The pattern and distribution of deleterious mutations in maize

Area of Science:

• Genetics
• Plant Biology
• Evolutionary Biology

Background:

• Nonsynonymous mutations are typically deleterious and removed by natural selection.
• Deleterious alleles can impact complex traits but are hard to study due to low frequencies.
• Population genetics factors like selection and drift influence deleterious allele evolution.

Purpose of the Study:

• To characterize deleterious variants in maize using genome-wide data.
• To investigate the frequency and distribution of deleterious single nucleotide polymorphisms (SNPs).
• To assess the role of deleterious variants in complex traits and heterosis.

Main Methods:

• Utilized genome-wide genotyping data from a large maize inbred line panel.
• Analyzed single nucleotide polymorphism (SNP) data to identify putatively deleterious variants.
• Examined the association of deleterious variants with complex traits and population structure.

Main Results:

• Most putatively deleterious SNPs were found at low frequencies within maize genetic groups, despite inbreeding.
• Genes linked to complex traits showed enrichment for deleterious variants.
• The findings align with the dominance model of heterosis.

Conclusions:

• Deleterious variants are common in maize and often maintained at low frequencies.
• These variants contribute to the genetic basis of complex traits.
• The complementation of low-frequency deleterious variants likely drives hybrid vigor in maize.