Abstract
Next-generation sequencing (NGS) technologies have made it possible to address population genetic questions in almost any system, but high error rates associated with such data can introduce significant biases into downstream analyses, necessitating careful experimental design and interpretation in studies based on short-read sequencing. Exploration of population genetic analyses based on NGS has revealed some of the potential biases, but previous work has emphasized parameters relevant to human population genetics and further examination of parameters relevant to other systems is necessary, including situations where sample sizes are small and genetic variation is high. To assess experimental power to address several principal objectives of population genetic studies under these conditions, we simulated population samples under selective sweep, population growth, and population subdivision models and tested the power to accurately infer population genetic parameters from sequence polymorphism data obtained through simulated 4×, 8×, and 15× read depth sequence data. We found that estimates of population genetic differentiation and population growth parameters were systematically biased when inference was based on 4× sequencing, but biases were markedly reduced at even 8× read depth. We also found that the power to identify footprints of positive selection depends on an interaction between read depth and the strength of selection, with strong selection being recovered consistently at all read depths, but weak selection requiring deeper read depths for reliable detection. Although we have explored only a small subset of the many possible experimental designs and population genetic models, using only one SNP-calling approach, our results reveal some general patterns and provide some assessment of what biases could be expected under similar experimental structures.
Highlights
Principal objectives in population genetics are to identify targets of natural selection, infer historical shifts in demography, and define genetic differentiation among groups
SNP RECOVERY To quantify the effect of short-read sequencing on the power to infer population genetic models, we simulated a typical empirical re-sequencing pipeline including sequencing and SNP-calling errors inherent to such experimental frameworks
For all population genetic models, short-read datasets were generated at three read depths, aligned to a simulated reference, and queried for SNPs
Summary
Principal objectives in population genetics are to identify targets of natural selection, infer historical shifts in demography, and define genetic differentiation among groups. The relative low cost and high throughput nature of NGS technologies has made it possible to collect full genome sequence data on population samples, providing the opportunity to address population genetic questions at the genomic scale, sometimes across multiple populations (e.g., Xia et al, 2009; Durbin et al, 2010; Magwene et al, 2011). Population genomic experiments in ecological and other non-model systems www.frontiersin.org
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.