Identification of Anaplasma marginale, Babesia bovis and Babesia bigemina resistance alleles in Crioulo Lageano cattle using PCR-SBT and BoLA-DRB3 gene sequencing.

Introduction: The BoLA-DRB3 gene in cattle is associated with tolerance to several infectious diseases, such as neosporosis, dermatophilosis, leukosis, and mastitis. Methods: This study used PCR-SBT and BoLA-DRB3 gene sequencing to determine the association between the presence or absence of Anaplasma marginale, Babesia bovis, and Babesia bigemina infections in 208 Crioulo Lageano cattle and alleles present in the population. The chi-square test and odds ratio analysis were employed to establish the association. Results: Of the BoLA-DRB3 gene alleles present in the population, two alleles were significantly associated with resistance to A. marginale infections: BoLA-DRB3001:01 (p < 0.001; OR = 0.224), which had a frequency of 7.93%, and BoLA-DRB3024:06 (p = 0.007; OR < 0.00001), which had a frequency of 0.72%. Regarding B. bovis infection, the BoLA-DRB3*011:01 allele (p = 0.002; OR = 0.271) had a frequency of 6% in the population and was associated with resistance to the infection. None of the alleles was associated with resistance to infection by B. bigemina. Discussion: The Crioulo Lageano breed has alleles that may confer resistance against infection by A. marginale and B. bovis.

Prevalence and risk factors associated with Babesia bovis infection in Crioula Lageana cattle.

INTRODUCTION: Bovine babesiosis caused by the protozoan Babesia bovis is a worldwide disease and causes great economic damage to livestock. There are no studies on the epidemiology of this disease in native breeds such as Crioula Lageana cattle raised in the South of Brazil. METHODOLOGY: DNA samples from 311 animals were amplified by polymerase chain reaction (PCR) for the identification of the gene rap-1 (Rhoptry Associated Protein 1) from B. bovis. An epidemiological questionnaire was used to determine the risk factors associated with infection. RESULTS: The prevalence of B. bovis infection was 72% (224/311). Age and tick infestation affected infection. The factors associated with infection were the breeding objective (p = 0.042; CI = 0.746-0.995; OR = 0.861), contact of cattle with other animal species (p = 0.002; CI = 0.517-0.860; OR = 0.484), absence of tick control (p = < 0.001; CI = 0.074-0.480; OR = 0.188) and timing of tick treatment (p = 0.026; CI = 0.673-0.975; OR = 0.810), and these were considered to be factors that can protect against the disease. CONCLUSIONS: The Crioula Lageana cattle breed has near enzootic stability with regards to B. bovis infection.

Biochemical and histopathological responses in Nile tilapia exposed to a commercial insecticide mixture containing dinotefuran and lambda-cyhalothrin.

The indiscriminate use of pesticides has led to an increased risk of environmental contamination and pest resistance worldwide, favoring the development of less hazardous formulations. The commercial insecticide ZEUS® (Ihara, Brazil) combining dinotefuran and lambda-cyhalothrin was recently formulated in order to meet the environmental sustainability and food security. However, little is known about the potential toxic effects of ZEUS® to aquatic species. Thus, we report, for the first time, the biochemical and histological responses in tilapia (Oreochromis niloticus) following 96 h exposure to 0.01 mg/L, 0.05 mg/L and 0.1 mg/L ZEUS®. Different biochemical endpoints, including acetylcholinesterase (AChE), gamma-glutamyltransferase (GGT) and alkaline phosphatase (ALP), were assessed as potential biomarkers of insecticide effects. Glutathione S-transferase (GST) was evaluated as a marker of phase II biotransformation, and histopathological changes were measured to indicate gill alterations following ZEUS® exposure. After 96 h exposure, ZEUS® treatment increased GST activity in the liver of fish exposed to the highest concentration, while the intermediate dose increased both renal GGT and hepatic ALP activities. These findings reflect the importance of the liver and kidneys in the detoxification of ZEUS® and highlight the need to understand further toxicity effects. Likewise, the histopathological analysis of gills provided evidence that ZEUS® caused moderate damages. Despite biomarkers alterations reported for O. niloticus following ZEUS® exposure, by comparing our findings with data on toxicity of individual compounds, the commercial ZEUS® mixture seems to present similar or even lower adverse effects on freshwater fish.

