Limits...
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 mean offspring sex ratio (male offspring/total offspring number) of single foundress in five fig wasp species (mean ± SD):(a) deposition within the first one hour; (b) deposition over their lifespan. The average foundress number per syconium differs greatly among the five species in literatures464748: Ceratosolen gravelyi:1.60 ± 0.10, n = 168; Ceratosolen solmsi: 2.08 ± 1.65, N = 182; Eupristina koningsbergeri: 2.73 ± 1.56, N = 90; C. fusciceps: 4.50 ± 4.16, N = 1590; Ceratosolen emarginatus: 8.62 ± 16.21, N = 55. The sample size N ≥ 20 in each type of the experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4543974&req=5

f2: The mean offspring sex ratio (male offspring/total offspring number) of single foundress in five fig wasp species (mean ± SD):(a) deposition within the first one hour; (b) deposition over their lifespan. The average foundress number per syconium differs greatly among the five species in literatures464748: Ceratosolen gravelyi:1.60 ± 0.10, n = 168; Ceratosolen solmsi: 2.08 ± 1.65, N = 182; Eupristina koningsbergeri: 2.73 ± 1.56, N = 90; C. fusciceps: 4.50 ± 4.16, N = 1590; Ceratosolen emarginatus: 8.62 ± 16.21, N = 55. The sample size N ≥ 20 in each type of the experiments.

Mentions: Results indicated that, as was the case for a number of other reports on fig wasp reproduction1020212223, all of the pollinator wasps (i.e. Ceratosolen fusciceps hosted by Ficus racemosa, Ceratosolen solmsi hosted by F. hispida, Eupristina koningsbergeri hosted by F. benjamina, Ceratosolen gravelyi hosted by F. semicordata, C. emarginatus hosted by F. auriculata) tend to lay their male eggs prior to the female eggs (Fig. 1). In all of these treated pollinator species, the male offspring proportion per foundress was 66.1%–70.1%, within the first hour of deposition. The proportion of male offspring for each foundress decrease with an increase in the length of egg deposition time and the proportion of male offspring of each foundress over its lifespan range from 14.0% to 21.0% in the controlled experiments. The male offspring proportions within the first one hour of egg deposition were, however, very similar in these five treated pollinator species (Fig. 2). In these five pollinator species, the averaged foundress numbers per syconium vary from 1.60 ± 0.10 (E. koningsbergeri)to 8.62 ± 16.21 (C. emarginatus) (mean ± SD), however, sex ratio of one foundress in the controlled experiment showed that the male offspring proportion do not increase in the species with higher averaged foundress number (Fig. 2b). The data in these five species do not conform to that higher inbreeding value (i.e., lower averaged foundress number per syconium) will lead to lower male proportion in wasp offspring predicted in the Hamilton’s sex ratio evolution theory (see the appendix).


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

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

The mean offspring sex ratio (male offspring/total offspring number) of single foundress in five fig wasp species (mean ± SD):(a) deposition within the first one hour; (b) deposition over their lifespan. The average foundress number per syconium differs greatly among the five species in literatures464748: Ceratosolen gravelyi:1.60 ± 0.10, n = 168; Ceratosolen solmsi: 2.08 ± 1.65, N = 182; Eupristina koningsbergeri: 2.73 ± 1.56, N = 90; C. fusciceps: 4.50 ± 4.16, N = 1590; Ceratosolen emarginatus: 8.62 ± 16.21, N = 55. 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

f2: The mean offspring sex ratio (male offspring/total offspring number) of single foundress in five fig wasp species (mean ± SD):(a) deposition within the first one hour; (b) deposition over their lifespan. The average foundress number per syconium differs greatly among the five species in literatures464748: Ceratosolen gravelyi:1.60 ± 0.10, n = 168; Ceratosolen solmsi: 2.08 ± 1.65, N = 182; Eupristina koningsbergeri: 2.73 ± 1.56, N = 90; C. fusciceps: 4.50 ± 4.16, N = 1590; Ceratosolen emarginatus: 8.62 ± 16.21, N = 55. The sample size N ≥ 20 in each type of the experiments.
Mentions: Results indicated that, as was the case for a number of other reports on fig wasp reproduction1020212223, all of the pollinator wasps (i.e. Ceratosolen fusciceps hosted by Ficus racemosa, Ceratosolen solmsi hosted by F. hispida, Eupristina koningsbergeri hosted by F. benjamina, Ceratosolen gravelyi hosted by F. semicordata, C. emarginatus hosted by F. auriculata) tend to lay their male eggs prior to the female eggs (Fig. 1). In all of these treated pollinator species, the male offspring proportion per foundress was 66.1%–70.1%, within the first hour of deposition. The proportion of male offspring for each foundress decrease with an increase in the length of egg deposition time and the proportion of male offspring of each foundress over its lifespan range from 14.0% to 21.0% in the controlled experiments. The male offspring proportions within the first one hour of egg deposition were, however, very similar in these five treated pollinator species (Fig. 2). In these five pollinator species, the averaged foundress numbers per syconium vary from 1.60 ± 0.10 (E. koningsbergeri)to 8.62 ± 16.21 (C. emarginatus) (mean ± SD), however, sex ratio of one foundress in the controlled experiment showed that the male offspring proportion do not increase in the species with higher averaged foundress number (Fig. 2b). The data in these five species do not conform to that higher inbreeding value (i.e., lower averaged foundress number per syconium) will lead to lower male proportion in wasp offspring predicted in the Hamilton’s sex ratio evolution theory (see the appendix).

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