day had greater odds of reporting fear of trouble with the police. People reporting drug use that day had lower odds of reporting not knowing where to find help. Men, gender-diverse people and people using drugs that day had greater odds of reporting concern about friends or relatives finding out. Discussion and Conclusions: Our data substantiate concerns regarding policing strategies and their impact on festivals. Initiatives to support conversations about drugs with friends and families may be best targeted to younger people and those from gender-diverse backgrounds
The genetic basis of endometriosis and comorbidity with other pain and inflammatory conditions
Endometriosis is a common condition associated with debilitating pelvic pain and infertility. A genome-wide association study meta-analysis, including 60,674 cases and 701,926 controls of European and East Asian descent, identified 42 genome-wide significant loci comprising 49 distinct association signals. Effect sizes were largest for stage 3/4 disease, driven by ovarian endometriosis. Identified signals explained up to 5.01% of disease variance and regulated expression or methylation of genes in endometrium and blood, many of which were associated with pain perception/maintenance (SRP14/BMF, GDAP1, MLLT10, BSN and NGF). We observed significant genetic correlations between endometriosis and 11 pain conditions, including migraine, back and multisite chronic pain (MCP), as well as inflammatory conditions, including asthma and osteoarthritis. Multitrait genetic analyses identified substantial sharing of variants associated with endometriosis and MCP/migraine. Targeted investigations of genetically regulated mechanisms shared between endometriosis and other pain conditions are needed to aid the development of new treatments and facilitate early symptomatic intervention
Identification of a BRCA2-Specific modifier locus at 6p24 related to breast cancer risk
Common genetic variants contribute to the observed variation in breast cancer risk for BRCA2 mutation carriers; those known to date have all been found through population-based genome-wide association studies (GWAS). To comprehensively identify breast cancer risk modifying loci for BRCA2 mutation carriers, we conducted a deep replication of an ongoing GWAS discovery study. Using the ranked P-values of the breast cancer associations with the imputed genotype of 1.4 M SNPs, 19,029 SNPs were selected and designed for inclusion on a custom Illumina array that included a total of 211,155 SNPs as part of a multi-consortial project. DNA samples from 3,881 breast cancer affected and 4,330 unaffected BRCA2 mutation carriers from 47 studies belonging to the Consortium of Investigators of Modifiers of BRCA1/2 were genotyped and available for analysis. We replicated previously reported breast cancer susceptibility alleles in these BRCA2 mutation carriers and for several regions (including FGFR2, MAP3K1, CDKN2A/B, and PTHLH) identified SNPs that have stronger evidence of association than those previously published. We also identified a novel susceptibility allele at 6p24 that was inversely associated with risk in BRCA2 mutation carriers (rs9348512; per allele HR = 0.85, 95% CI 0.80-0.90, P = 3.9×10−8). This SNP was not associated with breast cancer risk either in the general population or in BRCA1 mutation carriers. The locus lies within a region containing TFAP2A, which encodes a transcriptional activation protein that interacts with several tumor suppressor genes. This report identifies the first breast cancer risk locus specific to a BRCA2 mutation background. This comprehensive update of novel and previously reported breast cancer susceptibility loci contributes to the establishment of a panel of SNPs that modify breast cancer risk in BRCA2 mutation carriers. This panel may have clinical utility for women with BRCA2 mutations weighing options for medical prevention of breast cancer
The genetic basis of endometriosis and comorbidity with other pain and inflammatory conditions
Endometriosis is a common condition associated with debilitating pelvic pain and infertility. A genome-wide association study meta-analysis, including 60,674 cases and 701,926 controls of European and East Asian descent, identified 42 genome-wide significant loci comprising 49 distinct association signals. Effect sizes were largest for stage 3/4 disease, driven by ovarian endometriosis. Identified signals explained up to 5.01% of disease variance and regulated expression or methylation of genes in endometrium and blood, many of which were associated with pain perception/maintenance (SRP14/BMF, GDAP1, MLLT10, BSN and NGF). We observed significant genetic correlations between endometriosis and 11 pain conditions, including migraine, back and multisite chronic pain (MCP), as well as inflammatory conditions, including asthma and osteoarthritis. Multitrait genetic analyses identified substantial sharing of variants associated with endometriosis and MCP/migraine. Targeted investigations of genetically regulated mechanisms shared between endometriosis and other pain conditions are needed to aid the development of new treatments and facilitate early symptomatic intervention
Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk
BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat
An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers
Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe
Attention training for infants at familial risk of ADHD (INTERSTAARS): study protocol for a randomised controlled trial
Background: Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder that can
negatively impact on an individual’s quality of life. It is pathophysiologically complex and heterogeneous with
different neuropsychological processes being impaired in different individuals. Executive function deficits, including
those affecting attention, working memory and inhibitory control, are common. Cognitive training has been promoted
as a treatment option, based on the notion that by strengthening the neurocognitive networks underlying these
executive processes, ADHD symptoms will also be reduced. However, if implemented in childhood or later, when the
full disorder has become well-established, cognitive training has only limited value. INTERSTAARS is a trial designed to
test a novel approach to intervention, in which cognitive training is implemented early in development, before the
emergence of the disorder. The aim of INTERSTAARS is to train early executive skills, thereby increasing resilience and
reducing later ADHD symptoms and associated impairment.
Methods/design: Fifty 10–14-month-old infants at familial risk of ADHD will participate in INTERSTAARS. Infants
will be randomised to an intervention or a control group. The intervention aims to train early attention skills
by using novel eye-tracking technology and gaze-contingent training paradigms. Infants view animated games
on a screen and different events take place contingent on where on the screen the infant is looking. Infants
allocated to the intervention will receive nine weekly home-based attention training sessions. Control group
infants will also receive nine weekly home visits, but instead of viewing the training games during these visits
they will view non-gaze-contingent age-appropriate videos. At baseline and post treatment, infant attention
control will be assessed using a range of eye-tracking, observational, parent-report and neurophysiological
measures. The primary outcome will be a composite of eye-tracking tasks used to assess infant attention skills.
Follow-up data will be collected on emerging ADHD symptoms when the infants are 2 and 3 years old.
Discussion: This is the first randomised controlled trial to assess the potential efficacy of cognitive training as
a prevention measure for infants at familial risk of ADHD. If successful, INTERSTAARS could offer a promising
new approach for developing early interventions for ADHD.
Trial registration: International Standard Randomised Controlled Trial registry: ISRCTN37683928. Registered on
22 June 2015