scholarly journals Apple Ripening Is Controlled by a NAC Transcription Factor

2021 ◽  
Vol 12 ◽  
Author(s):  
Zoë Migicovsky ◽  
Trevor H. Yeats ◽  
Sophie Watts ◽  
Jun Song ◽  
Charles F. Forney ◽  
...  

Softening is a hallmark of ripening in fleshy fruits, and has both desirable and undesirable implications for texture and postharvest stability. Accordingly, the timing and extent of pre-harvest ripening and associated textural changes following harvest are key targets for improving fruit quality through breeding. Previously, we identified a large effect locus associated with harvest date and firmness in apple (Malus domestica) using genome-wide association studies (GWAS). Here, we present additional evidence that polymorphisms in or around a transcription factor gene, NAC18.1, may cause variation in these traits. First, we confirmed our previous findings with new phenotype and genotype data from ∼800 apple accessions. In this population, we compared a genetic marker within NAC18.1 to markers targeting three other firmness-related genes currently used by breeders (ACS1, ACO1, and PG1), and found that the NAC18.1 marker was the strongest predictor of both firmness at harvest and firmness after 3 months of cold storage. By sequencing NAC18.1 across 18 accessions, we revealed two predominant haplotypes containing the single nucleotide polymorphism (SNP) previously identified using GWAS, as well as dozens of additional SNPs and indels in both the coding and promoter sequences. NAC18.1 encodes a protein that is orthogolous to the NON-RIPENING (NOR) transcription factor, a regulator of ripening in tomato (Solanum lycopersicum). We introduced both NAC18.1 transgene haplotypes into the tomato nor mutant and showed that both haplotypes complement the nor ripening deficiency. Taken together, these results indicate that polymorphisms in NAC18.1 may underlie substantial variation in apple firmness through modulation of a conserved ripening program.

2019 ◽  
Author(s):  
Trevor H. Yeats ◽  
Zoë Migicovsky ◽  
Sophie Watts ◽  
Jun Song ◽  
Charles F. Forney ◽  
...  

AbstractSoftening is a hallmark of ripening in fleshy fruits, and has both desirable and undesirable implications for texture and postharvest stability. Accordingly, the timing and extent of ripening and associated textural changes are key targets for improving fruit quality through breeding. Previously, we identified a large effect locus associated with harvest date and firmness in apple (Malus domestica) using genome-wide association studies (GWAS). Here, we present additional evidence that polymorphisms in or around a transcription factor gene, NAC18.1, cause variation in these traits. First, we confirmed our previous findings with new phenotype and genotype data from ~800 apple accessions. In this population, we compared NAC18.1 to three other ripening-related markers currently used by breeders (ACS1, ACO1, and PG1), and found that the effect of the NAC18.1 genotype on both traits greatly exceeded that observed for the other markers. By sequencing NAC18.1 across 18 accessions, we revealed two predominant haplotypes containing the SNP previously identified using GWAS, as well as dozens of additional SNPs and indels in both the coding and promoter sequences. NAC18.1 encodes a protein with high similarity to the NON-RIPENING (NOR) transcription factor, an early regulator of ripening in tomato (Solanum lycopersicum). To test whether these genes are functionally orthologous, we introduced NAC18.1 transgenes into the tomato nor mutant and showed that both haplotypes complement the nor ripening deficiency. Taken together, these results indicate that polymorphisms in NAC18.1 underlie substantial variation in apple firmness and harvest time through modulation of a conserved ripening program.HighlightNAC18.1 is a member of a family of conserved transcriptional regulators of ripening that underlies variation in fruit firmness and harvest date in diverse apple accessions.


Stroke ◽  
2020 ◽  
Vol 51 (12) ◽  
pp. 3751-3755
Author(s):  
Jiang Li ◽  
Vida Abedi ◽  
Ramin Zand ◽  
Christoph J. Griessenauer ◽  

Background and Purpose: The purpose of this study was to replicate the top loci associated with white matter hyperintensity (WMH) phenotypes identified by large genome-wide association studies and the loci identified from the previous candidate gene studies. Methods: A total of 946 Geisinger MyCode patients with acute ischemic stroke with validated European ancestry and magnetic resonance imaging data were included in this study. Log-transformed WMH volume, as a quantitative trait, was calculated by a fully automated quantification process. The genome-wide association studies was carried out by a linear mixed regression model (GEMMA). A candidate-single nucleotide polymorphism analysis by including known single nucleotide polymorphisms, reported from a meta-analysis and several large GWAS for WMH, was conducted in all cases and binary converted extreme cases. Results: No genome-wide significantly associated variants were identified. In a candidate-single nucleotide polymorphism study, rs9515201 ( COL4A2 ) and rs3744028 ( TRIM65 ), 2 known genetic loci, showed nominal or trend of association with the WMH volume (β=0.13 and P =0.001 for rs9515201; β=0.094 and P =0.094 for rs3744028), and replicated in a subset of extreme cases versus controls (odds ratio=1.78, P =7.74×10 − 4 for rs9515201; odds ratio=1.53, P =0.047 for rs3744028, respectively). MTHFR677 cytosine/thymine (rs1801133) also showed an association with the binary WMH with odds ratio=1.47 for T allele ( P =0.019). Conclusions: Replication of COL4A1/2 associated with WMH reassures that the genetic risk factors for monogenic and polygenic ischemic stroke are shared at gene level.


