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Non-quantitative adjustment of offspring sex ratios in pollinating fig wasps.

Wang RW, Sun BF, He JZ, Dunn DW - Sci Rep (2015)

Bottom Line: The foundresses tend to deposit their male eggs prior to female eggs.The observed increase in the proportion of male offspring as a function of foundress number results from density-dependent interference competition among the foundresses.The results here implied that genetic adjustment mechanisms of the sex ratio of fig wasps can only be triggered to be on or off and that the foundresses can not quantitatively adjust their sex ratio according to increased environmental selection pressure.

View Article: PubMed Central - PubMed

Affiliation: Center for Ecological and Environmental Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.

ABSTRACT
Fig wasp is one of the most well known model systems in examining whether or not the parents could adjust their offspring sex ratio to maximize their gene frequency transmission in next generations. Our manipulative experiments showed that, in all of the five pollinator wasps of figs (Agaonidae) that have different averages of foundress numbers per syconium, almost the same proportions of male offspring are produced in the experiment that foundresses deposit one hour then are killed with ether (66.1%-70.1%) and over the lifespan of each foundress (14.0%-21.0%). The foundresses tend to deposit their male eggs prior to female eggs. The observed increase in the proportion of male offspring as a function of foundress number results from density-dependent interference competition among the foundresses. These results showed that the selection of gene frequency transmission through the behavioral adjustment in the evolution of sex ratio does not exist in these five fig wasps. The results here implied that genetic adjustment mechanisms of the sex ratio of fig wasps can only be triggered to be on or off and that the foundresses can not quantitatively adjust their sex ratio according to increased environmental selection pressure.

No MeSH data available.


Related in: MedlinePlus

The galled flower numbers (egg number) in the experiments of simultaneous introduction of foundresses and the experiments of sequential introduction of fundresses with different foundress number in four species (mean ± SD).The sample size N ≥ 20 in each type of the experiments.
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f3: The galled flower numbers (egg number) in the experiments of simultaneous introduction of foundresses and the experiments of sequential introduction of fundresses with different foundress number in four species (mean ± SD).The sample size N ≥ 20 in each type of the experiments.

Mentions: The experiment results showed, when nine foundresses were compared, that the sequential introduction experiments have higher averaged offspring numbers than in simultaneous introduction (Fig. 3). The mean comparison results are: in F. benjamina (foundress number = 7), t = 21.231, df = 38, P < 0.001; in F. semicordata, t = 15.420, df = 38, P < 0.001; in F. hispida, t = 20.626, df = 38, P < 0.001; in Ficus racemosa, t = 4.56, df = 39, P < 0.001. Interference competition is more significant when the foundress number is relatively high and the interference competition is weak or does not exist when the foundress number is low. For the sake of brevity, we do not show all the comparison results in this paper.


Non-quantitative adjustment of offspring sex ratios in pollinating fig wasps.

Wang RW, Sun BF, He JZ, Dunn DW - Sci Rep (2015)

The galled flower numbers (egg number) in the experiments of simultaneous introduction of foundresses and the experiments of sequential introduction of fundresses with different foundress number in four species (mean ± SD).The sample size N ≥ 20 in each type of the experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543974&req=5

f3: The galled flower numbers (egg number) in the experiments of simultaneous introduction of foundresses and the experiments of sequential introduction of fundresses with different foundress number in four species (mean ± SD).The sample size N ≥ 20 in each type of the experiments.
Mentions: The experiment results showed, when nine foundresses were compared, that the sequential introduction experiments have higher averaged offspring numbers than in simultaneous introduction (Fig. 3). The mean comparison results are: in F. benjamina (foundress number = 7), t = 21.231, df = 38, P < 0.001; in F. semicordata, t = 15.420, df = 38, P < 0.001; in F. hispida, t = 20.626, df = 38, P < 0.001; in Ficus racemosa, t = 4.56, df = 39, P < 0.001. Interference competition is more significant when the foundress number is relatively high and the interference competition is weak or does not exist when the foundress number is low. For the sake of brevity, we do not show all the comparison results in this paper.

Bottom Line: The foundresses tend to deposit their male eggs prior to female eggs.The observed increase in the proportion of male offspring as a function of foundress number results from density-dependent interference competition among the foundresses.The results here implied that genetic adjustment mechanisms of the sex ratio of fig wasps can only be triggered to be on or off and that the foundresses can not quantitatively adjust their sex ratio according to increased environmental selection pressure.

View Article: PubMed Central - PubMed

Affiliation: Center for Ecological and Environmental Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.

ABSTRACT
Fig wasp is one of the most well known model systems in examining whether or not the parents could adjust their offspring sex ratio to maximize their gene frequency transmission in next generations. Our manipulative experiments showed that, in all of the five pollinator wasps of figs (Agaonidae) that have different averages of foundress numbers per syconium, almost the same proportions of male offspring are produced in the experiment that foundresses deposit one hour then are killed with ether (66.1%-70.1%) and over the lifespan of each foundress (14.0%-21.0%). The foundresses tend to deposit their male eggs prior to female eggs. The observed increase in the proportion of male offspring as a function of foundress number results from density-dependent interference competition among the foundresses. These results showed that the selection of gene frequency transmission through the behavioral adjustment in the evolution of sex ratio does not exist in these five fig wasps. The results here implied that genetic adjustment mechanisms of the sex ratio of fig wasps can only be triggered to be on or off and that the foundresses can not quantitatively adjust their sex ratio according to increased environmental selection pressure.

No MeSH data available.


Related in: MedlinePlus