title: Polyandry and the decrease of a selfish genetic element in a wild house mouse population.
abstract: Despite deleterious effects on individuals, the t haplotype is a selfish genetic element present in many house mouse populations. By distorting the transmission ratio, +/t males transmit the t haplotype to up to 90% of their offspring. However, t/t individuals perish in utero. Theoretical models based on these properties predict a much higher t frequency than observed, leading to the t paradox. Here, we use empirical field data and theoretical approaches to investigate whether polyandry is a female counterstrategy against the negative fitness consequences of such distorters. We found a significant decrease of the t frequency over a period of 5.5 years that cannot be explained by the effect of transmission ratio distortion and recessive lethals, despite significantly higher life expectancy of +/t females compared to +/+ females. We quantified life-history data and homozygous and heterozygous fitness effects. Population subdivision and inbreeding were excluded as evolutionary forces influencing the t system. The possible influence of polyandry on the t system was then investigated by applying a stochastic model to this situation. Simulations show that polyandry can explain the observed t dynamics, making it a biologically plausible explanation for low t frequencies in natural populations in general.
authors: Animal Behaviour/Institute for Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland. andri.manser@ieu.uzh.ch
authors: Andri
authors: A
authors: Manser
authors: Anna K
authors: AK
authors: Lindholm
authors: Barbara
authors: B
authors: König
authors: Homayoun C
authors: HC
authors: Bagheri
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003198:Computer Simulation; D005260:Female; D005787:Gene Frequency; D056084:Genetic Fitness; D006239:Haplotypes; D008297:Male; D051379:Mice / Q000235:genetics* / Q000502:physiology; D008957:Models, Genetic; D012621:Seasons; D012726:Sexual Behavior, Animal; D013269:Stochastic Processes; D013557:Switzerland; D056427:t-Complex Genome Region