Limits...
Sexually antagonistic "zygotic drive" of the sex chromosomes.

Rice WR, Gavrilets S, Friberg U - PLoS Genet. (2008)

Bottom Line: The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings.This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings.A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA. rice@lifesci.ucsb.edu

ABSTRACT
Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic "zygotic drive", because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans.

Show MeSH

Related in: MedlinePlus

The dynamics of the average values x and y, variances of x and y, and the average fitness of sons and daughters.(A) A run with α = 0.4 and μ = 0.00001. (B) A run with α = 0.025 and μ = 0.001. Red depicts x and daughters and blue depicts y and sons.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2596966&req=5

pgen-1000313-g005: The dynamics of the average values x and y, variances of x and y, and the average fitness of sons and daughters.(A) A run with α = 0.4 and μ = 0.00001. (B) A run with α = 0.025 and μ = 0.001. Red depicts x and daughters and blue depicts y and sons.

Mentions: Numerical simulations always show escalation of paternal effects x and y, as mutations on the X and Y giving advantage to daughters and sons, respectively, sweep through the population (see Figure 5). Depending on parameter values, the average effects x and y change in a more or less stepwise (see Figure 5A) or continuous fashion (see Figure 5B). Genetic variances Vx and Vy can be very low except for during relatively short periods of time when a new mutation goes through intermediate frequencies (see Figure 5A) or can be maintained at relatively high values (see Figure 5B). The average fitness of sons and daughters can vary significantly with periods of higher average fitness alternating between the sexes (Figure 5A).


Sexually antagonistic "zygotic drive" of the sex chromosomes.

Rice WR, Gavrilets S, Friberg U - PLoS Genet. (2008)

The dynamics of the average values x and y, variances of x and y, and the average fitness of sons and daughters.(A) A run with α = 0.4 and μ = 0.00001. (B) A run with α = 0.025 and μ = 0.001. Red depicts x and daughters and blue depicts y and sons.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2596966&req=5

pgen-1000313-g005: The dynamics of the average values x and y, variances of x and y, and the average fitness of sons and daughters.(A) A run with α = 0.4 and μ = 0.00001. (B) A run with α = 0.025 and μ = 0.001. Red depicts x and daughters and blue depicts y and sons.
Mentions: Numerical simulations always show escalation of paternal effects x and y, as mutations on the X and Y giving advantage to daughters and sons, respectively, sweep through the population (see Figure 5). Depending on parameter values, the average effects x and y change in a more or less stepwise (see Figure 5A) or continuous fashion (see Figure 5B). Genetic variances Vx and Vy can be very low except for during relatively short periods of time when a new mutation goes through intermediate frequencies (see Figure 5A) or can be maintained at relatively high values (see Figure 5B). The average fitness of sons and daughters can vary significantly with periods of higher average fitness alternating between the sexes (Figure 5A).

Bottom Line: The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings.This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings.A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA. rice@lifesci.ucsb.edu

ABSTRACT
Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic "zygotic drive", because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans.

Show MeSH
Related in: MedlinePlus