Oxidative Stress and DNA Damage of Zebrafish Sperm at Different Stages of the Cryopreservation Process.

Although gamete cryopreservation has facilitated advancement of reproduction research by allowing the storage of cells over prolonged periods of time, during freezing-thawing cycles, cells inevitably suffer from cryoinjuries. Here, we evaluate oxidative stress and DNA damage of zebrafish sperm at different stages of the cryopreservation process. It was generally observed that the freezing and thawing of the samples led to an increase in the generation of reactive oxygen species and the activity of the catalase enzyme and a reduction in the generation of sulfhydryl groups and superoxide dismutase activity. The alkaline comet assay demonstrated that DNA damage increased after equilibration time, with an even greater increase after freezing and thawing. The comet assay modified with the enzyme formamidopyrimidine glycosylase, and Endonuclease III demonstrated greater DNA damage than the standard comet assay, demonstrating a high degree of oxidation of purines and pyrimidines at all stages of cryopreservation. Our results show that the freeze and thaw processes cause greater oxidative stress and DNA damage than cryoprotectant toxicity during exposure at the equilibrium stage.

Skim milk powder used as a non-permeable cryoprotectant reduces oxidative and DNA damage in cryopreserved zebrafish sperm.

Cryoprotectants play a vital role in the cryopreservation process, protecting biological samples from freezing damage. Here, we evaluate the effects of the combination and interaction of different extenders with permeable and non-permeable cryoprotectants, on the cryopreservation of Danio rerio sperm, analyzing the effects of cryopreservation through a broad approach to variables. Two extenders were used, Hank's balanced salt solution (HBSS) and Ginsburg's solution. Eight cryoprotective solutions (CS) were used: CS1 (HBSS + Me2SO 8%), CS2 (HBSS + Methanol 8%), CS3 (HBSS + Me2SO 8% + Skim milk powder 15%), CS4 (HBSS + Methanol 8% + Skim milk powder 15%), CS5 (Ginsburg + Me2SO 8%), CS6 (Ginsburg + Methanol 8%), CS7 (Ginsburg + Me2SO 8% + Skim milk powder 15%) and CS8 (Ginsburg + Methanol 8% + Skim milk powder 15%). The samples were cryopreserved in cryovials for 20 min on dry ice, stored in liquid nitrogen, thawed at 38 °C for 10 s, and analyzed. In addition to increasing viability, we show that powdered milk also allows for better preservation of the membrane and normal cell morphology, and protects the sperm cells from DNA damage and oxidative stress caused by cryopreservation.

High prevalence of Anaplasma marginale in the Crioula Lageana cattle.

INTRODUCTION: Bovine anaplasmosis is caused by the bacterium Anaplasma marginale; its transmission occurs through vectors such as ticks. Crioula Lageana is a native cattle breed from the South of Brazil used for beef production, with excellent meat quality. There are no studies of the epidemiology of this disease in Crioula Lageana even though tick damage is known to be frequent. METHODOLOGY: Blood samples were collected from 311 Crioula Lageana cattle and subjected to DNA extraction and polymerase chain reaction (PCR) using specific primers for the Major Surface Protein 5 (msp5) gene for the detection of the bovine anaplasmosis agent. The animals were classified according to the gender, the category and the presence or absence of ticks at the time of collection. The animal owners completed an epidemiological questionnaire to determine factors that might be associated with anaplasma infection. RESULTS: The prevalence of A. marginale was 79.9%. The following factors were found to be protective against infection: I) the breeding objectives (whether animals were destined for beef production and trade or solely for beef production), II) tick control rate; and III) pregnant and lactating cows and calves as the categories least affected by the hemoparasite. The main risk factor for hemoparasite acquisition was the use of organophosphates and avermectins as acaricides. CONCLUSIONS: Crioula Lageana cattle are in a situation of enzootic stability, with a high prevalence of A. marginale infection. The factors associated with the infection were: I) breeding objectives, II) tick control rate, III) the acaricides used, and IV) the most tick-parasitized categories of cattle.

