Using blocks of linked single nucleotide polymorphisms as highly polymorphic genetic markers for parentage analysis

Area of Science:

• Genetics
• Molecular Biology
• Evolutionary Biology

Background:

• Single nucleotide polymorphisms (SNPs) are abundant genetic markers but are typically biallelic, limiting their individual utility in parentage analysis.
• Identifying numerous unlinked SNPs can be challenging, especially in non-model organisms, hindering their application in population genetics.
• Existing methods for parentage analysis often rely on microsatellites, which may not capture the full spectrum of genomic variation.

Purpose of the Study:

• To investigate the efficacy of using linked single nucleotide polymorphisms (SNPs) as multi-SNP haplotypes for reconstructing male genotypes in parentage analysis.
• To develop a novel molecular marker system that overcomes the limitations of individual biallelic SNPs for high-throughput parentage testing.
• To assess the performance of these SNP-based markers against traditional microsatellite markers in terms of parent exclusion probabilities.

Main Methods:

• Inferred haplotypes for blocks of 3 to 26 linked SNPs using Haplore and Phase 2.1 software.
• Treated each multi-SNP haplotype as a distinct allele, creating a highly polymorphic marker analogous to microsatellites.
• Conducted simulation studies using empirical haplotype frequencies from Drosophila melanogaster and Mus musculus populations.

Main Results:

• Multi-SNP haplotypes demonstrated competitive single parent exclusion probabilities compared to microsatellite loci, especially when using six or more linked SNPs.
• The developed markers exhibited modest rates of missing data and genotyping/phasing errors.
• The approach proved effective for reconstructing male genotypes in simulated polyandrous organisms with varying clutch sizes.

Conclusions:

• Linked SNP blocks, when analyzed as multi-SNP haplotypes, represent a powerful and viable alternative to microsatellites for parentage and paternity analysis.
• This method is particularly advantageous for studies focusing on the functional significance of genomic polymorphisms and for non-model organisms.
• The use of multi-SNP haplotypes offers a robust strategy for genetic marker development in population and conservation genetics.