Genetic architecture of a wing size measure in Drosophila hibisci from two populations in eastern Australia.
Two models of evolutionary change invoke either additive genetic contributions to phenotypic traits (Fisher) or epistatic as well as additive effects (Wright). An earlier study of the flower-breeding Drosophila hibisci from two sites in eastern Australia reported additive and epistatic genetic effects as well as environmental effects on ovariole number. The present study of the same flies examines the genetic architecture of wing width, a trait that is correlated phenotypically with ovariole number and body size. A generation means analysis of flies reared at 25 degrees C indicated additive and epistatic genetic effects, but no consistent maternal effects, whereas for flies reared at three temperatures (18 degrees C, 21.5 degrees C, and 25 degrees C) linear and nonlinear environmental effects interacted with additive genetic effects. The genetic correlation matrix for ovariole number and wing width suggested negative genetic correlations between additive effects on one trait and epistatic effects on the other. Both traits provide evidence of genetic effects consistent with assumptions of Wright's shifting balance theory of evolution.
Department of Biology, Syracuse University, Syracuse, NY 13244-1270, U.S.A. llwolf@mailbox.syr.edu
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Wolf
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Starmer
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Polak
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Barker
D000818:Animals; D001315:Australia; D001830:Body Surface Area; D001835:Body Weight / Q000235:genetics; D003433:Crosses, Genetic; D004330:Drosophila / Q000033:anatomy & histology* / Q000235:genetics*; D004777:Environment; D005260:Female; D008297:Male; D009929:Organ Size / Q000235:genetics; D013696:Temperature; D014921:Wings, Animal / Q000033:anatomy & histology*