Corrigenda: Experimental Studies of Gene Frequencies in Very Small Populations of Drosophila melanogaster: I. Forked

Evolution ◽  
1955 ◽  
Vol 9 (1) ◽  
pp. 105
Author(s):  
Warwick E. Kerr









1993 ◽  
Vol 62 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Sergey V. Nuzhdin ◽  
Peter D. Keightley ◽  
Elena G. Pasyukova

SummaryHitch-hiking of dispersed mobile elements serving as molecular markers was used as a new tool for mapping quantitative trait loci in Drosophila melanogaster. Two Drosophila strains with high fitness (HA) were backcrossed repeatedly to a closely related strain with low fitness (LA) to initiate experimental populations with expected HA gene frequencies of 1/32. The frequencies of 19 insertion sites of the retrotransposons mdg1 and copia were analyzed after 11 to 17 generations. Frequencies of sites from the HA line increased substantially in the pericentromeric region, indicating that one or more loci responsible for the fitness difference between the strains were located there. A maximum likelihood (ML) procedure was applied to estimate selection coefficients associated with the markers, and this indicated a broad, strongly selected region of the chromosome. At least one additional locus was localized in the middle of the 2L arm. Possible applications of this method are discussed.



2019 ◽  
Vol 286 (1902) ◽  
pp. 20190226 ◽  
Author(s):  
Patrick Joye ◽  
Tadeusz J. Kawecki

Resistance to pathogens is often invoked as an indirect benefit of female choice, but experimental evidence for links between father's sexual success and offspring resistance is scarce and equivocal. Two proposed mechanisms might generate such links. Under the first, heritable resistance to diverse pathogens depends on general immunocompetence; owing to shared condition dependence, male sexual traits indicate immunocompetence independently of the male's pathogen exposure. By contrast, other hypotheses (e.g. Hamilton–Zuk) assume that sexual traits only reveal heritable resistance if the males have been exposed to the pathogen. The distinction between the two mechanisms has been neglected by experimental studies. We show that Drosophila melanogaster males that are successful in mating contests (one female with two males) sire sons that are substantially more resistant to the intestinal pathogen Pseudomonas entomophila —but only if the males have themselves been exposed to the pathogen before the mating contest. By contrast, sons of males sexually successful in the absence of pathogen exposure are less resistant than sons of unsuccessful males. We detected no differences in daughters’ resistance. Thus, while sexual selection may have considerable consequences for offspring resistance, these consequences may be sex-specific. Furthermore, contrary to the ‘general immunocompetence’ hypothesis, these consequences can be positive or negative depending on the epidemiological context under which sexual selection operates.



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