The interplay of demography and selection during maize domestication and expansion

Genome Biology

Li Wang¹  Matthew B. Hufford¹  Timothy M. Beissinger²  Anne Lorant²  Claudia Ross-Ibarra²  Jeffrey Ross-Ibarra² 

[1] Department of Ecology, Evolution, and Organismal Biology, Iowa State University;Department of Plant Sciences, University of California;

关键词: Demography;    Domestication;    Genetic load;    Maize;   

DOI  :  10.1186/s13059-017-1346-4

来源: DOAJ

【 摘 要 】

Abstract Background The history of maize has been characterized by major demographic events, including population size changes associated with domestication and range expansion, and gene flow with wild relatives. The interplay between demographic history and selection has shaped diversity across maize populations and genomes. Results We investigate these processes using high-depth resequencing data from 31 maize landraces spanning the pre-Columbian distribution of maize, and four wild teosinte individuals (Zea mays ssp. parviglumis). Genome-wide demographic analyses reveal that maize experienced pronounced declines in effective population size due to both a protracted domestication bottleneck and serial founder effects during post-domestication spread, while parviglumis in the Balsas River Valley experienced population growth. The domestication bottleneck and subsequent spread led to an increase in deleterious alleles in the domesticate compared to the wild progenitor. This cost is particularly pronounced in Andean maize, which has experienced a more dramatic founder event compared to other maize populations. Additionally, we detect introgression from the wild teosinte Zea mays ssp. mexicana into maize in the highlands of Mexico, Guatemala, and the southwestern USA, which reduces the prevalence of deleterious alleles likely due to the higher long-term effective population size of teosinte. Conclusions These findings underscore the strong interaction between historical demography and the efficiency of selection and illustrate how domesticated species are particularly useful for understanding these processes. The landscape of deleterious alleles and therefore evolutionary potential is clearly influenced by recent demography, a factor that could bear importantly on many species that have experienced recent demographic shifts.

【 授权许可】

Unknown