Prevalence of Anaplasma marginale, Babesia bovis, and Babesia bigemina in cattle in the Campos de Lages region, Santa Catarina state, Brazil, estimated by multiplex-PCR.

This study aimed to determine the prevalence of three common hemoparasites (Anaplasma marginale, Babesia bovis and Babesia bigemina) in cattle from 16 counties in the Campos de Lages region, Santa Catarina state, Brazil, and the factors affecting disease occurrence. The study population consisted of 257 clinically healthy animals from 21 rural farms. Bovine blood samples were collected by jugular venipuncture. DNA was extracted from whole blood by the phenol/ chloroform method. Genomic DNA extracted from blood samples was subjected to Multiplex PCR for screening of B. bovis, B. bigemina, and A. marginale using specific primers. Prevalences of A. marginale, B. bigemina, and B. bovis were 27%, 16%, and 29%, respectively. Mixed infection was observed in 17.5% of samples. The most frequent was Babesia bovis and Babesia bigemina in 6.62% of samples. A. marginale infection rates were statistically correlated with age groups of cattle. The infections detected in the study population were considered to be subclinical, based on the presence pathogen DNA and absence of clinical symptoms. Seasonality of the pathogens resulted in various degrees of infection, related to the age of the animals and the season. The Campos de Lages region is characterized by enzootic instability for these pathogens because of its climatic and geographic features.

Metal bioaccumulation, oxidative stress and antioxidant responses in oysters Crassostrea gasar transplanted to an estuary in southern Brazil.

The present study assessed the spatial and temporal variations on metal bioaccumulation and biochemical biomarker responses in oysters Crassostrea gasar transplanted to two different sites (S1 and S2) at the Laguna Estuarine System (LES), southern Brazil, over a 45-days period. A multi-biomarker approach was used, including the evaluation of lipid peroxidation (MDA) levels, and antioxidant defense enzymes (CAT, GPx, GR and G6PDH) and phase II biotransformation enzyme (GST) in the gills and digestive gland of oysters in combination with the quantification of Al, Cd, Cu, Pb, Fe, Ni and Zn in both tissues. The exposed oysters bioaccumulated metals, especially Al, Cd and Zn in gills and digestive gland, with most prominent biomarker responses in the gills. Results showed that GPx, GR and G6PDH enzymes offered an increased and coordinated response possibly against metal (Zn, Ni, Cd and Cu) contamination in gills. GST was inversely correlated to Cd levels, being its activity significantly lowered over the 45-d exposure periods at S2. On contrary, in digestive gland GST was slightly positively correlated to Cd, revealing a compensatory mechanism between tissues to protect oysters' cells against oxidative damages, since MDA levels also decreased. CAT also appeared to be involved in the cellular protection against oxidative stress, being increased in gills. However, CAT was negatively correlated to Al levels, which might suggest a possible inhibitory effect of this metal in the gills of C. gasar. Differences between tissues were evident by the Integrative Biomarker Responses version 2 (IBRv2) indexes, which showed different pattern between tissues when studying the sites and exposure periods separately. This study provided evidence for the effectiveness of using a multi-biomarker approach in oyster C. gasar to monitor estuarine metal pollution.

Analysis of Genes Involved in Body Weight Regulation by Targeted Re-Sequencing.

INTRODUCTION: Genes involved in body weight regulation that were previously investigated in genome-wide association studies (GWAS) and in animal models were target-enriched followed by massive parallel next generation sequencing. METHODS: We enriched and re-sequenced continuous genomic regions comprising FTO, MC4R, TMEM18, SDCCAG8, TKNS, MSRA and TBC1D1 in a screening sample of 196 extremely obese children and adolescents with age and sex specific body mass index (BMI) ≥ 99th percentile and 176 lean adults (BMI ≤ 15th percentile). 22 variants were confirmed by Sanger sequencing. Genotyping was performed in up to 705 independent obesity trios (extremely obese child and both parents), 243 extremely obese cases and 261 lean adults. RESULTS AND CONCLUSION: We detected 20 different non-synonymous variants, one frame shift and one nonsense mutation in the 7 continuous genomic regions in study groups of different weight extremes. For SNP Arg695Cys (rs58983546) in TBC1D1 we detected nominal association with obesity (pTDT = 0.03 in 705 trios). Eleven of the variants were rare, thus were only detected heterozygously in up to ten individual(s) of the complete screening sample of 372 individuals. Two of them (in FTO and MSRA) were found in lean individuals, nine in extremely obese. In silico analyses of the 11 variants did not reveal functional implications for the mutations. Concordant with our hypothesis we detected a rare variant that potentially leads to loss of FTO function in a lean individual. For TBC1D1, in contrary to our hypothesis, the loss of function variant (Arg443Stop) was found in an obese individual. Functional in vitro studies are warranted.

