scholarly journals A Genome-Wide Association Study To Understand the Effect of Fusarium verticillioides Infection on Seedlings of a Maize Diversity Panel

2020 ◽  
Vol 10 (5) ◽  
pp. 1685-1696
Author(s):  
Lorenzo Stagnati ◽  
Vahid Rahjoo ◽  
Luis F. Samayoa ◽  
James B. Holland ◽  
Virginia M. G. Borrelli ◽  
...  

Fusarium verticillioides, which causes ear, kernel and stem rots, has been reported as the most prevalent species on maize worldwide. Kernel infection by F. verticillioides results in reduced seed yield and quality as well as fumonisin contamination, and may affect seedling traits like germination rate, entire plant seedling length and weight. Maize resistance to Fusarium is a quantitative and complex trait controlled by numerous genes with small effects. In the present work, a Genome Wide Association Study (GWAS) of traits related to Fusarium seedling rot was carried out in 230 lines of a maize association population using 226,446 SNP markers. Phenotypes were scored on artificially infected kernels applying the rolled towel assay screening method and three traits related to disease response were measured in inoculated and not-inoculated seedlings: plant seedling length (PL), plant seedling weight (PW) and germination rate (GERM). Overall, GWAS resulted in 42 SNPs significantly associated with the examined traits. Two and eleven SNPs were associated with PL in inoculated and not-inoculated samples, respectively. Additionally, six and one SNPs were associated with PW and GERM traits in not-inoculated kernels, and further nine and thirteen SNPs were associated to the same traits in inoculated kernels. Five genes containing the significant SNPs or physically closed to them were proposed for Fusarium resistance, and 18 out of 25 genes containing or adjacent to significant SNPs identified by GWAS in the current research co-localized within QTL regions previously reported for resistance to Fusarium seed rot, Fusarium ear rot and fumonisin accumulation. Furthermore, linkage disequilibrium analysis revealed an additional gene not directly observed by GWAS analysis. These findings could aid to better understand the complex interaction between maize and F. verticillioides.

2018 ◽  
Author(s):  
Veena Devi Ganeshan ◽  
Stephen O. Opiyo ◽  
Samuel K. Mutiga ◽  
Felix Rotich ◽  
David M. Thuranira ◽  
...  

ABSTRACTThe fungal phytopathogen Magnaporthe oryzae causes blast disease in cereals such as rice and finger millet worldwide. In this study, we assessed genetic diversity of 160 isolates from nine sub-Saharan Africa (SSA) and other principal rice producing countries and conducted a genome-wide association study (GWAS) to identify the genomic regions associated with virulence of M. oryzae. GBS of isolates provided a large and high-quality 617K single nucleotide polymorphism (SNP) dataset. Disease ratings for each isolate was obtained by inoculating them onto differential lines and locally-adapted rice cultivars. Genome-wide association studies were conducted using the GBS dataset and sixteen disease rating datasets. Principal Component Analysis (PCA) was used an alternative to population structure analysis for studying population stratification from genotypic data. A significant association between disease phenotype and 528 SNPs was observed in six GWA analyses. Homology of sequences encompassing the significant SNPs was determined to predict gene identities and functions. Seventeen genes recurred in six GWA analyses, suggesting a strong association with virulence. Here, the putative genes/genomic regions associated with the significant SNPs are presented.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xue Ren ◽  
Guang-Li Yang ◽  
Wei-Feng Peng ◽  
Yong-Xin Zhao ◽  
Min Zhang ◽  
...  

Abstract Horns are a cranial appendage found exclusively in Bovidae, and play important roles in accessing resources and mates. In sheep (Ovies aries), horns vary from polled to six-horned, and human have been selecting polled animals in farming and breeding. Here, we conducted a genome-wide association study on 24 two-horned versus 22 four-horned phenotypes in a native Chinese breed of Sishui Fur sheep. Together with linkage disequilibrium (LD) analyses and haplotype-based association tests, we identified a genomic region comprising 132.0–133.1 Mb on chromosome 2 that contained the top 10 SNPs (including 4 significant SNPs) and 5 most significant haplotypes associated with the polycerate phenotype. In humans and mice, this genomic region contains the HOXD gene cluster and adjacent functional genes EVX2 and KIAA1715, which have a close association with the formation of limbs and genital buds. Our results provide new insights into the genetic basis underlying variable numbers of horns and represent a new resource for use in sheep genetics and breeding.


Heredity ◽  
2020 ◽  
Author(s):  
Yanhua Zhang ◽  
Yuzhe Wang ◽  
Yiyi Li ◽  
Junfeng Wu ◽  
Xinlei Wang ◽  
...  

Abstract Chicken growth traits are economically important, but the relevant genetic mechanisms have not yet been elucidated. Herein, we performed a genome-wide association study to identify the variants associated with growth traits. In total, 860 chickens from a Gushi-Anka F2 resource population were phenotyped for 68 growth and carcass traits, and 768 samples were genotyped based on the genotyping-by-sequencing (GBS) method. Finally, 734 chickens and 321,314 SNPs remained after quality control and removal of the sex chromosomes, and these data were used to carry out a GWAS analysis. A total of 470 significant single-nucleotide polymorphisms (SNPs) for 43 of the 68 traits were detected and mapped on chromosomes (Chr) 1–6, -9, -10, -16, -18, -23, and -27. Of these, the significant SNPs in Chr1, -4, and -27 were found to be associated with more than 10 traits. Multiple traits shared significant SNPs, indicating that the same mutation in the region might have a large effect on multiple growth or carcass traits. Haplotype analysis revealed that SNPs within the candidate region of Chr1 presented a mosaic pattern. The significant SNPs and pathway enrichment analysis revealed that the MLNR, MED4, CAB39L, LDB2, and IGF2BP1 genes could be putative candidate genes for growth and carcass traits. The findings of this study improve our understanding of the genetic mechanisms regulating chicken growth and carcass traits and provide a theoretical basis for chicken breeding programs.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhengfu Zhou ◽  
Huiyue Guan ◽  
Congcong Liu ◽  
Ziwei Zhang ◽  
Shenghui Geng ◽  
...  

