Primer development for amplification of toll-like genes for the assessment of adaptive genetic diversity in vulnerable grassland bird species

Abstract

Assessing genetic diversity in species of conservation concern is a critical parameter to implement management plans that may increase their viability. Traditionally, genetic diversity has been assessed using neutral genes; nevertheless, recent perspectives have proposed that genetic variation under natural selection (adaptive genes) is more representative of the adaptive potential of a population or species. Toll-like receptors (TLR) are an innate immune gene family that binds to Pathogen Associated Molecular Patterns. These receptors evolved under positive selection and by coevolution; therefore, they represent adaptive genetic diversity. We designed and tested six pairs of primers that amplify TLR genes in seven grassland species, one of the most vulnerable North American bird groups. Analysis of the sequences showed that all were polymorphic and evolved under positive selection, with the exception of TLR3, which evolved neutrally. These primers may constitute a useful tool for conservation studies for grassland sparrow species.