Relationship between MTNR1B (melatonin receptor 1B gene) polymorphism rs10830963 and glucose levels in overweight children and adolescents.

AIMS: The G-allele of the single nucleotide polymorphism (SNP) rs10830963 in MTNR1B (melatonin receptor 1B gene) is associated with type 2 diabetes mellitus and glucose levels in adults. The aim of this study was to analyze whether there is an allele-dosage effect on glucose metabolism in overweight children and to explore if changes in glucose metabolism in a lifestyle intervention do also depend on genotype. METHODS: We genotyped rs10830963 in 1118 overweight children and adolescents [mean age 10.7 yr, mean body mass index (BMI) 27.8 kg/m2]; 340 of these individuals completed a 1-yr lifestyle intervention (mean age 10.7 yr, mean BMI 27.9 kg/m2). The degree of overweight [BMI-SDS (standard deviation score)], fasting insulin, glucose, homeostasis model assessment for insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were measured before and after intervention. RESULTS: We showed a significant relationship between rs10830963 and basal glucose levels [ß:1.101, 95% confidence interval (CI) 0.316-1.886 mg/dL per risk allele; p = 0.006] by linear regression adjusted for age, age(2), and sex. There was no effect of the allele on insulin or indices of insulin resistance or sensitivity. After the 1-yr lifestyle intervention, we observed a significant reduction of BMI-SDS as well as an improvement of HOMA-IR and QUICKI, but no evidence for an association between rs10830963 genotype and changes of glucose levels. CONCLUSIONS: The G-allele of rs10830693 in the MTNR1B gene was significantly related to glucose levels, while an impact of this genetic variant on the changes in glucose metabolism in children participating in a lifestyle intervention was not observable.

Common variants near MC4R: exploring gender effects in overweight and obese children and adolescents participating in a lifestyle intervention.

OBJECTIVE: Association with obesity and increased insulin levels have been reported for two variants (rs17782313 and rs12970134) located downstream of the melanocortin-4 receptor gene (MC4R). METHODS: We investigated whether these variants have sex-specific effects on overweight, obesity and 14 related phenotypes in 889 overweight and obese children and adolescents. We also explored the impact of the variants on weight change in 367 of the 889 cases who participated in an intervention program. Prior to these analyses we showed that both variants were associated with overweight/obesity in the analyzed 889 cases versus 442 normal-weight and lean controls (case-control study). RESULTS: In explorative analyses we observed higher diastolic blood pressure levels in males (rs17782313: ß = 2.52 mm Hg per risk allele; p = 0.003) but reduced blood pressure level in females for the same risk allele (ß = -1.72 mm Hg; p = 0.039). We also detected a greater BMI standard deviation score (BMI-SDS) reduction in females with the risk allele at rs17782313 (ß = 0.086 per risk allele; p = 0.021). Additionally, we observed evidence for an association of the same risk allele with insulin levels (ß = 0.029 log (µU/ml); p = 0.044) with no sex-specific effect. For the remaining 11 phenotypes, we observed no evidence for a (sex-specific) association. CONCLUSIONS: In sum, our data support the associations of variants rs17782313 and rs12970134 near MC4R with early onset obesity and increased insulin levels. Exploratory evidence for sex-specific effects of the risk alleles were observed for diastolic blood pressure and BMI-SDS reduction.

Novel common copy number variation for early onset extreme obesity on chromosome 11q11 identified by a genome-wide analysis.

