A new preprint from the Hoekstra lab at Harvard makes great use of the double digest RAD-seq protocol to better understand reproductive barriers and speciation in closely related species of mice. Since it was the Hoekstra lab that gave us the ddRAD-seq method, we took notice when this preprint became available.
The paper comes from Hopi Hoekstra and Emily Delaney, a Harvard grad student who is now a postdoctoral fellow at the University of California, Davis. In “Sexual imprinting and speciation in two Peromyscus species,” the scientists describe how sexual imprinting, typically a learned trait, contributes to sexual isolation of Peromyscus leucopus, the white-footed mouse, and P. gossypinus, the cotton mouse.
One area of interest at the start of this project was determining the genetic or learned mechanisms underlying sexual isolation. The scientists “used genomic data to first assess hybridization in the wild and conclusively found that the two species remain genetically distinct in sympatry despite rare hybridization events,” they report. “We find that these mating preferences are learned in one species but may be genetic in the other: P. gossypinus sexually imprints on its parents, but innate biases or social learning affects mating preferences in P. leucopus.”
The study involved using ddRAD-seq to analyze 376 mice. In that workflow, the team used Pippin Prep to select fragments ranging from 265 bp to 335 bp. Libraries were sequenced with the Illumina platform.
“Our study supports an emerging view that sexual imprinting could be vital to the generation and maintenance of sexual reproductive barriers,” the authors conclude. “Examining the role of sexual imprinting in similar cases of speciation driven by sexual reproductive barriers will continue to expand our understanding of the role of behavior in speciation.”