Genes Affecting Aging: Mapping Quantitative Trait Loci in Drosophila melanogaster Using Amplified Fragment Length Polymorphisms (AFLPs)

Abstract

This study examines the use of AFLPs (amplified fragment length polymorphisms) for locating QTL for longevity. Inbred long and short-lived lines from selected stocks of D. melanogaster were backcrossed and measurements of life span compiled into a distribution. AFLP markers assorting with long life were screened from the extremes of that distribution. To test their association with further recombination, a second F₁ was backcrossed for three generations and measured. Sires and progeny were genotyped for the markers initially screened. Three AFLP primer pairs identified markers assorting with long life in six of 48 sires. An a posteriori test showed that families of sires with putative markers lived significantly longer on average. A second test showed that within families, progeny with markers lived significantly longer than sibs without them. Marker positions were mapped by hybridization to a P₁ genomic miniblot. AFLP markers were cloned, sequenced and matched to known genomic sequences in a BLAST search. Positions were compared to QTL known from other studies. The BLAST search indicated hybridization at multiply dispersed sites throughout the genome. Marker positions also corresponded to many from independent QTL maps. These results indicate that some QTL consist of dispersed duplications that contribute independently to longevity.