bioRxiv Science⌕ Search

bioRxiv · 10.1101/2023.01.06.523022

Genetic diversity of North American popcorn germplasm and the effect of population structure on nicosulfuron response

Abstract

Popcorn is an important crop in the United States; however, genetic analyses of popcorn are limited and tend to utilize relatively few markers that cannot capture the total genomic variation. To improve the genomic resources in popcorn, a panel of 362 popcorn accessions was evaluated using 417,218 single nucleotide polymorphisms generated using a genotyping-by-sequencing approach. Using this genomic data, a model-based clustering analysis identified two populations. The first comprised North American Yellow Pearl Popcorns and several accessions of the Chilean Curagua landrace. The second, the Pointed and Latin American Popcorns, included all remaining North American (pointed and early popcorns), Latin American, and global accessions. The two populations exhibited large differences in population structure and genetic diversity. The North American Yellow Pearl Popcorns constitute a highly inbred population with limited genetic diversity compared to the Pointed and Latin American Popcorns. Additionally, phenotypic differences between the two populations were observed in kernel color and nicosulfuron sensitivity. A filtered set of SNPs was curated and used for genome-wide association studies and popcorn-specific candidate genes for nicosulfuron tolerance were identified. The genomic characterization described here can be used by breeding programs to accelerate the rate of genetic gain and incorporate genetic diversity into elite popcorn germplasm. Core IdeasO_LINorth American Popcorn is composed of two distinct populations that differ genetically and phenotypically. C_LIO_LINorth American Yellow Pearl Popcorns contain limited genetic diversity and are highly inbred. C_LIO_LIPointed and Latin American Popcorns exhibit considerable genetic diversity and rapid linkage disequilibrium decay. C_LIO_LIKernel color does not affect nicosulfuron sensitivity and instead reflects differences between the populations. C_LIO_LIPopcorn-specific candidate genes for nicosulfuron tolerance are distinct from dent corn. C_LI

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Sullivan, M., Williams, M. M., Studer, A. J.. 2023-01-08. Genetic diversity of North American popcorn germplasm and the effect of population structure on nicosulfuron response. https://doi.org/10.1101/2023.01.06.523022

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Large language model-based bibliometric evaluation of population descriptors in human genetics

As the use of population descriptors such as race, ethnicity, and ancestry have become increasingly common in modern genetics research, there have been growing calls to critically examine their use. Most notably, in 2023, the National Academies of Science, Engineering, and Medicine (NASEM) published a report titled Using Population Descriptors in Genetics and Genomics Research: A New Framework for an Evolving Field, which included eight specific and actionable recommendations for researchers to implement the ethical and accurate use of population descriptors in genetic research. Here, we use the 2023 NASEM report as a benchmark to analyze the use of population descriptors in genome-wide association studies (GWAS). We develop a general toolkit for large language model-based bibliometrics, operationalize the report's recommendations into an evaluation framework, and apply this framework to evaluate all 4,007 papers from the GWAS Catalog published between 2007 and 2025 with full text available on PubMedCentral. We find significant improvements in adherence to NASEM report recommendations over time. However, most improvements predate the publication of the NASEM report itself, suggesting the report functioned primarily as a synthesis of existing best practices rather than a catalyst for change. We conclude by highlighting opportunities for growth in the field of human genetics.

genetics↗

Mitigating biases of rescaling in forward-in-time population genetic simulations

Forward-in-time population genetic simulations are widely used in evolutionary analyses, but simulating large populations and long genomic regions remains computationally demanding. To reduce this cost, parameter rescaling is widely employed, in which the original evolutionary process is approximated by one with a smaller population size and fewer generations. Recently, several studies using the SLiM simulator have raised concerns about the accuracy of this rescaling approach. In this study, we show that many of the biases reported in these studies can be mitigated by using a different simulation algorithm. These results reveal that the accuracy of parameter rescaling depends on how well the simulation algorithm preserves diffusion-limit properties under rescaling.

genetics↗

OPA1 controls mitochondrial dysfunction-driven liver fibrosis in MASLD

Progressive hepatic fibrosis is the principal determinant of morbidity and mortality in metabolic dysfunction-associated steatotic liver disease and steatohepatitis (MASLD/MASH). Mitochondrial dysfunction is a hallmark of MASH, and the release of mitochondrial damage-associated molecular patterns (mito-DAMPs) from injured hepatocytes can promote fibrosis. However, how mitochondrial dynamics and quality control shape the fibrotic response in MASLD/MASH remains unclear. Here, through large-scale genomic analyses of mitochondrial genes governing mitophagy, fusion and fission in human MASLD, with a power-equivalent sample size of approximately 700,000 individuals, we identify a strong association between hepatic fibrosis and the mitochondrial fusion factor dynamin-like GTPase optic atrophy 1 (OPA1). OPA1 transcripts and protein abundance in the liver epithelium were progressively dysregulated with advancing fibrosis. In mice, hepatocyte-specific OPA1 loss alone was sufficient to induce hepatic stellate cell activation and fibrosis in zone 3, promoted the release of mito-DAMPs into the circulation and exacerbated fibrosis in experimental MASH. These findings identify OPA1 as a central regulator of the hepatic fibrotic response and connect defective mitochondrial homeostasis to mito-DAMP release, hepatic stellate cell activation and fibrosis in MASLD.

genetics↗