Polyandry blocks gene drive in a wild house mouse population

Area of Science:

• Evolutionary Biology
• Population Genetics
• Behavioral Ecology

Background:

• Gene drives are genetic elements that bias inheritance, with potential applications in pest control.
• Understanding factors influencing gene drive frequency in natural populations is crucial for predicting their spread and impact.
• The t haplotype is a well-characterized gene drive found in wild house mouse populations.

Purpose of the Study:

• To investigate the impact of polyandry on the frequency of the t haplotype gene drive in a wild house mouse population.
• To assess the reproductive success of males carrying the t haplotype in the context of sperm competition.
• To provide empirical evidence on how animal mating behavior affects gene drive dynamics.

Main Methods:

• Intensive monitoring of a wild house mouse population over 4.5 years.
• Analysis of 682 litters to determine paternity and assess polyandry rates.
• Quantification of gene drive frequency and correlation with male reproductive success and mating behavior.

Main Results:

• House mice exhibit high levels of polyandry, with 47% of litters sired by multiple males.
• Males carrying the t haplotype gene drive were significantly disadvantaged in sperm competition.
• The frequency of the t haplotype gene drive declined over the observation period.

Conclusions:

• Polyandry and associated sperm competition act as significant constraints on gene drive spread in natural populations.
• Observed reproductive behaviors can counteract the theoretical transmission advantage of gene drives.
• This study provides the first direct evidence that mating behavior can impede gene drive establishment in the wild.