Filling in the Blanks - Inferring Genetic Relationships Between Individuals Based on Incomplete Information

Steven Miller
University of Auckland

Grant Harper
Department of Conservation

James Russell
University of Auckland

Hamish MacInnes
University of Auckland

Rachel Fewster
University of Auckland

A common method for inferring individuals’ genetic relationships is to calculate the probability each individual is a member of each of a set of potential populations. This is achieved most simply by building population allele profiles based on individuals sampled from that population, then using the Hardy-Weinberg Equilibrium equations to calculate the probability that individuals’ genotypes could have been drawn from those genetic profiles. The individuals’ sets of probabilities can then be used to characterise groups of genetically similar individuals. However, these relative comparisons are invalid if individuals possess different levels of completeness for the selected genetic traits. It is not always feasible to characterise every individual for every genetic trait selected for the analysis. We present a novel method for inferring an individual’s complete- information probability of belonging to a population when that individual has an incomplete set of genetic information. We apply this method to data from a Rattus sp. post-eradication repopulation scenario from Pearl Island, Stewart Island (Rakiura), New Zealand. In this scenario, the reappearance of rats following eradication needed to be identified as a reinvasion from the surrounding mainland, or a failed eradication on the island itself.

Session 3a, Statistical Genomics: 11:50 — 12:10, Room 445

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