Heritability of obesity is substantial and recent meta-analyses of genome-wide association studies (GWASs) have been successful in detecting several robustly associated genomic regions for obesity using single-nucleotide polymorphisms (SNPs). However, taken together, the SNPs explain only a small proportion of the overall heritability. Copy number variations (CNVs) might contribute to the 'missing heritability'. We searched genome-wide for association between common CNVs and early-onset extreme obesity. Four hundred and twenty-four case-parents obesity trios and an independent sample of 453 extremely obese children and adolescents and 435 normal-weight and lean adult controls were genotyped by the Affymetrix Genome-Wide Human SNP Array 6.0. We detected 20 common copy number variable regions (CNVRs) which were associated with obesity. The most promising CNVRs were followed-up in an independent sample of 365 obesity trios, confirming the association for two candidate CNVRs. We identified a common CNVR exclusively covering the three olfactory receptor genes OR4P4, OR4S2 and OR4C6 to be associated with obesity (combined P-value = 0.015 in a total of 789 families; odds ratio for the obesity effect allele = 1.19; 95% confidence interval = 1.016-1.394). We also replicated two common deletions (near NEGR1 and at chromosome 10q11.22) that have previously been reported to be associated with body weight. Additionally, we support a rare CNV on chromosome 16 that has recently been reported by two independent groups. However, rare CNVs had not been the focus of our study. We conclude that common CNVs are unlikely to contribute substantially to the genetic basis of early-onset extreme obesity.

Investigation of a genome wide association signal for obesity: synthetic association and haplotype analyses at the melanocortin 4 receptor gene locus.

BACKGROUND: Independent genome-wide association studies (GWAS) showed an obesogenic effect of two single nucleotide polymorphisms (SNP; rs12970134 and rs17782313) more than 150 kb downstream of the melanocortin 4 receptor gene (MC4R). It is unclear if the SNPs directly influence MC4R function or expression, or if the SNPs are on a haplotype that predisposes to obesity or includes functionally relevant genetic variation (synthetic association). As both exist, functionally relevant mutations and polymorphisms in the MC4R coding region and a robust association downstream of the gene, MC4R is an ideal model to explore synthetic association. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed a genomic region (364.9 kb) encompassing the MC4R in GWAS data of 424 obesity trios (extremely obese child/adolescent and both parents). SNP rs12970134 showed the lowest p-value (p = 0.004; relative risk for the obesity effect allele: 1.37); conditional analyses on this SNP revealed that 7 of 78 analyzed SNPs provided independent signals (p≤0.05). These 8 SNPs were used to derive two-marker haplotypes. The three best (according to p-value) haplotype combinations were chosen for confirmation in 363 independent obesity trios. The confirmed obesity effect haplotype includes SNPs 3' and 5' of the MC4R. Including MC4R coding variants in a joint model had almost no impact on the effect size estimators expected under synthetic association. CONCLUSIONS/SIGNIFICANCE: A haplotype reaching from a region 5' of the MC4R to a region at least 150 kb from the 3' end of the gene showed a stronger association to obesity than single SNPs. Synthetic association analyses revealed that MC4R coding variants had almost no impact on the association signal. Carriers of the haplotype should be enriched for relevant mutations outside the MC4R coding region and could thus be used for re-sequencing approaches. Our data also underscore the problems underlying the identification of relevant mutations depicted by GWAS derived SNPs.

Two new Loci for body-weight regulation identified in a joint analysis of genome-wide association studies for early-onset extreme obesity in French and german study groups.

