Increased Infectious Disease Susceptibility Resulting from Outbreeding Depression

Autor: Emily C. Grant, Tony L. Goldberg, David P. Philipp, Julie E. Claussen, Kate R. Inendino, Todd W. Kassler
Rok vydání: 2005
Předmět:
Zdroj: Conservation Biology. 19:455-462
ISSN: 1523-1739
0888-8892
Popis: The mechanisms by which outbreeding depression leads to reduced fitness are poorly understood. We considered the hypothesis that outbreeding can depress fitness by increasing the susceptibility of hybrid individuals and populations to infectious disease. Competitive breeding trials in experimental ponds indi- cated that outbred largemouth bass ( Micropterus salmoides )c rossed from two geographically and genetically distinct populations suffered a reduction in fitness of approximately 14% relative to parental stocks. We mea- sured the comparative susceptibility of these same outbred stocks to a novel viral pathogen, largemouth bass virus. Following experimental inoculation, F2 generation hybrids suffered mortality at a rate 3.6 times higher than either F1 generation hybrids or wild-type parental fish. Analysis of viral loads indicated that viral repli- cation was more rapid in F2 fish than in F1 hybrids or wild-type parental fish. We attribute these results to the disruption of coadapted gene complexes in the immune systems of outbred fish in the F2 generation. In- creased susceptibility to infectious disease may be an important but underappreciated mechanism by which outbreeding reduces the fitness of individuals and populations and by which novel infectious diseases emerge in populations of hybrid organisms.
Databáze: OpenAIRE
Externí odkaz: