Hybrid Horizons: Screening Hybridisation Through Nuclear Environmental DNA

Area of Science:

• Evolutionary Biology
• Conservation Genetics
• Environmental Science

Background:

• Monitoring hybrid zones is crucial for understanding evolution and preventing species loss.
• Traditional methods for hybrid zone monitoring are often impractical due to cost, time, and difficulty sampling rare species.
• Nuclear environmental DNA (eDNA) is scarce but essential for hybridisation studies, with its application previously untested.

Purpose of the Study:

• To empirically validate the use of nuclear eDNA for screening hybrid populations.
• To develop and test an eDNA-based toolkit for genotyping nuclear single nucleotide polymorphisms (SNPs) without sequencing.
• To assess the concordance between eDNA-derived ancestry estimates and individual genotypes in a controlled setting.

Main Methods:

• Developed an eDNA toolkit using Kompetitive Allele-Specific PCR (KASP) to genotype species-diagnostic nuclear SNPs.
• Quantified ancestry levels by mapping fluorescence data to a hybrid index.
• Compared eDNA-derived ancestry estimates with skin-swab genotypes from crested newts (Triturus ivanbureschi and T. macedonicus) and their F1 hybrids in mesocosms.

Main Results:

• Demonstrated strong concordance between eDNA-based ancestry estimates and individual genotypes.
• The eDNA approach proved effective across different eDNA sampling concentrations.
• Successfully validated nuclear eDNA as a viable tool for hybrid population screening.

Conclusions:

• Nuclear eDNA analysis, coupled with KASP genotyping, provides a powerful, non-invasive method for hybrid zone screening.
• This toolkit offers a fast, cost-efficient, and scalable complement to conventional methods for biodiversity monitoring and conservation.
• The approach is well-suited for locating and tracking hybrid zones, aiding in evolutionary and conservation efforts.