Sexual traits are sensitive to genetic stress and predict extinction risk in the stalk-eyed fly, Diasemopsis meigenii.
Bottom Line: However, this hypothesis has received little testing and results are inconsistent.This heterosis was greater in male eyespan than in male wing length, but not female eyespan.The elevated response in male eyespan to genetic stress mirrored the result found using environmental stress during larval development and suggests that common mechanisms underlie the patterns observed.
Affiliation: Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, United Kingdom.Show MeSH
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Mentions: A total of 68 families were set up (34 inbred and 34 outbred). In total, 976 flies were measured: 481 females (237 inbreds and 244 outbreds) and 495 males (244 inbreds and 251 outbreds). Analysis was performed by pooling all flies and comparing inbred and outbred means. Evidence of heterosis was inferred if outbred trait means were significantly larger than inbred trait means. Male and female thorax length was higher in outbred flies than inbred flies (males, = 0.027, F1,25.5 = 15.280, P < 0.001; females, = 0.019, F1,28.1 = 8.495, P = 0.007; Fig.3A). The same was also true for absolute eyespan (males, = 0.030, F1,30.8 = 11.964, P = 0.002; females, = 0.028, F1,29.1 = 10.084, P = 0.004) and relative eyespan (males, = 0.018, F1,31.1 = 5.256, P = 0.029; females, = 0.019, F1,28.0 = 7.794, P = 0.009; Fig.3B). Absolute wing length followed a similar pattern (males, = 0.020, F1,29.9 = 7.749, P = 0.009; females, = 0.023, F1,31.4 = 11.986, P = 0.002). However, after controlling for thorax length, only female relative wing length still showed evidence of inbreeding depression (males, = 0.011, F1,31.5 = 3.047, P = 0.091; females, = 0.017, F1,31.4 = 9.967, P = 0.004; Fig.3C).
Affiliation: Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, United Kingdom.