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Reproductive behaviour evolves rapidly when intralocus sexual conflict is removed.

Bedhomme S, Prasad NG, Jiang PP, Chippindale AK - PLoS ONE (2008)

Bottom Line: On the other hand, our data suggest that females expressing the ML genomes had reduced attractiveness, stimulating a lower rate of courtship from males.Moreover, females expressing ML genomes tend to display reduced yeast-feeding behaviour, which is probably linked to the reduction of their fecundity.These results suggest that reproductive behaviour is shaped by opposing selection on males and females, and that loci influencing attractiveness and foraging were polymorphic for alleles with sexually antagonistic expression patterns prior to ML selection.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada. sbedh_01@uni-muenster.de

ABSTRACT

Background: Intralocus sexual conflict can inhibit the evolution of each sex towards its own fitness optimum. In a previous study, we confirmed this prediction through the experimental removal of female selection pressures in Drosophila melanogaster, achieved by limiting the expression of all major chromosomes to males. Compared to the control populations (C(1-4)) where the genomes are exposed to selection in both sexes, the populations with male-limited genomes (ML(1-4)) showed rapid increases in male fitness, whereas the fitness of females expressing ML-evolved chromosomes decreased.

Methodology/principal findings: Here we examine the behavioural phenotype underlying this sexual antagonism. We show that males expressing the ML genomes have a reduced courtship level but acquire the same number of matings. On the other hand, our data suggest that females expressing the ML genomes had reduced attractiveness, stimulating a lower rate of courtship from males. Moreover, females expressing ML genomes tend to display reduced yeast-feeding behaviour, which is probably linked to the reduction of their fecundity.

Conclusion/significance: These results suggest that reproductive behaviour is shaped by opposing selection on males and females, and that loci influencing attractiveness and foraging were polymorphic for alleles with sexually antagonistic expression patterns prior to ML selection. Hence, intralocus sexual conflict appears to play a role in the evolution of a wide range of fitness-related traits and may be a powerful mechanism for the maintenance of genetic variation in fitness.

Show MeSH
Number of individuals present at the yeast food source (± s.e.) when ML chromosomes (shaded bars) and C chromosomes (open bars) were expressed in females (left side) and males (right side) in vials containing individuals of both sexes.
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pone-0002187-g003: Number of individuals present at the yeast food source (± s.e.) when ML chromosomes (shaded bars) and C chromosomes (open bars) were expressed in females (left side) and males (right side) in vials containing individuals of both sexes.

Mentions: We also measured the time spent at the yeast food source, another trait identified as a potential sexually antagonistic trait. For this trait, we found no difference between ML and C males, either over the whole experiment (t3 = 0.33, p = 0.76, figure 3, table 1) or in observation periods three to seven (t3 = 1.28, p = 0.29, table 2). This absence of a difference in time spent at the yeast food source was confirmed in the “male only” vials (t3 = 0.95, p = 0.41 for the full observation time and t3 = 0.61, p = 0.59 for the observation rounds 3 to 7). In these vials, we also recorded the male-male courtship activity and found a reduced male-male courtship activity of ML males compared to the C males (t3 = 3.45, p = 0.04).


Reproductive behaviour evolves rapidly when intralocus sexual conflict is removed.

Bedhomme S, Prasad NG, Jiang PP, Chippindale AK - PLoS ONE (2008)

Number of individuals present at the yeast food source (± s.e.) when ML chromosomes (shaded bars) and C chromosomes (open bars) were expressed in females (left side) and males (right side) in vials containing individuals of both sexes.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2367451&req=5

pone-0002187-g003: Number of individuals present at the yeast food source (± s.e.) when ML chromosomes (shaded bars) and C chromosomes (open bars) were expressed in females (left side) and males (right side) in vials containing individuals of both sexes.
Mentions: We also measured the time spent at the yeast food source, another trait identified as a potential sexually antagonistic trait. For this trait, we found no difference between ML and C males, either over the whole experiment (t3 = 0.33, p = 0.76, figure 3, table 1) or in observation periods three to seven (t3 = 1.28, p = 0.29, table 2). This absence of a difference in time spent at the yeast food source was confirmed in the “male only” vials (t3 = 0.95, p = 0.41 for the full observation time and t3 = 0.61, p = 0.59 for the observation rounds 3 to 7). In these vials, we also recorded the male-male courtship activity and found a reduced male-male courtship activity of ML males compared to the C males (t3 = 3.45, p = 0.04).

Bottom Line: On the other hand, our data suggest that females expressing the ML genomes had reduced attractiveness, stimulating a lower rate of courtship from males.Moreover, females expressing ML genomes tend to display reduced yeast-feeding behaviour, which is probably linked to the reduction of their fecundity.These results suggest that reproductive behaviour is shaped by opposing selection on males and females, and that loci influencing attractiveness and foraging were polymorphic for alleles with sexually antagonistic expression patterns prior to ML selection.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada. sbedh_01@uni-muenster.de

ABSTRACT

Background: Intralocus sexual conflict can inhibit the evolution of each sex towards its own fitness optimum. In a previous study, we confirmed this prediction through the experimental removal of female selection pressures in Drosophila melanogaster, achieved by limiting the expression of all major chromosomes to males. Compared to the control populations (C(1-4)) where the genomes are exposed to selection in both sexes, the populations with male-limited genomes (ML(1-4)) showed rapid increases in male fitness, whereas the fitness of females expressing ML-evolved chromosomes decreased.

Methodology/principal findings: Here we examine the behavioural phenotype underlying this sexual antagonism. We show that males expressing the ML genomes have a reduced courtship level but acquire the same number of matings. On the other hand, our data suggest that females expressing the ML genomes had reduced attractiveness, stimulating a lower rate of courtship from males. Moreover, females expressing ML genomes tend to display reduced yeast-feeding behaviour, which is probably linked to the reduction of their fecundity.

Conclusion/significance: These results suggest that reproductive behaviour is shaped by opposing selection on males and females, and that loci influencing attractiveness and foraging were polymorphic for alleles with sexually antagonistic expression patterns prior to ML selection. Hence, intralocus sexual conflict appears to play a role in the evolution of a wide range of fitness-related traits and may be a powerful mechanism for the maintenance of genetic variation in fitness.

Show MeSH