To what extent do different types of sex ratio distorters interfere?
Within the Diptera, two different selfish genetic elements are known to cause the production of female-biased sex ratios: maternally inherited bacteria that kill male zygotes (male-killers), and X chromosomes causing the degeneration of Y-bearing sperm in males (meiotic drive). We here develop a mathematical model for the dynamics of these two sex-ratio distorters where they co-occur. We show that X chromosome meiotic drive elements can be expected to substantially lower the equilibrium frequency of male-killers and can even lead to their extinction. Conversely, male-killers can also decrease the equilibrium frequency of X drivers and cause their extinction. Thus, we predict that there will be some complementarity in the incidence of X chromosome meiotic drive and male-killing in natural populations, with a lower than expected number of species bearing both elements.
Engelstädter
Jan
J
Department of Biology, University College London, Wolfson House, London NW1 2HE, United Kingdom. j.engelstaedter@ucl.ac.uk
Montenegro
Horácio
H
Hurst
Gregory D D
GD
D000818:Animals; D003198:Computer Simulation; D004175:Diptera / Q000235:genetics* / Q000382:microbiology; D008540:Meiosis / Q000235:genetics; D008957:Models, Genetic; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D012744:Sex Ratio; D020577:Wolbachia / Q000502:physiology*; D014960:X Chromosome / Q000235:genetics*