Genetical Research

Quantitative trait locus mapping of fitness-related traits in Drosophila melanogaster

M. L. WAYNE a1c1p1, J. B. HACKETT a1, C. L. DILDA a1, S. V. NUZHDIN a2, E. G. PASYUKOVA a3 and T. F. C. MACKAY a1
a1 Department of Genetics, Box 7614, North Carolina State University, Raleigh, NC 27695, USA
a2 Section of Evolution and Ecology, Division of Biological Sciences, 3206 Storer Hall, University of California Davis, Davis, CA, USA
a3 Institute of Molecular Genetics of the Russian Academy of Science, Kurchatov Square, Moscow 123182, Russia


We examined the genetic architecture of four fitness-related traits (reproductive success, ovariole number, body size and early fecundity) in a panel of 98 Oregon-R × 2b3 recombinant inbred lines (RILs). Highly significant genetic variation was observed in this population for female, but not male, reproductive success. The cross-sex genetic correlation for reproductive success was 0·20, which is not significantly different from zero. There was significant genetic variation segregating in this cross for ovariole number, but not for body size or early fecundity. The RILs were genotyped for cytological insertion sites of roo transposable elements, yielding 76 informative markers with an average spacing of 3·2 cM. Quantitative trait loci (QTL) affecting female reproductive success and ovariole number were mapped using a composite interval mapping procedure. QTL for female reproductive success were located at the tip of the X chromosome between markers at cytological locations 1B and 3E; and on the left arm of chromosome 2 in the 30D–38A cytological region. Ovariole number QTL mapped to cytological intervals 62D–69D and 98A–98E, both on the third chromosome. The regions harbouring QTL for female reproductive success and ovariole number were also identified as QTL for longevity in previous studies with these lines.

(Received March 10 1999)
(Revised May 24 2000)
(Revised September 21 2000)

c1 Corresponding author.
p1 Present address: Department of Zoology, Box 118525, University of Florida, Gainesville, FL 32611-8525, USA.