116 research outputs found
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Selecting for food-feed traits in desi and kabuli genotypes of chickpea (Cicer arietinum)
The study explored the genetic and environmental variability in chickpea for food-feed traits. Seventy nine genotypes of 17 early-maturing desi genotypes, 19 early-maturing kabuli genotypes and 43 late-maturing kabuli genotypes were evaluated for food-feed traits in 7 trials laid out in a randomized complete block design in 3 locations in Ethiopia. All trials showed wide genotypic ranges in various traits related to grain yield, straw yield and straw quality. Analysis of variance for individual trials showed significant (P<0.05) effects of genotype, location and their interaction on grain and straw yields, CP, IVOMD and NDF in all populations. Correlation analysis exhibited either positive or insignificant correlations with straw yield in all trials. The correlation between IVOMD and grain yield was insignificant in all trials. Grain yield correlated significantly (P<0.001) and positively to NDF in early maturing kabuli, however, the correlation was moderate (r= 0.396). Grain yield correlated either weakly or insignificantly to CP and Ca in the trials. The correlation between P and grain yield was ignored as the straw content of P was very small in all genotypes (<1.78 g/kg). Weak or absence of correlations between grain yields with straw traits would enable chickpea breeders to manipulate grain yield and straw traits independently. This presents an opportunity to identify parental genotypes for improving grain yield and straw traits for individual locations
Selecting for food-feed traits in early and late maturing lentil genotypes(Lens culinaris)
To explore genetic and environmental variability of food-feed traits in lentil genotypes, straws of 78elite genotypes and 4 checks of early and late maturing lentil types were evaluated for their nutritive value and potential trade-offs of the nutritive parameters with straw yield and grain yield. Further, effects of genotypic and environmental sources on variation in the nutritive value were also determined. Straw nutritive traits were analyzed by a combination of conventional laboratory techniques and Near Infrared Reflectance Spectroscopy. Results from eight trials carried out across 3 different sites in Ethiopia showed highly significant genotypic variation (P<0.05) in grain yield, straw yields and straw nutritive traits. This confirmed the existence of exploitable genetic variation in these traits. Similarly, the relationship between grain yield and straw yield was positive. The correlation between grain yield and nutritive parameters of straw was insignificant or negative. The correlation between maturity types and straw traits was either neutral or negative. Genotype by environment interactions were significant (P<0.05) for straw yield and nutritive traits indicating that variation in the traits is dependent of environment. It is possible to develop genotypes with a combination of food-feed traits from early and late maturing lentil types to address the high demand for grain and livestock fodder in various agro ecological zones in mixed crop-livestock farming systems using appropriate breeding approaches
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Optimizing near infrared reflectance spectroscopy to predict nutritional quality of chickpea straw for livestock feeding
Multidimensional improvement programs of chickpea require screening of a large number of genotypes for straw nutritive value. The ability of near infrared reflectance spectroscopy (NIRS) to determine the nutritive value of chickpea straw was identified in the current study. A total of 480 samples of chickpea straw representing a nation-wide range of environments and genotypic diversity (40 genotypes) were scanned at a spectral range of 1108 to 2492 nm. The samples were reduced to 190 representative samples based on the spectral data then divided into a calibration set (160 samples) and a cross-validation set (30 samples). All 190 samples were analysed for dry matter, ash, crude protein, neutral detergent fibre, acid detergent fibre, acid detergent lignin, Zn, Mn, Ca, Mg, Fe, P, and in vitro gas production metabolizable energy using conventional methods. Multiple regression analysis was used to build the prediction equations. The prediction equation generated by the study accurately predicted the nutritive value of chickpea straw (R2 of cross validation > 0.68; standard error of prediction < 1%). Breeding programs targeting improving food-feed traits of chickpea could use NIRS as a fast, cheap, and reliable tool to screen genotypes for straw nutritional quality
Identification of Type 1 Diabetes-Associated DNA Methylation Variable Positions That Precede Disease Diagnosis
