Limits...
Genetic dissimilarity between mates, but not male heterozygosity, influences divorce in schistosomes.

Beltran S, Cézilly F, Boissier J - PLoS ONE (2008)

Bottom Line: Divorce rate increased significantly when females were given the opportunity to increase genetic dissimilarity through re-mating with a new partner, independently of the intensity of male-male competition.We found however no evidence for females attempting to maximize the level of heterozygosity of their reproductive partner through divorce.Female preference for genetically dissimilar males should result in more heterozygous offspring.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Biologie et d'Ecologie Tropicale et Méditerranéenne, UMR 5244 CNRS-EPHE-UPVD, Université de Perpignan, Perpignan, France.

ABSTRACT

Background: Correlational studies strongly suggest that both genetic similarity and heterozygosity can influence female mate choice. However, the influence of each variable has usually been tested independently, although similarity and heterozygosity might be correlated. We experimentally determined the relative influence of genetic similarity and heterozygosity in divorce and re-mating in the monogamous endoparasite Schistosoma mansoni.

Methodology/principal findings: We performed sequential infections of vertebrate hosts with controlled larval populations of parasites, where sex and individual genetic diversity and similarity were predetermined before infection. Divorce rate increased significantly when females were given the opportunity to increase genetic dissimilarity through re-mating with a new partner, independently of the intensity of male-male competition. We found however no evidence for females attempting to maximize the level of heterozygosity of their reproductive partner through divorce.

Conclusions/significance: Female preference for genetically dissimilar males should result in more heterozygous offspring. Because genetic heterozygosity might partly determine the ability of parasites to counter host resistance, adaptive divorce could be an important factor in the evolutionary arms race between schistosomes and their hosts.

Show MeSH

Related in: MedlinePlus

Differences in mean divorce rate corrected by numerical ‘pressure’ (±SE), according to which sex is given opportunities to divorce.The numerical ‘pressure’ is measured as the number of individuals introduced during the second infection divided by the number of individual of the same sex introduced on the first one.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2553268&req=5

pone-0003328-g002: Differences in mean divorce rate corrected by numerical ‘pressure’ (±SE), according to which sex is given opportunities to divorce.The numerical ‘pressure’ is measured as the number of individuals introduced during the second infection divided by the number of individual of the same sex introduced on the first one.

Mentions: To that end, we performed multiple infections of definitive hosts with a first infection using parasites of both sexes followed by either male or female re-infection. Divorce rate per host ranged between 33% and 50% when mice were re-infected with males (experiment 1a), whereas it varied between 0% and 11% when mice were re-infected with females (experiment 1b) (permutation test for two independant samples, m = n = 4, P = 0.0143). After correcting for the numerical ‘pressure’ (i.e. the male-male or female-female competition measured as the number of individuals introduced during the second infection divided by the number of individual of the same sex introduced on the first one), divorce rate per host ranged between 10% and 20% when mice were re-infected with males (experiment 1a) whereas it varied between 0% and 9% when mice were re-infected with females (experiment 1b). However, the difference between the two treatments remained significant after correcting for the numerical ‘pressure’ (Fig 2; permutation test for two independent samples, m = n = 4, P = 0.0143).


Genetic dissimilarity between mates, but not male heterozygosity, influences divorce in schistosomes.

Beltran S, Cézilly F, Boissier J - PLoS ONE (2008)

Differences in mean divorce rate corrected by numerical ‘pressure’ (±SE), according to which sex is given opportunities to divorce.The numerical ‘pressure’ is measured as the number of individuals introduced during the second infection divided by the number of individual of the same sex introduced on the first one.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2553268&req=5

pone-0003328-g002: Differences in mean divorce rate corrected by numerical ‘pressure’ (±SE), according to which sex is given opportunities to divorce.The numerical ‘pressure’ is measured as the number of individuals introduced during the second infection divided by the number of individual of the same sex introduced on the first one.
Mentions: To that end, we performed multiple infections of definitive hosts with a first infection using parasites of both sexes followed by either male or female re-infection. Divorce rate per host ranged between 33% and 50% when mice were re-infected with males (experiment 1a), whereas it varied between 0% and 11% when mice were re-infected with females (experiment 1b) (permutation test for two independant samples, m = n = 4, P = 0.0143). After correcting for the numerical ‘pressure’ (i.e. the male-male or female-female competition measured as the number of individuals introduced during the second infection divided by the number of individual of the same sex introduced on the first one), divorce rate per host ranged between 10% and 20% when mice were re-infected with males (experiment 1a) whereas it varied between 0% and 9% when mice were re-infected with females (experiment 1b). However, the difference between the two treatments remained significant after correcting for the numerical ‘pressure’ (Fig 2; permutation test for two independent samples, m = n = 4, P = 0.0143).

Bottom Line: Divorce rate increased significantly when females were given the opportunity to increase genetic dissimilarity through re-mating with a new partner, independently of the intensity of male-male competition.We found however no evidence for females attempting to maximize the level of heterozygosity of their reproductive partner through divorce.Female preference for genetically dissimilar males should result in more heterozygous offspring.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Biologie et d'Ecologie Tropicale et Méditerranéenne, UMR 5244 CNRS-EPHE-UPVD, Université de Perpignan, Perpignan, France.

ABSTRACT

Background: Correlational studies strongly suggest that both genetic similarity and heterozygosity can influence female mate choice. However, the influence of each variable has usually been tested independently, although similarity and heterozygosity might be correlated. We experimentally determined the relative influence of genetic similarity and heterozygosity in divorce and re-mating in the monogamous endoparasite Schistosoma mansoni.

Methodology/principal findings: We performed sequential infections of vertebrate hosts with controlled larval populations of parasites, where sex and individual genetic diversity and similarity were predetermined before infection. Divorce rate increased significantly when females were given the opportunity to increase genetic dissimilarity through re-mating with a new partner, independently of the intensity of male-male competition. We found however no evidence for females attempting to maximize the level of heterozygosity of their reproductive partner through divorce.

Conclusions/significance: Female preference for genetically dissimilar males should result in more heterozygous offspring. Because genetic heterozygosity might partly determine the ability of parasites to counter host resistance, adaptive divorce could be an important factor in the evolutionary arms race between schistosomes and their hosts.

Show MeSH
Related in: MedlinePlus