scholarly journals Inbreeding depression in self-incompatible North-American Arabidopsis lyrata: disentangling genomic and S-locus-specific genetic load

Heredity ◽  
2012 ◽  
Vol 110 (1) ◽  
pp. 19-28 ◽  
Author(s):  
M Stift ◽  
B D Hunter ◽  
B Shaw ◽  
A Adam ◽  
P N Hoebe ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
North American ◽  
Genetic Load ◽  
S Locus ◽  
Arabidopsis Lyrata

scholarly journals Inbreeding Depression in Small Populations of Self-Incompatible Plants

Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 1217-1229
Author(s):  
Sylvain Glémin ◽  
Thomas Bataillon ◽  
Joëlle Ronfort ◽  
Agnès Mignot ◽  
Isabelle Olivieri
Keyword(s):  
Inbreeding Depression ◽  
Genetic Load ◽  
Joint Effect ◽  
Breeding Systems ◽  
Small Populations ◽  
S Locus ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Deleterious Alleles ◽  
Negative Frequency Dependent Selection

Abstract Self-incompatibility (SI) is a widespread mechanism that prevents inbreeding in flowering plants. In many species, SI is controlled by a single locus (the S locus) where numerous alleles are maintained by negative frequency-dependent selection. Inbreeding depression, the decline in fitness of selfed individuals compared to outcrossed ones, is an essential factor in the evolution of SI systems. Conversely, breeding systems influence levels of inbreeding depression. Little is known about the joint effect of SI and drift on inbreeding depression. Here we studied, using a two-locus model, the effect of SI (frequency-dependent selection) on a locus subject to recurrent deleterious mutations causing inbreeding depression. Simulations were performed to assess the effect of population size and linkage between the two loci on the level of inbreeding depression and genetic load. We show that the sheltering of deleterious alleles linked to the S locus strengthens inbreeding depression in small populations. We discuss the implications of our results for the evolution of SI systems.

scholarly journals Inbreeding depression due to mildly deleterious mutations in finite populations: size does matter

2000 ◽  
Vol 75 (1) ◽  
pp. 75-81 ◽  
Author(s):  
THOMAS BATAILLON ◽  
MARK KIRKPATRICK
Keyword(s):  
Population Size ◽  
Inbreeding Depression ◽  
Deleterious Mutation ◽  
Large Population ◽  
Genetic Load ◽  
Breeding Systems ◽  
Deleterious Mutations ◽  
Single Locus Analysis ◽  
Population Sizes ◽  
Inbreeding Rate

We studied the effects of population size on the inbreeding depression and genetic load caused by deleterious mutations at a single locus. Analysis shows how the inbreeding depression decreases as population size becomes smaller and/or the rate of inbreeding increases. This pattern contrasts with that for the load, which increases as population size becomes smaller but decreases as inbreeding rate goes up. The depression and load both approach asymptotic limits when the population size becomes very large or very small. Numerical results show that the transition between the small and the large population regimes is quite rapid, and occurs largely over a range of population sizes that vary by a factor of 10. The effects of drift on inbreeding depression may bias some estimates of the genomic rate of deleterious mutation. These effects could also be important in the evolution of breeding systems in hermaphroditic organisms and in the conservation of endangered populations.

scholarly journals INBREEDING DEPRESSION AND GENETIC LOAD IN LABORATORY METAPOPULATIONS OF THE BUTTERFLYBICYCLUS ANYNANA

Evolution ◽  
2000 ◽  
Vol 54 (1) ◽  
pp. 218-225 ◽  
Author(s):  
Cock van Oosterhout ◽  
Wilte G. Zulstra ◽  
Marianne K. van Heuven ◽  
Paul M. Brakefield
Keyword(s):  
Inbreeding Depression ◽  
Genetic Load

scholarly journals How much gene flow is needed to avoid inbreeding depression in wild tiger populations?

2014 ◽  
Vol 281 (1789) ◽  
pp. 20133337 ◽  
Author(s):  
John Kenney ◽  
Fred W. Allendorf ◽  
Charles McDougal ◽  
James L. D. Smith
Keyword(s):  
Gene Flow ◽  
Inbreeding Depression ◽  
Negative Impact ◽  
Genetic Load ◽  
Habitat Connectivity ◽  
Medium Size ◽  
Infrastructure Development ◽  
Population Isolation ◽  
Source Populations ◽  
Seven Generations

The number and size of tiger populations continue to decline owing to habitat loss, habitat fragmentation and poaching of tigers and their prey. As a result, tiger populations have become small and highly structured. Current populations have been isolated since the early 1970s or for approximately seven generations. The objective of this study is to explore how inbreeding may be affecting the persistence of remaining tiger populations and how dispersal, either natural or artificial, may reduce the potentially detrimental effect of inbreeding depression. We developed a tiger simulation model and used published levels of genetic load in mammals to simulate inbreeding depression. Following a 50 year period of population isolation, we introduced one to four dispersing male tigers per generation to explore how gene flow from nearby populations may reduce the negative impact of inbreeding depression. For the smallest populations, even four dispersing male tigers per generation did not increase population viability, and the likelihood of extinction is more than 90% within 30 years. Unless habitat connectivity is restored or animals are artificially introduced in the next 70 years, medium size wild populations are also likely to go extinct, with only four to five of the largest wild tiger populations likely to remain extant in this same period without intervention. To reduce the risk of local extinction, habitat connectivity must be pursued concurrently with efforts to increase population size (e.g. enhance habitat quality, increase habitat availability). It is critical that infrastructure development, dam construction and other similar projects are planned appropriately so that they do not erode the extent or quality of habitat for these populations so that they can truly serve as future source populations.

Inbreeding Depression, Genetic Load, and the Evolution of Outcrossing Rates in a Multilocus System with No Linkage

Evolution ◽  
1990 ◽  
Vol 44 (6) ◽  
pp. 1469 ◽  
Author(s):  
D. Charlesworth ◽  
M. T. Morgan ◽  
B. Charlesworth
Keyword(s):  
Inbreeding Depression ◽  
Genetic Load ◽  
Outcrossing Rates
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