Advanced intercross lines, an experimental population for fine genetic mapping.

TLDR

Advanced intercross lines (AILs) increase recombination probability and stretch the genetic map, thereby providing higher QTL mapping resolution than conventional populations. The authors propose using AILs derived from known inbred lines as a resource for fine genetic mapping. AILs are generated by successive random intercrosses starting from an initial cross between two inbred lines. By the tenth generation, the 95 % confidence interval for a QTL shrinks fivefold compared to F2, and simulations show that maintaining an effective population size of at least 100 individuals per generation is required to achieve this precision.

Abstract

Abstract An advanced intercrossed line (AIL) is an experimental population that can provide more accurate estimates of quantitative trait loci (QTL) map location than conventional mapping populations. An AIL is produced by randomly and sequentially intercrossing a population that initially originated from a cross between two inbred lines or some variant thereof. This provides increasing probability of recombination between any two loci. Consequently, the genetic length of the entire genome is stretched, providing increased mapping resolution. In this way, for example, with the same population size and QTL effect, a 95% confidence interval of QTL map location of 20 cM in the F2 is reduced fivefold after eight additional random mating generations (F10). Simulation results showed that to obtain the anticipated reduction in the confidence interval, breeding population size of the AIL in all generations should comprise an effective number of > or = 100 individuals. It is proposed that AILs derived from crosses between known inbred lines may be a useful resource for fine genetic mapping.