Meta-analyses of population-based genome-wide association studies (GWAS) in adults have recently led to the detection of new genetic loci for obesity. Here we aimed to discover additional obesity loci in extremely obese children and adolescents. We also investigated if these results generalize by estimating the effects of these obesity loci in adults and in population-based samples including both children and adults. We jointly analysed two GWAS of 2,258 individuals and followed-up the best, according to lowest p-values, 44 single nucleotide polymorphisms (SNP) from 21 genomic regions in 3,141 individuals. After this DISCOVERY step, we explored if the findings derived from the extremely obese children and adolescents (10 SNPs from 5 genomic regions) generalized to (i) the population level and (ii) to adults by genotyping another 31,182 individuals (GENERALIZATION step). Apart from previously identified FTO, MC4R, and TMEM18, we detected two new loci for obesity: one in SDCCAG8 (serologically defined colon cancer antigen 8 gene; p = 1.85x10(-8) in the DISCOVERY step) and one between TNKS (tankyrase, TRF1-interacting ankyrin-related ADP-ribose polymerase gene) and MSRA (methionine sulfoxide reductase A gene; p = 4.84x10(-7)), the latter finding being limited to children and adolescents as demonstrated in the GENERALIZATION step. The odds ratios for early-onset obesity were estimated at approximately 1.10 per risk allele for both loci. Interestingly, the TNKS/MSRA locus has recently been found to be associated with adult waist circumference. In summary, we have completed a meta-analysis of two GWAS which both focus on extremely obese children and adolescents and replicated our findings in a large followed-up data set. We observed that genetic variants in or near FTO, MC4R, TMEM18, SDCCAG8, and TNKS/MSRA were robustly associated with early-onset obesity. We conclude that the currently known major common variants related to obesity overlap to a substantial degree between children and adults.

From monogenic to polygenic obesity: recent advances.

The heritability of obesity and body weight in general is high. A small number of confirmed monogenic forms of obesity-the respective mutations are sufficient by themselves to cause the condition in food abundant societies-have been identified by molecular genetic studies. The elucidation of these genes, mostly based on animal and family studies, has led to the identification of important pathways to the disorder and thus to a deeper understanding of the regulation of body weight. The identification of inborn deficiency of the mostly adipocyte-derived satiety hormone leptin in extremely obese children from consanguineous families paved the way to the first pharmacological therapy for obesity based on a molecular genetic finding. The genetic predisposition to obesity for most individuals, however, has a polygenic basis. A polygenic variant by itself has a small effect on the phenotype; only in combination with other predisposing variants does a sizeable phenotypic effect arise. Common variants in the first intron of the 'fat mass and obesity associated' gene (FTO) result in an elevated body mass index (BMI) equivalent to approximately +0.4 kg/m(2) per risk allele. The FTO variants were originally detected in a genome wide association study (GWAS) pertaining to type 2 diabetes mellitus. Large meta-analyses of GWAS have subsequently identified additional polygenic variants. Up to December 2009, polygenic variants have been confirmed in a total of 17 independent genomic regions. Further study of genetic effects on human body weight regulation should detect variants that will explain a larger proportion of the heritability. The development of new strategies for diagnosis, treatment and prevention of obesity can be anticipated.

Large effects on body mass index and insulin resistance of fat mass and obesity associated gene (FTO) variants in patients with polycystic ovary syndrome (PCOS).

BACKGROUND: The polycystic ovary syndrome (PCOS), a common endocrine disorder in women of child-bearing age, mainly characterised by chronic anovulation and hyperandrogenism, is often associated with insulin resistance (IR) and obesity. Its etiology and the role of IR and obesity in PCOS are not fully understood. We examined the influence of validated genetic variants conferring susceptibility to obesity and/or type 2 diabetes mellitus (T2DM) on metabolic and PCOS-specific traits in patients with PCOS. METHODS: We conducted an association study in 386 patients with PCOS (defined by the Rotterdam-criteria) using single nucleotide polymorphisms (SNPs) in or in proximity to the fat mass and obesity associated gene (FTO), insulin-induced gene-2 (INSIG2), transcription factor 7-like 2 gene (TCF7L2) and melanocortin 4 receptor gene (MC4R). To compare the effect of FTO obesity risk alleles on BMI in patients with PCOS to unselected females of the same age range we genotyped 1,971 females from the population-based KORA-S4 study (Kooperative Gesundheitsforschung im Raum Augsburg, Survey 4). RESULTS: The FTO risk allele was associated with IR traits and measures of increased body weight. In addition, the TCF7L2 SNP was associated with body weight traits. For the SNPs in the vicinity of INSIG2 and MC4R and for the other examined phenotypes there was no evidence for an association. In PCOS the observed per risk allele effect of FTO intron 1 SNP rs9939609 on BMI was +1.56 kg/m2, whereas it was +0.46 kg/m2 in females of the same age range from the general population as shown previously. CONCLUSION: The stronger effect on body weight of the FTO SNP in PCOS might well have implications for the etiology of the disease.