Monozygotic (MZ) twin pair discordance for childhood-onset Type 1 Diabetes (T1D) is similar to 50%, implicating roles for genetic and non-genetic factors in the aetiology of this complex autoimmune disease. Although significant progress has been made in elucidating the genetics of T1D in recent years, the non-genetic component has remained poorly defined. We hypothesized that epigenetic variation could underlie some of the non-genetic component of T1D aetiology and, thus, performed an epigenome-wide association study (EWAS) for this disease. We generated genome-wide DNA methylation profiles of purified CD14(+) monocytes (an immune effector cell type relevant to T1D pathogenesis) from 15 T1D-discordant MZ twin pairs. This identified 132 different CpG sites at which the direction of the intra-MZ pair DNA methylation difference significantly correlated with the diabetic state, i.e. T1D-associated methylation variable positions (T1D-MVPs). We confirmed these T1D-MVPs display statistically significant intra-MZ pair DNA methylation differences in the expected direction in an independent set of T1D-discordant MZ pairs (P = 0.035). Then, to establish the temporal origins of the T1D-MVPs, we generated two further genome-wide datasets and established that, when compared with controls, T1D-MVPs are enriched in singletons both before (P = 0.001) and at (P = 0.015) disease diagnosis, and also in singletons positive for diabetes-associated autoantibodies but disease-free even after 12 years follow-up (P = 0.0023). Combined, these results suggest that T1D-MVPs arise very early in the etiological process that leads to overt T1D. Our EWAS of T1D represents an important contribution toward understanding the etiological role of epigenetic variation in type 1 diabetes, and it is also the first systematic analysis of the temporal origins of disease-associated epigenetic variation for any human complex disease
Increased DNA methylation variability in type 1 diabetes across three immune effector cell types
The incidence of type 1 diabetes (T1D) has substantially increased over the past decade, suggesting a role for non-genetic factors such as epigenetic mechanisms in disease development. Here we present an epigenome-wide association study across 406,365 CpGs in 52 monozygotic twin pairs discordant for T1D in three immune effector cell types. We observe a substantial enrichment of differentially variable CpG positions (DVPs) in T1D twins when compared with their healthy co-twins and when compared with healthy, unrelated individuals. These T1D-associated DVPs are found to be temporally stable and enriched at gene regulatory elements. Integration with cell type-specific gene regulatory circuits highlight pathways involved in immune cell metabolism and the cell cycle, including mTOR signalling. Evidence from cord blood of newborns who progress to overt T1D suggests that the DVPs likely emerge after birth. Our findings, based on 772 methylomes, implicate epigenetic changes that could contribute to disease pathogenesis in T1D.This work was funded by the EU-FP7 project BLUEPRINT (282510) and the Wellcome Trust (99148). We thank all twins for taking part in this study; Kerra Pearce and Mark Kristiansen (UCL Genomics) for processing the Illumina Infinium HumanMethylation450 BeadChips; Rasmus Bennet for technical assistance; and Laura Phipps for proofreading the manuscript. The BMBF Pediatric Diabetes Biobank recruits patients from the National Diabetes Patient Documentation System (DPV), and is financed by the German Ministry of Education and Research within the German Competence Net Diabetes Mellitus (01GI1106 and 01GI1109B). It was integrated into the German Center for Diabetes Research in January 2015. We thank the Swedish Research Council and SUS Funds for support. We gratefully acknowledge the participation of all NIHR Cambridge BioResource volunteers, and thank the Cambridge BioResource staff for their help with volunteer recruitment. We thank members of the Cambridge BioResource SAB and Management Committee for their support of our study and the NIHR Cambridge Biomedical Research Centre for funding. The Cardiovascular Epidemiology Unit is supported by the UK Medical Research Council (G0800270), BHF (SP/09/002), and NIHR Cambridge Biomedical Research Centre. Research in the Ouwehand laboratory is supported by the NIHR, BHF (PG-0310-1002 and RG/09/12/28096) and NHS Blood and Transplant. K.D. is funded as a HSST trainee by NHS Health Education England. M.F. is supported by the BHF Cambridge Centre of Excellence (RE/13/6/30180). A.D., E.L., L.C. and P.F. receive additional support from the European Molecular Biology Laboratory. A.K.S. is supported by an ADA Career Development Award (1-14-CD-17). B.O.B. and R.D.L. acknowledge support from the Deutsche Forschungsgemeinschaft (DFG) and European Federation for the Study of Diabetes, respectively
Extracting Statistically Significant Behaviour from Fish Tracking Data With and Without Large Dataset Cleaning
Extracting a statistically significant result from video of natural phenomenon can be difficult for two reasons: (i) there can be considerable natural variation in the observed behaviour and (ii) computer vision algorithms applied to natural phenomena may not perform correctly on a significant number of samples. This study presents one approach to clean a large noisy visual tracking dataset to allow extracting statistically sound results from the image data. In particular, analyses of 3.6 million underwater trajectories of a fish with the water temperature at the time of acquisition are presented. Although there are many false detections and incorrect trajectory assignments, by a combination of data binning and robust estimation methods, reliable evidence for an increase in fish speed as water temperature increases are demonstrated. Then, a method for data cleaning which removes outliers arising from false detections and incorrect trajectory assignments using a deep learning‐based clustering algorithm is proposed. The corresponding results show a rise in fish speed as temperature goes up. Several statistical tests applied to both cleaned and not‐cleaned data confirm that both results are statistically significant and show an increasing trend. However, the latter approach also generates a cleaner dataset suitable for other analysis
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