Limits...
The effect of inbreeding rate on fitness, inbreeding depression and heterosis over a range of inbreeding coefficients.

Pekkala N, Knott KE, Kotiaho JS, Nissinen K, Puurtinen M - Evol Appl (2014)

Bottom Line: The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e. inbreeding rate).Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on (i) mean fitness of a population (relative to that of an outbred control population), (ii) within-population inbreeding depression (reduction in fitness of offspring from inbred versus random mating within a population) and (iii) heterosis (increase in fitness of offspring from interpopulation versus within-population random mating).Fast inbreeding (smaller effective population size) resulted in greater reduction in population mean fitness than slow inbreeding, when populations were compared over similar inbreeding coefficients.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Environmental Science, University of Jyväskylä Jyväskylä, Finland.

ABSTRACT
Understanding the effects of inbreeding and genetic drift within populations and hybridization between genetically differentiated populations is important for many basic and applied questions in ecology and evolutionary biology. The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e. inbreeding rate). Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on (i) mean fitness of a population (relative to that of an outbred control population), (ii) within-population inbreeding depression (reduction in fitness of offspring from inbred versus random mating within a population) and (iii) heterosis (increase in fitness of offspring from interpopulation versus within-population random mating). Inbreeding rate was manipulated by using three population sizes (2, 10 and 40), and fitness was measured as offspring survival and fecundity. Fast inbreeding (smaller effective population size) resulted in greater reduction in population mean fitness than slow inbreeding, when populations were compared over similar inbreeding coefficients. Correspondingly, populations with faster inbreeding expressed more heterosis upon interpopulation hybridization. Inbreeding depression within the populations did not have a clear relationship with either the rate or the level of inbreeding.

No MeSH data available.


Related in: MedlinePlus

Inbreeding depression. Offspring fitness (A: egg-to-adult survival, B: offspring fecundity, C: total fitness) from full-sib crosses within the experimental populations (N2, N10, N40), relative to offspring fitness from random crosses within the same populations. The values are means with 95% CI, plotted against estimated inbreeding coefficient (f) of the experimental populations. Values <1 indicate inbreeding depression (for ease of interpretation, value 1.0 is indicated with solid line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4231599&req=5

fig02: Inbreeding depression. Offspring fitness (A: egg-to-adult survival, B: offspring fecundity, C: total fitness) from full-sib crosses within the experimental populations (N2, N10, N40), relative to offspring fitness from random crosses within the same populations. The values are means with 95% CI, plotted against estimated inbreeding coefficient (f) of the experimental populations. Values <1 indicate inbreeding depression (for ease of interpretation, value 1.0 is indicated with solid line).

Mentions: The estimates of within-population inbreeding depression for the N10 populations were nonsignificant at all measured inbreeding coefficients. The N40 populations showed inbreeding depression in egg-to-adult survival and in total fitness at one (f = 0.23), and in offspring fecundity at two (f = 0.23 and f = 0.35) of three inbreeding coefficients (mean value <1, CI not overlapping 1; Fig.2; Table S3). The mixed model analysis did not detect significant effects of population size or inbreeding level on inbreeding depression in any of the fitness measures (Tables3, S4 and S5).


The effect of inbreeding rate on fitness, inbreeding depression and heterosis over a range of inbreeding coefficients.

Pekkala N, Knott KE, Kotiaho JS, Nissinen K, Puurtinen M - Evol Appl (2014)

Inbreeding depression. Offspring fitness (A: egg-to-adult survival, B: offspring fecundity, C: total fitness) from full-sib crosses within the experimental populations (N2, N10, N40), relative to offspring fitness from random crosses within the same populations. The values are means with 95% CI, plotted against estimated inbreeding coefficient (f) of the experimental populations. Values <1 indicate inbreeding depression (for ease of interpretation, value 1.0 is indicated with solid line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231599&req=5

fig02: Inbreeding depression. Offspring fitness (A: egg-to-adult survival, B: offspring fecundity, C: total fitness) from full-sib crosses within the experimental populations (N2, N10, N40), relative to offspring fitness from random crosses within the same populations. The values are means with 95% CI, plotted against estimated inbreeding coefficient (f) of the experimental populations. Values <1 indicate inbreeding depression (for ease of interpretation, value 1.0 is indicated with solid line).
Mentions: The estimates of within-population inbreeding depression for the N10 populations were nonsignificant at all measured inbreeding coefficients. The N40 populations showed inbreeding depression in egg-to-adult survival and in total fitness at one (f = 0.23), and in offspring fecundity at two (f = 0.23 and f = 0.35) of three inbreeding coefficients (mean value <1, CI not overlapping 1; Fig.2; Table S3). The mixed model analysis did not detect significant effects of population size or inbreeding level on inbreeding depression in any of the fitness measures (Tables3, S4 and S5).

Bottom Line: The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e. inbreeding rate).Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on (i) mean fitness of a population (relative to that of an outbred control population), (ii) within-population inbreeding depression (reduction in fitness of offspring from inbred versus random mating within a population) and (iii) heterosis (increase in fitness of offspring from interpopulation versus within-population random mating).Fast inbreeding (smaller effective population size) resulted in greater reduction in population mean fitness than slow inbreeding, when populations were compared over similar inbreeding coefficients.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Environmental Science, University of Jyväskylä Jyväskylä, Finland.

ABSTRACT
Understanding the effects of inbreeding and genetic drift within populations and hybridization between genetically differentiated populations is important for many basic and applied questions in ecology and evolutionary biology. The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e. inbreeding rate). Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on (i) mean fitness of a population (relative to that of an outbred control population), (ii) within-population inbreeding depression (reduction in fitness of offspring from inbred versus random mating within a population) and (iii) heterosis (increase in fitness of offspring from interpopulation versus within-population random mating). Inbreeding rate was manipulated by using three population sizes (2, 10 and 40), and fitness was measured as offspring survival and fecundity. Fast inbreeding (smaller effective population size) resulted in greater reduction in population mean fitness than slow inbreeding, when populations were compared over similar inbreeding coefficients. Correspondingly, populations with faster inbreeding expressed more heterosis upon interpopulation hybridization. Inbreeding depression within the populations did not have a clear relationship with either the rate or the level of inbreeding.

No MeSH data available.


Related in: MedlinePlus