TY - JOUR

T1 - The effects of inbreeding on disease susceptibility

T2 - Gyrodactylus turnbulli infection of guppies, Poecilia reticulata

AU - Smallbone, Willow

AU - van Oosterhout, Cock

AU - Cable, Jo

PY - 2016/8

Y1 - 2016/8

N2 - Inbreeding can threaten population persistence by reducing disease resistance through the accelerated loss of gene diversity (i.e. heterozygosity). Such inbreeding depression can affect many different fitness-related traits, including survival, reproductive success, and parasite susceptibility. Empirically quantifying the effects of inbreeding on parasite resistance is therefore important for ex-situ conservation of vertebrates. The present study evaluates the disease susceptibility of individuals bred under three different breeding regimes (inbred, crossed with full siblings; control, randomly crossed mating; and fully outbred). Specifically, we examined the relationship between inbreeding coefficient (F-coefficient) and susceptibility to Gyrodactylus turnbulli infection in a live bearing vertebrate, the guppy Poecilia reticulata. Host-breeding regime significantly affected the trajectories of parasite population growth on individual fish. Inbred fish showed significantly higher mean parasite intensity than fish from the control and outbred breeding regimes, and in addition, inbred fish were slower in purging their gyrodactylid infections. We discuss the role of inbreeding on the various arms of the immune system, and argue that the increased disease susceptibility of inbred individuals could contribute to the extinction vortex. This is one of the first studies to quantify the effects of inbreeding and breeding regime on disease susceptibility in a captive bred vertebrate of wild origin, and it highlights the risks faced by small (captive-bred) populations when exposed to their native parasites.

AB - Inbreeding can threaten population persistence by reducing disease resistance through the accelerated loss of gene diversity (i.e. heterozygosity). Such inbreeding depression can affect many different fitness-related traits, including survival, reproductive success, and parasite susceptibility. Empirically quantifying the effects of inbreeding on parasite resistance is therefore important for ex-situ conservation of vertebrates. The present study evaluates the disease susceptibility of individuals bred under three different breeding regimes (inbred, crossed with full siblings; control, randomly crossed mating; and fully outbred). Specifically, we examined the relationship between inbreeding coefficient (F-coefficient) and susceptibility to Gyrodactylus turnbulli infection in a live bearing vertebrate, the guppy Poecilia reticulata. Host-breeding regime significantly affected the trajectories of parasite population growth on individual fish. Inbred fish showed significantly higher mean parasite intensity than fish from the control and outbred breeding regimes, and in addition, inbred fish were slower in purging their gyrodactylid infections. We discuss the role of inbreeding on the various arms of the immune system, and argue that the increased disease susceptibility of inbred individuals could contribute to the extinction vortex. This is one of the first studies to quantify the effects of inbreeding and breeding regime on disease susceptibility in a captive bred vertebrate of wild origin, and it highlights the risks faced by small (captive-bred) populations when exposed to their native parasites.

KW - Captive-bred

KW - Ectoparasite

KW - Gyrodactylidae

KW - Immunoresistance

KW - Inbreeding coefficient

KW - Outbred fish

UR - http://www.scopus.com/inward/record.url?scp=84965159603&partnerID=8YFLogxK

U2 - 10.1016/j.exppara.2016.04.018

DO - 10.1016/j.exppara.2016.04.018

M3 - Article

AN - SCOPUS:84965159603

VL - 167

SP - 32

EP - 37

JO - Experimental Parasitology

JF - Experimental Parasitology

SN - 0014-4894

ER -