Effective population size in Hymenoptera with complementary sex determination

Area of Science:

• Evolutionary genetics
• Population genetics
• Hymenoptera biology

Background:

• Haplodiploid insects like Hymenoptera have a unique sex determination system.
• Homozygosity at the sex-determining locus results in diploid males, which are often inviable or sterile.
• Diploid male production impacts population structure and effective population size (Ne).

Purpose of the Study:

• To theoretically assess the impact of diploid male production on the effective population size (Ne) in Hymenoptera.
• To compare the effects of inviable versus effectively sterile diploid males on Ne.
• To investigate the role of allelic diversity at the sex-determining locus.

Main Methods:

• Theoretical modeling of population genetics.
• Analysis of sex determination systems in haplodiploid organisms.
• Simulation of population dynamics under different scenarios of diploid male viability.

Main Results:

• Diploid male production significantly reduces the effective population size (Ne) in Hymenoptera.
• The reduction in Ne is more pronounced when diploid males are effectively sterile compared to inviable.
• Lower allelic diversity at the sex-determining locus amplifies the negative impact on Ne.

Conclusions:

• Complementary sex determination in Hymenoptera, coupled with diploid male production, can severely limit effective population size.
• Maintaining high allelic diversity at the sex locus is crucial for conserving Ne in these populations.
• The sterility of diploid males has a more detrimental effect on Ne than their inviability.