Intragenomic Conflict

Email a friend
Contact the editor about this article
How to cite

Intragenomic Conflict

Hamish G Spencer, University of Otago, Dunedin, New Zealand

Published online: July 2003

DOI: 10.1038/npg.els.0001714

Full Article on Wiley Online Library

Abstract
Images
References

Abstract

Intragenomic conflict is the struggle for survival among different elements of the genome. In this struggle, manifested in a number of different ways, so‐called selfish genetic elements distort the standard rules of inheritance to gain a transmission advantage over other parts of the genome, often at the expense of the host organism itself.

Keywords: segregation distorters; cytoplasmic inheritance; meiosis; genomic imprinting; meiotic drive; levels of selection

	Figure 1. Meiotic drive arising from the SD complex in Drosophila melanogaster (not to scale). The primary Sd locus has two common alleles, the wild‐type Sd⁺ and the driving Sd. For drive to occur, the Sd allele must be on the same chromosome as an insensitive responder allele, Rspⁱ, and the wild‐type Sd⁺ must be linked to a sensitive responder, Rsp⁺. The effect is enhanced by linkage with, respectively, E(SD) and E(SD)⁺. Approximately 99% of the sperm generated by males that are heterozygous for the wild‐type and driving chromosomes contain the latter.
	Figure 2. Cytoplasmic incompatibility (CI) due to Wolbachia infection (represented by solid dots •) in the cytoplasm. Infected females pass on the infection via their eggs to their offspring, which are protected from any Wolbachia toxins (represented by the shaded cytoplasm) by an antidote (represented by solid crosses ×) also produced by the Wolbachia. Since the infection is not carried in the sperm, however, toxins produced early in the spermatogenesis of infected males kill offspring resulting from crosses with uninfected females.
	Figure 3. The proportion of infected cytoplasm in a population with cost‐free cytoplasmic incompatibility, according to eqn [2]. The reduction in fertility of the cross between infected males and uninfected females is given by s; curves for two values of s are shown, assuming the infection has an initial frequency of 1%.
	Figure 4. The inheritance of the PSR B‐chromosome in Nasonia vitripennis. Males arise from unfertilized eggs and are therefore haploid (and so have just one open bar representing the standard chromosomes), whereas fertilized eggs develop into diploid females (with two solid bars). When a female uses PSR‐bearing sperm to fertilize an egg, the paternally derived standard chromosomes (open bar) are eliminated and the zygote is a haploid male carrying the PSR element. Over 90% of sperm of PSR males carry the PSR chromosome.

References

Beeman RW, Friesen KS and Denell RE (1992) Maternal‐effect selfish genes in flour beetles. Science 256: 89–92.

Brookfield JFY (1991) Models of repression of transposition in P‐M hybrid disgenesis by P cytotype and by zygotically encoded repressor proteins. Genetics 128: 471–486.

Crow JF (1979) Genes that violate Mendel's rules. Scientific American 240(2): 134–146.

Engels WR (1997) Invasions of P elements. Genetics 145: 11–15.

Grun P (1976) Cytoplasmic Genetics and Evolution. New York: Columbia University Press.

Hatcher MJ (2000) Persistence of selfish genetic elements: Population structure and conflict. Trends in Ecology and Evolution 15: 271–277.

Hurst GDD, Hurst LD and Majerus MEN (1997) Cytoplasmic sex‐ratio distorters. In: O'Neill SL, Hoffmann AA and Werren JH (eds) Influential Passengers: Inherited Microorganisms and Arthropod Reproduction, pp. 125–154. Oxford: Oxford University Press.

Hurst LD (1995) Selfish genetic elements and their role in evolution: the evolution of sex and some of what that entails. Philosophical Transactions of the Royal Society of London B 349: 321–332.

Hurst LD, Atlan A and Bengtsson BO (1996) Genetic conflicts. Quarterly Review of Biology 71: 317–364.

Jones RN (1991) B‐chromosome drive. American Naturalist 137: 430–442.

Keller L and Ross KG (1998) Selfish genes: a green beard in the red fire ant. Nature 394: 573–575.

Leigh EG and Rowell TE (1995) The evolution of mutualism and other forms of harmony at various levels of biological organization. Ecologie 26: 131–158.

Lyttle TW (1991) Segregation distorters. Annual Review of Genetics 25: 511–557.

O'Neill SL, Hoffmann AA and Werren JH (eds) (1997) Influential Passengers: inherited Microorganisms and Arthropod Reproduction. Oxford: Oxford University Press.

Pomiankowski A (1999) Intragenomic conflict. In: Keller L (ed.) Levels of Selection in Evolution, pp. 121–152. Princeton, NJ: Princeton University Press.

Sober E and Wilson DS (1998) Unto Others: The Evolution and Psychology of Unselfish Behavior. Cambridge, MA: Harvard University Press.

Taylor DR, Trimble S and McCauley DE (1999) Ecological genetics of gynodioecy in Silene vulgaris: relative fitness of females and hermaphrodites during the colonization process. Evolution 53: 745–751.

Turelli M and Hoffmann AA (1991) Rapid spread of an inherited incompatibility factor in California Drosophila. Nature 353: 440–442.

Werren JH and Beukeboom LW (1993) Population genetics of a parasitic chromosome: theoretical analysis of PSR in subdivided populations. American Naturalist 142: 224–241.

Yoder JA, Walsh CP and Bestor TH (1997) Cytosine methylation and the ecology of intragenomic parasites. Trends in Genetics 13: 335–340.

Related Sub-Topics:

Contact Editor

Submit a note to the editor about this article by filling in the form below.

* Required Field

Article Title:	Intragenomic Conflict
* Name:
* E-mail:
* Note:

How to Cite

Spencer, Hamish G(Jul 2003) Intragenomic Conflict. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0001714]