Person: Patten, Manus Michael
Loading...
Email Address
AA Acceptance Date
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Patten
First Name
Manus Michael
Name
Patten, Manus Michael
5 results
Search Results
Now showing 1 - 5 of 5
Publication Stable linkage disequilibrium owing to sexual antagonism(The Royal Society, 2010) Ubeda, F.; Haig, David; Patten, Manus MichaelLinkage disequilibrium (LD) is an association between genetic loci that is typically transient. Here, we identify a previously overlooked cause of stable LD that may be pervasive: sexual antagonism. This form of selection produces unequal allele frequencies in males and females each generation, which upon admixture at fertilization give rise to an excess of haplotypes that couple male-beneficial with male-beneficial and female-beneficial with female-beneficial alleles. Under sexual antagonism, LD is obtained for all recombination frequencies in the absence of epistasis. The extent of LD is highest at low recombination and for stronger selection. We provide a partition of the total LD into distinct com- ponents and compare our result for sexual antagonism with Li and Nei’s model of LD owing to population subdivision. Given the frequent observation of sexually antagonistic selection in natural popu- lations and the number of traits that are often involved, these results suggest a major contribution of sexual antagonism to genomic structure.Publication Maintenance or Loss of Genetic Variation Under Sexual and Parental Antagonism at a Sex-Linked Locus(Wiley-Blackwell, 2009) Patten, Manus Michael; Haig, DavidAn intralocus genetic conflict occurs when a locus is selected in opposing directions in different subsets of a population. Populations with two sexes have the potential to host a pair of distinct intralocus conflicts: sexual antagonism and parental antagonism. In this article, we examine the population genetic consequences of these conflicts for X-linked genes. Both conflicts are capable of maintaining genetic variation in a population, but to different degrees. For weak sexual antagonism, the X chromosome has a higher opportunity for polymorphism than the autosomes. For parental antagonism, there is a very limited opportunity for polymorphism on the X chromosome relative to autosomes or to sexual antagonism. X-linkage introduces an asymmetry in the inheritance and expression of sexually and parentally antagonistic genes that leads to a biased fixation of alleles with certain effects. We find little support for the commonly held intuition that the X chromosome should be biased toward fixing female beneficial alleles. Contrary to this intuition, we find that the X chromosome is biased toward fixation of male-beneficial alleles for much of the range of dominance. Additionally, we find that the X chromosome is more favorable to the fixation of alleles that are beneficial when maternally derived.Publication Reciprocally Imprinted Genes and the Response to Selection on One Sex(The Genetics Society of America, 2008) Patten, Manus Michael; Haig, DavidWe explore the theoretical consequences of limiting selection to males for the evolution of imprinted genes. We find that the efficiency of male-limited selection depends on the pattern of imprinting at an imprinted locus. When selection is strong, the maternally expressed pattern of imprinting allows faster genetic change than the reciprocal, paternally expressed pattern. When selection is relatively weak, the pattern of imprinting that permits a greater rate of genetic response to selection depends on the frequency of the favored allele: the paternally expressed pattern permits faster genetic change than does the maternally expressed pattern at low frequencies of a favored allele; at higher frequencies of a favored allele, however, the maternally expressed pattern is again more conducive to a genetic response. To our knowledge, this is the first theoretical description of a difference between the two reciprocal patterns of imprinting. The selective efficiency bias we identify between the two patterns of imprinting has implications for natural and livestock populations, which we discuss.Publication Parental sex discrimination and intralocus sexual conflict(The Royal Society, 2009) Patten, Manus Michael; Haig, DavidIntralocus sexual conflict occurs when populations segregate for alleles with opposing fitness consequences in the two sexes. This form of selection is known to be capable of maintaining genetic and fitness variation in nature, the extent of which is sensitive to the underlying genetics. We present a one-locus model of a haploid maternal effect that has sexually antagonistic consequences for offspring. The evolutionary dynamics of these maternal effects are distinct from those of haploid direct effects under sexual antagonism because the relevant genes are expressed only in females. Despite this, we find the same opportunity for sexually antagonistic polymorphism at the maternal effect locus as at a direct effect locus. Thus, sexually antagonistic maternal effects may underlie some natural genetic variation. The model we present permits alternative interpretations of how the genes are expressed and how the fitness variation is assigned, which invites a theoretical comparison to models of both imprinted genes and sex allocation.Publication Fitness Variation Due To Sexual Antagonism and Linkage Disequilibrium(Wiley-Blackwell, 2010) Patten, Manus Michael; Haig, David; Ubeda, FranciscoExtensive fitness variation for sexually antagonistic characters has been detected in nature. However, current population genetic theory suggests that sexual antagonism is unlikely to play a major role in the maintenance of variation. We present a two-locus model of sexual antagonism that is capable of explaining greater fitness variance at equilibrium than previous single-locus models. The second genetic locus provides additional fitness variance in two complementary ways. First, linked loci can maintain gene variants that are lost in single-locus models of evolution, expanding the opportunity for polymorphism. Second, linkage disequilibrium results between any two sexually antagonistic genes, producing an excess of high and low fitness haplotypes. Our results uncover a unique contribution of conflicting selection pressures to the maintenance of variation, which simpler models that neglect genetic architecture overlook.