Mutation screen and association studies for the fatty acid amide hydrolase (FAAH) gene and early onset and adult obesity.

BACKGROUND: The orexigenic effects of cannabinoids are limited by activation of the endocannabinoid degrading enzyme fatty acid amide hydrolase (FAAH). The aim of this study was to analyse whether FAAH alleles are associated with early and late onset obesity. METHODS: We initially assessed association of five single nucleotide polymorphisms (SNPs) in FAAH with early onset extreme obesity in up to 521 German obese children and both parents. SNPs with nominal p-values 0.05). CONCLUSIONS: As we observed some evidence for an association of the FAAH variants rs2295632 rs324420 with early onset but not adult obesity, we conclude that the FAAH variants analyzed here at least do not seem to play a major role in the etiology of obesity within our samples.

Gastric inhibitory polypeptide receptor: association analyses for obesity of several polymorphisms in large study groups.

BACKGROUND: Gastric inhibitory polypeptide (GIP) is postulated to be involved in type 2 diabetes mellitus and obesity. It exerts its function through its receptor, GIPR. We genotyped three GIPR SNPs (rs8111428, rs2302382 and rs1800437) in German families with at least one obese index patient, two case-control studies and two cross-sectional population-based studies. METHODS: Genotyping was performed by MALDI-TOF, ARMS-PCR and RFLP. The family-study: 761 German families with at least one extremely obese child or adolescent (n = 1,041) and both parents (n = 1,522). Case-control study: (a) German obese children (n = 333) and (b) obese adults (n = 987) in comparison to 588 adult lean controls. The two cross-sectional population-based studies: KORA (n = 8,269) and SHIP (n = 4,310). RESULTS: We detected over-transmission of the A-allele of rs2302382 in the German families (pTDT-Test = 0.0089). In the combined case-control sample, we estimated an odd ratio of 1.54 (95%CI 1.09;2.19, pCA-Test = 0.014) for homozygotes of the rs2302382 A-allele compared to individuals with no A-allele. A similar trend was found in KORA where the rs2302382 A-allele led to an increase of 0.12 BMI units (p = 0.136). In SHIP, however, the A-allele of rs2302382 was estimated to contribute an average decrease of 0.27 BMI units (p-value = 0.031). CONCLUSION: Our data suggest a potential relevance of GIPR variants for obesity. However, additional studies are warranted in light of the conflicting results obtained in one of the two population-based studies.

Non-replication of an association of CTNNBL1 polymorphisms and obesity in a population of Central European ancestry.

BACKGROUND: A recent genome-wide association (GWA) study of U.S. Caucasians suggested that eight single nucleotide polymorphisms (SNPs) in CTNNBL1 are associated with obesity and increased fat mass. We analysed the respective SNPs in data from our previously published GWA for early onset obesity (case-control design), in GWA data from a population-based cohort of adults, and in an independent family-based obesity study. We investigated whether variants in CTNNBL1 (including rs6013029) and in three other genes (SH3PXD2B, SLIT3 and FLJ42133,) were associated with obesity. METHODS: The GWA studies were carried out using Affymetrix(R) SNP Chips with approximately 500,000 markers each. In the families, SNP rs6013029 was genotyped using the TaqMan(R) allelic discrimination assay. The German case-control GWA included 487 extremely obese children and adolescents and 442 healthy lean individuals. The adult GWA included 1,644 individuals from a German population-based study (KORA). The 775 independent German families consisted of extremely obese children and adolescents and their parents. RESULTS: We found no evidence for an association of the reported variants in CTNNBL1 with early onset obesity or increased BMI. Further, in our family-based study we found no evidence for over-transmission of the rs6013029 risk-allele T to obese children. Additionally, we found no evidence for an association of SH3PXD2B, SLIT3 and FLJ42133 variants in our two GWA samples. CONCLUSION: We detected no confirmation of the recent association of variants in CTNNBL1 with obesity in a population of Central European ancestry.