2019 ◽  
Author(s):  
Sierra S Nishizaki ◽  
Natalie Ng ◽  
Shengcheng Dong ◽  
Robert S Porter ◽  
Cody Morterud ◽  
...  

Abstract Motivation Genome-wide association studies have revealed that 88% of disease-associated single-nucleotide polymorphisms (SNPs) reside in noncoding regions. However, noncoding SNPs remain understudied, partly because they are challenging to prioritize for experimental validation. To address this deficiency, we developed the SNP effect matrix pipeline (SEMpl). Results SEMpl estimates transcription factor-binding affinity by observing differences in chromatin immunoprecipitation followed by deep sequencing signal intensity for SNPs within functional transcription factor-binding sites (TFBSs) genome-wide. By cataloging the effects of every possible mutation within the TFBS motif, SEMpl can predict the consequences of SNPs to transcription factor binding. This knowledge can be used to identify potential disease-causing regulatory loci. Availability and implementation SEMpl is available from https://github.com/Boyle-Lab/SEM_CPP. Supplementary information Supplementary data are available at Bioinformatics online.


2008 ◽  
Vol 6 ◽  
pp. CIN.S966 ◽  
Author(s):  
Stefan Stefanov ◽  
James Lautenberger ◽  
Bert Gold

We developed an efficient pipeline to analyze genome-wide association study single nucleotide polymorphism scan results. Perl scripts were used to convert genotypes called using the BRLMM algorithm into a modified PB format. We computed summary statistics characteristic of our case and control populations including allele counts, missing values, heterozygosity, measures of compliance with Hardy-Weinberg equilibrium, and several population difference statistics. In addition, we computed association tests, including exact tests of association for genotypes, alleles, the Cochran-Armitage linear trend test, and dominant, recessive, and overdominant models at every single nucleotide polymorphism (SNP). In addition, pairwise linkage disequilbrium statistics were elaborated, using the command line version of HaploView, which was possible by writing a reformatting script. Additional Perl scripts permit loading the results into a MySQL database conjoined with a Generic Genome Browser (gbrowse) for comprehensive visualization. This browser incorporates a download feature that provides actual case and control genotypes to users in associated genomic regions. Thus, re-analysis “on the fly” is possible for casual browser users from anywhere on the Internet.


Human Cell ◽  
2021 ◽  
Vol 34 (2) ◽  
pp. 293-299
Author(s):  
Makoto Kawaguchi ◽  
Akiyoshi Nakayama ◽  
Yuka Aoyagi ◽  
Takahiro Nakamura ◽  
Seiko Shimizu ◽  
...  

AbstractGout is a common type of acute arthritis that results from elevated serum uric acid (SUA) levels. Recent genome-wide association studies (GWASs) have revealed several novel single nucleotide polymorphism (SNPs) associated with SUA levels. Of these, rs10821905 of A1CF and rs1178977 of BAZ1B showed the greatest and the second greatest significant effect size for increasing SUA level in the Japanese population, but their association with gout is not clear. We examined their association with gout using 1411 clinically-defined Japanese gout patients and 1285 controls, and meta-analyzed our previous gout GWAS data to investigate any association with gout. Replication studies revealed both SNPs to be significantly associated with gout (P = 0.0366, odds ratio [OR] with 95% confidence interval [CI]: 1.30 [1.02–1.68] for rs10821905 of A1CF, P = 6.49 × 10–3, OR with 95% CI: 1.29 [1.07–1.55] for rs1178977 of BAZ1B). Meta-analysis also revealed a significant association with gout in both SNPs (Pmeta = 3.16 × 10–4, OR with 95% CI: 1.39 [1.17–1.66] for rs10821905 of A1CF, Pmeta = 7.28 × 10–5, OR with 95% CI 1.32 [1.15–1.51] for rs1178977 of BAZ1B). This study shows the first known association between SNPs of A1CF, BAZ1B and clinically-defined gout cases in Japanese. Our results also suggest a shared physiological/pathophysiological background between several populations, including Japanese, for both SUA increase and gout susceptibility. Our findings will not only assist the elucidation of the pathophysiology of gout and hyperuricemia, but also suggest new molecular targets.


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