Carrying a selfish genetic element predicts increased migration propensity in free-living wild house mice

Abstract

Life is built on cooperation between genes, which makes it vulnerable to parasitism. Selfish genetic elements that exploit this cooperation can achieve large fitness gains by increasing their transmission relative to the rest of the genome. This leads to counter-adaptations that generate unique selection pressures on the selfish genetic element. This arms race is similar to host-parasite coevolution, as some multi-host parasites alter the host's behaviour to increase the chance of transmission to the next host. Here, we ask if, similarly to these parasites, a selfish genetic element in house mice, the t haplotype, also manipulates host behaviour, specifically the host's migration propensity. Variants of the t that manipulate migration propensity could increase in fitness in a meta-population. We show that juvenile mice carrying the t haplotype were more likely to emigrate from and were more often found as migrants within a long-term free-living house mouse population. This result may have applied relevance as the t has been proposed as a basis for artificial gene drive systems for use in population control.

Keywords: Mus musculus; arms race; intra-genomic conflict; meiotic drive; natal dispersal; t complex.

Figure 1.

Predicted probabilities of juvenile disappearance out of the study population (lines) with 95% confidence intervals and actual data points (top and bottom, jittered) of +/t (orange, dotted line) and +/+ (grey, solid line) individuals in varying juvenile population sizes (N = 2938). This example plot is based on predictions from the most informative disappearances model (model 2) for a female born in the off-season in average adult population size for no specific birthyear (fixed effects only). The vertical line indicates the mean juvenile population size.