Abstract Background Peroxidase (POD) activity plays an important role in flour-based product quality, which is mainly associated with browning and bleaching effects of flour. Here, we performed a genome-wide association study (GWAS) on POD activity using an association population consisted with 207 wheat world-wide collected varieties. Our study also provide basis for the genetic improvement of flour color-based quality in wheat. Results Twenty quantitative trait loci (QTLs) were detected associated with POD activity, explaining 5.59–12.67% of phenotypic variation. Superior alleles were positively correlated with POD activity. In addition, two SNPs were successfully developed to KASP (Kompetitive Allele-Specific PCR) markers. Two POD genes, TraesCS2B02G615700 and TraesCS2D02G583000, were aligned near the QTLs flanking genomic regions, but only TraesCS2D02G583000 displayed significant divergent expression levels (P < 0.001) between high and low POD activity varieties in the investigated association population. Therefore, it was deduced to be a candidate gene. The expression level of TraesCS2D02G583000 was assigned as a phenotype for expression GWAS (eGWAS) to screen regulatory elements. In total, 505 significant SNPs on 20 chromosomes (excluding 4D) were detected, and 9 of them located within 1 Mb interval of TraesCS2D02G583000. Conclusions To identify genetic loci affecting POD activity in wheat grain, we conducted GWAS on POD activity and the candidate gene TraesCS2D02G583000 expression. Finally, 20 QTLs were detected for POD activity, whereas two QTLs associated SNPs were converted to KASP markers that could be used for marker-assisted breeding. Both cis- and trans-acting elements were revealed by eGWAS of TraesCS2D02G583000 expression. The present study provides genetic loci for improving POD activity across wide genetic backgrounds and largely improved the selection efficiency for breeding in wheat.


2015 ◽  
Author(s):  
Longchao Zhang ◽  
Xin Liu ◽  
Jing Liang ◽  
Kebin Zhao ◽  
Hua Yan ◽  
...  

Porcine carcass that is approximately 800 mm long may be expected to have one additional vertebra. Therefore, the number of vertebrae in pigs is an economically important trait. To examine the genetic basis of this trait, we genotyped 593 F2 Large White × Minzhu pigs using the Porcine SNP60K BeadChip. A genome-wide association study identified 39 significant single-nucleotide polymorphisms (SNPs) on the chromosomes SSC1 and SSC7. An 8.82-Mb region that contained all 21 significant SNPs on SSC1 harbored the gene NR6A1, previously reported to influence the number of vertebrae in pigs. The remaining 18 significant SNPs on SSC7 were concentrated in a 4.56-Mb region, which was within the quantitative trait loci interval for number of vertebrae. A haplotype sharing analysis refined the locus to a segment of ~637 Kb. The most significant SNP, SIRI0001067, was contained in this refined region on SSC7 and located in one of the introns of TGFB3. As TGFB3 influences the development of vertebrae in mammalian embryos, the gene may be another strong candidate for the number of vertebrae in pigs.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0259939
Author(s):  
Yaiza Forcada ◽  
Mike Boursnell ◽  
Brian Catchpole ◽  
David B. Church

Diabetes mellitus (DM) is a common feline endocrinopathy, which is similar to human type 2 diabetes (T2DM) in terms of its pathophysiology. T2DM occurs due to peripheral insulin resistance and/or β-cell dysfunction. Several studies have identified genetic and environmental factors that contribute to susceptibility to human T2DM. In cats, environmental factors such as obesity and physical inactivity have been linked with DM, although to date, the only genetic association that has been demonstrated is with a polymorphism in the feline MC4R gene. The aim of this study was to perform a genome-wide association study (GWAS) to identify polymorphisms associated with feline DM. Illumina Infinium 63k iSelect DNA arrays were used to analyse genomic DNA samples from 200 diabetic domestic shorthair cats and 399 non-diabetic control cats. Data was analysed using PLINK whole genome data analysis toolset. A linear model analysis, EMMAX, was done to test for population structure and HAPLOVIEW was used to identify haplotype blocks surrounding the significant SNPs to assist with candidate gene nomination. A total of 47,497 SNPs were available for analysis. Four SNPs were identified with genome-wide significance: chrA2.4150731 (praw = 9.94 x10-8); chrUn17.115508 (praw = 6.51 x10-8); chrUn17.394136 (praw = 2.53 x10-8); chrUn17.314128 (praw = 2.53 x10-8) as being associated with DM. The first SNP is located within chromosome A2, less than 4kb upstream of the dipeptidyl-peptidase-9 (DPP9) gene, a peptidase involved in incretin inactivation. The remaining three SNPs are located within a haplotype block towards the end of chromosome A3; within this region, genes of interest include TMEM18 and ACP1, both previously associated with T2DM. This study indicates a polygenic component to susceptibility to DM in cats and has highlighted several loci and candidate genes worthy of further investigation.


Sign in / Sign up

Export Citation Format

Share Document